Overview of selection features:

tidyselect implements a DSL for selecting variables. It provides helpersfor selecting variables:

• var1:var10: variables lying betweenvar1 on the left andvar10 on the right.

• starts_with("a"): names that start with"a".

• ends_with("z"): names that end with"z".

• contains("b"): names that contain"b".

• matches("x.y"): names that match regular expressionx.y.

• num_range(x, 1:4): names following the pattern,x1,x2, ...,x4.

• all_of(vars)/any_of(vars):matches names stored in the character vectorvars.all_of(vars) willerror if the variables aren't present;any_of(var) will match just thevariables that exist.

• everything(): all variables.

• last_col(): furthest column on the right.

• where(is.numeric): all variables whereis.numeric() returnsTRUE.

As well as operators for combining those selections:

• !selection: only variables that don't matchselection.

• selection1 & selection2: only variables included in bothselection1 andselection2.

• selection1 | selection2: all variables that match eitherselection1 orselection2.

When writing code inside packages you can substitute"var" forvar to avoidR CMD check notes.

library(tidyverse)# For better printingiris<-as_tibble(iris)

starwars%>%select(height)#> # A tibble: 87 x 1#>   height#>    <int>#> 1    172#> 2    167#> 3     96#> 4    202#> # i 83 more rowsiris%>%pivot_longer(Sepal.Length)#> # A tibble: 150 x 6#>   Sepal.Width Petal.Length Petal.Width Species name         value#>         <dbl>        <dbl>       <dbl> <fct>   <chr>        <dbl>#> 1         3.5          1.4         0.2 setosa  Sepal.Length   5.1#> 2         3            1.4         0.2 setosa  Sepal.Length   4.9#> 3         3.2          1.3         0.2 setosa  Sepal.Length   4.7#> 4         3.1          1.5         0.2 setosa  Sepal.Length   4.6#> # i 146 more rows

starwars%>%select(homeworld,height,mass)#> # A tibble: 87 x 3#>   homeworld height  mass#>   <chr>      <int> <dbl>#> 1 Tatooine     172    77#> 2 Tatooine     167    75#> 3 Naboo         96    32#> 4 Tatooine     202   136#> # i 83 more rows

iris%>%pivot_longer(c(Sepal.Length,Petal.Length))#> # A tibble: 300 x 5#>   Sepal.Width Petal.Width Species name         value#>         <dbl>       <dbl> <fct>   <chr>        <dbl>#> 1         3.5         0.2 setosa  Sepal.Length   5.1#> 2         3.5         0.2 setosa  Petal.Length   1.4#> 3         3           0.2 setosa  Sepal.Length   4.9#> 4         3           0.2 setosa  Petal.Length   1.4#> # i 296 more rows

Operators:

The: operator selects a range of consecutive variables:

starwars%>%select(name:mass)#> # A tibble: 87 x 3#>   name           height  mass#>   <chr>           <int> <dbl>#> 1 Luke Skywalker    172    77#> 2 C-3PO             167    75#> 3 R2-D2              96    32#> 4 Darth Vader       202   136#> # i 83 more rows

The! operator negates a selection:

starwars%>%select(!(name:mass))#> # A tibble: 87 x 11#>   hair_color skin_color  eye_color birth_year sex   gender    homeworld species#>   <chr>      <chr>       <chr>          <dbl> <chr> <chr>     <chr>     <chr>#> 1 blond      fair        blue            19   male  masculine Tatooine  Human#> 2 <NA>       gold        yellow         112   none  masculine Tatooine  Droid#> 3 <NA>       white, blue red             33   none  masculine Naboo     Droid#> 4 none       white       yellow          41.9 male  masculine Tatooine  Human#> # i 83 more rows#> # i 3 more variables: films <list>, vehicles <list>, starships <list>iris%>%select(!c(Sepal.Length,Petal.Length))#> # A tibble: 150 x 3#>   Sepal.Width Petal.Width Species#>         <dbl>       <dbl> <fct>#> 1         3.5         0.2 setosa#> 2         3           0.2 setosa#> 3         3.2         0.2 setosa#> 4         3.1         0.2 setosa#> # i 146 more rowsiris%>%select(!ends_with("Width"))#> # A tibble: 150 x 3#>   Sepal.Length Petal.Length Species#>          <dbl>        <dbl> <fct>#> 1          5.1          1.4 setosa#> 2          4.9          1.4 setosa#> 3          4.7          1.3 setosa#> 4          4.6          1.5 setosa#> # i 146 more rows

& and| take the intersection or the union of two selections:

iris%>%select(starts_with("Petal")&ends_with("Width"))#> # A tibble: 150 x 1#>   Petal.Width#>         <dbl>#> 1         0.2#> 2         0.2#> 3         0.2#> 4         0.2#> # i 146 more rowsiris%>%select(starts_with("Petal")|ends_with("Width"))#> # A tibble: 150 x 3#>   Petal.Length Petal.Width Sepal.Width#>          <dbl>       <dbl>       <dbl>#> 1          1.4         0.2         3.5#> 2          1.4         0.2         3#> 3          1.3         0.2         3.2#> 4          1.5         0.2         3.1#> # i 146 more rows

To take the difference between two selections, combine the& and! operators:

iris%>%select(starts_with("Petal")&!ends_with("Width"))#> # A tibble: 150 x 1#>   Petal.Length#>          <dbl>#> 1          1.4#> 2          1.4#> 3          1.3#> 4          1.5#> # i 146 more rows