| Type: | Package |
| Title: | Calculate Pairwise Multiple Comparisons of Mean Rank SumsExtended |
| Version: | 1.9.12 |
| Date: | 2024-09-07 |
| Description: | For one-way layout experiments the one-way ANOVA can be performed as an omnibus test. All-pairs multiple comparisons tests (Tukey-Kramer test, Scheffe test, LSD-test) and many-to-one tests (Dunnett test) for normally distributed residuals and equal within variance are available. Furthermore, all-pairs tests (Games-Howell test, Tamhane's T2 test, Dunnett T3 test, Ury-Wiggins-Hochberg test) and many-to-one (Tamhane-Dunnett Test) for normally distributed residuals and heterogeneous variances are provided. Van der Waerden's normal scores test for omnibus, all-pairs and many-to-one tests is provided for non-normally distributed residuals and homogeneous variances. The Kruskal-Wallis, BWS and Anderson-Darling omnibus test and all-pairs tests (Nemenyi test, Dunn test, Conover test, Dwass-Steele-Critchlow- Fligner test) as well as many-to-one (Nemenyi test, Dunn test, U-test) are given for the analysis of variance by ranks. Non-parametric trend tests (Jonckheere test, Cuzick test, Johnson-Mehrotra test, Spearman test) are included. In addition, a Friedman-test for one-way ANOVA with repeated measures on ranks (CRBD) and Skillings-Mack test for unbalanced CRBD is provided with consequent all-pairs tests (Nemenyi test, Siegel test, Miller test, Conover test, Exact test) and many-to-one tests (Nemenyi test, Demsar test, Exact test). A trend can be tested with Pages's test. Durbin's test for a two-way balanced incomplete block design (BIBD) is given in this package as well as Gore's test for CRBD with multiple observations per cell is given. Outlier tests, Mandel's k- and h statistic as well as functions for Type I error and Power analysis as well as generic summary, print and plot methods are provided. |
| Depends: | R (≥ 3.5.0) |
| Imports: | mvtnorm (≥ 1.0), multcompView, gmp, Rmpfr, SuppDists,kSamples (≥ 1.2.7), BWStest (≥ 0.2.1), MASS, stats |
| Suggests: | xtable, graphics, knitr, rmarkdown, car, e1071, multcomp,pwr, NSM3 |
| SystemRequirements: | gmp (>= 4.2.3), mpfr (>= 3.0.0) | file README.md |
| SystemRequirementsNote: | see >> README.md |
| SysDataCompression: | gzip |
| VignetteBuilder: | knitr, rmarkdown |
| Classification/MSC-2010: | 62J15, 62J10, 62G10, 62F03, 62G30 |
| NeedsCompilation: | yes |
| Encoding: | UTF-8 |
| LazyData: | true |
| RoxygenNote: | 7.3.1 |
| License: | GPL (≥ 3) |
| Packaged: | 2024-09-08 09:18:42 UTC; thorsten |
| Author: | Thorsten Pohlert |
| Maintainer: | Thorsten Pohlert <thorsten.pohlert@gmx.de> |
| Repository: | CRAN |
| Date/Publication: | 2024-09-08 10:10:03 UTC |
Cochran's distribution
Description
Distribution function and quantile functionfor Cochran's distribution.
Usage
qcochran(p, k, n, lower.tail = TRUE, log.p = FALSE)pcochran(q, k, n, lower.tail = TRUE, log.p = FALSE)Arguments
p | vector of probabilities. |
k | number of groups. |
n | (average) sample size of the k groups. |
lower.tail | logical; if TRUE (default),probabilities are |
log.p | logical; if TRUE, probabilities p are given as log(p). |
q | vector of quantiles. |
Value
pcochran gives the distribution function andqcochran gives the quantile function.
References
Cochran, W.G. (1941) The distribution of the largest of a set of estimatedvariances as a fraction of their total.Ann. Eugen.11, 47–52.
Wilrich, P.-T. (2011) Critical values of Mandel's h and k,Grubbs and the Cochran test statistic.Adv. Stat. Anal..doi:10.1007/s10182-011-0185-y.
See Also
Examples
qcochran(0.05, 7, 3)Grubbs D* distribution
Description
Distribution function for Grubbs D* distribution.
Usage
pdgrubbs(q, n, m = 10000, lower.tail = TRUE, log.p = FALSE)Arguments
q | vector of quantiles. |
n | total sample size. |
m | number of Monte-Carlo replicates. Defaults to |
lower.tail | logical; if TRUE (default),probabilities are |
log.p | logical; if TRUE, probabilities p are given as log(p). |
Value
pgrubbs gives the distribution function
References
Grubbs, F.E. (1950) Sample criteria for testing outlying observations,Ann. Math. Stat.21, 27–58.
Wilrich, P.-T. (2011) Critical values of Mandel's h and k,Grubbs and the Cochran test statistic,Adv. Stat. Anal..doi:10.1007/s10182-011-0185-y.
See Also
Examples
pdgrubbs(0.62, 7, 1E4)Generalized Siegel-Tukey Test of Homogeneity ofScales
Description
Performs a Siegel-Tukey k-sample rank dispersion test.
Usage
GSTTest(x, ...)## Default S3 method:GSTTest(x, g, dist = c("Chisquare", "KruskalWallis"), ...)## S3 method for class 'formula'GSTTest( formula, data, subset, na.action, dist = c("Chisquare", "KruskalWallis"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
dist | the test distribution. Defaults's to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
Meyer-Bahlburg (1970) has proposed a generalized Siegel-Tukeyrank dispersion test for thek-sample case.Likewise to thefligner.test, this testis a nonparametric test for testing the homogegeneity ofscales in several groups.Let\theta_i, and\lambda_i denotelocation and scale parameter of theith group,then for the two-tailed case, the null hypothesisH:\lambda_i / \lambda_j = 1 | \theta_i = \theta_j, ~ i \ne j istested against the alternative,A:\lambda_i / \lambda_j \ne 1with at least one inequality beeing strict.
The data are combinedly ranked according to Siegel-Tukey.The ranking is done by alternate extremes (rank 1 is lowest,2 and 3 are the two highest, 4 and 5 are the two next lowest, etc.).
Meyer-Bahlburg (1970) showed, that the Kruskal-Wallis H-testcan be employed on the Siegel-Tukey ranks.The H-statistic is assymptoticallychi-squared distributed withv = k - 1 degreeof freedom, the default test distribution is consequentlydist = "Chisquare". Ifdist = "KruskalWallis" is selected,an incomplete beta approximation is used for the calculationof p-values as implemented in the functionpKruskalWallis of the packageSuppDists.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Note
If ties are present, a tie correction is performed anda warning message is given. The GSTTest is sensitive tomedian differences, likewise to the Siegel-Tukey test.It is thus appropriate to apply this test on the residualsof a one-way ANOVA, rather than on the original data(see example).
References
H.F.L. Meyer-Bahlburg (1970), A nonparametric test for relativespread in k unpaired samples,Metrika15, 23–29.
See Also
fligner.test,pKruskalWallis,Chisquare,fligner.test
Examples
GSTTest(count ~ spray, data = InsectSprays)## as means/medians differ, apply the test to residuals## of one-way ANOVAans <- aov(count ~ spray, data = InsectSprays)GSTTest( residuals( ans) ~ spray, data =InsectSprays)Grubbs distribution
Description
Distribution function and quantile functionfor Grubbs distribution.
Usage
qgrubbs(p, n)pgrubbs(q, n, lower.tail = TRUE)Arguments
p | vector of probabilities. |
n | total sample size. |
q | vector of quantiles. |
lower.tail | logical; if TRUE (default),probabilities are |
Value
pgrubbs gives the distribution function andqgrubbs gives the quantile function.
References
Grubbs, F. E. (1950) Sample criteria for testing outlying observations.Ann. Math. Stat.21, 27–58.
Wilrich, P.-T. (2011) Critical values of Mandel's h and k,Grubbs and the Cochran test statistic.Adv. Stat. Anal..doi:10.1007/s10182-011-0185-y.
See Also
Examples
qgrubbs(0.05, 7)Extended One-Sided Studentised Range Test
Description
Performs Nashimoto-Wright's extendedone-sided studentised rangetest against an ordered alternative for normal datawith equal variances.
Usage
MTest(x, ...)## Default S3 method:MTest(x, g, alternative = c("greater", "less"), ...)## S3 method for class 'formula'MTest( formula, data, subset, na.action, alternative = c("greater", "less"), ...)## S3 method for class 'aov'MTest(x, alternative = c("greater", "less"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
The procedure uses the property of a simple order,\theta_m' - \mu_m \le \mu_j - \mu_i \le \mu_l' - \mu_l\qquad (l \le i \le m~\mathrm{and}~ m' \le j \le l').The null hypothesis H_{ij}: \mu_i = \mu_j is tested againstthe alternative A_{ij}: \mu_i < \mu_j for any1 \le i < j \le k.
The all-pairs comparisons test statistics for a balanced design are
\hat{h}_{ij} = \max_{i \le m < m' \le j} \frac{\left(\bar{x}_{m'} - \bar{x}_m \right)} {s_{\mathrm{in}} / \sqrt{n}},
withn = n_i; ~ N = \sum_i^k n_i ~~ (1 \le i \le k),\bar{x}_i the arithmetic mean of theith group,ands_{\mathrm{in}}^2 the within ANOVA variance. The null hypothesis is rejected,if\hat{h} > h_{k,\alpha,v}, withv = N - kdegree of freedom.
For the unbalanced case with moderate imbalance the test statistic is
\hat{h}_{ij} = \max_{i \le m < m' \le j} \frac{\left(\bar{x}_{m'} - \bar{x}_m \right)} {s_{\mathrm{in}} \left(1/n_m + 1/n_{m'}\right)^{1/2}},
The null hypothesis is rejected, if\hat{h}_{ij} > h_{k,\alpha,v} / \sqrt{2}.
The function does not return p-values. Instead the critical h-valuesas given in the tables of Hayter (1990) for\alpha = 0.05 (one-sided)are looked up according to the number of groups (k) andthe degree of freedoms (v).
Value
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated statistic(s)
- crit.value
critical values for
\alpha = 0.05.- alternative
a character string describing the alternative hypothesis.
- parameter
the parameter(s) of the test distribution.
- dist
a string that denotes the test distribution.
There are print and summary methods available.
Note
The function will give a warning for the unbalanced case and returns thecritical valueh_{k,\alpha,\infty} / \sqrt{2}.
References
Hayter, A. J.(1990) A One-Sided Studentised RangeTest for Testing Against a Simple Ordered Alternative,Journal of the American Statistical Association85, 778–785.
Nashimoto, K., Wright, F.T., (2005) Multiple comparison proceduresfor detecting differences in simply ordered means.Comput. Statist. Data Anal.48, 291–306.
See Also
Examples
##md <- aov(weight ~ group, PlantGrowth)anova(md)osrtTest(md)MTest(md)Mandel's h Distribution
Description
Distribution function and quantile functionfor Mandel's h distribution.
Usage
qmandelh(p, k, lower.tail = TRUE, log.p = FALSE)pmandelh(q, k, lower.tail = TRUE, log.p = FALSE)Arguments
p | vector of probabilities. |
k | number of groups. |
lower.tail | logical; if TRUE (default),probabilities are |
log.p | logical; if |
q | vector of quantiles. |
Value
pmandelh gives the distribution function andqmandelh gives the quantile function.
Source
The code forpmandelh was taken from:
Stephen L R Ellison. (2017). metRology: Support for MetrologicalApplications. R package version 0.9-26-2.https://CRAN.R-project.org/package=metRology
References
Practice E 691 (2005)Standard Practice forConducting an Interlaboratory Study to Determine thePrecision of a Test Method, ASTM International.
See Also
Examples
## We need a two-sided upper-tail quantileqmandelh(p = 0.005/2, k = 7, lower.tail=FALSE)Mandel's k Distribution
Description
Distribution function and quantile functionfor Mandel's k distribution.
Usage
qmandelk(p, k, n, lower.tail = TRUE, log.p = FALSE)pmandelk(q, k, n, lower.tail = TRUE, log.p = FALSE)Arguments
p | vector of probabilities. |
k | number of groups. |
n | number of replicates per group. |
lower.tail | logical; if TRUE (default),probabilities are |
log.p | logical; if |
q | vector of quantiles. |
Value
pmandelk gives the distribution function andqmandelk gives the quantile function.
Source
The code forpmandelk was taken from:
Stephen L R Ellison. (2017). metRology: Support for MetrologicalApplications. R package version 0.9-26-2.https://CRAN.R-project.org/package=metRology
Note
The functions are only appropriate for balanced designs.
References
Practice E 691 (2005)Standard Practice forConducting an Interlaboratory Study to Determine thePrecision of a Test Method, ASTM International.
See Also
Examples
qmandelk(0.005, 7, 3, lower.tail=FALSE)All-Pairs Comparisons for Simply Ordered Mean Ranksums
Description
Performs Nashimoto and Wright's all-pairs comparison procedurefor simply ordered mean ranksums.
Usage
NPMTest(x, ...)## Default S3 method:NPMTest( x, g, alternative = c("greater", "less"), method = c("look-up", "boot", "asympt"), nperm = 10000, ...)## S3 method for class 'formula'NPMTest( formula, data, subset, na.action, alternative = c("greater", "less"), method = c("look-up", "boot", "asympt"), nperm = 10000, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
method | a character string specifying the test statistic to use.Defaults to |
nperm | number of permutations for the asymptotic permutation test.Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
The procedure uses the property of a simple order,\theta_m' - \theta_m \le \theta_j - \theta_i \le \theta_l' - \theta_l\qquad (l \le i \le m~\mathrm{and}~ m' \le j \le l').The null hypothesis H_{ij}: \theta_i = \theta_j is tested againstthe alternative A_{ij}: \theta_i < \theta_j for any1 \le i < j \le k.
The all-pairs comparisons test statistics for a balanced design are
\hat{h}_{ij} = \max_{i \le m < m' \le j} \frac{\left(\bar{R}_{m'} - \bar{R}_m \right)}{\sigma_a / \sqrt{n}},
withn = n_i; ~ N = \sum_i^k n_i ~~ (1 \le i \le k),\bar{R}_i the mean rank for theith group,and\sigma_a = \sqrt{N \left(N + 1 \right) / 12}. The null hypothesis is rejected,ifh_{ij} > h_{k,\alpha,\infty}.
For the unbalanced case with moderate imbalance the test statistic is
\hat{h}_{ij} = \max_{i \le m < m' \le j} \frac{\left(\bar{R}_{m'} - \bar{R}_m \right)} {\sigma_a \left(1/n_m + 1/n_{m'}\right)^{1/2}},
The null hypothesis is rejected, if\hat{h}_{ij} > h_{k,\alpha,\infty} / \sqrt{2}.
Ifmethod = "look-up" the function will not returnp-values. Instead the critical h-valuesas given in the tables of Hayter (1990) for\alpha = 0.05 (one-sided)are looked up according to the number of groups (k) andthe degree of freedoms (v = \infty).
Ifmethod = "boot" an asymetric permutation testis conducted andp-values is returned.
Ifmethod = "asympt" is selected the asymptoticp-value is estimated as implemented in thefunctionpHayStonLSA of the packageNSM3.
Value
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated statistic(s)
- crit.value
critical values for
\alpha = 0.05.- alternative
a character string describing the alternative hypothesis.
- parameter
the parameter(s) of the test distribution.
- dist
a string that denotes the test distribution.
There are print and summary methods available.
Either a list of class"PMCMR" or alist with class"osrt" that contains the followingcomponents:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated statistic(s)
- crit.value
critical values for
\alpha = 0.05.- alternative
a character string describing the alternative hypothesis.
- parameter
the parameter(s) of the test distribution.
- dist
a string that denotes the test distribution.
There are print and summary methods available.
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Note
The function will give a warning for the unbalanced case and returns thecritical valueh_{k,\alpha,\infty} / \sqrt{2}.
Source
Ifmethod = "asympt" is selected, this function callsan internal probability functionpHS. The GPL-2 code forthis function was taken frompHayStonLSA of thethe packageNSM3:
Grant Schneider, Eric Chicken and Rachel Becvarik (2020) NSM3:Functions and Datasets to Accompany Hollander, Wolfe, andChicken - Nonparametric Statistical Methods, Third Edition. Rpackage version 1.15.https://CRAN.R-project.org/package=NSM3
References
Hayter, A. J.(1990) A One-Sided Studentised RangeTest for Testing Against a Simple Ordered Alternative,Journal of the American Statistical Association85, 778–785.
Nashimoto, K., Wright, F.T. (2007)Nonparametric Multiple-Comparison Methods for SimplyOrdered Medians.Comput Stat Data Anal51, 5068–5076.
See Also
Examples
## Example from Shirley (1977)## Reaction times of mice to stimuli to their tails.x <- c(2.4, 3, 3, 2.2, 2.2, 2.2, 2.2, 2.8, 2, 3, 2.8, 2.2, 3.8, 9.4, 8.4, 3, 3.2, 4.4, 3.2, 7.4, 9.8, 3.2, 5.8, 7.8, 2.6, 2.2, 6.2, 9.4, 7.8, 3.4, 7, 9.8, 9.4, 8.8, 8.8, 3.4, 9, 8.4, 2.4, 7.8)g <- gl(4, 10)## Shirley's test## one-sided test using look-up tableshirleyWilliamsTest(x ~ g, alternative = "greater")## Chacko's global hypothesis test for 'greater'chackoTest(x , g)## post-hoc test, default is standard normal distribution (NPT'-test)summary(chaAllPairsNashimotoTest(x, g, p.adjust.method = "none"))## same but h-distribution (NPY'-test)chaAllPairsNashimotoTest(x, g, dist = "h")## NPM-testNPMTest(x, g)## Hayter-Stone testhayterStoneTest(x, g)## all-pairs comparisonshsAllPairsTest(x, g)Pentosan Dataset
Description
A benchmark dataset of an interlaboratory study fordetermining the precision of a test methodon several levels of the material Pentosan.
Format
A data frame with 189 obs. of 3 variables:
- value
numeric, test result (no unit specified)
- lab
factor, identifier of the lab (1–7)
- material
factor, identifier of the level of the material (A–I)
Source
Tab. 8, Practice E 691, 2005,Standard Practice forConducting an Interlaboratory Study to Determine thePrecision of a Test Method, ASTM International.
Anderson-Darling All-Pairs Comparison Test
Description
Performs Anderson-Darling all-pairs comparison test.
Usage
adAllPairsTest(x, ...)## Default S3 method:adAllPairsTest(x, g, p.adjust.method = p.adjust.methods, ...)## S3 method for class 'formula'adAllPairsTest( formula, data, subset, na.action, p.adjust.method = p.adjust.methods, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
p.adjust.method | method for adjusting p values (see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith non-normally distributed residuals Anderson-Darling'sall-pairs comparison test can be used. A total ofm = k(k-1)/2hypotheses can be tested. The null hypothesisH_{ij}: F_i(x) = F_j(x) is tested in the two-tailed testagainst the alternativeA_{ij}: F_i(x) \ne F_j(x), ~~ i \ne j.
This function is a wrapper function that sequentiallycallsadKSampleTest for each pair.The calculated p-values forPr(>|T2N|)can be adjusted to account for Type I error multiplicityusing any method as implemented inp.adjust.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Scholz, F.W., Stephens, M.A. (1987) K-Sample Anderson-Darling Tests.Journal of the American Statistical Association82, 918–924.
See Also
adKSampleTest,adManyOneTest,ad.pval.
Examples
adKSampleTest(count ~ spray, InsectSprays)out <- adAllPairsTest(count ~ spray, InsectSprays, p.adjust="holm")summary(out)summaryGroup(out)Anderson-Darling k-Sample Test
Description
Performs Anderson-Darling k-sample test.
Usage
adKSampleTest(x, ...)## Default S3 method:adKSampleTest(x, g, ...)## S3 method for class 'formula'adKSampleTest(formula, data, subset, na.action, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
The null hypothesis, H_0: F_1 = F_2 = \ldots = F_kis tested against the alternative,H_\mathrm{A}: F_i \ne F_j ~~(i \ne j), with at leastone unequality beeing strict.
This function only evaluates version 1 of the k-sample Anderson-Darlingtest (i.e. Eq. 6) of Scholz and Stephens (1987).The p-values are estimated with the extended empirical functionas implemented inad.pval ofthe packagekSamples.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
References
Scholz, F.W., Stephens, M.A. (1987) K-Sample Anderson-Darling Tests.Journal of the American Statistical Association82, 918–924.
See Also
adAllPairsTest,adManyOneTest,ad.pval.
Examples
## Hollander & Wolfe (1973), 116.## Mucociliary efficiency from the rate of removal of dust in normal## subjects, subjects with obstructive airway disease, and subjects## with asbestosis.x <- c(2.9, 3.0, 2.5, 2.6, 3.2) # normal subjectsy <- c(3.8, 2.7, 4.0, 2.4) # with obstructive airway diseasez <- c(2.8, 3.4, 3.7, 2.2, 2.0) # with asbestosisg <- factor(x = c(rep(1, length(x)), rep(2, length(y)), rep(3, length(z))), labels = c("ns", "oad", "a"))dat <- data.frame( g = g, x = c(x, y, z))## AD-TestadKSampleTest(x ~ g, data = dat)## BWS-TestbwsKSampleTest(x ~ g, data = dat)## Kruskal-Test## Using incomplete beta approximationkruskalTest(x ~ g, dat, dist="KruskalWallis")## Using chisquare distributionkruskalTest(x ~ g, dat, dist="Chisquare")## Not run: ## Check with kruskal.test from R statskruskal.test(x ~ g, dat)## End(Not run)## Using Conover's FkruskalTest(x ~ g, dat, dist="FDist")## Not run: ## Check with aov on ranksanova(aov(rank(x) ~ g, dat))## Check with oneway.testoneway.test(rank(x) ~ g, dat, var.equal = TRUE)## End(Not run)## Median Test asymptoticmedianTest(x ~ g, dat)## Median Test with simulated p-valuesset.seed(112)medianTest(x ~ g, dat, simulate.p.value = TRUE)Anderson-Darling Many-To-One Comparison Test
Description
Performs Anderson-Darling many-to-one comparison test.
Usage
adManyOneTest(x, ...)## Default S3 method:adManyOneTest(x, g, p.adjust.method = p.adjust.methods, ...)## S3 method for class 'formula'adManyOneTest( formula, data, subset, na.action, p.adjust.method = p.adjust.methods, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
p.adjust.method | method for adjustingp values (see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For many-to-one comparisons (pairwise comparisons with one control)in an one-factorial layout with non-normally distributedresiduals Anderson-Darling's non-parametric test can be performed.Let there bek groups including the control,then the number of treatment levels ism = k - 1.Thenm pairwise comparisons can be performed betweenthei-th treatment level and the control.H_i: F_0 = F_i is tested in the two-tailed case againstA_i: F_0 \ne F_i, ~~ (1 \le i \le m).
This function is a wrapper function that sequentiallycallsadKSampleTest for each pair.The calculated p-values forPr(>|T2N|)can be adjusted to account for Type I error inflationusing any method as implemented inp.adjust.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Note
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
Scholz, F.W., Stephens, M.A. (1987) K-Sample Anderson-Darling Tests.Journal of the American Statistical Association82, 918–924.
See Also
adKSampleTest,adAllPairsTest,ad.pval.
Examples
## Data set PlantGrowth## Global testadKSampleTest(weight ~ group, data = PlantGrowth)##ans <- adManyOneTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)Algae Growth Inhibition Data Set
Description
A dose-response experiment was conducted using Atrazineat 9 different dose-levels including the zero-dose controland the biomass of algae (Selenastrumcapricornutum) as the response variable. Three replicateswere measured at day 0, 1 and 2. The fluorescence method (Mayer etal. 1997) was applied to measure biomass.
Format
A data frame with 22 observations on the following 10 variables.
- concentration
a numeric vector of dose value in mg / L
- Day.0
a numeric vector, total biomass
- Day.0.1
a numeric vector, total biomass
- Day.0.2
a numeric vector, total biomass
- Day.1
a numeric vector, total biomass
- Day.1.1
a numeric vector, total biomass
- Day.1.2
a numeric vector, total biomass
- Day.2
a numeric vector, total biomass
- Day.2.1
a numeric vector, total biomass
- Day.2.2
a numeric vector, total biomass
Source
ENV/JM/MONO(2006)18/ANN, page 24.
References
OECD (ed. 2006)Current approaches in the statistical analysisof ecotoxicity data: A guidance to application - Annexes, OECD Serieson testing and assessment, No. 54, (ENV/JM/MONO(2006)18/ANN).
See Also
demo(algae)
Plotting PMCMR Objects
Description
Plots a bar-plot for objects of class"PMCMR".
Usage
barPlot(x, alpha = 0.05, ...)Arguments
x | an object of class |
alpha | the selected alpha-level. Defaults to 0.05. |
... | further arguments for method |
Value
A barplot where the height of the bars corresponds to the arithmeticmean. The extend of the whiskers are\pm z_{(1-\alpha/2)}\times s_{\mathrm{E},i}, where the latter denotes the standard errorof theith group. Symbolic letters are depicted on top of the bars,whereas different letters indicate significant differences betweengroups for the selected level of alpha.
Note
The barplot is strictly spoken only valid for normal data, asthe depicted significance intervall implies symetry.
Examples
## data set chickwtsans <- tukeyTest(weight ~ feed, data = chickwts)barPlot(ans)BWS All-Pairs Comparison Test
Description
Performs Baumgartner-Weiß-Schindler all-pairs comparison test.
Usage
bwsAllPairsTest(x, ...)## Default S3 method:bwsAllPairsTest( x, g, method = c("BWS", "Murakami"), p.adjust.method = p.adjust.methods, ...)## S3 method for class 'formula'bwsAllPairsTest( formula, data, subset, na.action, method = c("BWS", "Murakami"), p.adjust.method = p.adjust.methods, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
method | a character string specifying the test statistic to use. Defaults to |
p.adjust.method | method for adjusting p values (see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith non-normally distributed residuals Baumgartner-Weiß-Schindlerall-pairs comparison test can be used. A total ofm = k(k-1)/2hypotheses can be tested. The null hypothesisH_{ij}: F_i(x) = F_j(x) is tested in the two-tailed testagainst the alternativeA_{ij}: F_i(x) \ne F_j(x), ~~ i \ne j.
This function is a wrapper function that sequentiallycallsbws_test for each pair.The default test method ("BWS") is the originalBaumgartner-Weiß-Schindler test statistic B. Formethod == "Murakami" it is the modified BWS statisticdenoted B*. The calculated p-values forPr(>|B|)orPr(>|B*|) can be adjusted to account for Type I errorinflation using any method as implemented inp.adjust.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Baumgartner, W., Weiss, P., Schindler, H. (1998) A nonparametric test for thegeneral two-sample problem,Biometrics54, 1129–1135.
Murakami, H. (2006) K-sample rank test based on modified Baumgartner statistic and its powercomparison,J. Jpn. Comp. Statist.19, 1–13.
See Also
Examples
out <- bwsAllPairsTest(count ~ spray, InsectSprays, p.adjust="holm")summary(out)summaryGroup(out)Murakami's k-Sample BWS Test
Description
Performs Murakami's k-Sample BWS Test.
Usage
bwsKSampleTest(x, ...)## Default S3 method:bwsKSampleTest(x, g, nperm = 1000, ...)## S3 method for class 'formula'bwsKSampleTest(formula, data, subset, na.action, nperm = 1000, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
nperm | number of permutations for the assymptotic permutation test.Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
LetX_{ij} ~ (1 \le i \le k,~ 1 \le 1 \le n_i) denote anidentically and independently distributed variable that is obtainedfrom an unknown continuous distributionF_i(x). LetR_{ij}be the rank ofX_{ij}, whereX_{ij} is jointly rankedfrom1 toN, ~ N = \sum_{i=1}^k n_i.In thek-sample test the null hypothesis, H:F_i = F_jis tested against the alternative,A:F_i \ne F_j ~~(i \ne j) with at least one inequalitybeeing strict. Murakami (2006) has generalizedthe two-sample Baumgartner-Weiß-Schindler test(Baumgartner et al. 1998) and proposed amodified statisticB_k^* defined by
B_{k}^* = \frac{1}{k}\sum_{i=1}^k\left\{\frac{1}{n_i} \sum_{j=1}^{n_i} \frac{(R_{ij} - \mathsf{E}[R_{ij}])^2} {\mathsf{Var}[R_{ij}]}\right\},
where
\mathsf{E}[R_{ij}] = \frac{N + 1}{n_i + 1} j
and
\mathsf{Var}[R_{ij}] = \frac{j}{n_i + 1} \left(1 - \frac{j}{n_i + 1}\right)\frac{\left(N-n_i\right)\left(N+1\right)}{n_i + 2}.
Thep-values are estimated via an assymptotic boot-strap method.It should be noted that theB_k^* detects both differences in theunknown location parameters and / or differencesin the unknown scale parameters of thek-samples.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Note
One may increase the number of permutations to e.g.nperm = 10000in order to get more precise p-values. However, this will be onthe expense of computational time.
References
Baumgartner, W., Weiss, P., Schindler, H. (1998) A nonparametric test for thegeneral two-sample problem,Biometrics54, 1129–1135.
Murakami, H. (2006) K-sample rank test based on modified Baumgartner statistic and its powercomparison,J. Jpn. Comp. Statist.19, 1–13.
See Also
sample,bwsAllPairsTest,bwsManyOneTest.
Examples
## Hollander & Wolfe (1973), 116.## Mucociliary efficiency from the rate of removal of dust in normal## subjects, subjects with obstructive airway disease, and subjects## with asbestosis.x <- c(2.9, 3.0, 2.5, 2.6, 3.2) # normal subjectsy <- c(3.8, 2.7, 4.0, 2.4) # with obstructive airway diseasez <- c(2.8, 3.4, 3.7, 2.2, 2.0) # with asbestosisg <- factor(x = c(rep(1, length(x)), rep(2, length(y)), rep(3, length(z))), labels = c("ns", "oad", "a"))dat <- data.frame( g = g, x = c(x, y, z))## AD-TestadKSampleTest(x ~ g, data = dat)## BWS-TestbwsKSampleTest(x ~ g, data = dat)## Kruskal-Test## Using incomplete beta approximationkruskalTest(x ~ g, dat, dist="KruskalWallis")## Using chisquare distributionkruskalTest(x ~ g, dat, dist="Chisquare")## Not run: ## Check with kruskal.test from R statskruskal.test(x ~ g, dat)## End(Not run)## Using Conover's FkruskalTest(x ~ g, dat, dist="FDist")## Not run: ## Check with aov on ranksanova(aov(rank(x) ~ g, dat))## Check with oneway.testoneway.test(rank(x) ~ g, dat, var.equal = TRUE)## End(Not run)## Median Test asymptoticmedianTest(x ~ g, dat)## Median Test with simulated p-valuesset.seed(112)medianTest(x ~ g, dat, simulate.p.value = TRUE)BWS Many-To-One Comparison Test
Description
Performs Baumgartner-Weiß-Schindler many-to-one comparison test.
Usage
bwsManyOneTest(x, ...)## Default S3 method:bwsManyOneTest( x, g, alternative = c("two.sided", "greater", "less"), method = c("BWS", "Murakami", "Neuhauser"), p.adjust.method = p.adjust.methods, ...)## S3 method for class 'formula'bwsManyOneTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), method = c("BWS", "Murakami", "Neuhauser"), p.adjust.method = p.adjust.methods, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
method | a character string specifying the test statistic to use. Defaults to |
p.adjust.method | method for adjusting p values (see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For many-to-one comparisons (pairwise comparisons with one control)in an one-factorial layout with non-normally distributedresiduals Baumgartner-Weiß-Schindler's non-parametric test can be performed.Let there bek groups including the control,then the number of treatment levels ism = k - 1.Thenm pairwise comparisons can be performed betweenthei-th treatment level and the control.H_i: F_0 = F_i is tested in the two-tailed case againstA_i: F_0 \ne F_i, ~~ (1 \le i \le m).
This function is a wrapper function that sequentiallycallsbws_stat andbws_cdffor each pair. For the default test method ("BWS") the originalBaumgartner-Weiß-Schindler test statistic B and its corresponding Pr(>|B|)is calculated. Formethod == "BWS" only a two-sided test is possible.
Formethod == "Murakami" the modified BWS statisticdenoted B* and its corresponding Pr(>|B*|) is computed by sequentially callingmurakami_stat andmurakami_cdf.Formethod == "Murakami" only a two-sided test is possible.
Ifalternative == "greater" then the alternative, if onepopulation is stochastically larger than the other is tested:H_i: F_0 = F_i against A_i: F_0 \ge F_i, ~~ (1 \le i \le m).The modified test-statistic B* according to Neuhäuser (2001) and itscorresponding Pr(>B*) or Pr(<B*) is computed by sequentally callingmurakami_stat andmurakami_cdfwithflavor = 2.
The p-values can be adjusted to account for Type I errorinflation using any method as implemented inp.adjust.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Note
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
Baumgartner, W., Weiss, P., Schindler, H. (1998) A nonparametric test for thegeneral two-sample problem,Biometrics54, 1129–1135.
Murakami, H. (2006) K-sample rank test based on modified Baumgartner statistic and its powercomparison,J Jpn Comp Statist19, 1–13.
Neuhäuser, M. (2001) One-Side Two-Sample and Trend Tests Based on a ModifiedBaumgartner-Weiss-Schindler Statistic.J Nonparametric Stat13, 729–739.
See Also
murakami_stat,murakami_cdf,bws_stat,bws_cdf.
Examples
out <- bwsManyOneTest(weight ~ group, PlantGrowth, p.adjust="holm")summary(out)## A two-sample testset.seed(1245)x <- c(rnorm(20), rnorm(20,0.3))g <- gl(2, 20)summary(bwsManyOneTest(x ~ g, alternative = "less", p.adjust="none"))summary(bwsManyOneTest(x ~ g, alternative = "greater", p.adjust="none"))## Not run: ## Check with the implementation in package BWStestBWStest::bws_test(x=x[g==1], y=x[g==2], alternative = "less")BWStest::bws_test(x=x[g==1], y=x[g==2], alternative = "greater")## End(Not run)Testing against Ordered Alternatives (Murakami's BWS Trend Test)
Description
Performs Murakami's modified Baumgartner-Weiß-Schindlertest for testing against ordered alternatives.
Usage
bwsTrendTest(x, ...)## Default S3 method:bwsTrendTest(x, g, nperm = 1000, ...)## S3 method for class 'formula'bwsTrendTest(formula, data, subset, na.action, nperm = 1000, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
nperm | number of permutations for the assymptotic permutation test.Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
The null hypothesis, H_0: F_1(u) = F_2(u) = \ldots = F_k(u) ~~ u \in Ris tested against a simple order hypothesis,H_\mathrm{A}: F_1(u) \le F_2(u) \le \ldots \leF_k(u),~F_1(u) < F_k(u), ~~ u \in R.
The p-values are estimated through an assymptotic boot-strap methodusing the functionsample.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Note
One may increase the number of permutations to e.g.nperm = 10000in order to get more precise p-values. However, this will be onthe expense of computational time.
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
Baumgartner, W., Weiss, P., Schindler, H. (1998) A nonparametric test for thegeneral two-sample problem,Biometrics54, 1129–1135.
Murakami, H. (2006) K-sample rank test based on modified Baumgartner statistic and its powercomparison,J Jpn Comp Statist19, 1–13.
Neuhäuser, M. (2001) One-Side Two-Sample and Trend Tests Based on a ModifiedBaumgartner-Weiss-Schindler Statistic.J Nonparametric Stat13, 729–739.
See Also
sample,bwsAllPairsTest,bwsManyOneTest.
kruskalTest andshirleyWilliamsTestof the packagePMCMRplus,kruskal.test of the librarystats.
Examples
## Example from Sachs (1997, p. 402)x <- c(106, 114, 116, 127, 145, 110, 125, 143, 148, 151, 136, 139, 149, 160, 174)g <- gl(3,5)levels(g) <- c("A", "B", "C")## Chacko's testchackoTest(x, g)## Cuzick's testcuzickTest(x, g)## Johnson-Mehrotra testjohnsonTest(x, g)## Jonckheere-Terpstra testjonckheereTest(x, g)## Le's testleTest(x, g)## Spearman type testspearmanTest(x, g)## Murakami's BWS trend testbwsTrendTest(x, g)## Fligner-Wolfe testflignerWolfeTest(x, g)## Shan-Young-Kang testshanTest(x, g)All-Pairs Comparisons for Simply Ordered Mean Ranksums
Description
Performs Nashimoto and Wright's all-pairs comparison procedurefor simply ordered mean ranksums (NPT'-test and NPY'-test).
According to the authors, the procedure shall only beapplied after Chacko's test (seechackoTest) indicatesglobal significance.
Usage
chaAllPairsNashimotoTest(x, ...)## Default S3 method:chaAllPairsNashimotoTest( x, g, p.adjust.method = c(p.adjust.methods), alternative = c("greater", "less"), dist = c("Normal", "h"), ...)## S3 method for class 'formula'chaAllPairsNashimotoTest( formula, data, subset, na.action, p.adjust.method = c(p.adjust.methods), alternative = c("greater", "less"), dist = c("Normal", "h"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
p.adjust.method | method for adjusting p values. Ignored if |
alternative | the alternative hypothesis. Defaults to |
dist | the test distribution. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
The modified procedure uses the property of a simple order,\theta_m' - \theta_m \le \theta_j - \theta_i \le \theta_l' - \theta_l\qquad (l \le i \le m~\mathrm{and}~ m' \le j \le l').The null hypothesis H_{ij}: \theta_i = \theta_j is tested againstthe alternative A_{ij}: \theta_i < \theta_j for any1 \le i < j \le k.
LetR_{ij} be the rank ofX_{ij},whereX_{ij} is jointly rankedfrom\left\{1, 2, \ldots, N \right\}, ~~ N = \sum_{i=1}^k n_i,then the test statistics for all-pairs comparisonsand a balanced design is calculated as
\hat{T}_{ij} = \max_{i \le m < m' \le j} \frac{\left(\bar{R}_{m'} - \bar{R}_m \right)} {\sigma_a / \sqrt{n}},
withn = n_i; ~ N = \sum_i^k n_i ~~ (1 \le i \le k),\bar{R}_ithe mean rank for theith group,and the expected variance (without ties)\sigma_a^2 = N \left(N + 1 \right) / 12.
For the NPY'-test (dist = "h"), ifT_{ij} > h_{k-1,\alpha,\infty}.
For the unbalanced case with moderate imbalance the test statistic is
\hat{T}_{ij} = \max_{i \le m < m' \le j} \frac{\left(\bar{R}_{m'} - \bar{R}_m \right)} {\sigma_a \left(1/n_m + 1/n_{m'}\right)^{1/2}},
For the NPY'-test (dist="h") the null hypothesis is rejected in an unbalanced design,if\hat{T}_{ij} > h_{k,\alpha,\infty} / \sqrt{2}.In case of a NPY'-test, the function does not return p-values. Instead the critical h-valuesas given in the tables of Hayter (1990) for\alpha = 0.05 (one-sided)are looked up according to the number of groups (k-1) andthe degree of freedoms (v = \infty).
For the NPT'-test (dist = "Normal"), the null hypothesis is rejected, ifT_{ij} > \sqrt{2} t_{\alpha,\infty} = \sqrt{2} z_\alpha. Although Nashimoto and Wright (2005) originally did not use any p-adjustment,any method as available byp.adjust.methods canbe selected for the adjustment of p-values estimated fromthe standard normal distribution.
Value
Either a list of class"osrt" ifdist = "h" or a listof class"PMCMR" ifdist = "Normal".
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated statistic(s)
- crit.value
critical values for
\alpha = 0.05.- alternative
a character string describing the alternative hypothesis.
- parameter
the parameter(s) of the test distribution.
- dist
a string that denotes the test distribution.
There are print and summary methods available.
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Note
The function will give a warning for the unbalanced case and returns thecritical valueh_{k-1,\alpha,\infty} / \sqrt{2} if applicable.
References
Hayter, A. J.(1990) A One-Sided Studentised RangeTest for Testing Against a Simple Ordered Alternative,J Amer Stat Assoc85, 778–785.
Nashimoto, K., Wright, F.T. (2007)Nonparametric Multiple-Comparison Methods for Simply Ordered Medians.Comput Stat Data Anal51, 5068–5076.
See Also
Examples
## Example from Shirley (1977)## Reaction times of mice to stimuli to their tails.x <- c(2.4, 3, 3, 2.2, 2.2, 2.2, 2.2, 2.8, 2, 3, 2.8, 2.2, 3.8, 9.4, 8.4, 3, 3.2, 4.4, 3.2, 7.4, 9.8, 3.2, 5.8, 7.8, 2.6, 2.2, 6.2, 9.4, 7.8, 3.4, 7, 9.8, 9.4, 8.8, 8.8, 3.4, 9, 8.4, 2.4, 7.8)g <- gl(4, 10)## Shirley's test## one-sided test using look-up tableshirleyWilliamsTest(x ~ g, alternative = "greater")## Chacko's global hypothesis test for 'greater'chackoTest(x , g)## post-hoc test, default is standard normal distribution (NPT'-test)summary(chaAllPairsNashimotoTest(x, g, p.adjust.method = "none"))## same but h-distribution (NPY'-test)chaAllPairsNashimotoTest(x, g, dist = "h")## NPM-testNPMTest(x, g)## Hayter-Stone testhayterStoneTest(x, g)## all-pairs comparisonshsAllPairsTest(x, g)Testing against Ordered Alternatives (Chacko's Test)
Description
Performs Chacko's test for testing against ordered alternatives.
Usage
chackoTest(x, ...)## Default S3 method:chackoTest(x, g, alternative = c("greater", "less"), ...)## S3 method for class 'formula'chackoTest(formula, data, subset, na.action, alternative = alternative, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
The null hypothesis, H_0: \theta_1 = \theta_2 = \ldots = \theta_kis tested against a simple order hypothesis,H_\mathrm{A}: \theta_1 \le \theta_2 \le \ldots \le\theta_k,~\theta_1 < \theta_k.
LetR_{ij} be the rank ofX_{ij},whereX_{ij} is jointly rankedfrom\left\{1, 2, \ldots, N \right\}, ~~ N = \sum_{i=1}^k n_i,then the test statistic is calculated as
H = \frac{1}{\sigma_R^2} \sum_{i=1}^k n_i \left(\bar{R^*}_i - \bar{R}\right),
where\bar{R^*}_i is the isotonic mean of thei-th groupand\sigma_R^2 = N \left(N + 1\right) / 12 the expected variance (without ties).H_0 is rejected, ifH > \chi^2_{v,\alpha} withv = k -1 degree of freedom. The p-values are estimatedfrom the chi-square distribution.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Source
The source code for the application of the pool adjacent violatorstheorem to calculate the isotonic meanswas taken from the file"pava.f", which is included in thepackageIso:
Rolf Turner (2015). Iso: Functions to Perform Isotonic Regression.R package version 0.0-17.https://CRAN.R-project.org/package=Iso.
The file"pava.f" is a Ratfor modification of Algorithm AS 206.1:
Bril, G., Dykstra, R., Pillers, C., Robertson, T. (1984)Statistical Algorithms: Algorithm AS 206: IsotonicRegression in Two Independent Variables,Appl Statist34, 352–357.
The Algorith AS 206 is available from StatLibhttps://lib.stat.cmu.edu/apstat/. The Royal Statistical Societyholds the copyright to these routines,but has given its permission for their distribution provided thatno fee is charged.
Note
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
The function does neither check nor correct for ties.
References
Chacko, V. J. (1963) Testing homogeneity against ordered alternatives,Ann Math Statist34, 945–956.
See Also
kruskalTest andshirleyWilliamsTestof the packagePMCMRplus,kruskal.test of the librarystats.
Examples
## Example from Sachs (1997, p. 402)x <- c(106, 114, 116, 127, 145, 110, 125, 143, 148, 151, 136, 139, 149, 160, 174)g <- gl(3,5)levels(g) <- c("A", "B", "C")## Chacko's testchackoTest(x, g)## Cuzick's testcuzickTest(x, g)## Johnson-Mehrotra testjohnsonTest(x, g)## Jonckheere-Terpstra testjonckheereTest(x, g)## Le's testleTest(x, g)## Spearman type testspearmanTest(x, g)## Murakami's BWS trend testbwsTrendTest(x, g)## Fligner-Wolfe testflignerWolfeTest(x, g)## Shan-Young-Kang testshanTest(x, g)Chen and Jan Many-to-One Comparisons Test
Description
Performs Chen and Jan nonparametric test for contrasting increasing(decreasing) dose levels of a treatment in a randomized block design.
Usage
chenJanTest(y, ...)## Default S3 method:chenJanTest( y, groups, blocks, alternative = c("greater", "less"), p.adjust.method = c("single-step", "SD1", p.adjust.methods), ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
p.adjust.method | method for adjusting p values(see |
... | further arguments to be passed to or from methods. |
Details
Chen's test is a non-parametric step-down trend test fortesting several treatment levels with a zero control. Letthere bek groups including the control and letthe zero dose level be indicated withi = 0 and the highestdose level withi = m, then the followingm = k - 1 hypotheses are tested:
\begin{array}{ll}\mathrm{H}_{m}: \theta_0 = \theta_1 = \ldots = \theta_m, & \mathrm{A}_{m} = \theta_0 \le \theta_1 \le \ldots \theta_m, \theta_0 < \theta_m \\\mathrm{H}_{m-1}: \theta_0 = \theta_1 = \ldots = \theta_{m-1}, & \mathrm{A}_{m-1} = \theta_0 \le \theta_1 \le \ldots \theta_{m-1}, \theta_0 < \theta_{m-1} \\\vdots & \vdots \\\mathrm{H}_{1}: \theta_0 = \theta_1, & \mathrm{A}_{1} = \theta_0 < \theta_1\\\end{array}
LetY_{ij1}, Y_{ij2}, \ldots, Y_{ijn_{ij}}(i = 1, 2, \dots, b, j = 0, 1, \ldots, k ~ \mathrm{and} ~ n_{ij} \geq 1) bea i.i.d. random variable of at least ordinal scale. Further,the zero dosecontrol is indicated withj = 0.
The Mann-Whittney statistic is
T_{ij} = \sum_{u=0}^{j-1} \sum_{s=1}^{n_{ij}}\sum_{r=1}^{n_{iu}} I(Y_{ijs} - Y_{iur}),\qquad i = 1, 2, \ldots, b, ~ j = 1, 2, \ldots, k,
where where the indicator function returnsI(a) = 1, ~ \mathrm{if}~ a > 0, 0.5 ~ \mathrm{if} a = 0otherwise0.
Let
N_{ij} = \sum_{s=0}^j n_{is} \qquad i = 1, 2, \ldots, b, ~ j = 1, 2, \ldots, k,
and
T_j = \sum_{i=1}^b T_{ij} \qquad j = 1, 2, \ldots, k.
The mean and variance ofT_j are
\mu(T_j) = \sum_{i=1}^b n_{ij} ~ N_{ij-1} / 2 \qquad \mathrm{and}
\sigma(T_j) = \sum_{i=1}^b n_{ij} ~ N_{ij-1} \left[ \left(N_{ij} + 1\right) - \sum_{u=1}^{g_i} \left(t_u^3 - t_u \right) / \left\{N_{ij} \left(N_{ij} - 1\right) \right\} \right]/ 2,
withg_i the number of ties in theith block andt_u the size of the tied groupu.
The test statisticT_j^* is asymptotically multivariate normaldistributed.
T_j^* = \frac{T_j - \mu(T_j)}{\sigma(T_j)}
Ifp.adjust.method = "single-step" than the p-valuesare calculated with the probability function of the multivariatenormal distribution with\Sigma = I_k. Otherwisethe standard normal distribution is used to calculatep-values and any method as availablebyp.adjust or by the step-down procedure as proposedby Chen (1999), ifp.adjust.method = "SD1" can be usedto account for\alpha-error inflation.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Chen, Y.I., Jan, S.L., 2002. Nonparametric Identification ofthe Minimum Effective Dose for Randomized Block Designs.Commun Stat-Simul Comput31, 301–312.
See Also
Examples
## Example from Chen and Jan (2002, p. 306)## MED is at dose level 2 (0.5 ppm SO2)y <- c(0.2, 6.2, 0.3, 0.3, 4.9, 1.8, 3.9, 2, 0.3, 2.5, 5.4, 2.3, 12.7,-0.2, 2.1, 6, 1.8, 3.9, 1.1, 3.8, 2.5, 1.3, -0.8, 13.1, 1.1,12.8, 18.2, 3.4, 13.5, 4.4, 6.1, 2.8, 4, 10.6, 9, 4.2, 6.7, 35,9, 12.9, 2, 7.1, 1.5, 10.6)groups <- gl(4,11, labels = c("0", "0.25", "0.5", "1.0"))blocks <- structure(rep(1:11, 4), class = "factor",levels = c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11"))summary(chenJanTest(y, groups, blocks, alternative = "greater"))summary(chenJanTest(y, groups, blocks, alternative = "greater", p.adjust = "SD1"))Chen's Many-to-One Comparisons Test
Description
Performs Chen's nonparametric test for contrasting increasing(decreasing) dose levels of a treatment.
Usage
chenTest(x, ...)## Default S3 method:chenTest( x, g, alternative = c("greater", "less"), p.adjust.method = c("SD1", p.adjust.methods), ...)## S3 method for class 'formula'chenTest( formula, data, subset, na.action, alternative = c("greater", "less"), p.adjust.method = c("SD1", p.adjust.methods), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
p.adjust.method | method for adjusting p values(see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
Chen's test is a non-parametric step-down trend test fortesting several treatment levels with a zero control.LetX_{0j} denote a variable with thej-threalization of the control group (1 \le j \le n_0)andX_{ij} thej-the realizationin thei-th treatment group (1 \le i \le k).The variables are i.i.d. of a least ordinal scale withF(x) = F(x_0) = F(x_i), ~ (1 \le i \le k).A total ofm = k hypotheses can be tested:
\begin{array}{ll}\mathrm{H}_{m}: \theta_0 = \theta_1 = \ldots = \theta_m, & \mathrm{A}_{m} = \theta_0 \le \theta_1 \le \ldots \theta_m, \theta_0 < \theta_m \\\mathrm{H}_{m-1}: \theta_0 = \theta_1 = \ldots = \theta_{m-1}, & \mathrm{A}_{m-1} = \theta_0 \le \theta_1 \le \ldots \theta_{m-1}, \theta_0 < \theta_{m-1} \\\vdots & \vdots \\\mathrm{H}_{1}: \theta_0 = \theta_1, & \mathrm{A}_{1} = \theta_0 < \theta_1\\\end{array}
The statisticsT_i are based on a Wilcoxon-type ranking:
T_i = \sum_{j=0}^{i=1} \sum_{u=1}^{n_i} \sum_{v=1}^{n_j} I(x_{iu} - x_{jv}), \qquad (1 \leq i \leq k),
where the indicator function returnsI(a) = 1, ~ \mathrm{if}~ a > 0, 0.5 ~ \mathrm{if} a = 0otherwise0.
The expectedith mean is
\mu(T_i) = n_i N_{i-1} / 2,
withN_j = \sum_{j =0}^i n_j and theith variance:
\sigma^2(T_i) = n_i N_{i-1} / 12 ~ \left\{N_i + 1 -\sum_{j=1}^g t_j \left(t_j^2 - 1 \right) /\left[N_i \left( N_i - 1 \right)\right]\right\}.
The test statisticT_i^* is asymptotically standard normal
T_i^* = \frac{T_i - \mu(T_i)} {\sqrt{\sigma^2(T_i)}}, \qquad (1 \leq i \leq k).
The p-values are calculated from the standard normal distribution.The p-values can be adjusted with any method as availablebyp.adjust or by the step-down procedure as proposedby Chen (1999), ifp.adjust.method = "SD1".
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Note
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
Chen, Y.-I., 1999, Nonparametric Identification of theMinimum Effective Dose.Biometrics55, 1236–1240.doi:10.1111/j.0006-341X.1999.01236.x
See Also
Examples
## Chen, 1999, p. 1237,## Minimum effective dose (MED)## is at 2nd dose leveldf <- data.frame(x = c(23, 22, 14,27, 23, 21,28, 37, 35,41, 37, 43,28, 21, 30,16, 19, 13),g = gl(6, 3))levels(df$g) <- 0:5ans <- chenTest(x ~ g, data = df, alternative = "greater", p.adjust.method = "SD1")summary(ans)Cochran Test
Description
Performs Cochran's test for testing an outlying (or inlying)variance.
Usage
cochranTest(x, ...)## Default S3 method:cochranTest(x, g, alternative = c("greater", "less"), ...)## S3 method for class 'formula'cochranTest( formula, data, subset, na.action, alternative = c("greater", "less"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For normally distributed data the null hypothesis,H_0: \sigma_1^2 = \sigma_2^2 = \ldots = \sigma_k^2is tested against the alternative (greater)H_{\mathrm{A}}: \sigma_p > \sigma_i ~~ (i \le k, i \ne p) withat least one inequality being strict.
The p-value is computed with the functionpcochran.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
References
Cochran, W.G. (1941) The distribution of the largest of a set of estimatedvariances as a fraction of their total.Ann. Eugen.11, 47–52.
Wilrich, P.-T. (2011) Critical values of Mandel's h and k,Grubbs and the Cochran test statistic.Adv. Stat. Anal..doi:10.1007/s10182-011-0185-y.
See Also
Examples
data(Pentosan)cochranTest(value ~ lab, data = Pentosan, subset = (material == "A"))Testing against Ordered Alternatives (Cuzick's Test)
Description
Performs Cuzick's test for testing against ordered alternatives.
Usage
cuzickTest(x, ...)## Default S3 method:cuzickTest( x, g, alternative = c("two.sided", "greater", "less"), scores = NULL, continuity = FALSE, ...)## S3 method for class 'formula'cuzickTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), scores = NULL, continuity = FALSE, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
scores | numeric vector of scores. Defaults to |
continuity | logical indicator whether a continuity correctionshall be performed. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
The null hypothesis, H_0: \theta_1 = \theta_2 = \ldots = \theta_kis tested against a simple order hypothesis,H_\mathrm{A}: \theta_1 \le \theta_2 \le \ldots \le\theta_k,~\theta_1 < \theta_k.
The p-values are estimated from the standard normal distribution.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Note
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
Cuzick, J. (1995) A Wilcoxon-type test for trend,Statistics in Medicine4, 87–90.
See Also
kruskalTest andshirleyWilliamsTestof the packagePMCMRplus,kruskal.test of the librarystats.
Examples
## Example from Sachs (1997, p. 402)x <- c(106, 114, 116, 127, 145, 110, 125, 143, 148, 151, 136, 139, 149, 160, 174)g <- gl(3,5)levels(g) <- c("A", "B", "C")## Chacko's testchackoTest(x, g)## Cuzick's testcuzickTest(x, g)## Johnson-Mehrotra testjohnsonTest(x, g)## Jonckheere-Terpstra testjonckheereTest(x, g)## Le's testleTest(x, g)## Spearman type testspearmanTest(x, g)## Murakami's BWS trend testbwsTrendTest(x, g)## Fligner-Wolfe testflignerWolfeTest(x, g)## Shan-Young-Kang testshanTest(x, g)Grubbs Double Outlier Test
Description
Performs Grubbs double outlier test.
Usage
doubleGrubbsTest(x, alternative = c("two.sided", "greater", "less"), m = 10000)Arguments
x | a numeric vector of data. |
alternative | the alternative hypothesis.Defaults to |
m | number of Monte-Carlo replicates. |
Details
LetX denote an identically and independently distributed continuousvariate with realizationsx_i ~~ (1 \le i \le k).Further, let the increasingly ordered realizationsdenotex_{(1)} \le x_{(2)} \le \ldots \le x_{(n)}. Thenthe following model for testing two maximum outliers can be proposed:
x_{(i)} = \left\{ \begin{array}{lcl} \mu + \epsilon_{(i)}, & \qquad & i = 1, \ldots, n - 2 \\ \mu + \Delta + \epsilon_{(j)} & \qquad & j = n-1, n \\ \end{array} \right.
with\epsilon \approx N(0,\sigma). The null hypothesis,H_0: \Delta = 0 is tested against the alternative,H_{\mathrm{A}}: \Delta > 0.
For testing two minimum outliers, the model can be proposedas
x_{(i)} = \left\{ \begin{array}{lcl} \mu + \Delta + \epsilon_{(j)} & \qquad & j = 1, 2 \\ \mu + \epsilon_{(i)}, & \qquad & i = 3, \ldots, n \\ \end{array} \right.
The null hypothesis is tested against the alternative,H_{\mathrm{A}}: \Delta < 0.
The p-value is computed with the functionpdgrubbs.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
References
Grubbs, F. E. (1950) Sample criteria for testing outlying observations.Ann. Math. Stat.21, 27–58.
Wilrich, P.-T. (2011) Critical values of Mandel's h and k,Grubbs and the Cochran test statistic.Adv. Stat. Anal..doi:10.1007/s10182-011-0185-y.
Examples
data(Pentosan)dat <- subset(Pentosan, subset = (material == "A"))labMeans <- tapply(dat$value, dat$lab, mean)doubleGrubbsTest(x = labMeans, alternative = "less")Multiple Comparisons of Mean Rank Sums
Description
Performs the all-pairs comparison test for different factorlevels according to Dwass, Steel, Critchlow and Fligner.
Usage
dscfAllPairsTest(x, ...)## Default S3 method:dscfAllPairsTest(x, g, ...)## S3 method for class 'formula'dscfAllPairsTest(formula, data, subset, na.action, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith non-normally distributed residuals the DSCFall-pairs comparison test can be used. A total ofm = k(k-1)/2hypotheses can be tested. The null hypothesisH_{ij}: F_i(x) = F_j(x) is tested in the two-tailed testagainst the alternativeA_{ij}: F_i(x) \ne F_j(x), ~~ i \ne j.As opposed to the all-pairs comparison procedures that dependon Kruskal ranks, the DSCF test is basically an extension ofthe U-test as re-ranking is conducted for each pairwise test.
The p-values are estimated from the studentized range distriburtion.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Douglas, C. E., Fligner, A. M. (1991) On distribution-free multiplecomparisons in the one-way analysis of variance,Communications inStatistics - Theory and Methods20, 127–139.
Dwass, M. (1960) Some k-sample rank-order tests. InContributions toProbability and Statistics, Edited by: I. Olkin,Stanford: Stanford University Press.
Steel, R. G. D. (1960) A rank sum test for comparing all pairs oftreatments,Technometrics2, 197–207
See Also
Duncan's Multiple Range Test
Description
Performs Duncan's all-pairs comparisons test for normally distributeddata with equal group variances.
Usage
duncanTest(x, ...)## Default S3 method:duncanTest(x, g, ...)## S3 method for class 'formula'duncanTest(formula, data, subset, na.action, ...)## S3 method for class 'aov'duncanTest(x, ...)Arguments
x | a numeric vector of data values, a list of numeric datavectors or a fitted model object, usually anaov fit. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith normally distributed residuals and equal variancesDuncan's multiple range test can be performed.LetX_{ij} denote a continuous random variablewith thej-the realization (1 \le j \le n_i)in thei-th group (1 \le i \le k). Furthermore, the totalsample size isN = \sum_{i=1}^k n_i. A total ofm = k(k-1)/2hypotheses can be tested: The null hypothesis isH_{ij}: \mu_i = \mu_j ~~ (i \ne j) is tested against the alternativeA_{ij}: \mu_i \ne \mu_j (two-tailed). Duncan's all-pairs teststatistics are given by
t_{(i)(j)} \frac{\bar{X}_{(i)} - \bar{X}_{(j)}} {s_{\mathrm{in}} \left(r\right)^{1/2}}, ~~ (i < j)
withs^2_{\mathrm{in}} the within-group ANOVA variance,r = k / \sum_{i=1}^k n_i and\bar{X}_{(i)} the increasinglyordered means1 \le i \le k.The null hypothesis is rejected if
\mathrm{Pr} \left\{ |t_{(i)(j)}| \ge q_{vm'\alpha'} | \mathrm{H} \right\}_{(i)(j)} = \alpha' = \min \left\{1,~ 1 - (1 - \alpha)^{(1 / (m' - 1))} \right\},
withv = N - k degree of freedom, the rangem' = 1 + |i - j| and\alpha' the Bonferroni adjustedalpha-error. The p-values are computedfrom theTukey distribution.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Duncan, D. B. (1955) Multiple range and multiple F tests,Biometrics11, 1–42.
See Also
Examples
fit <- aov(weight ~ feed, chickwts)shapiro.test(residuals(fit))bartlett.test(weight ~ feed, chickwts)anova(fit)## also works with fitted objects of class aovres <- duncanTest(fit)summary(res)summaryGroup(res)Dunnett's T3 Test
Description
Performs Dunnett's all-pairs comparison test for normally distributeddata with unequal variances.
Usage
dunnettT3Test(x, ...)## Default S3 method:dunnettT3Test(x, g, ...)## S3 method for class 'formula'dunnettT3Test(formula, data, subset, na.action, ...)## S3 method for class 'aov'dunnettT3Test(x, ...)Arguments
x | a numeric vector of data values, a list of numeric datavectors or a fitted model object, usually anaov fit. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith normally distributed residuals but unequal groups variancesthe T3 test of Dunnett can be performed.LetX_{ij} denote a continuous random variablewith thej-the realization (1 \le j \le n_i)in thei-th group (1 \le i \le k). Furthermore, the totalsample size isN = \sum_{i=1}^k n_i. A total ofm = k(k-1)/2hypotheses can be tested: The null hypothesis isH_{ij}: \mu_i = \mu_j ~~ (i \ne j) is tested against the alternativeA_{ij}: \mu_i \ne \mu_j (two-tailed). Dunnett T3 all-pairstest statistics are given by
t_{ij} \frac{\bar{X}_i - \bar{X_j}} {\left( s^2_j / n_j + s^2_i / n_i \right)^{1/2}}, ~~ (i \ne j)
withs^2_i the variance of thei-th group.The null hypothesis is rejected (two-tailed) if
\mathrm{Pr} \left\{ |t_{ij}| \ge T_{v_{ij}\rho_{ij}\alpha'/2} | \mathrm{H} \right\}_{ij} = \alpha,
with Welch's approximate solution for calculating the degree of freedom.
v_{ij} = \frac{\left( s^2_i / n_i + s^2_j / n_j \right)^2} {s^4_i / n^2_i \left(n_i - 1\right) + s^4_j / n^2_j \left(n_j - 1\right)}.
Thep-values are computed from thestudentized maximum modulus distributionthat is the equivalent of the multivariate t distributionwith\rho_{ii} = 1, ~ \rho_{ij} = 0 ~ (i \ne j).The functionpmvt is used tocalculate thep-values.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
C. W. Dunnett (1980) Pair wise multiple comparisons in the unequalvariance case,Journal of the American StatisticalAssociation75, 796–800.
See Also
Examples
fit <- aov(weight ~ feed, chickwts)shapiro.test(residuals(fit))bartlett.test(weight ~ feed, chickwts)anova(fit)## also works with fitted objects of class aovres <- dunnettT3Test(fit)summary(res)summaryGroup(res)Dunnett's Many-to-One Comparisons Test
Description
Performs Dunnett's multiple comparisons test with one control.
Usage
dunnettTest(x, ...)## Default S3 method:dunnettTest(x, g, alternative = c("two.sided", "greater", "less"), ...)## S3 method for class 'formula'dunnettTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), ...)## S3 method for class 'aov'dunnettTest(x, alternative = c("two.sided", "greater", "less"), ...)Arguments
x | a numeric vector of data values, a list of numeric datavectors or a fitted model object, usually anaov fit. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For many-to-one comparisons in an one-factorial layoutwith normally distributed residuals Dunnett's testcan be used.LetX_{0j} denote a continuous random variablewith thej-the realization of the control group(1 \le j \le n_0) andX_{ij} thej-the realizationin thei-th treatment group (1 \le i \le k).Furthermore, the total sample size isN = n_0 + \sum_{i=1}^k n_i.A total ofm = k hypotheses can be tested: The null hypothesis isH_{i}: \mu_i = \mu_0 is tested against the alternativeA_{i}: \mu_i \ne \mu_0 (two-tailed). Dunnett's teststatistics are given by
t_{i} \frac{\bar{X}_i - \bar{X_0}} {s_{\mathrm{in}} \left(1/n_0 + 1/n_i\right)^{1/2}}, ~~ (1 \le i \le k)
withs^2_{\mathrm{in}} the within-group ANOVA variance.The null hypothesis is rejected if|t_{ij}| > |T_{kv\rho\alpha}| (two-tailed),withv = N - k degree of freedom andrho the correlation:
\rho_{ij} = \sqrt{\frac{n_i n_j} {\left(n_i + n_0\right) \left(n_j+ n_0\right)}} ~~ (i \ne j).
The p-values are computed with the functionpDunnettthat is a wrapper to the the multivariate-t distribution as implemented in the functionpmvt.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Dunnett, C. W. (1955) A multiple comparison procedure for comparing severaltreatments with a control.Journal of the American Statistical Association50, 1096–1121.
OECD (ed. 2006)Current approaches in the statistical analysisof ecotoxicity data: A guidance to application - Annexes. OECD Serieson testing and assessment, No. 54.
See Also
Examples
fit <- aov(Y ~ DOSE, data = trout)shapiro.test(residuals(fit))bartlett.test(Y ~ DOSE, data = trout)## works with fitted object of class aovsummary(dunnettTest(fit, alternative = "less"))All-Pairs Comparisons Test for Balanced Incomplete Block Designs
Description
Performs Conover-Iman all-pairs comparison test for a balanced incompleteblock design (BIBD).
Usage
durbinAllPairsTest(y, ...)## Default S3 method:durbinAllPairsTest(y, groups, blocks, p.adjust.method = p.adjust.methods, ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
p.adjust.method | method for adjusting p values(see |
... | further arguments to be passed to or from methods. |
Details
For all-pairs comparisons in a balanced incomplete block designthe proposed test of Conover and Imam can be applied.A total ofm = k(k-1)/2hypotheses can be tested. The null hypothesisH_{ij}: \theta_i = \theta_j is tested in the two-tailed testagainst the alternativeA_{ij}: \theta_i \ne \theta_j, ~~ i \ne j.
The p-values are computed from the t distribution. If no p-value adjustmentis performed (p.adjust.method = "none"),than a simple protected test is recommended, i.e.the all-pairs comparisons should only be applied after a significantdurbinTest. However, any method as implemented inp.adjust.methods can be selected by the user.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Conover, W. J., Iman, R. L. (1979)On multiple-comparisonsprocedures, Tech. Rep. LA-7677-MS, Los Alamos Scientific Laboratory.
Conover, W. J. (1999)Practical nonparametric Statistics,3rd. Edition, Wiley.
See Also
Examples
## Example for an incomplete block design:## Data from Conover (1999, p. 391).y <- matrix(c(2,NA,NA,NA,3, NA, 3, 3, 3, NA, NA, NA, 3, NA, NA, 1, 2, NA, NA, NA, 1, 1, NA, 1, 1,NA, NA, NA, NA, 2, NA, 2, 1, NA, NA, NA, NA, 3, NA, 2, 1, NA, NA, NA, NA, 3, NA, 2, 2),ncol=7, nrow=7, byrow=FALSE, dimnames=list(1:7, LETTERS[1:7]))durbinAllPairsTest(y)Durbin Test
Description
Performs Durbin's tests whether k groups(or treatments) in a two-way balanced incomplete block design (BIBD)have identical effects.
Usage
durbinTest(y, ...)## Default S3 method:durbinTest(y, groups, blocks, ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
... | further arguments to be passed to or from methods. |
Details
For testing a two factorial layout of a balanced incompleteblock design whether thek groups have identical effects,the Durbin test can be performed. The null hypothesis,H_0: \theta_i = \theta_j ~ (1 \le i < j \le k),is tested against the alternative that at leastone\theta_i \ne \theta_j.
The p-values are computed from the chi-square distribution.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Note
The function does not test, whether it is a true BIBD.This function does not test for ties.
References
Conover,W. J. (1999)Practical nonparametric Statistics,3rd. Edition, Wiley.
Heckert, N. A., Filliben, J. J. (2003)NIST Handbook 148:Dataplot Reference Manual, Volume 2:Let Subcommands and Library Functions.National Institute of Standards and Technology Handbook Series, June 2003.
Examples
## Example for an incomplete block design:## Data from Conover (1999, p. 391).y <- matrix(c(2,NA,NA,NA,3, NA, 3, 3, 3, NA, NA, NA, 3, NA, NA, 1, 2, NA, NA, NA, 1, 1, NA, 1, 1,NA, NA, NA, NA, 2, NA, 2, 1, NA, NA, NA, NA, 3, NA, 2, 1, NA, NA, NA, NA, 3, NA, 2, 2), ncol=7, nrow=7, byrow=FALSE,dimnames=list(1:7, LETTERS[1:7]))durbinTest(y)Testing Several Treatments With One Control
Description
Performs Fligner-Wolfe non-parametric test forsimultaneous testing of several locations of treatment groupsagainst the location of the control group.
Usage
flignerWolfeTest(x, ...)## Default S3 method:flignerWolfeTest( x, g, alternative = c("greater", "less"), dist = c("Wilcoxon", "Normal"), ...)## S3 method for class 'formula'flignerWolfeTest( formula, data, subset, na.action, alternative = c("greater", "less"), dist = c("Wilcoxon", "Normal"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
dist | the test distribution. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For a one-factorial layout with non-normally distributed residualsthe Fligner-Wolfe test can be used.
Let there bek-1-treatment groups and one control group, thenthe null hypothesis, H_0: \theta_i - \theta_c = 0 ~ (1 \le i \le k-1)is tested against the alternative (greater),A_1: \theta_i - \theta_c > 0 ~ (1 \le i \le k-1),with at least one inequality being strict.
Letn_c denote the sample size of the control group,N^t = \sum_{i=1}^{k-1} n_i the sum of all treatmentsample sizes andN = N^t + n_c. The test statistic without takenties into account is
W = \sum_{j=1}^{k-1} \sum_{i=1}^{n_i} r_{ij} - \frac{N^t \left(N^t + 1 \right) }{2}
withr_{ij} the rank of variablex_{ij}.The null hypothesis is rejected,ifW > W_{\alpha,m,n} withm = N^t andn = n_c.
In the presence of ties, the statistic is
\hat{z} = \frac{W - n_c N^t / 2}{s_W},
where
s_W = \frac{n_c N^t}{12 N \left(N - 1 \right)} \sum_{j=1}^g t_j \left(t_j^2 - 1\right),
withg the number of tied groups andt_jthe number of tied values in thejth group. The null hypothesisis rejected, if\hat{z} > z_\alpha (as cited in EPA 2006).
Ifdist = Wilcoxon, then thep-values are estimated from theWilcoxondistribution, else theNormal distribution is used. The latter can be used,if ties are present.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Note
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
EPA (2006)Data Quality Assessment:Statistical Methods for Practitioners(Guideline No. EPA QA/G-9S), US-EPA.
Fligner, M.A., Wolfe, D.A. (1982)Distribution-free tests for comparing severaltreatments with a control.Stat Neerl36,119–127.
See Also
kruskalTest andshirleyWilliamsTestof the packagePMCMRplus,kruskal.test of the librarystats.
Examples
## Example from Sachs (1997, p. 402)x <- c(106, 114, 116, 127, 145, 110, 125, 143, 148, 151, 136, 139, 149, 160, 174)g <- gl(3,5)levels(g) <- c("A", "B", "C")## Chacko's testchackoTest(x, g)## Cuzick's testcuzickTest(x, g)## Johnson-Mehrotra testjohnsonTest(x, g)## Jonckheere-Terpstra testjonckheereTest(x, g)## Le's testleTest(x, g)## Spearman type testspearmanTest(x, g)## Murakami's BWS trend testbwsTrendTest(x, g)## Fligner-Wolfe testflignerWolfeTest(x, g)## Shan-Young-Kang testshanTest(x, g)Conover's All-Pairs Comparisons Test for Unreplicated Blocked Data
Description
Performs Conover's all-pairs comparisons tests of Friedman-type ranked data.
Usage
frdAllPairsConoverTest(y, ...)## Default S3 method:frdAllPairsConoverTest( y, groups, blocks, p.adjust.method = c("single-step", p.adjust.methods), ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
p.adjust.method | method for adjusting p values(see |
... | further arguments to be passed to or from methods. |
Details
For all-pairs comparisons in a two factorial unreplicatedcomplete block designwith non-normally distributed residuals, Conover's test can beperformed on Friedman-type ranked data.
A total ofm = k ( k -1 )/2 hypotheses can be tested.The null hypothesis, H_{ij}: \theta_i = \theta_j, is testedin the two-tailed case against the alternative,A_{ij}: \theta_i \ne \theta_j, ~~ i \ne j.
Ifp.adjust.method == "single-step" the p-values are computedfrom the studentized range distribution. Otherwise,the p-values are computed from the t-distribution usingany of the p-adjustment methods as included inp.adjust.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Conover, W. J., Iman, R. L. (1979)On multiple-comparisonsprocedures, Tech. Rep. LA-7677-MS, Los Alamos Scientific Laboratory.
Conover, W. J. (1999)Practical nonparametric Statistics,3rd. Edition, Wiley.
See Also
friedmanTest,friedman.test,frdAllPairsExactTest,frdAllPairsMillerTest,frdAllPairsNemenyiTest,frdAllPairsSiegelTest
Examples
## Sachs, 1997, p. 675 ## Six persons (block) received six different diuretics ## (A to F, treatment). ## The responses are the Na-concentration (mval) ## in the urine measured 2 hours after each treatment. ## y <- matrix(c( 3.88, 5.64, 5.76, 4.25, 5.91, 4.33, 30.58, 30.14, 16.92, 23.19, 26.74, 10.91, 25.24, 33.52, 25.45, 18.85, 20.45, 26.67, 4.44, 7.94, 4.04, 4.4, 4.23, 4.36, 29.41, 30.72, 32.92, 28.23, 23.35, 12, 38.87, 33.12, 39.15, 28.06, 38.23, 26.65),nrow=6, ncol=6, dimnames=list(1:6, LETTERS[1:6])) print(y) friedmanTest(y) ## Eisinga et al. 2017 frdAllPairsExactTest(y=y, p.adjust = "bonferroni") ## Conover's test frdAllPairsConoverTest(y=y, p.adjust = "bonferroni") ## Nemenyi's test frdAllPairsNemenyiTest(y=y) ## Miller et al. frdAllPairsMillerTest(y=y) ## Siegel-Castellan frdAllPairsSiegelTest(y=y, p.adjust = "bonferroni") ## Irrelevant of group order? x <- as.vector(y) g <- rep(colnames(y), each = length(x)/length(colnames(y))) b <- rep(rownames(y), times = length(x)/length(rownames(y))) xDF <- data.frame(x, g, b) # grouped by colnames frdAllPairsNemenyiTest(xDF$x, groups = xDF$g, blocks = xDF$b) o <- order(xDF$b) # order per block increasingly frdAllPairsNemenyiTest(xDF$x[o], groups = xDF$g[o], blocks = xDF$b[o]) o <- order(xDF$x) # order per value increasingly frdAllPairsNemenyiTest(xDF$x[o], groups = xDF$g[o], blocks = xDF$b[o]) ## formula method (only works for Nemenyi) frdAllPairsNemenyiTest(x ~ g | b, data = xDF)Exact All-Pairs Comparisons Test for Unreplicated Blocked Data
Description
Performs exact all-pairs comparisons tests of Friedman-type ranked dataaccording to Eisinga et al. (2017).
Usage
frdAllPairsExactTest(y, ...)## Default S3 method:frdAllPairsExactTest( y, groups, blocks, p.adjust.method = p.adjust.methods, ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
p.adjust.method | method for adjusting p values(see |
... | further arguments to be passed to or from methods. |
Details
For all-pairs comparisons in a two factorial unreplicatedcomplete block designwith non-normally distributed residuals, an exact test can beperformed on Friedman-type ranked data.
A total ofm = k ( k -1 )/2 hypotheses can be tested.The null hypothesis, H_{ij}: \theta_i = \theta_j, is testedin the two-tailed case against the alternative,A_{ij}: \theta_i \ne \theta_j, ~~ i \ne j.
The exactp-valuesare computed using the code of"pexactfrsd.R"that was a supplement to the publication of Eisinga et al. (2017).Additionally, any of thep-adjustment methodsas included inp.adjust can be selected, forp-valueadjustment.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Source
The functionfrdAllPairsExactTest uses the codeof the filepexactfrsd.R that was a supplement to:
R. Eisinga, T. Heskes, B. Pelzer, M. Te Grotenhuis (2017),Exact p-values for Pairwise Comparison of Friedman Rank Sums,with Application to Comparing Classifiers,BMC Bioinformatics, 18:68.
References
Eisinga, R., Heskes, T., Pelzer, B., Te Grotenhuis, M. (2017)Exact p-values for Pairwise Comparison of Friedman Rank Sums,with Application to Comparing Classifiers,BMC Bioinformatics, 18:68.
See Also
friedmanTest,friedman.test,frdAllPairsConoverTest,frdAllPairsMillerTest,frdAllPairsNemenyiTest,frdAllPairsSiegelTest
Examples
## Sachs, 1997, p. 675 ## Six persons (block) received six different diuretics ## (A to F, treatment). ## The responses are the Na-concentration (mval) ## in the urine measured 2 hours after each treatment. ## y <- matrix(c( 3.88, 5.64, 5.76, 4.25, 5.91, 4.33, 30.58, 30.14, 16.92, 23.19, 26.74, 10.91, 25.24, 33.52, 25.45, 18.85, 20.45, 26.67, 4.44, 7.94, 4.04, 4.4, 4.23, 4.36, 29.41, 30.72, 32.92, 28.23, 23.35, 12, 38.87, 33.12, 39.15, 28.06, 38.23, 26.65),nrow=6, ncol=6, dimnames=list(1:6, LETTERS[1:6])) print(y) friedmanTest(y) ## Eisinga et al. 2017 frdAllPairsExactTest(y=y, p.adjust = "bonferroni") ## Conover's test frdAllPairsConoverTest(y=y, p.adjust = "bonferroni") ## Nemenyi's test frdAllPairsNemenyiTest(y=y) ## Miller et al. frdAllPairsMillerTest(y=y) ## Siegel-Castellan frdAllPairsSiegelTest(y=y, p.adjust = "bonferroni") ## Irrelevant of group order? x <- as.vector(y) g <- rep(colnames(y), each = length(x)/length(colnames(y))) b <- rep(rownames(y), times = length(x)/length(rownames(y))) xDF <- data.frame(x, g, b) # grouped by colnames frdAllPairsNemenyiTest(xDF$x, groups = xDF$g, blocks = xDF$b) o <- order(xDF$b) # order per block increasingly frdAllPairsNemenyiTest(xDF$x[o], groups = xDF$g[o], blocks = xDF$b[o]) o <- order(xDF$x) # order per value increasingly frdAllPairsNemenyiTest(xDF$x[o], groups = xDF$g[o], blocks = xDF$b[o]) ## formula method (only works for Nemenyi) frdAllPairsNemenyiTest(x ~ g | b, data = xDF)Millers's All-Pairs Comparisons Test for Unreplicated Blocked Data
Description
Performs Miller's all-pairs comparisons tests of Friedman-type ranked data.
Usage
frdAllPairsMillerTest(y, ...)## Default S3 method:frdAllPairsMillerTest(y, groups, blocks, ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
... | further arguments to be passed to or from methods. |
Details
For all-pairs comparisons in a two factorial unreplicatedcomplete block designwith non-normally distributed residuals, Miller's test can beperformed on Friedman-type ranked data.
A total ofm = k ( k -1 )/2 hypotheses can be tested.The null hypothesis, H_{ij}: \theta_i = \theta_j, is testedin the two-tailed case against the alternative,A_{ij}: \theta_i \ne \theta_j, ~~ i \ne j.
Thep-values are computed from the chi-square distribution.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Bortz J., Lienert, G. A., Boehnke, K. (1990)VerteilungsfreieMethoden in der Biostatistik. Berlin: Springer.
Miller Jr., R. G. (1996)Simultaneous statistical inference.New York: McGraw-Hill.
Wike, E. L. (2006),Data Analysis. A Statistical Primer forPsychology Students. New Brunswick: Aldine Transaction.
See Also
friedmanTest,friedman.test,frdAllPairsExactTest,frdAllPairsConoverTest,frdAllPairsNemenyiTest,frdAllPairsSiegelTest
Examples
## Sachs, 1997, p. 675 ## Six persons (block) received six different diuretics ## (A to F, treatment). ## The responses are the Na-concentration (mval) ## in the urine measured 2 hours after each treatment. ## y <- matrix(c( 3.88, 5.64, 5.76, 4.25, 5.91, 4.33, 30.58, 30.14, 16.92, 23.19, 26.74, 10.91, 25.24, 33.52, 25.45, 18.85, 20.45, 26.67, 4.44, 7.94, 4.04, 4.4, 4.23, 4.36, 29.41, 30.72, 32.92, 28.23, 23.35, 12, 38.87, 33.12, 39.15, 28.06, 38.23, 26.65),nrow=6, ncol=6, dimnames=list(1:6, LETTERS[1:6])) print(y) friedmanTest(y) ## Eisinga et al. 2017 frdAllPairsExactTest(y=y, p.adjust = "bonferroni") ## Conover's test frdAllPairsConoverTest(y=y, p.adjust = "bonferroni") ## Nemenyi's test frdAllPairsNemenyiTest(y=y) ## Miller et al. frdAllPairsMillerTest(y=y) ## Siegel-Castellan frdAllPairsSiegelTest(y=y, p.adjust = "bonferroni") ## Irrelevant of group order? x <- as.vector(y) g <- rep(colnames(y), each = length(x)/length(colnames(y))) b <- rep(rownames(y), times = length(x)/length(rownames(y))) xDF <- data.frame(x, g, b) # grouped by colnames frdAllPairsNemenyiTest(xDF$x, groups = xDF$g, blocks = xDF$b) o <- order(xDF$b) # order per block increasingly frdAllPairsNemenyiTest(xDF$x[o], groups = xDF$g[o], blocks = xDF$b[o]) o <- order(xDF$x) # order per value increasingly frdAllPairsNemenyiTest(xDF$x[o], groups = xDF$g[o], blocks = xDF$b[o]) ## formula method (only works for Nemenyi) frdAllPairsNemenyiTest(x ~ g | b, data = xDF)Nemenyi's All-Pairs Comparisons Test for Unreplicated Blocked Data
Description
Performs Nemenyi's all-pairs comparisons tests of Friedman-type ranked data.
Usage
frdAllPairsNemenyiTest(y, ...)## Default S3 method:frdAllPairsNemenyiTest(y, groups, blocks, ...)## S3 method for class 'formula'frdAllPairsNemenyiTest(formula, data, subset, na.action, ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
... | further arguments to be passed to or from methods. |
Details
For all-pairs comparisons in a two factorial unreplicatedcomplete block designwith non-normally distributed residuals, Nemenyi's test can beperformed on Friedman-type ranked data.
A total ofm = k ( k -1 )/2 hypotheses can be tested.The null hypothesis, H_{ij}: \theta_i = \theta_j, is testedin the two-tailed case against the alternative,A_{ij}: \theta_i \ne \theta_j, ~~ i \ne j.
Thep-values are computed from the studentized range distribution.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Demsar, J. (2006) Statistical comparisons of classifiers over multipledata sets,Journal of Machine Learning Research7, 1–30.
Miller Jr., R. G. (1996)Simultaneous statistical inference.New York: McGraw-Hill.
Nemenyi, P. (1963),Distribution-free Multiple Comparisons.Ph.D. thesis, Princeton University.
Sachs, L. (1997)Angewandte Statistik. Berlin: Springer.
See Also
friedmanTest,friedman.test,frdAllPairsExactTest,frdAllPairsConoverTest,frdAllPairsMillerTest,frdAllPairsSiegelTest
Examples
## Sachs, 1997, p. 675 ## Six persons (block) received six different diuretics ## (A to F, treatment). ## The responses are the Na-concentration (mval) ## in the urine measured 2 hours after each treatment. ## y <- matrix(c( 3.88, 5.64, 5.76, 4.25, 5.91, 4.33, 30.58, 30.14, 16.92, 23.19, 26.74, 10.91, 25.24, 33.52, 25.45, 18.85, 20.45, 26.67, 4.44, 7.94, 4.04, 4.4, 4.23, 4.36, 29.41, 30.72, 32.92, 28.23, 23.35, 12, 38.87, 33.12, 39.15, 28.06, 38.23, 26.65),nrow=6, ncol=6, dimnames=list(1:6, LETTERS[1:6])) print(y) friedmanTest(y) ## Eisinga et al. 2017 frdAllPairsExactTest(y=y, p.adjust = "bonferroni") ## Conover's test frdAllPairsConoverTest(y=y, p.adjust = "bonferroni") ## Nemenyi's test frdAllPairsNemenyiTest(y=y) ## Miller et al. frdAllPairsMillerTest(y=y) ## Siegel-Castellan frdAllPairsSiegelTest(y=y, p.adjust = "bonferroni") ## Irrelevant of group order? x <- as.vector(y) g <- rep(colnames(y), each = length(x)/length(colnames(y))) b <- rep(rownames(y), times = length(x)/length(rownames(y))) xDF <- data.frame(x, g, b) # grouped by colnames frdAllPairsNemenyiTest(xDF$x, groups = xDF$g, blocks = xDF$b) o <- order(xDF$b) # order per block increasingly frdAllPairsNemenyiTest(xDF$x[o], groups = xDF$g[o], blocks = xDF$b[o]) o <- order(xDF$x) # order per value increasingly frdAllPairsNemenyiTest(xDF$x[o], groups = xDF$g[o], blocks = xDF$b[o]) ## formula method (only works for Nemenyi) frdAllPairsNemenyiTest(x ~ g | b, data = xDF)Siegel and Castellan's All-Pairs Comparisons Test forUnreplicated Blocked Data
Description
Performs Siegel and Castellan's all-pairs comparisons testsof Friedman-type ranked data.
Usage
frdAllPairsSiegelTest(y, ...)## Default S3 method:frdAllPairsSiegelTest( y, groups, blocks, p.adjust.method = p.adjust.methods, ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
p.adjust.method | method for adjusting p values(see |
... | further arguments to be passed to or from methods. |
Details
For all-pairs comparisons in a two factorial unreplicatedcomplete block designwith non-normally distributed residuals, Siegel and Castellan's test can beperformed on Friedman-type ranked data.
A total ofm = k ( k -1 )/2 hypotheses can be tested.The null hypothesis, H_{ij}: \theta_i = \theta_j, is testedin the two-tailed case against the alternative,A_{ij}: \theta_i \ne \theta_j, ~~ i \ne j.
Thep-values are computed from the standard normal distribution.Any method as implemented inp.adjust can be used forp-value adjustment.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Siegel, S., Castellan Jr., N. J. (1988)NonparametricStatistics for the Behavioral Sciences. 2nd ed. New York: McGraw-Hill.
See Also
friedmanTest,friedman.test,frdAllPairsExactTest,frdAllPairsConoverTest,frdAllPairsNemenyiTest,frdAllPairsMillerTest
Examples
## Sachs, 1997, p. 675 ## Six persons (block) received six different diuretics ## (A to F, treatment). ## The responses are the Na-concentration (mval) ## in the urine measured 2 hours after each treatment. ## y <- matrix(c( 3.88, 5.64, 5.76, 4.25, 5.91, 4.33, 30.58, 30.14, 16.92, 23.19, 26.74, 10.91, 25.24, 33.52, 25.45, 18.85, 20.45, 26.67, 4.44, 7.94, 4.04, 4.4, 4.23, 4.36, 29.41, 30.72, 32.92, 28.23, 23.35, 12, 38.87, 33.12, 39.15, 28.06, 38.23, 26.65),nrow=6, ncol=6, dimnames=list(1:6, LETTERS[1:6])) print(y) friedmanTest(y) ## Eisinga et al. 2017 frdAllPairsExactTest(y=y, p.adjust = "bonferroni") ## Conover's test frdAllPairsConoverTest(y=y, p.adjust = "bonferroni") ## Nemenyi's test frdAllPairsNemenyiTest(y=y) ## Miller et al. frdAllPairsMillerTest(y=y) ## Siegel-Castellan frdAllPairsSiegelTest(y=y, p.adjust = "bonferroni") ## Irrelevant of group order? x <- as.vector(y) g <- rep(colnames(y), each = length(x)/length(colnames(y))) b <- rep(rownames(y), times = length(x)/length(rownames(y))) xDF <- data.frame(x, g, b) # grouped by colnames frdAllPairsNemenyiTest(xDF$x, groups = xDF$g, blocks = xDF$b) o <- order(xDF$b) # order per block increasingly frdAllPairsNemenyiTest(xDF$x[o], groups = xDF$g[o], blocks = xDF$b[o]) o <- order(xDF$x) # order per value increasingly frdAllPairsNemenyiTest(xDF$x[o], groups = xDF$g[o], blocks = xDF$b[o]) ## formula method (only works for Nemenyi) frdAllPairsNemenyiTest(x ~ g | b, data = xDF)House Test
Description
Performs House nonparametric equivalent of William's testfor contrasting increasing dose levels of a treatment ina complete randomized block design.
Usage
frdHouseTest(y, ...)## Default S3 method:frdHouseTest(y, groups, blocks, alternative = c("greater", "less"), ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
... | further arguments to be passed to or from methods. |
Details
House test is a non-parametric step-down trend test for testing several treatment levelswith a zero control. Let there bek groups including the control and letthe zero dose level be indicated withi = 0 and the highestdose level withi = m, then the followingm = k - 1 hypotheses are tested:
\begin{array}{ll}\mathrm{H}_{m}: \theta_0 = \theta_1 = \ldots = \theta_m, & \mathrm{A}_{m} = \theta_0 \le \theta_1 \le \ldots \theta_m, \theta_0 < \theta_m \\\mathrm{H}_{m-1}: \theta_0 = \theta_1 = \ldots = \theta_{m-1}, & \mathrm{A}_{m-1} = \theta_0 \le \theta_1 \le \ldots \theta_{m-1}, \theta_0 < \theta_{m-1} \\\vdots & \vdots \\\mathrm{H}_{1}: \theta_0 = \theta_1, & \mathrm{A}_{1} = \theta_0 < \theta_1\\\end{array}
LetY_{ij} ~ (1 \leq i \leq n, 0 \leq j \leq k) be a i.i.d. random variableof at least ordinal scale. Further, let\bar{R}_0,~\bar{R}_1, \ldots,~\bar{R}_kbe Friedman's average ranks and set\bar{R}_0^*, \leq \ldots \leq \bar{R}_k^*to be its isotonic regression estimators under the order restriction\theta_0 \leq \ldots \leq \theta_k.
The statistics is
T_j = \left(\bar{R}_j^* - \bar{R}_0 \right)~ \left[ \left(V_j - H_j \right)\left(2 / n \right) \right]^{-1/2} \qquad (1 \leq j \leq k),
with
V_j = \left(j + 1\right) ~ \left(j + 2 \right) / 12
and
H_j = \left(t^3 - t \right) / \left(12 j n \right),
wheret is the number of tied ranks.
The criticalt'_{i,v,\alpha}-valuesas given in the tables of Williams (1972) for\alpha = 0.05 (one-sided)are looked up according to the degree of freedoms (v = \infty) and the order number of thedose level (j).
For the comparison of the first dose level(j = 1) with the control, the criticalz-value from the standard normal distribution is used (Normal).
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Chen, Y.-I., 1999. Rank-Based Tests for Dose Finding inNonmonotonic Dose–Response Settings.Biometrics55, 1258–1262.doi:10.1111/j.0006-341X.1999.01258.x
House, D.E., 1986. A Nonparametric Version of Williams’ Test forRandomized Block Design.Biometrics42, 187–190.
See Also
friedmanTest,friedman.test,frdManyOneExactTest,frdManyOneDemsarTest
Examples
## Sachs, 1997, p. 675 ## Six persons (block) received six different diuretics ## (A to F, treatment). ## The responses are the Na-concentration (mval) ## in the urine measured 2 hours after each treatment. ## Assume A is the control. y <- matrix(c( 3.88, 5.64, 5.76, 4.25, 5.91, 4.33, 30.58, 30.14, 16.92, 23.19, 26.74, 10.91, 25.24, 33.52, 25.45, 18.85, 20.45, 26.67, 4.44, 7.94, 4.04, 4.4, 4.23, 4.36, 29.41, 30.72, 32.92, 28.23, 23.35, 12, 38.87, 33.12, 39.15, 28.06, 38.23, 26.65),nrow=6, ncol=6, dimnames=list(1:6, LETTERS[1:6])) ## Global Friedman test friedmanTest(y) ## Demsar's many-one test summary(frdManyOneDemsarTest(y=y, p.adjust = "bonferroni", alternative = "greater")) ## Exact many-one test summary(frdManyOneExactTest(y=y, p.adjust = "bonferroni", alternative = "greater")) ## Nemenyi's many-one test summary(frdManyOneNemenyiTest(y=y, alternative = "greater")) ## House test frdHouseTest(y, alternative = "greater")Demsar's Many-to-One Testfor Unreplicated Blocked Data
Description
Performs Demsar's non-parametric many-to-one comparison testfor Friedman-type ranked data.
Usage
frdManyOneDemsarTest(y, ...)## Default S3 method:frdManyOneDemsarTest( y, groups, blocks, alternative = c("two.sided", "greater", "less"), p.adjust.method = p.adjust.methods, ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
p.adjust.method | method for adjusting p values(see |
... | further arguments to be passed to or from methods. |
Details
For many-to-one comparisons (pairwise comparisons with one control)in a two factorial unreplicated complete block designwith non-normally distributed residuals, Demsar's test can beperformed on Friedman-type ranked data.
Let there bek groups including the control,then the number of treatment levels ism = k - 1.A total ofm pairwise comparisons can be performed betweenthei-th treatment level and the control.H_i: \theta_0 = \theta_i is tested in the two-tailed case againstA_i: \theta_0 \ne \theta_i, ~~ (1 \le i \le m).
Thep-values are computed from the standard normal distribution.Any of thep-adjustment methods as included inp.adjustcan be used for the adjustment ofp-values.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Demsar, J. (2006) Statistical comparisons of classifiers over multipledata sets,Journal of Machine Learning Research7, 1–30.
See Also
friedmanTest,friedman.test,frdManyOneExactTest,frdManyOneNemenyiTest.
Examples
## Sachs, 1997, p. 675 ## Six persons (block) received six different diuretics ## (A to F, treatment). ## The responses are the Na-concentration (mval) ## in the urine measured 2 hours after each treatment. ## Assume A is the control. y <- matrix(c( 3.88, 5.64, 5.76, 4.25, 5.91, 4.33, 30.58, 30.14, 16.92, 23.19, 26.74, 10.91, 25.24, 33.52, 25.45, 18.85, 20.45, 26.67, 4.44, 7.94, 4.04, 4.4, 4.23, 4.36, 29.41, 30.72, 32.92, 28.23, 23.35, 12, 38.87, 33.12, 39.15, 28.06, 38.23, 26.65),nrow=6, ncol=6, dimnames=list(1:6, LETTERS[1:6])) ## Global Friedman test friedmanTest(y) ## Demsar's many-one test summary(frdManyOneDemsarTest(y=y, p.adjust = "bonferroni", alternative = "greater")) ## Exact many-one test summary(frdManyOneExactTest(y=y, p.adjust = "bonferroni", alternative = "greater")) ## Nemenyi's many-one test summary(frdManyOneNemenyiTest(y=y, alternative = "greater")) ## House test frdHouseTest(y, alternative = "greater")Exact Many-to-One Testfor Unreplicated Blocked Data
Description
Performs an exact non-parametric many-to-one comparison testfor Friedman-type ranked data according to Eisinga et al. (2017).
Usage
frdManyOneExactTest(y, ...)## Default S3 method:frdManyOneExactTest(y, groups, blocks, p.adjust.method = p.adjust.methods, ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
p.adjust.method | method for adjusting p values(see |
... | further arguments to be passed to or from methods. |
Details
For many-to-one comparisons (pairwise comparisons with one control)in a two factorial unreplicated complete block designwith non-normally distributed residuals, an exact test can beperformed on Friedman-type ranked data.
Let there bek groups including the control,then the number of treatment levels ism = k - 1.A total ofm pairwise comparisons can be performed betweenthei-th treatment level and the control.H_i: \theta_0 = \theta_i is tested in the two-tailed case againstA_i: \theta_0 \ne \theta_i, ~~ (1 \le i \le m).
The exactp-valuesare computed using the code of"pexactfrsd.R"that was a supplement to the publication of Eisinga et al. (2017).Additionally, any of thep-adjustment methodsas included inp.adjust can be selected, forp-valueadjustment.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Eisinga, R., Heskes, T., Pelzer, B., Te Grotenhuis, M. (2017)Exact p-values for Pairwise Comparison of Friedman Rank Sums,with Application to Comparing Classifiers,BMC Bioinformatics, 18:68.
See Also
friedmanTest,friedman.test,frdManyOneDemsarTest,frdManyOneNemenyiTest.
Examples
## Sachs, 1997, p. 675 ## Six persons (block) received six different diuretics ## (A to F, treatment). ## The responses are the Na-concentration (mval) ## in the urine measured 2 hours after each treatment. ## Assume A is the control. y <- matrix(c( 3.88, 5.64, 5.76, 4.25, 5.91, 4.33, 30.58, 30.14, 16.92, 23.19, 26.74, 10.91, 25.24, 33.52, 25.45, 18.85, 20.45, 26.67, 4.44, 7.94, 4.04, 4.4, 4.23, 4.36, 29.41, 30.72, 32.92, 28.23, 23.35, 12, 38.87, 33.12, 39.15, 28.06, 38.23, 26.65),nrow=6, ncol=6, dimnames=list(1:6, LETTERS[1:6])) ## Global Friedman test friedmanTest(y) ## Demsar's many-one test summary(frdManyOneDemsarTest(y=y, p.adjust = "bonferroni", alternative = "greater")) ## Exact many-one test summary(frdManyOneExactTest(y=y, p.adjust = "bonferroni", alternative = "greater")) ## Nemenyi's many-one test summary(frdManyOneNemenyiTest(y=y, alternative = "greater")) ## House test frdHouseTest(y, alternative = "greater")Nemenyi's Many-to-One Testfor Unreplicated Blocked Data
Description
Performs Nemenyi's non-parametric many-to-one comparison testfor Friedman-type ranked data.
Usage
frdManyOneNemenyiTest(y, ...)## Default S3 method:frdManyOneNemenyiTest( y, groups, blocks, alternative = c("two.sided", "greater", "less"), ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
... | further arguments to be passed to or from methods. |
Details
For many-to-one comparisons (pairwise comparisons with one control)in a two factorial unreplicated complete block designwith non-normally distributed residuals, Nemenyi's test can beperformed on Friedman-type ranked data.
Let there bek groups including the control,then the number of treatment levels ism = k - 1.A total ofm pairwise comparisons can be performed betweenthei-th treatment level and the control.H_i: \theta_0 = \theta_i is tested in the two-tailed case againstA_i: \theta_0 \ne \theta_i, ~~ (1 \le i \le m).
Thep-values are computed from the multivariate normal distribution.Aspmvnorm applies a numerical method, the estimatedp-values are seet depended.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Hollander, M., Wolfe, D. A., Chicken, E. (2014),Nonparametric Statistical Methods. 3rd ed. New York: Wiley. 2014.
Miller Jr., R. G. (1996),Simultaneous Statistical Inference.New York: McGraw-Hill.
Nemenyi, P. (1963),Distribution-free Multiple Comparisons.Ph.D. thesis, Princeton University.
Siegel, S., Castellan Jr., N. J. (1988),NonparametricStatistics for the Behavioral Sciences. 2nd ed.New York: McGraw-Hill.
Zarr, J. H. (1999),Biostatistical Analysis. 4th ed.Upper Saddle River: Prentice-Hall.
See Also
friedmanTest,friedman.test,frdManyOneExactTest,frdManyOneDemsarTestpmvnorm,set.seed
Examples
## Sachs, 1997, p. 675 ## Six persons (block) received six different diuretics ## (A to F, treatment). ## The responses are the Na-concentration (mval) ## in the urine measured 2 hours after each treatment. ## Assume A is the control. y <- matrix(c( 3.88, 5.64, 5.76, 4.25, 5.91, 4.33, 30.58, 30.14, 16.92, 23.19, 26.74, 10.91, 25.24, 33.52, 25.45, 18.85, 20.45, 26.67, 4.44, 7.94, 4.04, 4.4, 4.23, 4.36, 29.41, 30.72, 32.92, 28.23, 23.35, 12, 38.87, 33.12, 39.15, 28.06, 38.23, 26.65),nrow=6, ncol=6, dimnames=list(1:6, LETTERS[1:6])) ## Global Friedman test friedmanTest(y) ## Demsar's many-one test summary(frdManyOneDemsarTest(y=y, p.adjust = "bonferroni", alternative = "greater")) ## Exact many-one test summary(frdManyOneExactTest(y=y, p.adjust = "bonferroni", alternative = "greater")) ## Nemenyi's many-one test summary(frdManyOneNemenyiTest(y=y, alternative = "greater")) ## House test frdHouseTest(y, alternative = "greater")Friedman Rank Sum Test
Description
Performs a Friedman rank sum test. The null hypothesisH_0: \theta_i = \theta_j~~(i \ne j) is tested against thealternative H_{\mathrm{A}}: \theta_i \ne \theta_j, with at leastone inequality beeing strict.
Usage
friedmanTest(y, ...)## Default S3 method:friedmanTest(y, groups, blocks, dist = c("Chisquare", "FDist"), ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
dist | the test distribution. Defaults to |
... | further arguments to be passed to or from methods. |
Details
The function has implemented Friedman's test as well asthe extension of Conover anf Iman (1981). Friedman'stest statistic is assymptotically chi-squared distributed.Consequently, the default test distribution isdist = "Chisquare".
Ifdist = "FDist" is selected, than the approach ofConover and Imam (1981) is performed.The Friedman Test using theF-distribution leads tothe same results as doing an two-way Analysis of Variance withoutinteraction on rank transformed data.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
References
Conover, W.J., Iman, R.L. (1981) Rank Transformations as a BridgeBetween Parametric and Nonparametric Statistics.Am Stat35, 124–129.
Sachs, L. (1997)Angewandte Statistik. Berlin: Springer.
See Also
Examples
## Hollander & Wolfe (1973), p. 140ff.## Comparison of three methods ("round out", "narrow angle", and## "wide angle") for rounding first base. For each of 18 players## and the three method, the average time of two runs from a point on## the first base line 35ft from home plate to a point 15ft short of## second base is recorded.RoundingTimes <-matrix(c(5.40, 5.50, 5.55, 5.85, 5.70, 5.75, 5.20, 5.60, 5.50, 5.55, 5.50, 5.40, 5.90, 5.85, 5.70, 5.45, 5.55, 5.60, 5.40, 5.40, 5.35, 5.45, 5.50, 5.35, 5.25, 5.15, 5.00, 5.85, 5.80, 5.70, 5.25, 5.20, 5.10, 5.65, 5.55, 5.45, 5.60, 5.35, 5.45, 5.05, 5.00, 4.95, 5.50, 5.50, 5.40, 5.45, 5.55, 5.50, 5.55, 5.55, 5.35, 5.45, 5.50, 5.55, 5.50, 5.45, 5.25, 5.65, 5.60, 5.40, 5.70, 5.65, 5.55, 6.30, 6.30, 6.25), nrow = 22, byrow = TRUE, dimnames = list(1 : 22, c("Round Out", "Narrow Angle", "Wide Angle")))## Chisquare distributionfriedmanTest(RoundingTimes)## check with friedman.test from R statsfriedman.test(RoundingTimes)## F-distributionfriedmanTest(RoundingTimes, dist = "FDist")## Check with One-way repeated measure ANOVArmat <- RoundingTimesfor (i in 1:length(RoundingTimes[,1])) rmat[i,] <- rank(rmat[i,])dataf <- data.frame( y = y <- as.vector(rmat), g = g <- factor(c(col(RoundingTimes))), b = b <- factor(c(row(RoundingTimes))))summary(aov(y ~ g + Error(b), data = dataf))Games-Howell Test
Description
Performs Games-Howell all-pairs comparison test for normally distributeddata with unequal group variances.
Usage
gamesHowellTest(x, ...)## Default S3 method:gamesHowellTest(x, g, ...)## S3 method for class 'formula'gamesHowellTest(formula, data, subset, na.action, ...)## S3 method for class 'aov'gamesHowellTest(x, ...)Arguments
x | a numeric vector of data values, a list of numeric datavectors or a fitted model object, usually anaov fit. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith normally distributed residuals but unequal between-groups variancesthe Games-Howell Test can be performed. LetX_{ij} denote a continuous random variablewith thej-the realization (1 \le j \le n_i)in thei-th group (1 \le i \le k). Furthermore, the totalsample size isN = \sum_{i=1}^k n_i. A total ofm = k(k-1)/2hypotheses can be tested: The null hypothesis isH_{ij}: \mu_i = \mu_j ~~ (i \ne j) is tested against the alternativeA_{ij}: \mu_i \ne \mu_j (two-tailed). Games-Howell Test all-pairstest statistics are given by
t_{ij} \frac{\bar{X}_i - \bar{X_j}} {\left( s^2_j / n_j + s^2_i / n_i \right)^{1/2}}, ~~ (i \ne j)
withs^2_i the variance of thei-th group.The null hypothesis is rejected (two-tailed) if
\mathrm{Pr} \left\{ |t_{ij}| \sqrt{2} \ge q_{m v_{ij} \alpha} | \mathrm{H} \right\}_{ij} = \alpha,
with Welch's approximate solution for calculating the degree of freedom.
v_{ij} = \frac{\left( s^2_i / n_i + s^2_j / n_j \right)^2} {s^4_i / n^2_i \left(n_i - 1\right) + s^4_j / n^2_j \left(n_j - 1\right)}.
Thep-values are computed from theTukey distribution.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
See Also
Examples
fit <- aov(weight ~ feed, chickwts)shapiro.test(residuals(fit))bartlett.test(weight ~ feed, chickwts) # var1 = varNanova(fit)## also works with fitted objects of class aovres <- gamesHowellTest(fit)summary(res)summaryGroup(res)Generalized Extreme Studentized Deviate Many-Outlier Test
Description
Performs Rosner's generalized extreme studentized deviateprocedure to detect up-tomaxr outliers in aunivariate sample that follows an approximately normal distribution.
Usage
gesdTest(x, maxr)Arguments
x | a numeric vector of data. |
maxr | the maximum number of outliers to be tested. |
References
Rosner, B. (1983) Percentage Points for a Generalized ESDMany-Outlier Procedure,Technometrics25, 165–172.
Examples
## Taken from Rosner (1983):x <- c(-0.25,0.68,0.94,1.15,1.20,1.26,1.26,1.34,1.38,1.43,1.49,1.49,1.55,1.56,1.58,1.65,1.69,1.70,1.76,1.77,1.81,1.91,1.94,1.96,1.99,2.06,2.09,2.10,2.14,2.15,2.23,2.24,2.26,2.35,2.37,2.40,2.47,2.54,2.62,2.64,2.90,2.92,2.92,2.93,3.21,3.26,3.30,3.59,3.68,4.30,4.64,5.34,5.42,6.01)out <- gesdTest(x, 10)## print methodout## summary methodsummary(out)Gore Test
Description
Performs Gore's test. The null hypothesisH_0: \theta_i = \theta_j~~(i \ne j) is tested against thealternative H_{\mathrm{A}}: \theta_i \ne \theta_j, with at leastone inequality beeing strict.
Usage
goreTest(y, groups, blocks)Arguments
y | a numeric vector of data values. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the group for thecorresponding elements of |
Details
The function has implemented Gore's test for testingmain effects in unbalanced CRB designs,i.e. there are one ore more observations per cell.The statistic is assymptotically chi-squared distributed.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
References
Gore, A. P. (1975) Some nonparametric tests and selectionprocedures for main effects in two-way layouts.Ann. Inst. Stat. Math.27, 487–500.
See Also
friedmanTest,skillingsMackTest,durbinTest
Examples
## Crop Yield of 3 varieties on two## soil classesX <-c("130,A,Light115,A,Light123,A,Light142,A,Light117,A,Heavy125,A,Heavy139,A,Heavy108,B,Light114,B,Light124,B,Light106,B,Light91,B,Heavy111,B,Heavy110,B,Heavy155,C,Light146,C,Light151,C,Light165,C,Light97,C,Heavy108,C,Heavy")con <- textConnection(X)x <- read.table(con, header=FALSE, sep=",")close(con)colnames(x) <- c("Yield", "Variety", "SoilType")goreTest(y = x$Yield, groups = x$Variety, blocks = x$SoilType)Grubbs Outlier Test
Description
Performs Grubbs single outlier test.
Usage
grubbsTest(x, alternative = c("two.sided", "greater", "less"))Arguments
x | a numeric vector of data. |
alternative | the alternative hypothesis.Defaults to |
Details
LetX denote an identically and independently distributed continuousvariate with realizationsx_i ~~ (1 \le i \le k).Further, let the increasingly ordered realizationsdenotex_{(1)} \le x_{(2)} \le \ldots \le x_{(n)}. Thenthe following model for a single maximum outlier can be proposed:
x_{(i)} = \left\{ \begin{array}{lcl} \mu + \epsilon_{(i)}, & \qquad & i = 1, \ldots, n - 1 \\ \mu + \Delta + \epsilon_{(n)} & & \\ \end{array} \right.
with\epsilon \approx N(0,\sigma). The null hypothesis,H_0: \Delta = 0 is tested against the alternative,H_{\mathrm{A}}: \Delta > 0.
For testing a single minimum outlier, the model can be proposedas
x_{(i)} = \left\{ \begin{array}{lcl} \mu + \Delta + \epsilon_{(1)} & & \\ \mu + \epsilon_{(i)}, & \qquad & i = 2, \ldots, n \\ \end{array} \right.
The null hypothesis is tested against the alternative,H_{\mathrm{A}}: \Delta < 0.
The p-value is computed with the functionpgrubbs.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
References
Grubbs, F. E. (1950) Sample criteria for testing outlying observations.Ann. Math. Stat.21, 27–58.
Wilrich, P.-T. (2011) Critical values of Mandel's h and k,Grubbs and the Cochran test statistic.Adv. Stat. Anal..doi:10.1007/s10182-011-0185-y.
Examples
data(Pentosan)dat <- subset(Pentosan, subset = (material == "A"))labMeans <- tapply(dat$value, dat$lab, mean)grubbsTest(x = labMeans, alternative = "two.sided")Hartley's Maximum F-Ratio Test of Homogeneity ofVariances
Description
Performs Hartley's maximum F-ratio test of the null thatvariances in each of the groups (samples) are the same.
Usage
hartleyTest(x, ...)## Default S3 method:hartleyTest(x, g, ...)## S3 method for class 'formula'hartleyTest(formula, data, subset, na.action, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
Ifx is a list, its elements are taken as the samplesto be compared for homogeneity of variances. In thiscase, the elements must all be numeric data vectors,g is ignored, and one can simply usehartleyTest(x) to perform the test. If the samples are notyet contained in a list, usehartleyTest(list(x, ...)).
Otherwise,x must be a numeric data vector, andg mustbe a vector or factor object of the same length asx giving thegroup for the corresponding elements ofx.
Hartley's parametric test requires normality anda nearly balanced design. The p-value of the testis calculated with the functionpmaxFratioof the packageSuppDists.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
References
Hartley, H.O. (1950) The maximum F-ratioas a short cut test for heterogeneity of variance,Biometrika37, 308–312.
See Also
Examples
hartleyTest(count ~ spray, data = InsectSprays)Hayter-Stone Test
Description
Performs the non-parametric Hayter-Stone procedureto test against an monotonically increasing alternative.
Usage
hayterStoneTest(x, ...)## Default S3 method:hayterStoneTest( x, g, alternative = c("greater", "less"), method = c("look-up", "boot", "asympt"), nperm = 10000, ...)## S3 method for class 'formula'hayterStoneTest( formula, data, subset, na.action, alternative = c("greater", "less"), method = c("look-up", "boot", "asympt"), nperm = 10000, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
method | a character string specifying the test statistic to use.Defaults to |
nperm | number of permutations for the asymptotic permutation test.Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
LetX be an identically and idepentendly distributed variablethat wasn times observed atk increasing treatment levels.Hayter and Stone (1991) proposed a non-parametric procedureto test the null hypothesis, H:\theta_i = \theta_j ~~ (i < j \le k)against a simple order alternative, A:\theta_i < \theta_j, with at leastone inequality being strict.
The statistic for a global test is calculated as,
h = \max_{1 \le i < j \le k} \frac{2 \sqrt{6} \left(U_{ij} - n_i n_j / 2 \right)} {\sqrt{n_i n_j \left(n_i + n_j + 1 \right)}},
with the Mann-Whittney counts:
U_{ij} = \sum_{a=1}^{n_i} \sum_{b=1}^{n_j} I\left\{x_{ia} < x_{ja}\right\}.
Under the large sample approximation, the test statistich is distributedash_{k,\alpha,v}. Thus, the null hypothesis is rejected, ifh > h_{k,\alpha,v}, withv = \inftydegree of freedom.
Ifmethod = "look-up" the function will not returnp-values. Instead the critical h-valuesas given in the tables of Hayter (1990) for\alpha = 0.05 (one-sided)are looked up according to the number of groups (k) andthe degree of freedoms (v = \infty).
Ifmethod = "boot" an asymptotic permutation testis conducted and ap-value is returned.
Ifmethod = "asympt" is selected the asymptoticp-value is estimated as implemented in thefunctionpHayStonLSA of the packageNSM3.
Value
Either a list of classhtest or alist with class"osrt" that contains the followingcomponents:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated statistic(s)
- crit.value
critical values for
\alpha = 0.05.- alternative
a character string describing the alternative hypothesis.
- parameter
the parameter(s) of the test distribution.
- dist
a string that denotes the test distribution.
There are print and summary methods available.
Source
Ifmethod = "asympt" is selected, this function callsan internal probability functionpHS. The GPL-2 code forthis function was taken frompHayStonLSA of thethe packageNSM3:
Grant Schneider, Eric Chicken and Rachel Becvarik (2020) NSM3:Functions and Datasets to Accompany Hollander, Wolfe, andChicken - Nonparametric Statistical Methods, Third Edition. Rpackage version 1.15.https://CRAN.R-project.org/package=NSM3
References
Hayter, A. J.(1990) A One-Sided Studentised RangeTest for Testing Against a Simple Ordered Alternative,J Amer Stat Assoc85, 778–785.
Hayter, A.J., Stone, G. (1991)Distribution free multiple comparisons for monotonically ordered treatment effects.Austral J Statist33, 335–346.
See Also
osrtTest,hsAllPairsTest,sample,pHayStonLSA
Examples
## Example from Shirley (1977)## Reaction times of mice to stimuli to their tails.x <- c(2.4, 3, 3, 2.2, 2.2, 2.2, 2.2, 2.8, 2, 3, 2.8, 2.2, 3.8, 9.4, 8.4, 3, 3.2, 4.4, 3.2, 7.4, 9.8, 3.2, 5.8, 7.8, 2.6, 2.2, 6.2, 9.4, 7.8, 3.4, 7, 9.8, 9.4, 8.8, 8.8, 3.4, 9, 8.4, 2.4, 7.8)g <- gl(4, 10)## Shirley's test## one-sided test using look-up tableshirleyWilliamsTest(x ~ g, alternative = "greater")## Chacko's global hypothesis test for 'greater'chackoTest(x , g)## post-hoc test, default is standard normal distribution (NPT'-test)summary(chaAllPairsNashimotoTest(x, g, p.adjust.method = "none"))## same but h-distribution (NPY'-test)chaAllPairsNashimotoTest(x, g, dist = "h")## NPM-testNPMTest(x, g)## Hayter-Stone testhayterStoneTest(x, g)## all-pairs comparisonshsAllPairsTest(x, g)Hayter-Stone All-Pairs Comparison Test
Description
Performs the non-parametric Hayter-Stone all-pairs procedureto test against monotonically increasing alternatives.
Usage
hsAllPairsTest(x, ...)## Default S3 method:hsAllPairsTest( x, g, alternative = c("greater", "less"), method = c("look-up", "boot", "asympt"), nperm = 10000, ...)## S3 method for class 'formula'hsAllPairsTest( formula, data, subset, na.action, alternative = c("greater", "less"), method = c("look-up", "boot", "asympt"), nperm = 10000, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
method | a character string specifying the test statistic to use.Defaults to |
nperm | number of permutations for the asymptotic permutation test.Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
LetX be an identically and idepentendly distributed variablethat wasn times observed atk increasing treatment levels.Hayter and Stone (1991) proposed a non-parametric procedureto test the null hypothesis, H:\theta_i = \theta_j ~~ (i < j \le k)against a simple order alternative, A:\theta_i < \theta_j.
The statistic for all-pairs comparisons is calculated as,
S_{ij} = \frac{2 \sqrt{6} \left(U_{ij} - n_i n_j / 2 \right)} {\sqrt{n_i n_j \left(n_i + n_j + 1 \right)}},
with the Mann-Whittney counts:
U_{ij} = \sum_{a=1}^{n_i} \sum_{b=1}^{n_j} I\left\{x_{ia} < x_{ja}\right\}.
Under the large sample approximation, the test statisticS_{ij} is distributedash_{k,\alpha,v}. Thus, the null hypothesis is rejected,ifS_{ij} > h_{k,\alpha,v}, withv = \infty degree of freedom.
Ifmethod = "look-up" the function will not returnp-values. Instead the critical h-valuesas given in the tables of Hayter (1990) for\alpha = 0.05 (one-sided)are looked up according to the number of groups (k) andthe degree of freedoms (v = \infty).
Ifmethod = "boot" an asymetric permutation testis conducted andp-values are returned.
Ifmethod = "asympt" is selected the asymptoticp-value is estimated as implemented in thefunctionpHayStonLSA of the packageNSM3.
Value
Either a list of class"PMCMR" or alist with class"osrt" that contains the followingcomponents:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated statistic(s)
- crit.value
critical values for
\alpha = 0.05.- alternative
a character string describing the alternative hypothesis.
- parameter
the parameter(s) of the test distribution.
- dist
a string that denotes the test distribution.
There are print and summary methods available.
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Source
Ifmethod = "asympt" is selected, this function callsan internal probability functionpHS. The GPL-2 code forthis function was taken frompHayStonLSA of thethe packageNSM3:
Grant Schneider, Eric Chicken and Rachel Becvarik (2020) NSM3:Functions and Datasets to Accompany Hollander, Wolfe, andChicken - Nonparametric Statistical Methods, Third Edition. Rpackage version 1.15.https://CRAN.R-project.org/package=NSM3
References
Hayter, A. J.(1990) A One-Sided Studentised RangeTest for Testing Against a Simple Ordered Alternative,Journal of the American Statistical Association85, 778–785.
Hayter, A.J., Stone, G. (1991)Distribution free multiple comparisons for monotonically ordered treatment effects.Austral J Statist33, 335–346.
See Also
Examples
## Example from Shirley (1977)## Reaction times of mice to stimuli to their tails.x <- c(2.4, 3, 3, 2.2, 2.2, 2.2, 2.2, 2.8, 2, 3, 2.8, 2.2, 3.8, 9.4, 8.4, 3, 3.2, 4.4, 3.2, 7.4, 9.8, 3.2, 5.8, 7.8, 2.6, 2.2, 6.2, 9.4, 7.8, 3.4, 7, 9.8, 9.4, 8.8, 8.8, 3.4, 9, 8.4, 2.4, 7.8)g <- gl(4, 10)## Shirley's test## one-sided test using look-up tableshirleyWilliamsTest(x ~ g, alternative = "greater")## Chacko's global hypothesis test for 'greater'chackoTest(x , g)## post-hoc test, default is standard normal distribution (NPT'-test)summary(chaAllPairsNashimotoTest(x, g, p.adjust.method = "none"))## same but h-distribution (NPY'-test)chaAllPairsNashimotoTest(x, g, dist = "h")## NPM-testNPMTest(x, g)## Hayter-Stone testhayterStoneTest(x, g)## all-pairs comparisonshsAllPairsTest(x, g)Testing against Ordered Alternatives (Johnson-Mehrotra Test)
Description
Performs the Johnson-Mehrotra test for testing against ordered alternativesin a balanced one-factorial sampling design.
Usage
johnsonTest(x, ...)## Default S3 method:johnsonTest(x, g, alternative = c("two.sided", "greater", "less"), ...)## S3 method for class 'formula'johnsonTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
The null hypothesis, H_0: \theta_1 = \theta_2 = \ldots = \theta_kis tested against a simple order hypothesis,H_\mathrm{A}: \theta_1 \le \theta_2 \le \ldots \le\theta_k,~\theta_1 < \theta_k.
The p-values are estimated from the standard normal distribution.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Note
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
Bortz, J. (1993).Statistik für Sozialwissenschaftler (4th ed.).Berlin: Springer.
Johnson, R. A., Mehrotra, K. G. (1972) Some c-samplenonparametric tests for ordered alternatives.Journal of the Indian Statistical Association9, 8–23.
See Also
kruskalTest andshirleyWilliamsTestof the packagePMCMRplus,kruskal.test of the librarystats.
Examples
## Example from Sachs (1997, p. 402)x <- c(106, 114, 116, 127, 145, 110, 125, 143, 148, 151, 136, 139, 149, 160, 174)g <- gl(3,5)levels(g) <- c("A", "B", "C")## Chacko's testchackoTest(x, g)## Cuzick's testcuzickTest(x, g)## Johnson-Mehrotra testjohnsonTest(x, g)## Jonckheere-Terpstra testjonckheereTest(x, g)## Le's testleTest(x, g)## Spearman type testspearmanTest(x, g)## Murakami's BWS trend testbwsTrendTest(x, g)## Fligner-Wolfe testflignerWolfeTest(x, g)## Shan-Young-Kang testshanTest(x, g)Testing against Ordered Alternatives (Jonckheere-Terpstra Test)
Description
Performs the Jonckheere-Terpstra test for testing against ordered alternatives.
Usage
jonckheereTest(x, ...)## Default S3 method:jonckheereTest( x, g, alternative = c("two.sided", "greater", "less"), continuity = FALSE, ...)## S3 method for class 'formula'jonckheereTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), continuity = FALSE, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
continuity | logical indicator whether a continuity correctionshall be performed. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
The null hypothesis, H_0: \theta_1 = \theta_2 = \ldots = \theta_kis tested against a simple order hypothesis,H_\mathrm{A}: \theta_1 \le \theta_2 \le \ldots \le\theta_k,~\theta_1 < \theta_k.
The p-values are estimated from the standard normal distribution.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Source
The code for the computation of the standard deviationfor the Jonckheere-Terpstra test in the presence of ties was taken from:
Kloke, J., McKean, J. (2016)npsm: Package for Nonparametric Statistical Methods using R.R package version 0.5.https://CRAN.R-project.org/package=npsm
Note
jonckheereTest(x, g, alternative = "two.sided", continuity = TRUE) isequivalent to
cor.test(x, as.numeric(g), method = "kendall", alternative = "two.sided", continuity = TRUE)
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
Jonckheere, A. R. (1954) A distribution-free k-sample testagainst ordered alternatives.Biometrica41, 133–145.
Kloke, J., McKean, J. W. (2015)Nonparametric statistical methods using R.Boca Raton, FL: Chapman & Hall/CRC.
See Also
kruskalTest andshirleyWilliamsTestof the packagePMCMRplus,kruskal.test of the librarystats.
Examples
## Example from Sachs (1997, p. 402)x <- c(106, 114, 116, 127, 145, 110, 125, 143, 148, 151, 136, 139, 149, 160, 174)g <- gl(3,5)levels(g) <- c("A", "B", "C")## Chacko's testchackoTest(x, g)## Cuzick's testcuzickTest(x, g)## Johnson-Mehrotra testjohnsonTest(x, g)## Jonckheere-Terpstra testjonckheereTest(x, g)## Le's testleTest(x, g)## Spearman type testspearmanTest(x, g)## Murakami's BWS trend testbwsTrendTest(x, g)## Fligner-Wolfe testflignerWolfeTest(x, g)## Shan-Young-Kang testshanTest(x, g)Kruskal-Wallis Rank Sum Test
Description
Performs a Kruskal-Wallis rank sum test.
Usage
kruskalTest(x, ...)## Default S3 method:kruskalTest(x, g, dist = c("Chisquare", "KruskalWallis", "FDist"), ...)## S3 method for class 'formula'kruskalTest( formula, data, subset, na.action, dist = c("Chisquare", "KruskalWallis", "FDist"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
dist | the test distribution. Defaults's to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For one-factorial designs with non-normally distributedresiduals the Kruskal-Wallis rank sum test can be performed to testthe H_0: F_1(x) = F_2(x) = \ldots = F_k(x) againstthe H_\mathrm{A}: F_i (x) \ne F_j(x)~ (i \ne j) with at leastone strict inequality.
LetR_{ij} be the joint rank ofX_{ij},withR_{(1)(1)} = 1, \ldots, R_{(n)(n)} = N, ~~ N = \sum_{i=1}^k n_i,The test statistic is calculated as
H = \sum_{i=1}^k n_i \left(\bar{R}_i - \bar{R}\right) / \sigma_R,
with the mean rank of thei-th group
\bar{R}_i = \sum_{j = 1}^{n_{i}} R_{ij} / n_i,
the expected value
\bar{R} = \left(N +1\right) / 2
and the expected variance as
\sigma_R^2 = N \left(N + 1\right) / 12.
In case of ties the statisticH is divided by\left(1 - \sum_{i=1}^r t_i^3 - t_i \right) / \left(N^3 - N\right)
According to Conover and Imam (1981), the statisticH is relatedto theF-quantile as
F = \frac{H / \left(k - 1\right)} {\left(N - 1 - H\right) / \left(N - k\right)}
which is equivalent to a one-way ANOVA F-test using rank transformed data(see examples).
The function provides three differentdist forp-value estimation:
- Chisquare
p-values are computed from theChisquaredistribution withv = k - 1degree of freedom.- KruskalWallis
p-values are computed from thepKruskalWallisof the packageSuppDists.- FDist
p-values are computed from theFDistdistributionwithv_1 = k-1, ~ v_2 = N -kdegree of freedom.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
References
Conover, W.J., Iman, R.L. (1981) Rank Transformations as a BridgeBetween Parametric and Nonparametric Statistics.Am Stat35, 124–129.
Kruskal, W.H., Wallis, W.A. (1952) Use of Ranks in One-Criterion Variance Analysis.J Am Stat Assoc47, 583–621.
Sachs, L. (1997)Angewandte Statistik. Berlin: Springer.
See Also
kruskal.test,pKruskalWallis,Chisquare,FDist
Examples
## Hollander & Wolfe (1973), 116.## Mucociliary efficiency from the rate of removal of dust in normal## subjects, subjects with obstructive airway disease, and subjects## with asbestosis.x <- c(2.9, 3.0, 2.5, 2.6, 3.2) # normal subjectsy <- c(3.8, 2.7, 4.0, 2.4) # with obstructive airway diseasez <- c(2.8, 3.4, 3.7, 2.2, 2.0) # with asbestosisg <- factor(x = c(rep(1, length(x)), rep(2, length(y)), rep(3, length(z))), labels = c("ns", "oad", "a"))dat <- data.frame( g = g, x = c(x, y, z))## AD-TestadKSampleTest(x ~ g, data = dat)## BWS-TestbwsKSampleTest(x ~ g, data = dat)## Kruskal-Test## Using incomplete beta approximationkruskalTest(x ~ g, dat, dist="KruskalWallis")## Using chisquare distributionkruskalTest(x ~ g, dat, dist="Chisquare")## Not run: ## Check with kruskal.test from R statskruskal.test(x ~ g, dat)## End(Not run)## Using Conover's FkruskalTest(x ~ g, dat, dist="FDist")## Not run: ## Check with aov on ranksanova(aov(rank(x) ~ g, dat))## Check with oneway.testoneway.test(rank(x) ~ g, dat, var.equal = TRUE)## End(Not run)## Median Test asymptoticmedianTest(x ~ g, dat)## Median Test with simulated p-valuesset.seed(112)medianTest(x ~ g, dat, simulate.p.value = TRUE)Conover's All-Pairs Rank Comparison Test
Description
Performs Conover's non-parametric all-pairs comparison testfor Kruskal-type ranked data.
Usage
kwAllPairsConoverTest(x, ...)## Default S3 method:kwAllPairsConoverTest( x, g, p.adjust.method = c("single-step", p.adjust.methods), ...)## S3 method for class 'formula'kwAllPairsConoverTest( formula, data, subset, na.action, p.adjust.method = c("single-step", p.adjust.methods), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
p.adjust.method | method for adjusting p values(see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith non-normally distributed residuals Conover's non-parametric testcan be performed. A total ofm = k(k-1)/2hypotheses can be tested. The null hypothesisH_{ij}: \mu_i(x) = \mu_j(x) is tested in the two-tailed testagainst the alternativeA_{ij}: \mu_i(x) \ne \mu_j(x), ~~ i \ne j.
Ifp.adjust.method == "single-step" the p-values are computedfrom the studentized range distribution. Otherwise,the p-values are computed from the t-distribution usingany of the p-adjustment methods as included inp.adjust.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Conover, W. J, Iman, R. L. (1979)On multiple-comparisonsprocedures, Tech. Rep. LA-7677-MS, Los Alamos Scientific Laboratory.
See Also
Tukey,TDist,p.adjust,kruskalTest,kwAllPairsDunnTest,kwAllPairsNemenyiTest
Examples
## Data set InsectSprays## Global testkruskalTest(count ~ spray, data = InsectSprays)## Conover's all-pairs comparison test## single-step means Tukey's p-adjustmentans <- kwAllPairsConoverTest(count ~ spray, data = InsectSprays, p.adjust.method = "single-step")summary(ans)## Dunn's all-pairs comparison testans <- kwAllPairsDunnTest(count ~ spray, data = InsectSprays, p.adjust.method = "bonferroni")summary(ans)## Nemenyi's all-pairs comparison testans <- kwAllPairsNemenyiTest(count ~ spray, data = InsectSprays)summary(ans)## Brown-Mood all-pairs median testans <- medianAllPairsTest(count ~ spray, data = InsectSprays)summary(ans)Dunn's All-Pairs Rank Comparison Test
Description
Performs Dunn's non-parametric all-pairs comparison testfor Kruskal-type ranked data.
Usage
kwAllPairsDunnTest(x, ...)## Default S3 method:kwAllPairsDunnTest(x, g, p.adjust.method = p.adjust.methods, ...)## S3 method for class 'formula'kwAllPairsDunnTest( formula, data, subset, na.action, p.adjust.method = p.adjust.methods, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
p.adjust.method | method for adjusting p values(see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith non-normally distributed residuals Dunn's non-parametric testcan be performed. A total ofm = k(k-1)/2hypotheses can be tested. The null hypothesisH_{ij}: \mu_i(x) = \mu_j(x) is tested in the two-tailed testagainst the alternativeA_{ij}: \mu_i(x) \ne \mu_j(x), ~~ i \ne j.
The p-values are computed from the standard normal distribution usingany of the p-adjustment methods as included inp.adjust.Originally, Dunn (1964) proposed Bonferroni's p-adjustment method.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Dunn, O. J. (1964) Multiple comparisons using rank sums,Technometrics6, 241–252.
Siegel, S., Castellan Jr., N. J. (1988)Nonparametric Statisticsfor The Behavioral Sciences. New York: McGraw-Hill.
See Also
Normal,p.adjust,kruskalTest,kwAllPairsConoverTest,kwAllPairsNemenyiTest
Examples
## Data set InsectSprays## Global testkruskalTest(count ~ spray, data = InsectSprays)## Conover's all-pairs comparison test## single-step means Tukey's p-adjustmentans <- kwAllPairsConoverTest(count ~ spray, data = InsectSprays, p.adjust.method = "single-step")summary(ans)## Dunn's all-pairs comparison testans <- kwAllPairsDunnTest(count ~ spray, data = InsectSprays, p.adjust.method = "bonferroni")summary(ans)## Nemenyi's all-pairs comparison testans <- kwAllPairsNemenyiTest(count ~ spray, data = InsectSprays)summary(ans)## Brown-Mood all-pairs median testans <- medianAllPairsTest(count ~ spray, data = InsectSprays)summary(ans)Nemenyi's All-Pairs Rank Comparison Test
Description
Performs Nemenyi's non-parametric all-pairs comparison testfor Kruskal-type ranked data.
Usage
kwAllPairsNemenyiTest(x, ...)## Default S3 method:kwAllPairsNemenyiTest(x, g, dist = c("Tukey", "Chisquare"), ...)## S3 method for class 'formula'kwAllPairsNemenyiTest( formula, data, subset, na.action, dist = c("Tukey", "Chisquare"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
dist | the distribution for determining the p-value.Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith non-normally distributed residuals Nemenyi's non-parametric testcan be performed. A total ofm = k(k-1)/2hypotheses can be tested. The null hypothesisH_{ij}: \theta_i(x) = \theta_j(x) is tested in the two-tailed testagainst the alternativeA_{ij}: \theta_i(x) \ne \theta_j(x), ~~ i \ne j.
LetR_{ij} be the rank ofX_{ij},whereX_{ij} is jointly rankedfrom\left\{1, 2, \ldots, N \right\}, ~~ N = \sum_{i=1}^k n_i,then the test statistic under the absence of ties is calculated as
t_{ij} = \frac{\bar{R}_j - \bar{R}_i}{\sigma_R \left(1/n_i + 1/n_j\right)^{1/2}} \qquad \left(i \ne j\right),
with\bar{R}_j, \bar{R}_i the mean rank of thei-th andj-th group and the expected variance as
\sigma_R^2 = N \left(N + 1\right) / 12.
A pairwise difference is significant, if|t_{ij}|/\sqrt{2} > q_{kv},withk the number of groups andv = \inftythe degree of freedom.
Sachs(1997) has given a modified approach forNemenyi's test in the presence of ties forN > 6, k > 4provided that thekruskalTest indicates significance:In the presence of ties, the test statistic iscorrected according to\hat{t}_{ij} = t_{ij} / C, with
C = 1 - \frac{\sum_{i=1}^r t_i^3 - t_i}{N^3 - N}.
The function provides two differentdistforp-value estimation:
- Tukey
The
p-values are computed from the studentizedrange distribution (aliasTukey),\mathrm{Pr} \left\{ t_{ij} \sqrt{2} \ge q_{k\infty\alpha} | mathrm{H} \right\} = \alpha.- Chisquare
The
p-values are computed from theChisquaredistribution withv = k - 1degreeof freedom.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Nemenyi, P. (1963)Distribution-free Multiple Comparisons.Ph.D. thesis, Princeton University.
Sachs, L. (1997)Angewandte Statistik. Berlin: Springer.
Wilcoxon, F., Wilcox, R. A. (1964)Some rapid approximate statistical procedures.Pearl River: Lederle Laboratories.
See Also
Tukey,Chisquare,p.adjust,kruskalTest,kwAllPairsDunnTest,kwAllPairsConoverTest
Examples
## Data set InsectSprays## Global testkruskalTest(count ~ spray, data = InsectSprays)## Conover's all-pairs comparison test## single-step means Tukey's p-adjustmentans <- kwAllPairsConoverTest(count ~ spray, data = InsectSprays, p.adjust.method = "single-step")summary(ans)## Dunn's all-pairs comparison testans <- kwAllPairsDunnTest(count ~ spray, data = InsectSprays, p.adjust.method = "bonferroni")summary(ans)## Nemenyi's all-pairs comparison testans <- kwAllPairsNemenyiTest(count ~ spray, data = InsectSprays)summary(ans)## Brown-Mood all-pairs median testans <- medianAllPairsTest(count ~ spray, data = InsectSprays)summary(ans)Conover's Many-to-One Rank Comparison Test
Description
Performs Conover's non-parametric many-to-one comparisontest for Kruskal-type ranked data.
Usage
kwManyOneConoverTest(x, ...)## Default S3 method:kwManyOneConoverTest( x, g, alternative = c("two.sided", "greater", "less"), p.adjust.method = c("single-step", p.adjust.methods), ...)## S3 method for class 'formula'kwManyOneConoverTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), p.adjust.method = c("single-step", p.adjust.methods), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
p.adjust.method | method for adjusting p values(see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For many-to-one comparisons (pairwise comparisons with one control)in an one-factorial layout with non-normally distributedresiduals Conover's non-parametric test can be performed.Let there bek groups including the control,then the number of treatment levels ism = k - 1.Thenm pairwise comparisons can be performed betweenthei-th treatment level and the control.H_i: \theta_0 = \theta_i is tested in the two-tailed case againstA_i: \theta_0 \ne \theta_i, ~~ (1 \le i \le m).
Ifp.adjust.method == "single-step" is selected,thep-values will be computedfrom the multivariatet distribution. Otherwise,thep-values are computed from thet-distribution usingany of thep-adjustment methods as included inp.adjust.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Note
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
Conover, W. J, Iman, R. L. (1979)On multiple-comparisonsprocedures, Tech. Rep. LA-7677-MS, Los Alamos Scientific Laboratory.
See Also
pmvt,TDist,kruskalTest,kwManyOneDunnTest,kwManyOneNdwTest
Examples
## Data set PlantGrowth## Global testkruskalTest(weight ~ group, data = PlantGrowth)## Conover's many-one comparison test## single-step means p-value from multivariate t distributionans <- kwManyOneConoverTest(weight ~ group, data = PlantGrowth, p.adjust.method = "single-step")summary(ans)## Conover's many-one comparison testans <- kwManyOneConoverTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Dunn's many-one comparison testans <- kwManyOneDunnTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Nemenyi's many-one comparison testans <- kwManyOneNdwTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Many one U testans <- manyOneUTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Chen Testans <- chenTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)Dunn's Many-to-One Rank Comparison Test
Description
Performs Dunn's non-parametric many-to-one comparisontest for Kruskal-type ranked data.
Usage
kwManyOneDunnTest(x, ...)## Default S3 method:kwManyOneDunnTest( x, g, alternative = c("two.sided", "greater", "less"), p.adjust.method = c("single-step", p.adjust.methods), ...)## S3 method for class 'formula'kwManyOneDunnTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), p.adjust.method = c("single-step", p.adjust.methods), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
p.adjust.method | method for adjusting p values(see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For many-to-one comparisons (pairwise comparisons with one control)in an one-factorial layout with non-normally distributedresiduals Dunn's non-parametric test can be performed.Let there bek groups including the control,then the number of treatment levels ism = k - 1.Thenm pairwise comparisons can be performed betweenthei-th treatment level and the control.H_i: \theta_0 = \theta_i is tested in the two-tailed case againstA_i: \theta_0 \ne \theta_i, ~~ (1 \le i \le m).
Ifp.adjust.method == "single-step" is selected,thep-values will be computedfrom the multivariate normal distribution. Otherwise,thep-values are computed from the standard normal distribution usingany of thep-adjustment methods as included inp.adjust.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Note
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
Dunn, O. J. (1964) Multiple comparisons using rank sums,Technometrics6, 241–252.
Siegel, S., Castellan Jr., N. J. (1988)Nonparametric Statisticsfor The Behavioral Sciences. New York: McGraw-Hill.
See Also
pmvnorm,TDist,kruskalTest,kwManyOneConoverTest,kwManyOneNdwTest
Examples
## Data set PlantGrowth## Global testkruskalTest(weight ~ group, data = PlantGrowth)## Conover's many-one comparison test## single-step means p-value from multivariate t distributionans <- kwManyOneConoverTest(weight ~ group, data = PlantGrowth, p.adjust.method = "single-step")summary(ans)## Conover's many-one comparison testans <- kwManyOneConoverTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Dunn's many-one comparison testans <- kwManyOneDunnTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Nemenyi's many-one comparison testans <- kwManyOneNdwTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Many one U testans <- manyOneUTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Chen Testans <- chenTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)Nemenyi-Damico-Wolfe Many-to-One Rank Comparison Test
Description
Performs Nemenyi-Damico-Wolfe non-parametric many-to-one comparisontest for Kruskal-type ranked data.
Usage
kwManyOneNdwTest(x, ...)## Default S3 method:kwManyOneNdwTest( x, g, alternative = c("two.sided", "greater", "less"), p.adjust.method = c("single-step", p.adjust.methods), ...)## S3 method for class 'formula'kwManyOneNdwTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), p.adjust.method = c("single-step", p.adjust.methods), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
p.adjust.method | method for adjusting p values(see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For many-to-one comparisons (pairwise comparisons with one control)in an one-factorial layout with non-normally distributedresiduals the Nemenyi-Damico-Wolfe non-parametric test can be performed.Let there bek groups including the control,then the number of treatment levels ism = k - 1.Thenm pairwise comparisons can be performed betweenthei-th treatment level and the control.H_i: \theta_0 = \theta_i is tested in the two-tailed case againstA_i: \theta_0 \ne \theta_i, ~~ (1 \le i \le m).
Ifp.adjust.method == "single-step" is selected,thep-values will be computedfrom the multivariate normal distribution. Otherwise,thep-values are computed from the standard normal distribution usingany of thep-adjustment methods as included inp.adjust.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Note
This function is essentially the same askwManyOneDunnTest, butthere is no tie correction included. Therefore, the implementation ofDunn's test is superior, when ties are present.
References
Damico, J. A., Wolfe, D. A. (1989) Extended tables of the exact distribution ofa rank statistic for treatments versus control multiple comparisons in one-waylayout designs,Communications in Statistics - Theory and Methods18,3327–3353.
Nemenyi, P. (1963)Distribution-free Multiple Comparisons,Ph.D. thesis, Princeton University.
See Also
pmvt,TDist,kruskalTest,kwManyOneDunnTest,kwManyOneConoverTest
Examples
## Data set PlantGrowth## Global testkruskalTest(weight ~ group, data = PlantGrowth)## Conover's many-one comparison test## single-step means p-value from multivariate t distributionans <- kwManyOneConoverTest(weight ~ group, data = PlantGrowth, p.adjust.method = "single-step")summary(ans)## Conover's many-one comparison testans <- kwManyOneConoverTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Dunn's many-one comparison testans <- kwManyOneDunnTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Nemenyi's many-one comparison testans <- kwManyOneNdwTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Many one U testans <- manyOneUTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Chen Testans <- chenTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)Testing against Ordered Alternatives (Le's Test)
Description
Performs Le's test for testing against ordered alternatives.
Usage
leTest(x, ...)## Default S3 method:leTest(x, g, alternative = c("two.sided", "greater", "less"), ...)## S3 method for class 'formula'leTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
The null hypothesis, H_0: \theta_1 = \theta_2 = \ldots = \theta_kis tested against a simple order hypothesis,H_\mathrm{A}: \theta_1 \le \theta_2 \le \ldots \le\theta_k,~\theta_1 < \theta_k.
The p-values are estimated from the standard normal distribution.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Note
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
Le, C. T. (1988) A new rank test against ordered alternativesin k-sample problems,Biometrical Journal30, 87–92.
See Also
kruskalTest andshirleyWilliamsTestof the packagePMCMRplus,kruskal.test of the librarystats.
Examples
## Example from Sachs (1997, p. 402)x <- c(106, 114, 116, 127, 145, 110, 125, 143, 148, 151, 136, 139, 149, 160, 174)g <- gl(3,5)levels(g) <- c("A", "B", "C")## Chacko's testchackoTest(x, g)## Cuzick's testcuzickTest(x, g)## Johnson-Mehrotra testjohnsonTest(x, g)## Jonckheere-Terpstra testjonckheereTest(x, g)## Le's testleTest(x, g)## Spearman type testspearmanTest(x, g)## Murakami's BWS trend testbwsTrendTest(x, g)## Fligner-Wolfe testflignerWolfeTest(x, g)## Shan-Young-Kang testshanTest(x, g)Least Significant Difference Test
Description
Performs the least significant difference all-pairs comparisonstest for normally distributed data with equal group variances.
Usage
lsdTest(x, ...)## Default S3 method:lsdTest(x, g, ...)## S3 method for class 'formula'lsdTest(formula, data, subset, na.action, ...)## S3 method for class 'aov'lsdTest(x, ...)Arguments
x | a numeric vector of data values, a list of numeric datavectors or a fitted model object, usually anaov fit. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith normally distributed residuals and equal variancesthe least signifiant difference test can be performedafter a significant ANOVA F-test.LetX_{ij} denote a continuous random variablewith thej-the realization (1 \le j \le n_i)in thei-th group (1 \le i \le k). Furthermore, the totalsample size isN = \sum_{i=1}^k n_i. A total ofm = k(k-1)/2hypotheses can be tested: The null hypothesis isH_{ij}: \mu_i = \mu_j ~~ (i \ne j) is tested against the alternativeA_{ij}: \mu_i \ne \mu_j (two-tailed). Fisher's LSD all-pairs teststatistics are given by
t_{ij} \frac{\bar{X}_i - \bar{X_j}} {s_{\mathrm{in}} \left(1/n_j + 1/n_i\right)^{1/2}}, ~~ (i \ne j)
withs^2_{\mathrm{in}} the within-group ANOVA variance.The null hypothesis is rejected if|t_{ij}| > t_{v\alpha/2},withv = N - k degree of freedom. The p-values (two-tailed)are computed from theTDist distribution.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Note
As there is no p-value adjustment included, this function is equivalentto Fisher's protected LSD test, provided that the LSD test isonly applied after a significant one-way ANOVA F-test.If one is interested in other types of LSD test (i.e.with p-value adustment) see functionpairwise.t.test.
References
Sachs, L. (1997)Angewandte Statistik, New York: Springer.
See Also
Examples
fit <- aov(weight ~ feed, chickwts)shapiro.test(residuals(fit))bartlett.test(weight ~ feed, chickwts)anova(fit)## also works with fitted objects of class aovres <- lsdTest(fit)summary(res)summaryGroup(res)Mack-Wolfe Test for Umbrella Alternatives
Description
Performs Mack-Wolfe non-parametric test for umbrella alternatives.
Usage
mackWolfeTest(x, ...)## Default S3 method:mackWolfeTest(x, g, p = NULL, nperm = 1000, ...)## S3 method for class 'formula'mackWolfeTest(formula, data, subset, na.action, p = NULL, nperm = 1000, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
p | the a-priori known peak as an ordinal number of the treatmentgroup including the zero dose level, i.e. |
nperm | number of permutations for the assymptotic permutation test.Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
In dose-finding studies one may assume an increasing treatmenteffect with increasing dose level. However, the testsubject may actually succumb to toxic effects at high doses,which leads to decresing treatment effects.
The scope of the Mack-Wolfe Test is to test for umbrella alternativesfor either a known or unknown pointp (i.e. dose-level),where the peak (umbrella point) is present.
H_i: \theta_0 = \theta_i = \ldots = \theta_k is testedagainst the alternative A_i: \theta_1 \le \ldots \theta_p \ge\theta_k for somep, with at least one strict inequality.
Ifp = NULL (peak unknown), the upper-tailp-value is computedvia an asymptotic bootstrap permutation test.
If an integer value forp is given (peak known), theupper-tailp-value is computed from the standard normaldistribution (pnorm).
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Note
One may increase the number of permutations to e.g.nperm = 10000in order to get more precise p-values. However, this will be onthe expense of computational time.
References
Chen, I. Y. (1991) Notes on the Mack-Wolfe and Chen-WolfeTests for Umbrella Alternatives,Biom. J.33, 281–290.
Mack, G. A., Wolfe, D. A. (1981) K-sample rank tests forumbrella alternatives,J. Amer. Statist. Assoc.76, 175–181.
See Also
Examples
## Example from Table 6.10 of Hollander and Wolfe (1999).## Plates with Salmonella bacteria of strain TA98 were exposed to## various doses of Acid Red 114 (in mu g / ml).## The data are the numbers of visible revertant colonies on 12 plates.## Assume a peak at D333 (i.e. p = 3).x <- c(22, 23, 35, 60, 59, 54, 98, 78, 50, 60, 82, 59, 22, 44, 33, 23, 21, 25)g <- as.ordered(rep(c(0, 100, 333, 1000, 3333, 10000), each=3))plot(x ~ g)mackWolfeTest(x=x, g=g, p=3)Mandel's h Test According to E 691 ASTM
Description
The function calculates theconsistency statistics h and correspondingp-values for each group (lab) according toPractice E 691 ASTM.
Usage
mandelhTest(x, ...)## Default S3 method:mandelhTest(x, g, ...)## S3 method for class 'formula'mandelhTest(formula, data, subset, na.action, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Value
A list with class"mandel" containing the following components:
- method
a character stringindicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- p.value
the p-value for the test.
- statistic
the estimated quantiles of Mandel's statistic.
- alternative
a character string describingthe alternative hypothesis.
- grouplev
a character vector describing thelevels of the groups.
- nrofrepl
the number of replicates for each group.
References
Practice E 691 (2005)Standard Practice forConducting an Interlaboratory Study to Determine thePrecision of a Test Method, ASTM International.
See Also
Examples
data(Pentosan)mandelhTest(value ~ lab, data=Pentosan, subset=(material == "A"))Mandel's k Test According to E 691 ASTM
Description
The function calculates theconsistency statistics k and correspondingp-values for each group (lab) according to Practice E 691 ASTM.
Usage
mandelkTest(x, ...)## Default S3 method:mandelkTest(x, g, ...)## S3 method for class 'formula'mandelkTest(formula, data, subset, na.action, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Value
A list with class"mandel" containing the following components:
- method
a character stringindicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- p.value
the p-value for the test.
- statistic
the estimated quantiles of Mandel's statistic.
- alternative
a character string describingthe alternative hypothesis.
- grouplev
a character vector describing thelevels of the groups.
- nrofrepl
the number of replicates for each group.
References
Practice E 691 (2005)Standard Practice forConducting an Interlaboratory Study to Determine thePrecision of a Test Method, ASTM International.
See Also
Examples
data(Pentosan)mandelkTest(value ~ lab, data=Pentosan, subset=(material == "A"))Multiple Comparisons with One Control (U-test)
Description
Performs pairwise comparisons of multiple group levels withone control.
Usage
manyOneUTest(x, ...)## Default S3 method:manyOneUTest( x, g, alternative = c("two.sided", "greater", "less"), p.adjust.method = c("single-step", p.adjust.methods), ...)## S3 method for class 'formula'manyOneUTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), p.adjust.method = c("single-step", p.adjust.methods), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
p.adjust.method | method for adjusting p values(see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
This functions performs Wilcoxon, Mann and Whitney's U-testfor a one factorial design where each factor level is tested againstone control (m = k -1 tests). As the data are re-rankedfor each comparison, this test is only suitable forbalanced (or almost balanced) experimental designs.
For the two-tailed test andp.adjust.method = "single-step"the multivariate normal distribution is used for controllingType 1 error and to calculate p-values. Otherwise,the p-values are calculated from the standard normal distributionwith any latter p-adjustment as available byp.adjust.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Note
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
OECD (ed. 2006)Current approaches in the statistical analysisof ecotoxicity data: A guidance to application, OECD Serieson testing and assessment, No. 54.
See Also
Examples
## Data set PlantGrowth## Global testkruskalTest(weight ~ group, data = PlantGrowth)## Conover's many-one comparison test## single-step means p-value from multivariate t distributionans <- kwManyOneConoverTest(weight ~ group, data = PlantGrowth, p.adjust.method = "single-step")summary(ans)## Conover's many-one comparison testans <- kwManyOneConoverTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Dunn's many-one comparison testans <- kwManyOneDunnTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Nemenyi's many-one comparison testans <- kwManyOneNdwTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Many one U testans <- manyOneUTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)## Chen Testans <- chenTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)Brown-Mood All Pairs Median Test
Description
Performs Brown-Mood All Pairs Median Test.
Usage
medianAllPairsTest(x, ...)## Default S3 method:medianAllPairsTest(x, g, p.adjust.method = p.adjust.methods, ...)## S3 method for class 'formula'medianAllPairsTest( formula, data, subset, na.action, p.adjust.method = p.adjust.methods, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
p.adjust.method | method for adjusting p values(see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith non-normally distributed residuals Brown-Moodnon-parametric Median testcan be performed. A total ofm = k(k-1)/2hypotheses can be tested. The null hypothesisH_{ij}: \mu_i(x) = \mu_j(x) is tested in the two-tailed testagainst the alternativeA_{ij}: \mu_i(x) \ne \mu_j(x), ~~ i \ne j.
In this procedure the joined median is used for classification,but pairwise Pearson Chisquare-Tests are conducted. Any methodas given byp.adjust.methods can be usedto account for multiplicity.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Brown, G.W., Mood, A.M., 1951,On Median Tests for Linear Hypotheses,in:Proceedings of the Second Berkeley Symposium onMathematical Statistics and Probability.University of California Press, pp. 159–167.
See Also
Examples
## Data set InsectSprays## Global testkruskalTest(count ~ spray, data = InsectSprays)## Conover's all-pairs comparison test## single-step means Tukey's p-adjustmentans <- kwAllPairsConoverTest(count ~ spray, data = InsectSprays, p.adjust.method = "single-step")summary(ans)## Dunn's all-pairs comparison testans <- kwAllPairsDunnTest(count ~ spray, data = InsectSprays, p.adjust.method = "bonferroni")summary(ans)## Nemenyi's all-pairs comparison testans <- kwAllPairsNemenyiTest(count ~ spray, data = InsectSprays)summary(ans)## Brown-Mood all-pairs median testans <- medianAllPairsTest(count ~ spray, data = InsectSprays)summary(ans)Brown-Mood Median Test
Description
Performs Brown-Mood Median Test.
Usage
medianTest(x, ...)## Default S3 method:medianTest(x, g, simulate.p.value = FALSE, B = 2000, ...)## S3 method for class 'formula'medianTest( formula, data, subset, na.action, simulate.p.value = FALSE, B = 2000, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
simulate.p.value | a logical indicating whether to computep-values by Monte-Carlo simulation. |
B | an integer specifying the number of replicates usedin the Monte-Carlo test. |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
The null hypothesis, H_0: \theta_1 = \theta_2 =\ldots = \theta_kis tested against the alternative,H_\mathrm{A}: \theta_i \ne \theta_j ~~(i \ne j), with at leastone unequality beeing strict.
Value
A list with class ‘htest’. For details seechisq.test.
References
Brown, G.W., Mood, A.M., 1951,On Median Tests for Linear Hypotheses,in:Proceedings of the Second Berkeley Symposium onMathematical Statistics and Probability.University of California Press, pp. 159–167.
See Also
Examples
## Hollander & Wolfe (1973), 116.## Mucociliary efficiency from the rate of removal of dust in normal## subjects, subjects with obstructive airway disease, and subjects## with asbestosis.x <- c(2.9, 3.0, 2.5, 2.6, 3.2) # normal subjectsy <- c(3.8, 2.7, 4.0, 2.4) # with obstructive airway diseasez <- c(2.8, 3.4, 3.7, 2.2, 2.0) # with asbestosisg <- factor(x = c(rep(1, length(x)), rep(2, length(y)), rep(3, length(z))), labels = c("ns", "oad", "a"))dat <- data.frame( g = g, x = c(x, y, z))## AD-TestadKSampleTest(x ~ g, data = dat)## BWS-TestbwsKSampleTest(x ~ g, data = dat)## Kruskal-Test## Using incomplete beta approximationkruskalTest(x ~ g, dat, dist="KruskalWallis")## Using chisquare distributionkruskalTest(x ~ g, dat, dist="Chisquare")## Not run: ## Check with kruskal.test from R statskruskal.test(x ~ g, dat)## End(Not run)## Using Conover's FkruskalTest(x ~ g, dat, dist="FDist")## Not run: ## Check with aov on ranksanova(aov(rank(x) ~ g, dat))## Check with oneway.testoneway.test(rank(x) ~ g, dat, var.equal = TRUE)## End(Not run)## Median Test asymptoticmedianTest(x ~ g, dat)## Median Test with simulated p-valuesset.seed(112)medianTest(x ~ g, dat, simulate.p.value = TRUE)Madhava Rao-Raghunath Test for Testing Treatment vs. Control
Description
The function has implemented the nonparametric test ofMadhava Rao and Raghunath (2016) for testing paired two-samplesfor symmetry. The null hypothesisH: F(x,y) = F(y,x)is tested against the alternativeA: F(x,y) \ne F(y,x).
Usage
mrrTest(x, ...)## Default S3 method:mrrTest(x, y = NULL, m = NULL, ...)## S3 method for class 'formula'mrrTest(formula, data, subset, na.action, ...)Arguments
x | numeric vector of data values. Non-finite (e.g., infinite or missing) values will be omitted. |
... | further arguments to be passed to or from methods. |
y | an optional numeric vector of data values:as with x non-finite values will be omitted. |
m | numeric, optional integer number, whereas |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
LetX_i andY_i, ~ i \le n denotecontinuous variables that were observedon the sameith test item (e.g. patient)withi = 1, \ldots n. Let
U_i = X_i + Y_i \qquad V_i = X_i - Y_i
LetU_{(i)} be theith order statistic,U_{(1)} \le U_{(2)} \le \ldots U_{(n)} andk thenumber of clusters, with the condition:
n = k ~ m.
Further, let the divider denoted_0 = -\infty,d_k = \infty, and else
d_j = \frac{ U_{(jm)} + U_{(jm+1)} }{2}, ~ 1 \le j \le k -1
The two counts are
n_j^{+} = \left\{ \begin{array}{lr} 1 & \mathrm{if}~ d_{j-1} < u_i < d_j, v_i > 0 \\ 0 & \end{array} \right.
and
n_j^{-} = \left\{ \begin{array}{lr} 1 & \mathrm{if}~ d_{j-1} < u_i < d_j, v_i \le 0 \\ 0 & \end{array} \right.
The test statistic is
M = \sum_{j = 1}^k \frac{\left(n_j^{+} - n_j^{-}\right)^2} {m}
The exact p-values for5 \le n \le 30 are taken from aninternal look-up table. The exact p-values were takenfrom Table 7, Appendix B of Madhava Rao and Raghunath (2016).
Ifm = NULL the function usesn = m forall prime numbers, otherwise it tries to find an value form in such a way, that fork = n / m all variablesare integer.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Note
The function returns an error code if a value formis provided that does not lead to an integer of the ratiok = n /m.
The function also returns an error code, if a tabulatedvalue for givenn,m and calculatedMcan not be found in the look-up table.
References
Madhava Rao, K.S., Ragunath, M. (2016) A Simple Nonparametric Testfor Testing Treatment Versus Control.J Stat Adv Theory Appl16,133–162.doi:10.18642/jsata_7100121717
Examples
## Madhava Rao and Raghunath (2016), p. 151## Inulin clearance of living donors## and recipients of their kidneysx <- c(61.4, 63.3, 63.7, 80.0, 77.3, 84.0, 105.0)y <- c(70.8, 89.2, 65.8, 67.1, 87.3, 85.1, 88.1)mrrTest(x, y)## formula method## Student's Sleep DatamrrTest(extra ~ group, data = sleep)Lu-Smith All-Pairs Comparison Normal Scores Test
Description
Performs Lu-Smith all-pairs comparisonnormal scores test.
Usage
normalScoresAllPairsTest(x, ...)## Default S3 method:normalScoresAllPairsTest( x, g, p.adjust.method = c("single-step", p.adjust.methods), ...)## S3 method for class 'formula'normalScoresAllPairsTest( formula, data, subset, na.action, p.adjust.method = c("single-step", p.adjust.methods), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
p.adjust.method | method for adjusting p values (see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith non-normally distributed residuals Lu and Smith'snormal scores transformation can be used prior toan all-pairs comparison test. A total ofm = k(k-1)/2hypotheses can be tested. The null hypothesisH_{ij}: F_i(x) = F_j(x) is tested in the two-tailed testagainst the alternativeA_{ij}: F_i(x) \ne F_j(x), ~~ i \ne j.Forp.adjust.method = "single-step" theTukey's studentized range distribution is used to calculatep-values (seeTukey). Otherwise, thet-distribution is used for the calculation of p-valueswith a latter p-value adjustment asperformed byp.adjust.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Lu, H., Smith, P. (1979) Distribution of normal scores statisticfor nonparametric one-way analysis of variance.Journal of the American Statistical Association74, 715–722.
See Also
normalScoresTest,normalScoresManyOneTest,normOrder.
Lu-Smith Many-One Comparisons Normal Scores Test
Description
Performs Lu-Smith multiple comparisonnormal scores test with one control.
Usage
normalScoresManyOneTest(x, ...)## Default S3 method:normalScoresManyOneTest( x, g, alternative = c("two.sided", "greater", "less"), p.adjust.method = c("single-step", p.adjust.methods), ...)## S3 method for class 'formula'normalScoresManyOneTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), p.adjust.method = c("single-step", p.adjust.methods), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
p.adjust.method | method for adjusting p values (see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For many-to-one comparisons in an one-factorial layoutwith non-normally distributed residuals Lu and Smith'snormal scores transformation can be used prior toa many-to-one comparison test. A total ofm = k-1hypotheses can be tested. The null hypothesisH_{i}: F_0(x) = F_i(x) is tested in the two-tailed testagainst the alternativeA_{i}: F_0(x) \ne F_i(x), ~~ 1 \le i \le k-1.Forp.adjust.method = "single-step" themultivariate t distribution is used to calculatep-values (seepmvt). Otherwise, thet-distribution is used for the calculation of p-valueswith a latter p-value adjustment asperformed byp.adjust.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Note
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
Lu, H., Smith, P. (1979) Distribution of normal scores statisticfor nonparametric one-way analysis of variance.Journal of the American Statistical Association74, 715–722.
See Also
normalScoresTest,normalScoresAllPairsTest,normOrder,pmvt.
Examples
## Data set PlantGrowth## Global testnormalScoresTest(weight ~ group, data = PlantGrowth)## Lu-Smith's many-one comparison testans <- normalScoresManyOneTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)Lu-Smith Normal Scores Test
Description
Performs the Lu-Smith normal score test
Usage
normalScoresTest(x, ...)## Default S3 method:normalScoresTest(x, g, ...)## S3 method for class 'formula'normalScoresTest(formula, data, subset, na.action, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For one-factorial designs with non-normally distributedresiduals the Lu-Smith normal score test can be performed to testthe H_0: F_1(x) = F_2(x) = \ldots = F_k(x) againstthe H_\mathrm{A}: F_i (x) \ne F_j(x) ~ (i \ne j) with at leastone strict inequality. This function is basically a wrapper function topNormScore of the packageSuppDists.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
References
Lu, H., Smith, P. (1979) Distribution of normal scores statisticfor nonparametric one-way analysis of variance.Journal of the American Statistical Association74, 715–722.
See Also
vanWaerdenTest,kruskalTest,pNormScore
Examples
normalScoresTest(count ~ spray, data = InsectSprays)One-Sided Studentized Range Test
Description
Performs Hayter's one-sided studentized rangetest against an ordered alternative for normal datawith equal variances.
Usage
osrtTest(x, ...)## Default S3 method:osrtTest(x, g, alternative = c("greater", "less"), ...)## S3 method for class 'formula'osrtTest( formula, data, subset, na.action, alternative = c("greater", "less"), ...)## S3 method for class 'aov'osrtTest(x, alternative = c("greater", "less"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
Hayter's one-sided studentized range test (OSRT) can be usedfor testing several treatment levels with a zero control in a balancedone-factorial design with normally distributed variables that have acommon variance. The null hypothesis, H:\mu_i = \mu_j ~~ (i < j)is tested against a simple order alternative,A:\mu_i < \mu_j, with at least one inequality being strict.
The test statistic is calculated as,
\hat{h} = \max_{1 \le i < j \le k} \frac{ \left(\bar{x}_j - \bar{x}_i \right)} {s_{\mathrm{in}} / \sqrt{n}},
withk the number of groups,n = n_1, n_2, \ldots, n_k ands_{\mathrm{in}}^2 the within ANOVA variance. The null hypothesisis rejected, if\hat{h} > h_{k,\alpha,v}, withv = N - kdegree of freedom.
For the unbalanced case with moderate imbalance the test statistic is
\hat{h} = \max_{1 \le i < j \le k} \frac{ \left(\bar{x}_j - \bar{x}_i \right)} {s_{\mathrm{in}} \sqrt{1/n_j + 1/n_i}},
The function does not return p-values. Instead the critical h-valuesas given in the tables of Hayter (1990) for\alpha = 0.05 (one-sided)are looked up according to the number of groups (k) andthe degree of freedoms (v).Non tabulated values are linearly interpolated with the functionapprox.
Value
A list with class"osrt" that contains the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated statistic(s)
- crit.value
critical values for
\alpha = 0.05.- alternative
a character string describing the alternative hypothesis.
- parameter
the parameter(s) of the test distribution.
- dist
a string that denotes the test distribution.
There are print and summary methods available.
Note
Hayter (1990) has tabulated critical h-values for balanced designs only.For some unbalanced designs somek = 3 critical h-valuescan be found in Hayter et al. 2001. ' The function will givea warning for the unbalanced case and returns thecritical valueh_{k,\alpha,v} / \sqrt{2}.
References
Hayter, A. J.(1990) A One-Sided Studentised RangeTest for Testing Against a Simple Ordered Alternative,Journal of the American Statistical Association85, 778–785.
Hayter, A.J., Miwa, T., Liu, W. (2001)Efficient Directional Inference Methodologies for theComparisons of Three Ordered Treatment Effects.J Japan Statist Soc31, 153–174.
See Also
link{hayterStoneTest}MTest
Examples
##md <- aov(weight ~ group, PlantGrowth)anova(md)osrtTest(md)MTest(md)Page Rank Sum Test
Description
Performs Page's ordered aligned rank sum test.
Usage
pageTest(y, ...)## Default S3 method:pageTest( y, groups, blocks, alternative = c("two.sided", "greater", "less"), ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
alternative | the alternative hypothesis.Defaults to |
... | further arguments to be passed to or from methods. |
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
References
Page, E. B. (1963) Ordered hypotheses for multiple treatments: Asignificance test for linear ranks,Journal of theAmerican Statistical Association58, 216–230.
Sachs, L. (1997)Angewandte Statistik. Berlin: Springer.
See Also
Examples
## Sachs (1997), pp. 671 ff.## 9 reviewers (blocks)## assigned ranks to 4 objects (groups).data(reviewers)## See Sachs (1997) p. 677pageTest(reviewers, alternative = "greater")Plotting PMCMR Objects
Description
Plotting method for objects inheriting from class"PMCMR".
Usage
## S3 method for class 'PMCMR'plot(x, alpha = 0.05, ...)Arguments
x | an object of class |
alpha | the selected alpha-level. Defaults to 0.05. |
... | further arguments for method |
Value
A box-whisker plot for each factor level. The range of the whiskers indicatethe extremes (boxplot = x, ..., range=0). Letter symbols are depicted on top of each box.Different letters indicate significantdifferences between groups on the selected level of alpha.
See Also
Examples
## data set InsectSpraysans <- kwAllPairsNemenyiTest(count ~ spray, data = InsectSprays)plot(ans)plot(ans, col="red",main="My title", xlab="Spray", "Count")Plotting mandel Objects
Description
Plotting method for objects inheriting from class"mandel".
Usage
## S3 method for class 'mandel'plot(x, alpha = 0.005, ...)Arguments
x | an object with class |
alpha | level of significance. Defaults to |
... | further arguments, currently ignored. |
See Also
demo(Pentosan)
Examples
#### Not run: data(Pentosan)md <- mandelkTest(value ~ lab, Pentosan, subset = (material == "B"))plot(md)## End(Not run)Power Calculations for Balanced Dunnett'sMany-to-One Comparison Test
Description
Compute average per-pair power of Dunnetts's multiple comparisontest with one control.
Usage
power.dunnett.test(n, groups, delta, within.var, sig.level = 0.05)Arguments
n | Number of observations (per group) |
groups | Number of groups (including control) |
delta | true difference in means |
within.var | Within group variance |
sig.level | Significance level (Type I error probability) |
Details
The function has implemented the following Eq.to estimate average per-pair power for two-sided tests:
1 - \beta = 1 - t( T_{\alpha \rho v}, v, \mathrm{ncp}) + t(-T_{\alpha \rho v}, v, \mathrm{ncp}),
withT_{\alpha \rho v} the two-sided\alpha quantile ofthe multivariate t-distribution, withv = k (n - 1)degree of freedom,k the number of groupsand correlation matrix\rho_{ij} = 0.5 ~ (i \neq j).
The non-centrality parameter for the non-central student t-distributionis
\mathrm{ncp} = |\Delta| / \sqrt{s_{\mathrm{in}}^2 ~ 2 / n }.
Value
Object of class ‘power.htest’,a list of the arguments(including the computed one) augmented withmethod andnote elements.
Note
The results for power are seed depending.
Source
The Eqs. were taken from Lecture 5,Determining Sample Size,Statistics 514, Fall 2015, Purdue University, IN, USA.
See Also
Examples
set.seed(113)power.dunnett.test(n = 9, groups = 5, delta = 30, within.var = 333.7)## compare with t-test, bonferroni correctedpower.t.test(n = 9, delta = 30, sd = sqrt(333.7),sig.level = 0.05 / 4)## Not run: ## asymptotic Monte-Carlo power analysis set.seed(113) powerMCTests(mu = c(rep(0,4), 30), n = 9, parms = list(mean = 0, sd = sqrt(333.7)), test = "dunnettTest", alternative = "two.sided")## End(Not run)Power Calculations for Balanced Tukey'sMultiple Comparison Test
Description
Compute average per-pair power of Tukey's test formultiple comparison of means.
Usage
power.tukey.test(n, groups, delta, within.var, sig.level = 0.05)Arguments
n | number of observations (per group) |
groups | number of groups |
delta | true difference in means |
within.var | within group variance |
sig.level | significance level (Type I error probability) |
Details
The function has implemented the following Eq.to estimate average per-pair power for two-sided tests:
1 - \beta = 1 - t(q_{\alpha v k}/\sqrt{2}, v, \mathrm{ncp}) + t(-q_{\alpha v k}/\sqrt{2}, v, \mathrm{ncp}),
withq_{\alpha v k} the upper\alpha quantile ofthe studentised range distribution, withv = k (n - 1)degree of freedom andk the number of groups;andt(. ~\mathrm{ncp})the probability function of the non-central student t-distributionwith non-centrality parameter
\mathrm{ncp} = |\Delta| / \sqrt{s_{\mathrm{in}}^2 ~ 2 / n }.
Value
Object of class ‘power.htest’,a list of the arguments(including the computed one) augmented withmethod andnote elements.
Source
The Eqs. were taken from Lecture 5,Determining Sample Size,Statistics 514, Fall 2015, Purdue University, IN, USA.
See Also
Examples
power.tukey.test(n = 11, groups = 5, delta = 30, within.var = 333.7)## compare with t-test, Bonferroni-correctionpower.t.test(n = 11, delta = 30, sd = sqrt(333.7),sig.level = 0.05 / 10)## Not run: powerMCTests(mu = c(rep(0,4), 30), n = 11, parms = list(mean = 0,sd = sqrt(333.7)), test = "tukeyTest")## End(Not run)Power calculations forminimum detectable difference of the Williams' test
Description
Compute the power of a Williams' test,or determine parameters to obtain a target power.
Usage
power.williams.test(n = NULL, k, delta, sd = 1, power = NULL, ...)Arguments
n | number of observations (per group). |
k | number of treatment groups. |
delta | clinically meaningful minimal difference(between a treatment group and control). |
sd | common standard deviation. |
power | power of test (1 minus Type II error probability). |
... | further arguments, currently ignored. |
Details
Exactly one of the parametersn orpowermust be passed asNULL, and thatparameter is determined from the others.
The function has implemented the following Eq. in order toestimate power (Chow et al. 2008):
1 - \beta = 1 - \Phi \left(T_{K \alpha v} - |\Delta| / \sigma \sqrt{2/n}\right)
with|\Delta| the clinically meaningful minimal difference,T_{K \alpha v} the critical Williams' t-statisticfor\alpha = 0.05,v = \infty degree of freedomand\Phi the probability function of the standard normal function.
The required sample size (balanced design) is estimatedbased on the expression as given by the PASS manual, p. 595-2:
n = 2 \sigma^2 ~ \left(T_{K \alpha v} + z_{\beta} \right)^2 ~ / ~ \Delta^2
Value
Object of class ‘power.htest’, a list of the arguments(including thecomputed one) augmented with method and note elements.
Note
The current function calculates power forsig.level = 0.05significance level (Type I error probability) only (one-sided test).
References
Chow, S.-C., Shao, J., Wan, H., 2008,Sample Size Calculations in Clinical Research, 2nd ed,Chapman & Hall/CRC: Boca Raton, FL.
See Also
Examples
## Chow et al. 2008, p. 288 depicts 53 (rounded),## better use ceiling for roundingpower.williams.test(power = 0.8, k = 3, delta = 11, sd = 22)power.williams.test(n = 54, k = 3, delta = 11, sd = 22)## PASS manual example:## up-rounded n values are:## 116, 52, 29, 14, 8 and 5## according to PASS manual, p. 595-5D <- c(10, 15, 20, 30, 40, 50)y <- sapply(D, function(delta) { power.williams.test(power = 0.9, k = 4, delta = delta, sd = 25)$n })ceiling(y)## Not run: ## compare with power.t.test ## and bonferroni correction power.t.test(power = 0.9, delta = 50, sd = 25, sig.level = 0.05 / 4, alternative = "one.sided")## End(Not run)Power Simulation for One-Factorial All-Pairs and Many-To-One Comparison Tests
Description
Performs power simulation for one-factorial all-pairs and Many-To-One comparison tests.
Usage
powerMCTests( mu, n = 10, errfn = c("Normal", "Lognormal", "Exponential", "Chisquare", "TDist", "Cauchy", "Weibull"), parms = list(mean = 0, sd = 1), test = c("kwManyOneConoverTest", "kwManyOneDunnTest", "kwManyOneNdwTest", "vanWaerdenManyOneTest", "normalScoresManyOneTest", "dunnettTest", "tamhaneDunnettTest", "ManyOneUTest", "chenTest", "kwAllPairsNemenyiTest", "kwAllPairsDunnTest", "kwAllPairsConoverTest", "normalScoresAllPairsTest", "vanWaerdenAllPairsTest", "dscfAllPairsTest", "gamesHowellTest", "lsdTest", "scheffeTest", "tamhaneT2Test", "tukeyTest", "dunnettT3Test", "pairwise.t.test", "pairwise.wilcox.test", "adManyOneTest", "adAllPairsTest", "bwsManyOneTest", "bwsAllPairsTest", "welchManyOneTTest"), alternative = c("two.sided", "greater", "less"), p.adjust.method = c("single-step", p.adjust.methods), alpha = 0.05, FWER = TRUE, replicates = 1000)Arguments
mu | numeric vector of group means. |
n | number of replicates per group. If |
errfn | the error function. Defaults to |
parms | a list that denotes the arguments for the error function.Defaults to |
test | the multiple comparison test for which the power analysis isto be performed. Defaults to |
alternative | the alternative hypothesis. Defaults to |
p.adjust.method | method for adjusting p values (see |
alpha | the nominal level of Type I Error. |
FWER | logical, indicates whether the family-wise error should be computed.Defaults to |
replicates | the number of Monte Carlo replicates or runs. Defaults to |
Details
The linear model of a one-way ANOVA can be written as:
X_{ij} = \mu_i + \epsilon_{ij}
For each Monte Carlo run, the function simulates\epsilon_{ij} based on the given error function andthe corresponding parameters. Then the specified all-pairsor many-to-one comparison test is performed.Finally, several effect sizes (Cohen's f ans R-squared),error rates (per comparison error rate,false discovery rate and familywise error rate)and test powers (any-pair power, average per-pair powerand all-pairs power) are calculated.
Value
An object with classpowerPMCMR.
Examples
## Not run: mu <- c(0, 0, 1, 2)n <- c(5, 4, 5, 5)set.seed(100)powerMCTests(mu, n, errfn="Normal", parms=list(mean=0, sd=1), test="dunnettTest", replicates=1E4)powerMCTests(mu, n, errfn="Normal", parms=list(mean=0, sd=1), test="kwManyOneDunnTest", p.adjust.method = "bonferroni", replicates=1E4)## End(Not run)Power Simulation for One-Factorial Single Hypothesis Tests
Description
Performs power simulation for one-factorialsingle hypothesis tests.
Usage
powerOneWayTests( mu, n = 10, errfn = c("Normal", "Lognormal", "Exponential", "Chisquare", "TDist", "Cauchy", "Weibull"), parms = list(mean = 0, sd = 1), test = c("kruskalTest", "leTest", "vanWaerdenTest", "normalScoresTest", "spearmanTest", "cuzickTest", "jonckheereTest", "johnsonTest", "oneway.test", "adKSampleTest", "bwsKSampleTest", "bwsTrendTest", "mackWolfeTest", "chackoTest", "flignerWolfeTest"), alternative = c("two.sided", "greater", "less"), var.equal = TRUE, dist = NULL, alpha = 0.05, FWER = TRUE, replicates = 1000, p = NULL)Arguments
mu | numeric vector of group means. |
n | number of replicates per group. If |
errfn | the error function. Defaults to |
parms | a list that denotes the arguments for the error function.Defaults to |
test | the test for which the power analysis isto be performed. Defaults to |
alternative | the alternative hypothesis. Defaults to |
var.equal | a logical variable indicating whether to treat the variancesin the samples as equal. |
dist | the test distribution. Only relevant for |
alpha | the nominal level of Type I Error. |
FWER | logical, indicates whether the family-wise error should be computed.Defaults to |
replicates | the number of Monte Carlo replicates or runs. Defaults to |
p | the a-priori known peak as an ordinal number of the treatmentgroup including the zero dose level, i.e. |
Details
The linear model of a one-way ANOVA can be written as:
X_{ij} = \mu_i + \epsilon_{ij}
For each Monte Carlo run, the function simulates\epsilon_{ij} based on the given error function andthe corresponding parameters. Then the specified test is performed.Finally, Type I and Type II error rates are calculated.
Value
An object with classpowerOneWayPMCMR.
See Also
powerMCTests,pwr.anova.test,power.anova.test
Examples
## Not run: set.seed(12)mu <- c(0, 0, 1, 2)n <- c(5, 4, 5, 5)parms <- list(mean=0, sd=1)powerOneWayTests(mu, n, parms, test = "cuzickTest",alternative = "two.sided", replicates = 1E4)## Compare power estimation for## one-way ANOVA with balanced design## as given by functions## power.anova.test, pwr.anova.test## and powerOneWayTestgroupmeans <- c(120, 130, 140, 150)SEsq <- 500 # within-variancen <- 10k <- length(groupmeans)df <- n * k - kSSQ.E <- SEsq * dfSSQ.A <- n * var(groupmeans) * (k - 1)sd.errfn <- sqrt(SSQ.E / (n * k - 1))R2 <- c("R-squared" = SSQ.A / (SSQ.A + SSQ.E))cohensf <- sqrt(R2 / (1 - R2))names(cohensf) <- "Cohens f"## R stats power functionpower.anova.test(groups = k, between.var = var(groupmeans), within.var = SEsq, n = n)## pwr power functionpwr.anova.test(k = k, n = n, f = cohensf, sig.level=0.05)## this Monte-Carlo based estimationset.seed(200)powerOneWayTests(mu = groupmeans, n = n, parms = list(mean=0, sd=sd.errfn), test = "oneway.test", var.equal = TRUE, replicates = 5E3)## Compare with effect sizesR2cohensf## End(Not run)PMCMR Printing
Description
print.PMCMR is thePMCMR method of the genericprint function which prints its argumentand returns itinvisibly (viainvisible(x)).
Usage
## S3 method for class 'PMCMR'print(x, ...)Arguments
x | an object used to select a method. |
... | further arguments. Currently ignored. |
gesdTest Printing
Description
print.gesdTest is thegesdTest method of the genericprint function which prints its argumentand returns itinvisibly (viainvisible(x)).
Usage
## S3 method for class 'gesdTest'print(x, ...)Arguments
x | an object used to select a method. |
... | further arguments. Currently ignored. |
Mandel Printing
Description
print.mandel is themandel method of the genericprint function which prints its argumentand returns itinvisibly (viainvisible(x)).
Usage
## S3 method for class 'mandel'print(x, ...)Arguments
x | an object used to select a method. |
... | further arguments. Currently ignored. |
See Also
osrt Printing
Description
print.osrt is theosrt method of the genericprint function which prints its argumentand returns itinvisibly (viainvisible(x)).
Usage
## S3 method for class 'osrt'print(x, ...)Arguments
x | an object used to select a method. |
... | further arguments. Currently ignored. |
See Also
summary.osrt
PowerOneWayPMCMR Printing
Description
print.powerOneWayPMCMR is thepowerOneWayPMCMR method of the genericprint function which prints its argumentand returns itinvisibly (viainvisible(x)).
Usage
## S3 method for class 'powerOneWayPMCMR'print(x, ...)Arguments
x | an object used to select a method. |
... | further arguments. Currently ignored. |
PowerPMCMR Printing
Description
print.powerPMCMR is thepowerPMCMR method of the genericprint function which prints its argumentand returns itinvisibly (viainvisible(x)).
Usage
## S3 method for class 'powerPMCMR'print(x, ...)Arguments
x | an object used to select a method. |
... | further arguments. Currently ignored. |
See Also
trendPMCMR Printing
Description
print.trendPMCMR is thetrendPMCMR method of the genericprint function which prints its argumentand returns itinvisibly (viainvisible(x)).
Usage
## S3 method for class 'trendPMCMR'print(x, ...)Arguments
x | an object used to select a method. |
... | further arguments. Currently ignored. |
Dunnett Distribution
Description
Distribution function and quantile functionfor the distribution of Dunnett's many-to-onecomparisons test.
Usage
qDunnett(p, n0, n)pDunnett(q, n0, n, lower.tail = TRUE)Arguments
p | vector of probabilities. |
n0 | sample size for control group. |
n | vector of sample sizes for treatment groups. |
q | vector of quantiles. |
lower.tail | logical; if TRUE (default),probabilities are |
Details
Dunnett's distribution is a special case of themultivariate t distribution.
Let the total sample size beN = n_0 + \sum_i^m n_i, withm thenumber of treatment groups, than the quantileT_{m v \rho \alpha}is calculated withv = N - k degree of freedom andthe correlation\rho
\rho_{ij} = \sqrt{\frac{n_i n_j} {\left(n_i + n_0\right) \left(n_j+ n_0\right)}} ~~ (i \ne j).
The functions determinesm via the length of the inputvectorn.
Quantiles and p-values are computed with the functionsof the packagemvtnorm.
Value
pDunnett gives the distribution function andqDunnett gives its inverse, the quantile function.
Note
The results are seed depending.
See Also
Examples
## Table gives 2.34 for df = 6, m = 2, one-sidedset.seed(112)qval <- qDunnett(p = 0.05, n0 = 3, n = rep(3,2))round(qval, 2)set.seed(112)pDunnett(qval, n0=3, n = rep(3,2), lower.tail = FALSE)## Table gives 2.65 for df = 20, m = 4, two-sidedset.seed(112)qval <- qDunnett(p = 0.05/2, n0 = 5, n = rep(5,4))round(qval, 2)set.seed(112)2 * pDunnett(qval, n0= 5, n = rep(5,4), lower.tail= FALSE)qPCR Curve Analysis Methods
Description
The data set contains 4 classifiers (blocks), i.e.bias, linearity, precision and resolution, for 11different qPCR analysis methods. The null hypothesisis that there is no preferred ranking of the method resultsper gene for the performance parameters analyzed.The rank scores were obtained by averaging resultsacross a large set of 69 genes in a biomarker data file.
Format
A data frame with 4 observations on the following 11 variables.
- Cy0
a numeric vector
- LinRegPCR
a numeric vector
- Standard_Cq
a numeric vector
- PCR_Miner
a numeric vector
- MAK2
a numeric vector
- LRE_E100
a numeric vector
- 5PSM
a numeric vector
- DART
a numeric vector
- FPLM
a numeric vector
- LRE_Emax
a numeric vector
- FPK_PCR
a numeric vector
Source
Data were taken from Table 2 of Ruijter et al. (2013, p. 38).See also Eisinga et al. (2017, pp. 14–15).
References
Eisinga, R., Heskes, T., Pelzer, B., Te Grotenhuis, M. (2017)Exact p-values for pairwise comparison of Friedman rank sums,with application to comparing classifiers.BMC Bioinformatics, 18:68.
Ruijter, J. M. et al. (2013) Evaluation of qPCR curve analysismethods for reliable biomarker discovery: Bias, resolution,precision, and implications,Methods59, 32–46.
All-Pairs Comparisons forUnreplicated Blocked Data (Quade's All-Pairs Test)
Description
Performs Quade multiple-comparison test for unreplicatedblocked data.
Usage
quadeAllPairsTest(y, ...)## Default S3 method:quadeAllPairsTest( y, groups, blocks, dist = c("TDist", "Normal"), p.adjust.method = p.adjust.methods, ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
dist | the test distribution. Defaults to |
p.adjust.method | method for adjusting p values(see |
... | further arguments to be passed to or from methods. |
Details
For all-pairs comparisons of unreplicated blocked dataQuade's test can be applied.A total ofm = k(k-1)/2hypotheses can be tested. The null hypothesisH_{ij}: \theta_i = \theta_j is tested in the two-tailed testagainst the alternativeA_{ij}: \theta_i \ne \theta_j, ~~ i \ne j.
The function has included two methods for approximate p-value estimation:
- TDist
p-values are computed from the t distribution
- Normal
p-values are computed from the standard normal distribution
If no p-value adjustment is performed (p.adjust.method = "none"),than a simple protected test is recommended, i.e.all-pairs comparisons should only be applied after a significantquade.test. However, any method as implemented inp.adjust.methods can be selected by the user.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
W. J. Conover (1999),Practical nonparametric Statistics,3rd. Edition, Wiley.
N. A. Heckert and J. J. Filliben (2003). NIST Handbook 148:Dataplot Reference Manual, Volume 2: Let Subcommands and Library Functions.National Institute of Standards and Technology Handbook Series, June 2003.
D. Quade (1979), Using weighted rankings in the analysis of completeblocks with additive block effects.Journal of the AmericanStatistical Association, 74, 680-683.
See Also
Examples
## Sachs, 1997, p. 675## Six persons (block) received six different diuretics## (A to F, treatment).## The responses are the Na-concentration (mval)## in the urine measured 2 hours after each treatment.##y <- matrix(c(3.88, 5.64, 5.76, 4.25, 5.91, 4.33, 30.58, 30.14, 16.92,23.19, 26.74, 10.91, 25.24, 33.52, 25.45, 18.85, 20.45,26.67, 4.44, 7.94, 4.04, 4.4, 4.23, 4.36, 29.41, 30.72,32.92, 28.23, 23.35, 12, 38.87, 33.12, 39.15, 28.06, 38.23,26.65),nrow=6, ncol=6,dimnames=list(1:6, LETTERS[1:6]))print(y)## Global testquade.test(y)## All-pairs comparisonsquadeAllPairsTest(y, dist="TDist", p.adjust.method="holm")Reviewers
Description
9 reviewers (blocks) assigned ranks to 4 objects (groups).
Format
The format is a 9 x 4 Matrix with Friedman type rankings:
- rows
reviewers, 1, 2, ..., 9
- columns
groups, A, B, ..., D
Source
Sachs (1997), p. 671 ff.
References
Sachs, L. (1997)Angewandte Statistik, New York: Springer.
Examples
data(reviewers)friedmanTest(reviewers)pageTest(reviewers)frdAllPairsExactTest(reviewers, p.adjust = "bonferroni")Scheffe's Test
Description
Performs Scheffe's all-pairs comparisons test for normally distributeddata with equal group variances.
Usage
scheffeTest(x, ...)## Default S3 method:scheffeTest(x, g, ...)## S3 method for class 'formula'scheffeTest(formula, data, subset, na.action, ...)## S3 method for class 'aov'scheffeTest(x, ...)Arguments
x | a numeric vector of data values, a list of numeric datavectors or a fitted model object, usually anaov fit. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith normally distributed residuals and equal variancesScheffe's test can be performed.LetX_{ij} denote a continuous random variablewith thej-the realization (1 \le j \le n_i)in thei-th group (1 \le i \le k). Furthermore, the totalsample size isN = \sum_{i=1}^k n_i. A total ofm = k(k-1)/2hypotheses can be tested: The null hypothesis isH_{ij}: \mu_i = \mu_j ~~ (i \ne j) is tested against the alternativeA_{ij}: \mu_i \ne \mu_j (two-tailed). Scheffe's all-pairs teststatistics are given by
t_{ij} \frac{\bar{X}_i - \bar{X_j}} {s_{\mathrm{in}} \left(1/n_j + 1/n_i\right)^{1/2}}, ~~ (i \ne j)
withs^2_{\mathrm{in}} the within-group ANOVA variance.The null hypothesis is rejected ift^2_{ij} > F_{v_{1}v_{2}\alpha},withv_1 = k - 1, ~ v_2 = N - k degree of freedom. The p-valuesare computed from theFDist distribution.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Bortz, J. (1993)Statistik für Sozialwissenschaftler. 4. Aufl.,Berlin: Springer.
Sachs, L. (1997)Angewandte Statistik, New York: Springer.
Scheffe, H. (1953) A Method for Judging all Contrasts in the Analysisof Variance,Biometrika40, 87–110.
See Also
Examples
fit <- aov(weight ~ feed, chickwts)shapiro.test(residuals(fit))bartlett.test(weight ~ feed, chickwts)anova(fit)## also works with fitted objects of class aovres <- scheffeTest(fit)summary(res)summaryGroup(res)Testing against Ordered Alternatives (Shan-Young-Kang Test)
Description
Performs the Shan-Young-Kang test for testing against ordered alternatives.
Usage
shanTest(x, ...)## Default S3 method:shanTest(x, g, alternative = c("greater", "less"), ...)## S3 method for class 'formula'shanTest( formula, data, subset, na.action, alternative = c("greater", "less"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis.Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
The null hypothesis, H_0: \theta_1 = \theta_2 = \ldots = \theta_kis tested against a simple order hypothesis,H_\mathrm{A}: \theta_1 \le \theta_2 \le \ldots \le\theta_k,~\theta_1 < \theta_k.
LetR_{ij} be the rank ofX_{ij},whereX_{ij} is jointly rankedfrom\left\{1, 2, \ldots, N \right\}, ~~ N = \sum_{i=1}^k n_i,the the test statistic is
S = \sum_{i = 1}^{k-1} \sum_{j = i + 1}^k D_{ij},
with
D_{ij} = \sum_{l = 1}^{n_i} \sum_{m=1}^{n_j} \left(R_{jm} - R_{il} \right)~ \mathrm{I}\left(X_{jm} > X_{il} \right),
where
\mathrm{I}(u) = \left\{ \begin{array}{c} 1, \qquad \forall~ u > 0 \\ 0, \qquad \forall~ u \le 0 \end{array} \right..
The test statistic is asymptotically normal distributed:
z = \frac{S - \mu_{\mathrm{S}}}{\sqrt{s^2_{\mathrm{S}}}}
The p-values are estimated from the standard normal distribution.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Note
The variance estimation (see Theorem 2.1, Shan et al. 2014)can become negative for certain combinations ofN,~n_i,~k\qquad (1 \le i \le k). In these cases the function will returna warning and the returned p-value will beNaN.
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
Shan, G., Young, D., Kang, L. (2014) A New Powerful NonparametricRank Test for Ordered Alternative Problem. PLOS ONE 9, e112924.https://doi.org/10.1371/journal.pone.0112924
See Also
kruskalTest andshirleyWilliamsTestof the packagePMCMRplus,kruskal.test of the librarystats.
Examples
## Example from Sachs (1997, p. 402)x <- c(106, 114, 116, 127, 145, 110, 125, 143, 148, 151, 136, 139, 149, 160, 174)g <- gl(3,5)levels(g) <- c("A", "B", "C")## Chacko's testchackoTest(x, g)## Cuzick's testcuzickTest(x, g)## Johnson-Mehrotra testjohnsonTest(x, g)## Jonckheere-Terpstra testjonckheereTest(x, g)## Le's testleTest(x, g)## Spearman type testspearmanTest(x, g)## Murakami's BWS trend testbwsTrendTest(x, g)## Fligner-Wolfe testflignerWolfeTest(x, g)## Shan-Young-Kang testshanTest(x, g)Shirley-Williams Test
Description
Performs Shirley's nonparametric equivalent of William's testfor contrasting increasing dose levels of a treatment.
Usage
shirleyWilliamsTest(x, ...)## Default S3 method:shirleyWilliamsTest( x, g, alternative = c("two.sided", "greater", "less"), method = c("look-up", "boot"), nperm = 10000, ...)## S3 method for class 'formula'shirleyWilliamsTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), method = c("look-up", "boot"), nperm = 10000, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
method | a character string specifying the test statistic to use.Defaults to |
nperm | number of permutations for the asymptotic permutation test.Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
The Shirley-William test is a non-parametric step-down trend test for testing several treatment levelswith a zero control. Let there bek groups including the control and letthe zero dose level be indicated withi = 0 and the highestdose level withi = m, then the followingm = k - 1 hypotheses are tested:
\begin{array}{ll}\mathrm{H}_{m}: \theta_0 = \theta_1 = \ldots = \theta_m, & \mathrm{A}_{m} = \theta_0 \le \theta_1 \le \ldots \theta_m, \theta_0 < \theta_m \\\mathrm{H}_{m-1}: \theta_0 = \theta_1 = \ldots = \theta_{m-1}, & \mathrm{A}_{m-1} = \theta_0 \le \theta_1 \le \ldots \theta_{m-1}, \theta_0 < \theta_{m-1} \\\vdots & \vdots \\\mathrm{H}_{1}: \theta_0 = \theta_1, & \mathrm{A}_{1} = \theta_0 < \theta_1\\\end{array}
LetR_{ij} be the rank ofX_{ij},whereX_{ij} is jointly rankedfrom\left\{1, 2, \ldots, N \right\}, ~~ N = \sum_{i=1}^k n_i,then the test statistic is
t_{i} = \frac{\max_{1 \le u \le i} \left(\sum_{j=u}^i n_j \bar{R}_j / \sum_{j=u}^i n_j \right) - \bar{R}_0}{\sigma_{R_i} \sqrt{1/n_i + 1/n_0}},
with expected variance of
\sigma_{R_i}^2 = N_i \left(N_i + 1 \right) / 12 - T_i,
whereN_i = n_0 + n_1 + n_2 + \ldots + n_i andT_i the ties for thei-th comparison is given by
T_i = \sum_{j=1}^i \frac{t_j^3 - t_j}{12 \left(N_i - 1\right)}.
The procedure starts from the highest dose level (m) to the the lowest dose level (1) andstops at the first non-significant test. The consequent lowest effect doseis the treatment level of the previous test number. This function hasincluded the modifications as recommended by Williams (1986), i.e.the data are re-ranked for each of thei-th comparison.
Ifmethod = "look-up" is selected, the function does not return p-values.Instead the criticalt'_{i,v,\alpha}-valuesas given in the tables of Williams (1972) for\alpha = 0.05 (one-sided)are looked up according to the degree of freedoms (v = \infty) and the order number of thedose level (i) and (potentially) modified according to the given extrapolationcoefficient\beta.
Non tabulated values are linearly interpolated with the functionapprox.
For the comparison of the first dose level (i = 1) with the control, the criticalz-value from the standard normal distribution is used (Normal).
Ifmethod = "boot", the p-values are estimated through an assymptoticboot-strap method. The p-values for H_1are calculated from the t distribution with infinite degree of freedom.
Value
Either a list with class"osrt" or a list with class"PMCMR".
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated statistic(s)
- crit.value
critical values for
\alpha = 0.05.- alternative
a character string describing the alternative hypothesis.
- parameter
the parameter(s) of the test distribution.
- dist
a string that denotes the test distribution.
There are print and summary methods available.
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Note
Formethod = "look-up", only tests on the level of\alpha = 0.05can be performed for alternative hypotheses less or greater.
Formethod = "boot" only the alternative"two.sided" can be calculated.One may increase the number of permutations to e.g.nperm = 10000in order to get more precise p-values. However, this will be on the expense ofcomputational time.
References
Shirley, E., (1977) Nonparametric Equivalent of Williams Test for Contrasting IncreasingDose Levels of a Treatment,Biometrics33, 386–389.
Williams, D. A. (1986) Note on Shirley's nonparametric test for comparingseveral dose levels with a zero-dose control,Biometrics42, 183–186.
See Also
Examples
## Example from Shirley (1977)## Reaction times of mice to stimuli to their tails.x <- c(2.4, 3, 3, 2.2, 2.2, 2.2, 2.2, 2.8, 2, 3, 2.8, 2.2, 3.8, 9.4, 8.4, 3, 3.2, 4.4, 3.2, 7.4, 9.8, 3.2, 5.8, 7.8, 2.6, 2.2, 6.2, 9.4, 7.8, 3.4, 7, 9.8, 9.4, 8.8, 8.8, 3.4, 9, 8.4, 2.4, 7.8)g <- gl(4, 10)## Shirley's test## one-sided test using look-up tableshirleyWilliamsTest(x ~ g, alternative = "greater")## Chacko's global hypothesis test for 'greater'chackoTest(x , g)## post-hoc test, default is standard normal distribution (NPT'-test)summary(chaAllPairsNashimotoTest(x, g, p.adjust.method = "none"))## same but h-distribution (NPY'-test)chaAllPairsNashimotoTest(x, g, dist = "h")## NPM-testNPMTest(x, g)## Hayter-Stone testhayterStoneTest(x, g)## all-pairs comparisonshsAllPairsTest(x, g)Siegel-Tukey Rank Dispersion Test
Description
Performs Siegel-Tukey non-parametricrank dispersion test.
Usage
siegelTukeyTest(x, ...)## Default S3 method:siegelTukeyTest( x, y, alternative = c("two.sided", "greater", "less"), median.corr = FALSE, ...)## S3 method for class 'formula'siegelTukeyTest(formula, data, subset, na.action, ...)Arguments
x,y | numeric vectors of data values. |
... | further arguments to be passed to or from methods. |
alternative | a character string specifying thealternative hypothesis, must be one of |
median.corr | logical indicator, whether median correctionshould be performed prior testing. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
Letx andy denote two identically and independentlydistributed variables of at least ordinal scale.Further, let\theta, and\lambda denotelocation and scale parameter of the common, but unknown distribution.Then for the two-tailed case, the null hypothesisH:\lambda_x / \lambda_y = 1 | \theta_x = \theta_y istested against the alternative,A:\lambda_x / \lambda_y \ne 1.
The data are combinedly ranked according to Siegel-Tukey.The ranking is done by alternate extremes (rank 1 is lowest,2 and 3 are the two highest, 4 and 5 are the two next lowest, etc.).If no ties are present, the p-values are computed fromthe Wilcoxon distribution (seeWilcoxon).In the case of ties, a tie correction is done accordingto Sachs (1997) and approximate p-values are computedfrom the standard normal distribution (seeNormal).
If both medians differ, one can correct for medians toincrease the specificity of the test.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Source
The algorithm for the Siegel-Tukey ranks wastaken from the code of Daniel Malter. See also theblog from Tal Galili (02/2010,https://www.r-statistics.com/2010/02/siegel-tukey-a-non-parametric-test-for-equality-in-variability-r-code/,accessed 2018-08-05).
References
Sachs, L. (1997),Angewandte Statistik. Berlin: Springer.
Siegel, S., Tukey, J. W. (1960), A nonparametric sum of ranksprocedure for relative spread in unpaired samples,Journal of the American Statistical Association55, 429–455.
Examples
## Sachs, 1997, p. 376A <- c(10.1, 7.3, 12.6, 2.4, 6.1, 8.5, 8.8, 9.4, 10.1, 9.8)B <- c(15.3, 3.6, 16.5, 2.9, 3.3, 4.2, 4.9, 7.3, 11.7, 13.7)siegelTukeyTest(A, B)## from example var.testx <- rnorm(50, mean = 0, sd = 2)y <- rnorm(30, mean = 1, sd = 1)siegelTukeyTest(x, y, median.corr = TRUE)## directional hypothesisA <- c(33, 62, 84, 85, 88, 93, 97)B <- c(4, 16, 48, 51, 66, 98)siegelTukeyTest(A, B, alternative = "greater")Skillings-Mack Test
Description
Performs Skillings-Mack rank sum test for partially balancedincomplete block designs or partially balanced random block designs.The null hypothesisH_0: \theta_i = \theta_j~~(i \ne j) is tested against thealternative H_{\mathrm{A}}: \theta_i \ne \theta_j, with at leastone inequality beeing strict.
Usage
skillingsMackTest(y, ...)## Default S3 method:skillingsMackTest(y, groups, blocks, ...)Arguments
y | a numeric vector of data values, or a list of numeric datavectors. |
groups | a vector or factor object giving the group for thecorresponding elements of |
blocks | a vector or factor object giving the block for thecorresponding elements of |
... | further arguments to be passed to or from methods. |
Details
The function has implemented the test of Skillings and Mack (1981).The test statistic is assymptotically chi-squared distributed withdf = k - 1 degrees of freedom.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Note
The input vector/matrix'y' must containNA.
References
Skillings, J. H., Mack, G.A. (1981) On the use of a Friedman-typestatistic in balanced and unbalanced block designs,Technometrics23, 171–177.
See Also
Examples
## Example from Hollander and Wolfe 1999,## originally appeared in Brady 1969.x <- cbind(c(3,1,5,2,0,0,0,0), c(5,3,4,NA,2,2,3,2), c(15,18,21,6,17,10,8,13))colnames(x) <- c("R", "A", "B")rownames(x) <- 1:8skillingsMackTest(x)## Compare with Friedman Test for CRB## Sachs, 1997, p. 675## Six persons (block) received six different diuretics## (A to F, treatment).## The responses are the Na-concentration (mval)## in the urine measured 2 hours after each treatment. y <- matrix(c(3.88, 5.64, 5.76, 4.25, 5.91, 4.33, 30.58, 30.14, 16.92,23.19, 26.74, 10.91, 25.24, 33.52, 25.45, 18.85, 20.45,26.67, 4.44, 7.94, 4.04, 4.4, 4.23, 4.36, 29.41, 30.72,32.92, 28.23, 23.35, 12, 38.87, 33.12, 39.15, 28.06, 38.23,26.65),nrow=6, ncol=6,dimnames=list(1:6, LETTERS[1:6]))print(y)friedmanTest(y)skillingsMackTest(y)Student-Newman-Keuls Test
Description
Performs Student-Newman-Keuls all-pairs comparisons test for normally distributeddata with equal group variances.
Usage
snkTest(x, ...)## Default S3 method:snkTest(x, g, ...)## S3 method for class 'formula'snkTest(formula, data, subset, na.action, ...)## S3 method for class 'aov'snkTest(x, ...)Arguments
x | a numeric vector of data values, a list of numeric datavectors or a fitted model object, usually anaov fit. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith normally distributed residuals and equal variancesStudent-Newman-Keuls test can be performed. A total ofm = k(k-1)/2hypotheses can be tested. The null hypothesisH_{ij}: \mu_i(x) = \mu_j(x) is tested in the two-tailed testagainst the alternativeA_{ij}: \mu_i(x) \ne \mu_j(x), ~~ i \ne j.
The p-values are computed from the Tukey-distribution.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Keuls, M. (1952) The use of the "studentized range"in connection with an analysis of variance,Euphytica1, 112–122.
Newman, D. (1939) The distribution of range insamples from a normal population, expressed interms of an independent estimate of standarddeviation,Biometrika31, 20–30.
Student (1927) Errors of routine analysis,Biometrika19, 151–164.
See Also
Examples
fit <- aov(weight ~ feed, chickwts)shapiro.test(residuals(fit))bartlett.test(weight ~ feed, chickwts)anova(fit)## also works with fitted objects of class aovres <- snkTest(fit)summary(res)summaryGroup(res)Testing against Ordered Alternatives (Spearman Test)
Description
Performs a Spearman type test for testing against ordered alternatives.
Usage
spearmanTest(x, ...)## Default S3 method:spearmanTest(x, g, alternative = c("two.sided", "greater", "less"), ...)## S3 method for class 'formula'spearmanTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
A one factorial design for dose finding comprises an ordered factor,.e. treatment with increasing treatment levels.The basic idea is to correlate the ranksR_{ij} with the increasingorder number1 \le i \le k of the treatment levels (Kloke and McKean 2015).More precisely,R_{ij} is correlated with the expected mid-value ranksunder the assumption of strictly increasing median responses.Let the expected mid-value rank of the first group denoteE_1 = \left(n_1 + 1\right)/2.The following expected mid-value ranks areE_j = n_{j-1} + \left(n_j + 1 \right)/2 for2 \le j \le k.The corresponding number of tied values for theith group isn_i. #The sum of squared residuals isD^2 = \sum_{i=1}^k \sum_{j=1}^{n_i} \left(R_{ij} - E_i \right)^2.Consequently, Spearman's rank correlation coefficient can be calculated as:
r_\mathrm{S} = \frac{6 D^2} {\left(N^3 - N\right)- C},
with
C = 1/2 - \sum_{c=1}^r \left(t_c^3 - t_c\right) +1/2 - \sum_{i=1}^k \left(n_i^3 - n_i \right)
andt_c the number of ties of thecth group of ties.Spearman's rank correlation coefficient can be tested forsignificance with at-test.For a one-tailed test the null hypothesis ofr_\mathrm{S} \le 0is rejected and the alternativer_\mathrm{S} > 0 is accepted if
r_\mathrm{S} \sqrt{\frac{\left(n-2\right)}{\left(1 - r_\mathrm{S}\right)}} > t_{v,1-\alpha},
withv = n - 2 degree of freedom.
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
Note
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers{0, 1, 2, ..., k} or letters {a, b, c, ...}.Otherwise the function may not select the correct valuesfor intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
Kloke, J., McKean, J. W. (2015)Nonparametric statistical methods using R.Boca Raton, FL: Chapman & Hall/CRC.
See Also
kruskalTest andshirleyWilliamsTestof the packagePMCMRplus,kruskal.test of the librarystats.
Examples
## Example from Sachs (1997, p. 402)x <- c(106, 114, 116, 127, 145, 110, 125, 143, 148, 151, 136, 139, 149, 160, 174)g <- gl(3,5)levels(g) <- c("A", "B", "C")## Chacko's testchackoTest(x, g)## Cuzick's testcuzickTest(x, g)## Johnson-Mehrotra testjohnsonTest(x, g)## Jonckheere-Terpstra testjonckheereTest(x, g)## Le's testleTest(x, g)## Spearman type testspearmanTest(x, g)## Murakami's BWS trend testbwsTrendTest(x, g)## Fligner-Wolfe testflignerWolfeTest(x, g)## Shan-Young-Kang testshanTest(x, g)Steel's Many-to-One Rank Test
Description
Performs Steel's non-parametric many-to-one comparisontest for Wilcox-type ranked data.
Usage
steelTest(x, ...)## Default S3 method:steelTest(x, g, alternative = c("greater", "less"), ...)## S3 method for class 'formula'steelTest( formula, data, subset, na.action, alternative = c("greater", "less"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For many-to-one comparisons (pairwise comparisons with one control)in an one-factorial balanced layout with non-normally distributedresiduals Steels's non-parametric single-step test can be performed.Let there bek treatment levels (excluding the control),thenk pairwise comparisons can be performed betweenthei-th treatment level and the control.H_i: \theta_0 = \theta_i is tested in the one-tailed case (less) againstA_i: \theta_0 > \theta_i, ~~ (1 \le i \le k).
For each control - treatment level the data are ranked in increasing order.The ranksumR_i for thei-th treatment level is comparedto a criticalR value and is significantly(p = 0.05) less,ifR_i \le R. For thealternative = "greater" the sign is changed.
The function does not return p-values. Instead the criticalR-valuesas given in the tables of USEPA (2002) for\alpha = 0.05 (one-sided, less)are looked up according to the balanced sample sizes (n) and the order number of thedose level (i).
Value
A list with class"osrt" that contains the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated statistic(s)
- crit.value
critical values for
\alpha = 0.05.- alternative
a character string describing the alternative hypothesis.
- parameter
the parameter(s) of the test distribution.
- dist
a string that denotes the test distribution.
There are print and summary methods available.
Source
The critical rank sum values were taken from Table E.5 of USEPA (2002).
USEPA (2002)Short-term Methods for Estimating theChronic Toxicity of Effluents and ReceivingWaters to Freshwater Organisms, 4th edition, EPA-821-R-02-013.
Note
Steel's Many-to-One Rank test is only applicable for balanced designs anddirectional hypotheses. An error message will occur, if the design is unbalanced.In the current implementation, only one-sided tests onthe level of\alpha = 0.05 can be performed.
References
Steel, R. G. D. (1959) A multiple comparison rank sum test:treatments versus control,Biometrics15, 560–572.
See Also
wilcox.test,pairwise.wilcox.test,manyOneUTest,flignerWolfeTest,shirleyWilliamsTest,kwManyOneDunnTest,kwManyOneNdwTest,kwManyOneConoverTest,print.osrt,summary.osrt
Examples
## Example from Sachs (1997, p. 402)x <- c(106, 114, 116, 127, 145,110, 125, 143, 148, 151,136, 139, 149, 160, 174)g <- gl(3,5)levels(g) <- c("0", "I", "II")## Steel's TeststeelTest(x ~ g)## Example from USEPA (2002):## Reproduction data from a Ceriodaphnia dubia## 7-day chronic test to several concentrations## of effluent. Dose level 50% is excluded.x <- c(20, 26, 26, 23, 24, 27, 26, 23, 27, 24,13, 15, 14, 13, 23, 26, 0, 25, 26, 27,18, 22, 13, 13, 23, 22, 20, 22, 23, 22,14, 22, 20, 23, 20, 23, 25, 24, 25, 21,9, 0, 9, 7, 6, 10, 12, 14, 9, 13,rep(0,10))g <- gl(6, 10)levels(g) <- c("Control", "3%", "6%", "12%", "25%", "50%")## NOEC at 3%, LOEC at 6%steelTest(x ~ g, subset = g != "50%", alternative = "less")Steel's k-Treatments vs. Control Test
Description
Performs the non-parametric Steel's testfor simultaneously testing k-treatments vs. one control.
Usage
steelsKSampleTest(x, ...)## Default S3 method:steelsKSampleTest(x, g, alternative = c("two.sided", "greater", "less"), ...)## S3 method for class 'formula'steelsKSampleTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
It testsH: F(i) = F(0), ~ i \le k, againstA: F(i) > F(0) (greater) with at least one inequality being strict.
The function is a wrapper function that callsSteel.test ofthe packagekSamples with argumentmethod = "asymptotic".
Value
A list with class"htest" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated quantile of the test statistic.
- p.value
the p-value for the test.
- parameter
the parameters of the test statistic, if any.
- alternative
a character string describing the alternative hypothesis.
- estimates
the estimates, if any.
- null.value
the estimate under the null hypothesis, if any.
References
Scholz, F. and Zhu, A. (2019). kSamples: K-Sample Rank Tests andtheir Combinations. R package version 1.2-9.https://CRAN.R-project.org/package=kSamples
Steel, R. G. D. (1959) A Multiple Comparison Rank Sum Test:Treatments Versus Control,Biometrics15, 560–572.
See Also
Examples
## Example from Sachs (1997, p. 402)x <- c(106, 114, 116, 127, 145,110, 125, 143, 148, 151,136, 139, 149, 160, 174)g <- gl(3,5)levels(g) <- c("0", "I", "II")## Steel's TeststeelsKSampleTest(x ~ g, alternative = "greater")## Example from USEPA (2002):## Reproduction data from a Ceriodaphnia dubia## 7-day chronic test to several concentrations## of effluent. Dose level 50% is excluded.x <- c(20, 26, 26, 23, 24, 27, 26, 23, 27, 24,13, 15, 14, 13, 23, 26, 0, 25, 26, 27,18, 22, 13, 13, 23, 22, 20, 22, 23, 22,14, 22, 20, 23, 20, 23, 25, 24, 25, 21,9, 0, 9, 7, 6, 10, 12, 14, 9, 13,rep(0,10))g <- gl(6, 10)levels(g) <- c("Control", "3%", "6%", "12%", "25%", "50%")## NOEC at 3%, LOEC at 6%steelsKSampleTest(x ~ g, subset = g != "50%", alternative = "less")Step Down Trend Tests
Description
Performs step-down trend test procedures for monotone responsesto detect NOEC (LOEC) according to OECD (2006).
Usage
stepDownTrendTest(x, ...)## Default S3 method:stepDownTrendTest( x, g, test = c("leTest", "spearmanTest", "jonckheereTest", "cuzickTest", "chackoTest", "johnsonTest"), alternative = c("two.sided", "greater", "less"), continuity = FALSE, ...)## S3 method for class 'formula'stepDownTrendTest( formula, data, subset, na.action, test = c("leTest", "spearmanTest", "jonckheereTest", "cuzickTest", "chackoTest", "johnsonTest"), alternative = c("two.sided", "greater", "less"), continuity = FALSE, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
test | the trend test that shall be performed. Defaults to |
alternative | the alternative hypothesis. Defaults to |
continuity | logical indicator whether a continuity correctionshall be performed. Only relevant for |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
According to OECD 2006 one can perform a test for trendon responses from all dose groups including the control.If the trend test is significant at the 0.05 level, thehigh dose group is omitted, and the trendstatistic with the remaining dose groups is re-computeThe procedure is continued until the trend test isfirst non-significant at the 0.05 level, then stop.
The NOEC is the highest doseremaining at this stage. If this test is significantwhen only the lowest dose and control remain,then a NOEC cannot be established from the data.
Value
A list with class"trendPMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- dist
a string that denotes the test distribution.
Note
Factor labels forg must be assigned in such a way,that they can be increasingly ordered from zero-dosecontrol to the highest dose level, e.g. integers {0, 1, 2, ..., k} orletters {a, b, c, ...}. Otherwise the function may notselect the correct values for intended zero-dose control.
It is safer, to i) label the factor levels as given above,and to ii) sort the data according to increasing dose-levelsprior to call the function (seeorder,factor).
References
OECD (2006)Current Approaches in the StatisticalAnalysis of Ecotoxicity Data: A Guidance to Application,OECD Series on Testing and Assessment52,Paris: Organisation for Econonomic Co-operation and Development.
See Also
leTest,jonckheereTest,spearmanTest,cuzickTest,chackoTest,johnsonTest
Examples
res <- stepDownTrendTest(Y ~ DOSE, data = trout, test = "jonckheereTest", alternative = "less")## print methodres## summary methodsummary(res)Summarize an PMCMR Object
Description
Summarize an object of classPMCMR.
Usage
## S3 method for class 'PMCMR'summary(object, ...)Arguments
object | an object of class |
... | further arguments. Currenly ignored. |
Value
A detailed output of all pairwise hypotheses,the test statistics, the corresponding p-values andsymbols that indicates the level of significance.
See Also
Examples
ans <- vanWaerdenAllPairsTest(count ~ spray, InsectSprays)summary(ans)Summarize an gesdTest Object
Description
Summarize an object of classgesdTest.
Usage
## S3 method for class 'gesdTest'summary(object, ...)Arguments
object | an object of class |
... | further arguments. Currenly ignored. |
Object Summary for class"mandel"
Description
summary.mandel is a functionused to produce result summaries of the results ofthe functionsmandelhTest ormandelkTest.
Usage
## S3 method for class 'mandel'summary(object, ...)Arguments
object | an object of class |
... | further arguments. Currently ignored. |
See Also
Summarize an osrt Object
Description
Summarize an object of classosrt.
Usage
## S3 method for class 'osrt'summary(object, ...)Arguments
object | an object of class |
... | further arguments. Currenly ignored. |
See Also
Summarize an trendPMCMR Object
Description
Summarize an object of classtrendPMCMR.
Usage
## S3 method for class 'trendPMCMR'summary(object, ...)Arguments
object | an object of class |
... | further arguments. Currenly ignored. |
Value
A detailed output of all pairwise hypotheses,the test statistics, the corresponding p-values andsymbols that indicates the level of significance.
See Also
Grouped Summary of an PMCMR Object
Description
Performes a grouped summary on an PMCMR object.
Usage
summaryGroup(x, alpha = 0.05, ...)Arguments
x | an object of class |
alpha | the selected alpha-level. Defaults to 0.05. |
... | further arguments. Currently ignored. |
Value
Provides summary statistics for each factor leveland a letter symbol, whereas different letters indicatesignificant differences between factor levels based on theselected level of alpha.
See Also
Tamhane-Dunnett Many-to-One Comparison Test
Description
Performs Tamhane-Dunnett's multiple comparisons test with one control.For many-to-one comparisons in an one-factorial layoutwith normally distributed residuals and unequal variancesTamhane-Dunnett's test can be used.LetX_{0j} denote a continuous random variablewith thej-the realization of the control group(1 \le j \le n_0) andX_{ij} thej-the realizationin thei-th treatment group (1 \le i \le k).Furthermore, the total sample size isN = n_0 + \sum_{i=1}^k n_i.A total ofm = k hypotheses can be tested: The null hypothesis isH_{i}: \mu_i = \mu_0 is tested against the alternativeA_{i}: \mu_i \ne \mu_0 (two-tailed). Tamhane-Dunnett's teststatistics are given by
t_{i} \frac{\bar{X}_i - \bar{X_0}} {\left( s^2_0 / n_0 + s^2_i / n_i \right)^{1/2} } ~~ (1 \le i \le k)
The null hypothesis is rejected if|t_{i}| > T_{kv_{i}\rho_{ij}\alpha} (two-tailed),with
v_i = n_0 + n_i - 2
degree of freedom and the correlation
\rho_{ii} = 1, ~ \rho_{ij} = 0 ~ (i \ne j).
The p-values are computed from the multivariate-tdistribution as implemented in the functionpmvt distribution.
Usage
tamhaneDunnettTest(x, ...)## Default S3 method:tamhaneDunnettTest(x, g, alternative = c("two.sided", "greater", "less"), ...)## S3 method for class 'formula'tamhaneDunnettTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), ...)## S3 method for class 'aov'tamhaneDunnettTest(x, alternative = c("two.sided", "greater", "less"), ...)Arguments
x | a numeric vector of data values, a list of numeric datavectors or a fitted model object, usually anaov fit. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis.Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
OECD (ed. 2006)Current approaches in the statistical analysisof ecotoxicity data: A guidance to application - Annexes. OECD Serieson testing and assessment, No. 54.
See Also
Examples
set.seed(245)mn <- c(1, 2, 2^2, 2^3, 2^4)x <- rep(mn, each=5) + rnorm(25)g <- factor(rep(1:5, each=5))fit <- aov(x ~ g - 1)shapiro.test(residuals(fit))bartlett.test(x ~ g - 1)anova(fit)## works with object of class aovsummary(tamhaneDunnettTest(fit, alternative = "greater"))Tamhane's T2 Test
Description
Performs Tamhane's T2 (or T2') all-pairs comparison test for normally distributeddata with unequal variances.
Usage
tamhaneT2Test(x, ...)## Default S3 method:tamhaneT2Test(x, g, welch = TRUE, ...)## S3 method for class 'formula'tamhaneT2Test(formula, data, subset, na.action, welch = TRUE, ...)## S3 method for class 'aov'tamhaneT2Test(x, welch = TRUE, ...)Arguments
x | a numeric vector of data values, a list of numeric datavectors or a fitted model object, usually anaov fit. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
welch | indicates, whether Welch's approximate solution forcalculating the degree of freedom shall be used or, as usually, |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith normally distributed residuals but unequal groups variancesthe T2 test (or T2' test) of Tamhane can be performed.LetX_{ij} denote a continuous random variablewith thej-the realization (1 \le j \le n_i)in thei-th group (1 \le i \le k). Furthermore, the totalsample size isN = \sum_{i=1}^k n_i. A total ofm = k(k-1)/2hypotheses can be tested: The null hypothesis isH_{ij}: \mu_i = \mu_j ~~ (i \ne j) is tested against the alternativeA_{ij}: \mu_i \ne \mu_j (two-tailed). Tamhane T2 all-pairstest statistics are given by
t_{ij} \frac{\bar{X}_i - \bar{X_j}} {\left( s^2_j / n_j + s^2_i / n_i \right)^{1/2}}, ~~ (i \ne j)
withs^2_i the variance of thei-th group.The null hypothesis is rejected (two-tailed) if
\mathrm{Pr} \left\{ |t_{ij}| \ge t_{v_{ij}\alpha'/2} | \mathrm{H} \right\}_{ij} = \alpha.
T2 test uses Welch's approximate solution forcalculating the degree of freedom.
v_{ij} = \frac{\left( s^2_i / n_i + s^2_j / n_j \right)^2} {s^4_i / n^2_i \left(n_i - 1\right) + s^4_j / n^2_j \left(n_j - 1\right)}.
T2' test applies the following approximation for the degree of freedom
v_{ij} = n_i + n_j - 2
The p-values are computed from theTDist-distributionand adjusted according to Dunn-Sidak.
p'_{ij} = \min \left\{1, ~ (1 - (1 - p_{ij})^m)\right\}
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
Note
T2 test is basically an all-pairs pairwise-t-test. Similar resultscan be obtained withpairwise.t.test(..., var.equal=FALSE, p.adjust.mehod = FALSE).
A warning message appearsin the modified T2' test, if none of in Tamhane (1979) given conditionsfor nearly balancedsample sizes and nearly balanced standard errors is true.
Thanks to Sirio Bolaños for his kind suggestion for adding T2' testinto this function.
References
Tamhane, A. C. (1979) A Comparison of Procedures for Multiple Comparisonsof Means with Unequal Variances,Journal of the AmericanStatistical Association74, 471–480.
See Also
dunnettT3TesturyWigginsHochbergTest
Examples
fit <- aov(weight ~ feed, chickwts)shapiro.test(residuals(fit))bartlett.test(weight ~ feed, chickwts) # var1 = varNanova(fit)## also works with fitted objects of class aovres <- tamhaneT2Test(fit)summary(res)summaryGroup(res)res## compare with pairwise.t.testWT <- pairwise.t.test(chickwts$weight, chickwts$feed, pool.sd = FALSE, p.adjust.method = "none")p.adj.sidak <- function(p, m) sapply(p, function(p) min(1, 1 - (1 - p)^m))p.raw <- as.vector(WT$p.value)m <- length(p.raw[!is.na(p.raw)])PADJ <- matrix(ans <- p.adj.sidak(p.raw, m), nrow = 5, ncol = 5)colnames(PADJ) <- colnames(WT$p.value)rownames(PADJ) <- rownames(WT$p.value)PADJ## same without Welch's approximate solutionsummary(T2b <- tamhaneT2Test(fit, welch = FALSE))Convert a PMCMR or osrt Object to a Data.Frame
Description
The functions converts a list object of class"PMCMR"or"osrt" into a data.frame.
Usage
toTidy(mod, ...)Arguments
mod | an object of class |
... | further arguments. Currently ignored. |
Value
A data.frame.
Author(s)
Indrajeet Patil (via email, 2020-1022),modified by Thorsten Pohlert
Examples
res <- tukeyTest(weight ~ Diet, data = ChickWeight, subset = Time == 21)toTidy(res)Data from a Dose-Response Experiment with Trouts
Description
This data set contains results from a dose-response experiment with trouts.The experiment was conducted with five doses of 10, 25, 60, 150 and1000 ppm, respectively, plus a zero-dose control. The response istrout weight in mg.
Format
A data frame with 65 observations on the following 5 variables.
- CONC
a numeric vector of dose concentration in ppm
- DOSE
a factor with levels
123456- REPA
a factor with levels
12- REPC
a factor with levels
12- Y
a numeric vector of trout weight in mg
Source
ENV/JM/MONO(2006)18/ANN, page 113.
References
OECD (ed. 2006)Current approaches in the statistical analysisof ecotoxicity data: A guidance to application - Annexes. OECD Serieson testing and assessment, No. 54, (ENV/JM/MONO(2006)18/ANN).
Tukey's Multiple Comparison Test
Description
Performs Tukey's all-pairs comparisons test for normally distributeddata with equal group variances.
Usage
tukeyTest(x, ...)## Default S3 method:tukeyTest(x, g, ...)## S3 method for class 'formula'tukeyTest(formula, data, subset, na.action, ...)## S3 method for class 'aov'tukeyTest(x, ...)Arguments
x | a numeric vector of data values, a list of numeric datavectors or a fitted model object, usually anaov fit. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith normally distributed residuals and equal variancesTukey's test can be performed.LetX_{ij} denote a continuous random variablewith thej-the realization (1 \le j \le n_i)in thei-th group (1 \le i \le k). Furthermore, the totalsample size isN = \sum_{i=1}^k n_i. A total ofm = k(k-1)/2hypotheses can be tested: The null hypothesis isH_{ij}: \mu_i = \mu_j ~~ (i \ne j) is tested against the alternativeA_{ij}: \mu_i \ne \mu_j (two-tailed). Tukey's all-pairs teststatistics are given by
t_{ij} \frac{\bar{X}_i - \bar{X_j}} {s_{\mathrm{in}} \left(1/n_j + 1/n_i\right)^{1/2}}, ~~ (i \ne j)
withs^2_{\mathrm{in}} the within-group ANOVA variance.The null hypothesis is rejected if|t_{ij}| > q_{vm\alpha} / \sqrt{2},withv = N - k degree of freedom. The p-values are computedfrom theTukey distribution.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Sachs, L. (1997)Angewandte Statistik, New York: Springer.
Tukey, J. (1949) Comparing Individual Means in the Analysis of Variance,Biometrics5, 99–114.
See Also
Examples
fit <- aov(weight ~ feed, chickwts)shapiro.test(residuals(fit))bartlett.test(weight ~ feed, chickwts)anova(fit)## also works with fitted objects of class aovres <- tukeyTest(fit)summary(res)summaryGroup(res)Ury, Wiggins, Hochberg Test
Description
Performs Ury-Wiggins and Hochberg's all-pairs comparison testfor normally distributed data with unequal variances.
Usage
uryWigginsHochbergTest(x, ...)## Default S3 method:uryWigginsHochbergTest(x, g, p.adjust.method = p.adjust.methods, ...)## S3 method for class 'formula'uryWigginsHochbergTest( formula, data, subset, na.action, p.adjust.method = p.adjust.methods, ...)## S3 method for class 'aov'uryWigginsHochbergTest(x, p.adjust.method = p.adjust.methods, ...)Arguments
x | a numeric vector of data values, a list of numeric datavectors or a fitted model object, usually anaov fit. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
p.adjust.method | method for adjusting p values(see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith normally distributed residuals but unequal groups variancesthe tests of Ury-Wiggins and Hochberg can be performed.LetX_{ij} denote a continuous random variablewith thej-the realization (1 \le j \le n_i)in thei-th group (1 \le i \le k). Furthermore, the totalsample size isN = \sum_{i=1}^k n_i. A total ofm = k(k-1)/2hypotheses can be tested: The null hypothesis isH_{ij}: \mu_i = \mu_j ~~ (i \ne j) is tested against the alternativeA_{ij}: \mu_i \ne \mu_j (two-tailed). Ury-Wiggins and Hochbergall-pairs test statistics are given by
t_{ij} \frac{\bar{X}_i - \bar{X_j}} {\left( s^2_j / n_j + s^2_i / n_i \right)^{1/2}}, ~~ (i \ne j)
withs^2_i the variance of thei-th group.The null hypothesis is rejected (two-tailed) if
\mathrm{Pr} \left\{ |t_{ij}| \ge t_{v_{ij}\alpha'/2} | \mathrm{H} \right\}_{ij} = \alpha,
with Welch's approximate equation for degree of freedom as
v_{ij} = \frac{\left( s^2_i / n_i + s^2_j / n_j \right)^2} {s^4_i / n^2_i \left(n_i - 1\right) + s^4_j / n^2_j \left(n_j - 1\right)}.
The p-values are computed from theTDist-distribution.The type of test dependson the selected p-value adjustment method (see alsop.adjust):
- bonferroni
the Ury-Wiggins test is performed with Bonferroni adjustedp-values.
- hochberg
the Hochberg test is performed with Hochberg's adjustedp-values
.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Hochberg, Y. (1976) A Modification of the T-Method of MultipleComparisons for a One-Way Layout With Unequal Variances,Journal of the American Statistical Association71, 200–203.
Ury, H. and Wiggins, A. D. (1971) Large Sample and OtherMultiple Comparisons Among Means,British Journal ofMathematical and Statistical Psychology24, 174–194.
See Also
dunnettT3TesttamhaneT2TestTDist
Examples
fit <- aov(weight ~ feed, chickwts)shapiro.test(residuals(fit))bartlett.test(weight ~ feed, chickwts) # var1 = varNanova(fit)## also works with fitted objects of class aovres <- uryWigginsHochbergTest(fit)summary(res)summaryGroup(res)van-der-Waerden's All-Pairs Comparison Normal Scores Test
Description
Performs van-der-Waerden all-pairs comparisonnormal scores test.
Usage
vanWaerdenAllPairsTest(x, ...)## Default S3 method:vanWaerdenAllPairsTest( x, g, p.adjust.method = c("single-step", p.adjust.methods), ...)## S3 method for class 'formula'vanWaerdenAllPairsTest( formula, data, subset, na.action, p.adjust.method = c("single-step", p.adjust.methods), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
p.adjust.method | method for adjusting p values (see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For all-pairs comparisons in an one-factorial layoutwith non-normally distributed residuals van-der-Waerden'snormal scores transformation can be used prior toan all-pairs comparison test. A total ofm = k(k-1)/2hypotheses can be tested. The null hypothesisH_{ij}: F_i(x) = F_j(x) is tested in the two-tailed testagainst the alternativeA_{ij}: F_i(x) \ne F_j(x), ~~ i \ne j.Forp.adjust.method = "single-step" theTukey's studentized range distribution is used to calculatep-values (seeTukey). Otherwise, thet-distribution is used for the calculation of p-valueswith a latter p-value adjustment asperformed byp.adjust.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Conover, W. J., Iman, R. L. (1979)On multiple-comparisons procedures,Tech. Rep. LA-7677-MS, Los Alamos Scientific Laboratory.
van der Waerden, B. L. (1952) Order tests for the two-sampleproblem and their power,Indagationes Mathematicae14, 453–458.
See Also
vanWaerdenTest,vanWaerdenManyOneTest,normOrder.
van-der-Waerden's Many-One Comparisons Normal Scores Test
Description
Performs van-der-Waerden's multiple comparisonnormal scores test with one control.
Usage
vanWaerdenManyOneTest(x, ...)## Default S3 method:vanWaerdenManyOneTest( x, g, alternative = c("two.sided", "greater", "less"), p.adjust.method = c("single-step", p.adjust.methods), ...)## S3 method for class 'formula'vanWaerdenManyOneTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), p.adjust.method = c("single-step", p.adjust.methods), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
p.adjust.method | method for adjusting p values (see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For many-to-one comparisons in an one-factorial layoutwith non-normally distributed residuals van-der-Waerden'snormal scores transformation can be used prior toa many-to-one comparison test. A total ofm = k-1hypotheses can be tested. The null hypothesisH_{i}: F_0(x) = F_i(x) is tested in the two-tailed testagainst the alternativeA_{i}: F_0(x) \ne F_i(x), ~~ 1 \le i \le k-1.Forp.adjust.method = "single-step" themultivariate t distribution is used to calculatep-values (seepmvt). Otherwise, thet-distribution is used for the calculation of p-valueswith a latter p-value adjustment asperformed byp.adjust.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Conover, W. J., Iman, R. L. (1979)On multiple-comparisons procedures,Tech. Rep. LA-7677-MS, Los Alamos Scientific Laboratory.
van der Waerden, B. L. (1952) Order tests for the two-sampleproblem and their power,Indagationes Mathematicae14, 453–458.
See Also
vanWaerdenTest,vanWaerdenAllPairsTest,pmvt.
Examples
## Data set PlantGrowth## Global testvanWaerdenTest(weight ~ group, data = PlantGrowth)## van-der-Waerden's many-one comparison testans <- vanWaerdenManyOneTest(weight ~ group, data = PlantGrowth, p.adjust.method = "holm")summary(ans)van der Waerden's Normal Scores Test
Description
Performs van der Waerden's normal scores test.
Usage
vanWaerdenTest(x, ...)## Default S3 method:vanWaerdenTest(x, g, ...)## S3 method for class 'formula'vanWaerdenTest(formula, data, subset, na.action, ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For one-factorial designs with non-normally distributedresiduals van der Waerden's normal scores test can be performed to testthe H_0: F_1(x) = F_2(x) = \ldots = F_k(x) againstthe H_\mathrm{A}: F_i (x) \ne F_j(x)~ (i \ne j) with at leastone strict inequality.
Note
A tie correction is not applied in this function.
References
Conover, W. J., Iman, R. L. (1979)On multiple-comparisons procedures,Tech. Rep. LA-7677-MS, Los Alamos Scientific Laboratory.
van der Waerden, B. L. (1952) Order tests for the two-sampleproblem and their power,Indagationes Mathematicae14, 453–458.
See Also
Examples
vanWaerdenTest(count ~ spray, data = InsectSprays)Welchs's Many-To-One Comparison Test
Description
Performs Welchs's t-test for multiple comparisons with one control.
Usage
welchManyOneTTest(x, ...)## Default S3 method:welchManyOneTTest( x, g, alternative = c("two.sided", "greater", "less"), p.adjust.method = p.adjust.methods, ...)## S3 method for class 'formula'welchManyOneTTest( formula, data, subset, na.action, alternative = c("two.sided", "greater", "less"), p.adjust.method = p.adjust.methods, ...)## S3 method for class 'aov'welchManyOneTTest( x, alternative = c("two.sided", "greater", "less"), p.adjust.method = p.adjust.methods, ...)Arguments
x | a numeric vector of data values, a list of numeric datavectors or a fitted model object, usually anaov fit. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis.Defaults to |
p.adjust.method | method for adjusting p values(see |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
For many-to-one comparisons in an one-factorial layoutwith normally distributed residuals and unequal variancesWelch's t-test can be used. A total ofm = k-1hypotheses can be tested. The null hypothesisH_{i}: \mu_0(x) = \mu_i(x) is tested in the two-tailed testagainst the alternativeA_{i}: \mu_0(x) \ne \mu_i(x), ~~ 1 \le i \le k-1.
This function is basically a wrapper function fort.test(..., var.equal = FALSE). The p-values for the testare calculated from the t distributionand can be adusted with any method that is implemented inp.adjust.methods.
Value
A list with class"PMCMR" containing the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
lower-triangle matrix of the estimatedquantiles of the pairwise test statistics.
- p.value
lower-triangle matrix of the p-values for the pairwise tests.
- alternative
a character string describing the alternative hypothesis.
- p.adjust.method
a character string describing the method for p-valueadjustment.
- model
a data frame of the input data.
- dist
a string that denotes the test distribution.
References
Welch, B. L. (1947) The generalization of "Student's" problemwhen several different population variances are involved,Biometrika34, 28–35.
Welch, B. L. (1951) On the comparison of several mean values:An alternative approach,Biometrika38, 330–336.
See Also
pairwise.t.test,t.test,p.adjust,tamhaneDunnettTest
Examples
set.seed(245)mn <- rep(c(1, 2^(1:4)), each=5)sd <- rep(1:5, each=5)x <- mn + rnorm(25, sd = sd)g <- factor(rep(1:5, each=5))fit <- aov(x ~ g)shapiro.test(residuals(fit))bartlett.test(x ~ g)anova(fit)summary(welchManyOneTTest(fit, alternative = "greater", p.adjust="holm"))Williams Trend Test
Description
Performs Williams' test for contrasting increasing (decreasing) dose levels of a treatment.
Usage
williamsTest(x, ...)## Default S3 method:williamsTest(x, g, alternative = c("greater", "less"), ...)## S3 method for class 'formula'williamsTest( formula, data, subset, na.action, alternative = c("greater", "less"), ...)## S3 method for class 'aov'williamsTest(x, alternative = c("greater", "less"), ...)Arguments
x | a numeric vector of data values, or a list of numeric datavectors. |
... | further arguments to be passed to or from methods. |
g | a vector or factor object giving the group for thecorresponding elements of |
alternative | the alternative hypothesis. Defaults to |
formula | a formula of the form |
data | an optional matrix or data frame (or similar: see |
subset | an optional vector specifying asubset of observations to be used. |
na.action | a function which indicates what should happen whenthe data contain |
Details
Williams' test is a step-down trend test for testing several treatment levelswith a zero control in a one-factorial design with normally distributederrors of homogeneous variance. Let there bek groups including the control and letthe zero dose level be indicated withi = 0 and the treatmentlevels indicated as1 \le i \le m, then the followingm = k - 1 hypotheses are tested:
\begin{array}{ll}\mathrm{H}_{m}: \bar{x}_0 = m_1 = \ldots = m_m, & \mathrm{A}_{m}: \bar{x}_0 \le m_1 \le \ldots m_m, \bar{x}_0 < m_m \\\mathrm{H}_{m-1}: \bar{x}_0 = m_1 = \ldots = m_{m-1}, & \mathrm{A}_{m-1}: \bar{x}_0 \le m_1 \le \ldots m_{m-1}, \bar{x}_0 < m_{m-1} \\\vdots & \vdots \\\mathrm{H}_{1}: \bar{x}_0 = m_1, & \mathrm{A}_{1}: \bar{x}_0 < m_1,\\\end{array}
wherem_i denotes the isotonic mean of theith dose level group.
William's test bases on a order restriction:
\mu_i^{*} = \max_{1\le u \le i}~\min_{i \le v \le m}~ \sum_{j=u}^v n_j \bar{x}_j^{*} ~/~ \sum_{j=u}^v n_j \qquad (1 \le i \le m),
where\bar{x}_j^* denotes thej-th isotonicmean estimated with isotonic regression using thepool adjacent violators algorithm (PAVA) with the vectorof means\left\{\bar{x}_1, \bar{x}_2, \ldots, \bar{x}_m\right\}^Tand the vector of weights\left\{n_1, n_2, \ldots, n_m\right\}^T.
For the alternative hypothesis of decreasing trend,max and min are interchanged in the above Equation.
Thei-the test statistic is calculated as follows:
\bar{t}_i = \frac{\mu_m^* - \bar{x}_0}{s_{\mathrm{E}} \sqrt{1/n_m - 1/n_0}}
The procedure starts from the highest dose level (m) to the the lowest dose level (1) andstops at the first non-significant test. The consequent lowest effect doseis the treatment level of the previous test number.
The function does not return p-values. Instead the critical t-valuesas given in the tables of Williams (1972) for\alpha = 0.05 (one-sided)are looked up according to the degree of freedoms (v) and the order number of thedose level (i) and (potentially) modified according to the given extrapolationcoefficient\beta.
Non tabulated values are linearly interpolated as recommended by Williams (1972).The functionapprox is used.
For the comparison of the first dose level (i = 1) with the control, the critical t-valuefrom the Student t distribution is used (TDist).
Value
A list with class"osrt" that contains the following components:
- method
a character string indicating what type of test was performed.
- data.name
a character string giving the name(s) of the data.
- statistic
the estimated statistic(s)
- crit.value
critical values for
\alpha = 0.05.- alternative
a character string describing the alternative hypothesis.
- parameter
the parameter(s) of the test distribution.
- dist
a string that denotes the test distribution.
There are print and summary methods available.
Source
The source code for the application of the pool adjacent violatorstheorem to calculate the isotonic meanswas taken from the file"pava.f", which is included in thepackageIso:
Rolf Turner (2015). Iso: Functions to Perform Isotonic Regression. Rpackage version 0.0-17.https://CRAN.R-project.org/package=Iso.
The filepava.f is a Ratfor modification of Algorithm AS 206.1:
Bril, G., Dykstra, R., Pillers, C., Robertson, T. (1984)Statistical Algorithms: Algorithm AS 206: IsotonicRegression in Two Independent Variables,Appl. Statist.,34, 352–357.
The Algorith AS 206 is available from StatLibhttps://lib.stat.cmu.edu/apstat/. The Royal Statistical Societyholds the copyright to these routines,but has given its permission for their distribution provided thatno fee is charged.
Note
In the current implementation, only tests on the level of\alpha = 0.05can be performed. The included extrapolation function assumes eithera balanced design, or designs, where the number of replicates in the control excdeeds the number of replicatesin the treatment levels. A warning message appears, if the followingcondition is not met,1 \le n_0 / n_i \le 6 for1 \le i \le m.
References
Williams, D. A. (1971) A test for differences between treatment meanswhen several dose levels are compared with a zero dose control,Biometrics27, 103–117.
Williams, D. A. (1972) The comparison of several dose levels with a zerodose control,Biometrics28, 519–531.
See Also
TDist,approx,print.osrt,summary.osrt
Examples
## Example from Sachs (1997, p. 402)x <- c(106, 114, 116, 127, 145,110, 125, 143, 148, 151,136, 139, 149, 160, 174)g <- gl(3,5)levels(g) <- c("0", "I", "II")## Williams TestwilliamsTest(x ~ g)