Movatterモバイル変換

Class "CRS" of coordinate reference system arguments

Description

Interface class to the PROJ projection and transformation system. The class is defined as an empty stub accepting value NA in the sp package. The initiation function may call the PROJ library throughsf to verify the argument set against those known in the library, returning error messages where necessary. If the"CRS" object is instantiated usingCRS() withsf using PROJ >= 6 and GDAL >= 3, the object may also have a WKT2 (2019) string carried as acomment. The arguments for a Proj.4 string must be entered exactly as in the Proj.4 documentation, in particular there cannot be any white space in+<key>=<value> strings, and successive such strings can only be separated by blanks. Note that only “+proj=longlat +ellps=WGS84” is accepted for geographical coordinates, which must be ordered (eastings, northings); the “+ellps=” definition must be given (or expanded internally from a given “+datum=” value) for recent versions of the Proj.4 library, and should be set to an appropriate value.

Usage

CRS(projargs, doCheckCRSArgs=TRUE, SRS_string=NULL, get_source_if_boundcrs=TRUE, use_cache=TRUE)identicalCRS(x,y)

Arguments

Value

CRS returns on success an object of classCRS.identicalCRS returns a logical, indicatingwhetherx andy have identical CRS, or ifyis missing whether all objects in listxhave identical CRS.

Objects from the Class

Objects can be created by calls of the formCRS("projargs"), where "projargs" is a valid string of PROJ.4 arguments. If the argument is a zero-length string or a characterNA, the object recordsNA. If the"CRS" object is instantiated usingCRS() withsf using PROJ >= 6 and GDAL >= 3, the object may also have a WKT2 (2019) string carried as acomment. The initiation function may call the PROJ library throughsf to verify the argument set against those known in the library, returning error messages where necessary.

Slots

projargs:

Object of class"character": projection arguments; the arguments must be entered exactly as in the PROJ.4 documentation, in particular there cannot be any white space in +<arg>=<value> strings, and successive such strings can only be separated by blanks.

Methods

show

signature(object = "CRS"): print deprecated Proj.4 projection arguments and WKT2 2019 representation if available

wkt

signature(object = "CRS"): return WKT comment on object

rebuild_CRS

rebuild a CRS object, usually used to add a WKT comment with PROJ >= 6 and GDAL >= 3

Note

Lists of projections may be seen by using the programs installed with the PROJ.4 library, in particular proj and cs2cs; with the latter, -lp lists projections, -le ellipsoids, -lu units, and -ld datum(s) known to the installed software (available insf usingsf_proj_info). These are added to in successive releases, so tracking the website or compiling and installing the most recent revisions will give the greatest choice. Finding the very important datum transformation parameters to be given with the +towgs84 tag is a further challenge, and is essential when the datums used in data to be used together differ. Tracing projection arguments is easier now than before the mass ownership of GPS receivers raised the issue of matching coordinates from different argument sets (GPS output and paper map, for example). SeeGridsDatums,sf_proj_info for help in finding CRS definitions.

The 4.9.1 release of the PROJ library omitted a small file of defaults, leading to reports of “major axis or radius = 0 or not given” errors. From 0.9-3, rgdal checks for the presence of this file (proj_def.dat), and if not found, and under similar conditions to those used by PROJ.4, adds “+ellps=WGS84” to the input string being checked bycheckCRSArgs The “+no_defs” tag ignores the file of defaults, and the default work-around implemented to get around this problem; strings including “init” and “datum” tags also trigger the avoidance of the work-around. Now messages are issued when a candidate CRS is checked; they may be suppressed usingsuppressMessages.

From release 6 of the PROJ library, when used in buildingsf with GDAL >= 3, the+datum= key in the Proj.4 string CRS representation is deprecated, and the+towgs84= and+nadgrids= keys may be deprecated soon. For this reason,sp andsf are starting to use WKT2 (2019) string representations. Insp, the"CRS" object in itself remains unchanged, but the content of its"projargs" slot may be degraded. To work around the degradation, acomment is added around the"CRS" object containing a WKT2 (2019) string whensf is available and built with PROJ >= 6 and GDAL >=3.

Author(s)

Roger BivandRoger.Bivand@nhh.no

References

https://github.com/OSGeo/PROJ

Examples

CRS()CRS("")CRS(as.character(NA))CRS("+proj=longlat +datum=WGS84")run <- FALSErun <- require(sf) if (run) {  print((CRS("+proj=longlat +datum=NAD27")))}if (run) {  print((CRS("+init=epsg:4267")))}if (run) {  print((CRS("+init=epsg:26978")))}if (run) {  print((CRS(paste("+proj=sterea +lat_0=52.15616055555555", "+lon_0=5.38763888888889 +k=0.999908 +x_0=155000 +y_0=463000 +ellps=bessel", " +towgs84=565.237,50.0087,465.658,-0.406857,0.350733,-1.87035,4.0812 +units=m"))))}if (run) {  print((CRS("+init=epsg:28992")))}if (run) {  print((CRS("EPSG:28992")))}if (run) {  print((CRS(SRS_string="EPSG:28992")))}if (run) {  o <- try(CRS(SRS_string="ESRI:102760"))  if (!inherits(o, "try-error")) print((o))}if (run) {  o <- try(CRS("EPSG:4326"))  if (!inherits(o, "try-error")) print((o))}if (run) {  o <- try(CRS("ESRI:102760"))  if (!inherits(o, "try-error")) print((o))}if (run) {o <- new("Spatial")proj4string(o) <- CRS("+init=epsg:27700")}if (run && !is.null(comment(slot(o, "proj4string")))) {  cat(wkt(o), sep="\n")  cat(wkt(slot(o, "proj4string")), sep="\n")}

Class "DMS" for degree, minute, decimal second values

Description

The class provides a container for coordinates stored as degree, minute, decimal second values.

Objects from the Class

Objects can be created by calls of the formnew("DMS", ...), converted from decimal degrees usingdd2dms(), or converted from character strings usingchar2dms().

Slots

WS:

Object of class"logical" TRUE if input value negative

deg:

Object of class"numeric" degrees

min:

Object of class"numeric" minutes

sec:

Object of class"numeric" decimal seconds

NS:

Object of class"logical" TRUE if input value is a Northing

Methods

coerce

signature(from = "DMS", to = "numeric"): convert to decimal degrees

show

signature(object = "DMS"): print data values

Author(s)

Roger BivandRoger.Bivand@nhh.no

See Also

char2dms,dd2dms

Examples

data(state)dd2dms(state.center$x)dd2dms(state.center$y, NS=TRUE)as.numeric(dd2dms(state.center$y))as(dd2dms(state.center$y, NS=TRUE), "numeric")as.numeric.DMS(dd2dms(state.center$y))state.center$y

Class "GridTopology"

Description

class for defining a rectangular grid ofarbitrary dimension

Objects from the Class

Objects are created by using e.g.

GridTopology(c(0,0), c(1,1), c(5,5))

seeSpatialGrid

Slots

cellcentre.offset:

numeric; vector with the smallest centroid coordinates foreach dimension; coordinates refer to the cell centre

cellsize:

numeric; vector with the cell size in each dimension

cells.dim:

integer; vector with number of cells in each dimension

Methods

coordinates

signature(x = "SpatialGrid"): calculates coordinates foreach point on the grid

summary

signature(object = "SpatialGrid"): summarize object

coerce

signature(from = "GridTopology", to = "data.frame"): convert to data.frame with columns cellcentre.offset, cellsize and cells.dim

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

SpatialGridDataFrame-class,SpatialGrid-class

Examples

x = GridTopology(c(0,0), c(1,1), c(5,5))class(x)xsummary(x)coordinates(x)y = SpatialGrid(grid = x)class(y)y

Grids and Datums PE&RS listing

Description

A data.frame of years and months of Grids & Datums column publications by country and country code.

Usage

data("GridsDatums")

Format

A data frame with 241 observations on the following 4 variables.

country

name of PE&RS column

month

issue month

year

publication year

ISO

ISO code for country

Details

The journalPhotogrammetric Engineering & Remote Sensing, run by the American Society for Photogrammetry and Remote Sensing (ASPRS), began publishing a more-or-less monthly column on the spatial reference systems used in different countries, including their datums. The column first appeared in September 1997, and continued until March 2016; subsequent columns are updated reprints of previous ones. Some also cover other topics, such as world and Martian spatial reference systems. They are written by Clifford J. Mugnier, Louisiana State University, Fellow Emeritus ASPRS. To access the columns, visithttps:\/\/www.asprs.org/asprs-publications/grids-and-datums.

Source

https:\/\/www.asprs.org/asprs-publications/grids-and-datums

Examples

data(GridsDatums)GridsDatums[grep("Norway", GridsDatums$country),]GridsDatums[grep("Google", GridsDatums$country),]GridsDatums[grep("^Mars$", GridsDatums$country),]

create objects of class Line or Lines

Description

create objects of classLine orLines from coordinates

Usage

 Line(coords)Lines(slinelist, ID)

Arguments

Value

Line returns an object of classLine-class;Lines returns an object of classLines-class

See Also

SpatialLines-class

Examples

 # from the sp vignette:l1 = cbind(c(1,2,3),c(3,2,2))l1a = cbind(l1[,1]+.05,l1[,2]+.05)l2 = cbind(c(1,2,3),c(1,1.5,1))Sl1 = Line(l1)Sl1a = Line(l1a)Sl2 = Line(l2)S1 = Lines(list(Sl1, Sl1a),)S2 = Lines(list(Sl2),)

Class "Line"

Description

class for line objects

Objects from the Class

Objects can be created by calls of the formnew("Line", ...),or (preferred) by calls to the functionLine

Slots

coords:

Object of class"matrix", containing theline coordinates

Methods

coordinates

signature(obj = "Line"): retrieve coordinatesfrom line

lines

signature(x = "Line"): add lines to a plot

Author(s)

Roger Bivand, Edzer Pebesma

See Also

Lines-class,SpatialLines-class

Class "Lines"

Description

class for sets of line objects

Arguments

Objects from the Class

Objects can be created by calls to the functionLine

Slots

Lines:

Object of class"list", containing elementsof classLine-class

ID:

"character" vector of length one, with unique identifier string

Methods

coordinates

signature(obj = "Line"): retrieve coordinatesfrom lines; returns list with matrices

lines

signature(x = "Line"): add lines to a plot

Author(s)

Roger Bivand, Edzer Pebesma

See Also

Lines-class,SpatialLines-class

Class "Polygon"

Description

class for spatial polygon

Objects from the Class

Objects can be created by calls to the functionPolygon

Slots

ringDir:

Object of class"integer"; the ring direction of the ring (polygon) coordinates, holes are expected to be anti-clockwise

labpt:

Object of class"numeric"; an x, y coordinate pair forming the label point of the polygon

area:

Object of class"numeric"; the planar area of the polygon, does not respect projection as objects of this class have no projection defined

hole:

Object of class"logical"; does the polygon seem to be a hole

coords:

Object of class"matrix"; coordinates of the polygon;first point should equal the last point

Extends

Class"Line", directly.

Methods

No methods defined with class "Polygon" in the signature.

Author(s)

Roger Bivand

See Also

Polygons-class,SpatialPolygons-class

Class "Polygons"

Description

Collection of objects of class"Polygon"

Objects from the Class

Objects can be created by calls to the functionPolygons

Slots

Polygons:

Object of class"list"; list with objectsof classPolygon-class

plotOrder:

Object of class"integer"; order in whichthe Polygon objects should be plotted, currently by order of decreasing size

labpt:

Object of class"numeric"; pair of x, y coordinates giving a label point, the label point of the largest polygon component

ID:

Object of class"character"; unique identifier string

area:

Object of class"numeric"; the gross total planar area of the Polygon list but not double-counting holes (changed from 0.9-58 - islands are summed, holes are ignored rather than subtracted); these values are used to make sure that polygons of a smaller area are plotted after polygons of a larger area, does not respect projection as objects of this class have no projection defined

Methods

No methods defined with class "Polygons" in the signature.

Note

By default, single polygons (where Polygons is a list of length one) are not expected to be holes, but in multiple polygons, hole definitions for member polygons can be set. Polygon objects belonging to an Polygons object should either not overlap one-other, or should be fully included (as lakes or islands in lakes). They should not be self-intersecting. Checking of hole FALSE/TRUE status for Polygons objects is now handled by round-trip coercion tosf and back tosp.

Author(s)

Roger Bivand

Rlogo jpeg image

Description

Rlogo jpeg image data as imported bygetRasterData in the rgdal package

Usage

data(Rlogo)

Format

The format is:int [1:101, 1:77, 1:3] 255 255 255 255 255 255 255 255 255 255 ...

Examples

data(Rlogo)d = dim(Rlogo)cellsize = abs(c(gt[2],gt[6]))cells.dim = c(d[1], d[2]) # c(d[2],d[1])cellcentre.offset = c(x = gt[1] + 0.5 * cellsize[1], y = gt[4] - (d[2] - 0.5) * abs(cellsize[2]))grid = GridTopology(cellcentre.offset, cellsize, cells.dim)df = as.vector(Rlogo[,,1])for (band in 2:d[3]) df = cbind(df, as.vector(Rlogo[,,band]))df = as.data.frame(df)names(df) = paste("band", 1:d[3], sep="")Rlogo <- SpatialGridDataFrame(grid = grid, data = df)summary(Rlogo)spplot(Rlogo, zcol=1:3, names.attr=c("red","green","blue"), col.regions=grey(0:100/100),main="example of three-layer (RGB) raster image", as.table=TRUE)

Class "Spatial"

Description

An abstract class from which useful spatial classes arederived

Usage

Spatial(bbox, proj4string = CRS(as.character(NA)))## S3 method for class 'Spatial'subset(x, subset, select, drop = FALSE, ...)

Arguments

Objects from the Class

are never to be generated; only derived classes can be meaningful

Slots

bbox:

Object of class"matrix"; 2-column matrixholding the minimum in first and maximum in second column for thex-coordinate (first row), y-coordinate (second row) and optionally,for points and grids only, further coordinates. The constructed Spatial object will be invalid if any bbox values are NA or infinite. The column names must bec("min", "max")

proj4string:

Object of class"CRS". The name of this slot was chosen to reflect the use of Proj.4 strings to represent coordinate reference systems (CRS). The slot name will continue to be used, but as PROJ >= 6 and GDAL >= 3 are taken into use for reading files and for projection and transformation, the Proj.4 string CRS representation is being supplemented by a WKT2 (2019) representation. The reason for the modification is that important keys in the Proj.4 string representation are being deprecated in PROJ >= 6 and GDAL >= 3. Legacy"CRS" objects hold only a valid Proj.4 string, which can be used for unprojecting or reprojecting coordinates; it is initialised to NA. If the"CRS" object is instantiated usingCRS() withrgdal using PROJ >= 6 and GDAL >= 3, the object may also have a WKT2 (2019) string carried as acomment. Non-NA strings may be checked for validity in the rgdal package, but attempts to assign a string containing "longlat" to data extending beyond longitude [-180, 360] or lattitude [-90, 90] will be stopped or warned, useset_ll_warn to warn rather than stop, andset_ll_TOL to change the default tolerance for the range exceedance tests.

Methods

bbox

signature(obj = "Spatial"): retrieves the bbox element

dimensions

signature(obj = "Spatial"): retrieves the numberof spatial dimensions spanned

gridded

signature(obj = "Spatial"): logical, tells whetherthe data is on a regular spatial grid

plot

signature(x = "Spatial", y = "missing"): plot methodfor spatial objects; does nothing but setting up a plotting region choosinga suitable aspect if not given(see below), colouring the plot background using either a bg= argument or par("bg"), and possibly drawing axes.

summary

signature(object = "Spatial"): summarize object

$

retrieves attribute column

$<-

sets or replaces attribute column, or promote ageometry-only object to an object having an attribute

rebuild_CRS

rebuild a CRS object, usually used to add a WKT comment with PROJ >= 6 and GDAL >= 3

plot method arguments

The plot method for “Spatial” objects takes the following arguments:

x

object of class Spatial

xlim

default NULL; the x limits (x1, x2) of the plot

ylim

default NULL; the y limits of the plot

asp

default NA; the y/x aspect ratio

axes

default FALSE; a logical value indicating whether both axes should be drawn

bg

defaultpar("bg"); colour to be used for the background of the device region

xaxs

The style of axis interval calculation to be used for the x-axis

yaxs

The style of axis interval calculation to be used for the y-axis

lab

A numerical vector of the formc(x, y, len) which modifies the default way that axes are annotated

setParUsrBB

default FALSE; set thepar “usr” bounding box; see below

bgMap

object of classggmap, or returned by functionRgoogleMaps::GetMap

expandBB

numeric; factor to expand the plotting region default:bbox(x) with oneach side (1=below, 2=left, 3=above and 4=right); defaults toc(0,0,0,0); settingxlim orylim overrides this.

...

passed through

Warning

this class is not useful in itself, but all spatialclasses in this package derive from it

Note

The default aspect for map plots is 1; if however data are notprojected (coordinates are longlat), the aspect is by default set to1/cos(My * pi)/180) with My the y coordinate of the middle of the map(the mean of ylim, which defaults to the y range of bounding box).

The argumentsetParUsrBB may be used to pass the logical valueTRUE to functions withinplot.Spatial. When set toTRUE, par(“usr”) will be overwritten withc(xlim, ylim), which defaults to the bounding box of the spatial object. This is only needed in the particular context of graphic output to a specified device with given width and height, to be matched to the spatial object, when using par(“xaxs”) and par(“yaxs”) in addition topar(mar=c(0,0,0,0)).

Author(s)

r-spatial team; Edzer Pebesma,edzer.pebesma@uni-muenster.deRoger Bivand, Barry Rowlingson, Virgilio G\'omez-Rubio

See Also

SpatialPoints-class,SpatialGrid-class,SpatialPointsDataFrame-class,SpatialGridDataFrame-class

Examples

o <- new("Spatial")proj4string(o) <- CRS("+init=epsg:27700")if (!is.null(comment(slot(o, "proj4string")))) {  cat(strsplit(wkt(o), "\n")[[1]], sep="\n")  cat(strsplit(wkt(slot(o, "proj4string")), "\n")[[1]], sep="\n")}

Class "SpatialGrid"

Description

class for defining a full, rectangular grid ofarbitrary dimension

Objects from the Class

Objects are created by using e.g.

SpatialGrid(grid)

with grid of classGridTopology-class

Slots

grid

object of classGridTopology-class, defining thegrid topology (offset, cellsize, dim)

bbox:

Object of class"matrix"; bounding box

proj4string:

Object of class"CRS"; projection

Extends

Class"SpatialPoints" directly;Class"Spatial", by class"SpatialPoints".

Methods

coordinates

signature(x = "SpatialGrid"): calculates coordinates foreach point on the grid; coordinates are not stored in objects of class SpatialGrid

summary

signature(object = "SpatialGrid"): summarize object

plot

signature(x = "SpatialGrid"): plots cell centers

"["

signature(x = "SpatialGrid"): select rows and columns

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

SpatialGridDataFrame-class,SpatialGrid

Examples

x = GridTopology(c(0,0), c(1,1), c(5,5))class(x)xsummary(x)coordinates(x)y = SpatialGrid(grid = x)class(y)y

Class "SpatialGridDataFrame"

Description

Class for spatial attributes that have spatial locationson a (full) regular grid.

Objects from the Class

Objects can be created by calls of the formas(x,"SpatialGridDataFrame"), wherex is of classSpatialPixelsDataFrame-class, or by importing through rgdal. Ordered full grids are stored instead or unordered non-NA cells;

Slots

grid:

seeGridTopology-class; grid parameters

bbox:

Object of class"matrix"; bounding box

proj4string:

Object of class"CRS"; projection

data:

Object of class data.frame, containing attribute data

Extends

Class"SpatialGrid", directly.Class"Spatial", by class"SpatialGrid".

Methods

coordinates

signature(x = "SpatialGridDataFrame"): retrieves (and calculates!) coordinates

[

signature(x = "SpatialGridDataFrame"): selects rows, columns, and attributes; returns anobject of classSpatialGridDataFrame

as.matrix

signature(x = "SpatialGridDataFrame"): coerce to matrix; increasing col index corresponds to decreasing y coordinate, row index increases with coordinate index

as.array

signature(x = "SpatialGridDataFrame"): coerce to array; increasing array index for the second dimension corresponds to decreasing coordinates, all other coordinate dimensions increase with array index

cbind

signature(...): if arguments have identical topology, combine theirattribute values

Plot method arguments

The plot methods for “SpatialPixelsDataFrame” or “SpatialGridDataFrame” objects take the following arguments:

x

object of classSpatialPixelsDataFrame orSpatialGridDataFrame

...

arguments passed on toimage.SpatialGridDataFrame

attr

integer or character, indicating the attribute variable to be plotted; default 1

col

color ramp to be used; defaultbpy.colors(100) for continuous, orRColorBrewer::brewer.pal(nlevels(x[[1]]), "Set2") for factor variables

breaks

for continuous attributes: values at which color breaks should take place

zlim

for continuous attributes: numeric of length 2, specifying the range of attribute values to be plotted; default to data rangerange(as.numeric(x[[attr]])[is.finite(x[[attr]])])

axes

logical: draw x and y axes? defaultFALSE

xaxs

character, default "i", seepar

yaxs

character, default equal toxaxs, seepar

at

numeric or NULL, values at which axis tics and labels should be drawn; default NULL (usepretty)

border

color, to be used for drawing grid lines; default NA (don't draw grid lines)

axis.pos

integer, 1-4; default 4, seeaxis

add.axis

logical: draw axis along scale? defaultTRUE

what

what to draw:"image","scale", or"both"; default "both"

scale.size

size for the scale bar; uselcm to specify in absolute size, or a numericvalue such as1/6 to specify relative size; defaultlcm(2.8)

scale.shrink

non-negative numeric indicating the amount to shrink the scale length, default 0

scale.frac

for categorical attributes: numeric between 0 and 1, indicating the scale width, default 0.3

scale.n

for categorical attributes: integer, indicating how many scale categories should fill a complete width; default 15

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

SpatialGrid-class, which does not contain the attribute data,andSpatialPixelsDataFrame-class which holds possibly incomplete grids

Plotting gridded data with sp:https://r-spatial.org/r/2016/03/08/plotting-spatial-grids.html

Examples

data(meuse.grid) # only the non-missing valued cellscoordinates(meuse.grid) = c("x", "y") # promote to SpatialPointsDataFramegridded(meuse.grid) <- TRUE # promote to SpatialPixelsDataFramex = as(meuse.grid, "SpatialGridDataFrame") # creates the full gridx[["idist"]] = 1 - x[["dist"]] # assigns new attributeimage(x["idist"]) # note the single [ for attribute selection# toy example:df = data.frame(z = c(1:6,NA,8,9),    xc = c(1,1,1,2,2,2,3,3,3),    yc = c(rep(c(0, 1.5, 3),3)))coordinates(df) = ~xc+ycgridded(df) = TRUEdf = as(df, "SpatialGridDataFrame") # to full gridimage(df["z"])# draw labels to verify:cc = coordinates(df)z=df[["z"]]zc=as.character(z)zc[is.na(zc)]="NA"text(cc[,1],cc[,2],zc)# the following is weird, but illustrates the concept of row/col selection:fullgrid(meuse.grid) = TRUEimage(meuse.grid)image(meuse.grid[20:70, 10:70, "dist"], add = TRUE, col = bpy.colors())# as.matrix, as.arraysgdim = c(3,4)SG = SpatialGrid(GridTopology(rep(0,2), rep(10,2), sgdim))SGDF = SpatialGridDataFrame(SG, data.frame(val = 1:12))as.array(SGDF)as.matrix(SGDF)as(SGDF, "array")

create objects of class SpatialLines or SpatialLinesDataFrame

Description

create objects of classSpatialLines orSpatialLinesDataFrame fromlists ofLines objects and data.frames; extract list od Lines from a SpatialLines object

Usage

 SpatialLines(LinesList, proj4string = CRS(as.character(NA)))SpatialLinesDataFrame(sl, data, match.ID = TRUE)as.SpatialLines.SLDF(SLDF)getSpatialLinesMidPoints(SL)LineLength(cc, longlat = FALSE, sum = TRUE)LinesLength(Ls, longlat = FALSE)SpatialLinesLengths(SL, longlat)

Arguments

Value

SpatialLines returns object of classSpatialLines;SpatialLinesDataFrame returns object of classSpatialLinesDataFramegetSpatialLinesMidPoints returns an object of classSpatialPoints,each point containing the (weighted) mean of the lines elements; weighted in the sense that mean is called twice.

See Also

SpatialLines-class

a class for spatial lines

Description

a class that holds spatial lines

Objects from the Class

hold a list of Lines objects; each Lines object holds a listof Line (line) objects.

Slots

lines:

Object of class"list"; list members are all ofclassLines-class

bbox:

Object of class"matrix"; seeSpatial-class

proj4string:

Object of class"CRS"; seeCRS-class

Extends

Class"Spatial", directly.

Methods

[

signature(obj = "SpatialLines"): select subset of (sets of) lines; NAs are not permitted in the row index

coordinates

value is a list of lists with matrices

plot

signature(x = "SpatialLines", y = "missing"): plot lines in SpatialLines object

lines

signature(x = "SpatialLines"): add lines in SpatialLines object to a plot

rbind

signature(object = "SpatialLines"): rbind-like method, see notes

summary

signature(object = "SpatialLines"): summarize object

plot method arguments

The plot method for “SpatialLines” objects takes the following arguments:

x

object of class SpatialLines

xlim

default NULL; the x limits (x1, x2) of the plot

ylim

default NULL; the y limits of the plot

col

default 1; default plotting color

lwd

default 1; line width

lty

default 1; line type

add

default FALSE; add to existing plot

axes

default FALSE; a logical value indicating whether both axes should be drawn

lend

default 0; line end style

ljoin

default 0; line join style

lmitre

default 10; line mitre limit

...

passed through

setParUsrBB

set thepar “usr” bounding box, see note inSpatial-class

Note

rbind calls the functionSpatialLines, where it is checked that all IDs are unique. Ifrbind-ingSpatialLines without unique IDs, it is possible to set the argumentmakeUniqueIDs = TRUE, althoughit is preferred to change these explicitly withspChFIDs.

Author(s)

Roger Bivand, Edzer Pebesma

See Also

Line-class,Lines-class

Examples

 # from the sp vignette:l1 = cbind(c(1,2,3),c(3,2,2))rownames(l1) = letters[1:3]l1a = cbind(l1[,1]+.05,l1[,2]+.05)rownames(l1a) = letters[1:3]l2 = cbind(c(1,2,3),c(1,1.5,1))rownames(l2) = letters[1:3]Sl1 = Line(l1)Sl1a = Line(l1a)Sl2 = Line(l2)S1 = Lines(list(Sl1, Sl1a),)S2 = Lines(list(Sl2),)Sl = SpatialLines(list(S1,S2))summary(Sl)plot(Sl, col = c("red", "blue"))

a class for spatial lines with attributes

Description

this class holds data consisting of (sets of lines), where eachset of lines relates to an attribute row in a data.frame

Objects from the Class

can be created by the functionSpatialLinesDataFrame

Slots

data:

Object of classdata.frame containing the attribute table

lines:

Object of class"list"; seeSpatialLines-class

bbox:

Object of class"matrix"; seeSpatial-class

proj4string:

Object of class"CRS"; seeCRS-class

Extends

Class"SpatialLines", directly.Class"Spatial", by class"SpatialLines".

Methods

Methods defined with class "SpatialLinesDataFrame" in the signature:

[

signature(x = "SpatialLinesDataFrame"): subset rows orcolumns; in case of row subsetting, the line sets are also subsetted; NAs are not permitted in the row index

coordinates

signature(obj = "SpatialLinesDataFrame"): retrievesa list with lists of coordinate matrices

show

signature(object = "SpatialLinesDataFrame"): print method

plot

signature(x = "SpatialLinesDataFrame"): plot points

lines

signature(object = "SpatialLinesDataFrame"): add lines to plot

rbind

signature(object = "SpatialLinesDataFrame"): rbind-like method

Note

rbind forSpatialLinesDataFrame is only possible for objects with unique IDs. If you want torbind objectswith duplicated IDs, seespChFIDs.

Author(s)

Roger Bivand; Edzer Pebesma

See Also

SpatialLines-class

create objects of class SpatialMultiPoints or SpatialMultiPointsDataFrame

Description

create objects of classSpatialMultiPoints-class orSpatialMultiPointsDataFrame-class fromcoordinates, and from coordinates anddata.frames

Usage

 SpatialMultiPoints(coords, proj4string=CRS(as.character(NA)), bbox = NULL)SpatialMultiPointsDataFrame(coords, data,      proj4string = CRS(as.character(NA)), match.ID, bbox = NULL)

Arguments

Value

SpatialMultiPoints returns an object of classSpatialMultiPoints;SpatialMultiPointsDataFrame returns an object of classSpatialMultiPointsDataFrame;

See Also

coordinates,SpatialMultiPoints-class,SpatialMultiPointsDataFrame-class

Examples

cl1 = cbind(rnorm(3, 10), rnorm(3, 10))cl2 = cbind(rnorm(5, 10), rnorm(5,  0))cl3 = cbind(rnorm(7,  0), rnorm(7, 10))mp = SpatialMultiPoints(list(cl1, cl2, cl3))mpx = rbind(mp, mp) # rbind methodplot(mp, col = 2, cex = 1, pch = 1:3)mpmp[1:2]print(mp, asWKT=TRUE, digits=3)mpdf = SpatialMultiPointsDataFrame(list(cl1, cl2, cl3), data.frame(a = 1:3))mpdfmpdfx = rbind(mpdf, mpdf) # rbind methodplot(mpdf, col = mpdf$a, cex = 1:3)as(mpdf, "data.frame")mpdf[1:2,]

Class "SpatialMultiPoints"

Description

Class for (irregularly spaced) MultiPoints

Objects from the Class

Objects can be created by calls of the formSpatialPoints(x).

Slots

coords:

Object of class"list", containing thecoordinates of point sets (each list element is a matrix)

bbox:

Object of class"matrix", with bounding box

proj4string:

Object of class"CRS", projection string

Extends

Class"Spatial", directly.

Methods

[

signature(x = "SpatialMultiPoints"): subsets point sets

coerce

signature(from = "SpatialPoints", to = "data.frame"): coerce to data.frame

coordinates

signature(obj = "SpatialMultiPoints"): retrievesall the coordinates, as one single matrix

plot

signature(x = "SpatialPoints", y = "missing"): plot points

summary

signature(object = "SpatialPoints"): summarize object

points

signature(x = "SpatialPoints"): add point symbols to plot

show

signature(object = "SpatialPoints"): prints coordinates

rbind

signature(object = "SpatialPoints"): rbind-like method

plot method arguments

The plot method for “SpatialPoints” objects takes the following arguments:

x

object of class SpatialPoints

pch

default 3; either an integer specifying a symbol or a single character to be used as the default in plotting points

axes

default FALSE; a logical value indicating whether both axes should be drawn

add

default FALSE; add to existing plot

xlim

default NULL; the x limits (x1, x2) of the plot

ylim

default NULL; the y limits of the plot

...

passed through

setParUsrBB

default FALSE; set thepar “usr” bounding box, see note inSpatial-class

cex

default 1; numerical value giving the amount by which plotting text and symbols should be magnified relative to the default

col

default 1; default plotting color

lwd

default 1; line width

bg

default 1; colour to be used for the background of the device region

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

SpatialMultiPointsDataFrame-classSpatialPoints-class

Examples

cl1 = cbind(rnorm(3, 10), rnorm(3, 10))cl2 = cbind(rnorm(5, 10), rnorm(5,  0))cl3 = cbind(rnorm(7,  0), rnorm(7, 10))mp = SpatialMultiPoints(list(cl1, cl2, cl3))plot(mp, col = 2, cex = 1, pch = 1:3)mpmp[1:2]print(mp, asWKT=TRUE, digits=3)

Class "SpatialMultiPointsDataFrame"

Description

Class for spatial attributes that correspond to point sets

Usage

  ## S4 method for signature 'SpatialMultiPointsDataFrame'x[i, j, ..., drop = TRUE]  ## S4 method for signature 'SpatialMultiPointsDataFrame,data.frame'coerce(from, to, strict=TRUE)  ## S4 method for signature 'SpatialMultiPointsDataFrame'coordinates(obj)  ## S4 method for signature 'SpatialMultiPointsDataFrame'show(object)  ## S4 method for signature 'SpatialMultiPointsDataFrame'points(x)

Arguments

Slots

data:

Object of class data.frame containingthe attribute data (may or may not contain the coordinates in its columns)

coords:

Object of class"list"; the list with coordinates matrices;points are rows in the matrix, the list length equals the number of rows in thedata slot

bbox:

Object of class"matrix"; bounding box

proj4string:

Object of class"CRS"; projection string

Extends

Class"SpatialMultiPoints", directly.Class"Spatial", by class"SpatialMultiPoints".

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

coordinates,SpatialMultiPoints-class

Examples

# create three sets of points:cl1 = cbind(rnorm(3, 10), rnorm(3, 10))cl2 = cbind(rnorm(5, 10), rnorm(5,  0))cl3 = cbind(rnorm(7,  0), rnorm(7, 10))mpdf = SpatialMultiPointsDataFrame(list(cl1, cl2, cl3), data.frame(a = 1:3))mpdfplot(mpdf, col = mpdf$a, cex = 1:3)as(mpdf, "data.frame")mpdf[1:2,]

define spatial grid

Description

defines spatial grid by offset, cell size and dimensions

Usage

GridTopology(cellcentre.offset, cellsize, cells.dim)SpatialPixels(points, tolerance = sqrt(.Machine$double.eps),proj4string = CRS(as.character(NA)), round = NULL, grid = NULL)SpatialGrid(grid, proj4string = CRS(as.character(NA)))coordinatevalues(obj)points2grid(points, tolerance = sqrt(.Machine$double.eps), round=NULL)getGridIndex(cc, grid, all.inside = TRUE)getGridTopology(obj)areaSpatialGrid(obj)

Arguments

Value

GridTopology returns a value of classGridTopology-class;SpatialGrid returns an object of classSpatialGrid-class

coordinatevalues returns a list with the unique x-coordinates,the unique y-coordinate, etc. instead of thecoordinates of allgrid cells

SpatialGrid returns an object of classSpatialGrid-class.

points2grid returns theGridTopology-class from a set of points.

getGridIndex finds the index of a set of point coordinates in a givengrid topology, and depending onall.inside setting, generates NAor an error message if points are outside the grid domain.

getGridTopology returns the slot of classGridTopology-class fromobj.

areaSpatialGrid returns the spatial area of (the non-missing valued cellsof) the grid. For objects of classSpatialGridDataFrame-classthe area refers to cells where any (one or more) of the attribute columnsare non-missing valued.

Note

SpatialGrid stores grid topology and may or may not store the coordinatesof the actual points, which may form a subset of the full grid. To findout or change this, seefullgrid.

points2grid tries to figure out the grid topology from points. It succeedsonly if points on a grid line have constant y column, and points on agrid column have constant x coordinate, etc. In other cases, use signifon the raw coordinate matrices to make sure this is the case.

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

SpatialGrid-class,SpatialGridDataFrame-class,

Examples

x = GridTopology(c(0,0), c(1,1), c(5,4))class(x)xsummary(x)coordinates(x)coordinates(GridTopology(c(0,0), c(1,1), c(5,4)))coordinatevalues(x)data(meuse.grid)coordinates(meuse.grid) <- c("x", "y")points2grid(meuse.grid)data(meuse.grid)set.seed(1)meuse.grid$x <- meuse.grid$x + rnorm(length(meuse.grid$x), 0, 0.002)meuse.grid$y <- meuse.grid$y + rnorm(length(meuse.grid$y), 0, 0.002)coordinates(meuse.grid) <- c("x", "y")#EJP# points2grid(meuse.grid, tolerance=0.76, round=1)data(meuse.grid)a <- which(meuse.grid$x == 180140)b <- which(meuse.grid$x == 180180)c <- which(meuse.grid$x == 179260)d <- which(meuse.grid$y == 332460)e <- which(meuse.grid$y == 332420)f <- which(meuse.grid$y == 330740)meuse.grid <- meuse.grid[-c(a, b, c, d, e, f),]coordinates(meuse.grid) <- c("x", "y")points2grid(meuse.grid)data(meuse.grid)set.seed(1)meuse.grid$x <- meuse.grid$x + rnorm(length(meuse.grid$x), 0, 0.002)meuse.grid$y <- meuse.grid$y + rnorm(length(meuse.grid$y), 0, 0.002)meuse.grid <- meuse.grid[-c(a, b, c, d, e, f),]coordinates(meuse.grid) <- c("x", "y")# EJP# points2grid(meuse.grid, tolerance=0.69, round=1)

Class "SpatialPixels"

Description

class for defining a pixels, forming apossibly incomplete rectangular grid of arbitrary dimension

Objects from the Class

Objects are created by using e.g.

SpatialPixels(points)

with points of classSpatialPoints-class

Slots

grid

object of classGridTopology-class, defining thegrid topology (offset, cellsize, dim)

grid.index

integer; index of points in full grid

coords

coordinates of points, or bbox of grid

bbox:

Object of class"matrix"; bounding box

proj4string:

Object of class"CRS"; projection

Extends

Class"SpatialPoints" directly;Class"Spatial", by class"SpatialPoints".

Methods

coordinates

signature(x = "SpatialPixels"): calculates coordinates foreach point on the grid; coordinates are not stored in objects of class SpatialGrid

summary

signature(object = "SpatialPixels"): summarize object

plot

signature(x = "SpatialPixels"): plots cell centers

"["

signature(x = "SpatialPixels"): select pixel cells; the argumentdrop=FALSE (default) does not recalculate grid topology for the selection, ifdrop=TRUE the grid topology is recomputed, and might change.

rbind

signature(x = "SpatialPixels"): rbind-like method

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

SpatialPixelsDataFrame-class,SpatialGrid-class

Examples

data(meuse.grid)pts = meuse.grid[c("x", "y")]y = SpatialPixels(SpatialPoints(pts))class(y)ysummary(y)plot(y) # plots gridplot(y, grid = FALSE) # plots points

define spatial grid with attribute data

Description

defines spatial grid by offset, cell size and dimensions

Usage

SpatialPixelsDataFrame(points, data, tolerance = sqrt(.Machine$double.eps), proj4string = CRS(as.character(NA)), round = NULL, grid = NULL)SpatialGridDataFrame(grid, data, proj4string = CRS(as.character(NA)))

Arguments

Value

SpatialPixelsDataFrame returns an object of classSpatialPixelsDataFrame-class; SpatialGridDataFrame returns an objectof classSpatialGridDataFrame-class.

Note

SpatialPixels stores grid topology and coordinates of the actual points,which may be in the form of a subset (set of pixels) of a full grid. Tofind out or change this, seefullgrid andSpatialGrid-class.

Author(s)

Edzer Pebesma

See Also

gridded,gridded<-,SpatialGrid,SpatialGrid-class

Examples

data(meuse.grid)m = SpatialPixelsDataFrame(points = meuse.grid[c("x", "y")], data = meuse.grid)class(m)summary(m)

Class "SpatialPixelsDataFrame"

Description

Class for spatial attributes that have spatial locationson a regular grid.

Objects from the Class

Objects can be created by calls of the formas(x,"SpatialPixelsDataFrame"), wherex is of classSpatialPointsDataFrame-class, or by importing through rgdal. Ordered full grids are stored instead or unordered non-NA cells;

Slots

bbox:

Object of class"matrix"; bounding box

proj4string:

Object of class"CRS"; projection

coords:

seeSpatialPoints; points slot

coords.nrs

seeSpatialPointsDataFrame

grid:

seeGridTopology-class; grid parameters

grid.index:

integer; index of points in the list to pointsin the full (ordered) grid. x cycles fastest; all coordinates increasefrom low to hight except y, which decreases from high to low

data:

Object of class data.frame, containing the attribute data

Extends

Class"SpatialPixels", directly.Class"Spatial", by class"SpatialPixels".

Methods

coordinates

signature(x = "SpatialPixelsDataFrame"): retrieves coordinates

[

signature(x = "SpatialPixelsDataFrame"): selects row(s) and/or attribute(s), and returns anobject of classSpatialPixelsDataFrame; rows refer here to the pixelnumbers, not grid lines. For selecting a square block in a grid, coerce toaSpatialGridDataFrame-class first, and use[ on that object

as.matrix

signature(x = "SpatialPixelsDataFrame"): coerce to matrix

rbind

signature(x = "SpatialPixelsDataFrame"): rbind-like method

plot

signature(x = "SpatialPixelsDataFrame", y = "missing"): seeSpatialGridDataFrame-class for details

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

SpatialPixels-class, which does not contain the attribute data

Examples

data(meuse.grid) # only the non-missing valued cellscoordinates(meuse.grid) = c("x", "y") # promote to SpatialPointsDataFramegridded(meuse.grid) <- TRUE # promote to SpatialPixelsDataFramemeuse.grid[["idist"]] = 1 - meuse.grid[["dist"]] # assigns new attributeimage(meuse.grid["idist"]) # note the single [# toy example:df = data.frame(z = c(1:6,NA,8,9),    xc = c(1,1,1,2,2,2,3,3,3),    yc = c(rep(c(0, 1.5, 3),3)))coordinates(df) = ~xc+ycgridded(df) = TRUEimage(df["z"])# draw labels to verify:cc = coordinates(df)z=df[["z"]]zc=as.character(z)zc[is.na(zc)]="NA"text(cc[,1],cc[,2],zc)

create objects of class SpatialPoints or SpatialPointsDataFrame

Description

create objects of classSpatialPoints-class orSpatialPointsDataFrame-class fromcoordinates, and from coordinates anddata.frames

Usage

 SpatialPoints(coords, proj4string=CRS(as.character(NA)), bbox = NULL)SpatialPointsDataFrame(coords, data, coords.nrs = numeric(0),       proj4string = CRS(as.character(NA)), match.ID, bbox = NULL)

Arguments

Value

SpatialPoints returns an object of classSpatialPoints;SpatialPointsDataFrame returns an object of classSpatialPointsDataFrame;

See Also

coordinates,SpatialPoints-class,SpatialPointsDataFrame-class

Examples

set.seed(1331)pts = cbind(1:5, 1:5)dimnames(pts)[[1]] = letters[1:5]df = data.frame(a = 1:5)row.names(df) = letters[5:1]library(sp)options(warn=1) # show warnings where they occurSpatialPointsDataFrame(pts, df) # warnSpatialPointsDataFrame(pts, df, match.ID = TRUE) # don't warnSpatialPointsDataFrame(pts, df, match.ID = FALSE) # don't warndf$m = letters[5:1]SpatialPointsDataFrame(pts, df, match.ID = "m") # don't warndimnames(pts)[[1]] = letters[5:1]SpatialPointsDataFrame(pts, df) # don't warn: ID matching doesn't reorder

Class "SpatialPoints"

Description

Class for (irregularly spaced) points

Objects from the Class

Objects can be created by calls of the formSpatialPoints(x).

Slots

coords:

Object of class"matrix", containing thecoordinates (each row is a point)

bbox:

Object of class"matrix", with bounding box

proj4string:

Object of class"CRS", projection string

Extends

Class"Spatial", directly.

Methods

[

signature(x = "SpatialPoints"): subsets the points; onlyrows (points) can be subsetted

coerce

signature(from = "SpatialPoints", to = "data.frame"): retrieves the data part

coerce

signature(from = "SpatialPoints", to = "SpatialPixels"): equivalent to assigning gridded TRUE for a copy of the object

coerce

signature(from = "SpatialPointsDataFrame", to = "SpatialPixelsDataFrame"): equivalent to assigning gridded TRUE for a copy of the object

coerce

signature(from = "data.frame", to = "SpatialPoints"): setscoordinates, which may be in a data frame

coerce

signature(from = "matrix", to = "SpatialPoints"): setcoordinates, which may be in a matrix

coordinates

signature(obj = "SpatialPoints"): retrievesthe coordinates, as matrix

plot

signature(x = "SpatialPoints", y = "missing"): plot points

summary

signature(object = "SpatialPoints"): summarize object

points

signature(x = "SpatialPoints"): add point symbols to plot

show

signature(object = "SpatialPoints"): prints coordinates

rbind

signature(object = "SpatialPoints"): rbind-like method

plot method arguments

The plot method for “SpatialPoints” objects takes the following arguments:

x

object of class SpatialPoints

pch

default 3; either an integer specifying a symbol or a single character to be used as the default in plotting points

axes

default FALSE; a logical value indicating whether both axes should be drawn

add

default FALSE; add to existing plot

xlim

default NULL; the x limits (x1, x2) of the plot

ylim

default NULL; the y limits of the plot

...

passed through

setParUsrBB

default FALSE; set thepar “usr” bounding box, see note inSpatial-class

cex

default 1; numerical value giving the amount by which plotting text and symbols should be magnified relative to the default

col

default 1; default plotting color

lwd

default 1; line width

bg

default 1; colour to be used for the background of the device region

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

SpatialPointsDataFrame-class

Examples

x = c(1,2,3,4,5)y = c(3,2,5,1,4)S <- SpatialPoints(cbind(x,y))S <- SpatialPoints(list(x,y))S <- SpatialPoints(data.frame(x,y))Splot(S)

Class "SpatialPointsDataFrame"

Description

Class for spatial attributes that have spatial point locations

Usage

  ## S4 method for signature 'SpatialPointsDataFrame'x[i, j, ..., drop = TRUE]  ## S4 method for signature 'SpatialPointsDataFrame,SpatialPoints'coerce(from, to, strict=TRUE)  ## S4 method for signature 'SpatialPointsDataFrame,data.frame'coerce(from, to, strict=TRUE)  ## S4 method for signature 'SpatialPointsDataFrame'coordinates(obj)  ## S4 method for signature 'SpatialPointsDataFrame'show(object)  ## S4 method for signature 'SpatialPointsDataFrame'points(x)  ## S3 method for class 'SpatialPointsDataFrame'rbind(...)

Arguments

Objects from the Class

Objects can be created by calls of the formcoordinates(x) = c("x", "y").or of the formcoordinates(x) = xy; seecoordinates.

Slots

data:

Object of class data.frame containingthe attribute data (may or may not contain the coordinates in its columns)

coords:

Object of class"matrix"; the coordinates matrix(points are rows in the matrix)

coords.nrs

Object of class logical; if TRUE, whenthe object was created the coordinates were retrieved from the data.frame,and hence stripped from it; after coercion to data.frame, e.g. by as.data.frame(x), coordinates will again be added (as first few columns) to the data.frame

bbox:

Object of class"matrix"; bounding box

proj4string:

Object of class"CRS"; projection string

Extends

Class"SpatialPoints", directly.Class"Spatial", by class"SpatialPoints".

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

coordinates,SpatialPoints-class

Examples

data(meuse)xy = meuse[c("x", "y")] # retrieve coordinates as data.frameclass(meuse)data(meuse) # reload data.framecoordinates(meuse) = c("x", "y") # specify column namesclass(meuse)data(meuse) # reload data.framecoordinates(meuse) = c(1, 2) # specify column namesclass(meuse)data(meuse) # reload data.framecoordinates(meuse) = ~x+y # formulaclass(meuse)data(meuse) # reload data.framecoordinates(meuse) = xy   # as data frameclass(meuse)data(meuse) # reload data.framecoordinates(meuse) = as.matrix(xy)   # as matrixmeuse$log.zn = log(meuse$zinc)class(meuse)dim(meuse)

create objects of class SpatialPolygons or SpatialPolygonsDataFrame

Description

create objects of classSpatialPolygons orSpatialPolygonsDataFrame fromlists ofPolygons objects anddata.frames

Usage

 Polygon(coords, hole=as.logical(NA))Polygons(srl, ID)SpatialPolygons(Srl, pO, proj4string=CRS(as.character(NA)))SpatialPolygonsDataFrame(Sr, data, match.ID = TRUE)getSpatialPolygonsLabelPoints(SP)

Arguments

Details

InPolygon, if the hole argument is not given, the status of the polygon as a hole or an island will be taken from the ring direction, with clockwise meaning island, and counter-clockwise meaning hole. InPolygons, if all of the member Polygon objects are holes, the largest by area will be converted to island status. Until 2010-04-17, version 0.9-61, the area of this converted object was erroneously left at its hole value of zero. Thanks to Patrick Giraudoux for spotting the bug.

The class definitions used for polygons insp do not accord with those ofthe simple features specification of the Open Geospatial Consortium. Thergeos package, an interface to Geometry Engine – Open Source (GEOS), uses thisspecification, in which each hole (interior ring) must be associated withits containing exterior ring. In order to avoid introducing incompatiblechanges into the class definition of Polygons objects, a comment has beenadded as a single character string to each such object. Here we can trustthe data source to assign the hole status correctly, and use round-trip coercion tosf to add such comments to each Polygons member of the polygons slot of this SpatialPolygons object. Exterior rings are codedzero, while interior rings are coded with the 1-based index of theexterior ring to which they belong. SpatialPolygons objects created by reading usingsf have the comments set on input, as OGR also uses SFS.

Refer to Bivand et al. (2013), pages 47-48 and 132-133 for a further discussion.

Value

Polygon returns an object of classPolygon;Polygons returns an object of classPolygons;SpatialPolygons returns object of classSpatialPolygons;SpatialPolygonsDataFrame returns object of classSpatialPolygonsDataFramegetSpatialPolygonsLabelPoints returns an object of classSpatialPoints with label points.

References

Roger Bivand, Edzer Pebesma and Virgilio Gomez-Rubio, 2013. Applied spatial data analysis with R, Second edition. Springer, NY.https://asdar-book.org/

See Also

SpatialPolygons-class,SpatialPolygonsDataFrame-class

Class "SpatialPolygons"

Description

class to hold polygon topology (without attributes)

Objects from the Class

Objects can be created by calls to the functionSpatialPolygons

Slots

polygons:

Object of class"list"; list elements areall of classPolygons-class

plotOrder:

Object of class"integer"; integer arraygiving the order in which objects should be plotted

bbox:

Object of class"matrix"; seeSpatial-class

proj4string:

Object of class"CRS"; seeCRS-class

Extends

Class"Spatial", directly.

Methods

Methods defined with class "SpatialPolygons" in the signature:

[

signature(obj = "SpatialPolygons"): select subset of (sets of) polygons; NAs are not permitted in the row index

plot

signature(x = "SpatialPolygons", y = "missing"): plot polygons in SpatialPolygons object

summary

signature(object = "SpatialPolygons"): summarize object

rbind

signature(object = "SpatialPolygons"): rbind-like method

plot method arguments

Theplot method for spatial polygons takes the following arguments:

x

a SpatialPolygons object

col

a vector of colour values

border

defaultpar("fg"); the colour to draw the border

add

default FALSE; if TRUE, add to existing plot

xlim, ylim

default NULL; ranges for the plotted ‘x’ and ‘y’ values

xpd

default NULL; controls clipping, seepar

density

default NULL; the density of shading lines, in lines per inch, seepolygon

angle

default 45; the slope of shading lines, given as an angle in degrees (counter-clockwise), seepolygon

pbg

default NULL, set topar("bg") by default “transparent”; the colour to paint holes

axes

default FALSE; draw axes

lty

defaultpar("lty"); border line type

...

other arguments passed through

setParUsrBB

default FALSE; seeSpatial-class for further details

usePolypath

default NULL to set from option value; usepolypath for hole-handling in plot

rule

default NULL to set from option value; character value specifying the path fill mode, seepolypath

The options forusePolypath andrule may be retrieved withget_Polypath (default TRUE on package load) andget_PolypathRule (default “winding” on package load), and set withset_Polypath andset_PolypathRule

The class definitions used for polygons insp do not accord with those ofthe simple features specification of the Open Geospatial Consortium. Thergeos package, an interface to Geometry Engine – Open Source (GEOS), uses thisspecification, in which each hole (interior ring) must be associated withits containing exterior ring. In order to avoid introducing incompatiblechanges into the class definition of Polygons objects, a comment has beenadded as a single character string to each such object. Here we can trustthe data source to assign the hole status correctly, and use round-trip coercion tosf to add such comments to each Polygons member of the polygons slot of this SpatialPolygons object. Exterior rings are codedzero, while interior rings are coded with the 1-based index of theexterior ring to which they belong. SpatialPolygons objects created by reading usingsf orterra have the comments set on input, as OGR also uses SFS.

Refer to Bivand et al. (2013), pages 47-48 and 132-133 for a further discussion.

Note

rbind calls the functionSpatialPolygons, where it is checked that all IDs are unique. Ifrbind-ingSpatialPolygons without unique IDs, it is possible to set the argumentmakeUniqueIDs = TRUE, althoughit is preferred to change these explicitly withspChFIDs.

Author(s)

Roger Bivand

References

Roger Bivand, Edzer Pebesma and Virgilio Gomez-Rubio, 2013. Applied spatial data analysis with R, Second edition. Springer, NY.https://asdar-book.org/

See Also

SpatialPolygons

Examples

# simple example, from vignette("sp"):Sr1 = Polygon(cbind(c(2,4,4,1,2),c(2,3,5,4,2)))Sr2 = Polygon(cbind(c(5,4,2,5),c(2,3,2,2)))Sr3 = Polygon(cbind(c(4,4,5,10,4),c(5,3,2,5,5)))Sr4 = Polygon(cbind(c(5,6,6,5,5),c(4,4,3,3,4)), hole = TRUE)Srs1 = Polygons(list(Sr1), "s1")Srs2 = Polygons(list(Sr2), "s2")Srs3 = Polygons(list(Sr3, Sr4), "s3/4")SpP = SpatialPolygons(list(Srs1,Srs2,Srs3), 1:3)plot(SpP, col = 1:3, pbg="white")grd <- GridTopology(c(1,1), c(1,1), c(10,10))polys <- as(grd, "SpatialPolygons")plot(polys)text(coordinates(polys), labels=row.names(polys))

Class "SpatialPolygonsDataFrame"

Description

class to hold polygons with attributes

Objects from the Class

Objects can be created by calls to the functionSpatialPolygonsDataFrame

Slots

data:

Object of class"data.frame"; attribute table

polygons:

Object of class"list"; seeSpatialPolygons-class

plotOrder:

Object of class"integer"; seeSpatialPolygons-class

bbox:

Object of class"matrix"; seeSpatial-class

proj4string:

Object of class"CRS"; seeCRS-class

Extends

Class"SpatialPolygons", directly.Class"Spatial", by class"SpatialPolygons".

Methods

Methods defined with class "SpatialPolygonsDataFrame" in the signature:

[

signature(x = "SpatialPolygonsDataFrame"): select subset of (sets of) polygons; NAs are not permitted in the row index

rbind

signature(object = "SpatialPolygonsDataFrame"): rbind-like method, see notes below

Note

SpatialPolygonsDataFrame with default ID matching checks the data frame row names against the Polygons ID slots. They must then agree with each other, and be unique (no Polygons objects can share IDs); the data frame rows will be re-ordered if needed to match the Polygons IDs..

If you want torbind objects with duplicated IDs, seespChFIDs.

Author(s)

Roger Bivand

See Also

SpatialPolygons-class

Examples

# simple example, from scratch:Sr1 = Polygon(cbind(c(2,4,4,1,2),c(2,3,5,4,2)))Sr2 = Polygon(cbind(c(5,4,2,5),c(2,3,2,2)))Sr3 = Polygon(cbind(c(4,4,5,10,4),c(5,3,2,5,5)))Sr4 = Polygon(cbind(c(5,6,6,5,5),c(4,4,3,3,4)), hole = TRUE)Srs1 = Polygons(list(Sr1), "s1")Srs2 = Polygons(list(Sr2), "s2")Srs3 = Polygons(list(Sr3, Sr4), "s3/4")SpP = SpatialPolygons(list(Srs1,Srs2,Srs3), 1:3)plot(SpP, col = 1:3, pbg="white")grd <- GridTopology(c(1,1), c(1,1), c(10,10))polys <- as(grd, "SpatialPolygons")centroids <- coordinates(polys)x <- centroids[,1]y <- centroids[,2]z <- 1.4 + 0.1*x + 0.2*y + 0.002*x*xex_1.7 <- SpatialPolygonsDataFrame(polys, data=data.frame(x=x, y=y, z=z, row.names=row.names(polys)))brks <- quantile(z, seq(0,1,1/7))cols <- grey((length(brks):2)/length(brks))dens <- (2:length(brks))*3plot(ex_1.7, col=cols[findInterval(z, brks, all.inside=TRUE)])plot(ex_1.7, density=dens[findInterval(z, brks, all.inside=TRUE)])

constructs SpatialXxxDataFrame from geometry and attributes

Description

constructs SpatialXxxDataFrame from geometry and attributes

Usage

addAttrToGeom(x, y, match.ID, ...)

Arguments

Value

an object of class XxxDataFrame, where Xxx is the class of x

Methods

x = "SpatialPoints", y = "data.frame"

x = "SpatialPixels", y = "data.frame"

x = "SpatialGrid", y = "data.frame"

x = "SpatialLines", y = "data.frame"

x = "SpatialPolygons", y = "data.frame"

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

over

aggregation of spatial objects

Description

spatial aggregation of thematic information in spatial objects

Usage

## S3 method for class 'Spatial'aggregate(x, by = list(ID = rep(1, length(x))),FUN, ..., dissolve = TRUE, areaWeighted = FALSE)

Arguments

Details

For as far as these functions use package rgeos, (lines, polygons,dissolve = TRUE), they are deprecated as rgeos will retire; tryusing sf::aggregate instead.

FUN should be a function that takes as first argument avector, and that returns a single number. The canonical examplesaremean andsum. Counting features is obtained whensumming an attribute variable that has the value 1 everywhere.

Value

The aggregation of attribute values ofx either over thegeometry ofby by usingover for spatial matching,or by attribute values, using aggregation functionFUN.

IfareaWeighted isTRUE,FUN is ignored and thearea weighted mean is computed for numerical variables, or if allattributes arefactors, the area dominant factor level (areamode) is returned. This computes the intersection ofxandby; see examples below. As this uses code from packagergeos, it is deprecated as package rgeos will retire.

Ifby is missing, aggregates over all features.

Note

usesover to find spatial match ifby is aSpatial object

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

Examples

data("meuse")coordinates(meuse) <- ~x+ydata("meuse.grid")coordinates(meuse.grid) <- ~x+ygridded(meuse.grid) <- TRUEi = cut(meuse.grid$dist, c(0,.25,.5,.75,1), include.lowest = TRUE)j = sample(1:2, 3103,replace=TRUE)x = aggregate(meuse.grid["dist"], list(i=i,j=j), mean, dissolve = FALSE)spplot(x["j"], col.regions=bpy.colors())

Make SpatialPolygons object from GridTopology object

Description

Converts grids of regular rectangles into aSpatialPolygons object, which can be transformed to a different projection or datum withspTransform in packagergdal. The function is not suitable for high-resolution grids. The ordering of the grid cells is as incoordinates() of the same object, and is reported byIDvaluesGridTopology.

Usage

as.SpatialPolygons.GridTopology(grd, proj4string = CRS(as.character(NA)))IDvaluesGridTopology(obj)as.SpatialPolygons.SpatialPixels(obj)IDvaluesSpatialPixels(obj)HexPoints2SpatialPolygons(hex, dx)

Arguments

Value

as.SpatialPolygons.GridTopology andas.SpatialPolygons.SpatialPixels return aSpatialPolygons object;IDvaluesGridTopology andIDvaluesSpatialPixels return a character vector with the object grid indices.

See Also

GridTopology,SpatialPixels,SpatialPolygonsspTransform in packagergdal

Examples

library(lattice)grd <- GridTopology(cellcentre.offset=c(-175,55), cellsize=c(10,10), cells.dim=c(4,4))SpP_grd <- as.SpatialPolygons.GridTopology(grd)plot(SpP_grd)text(coordinates(SpP_grd), sapply(slot(SpP_grd, "polygons"), function(i) slot(i, "ID")), cex=0.5)trdata <- data.frame(A=rep(c(1,2,3,4), 4), B=rep(c(1,2,3,4), each=4), row.names=sapply(slot(SpP_grd, "polygons"), function(i) slot(i, "ID")))SpPDF <- SpatialPolygonsDataFrame(SpP_grd, trdata)spplot(SpPDF)data(meuse.grid)gridded(meuse.grid)=~x+yxx = spsample(meuse.grid,  type="hexagonal", cellsize=200)xxpl = HexPoints2SpatialPolygons(xx)image(meuse.grid["dist"])plot(xxpl, add = TRUE)points(xx, cex = .5)## Not run: spplot(aggregate(as(meuse.grid[,1:3], "SpatialPolygonsDataFrame"), xxpl, areaWeighted=TRUE), main = "aggregated meuse.grid")## End(Not run)

Making SpatialPolygons objects

Description

This function is used in making SpatialPolygons objects from other formats.

Usage

as.SpatialPolygons.PolygonsList(Srl, proj4string=CRS(as.character(NA)))

Arguments

Value

The functions return a SpatialPolygons object

Author(s)

Roger Bivand

Examples

grd <- GridTopology(c(1,1), c(1,1), c(10,10))polys <- as.SpatialPolygons.GridTopology(grd)plot(polys)text(coordinates(polys), labels=sapply(slot(polys, "polygons"), function(i) slot(i, "ID")), cex=0.6)

retrieve bbox from spatial data

Description

retrieves spatial bounding box from spatial data

Usage

bbox(obj)

Arguments

Value

two-column matrix; the first column has the minimum,the second the maximum values; rows represent the spatialdimensions

Methods

obj = "Spatial"

object deriving from class "Spatial"

obj = "ANY"

an array with at least two columns

obj = "Line"

object deriving from class "Line"

obj = "Lines"

object deriving from class "Lines"

obj = "Polygon"

object deriving from class "Polygon"

obj = "Polygons"

object deriving from class "Polygons"

Examples

# just 9 points on a grid:x <- c(1,1,1,2,2,2,3,3,3)y <- c(1,2,3,1,2,3,1,2,3)xy <- cbind(x,y)S <- SpatialPoints(xy)bbox(S)# data.framedata(meuse.grid)coordinates(meuse.grid) <- ~x+ygridded(meuse.grid) <- TRUEbbox(meuse.grid)

blue-pink-yellow color scheme, which also prints well on black/white printers

Description

Create a vector of ‘n’ “contiguous” colors.

Usage

 bpy.colors(n = 100, cutoff.tails = 0.1, alpha = 1.0)

Arguments

Value

A character vector, ‘cv’, of color names. This can be usedeither to create a user-defined color palette for subsequent graphicsby ‘palette(cv)’, a ‘col=’ specification in graphics functions or in‘par’.

Note

This color map prints well on black-and-white printers.

Author(s)

unknown; the pallette was posted to gnuplot-info a fewdecades ago; R implementation Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

rainbow,cm.colors

Examples

bpy.colors(10)p <- expand.grid(x=1:30,y=1:30)p$z <- p$x + p$ycoordinates(p) <- c("x", "y")gridded(p) <- TRUEimage(p, col = bpy.colors(100), asp = 1)# require(lattice)# trellis.par.set("regions", list(col=bpy.colors())) # make this default pallette

Create a bubble plot of spatial data

Description

Create a bubble plot of spatial data, with options for bicolourresidual plots (xyplot wrapper)

Usage

bubble(obj, zcol = 1, ..., fill = TRUE, maxsize = 3, do.sqrt = TRUE, pch, col = c("#d01c8b", "#4dac26"), key.entries = quantile(data[,zcol]), main, identify = FALSE, labels = row.names(data.frame(obj)), key.space = "right",scales = list(draw = FALSE), xlab = NULL, ylab = NULL, panel = panel.bubble,sp.layout = NULL, xlim = bbexpand(bbox(obj)[1,], 0.04), ylim = bbexpand(bbox(obj)[2,], 0.04))

Arguments

Value

returns (or plots) the bubble plot; ifidentify is TRUE, returnsthe indexes (row numbers) of identified points.

Author(s)

Edzer Pebesma

See Also

xyplot,mapasp,identify

Examples

data(meuse)coordinates(meuse) <- c("x", "y") # promote to SpatialPointsDataFramebubble(meuse, "cadmium", maxsize = 2.5, main = "cadmium concentrations (ppm)",     key.entries = 2^(-1:4))bubble(meuse, "zinc", main = "zinc concentrations (ppm)",    key.entries =  100 * 2^(0:4))

Convert character vector to DMS-class object

Description

These two helper functions convert character vectors and decimal degree vectors to the DMS-class representation of degrees, minutes, and decimal seconds. "DMS" objects cannot contain NAs.

Usage

char2dms(from, chd = "d", chm = "'", chs = "\"")dd2dms(dd, NS = FALSE)

Arguments

Details

In char2dms, the input data vector should use a regular format, such as that used in the PROJ.4 library, with a trailing capital (NSWE) indicating compass direction.

Value

Both functions return a "DMS" object.

Methods

from = "DMS", to = "numeric"

coerce a"DMS" object to a"numeric" vector

from = "DMS", to = "character"

coerce a"DMS" object to a"character" vector (theas.character.DMS S3 method is also available)

Author(s)

Roger BivandRoger.Bivand@nhh.no

See Also

DMS-class

Examples

data(state)str(state.center$y)stateN <- dd2dms(state.center$y, NS=TRUE)str(attributes(stateN))ch.stateN <- as.character(stateN)str(ch.stateN)stateNa <- char2dms(ch.stateN)str(attributes(stateNa))ch.stateN <- as(stateN, "character")str(ch.stateN)stateNa <- char2dms(ch.stateN)str(attributes(stateNa))

Display a compass rose.

Description

Displays a basic compass rose, usually to orient a map.

Usage

 compassRose(x,y,rot=0,cex=1)

Arguments

Details

‘⁠compassRose⁠’ displays a conventional compass rose at the positionrequested. The size of the compass rose is determined by the characterexpansion, as the central "rose" is calculated relative to the character size.Rotation is in degrees counterclockwise.

Value

nil

Author(s)

Jim Lemon

set spatial coordinates to create a Spatial object, or retrievespatial coordinates from a Spatial object

Description

set spatial coordinates to create a Spatial object, or retrievespatial coordinates from a Spatial object

Usage

coordinates(obj, ...)coordinates(object) <- value

Arguments

Value

usually an object of class SpatialPointsDataFrame; if the coordinatesset cover the full set of variables in object, an object of class SpatialPointsis returned

Examples

# data.framedata(meuse.grid)coordinates(meuse.grid) <- ~x+ygridded(meuse.grid) <- TRUEclass(meuse.grid)bbox(meuse.grid)data(meuse)meuse.xy = meuse[c("x", "y")]coordinates(meuse.xy) <- ~x+yclass(meuse.xy)

retrieve (or set) spatial coordinates

Description

retrieve (or set) spatial coordinates from (for) spatial data

Methods

obj = "list"

list with (at least) two numeric components of equal length

obj = "data.frame"

data.frame with at least two numeric components

obj = "matrix"

numeric matrix with at least two columns

obj = "SpatialPoints"

object of, or deriving from, SpatialPoints

obj = "SpatialPointsDataFrame"

object of, or deriving from, SpatialPointsDataFrame

obj = "SpatialPolygons"

object of, or deriving from, SpatialPolygons

obj = "SpatialPolygonsDataFrame"

object of, or deriving from, SpatialPolygonsDataFrame

obj = "Line"

object of class Line; returned value is matrix

obj = "Lines"

object of class Lines; returned value is list of matrices

obj = "SpatialLines"

object of, or deriving from, SpatialLines; returnedvalue is list of lists of matrices

obj = "GridTopology"

object of, or deriving from, GridTopology

obj = "GridTopology"

object of, or deriving from, GridTopology

obj = "SpatialPixels"

object of, or deriving from, SpatialPixels

obj = "SpatialPixelsDataFrame"

object of, or deriving from, SpatialPixelsDataFrame

obj = "SpatialGrid"

object of, or deriving from, SpatialGrid

obj = "SpatialGridDataFrame"

object of, or deriving from, SpatialGridDataFrame

Methods for "coordinates<-"

object = "data.frame", value="ANY"

promote data.frame to object of classSpatialPointsDataFrame-class, by specifying coordinates; seecoordinates

retrieve or assign coordinate names for classes in sp

Description

retrieve or assign coordinate names for classes insp

Methods for coordnames

x = "SpatialPoints"

retrieves coordinate names

x = "SpatialLines"

retrieves coordinate names

x = "Lines"

retrieves coordinate names

x = "Line"

retrieves coordinate names

x = "SpatialPolygons"

retrieves coordinate names

x = "Polygons"

retrieves coordinate names

x = "Polygon"

retrieves coordinate names

Methods for "coordnames<-"

x = "SpatialPoints", value = "character"

replace coordinate names

x = "SpatialLines", value = "character"

replace coordinate names

x = "Lines", value = "character"

replace coordinate names

x = "Line", value = "character"

replace coordinate names

x = "SpatialPolygons", value = "character"

replace coordinate names

x = "GridTopology", value = "character"

replace coordinate names

x = "SpatialGrid", value = "character"

replace coordinate names

x = "SpatialPixels", value = "character"

replace coordinate names

axis with degrees

Description

draw axes on a plot using degree symbols in numbers

Usage

degAxis(side, at, labels, ...)

Arguments

Value

axis is plotted on current graph

Note

decimal degrees are used if variation is small, instead of minutes and seconds

Examples

xy = cbind(x = 2 * runif(100) - 1, y = 2 * runif(100) - 1)plot(SpatialPoints(xy, proj4string = CRS("+proj=longlat +ellps=WGS84")),xlim=c(-1,1),ylim=c(-1,1))degAxis(1)degAxis(2, at = c(-1,-0.5,0,0.5,1))#

retrieve spatial dimensions from spatial data

Description

retrieves spatial dimensions box from spatial data

Usage

dimensions(obj)

Arguments

Value

two-column matrix; the first column has the minimum,the second the maximum values; rows represent the spatialdimensions

Methods

obj = "Spatial"

object deriving from class "Spatial"

Examples

# just 9 points on a grid:x <- c(1,1,1,2,2,2,3,3,3)y <- c(1,2,3,1,2,3,1,2,3)xy <- cbind(x,y)S <- SpatialPoints(xy)dimensions(S)# data.framedata(meuse.grid)coordinates(meuse.grid) <- ~x+ygridded(meuse.grid) <- TRUEdimensions(meuse.grid)

disaggregate SpatialLines, SpatialLinesDataFrame, SpatialPolygons, or SpatialPolygonsDataFrame objects

Description

disaggregate SpatialLines, SpatialLinesDataFrame, SpatialPolygons, or SpatialPolygonsDataFrame objects, using functions from rgeos to handle polygon hole nesting

Usage

 disaggregate(x, ...)

Arguments

Value

object of classSpatialLines orSpatialPolygons,where groups ofLine orPolygon are disaggregated tooneLine perLines, or onePolygonperPolygons, respectively.

Author(s)

Robert Hijmans, Edzer Pebesma

Methods for Function elide in Package ‘maptools’

Description

Methods for functionelide to translate and disguise coordinate placing in the real world.

Usage

elide(obj, ...)

Arguments

Value

The methods return objects of the input class object with elided coordinates; the coordinate reference system is not set. Note that if the input coordinates or centroids are in the data slot data.frame of the input object, they should be removed before the use of these methods, otherwise they will betray the input positions.

Methods

obj = "SpatialPoints"

elides object

obj = "SpatialPointsDataFrame"

elides object

obj = "SpatialLines"

elides object

obj = "SpatialLinesDataFrame"

elides object

obj = "SpatialPolygons"

elides object

obj = "SpatialPolygonsDataFrame"

elides object

Note

Rotation code kindly contributed by Don MacQueen

Examples

data(meuse)coordinates(meuse) <- c("x", "y")proj4string(meuse) <- CRS("+init=epsg:28992")data(meuse.riv)river_polygon <- Polygons(list(Polygon(meuse.riv)),)rivers <- SpatialPolygons(list(river_polygon))proj4string(rivers) <- CRS("+init=epsg:28992")rivers1 <- elide(rivers, reflect=c(TRUE, TRUE), scale=TRUE)meuse1 <- elide(meuse, bb=bbox(rivers), reflect=c(TRUE, TRUE), scale=TRUE)opar <- par(mfrow=c(1,2))plot(rivers, axes=TRUE)plot(meuse, add=TRUE)plot(rivers1, axes=TRUE)plot(meuse1, add=TRUE)par(opar)meuse1 <- elide(meuse, shift=c(10000, -10000))bbox(meuse)bbox(meuse1)rivers1 <- elide(rivers, shift=c(10000, -10000))bbox(rivers)bbox(rivers1)meuse1 <- elide(meuse, rotate=-30, center=apply(bbox(meuse), 1, mean))bbox(meuse)bbox(meuse1)plot(meuse1, axes=TRUE)

rearrange data in SpatialPointsDataFrame or SpatialGridDataFrame for plotting with spplot (levelplot/xyplot wrapper)

Description

rearrange SpatialPointsDataFrame for plotting with spplot or levelplot

Usage

flipHorizontal(x)flipVertical(x)

Arguments

Value

object of class SpatialGridDataFrame, with pixels flipped horizontallyor vertically. Note that the spatial structure is destroyed (or at least:drastically changed).

Author(s)

Michael Sumner

Examples

data(meuse.grid) # data framegridded(meuse.grid) = c("x", "y") # promotes to fullgrid(meuse.grid) = TRUEd = meuse.grid["dist"]image(d, axes=TRUE)image(flipHorizontal(d), axes=TRUE)image(flipVertical(d), axes=TRUE)

Methods for retrieving the geometry from a composite (geometry + attributes) object

Description

geometry retrieves the SpatialXxx object from a SpatialXxxDataFrame object,with Xxx Lines, Points, Polygons, Grid, or Pixels. geometry<- converts adata.frame into a Spatial object.

Usage

 geometry(obj) geometry(obj) <- value

Arguments

Methods

obj = "Spatial"

obj = "SpatialPointsDataFrame"

obj = "SpatialMultiPointsDataFrame"

obj = "SpatialPolygonsDataFrame"

obj = "SpatialPixelsDataFrame"

obj = "SpatialGridDataFrame"

obj = "SpatialLinesDataFrame"

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

Examples

data(meuse)m = meusecoordinates(m) = meuse[, c("x", "y")]pts = geometry(m)class(pts)geometry(meuse) = ptsclass(meuse)identical(m, meuse) # TRUE

create neighbourhood (nb) object from grid geometry

Description

create neighbourhood (nb) object from grid geometry

Usage

 gridIndex2nb(obj, maxdist = sqrt(2), fullMat = TRUE, ...)

Arguments

Value

Object of class nb, which is a list.

The nb object follows the convention of nb objects in package spdep;it is a list with each list element corresponding to a grid cell orpixel; the list element contains the indices of neighbours definedas cells less than maxdist away, measured in cell unit (N/S/E/Wneighbour has distance 1).

Note

Unequal grid cell size is ignored; grid cell row/col indicesare taken to be the coordinates from which distances are computed.

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

plot.nb in package spdep

specify spatial data as being gridded, or find out whether they are

Description

returns logical (TRUE or FALSE) telling whether the object is griddedor not; in assignment promotes a non-gridded structure to a griddedone, or demotes a gridded structure back to a non-structured one.

Usage

gridded(obj)gridded(obj) <- valuefullgrid(obj)fullgrid(obj) <- valuegridparameters(obj)

Arguments

Value

if obj derives from class Spatial, gridded(object) will tellwhether it is has topology on a regular grid; if assigned TRUE, if theobject derives from SpatialPoints and has gridded topology,grid topology will be added to object, and the class of the objectwill be promoted toSpatialGrid-class orSpatialGridDataFrame-class

fullgrid returns a logical, telling whether the grid is fulland ordered (i.e., in full matrix form), or whether it is not fullor unordered (i.e. a list of points that happen to lie on a grid. Ifassigned, the way the points are stored may be changed. Changing a setof points to full matrix form and back may change the original order ofthe points, and will remove duplicate points if they were present.

gridparameters returns, ifobj inherits fromSpatialGridDataFrame its grid parameters, else it returns numeric(0). Thereturned value is a data.frame with three columns, named cellcentre.offset("lower left cell centre coordinates"), cellsize, and cells.dim (celldimension); the rows correspond to the spatial dimensions.

Methods

obj = "Spatial"

object deriving from class "Spatial"

Examples

# just 9 points on a grid:x <- c(1,1,1,2,2,2,3,3,3)y <- c(1,2,3,1,2,3,1,2,3)xy <- cbind(x,y)S <- SpatialPoints(xy)class(S)plot(S)gridded(S) <- TRUEgridded(S)class(S)summary(S)plot(S)gridded(S) <- FALSEgridded(S)class(S)# data.framedata(meuse.grid)coordinates(meuse.grid) <- ~x+ygridded(meuse.grid) <- TRUEplot(meuse.grid) # not much goodsummary(meuse.grid)

Create N-S and E-W grid lines over a geographic region

Description

Create N-S and E-W grid lines over a geographic region; create and plot corresponding labels

Usage

gridlines(x, easts = pretty(bbox(x)[1,]), norths = pretty(bbox(x)[2,]), ndiscr = 100) gridat(x, easts = pretty(bbox(x)[1,]), norths = pretty(bbox(x)[2,]), offset = 0.5, side = "WS")## S3 method for class 'SpatialLines'labels(object, labelCRS, side = 1:2, ...)## S3 method for class 'SpatialPointsDataFrame'text(x, ...)

Arguments

Value

gridlines returns an object of classSpatialLines-class, with lines as specified; the returnobject inherits the projection information ofx;gridatreturns a SpatialPointsDataFrame with points at the west and southends of the grid lines created bygridlines, with degreelabels.

Thelabels method forSpatialLines objects returns aSpatialPointsDataFrame-class object with the parameters neededto print labels below and left of the gridlines. The locations forthe labels are those ofproj4string(object) the labels alsounlesslabelCRS is given, in which case they are in that CRS.This object is prepared to be plotted withtext:

Thetext method forSpatialPointsDataFrame puts text labelson its coordinates, and takes care of attributespos,labels,srt andoffset; seetext.

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de, using example codeof Roger Bivand.

See Also

spTransform

Examples

run <- FALSEif (requireNamespace("sf", quietly=TRUE)) run <- TRUEdata(meuse)coordinates(meuse) = ~x+yplot(meuse)plot(gridlines(meuse), add = TRUE)text(labels(gridlines(meuse)))title("default gridlines within Meuse bounding box")if (run) {proj4string(meuse) <- CRS("+init=epsg:28992")crs.longlat <- CRS("+init=epsg:4326")meuse_ll <- spTransform(meuse, crs.longlat)grd <- gridlines(meuse_ll)grd_x <- spTransform(grd, CRS("+init=epsg:28992"))# labels South and West:plot(meuse)plot(grd_x, add=TRUE, lty=2)grdat_ll <- gridat(meuse_ll)grdat_x <- spTransform(grdat_ll, CRS("+init=epsg:28992"))text(grdat_x)}if (run) {# labels North and East:plot(meuse)plot(grd_x, add=TRUE, lty=2)grdat_ll <- gridat(meuse_ll, side="EN")grdat_x <- spTransform(grdat_ll, CRS("+init=epsg:28992"))text(grdat_x)}if (run) {# now using labels:plot(meuse)plot(grd_x, add=TRUE, lty=2)text(labels(grd_x, crs.longlat))}if (run) {# demonstrate axis labels with angle, both sides:sp = SpatialPoints(rbind(c(-101,9), c(-101,55), c(-19,9), c(-19,55)), crs.longlat)laea = CRS("+proj=laea +lat_0=30 +lon_0=-40")sp.l = spTransform(sp, laea)plot(sp.l, expandBB = c(0, 0.05, 0, .05))gl = spTransform(gridlines(sp), laea)plot(gl, add = TRUE)text(labels(gl, crs.longlat))text(labels(gl, crs.longlat, side = 3:4), col = 'red')title("curved text label demo")}if (run) {# polar:pts=SpatialPoints(rbind(c(-180,-70),c(0,-70),c(180,-89),c(180,-70)), crs.longlat)polar = CRS("+init=epsg:3031")gl = spTransform(gridlines(pts, easts = seq(-180,180,20), ndiscr = 100), polar)plot(spTransform(pts, polar), expandBB = c(.05,0,.05,0))lines(gl)l = labels(gl, crs.longlat, side = 3)l$pos = NULL # pos is too simple, use adj:text(l, adj = c(0.5, -0.5)) l = labels(gl, crs.longlat, side = 4)l$srt = 0 # otherwise they end up upside-downtext(l)title("grid line labels on polar projection, epsg 3031")}## Not run: if (require(maps)) demo(polar) # adds the map of the antarctic## End(Not run)

Image or contour method for gridded spatial data; convert to and from image data structure

Description

Create image for gridded data in SpatialGridDataFrame or SpatialPixelsDataFrameobjects.

Usage

## S3 method for class 'SpatialGridDataFrame'image(x, attr = 1, xcol = 1, ycol = 2, col = heat.colors(12), red=NULL, green=NULL, blue=NULL,        axes = FALSE, xlim = NULL,ylim = NULL, add = FALSE, ..., asp = NA, setParUsrBB=FALSE,        interpolate = FALSE, angle = 0, useRasterImage = !(.Platform$GUI[1] == "Rgui" &&        getIdentification() == "R Console") && missing(breaks), breaks,zlim = range(as.numeric(x[[attr]])[is.finite(x[[attr]])]))## S3 method for class 'SpatialPixelsDataFrame'image(x, ...) ## S3 method for class 'SpatialPixels'image(x, ...) ## S3 method for class 'SpatialGridDataFrame'contour(x, attr = 1, xcol = 1, ycol = 2,col = 1, add = FALSE, xlim = NULL, ylim = NULL, axes = FALSE,         ..., setParUsrBB = FALSE)## S3 method for class 'SpatialPixelsDataFrame'contour(x, ...) as.image.SpatialGridDataFrame(x, xcol = 1, ycol = 2, attr = 1)image2Grid(im, p4 = as.character(NA), digits=10)

Arguments

Value

as.image.SpatialGridDataFrame returns the list withelementsx andy, containing the coordinates of the cellcentres of a matrixz, containing the attribute values in matrixform as needed byimage.

Note

Providingxcol andycol attributes seems obsolete,and it is for 2D data, but it may provide opportunities for plottingcertain slices in 3D data. I haven't given this much thought yet.

filled.contour seems to misinterpret the coordinate values,if we take the image.default manual page as the reference.

Author(s)

Edzer Pebesma

See Also

image.default,SpatialGridDataFrame-class,levelplot in packagelattice. Functionimage.plot in packagefields can be used to make a legend for an image, see an example inhttps://stat.ethz.ch/pipermail/r-sig-geo/2007-June/002143.html

Examples

data(meuse.grid)coordinates(meuse.grid) = c("x", "y") # promote to SpatialPointsDataFramegridded(meuse.grid) = TRUE            # promote to SpatialGridDataFramedata(meuse)coordinates(meuse) = c("x", "y")image(meuse.grid["dist"], main = "Distance to river Meuse")points(coordinates(meuse), pch = "+")image(meuse.grid["dist"], main = "Distance to river Meuse", useRasterImage=TRUE)points(coordinates(meuse), pch = "+")# color scale:layout(cbind(1,2), c(4,1),1)image(meuse.grid["dist"])imageScale(meuse.grid$dist, axis.pos=4, add.axis=FALSE)axis(4,at=c(0,.2,.4,.8), las=2)data(Rlogo)d = dim(Rlogo)cellsize = abs(c(gt[2],gt[6]))cells.dim = c(d[1], d[2]) # c(d[2],d[1])cellcentre.offset = c(x = gt[1] + 0.5 * cellsize[1], y = gt[4] - (d[2] - 0.5) * abs(cellsize[2]))grid = GridTopology(cellcentre.offset, cellsize, cells.dim)df = as.vector(Rlogo[,,1])for (band in 2:d[3]) df = cbind(df, as.vector(Rlogo[,,band]))df = as.data.frame(df)names(df) = paste("band", 1:d[3], sep="")Rlogo <- SpatialGridDataFrame(grid = grid, data = df)summary(Rlogo)image(Rlogo, red="band1", green="band2", blue="band3")image(Rlogo, red="band1", green="band2", blue="band3", useRasterImage=FALSE)is.na(Rlogo$band1) <- Rlogo$band1 == 255is.na(Rlogo$band2) <- Rlogo$band2 == 255is.na(Rlogo$band3) <- Rlogo$band3 == 255Rlogo$i7 <- 7image(Rlogo, "i7")image(Rlogo, red="band1", green="band2", blue="band3", add=TRUE)

Sets or retrieves projection attributes on classes extendingSpatialData

Description

Sets or retrieves projection attributes on classes extendingSpatialData; set or retrieve option value for error or warning on exceedance of geographical coordinate range, set or retrieve option value for exceedance tolerance of geographical coordinate range. Note that only “+proj=longlat +ellps=WGS84” is accepted for geographical coordinates, which must be ordered (eastings, northings); the “+ellps=” definition must be given (or expanded internally from a given “+datum=” value) for recent versions of the PROJ library, and should be set to an appropriate value.

From release 6 of the PROJ library, when used in buildingrgdal with GDAL >= 3, the+datum= key in the Proj.4 string CRS representation is deprecated, and the+towgs84= and+nadgrids= keys may be deprecated soon. For this reason,sp,rgdal andsf are starting to use WKT2 (2019) string representations. Insp, the"CRS" object in itself remains unchanged, but the content of its"projargs" slot may be degraded. To work around the degradation, acomment is added around the"CRS" object containing a WKT2 (2019) string whenrgdal is available and built with PROJ >= 6 and GDAL >=3. Thewkt() accessor function returns the WKT2 (2019) string comment belonging to the"CRS" object.

Usage

is.projected(obj)proj4string(obj)proj4string(obj) <- valuewkt(obj)get_ll_warn()get_ll_TOL()get_ReplCRS_warn()set_ll_warn(value)set_ll_TOL(value)set_ReplCRS_warn(value)

Arguments

Details

proj4 strings are operative through CRAN package rgdal. For strings defined as “longlat”, the minimum longitude should be -180, the maximum longitude 360, the minimum latitude -90, and the maximum latitude 90. Note that theproj4string replacement method does not project spatial data - for this usespTransform methods in the rgdal package.

Value

is.projected returns a logical that may beNA;proj4string returns a character vector of length 1.

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

CRS

Examples

o <- new("Spatial")proj4string(o) <- CRS("+init=epsg:27700")if (!is.null(comment(slot(o, "proj4string")))) {  cat(strsplit(wkt(o), "\n")[[1]], sep="\n")  cat(strsplit(wkt(slot(o, "proj4string")), "\n")[[1]], sep="\n")}is.projected(CRS("+proj=longlat"))is.projected(CRS("+proj=geocent"))is.projected(CRS("+proj=geocent +units=km"))

deprecated function to load the Meuse data set

Description

deprecated function to load the Meuse data set

Usage

loadMeuse()

Value

none; it prints a warning to run demo(meuse)

See Also

meuse,meuse.grid

Examples

demo(meuse)

Calculate aspect ratio for plotting geographic maps;create nice degree axis labels

Description

Calculate aspect ratio for plotting geographic maps;create nice degree axis labels

Usage

 mapasp(data, xlim, ylim)degreeLabelsEW(x)degreeLabelsNS(x)

Arguments

Value

mapasp is used for the aspect argument in lattice plots and spplot;

let x = dy/dx, with dy and dx the y- and x-size of the map.

let s = 1/cos((My * pi)/180) with My the y coordinate of the middle of the map(the mean of ylim)

for latlong (longlat) data,mapasp returns s * x.for other data, mapasp returns "iso".

Note

the values forx are typically obtained fromaxTicks

See Also

levelplot in packagelattice

Merge a Spatial* object having attributes with a data.frame

Description

Merge a Spatial object having a data.frame (i.e. merging of non-spatial attributes).

Usage

## S4 method for signature 'Spatial,data.frame'merge(x, y, by = intersect(names(x), names(y)), by.x = by, by.y = by, all.x = TRUE, suffixes = c(".x",".y"), incomparables = NULL, duplicateGeoms = FALSE, ...)

Arguments

Value

a Spatial* object

Author(s)

Robert J. Hijmans

See Also

merge

Meuse river data set

Description

This data set gives locations and topsoil heavy metal concentrations, along with a number of soil and landscape variables at the observation locations, collected in a flood plain of the river Meuse, near the village of Stein (NL). Heavy metal concentrations are from composite samples of an area of approximately 15 m x 15 m.

Usage

data(meuse)

Format

This data frame contains the following columns:

x

a numeric vector; Easting (m) in Rijksdriehoek (RDH)(Netherlands topographical) map coordinates

y

a numeric vector; Northing (m) in RDH coordinates

cadmium

topsoil cadmium concentration, mg kg-1 soil ("ppm"); zero cadmiumvalues in the original data set have been shifted to 0.2 (half the lowest non-zero value)

copper

topsoil copper concentration, mg kg-1 soil ("ppm")

lead

topsoil lead concentration, mg kg-1 soil ("ppm")

zinc

topsoil zinc concentration, mg kg-1 soil ("ppm")

elev

relative elevation above local river bed, m

dist

distance to the Meuse; obtained from the nearest cell inmeuse.grid, which in turn was derived by a spread (spatial distance)GIS operation, horizontal precision 20 metres; thennormalized to $[0,1]$

om

organic matter, kg (100 kg)-1 soil (percent)

ffreq

flooding frequency class: 1 = once in two years; 2 = once in ten years; 3 = one in 50 years

soil

soil type according to the 1:50 000 soil map of the Netherlands. 1 = Rd10A (Calcareous weakly-developed meadow soils, light sandy clay); 2 = Rd90C/VII (Non-calcareous weakly-developed meadow soils, heavy sandy clay to light clay); 3 = Bkd26/VII (Red Brick soil, fine-sandy, silty light clay)

lime

lime class: 0 = absent, 1 = present by field test with 5% HCl

landuse

landuse class: Aa Agriculture/unspecified = , Ab = Agr/sugar beetsm, Ag = Agr/small grains, Ah = Agr/??, Am = Agr/maize, B = woods, Bw = trees in pasture, DEN = ??, Fh = tall fruit trees, Fl = low fruit trees; Fw = fruit trees in pasture, Ga = home gardens, SPO = sport field, STA = stable yard, Tv = ??, W = pasture

dist.m

distance to river Meuse in metres, as obtained during the field survey

Note

row.names refer to the original sample number.

Soil units were mapped with a minimum delination width of 150 m, and so somewhat generalize the landscape.

Approximate equivalent World Reference Base 2002 for Soil Resources names are: Rd10A Gleyic Fluvisols; Rd90C Haplic Fluvisols; Bkd26 Haplic Luvisols. Units Rd90C and Bkd26 have winter groundwater > 80cm, summer > 120cm depth.

Author(s)

Field data were collected by Ruud van Rijn andMathieu Rikken; compiled for R by Edzer Pebesma; description extended by David Rossiter

References

M G J Rikken and R P G Van Rijn, 1993. Soil pollution with heavy metals - an inquiry into spatial variation, cost of mapping and the risk evaluation of copper, cadmium, lead and zinc in the floodplains of the Meuse west of Stein, the Netherlands. Doctoraalveldwerkverslag, Dept. of Physical Geography, Utrecht University

P.A. Burrough, R.A. McDonnell, 1998. Principles of Geographical Information Systems. Oxford University Press.

Stichting voor Bodemkartering (STIBOKA), 1970. Bodemkaart van Nederland : Blad 59 Peer, Blad 60 West en 60 Oost Sittard: schaal 1 : 50 000. Wageningen, STIBOKA.

http://www.gstat.org/

Examples

data(meuse)summary(meuse)coordinates(meuse) <- ~x+yproj4string(meuse) <- CRS("+init=epsg:28992")

Prediction Grid for Meuse Data Set

Description

Themeuse.grid data frame has 3103 rows and 7 columns;a grid with 40 m x 40 m spacing that covers the Meuse study area (seemeuse)

Usage

data(meuse.grid)

Format

This data frame contains the following columns:

x

a numeric vector; x-coordinate (seemeuse)

y

a numeric vector; y-coordinate (seemeuse)

dist

distance to the Meuse river; obtained by a spread(spatial distance) GIS operation, from border of river; normalized to$[0,1]$

ffreq

flooding frequency class, for definitions see this item inmeuse; it is not known how this map was generated

part.a

arbitrary division of the area in two areas, a and b

part.b

seepart.a

soil

soil type, for definitions see this item inmeuse; it is questionable whether these data come from a real soil map, they do not match the published 1:50 000 map

Details

x andy are in RD New, the Dutch topographical mapcoordinate system. Roger Bivand projected this to UTM in theR-Grass interface package.

Source

http://www.gstat.org/

References

See themeuse documentation

Examples

data(meuse.grid)coordinates(meuse.grid) = ~x+yproj4string(meuse.grid) <- CRS("+init=epsg:28992")gridded(meuse.grid) = TRUEspplot(meuse.grid)

Prediction Grid for Meuse Data Set, geographical coordinates

Description

The object contains the meuse.grid data as a SpatialPointsDataFrame after transformation to WGS84 and geographical coordinates.

Usage

data(meuse.grid_ll)

Format

The format is:Formal class 'SpatialPointsDataFrame' [package "sp"].

Source

See themeuse documentation

Examples

data(meuse.grid_ll)

River Meuse outline

Description

Themeuse.riv data consists of an outline of the Meuseriver in the area a few kilometers around themeusedata set.

Themeuse.area polygon has an outline ofmeuse.grid. Seeexample below how it can be created frommeuse.grid.

Usage

data(meuse.riv)data(meuse.area)

Format

meuse.riv: two-column data.frame containing 176 coordinates.

meuse.area: two-column matrix with coordinates of outline.

Details

x andy are in RDM, the Dutch topographical mapcoordinate system. See examples ofspTransform for projection parameters.

References

See themeuse documentation

Examples

data(meuse.riv)plot(meuse.riv, type = "l", asp = 1)data(meuse.grid)coordinates(meuse.grid) = c("x", "y")gridded(meuse.grid) = TRUEimage(meuse.grid, "dist", add = TRUE)data(meuse)coordinates(meuse) = c("x", "y")meuse.sr = SpatialPolygons(list(Polygons(list(Polygon(meuse.riv)),"meuse.riv")))spplot(meuse.grid, col.regions=bpy.colors(), main = "meuse.grid",  sp.layout=list(list("sp.polygons", meuse.sr),list("sp.points", meuse, pch="+", col="black")  ))spplot(meuse, "zinc", col.regions=bpy.colors(),  main = "zinc, ppm",  cuts = c(100,200,400,700,1200,2000), key.space = "right",  sp.layout= list("sp.polygons", meuse.sr, fill = "lightblue"))

consistent spatial overlay for points, grids and polygons

Description

consistent spatial overlay for points, grids andpolygons: at the spatial locations of object x retrieves the indexesor attributes from spatial object y

Usage

over(x, y, returnList = FALSE, fn = NULL, ...)x %over% y

Arguments

Value

Ify is only geometry an object of lengthlength(x).IfreturnList isFALSE, a vector with the (first) indexofy for each geometry (point, grid cell centre, polygonor lines) matchingx. ifreturnList is TRUE, a list oflengthlength(x), with list elementi the vector ofall indices of the geometries iny that correspond to the$i$-th geometry inx.

Ify has attribute data, attribute data arereturned.returnList is FALSE, adata.frame withnumber of rows equal tolength(x) is returned, if it isTRUE a list withlength(x) elements is returned, with a listelement thedata.frame elements of all geometries inythat correspond to that element ofx.

Methods

x = "SpatialPoints", y = "SpatialPolygons"

returns a numericvector of length equal to the number of points; the number is theindex (number) of the polygon ofy in which a point falls;NA denotes the point does not fall in a polygon; if a point fallsin multiple polygons, the last polygon is recorded.

x = "SpatialPointsDataFrame", y = "SpatialPolygons"

equalto the previous method, except that an argumentfn=xxx isallowed, e.g.fn = mean which will then report a data.framewith the mean attribute values of thex points falling in each polygon (set) ofy

x = "SpatialPoints", y = "SpatialPolygonsDataFrame"

returnsa data.frame of the second argument with row entries correspondingto the first argument

x = "SpatialPolygons", y = "SpatialPoints"

returnsthe polygon index of points iny; ifx isaSpatialPolygonsDataFrame, a data.frame with rows fromx corresponding to points iny is returned.

x = "SpatialGridDataFrame", y = "SpatialPoints"

returnsobject of class SpatialPointsDataFrame with grid attribute valuesx at spatial point locations y; NA for NA grid cells or pointsoutside grid, and NA values on NA grid cells.

x = "SpatialGrid", y = "SpatialPoints"

returns grid valuesx at spatial point locations y; NA for NA grid cells or pointsoutside the grid

x = "SpatialPixelsDataFrame", y = "SpatialPoints"

returnsgrid values x at spatial point locations y; NA for NA grid cellsor points outside the grid

x = "SpatialPixels", y = "SpatialPoints"

returns gridvalues x at spatial point locations y; NA for NA grid cells orpoints outside the grid

x = "SpatialPoints", y = "SpatialGrid"

xx

x = "SpatialPoints", y = "SpatialGridDataFrame"

xx

x = "SpatialPoints", y = "SpatialPixels"

xx

x = "SpatialPoints", y = "SpatialPixelsDataFrame"

xx

x = "SpatialPolygons", y = "SpatialGridDataFrame"

xx

Note

over can be seen as a left outer join in SQL; thematch is a spatial intersection.

points on a polygon boundary and points corresponding to apolygon vertex are considered to be inside the polygon.

These methods assume that pixels and grid cells are neveroverlapping; for objects of classSpatialPixels this isnot guaranteed.

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

See Also

vignette("over") for examples and figures

panel and panel utility functions for spplot

Description

panel functions for spplot functions, and functions that can beuseful within these panel functions

Usage

spplot.key(sp.layout, rows = 1, cols = 1)SpatialPolygonsRescale(obj, offset, scale = 1, fill = "black", col = "black",plot.grid = TRUE, ...)sp.lines(obj, col = 1, ...)sp.points(obj, pch = 3, ...)sp.polygons(obj, col = 1, fill = "transparent", ...)sp.grid(obj, col = 1, alpha = 1,..., at = pretty(obj[[1]]), col.regions = col)sp.text(loc, txt, ...)sp.panel.layout(lst, p.number, ...)bbexpand(x, fraction)

Arguments

Note

The panel functions ofspplot,panel.gridplot for grids,panel.pointsplot for points, orpanel.polygonsplot for linesor polygons can be called with arguments(x,y,...).Customizing spplot plots can be done by extending the panel function,or by supplying an sp.layout argument; see the documentation forspplot. Inside these panel functions,sp.panel.layoutis called to deal with plotting the items in asp.layout object.

SpatialPolygonsRescale scales and shifts an object of classSpatialPolygons-class; this is useful e.g. for scale bars, or otherlayout items.

sp.lines,sp.points,sp.polygons andsp.textplot lines, points, polygons or text in a panel.

spplot.key draws thesp.layout object at given rows/cols.

sp.pagefn can be passed as apage argument, and willcall functionspplot.key for the last panel drawn on a page.

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

References

https://edzer.github.io/sp/ has a graph gallery withexamples with R code.

See Also

spplot,spplot-methods

do point(s) fall in a given polygon?

Description

verifies for one or more points whether they fall in a given polygon

Usage

point.in.polygon(point.x, point.y, pol.x, pol.y, mode.checked=FALSE)

Arguments

Value

integer array; values are:0: point is strictly exterior to pol;1: point is strictly interior to pol;2: point lies on the relative interior of an edge of pol;3: point is a vertex of pol.

References

Uses the C function InPoly(). InPoly is Copyright (c) 1998 byJoseph O'Rourke. It may be freely redistributed in its entiretyprovided that this copyright notice is not removed.

Examples

# open polygon:point.in.polygon(1:10,1:10,c(3,5,5,3),c(3,3,5,5))# closed polygon:point.in.polygon(1:10,rep(4,10),c(3,5,5,3,3),c(3,3,5,5,3))

sets spatial coordinates to create spatial data, or retrievesspatial coordinates

Description

sets spatial coordinates to create spatial data, or retrievesspatial coordinates

Usage

polygons(obj)polygons(object) <- value

Arguments

Value

polygons returns the SpatialPolygons of obj; polygons<- promotes adata.frame to a SpatialPolygonsDataFrame object

Examples

grd <- GridTopology(c(1,1), c(1,1), c(10,10))polys <- as.SpatialPolygons.GridTopology(grd)centroids <- coordinates(polys)x <- centroids[,1]y <- centroids[,2]z <- 1.4 + 0.1*x + 0.2*y + 0.002*x*xdf <- data.frame(x=x, y=y, z=z, row.names=row.names(polys))polygons(df) <- polysclass(df)summary(df)

Retrieve polygons from SpatialPolygonsDataFrame object

Description

Retrieve polygons from SpatialPolygonsDataFrame object

Methods for polygons

obj = "SpatialPolygons"

object of, or deriving from, SpatialPolygons

obj = "SpatialPolygonsDataFrame"

object of, or deriving from, SpatialPolygonsDataFrame

Methods for "polygons<-"

object = "data.frame", value="SpatialPolygons"

promote data.frame to object of classSpatialPolygonsDataFrame-class, by specifying polygons

read/write to/from (ESRI) asciigrid format

Description

read/write to/from ESRI asciigrid format

Usage

 read.asciigrid(fname, as.image = FALSE, plot.image = FALSE, colname = fname, proj4string = CRS(as.character(NA)))write.asciigrid(x, fname, attr = 1, na.value = -9999, ...)

Arguments

Value

read.asciigrid returns the grid map read; either asan object of classSpatialGridDataFrame-class or, ifas.image is TRUE, as list with componentsx,y andz.

Author(s)

Edzer Pebesma

See Also

as.image.SpatialGridDataFrame,image

Examples

x <- read.asciigrid(system.file("external/test.ag", package="sp")[1])class(x)image(x)

Methods for Function recenter in Package ‘sp’

Description

Methods for functionrecenter in packagesp to shift or re-center geographical coordinates for a Pacific view. All longitudes < 0 are added to 360, to avoid for instance parts of Alaska being represented on the far left and right of a plot because they have values straddling 180 degrees. In general, using a projected coordinate reference system is to be preferred, but this method permits a geographical coordinate reference system to be used. This idea was suggested by Greg Snow, and corresponds to the two world representations in themaps package.

Methods

obj = "SpatialPolygons"

recenter a SpatialPolygons object

obj = "Polygons"

recenter a Polygons object

obj = "Polygon"

recenter an Polygon object

obj = "SpatialLines"

recenter a SpatialLines object

obj = "Lines"

recenter a Lines object

obj = "Line"

recenter an Line object

Examples

crds <- matrix(c(179, -179, -179, 179, 50, 50, 52, 52), ncol=2)SL <- SpatialLines(list(Lines(list(Line(crds)), "1")), CRS("+proj=longlat +ellps=WGS84"))bbox(SL)SLr <- recenter(SL)bbox(SLr)rcrds <- rbind(crds, crds[1,])SpP <- SpatialPolygons(list(Polygons(list(Polygon(rcrds)),)), proj4string=CRS("+proj=longlat +ellps=WGS84"))bbox(SpP)SpPr <- recenter(SpP)bbox(SpPr)opar <- par(mfrow=c(1,2))plot(SpP)plot(SpPr)par(opar)crds <- matrix(c(-1, 1, 1, -1, 50, 50, 52, 52), ncol=2)SL <- SpatialLines(list(Lines(list(Line(crds)), "1")), CRS("+proj=longlat +ellps=WGS84"))bbox(SL)SLr <- recenter(SL)bbox(SLr)rcrds <- rbind(crds, crds[1,])SpP <- SpatialPolygons(list(Polygons(list(Polygon(rcrds)),)), proj4string=CRS("+proj=longlat +ellps=WGS84"))bbox(SpP)SpPr <- recenter(SpP)bbox(SpPr)opar <- par(mfrow=c(1,2))plot(SpP)plot(SpPr)par(opar)

select points spatially

Description

select a number of points by digitizing the area they fall in

Usage

select.spatial(data, digitize = TRUE, pch = "+", rownames = FALSE)

Arguments

Value

if rownames == FALSE, array with either indexes (row numbers)of points inside the digitized polygon; if rownames == TRUE, characterarray with corresponding row names in the data.frame part

See Also

point.in.polygon,locator,SpatialPoints-class,SpatialPointsDataFrame-class

Examples

data(meuse)## the following command requires user interaction: left mouse## selects points, right mouse ends digitizingdata(meuse)coordinates(meuse) = c("x", "y")# select.spatial(meuse)

A package providing classes and methods for spatial data: points,lines, polygons and grids

Description

This package provides S4 classes for importing, manipulating and exportingspatial data in R, and for methods including print/show, plot, subset,[,[[,\$, names, dim, summary, and a number ofmethods specific to spatial data handling.

Introduction

Several spatial statistical packages have been around for a long while,but no organized set of classes for spatial data has yet been devised.Many of the spatial packages make their own assumptions, or use theirown class definitions for spatial data, making it inconvenient to movefrom one package to another. This package tries to provide a solid setof classes for many different types of spatial data. The idea is thatspatial statistical packages will either support these classes (i.e.,directly read and write them) or will provide conversion to them, so thatwe have a base class set with which any package can exchange. This way,many-to-many conversions can be replace with one-to-many conversions,provided either in this package or the spatial packages. Wherever possibleconversion (coercion) functions are automatic, or provided by sp.

External packages that depend on sp will provide importing and exportingfrom and to external GIS formats, e.g. through GDAL, OGR or shapelib.

In addition, this package tries to provide convenient methods to print,summarize and plot such spatial data.

Dimensions

In principal, geographical data are two-dimensional, on a flat surface (amap) or on a sphere (the earth). This package provides space for dealingwith higher dimensional data where possible; this is e.g. very simplefor points and grids, but hard to do for polygons. Plotting functionsare devised primarily for two-dimensional data, or two-dimensionalprojections of higher dimensional data.

Coordinate reference systems

Central to spatial data is that they have a coordinate reference system,which is coded in object of CRS class. Central to operations on differentspatial data sets is that their coordinate reference system is compatible(i.e., identical).

This CRS can be a character string describing a reference system ina way understood by the PROJ.4 projection library, or a (character)missing value. An interface to the PROJ.4 library is available only ifthe R package rgdal is present.

Class structure

All spatial classes derive from a basic classSpatial, which onlyprovides a bounding box and a CRS. This class has no useful instances, butuseful derived classes.

SpatialPoints extends Spatial and has coordinates. The methodcoordinates extracts the numeric matrix with coordinates from anobject of class SpatialPoints, or from other (possibly derived) classesthat have points.

Objects of class SpatialGrid points on a regular grid. Either a full gridis stored or a partial grid (i.e., only the non-missing valued cells);callingcoordinates on them will give the coordinates for thegrid cells.

SpatialPoints, SpatialPixels and SpatialGrid can be of arbitrarydimension, although most of the effort is in making them work for twodimensional data.

SpatialLines provides lines, and SpatialPolygons provides polygons, i.e.,lines that end where they start and do not intersect with itself.SpatialLines and SpatialPolygons only have two-dimensional data.

SpatialPointsDataFrame extends SpatialPoints with a data slot, havinga data.frame with attribute data. Similarly, SpatialPixelsDataFrame,SpatialLinesDataFrame, SpatialPolygonsDataFrame extend the primaryspatial information with attribute data.

References

PROJ.4:https://github.com/OSGeo/PROJ

GDAL and OGR:https://gdal.org/.

Authors

sp is a collaborative effort of Edzer Pebesma, Roger Bivand, BarryRowlingson and Virgilo G\'omez-Rubio.

Deprecated functions in sp

Description

Deprecated functions is sp: getSpP*, getPolygon*, getLines* getSL*

Usage

set_evolution_status(value)get_evolution_status()

Arguments

Note

Foroverlay the new implementation is found in theover method; this works slightly different and more consistent.

write map data for Mondrian

Description

The function outputs a SpatialPolygonsDataFrame object to be used by Mondrian

Usage

sp2Mondrian(SP, file, new_format=TRUE)

Arguments

Note

At this release, the function writes out a text file with both data and polygon(s) identified as belonging to each row of data.

Author(s)

Patrick Hausmann and Roger Bivand

References

https://www.theusrus.de/Mondrian/, Ihaka Lecture 1: 28 September 2023, Interactive Graphics and Data Analysis, Antony Unwinhttps://www.auckland.ac.nz/en/science/about-the-faculty/department-of-statistics/ihaka-lecture-series.html

Examples

if (require("sf", quietly=TRUE)) {td <- tempdir()xx <- as(sf::st_read(system.file("shape/nc.shp", package="sf")[1], quiet=TRUE), "Spatial")sp2Mondrian(xx, file=file.path(td, "sids1.txt"))}

change feature IDs in spatial objects

Description

When the feature IDs need to be changed in SpatialLines* or SpatialPolygons* objects, these methods may be used. The new IDs should be a character vector of unique IDs of the correct length.

Methods

obj = "SpatialLines", x = "character"

replace IDs in a SpatialLines object

obj = "SpatialLinesDataFrame", x = "character"

replace IDs in a SpatialLinesDataFrame object

obj = "SpatialPolygons", x = "character"

replace IDs in a SpatialPolygons object

obj = "SpatialPolygonsDataFrame", x = "character"

replace IDs in a SpatialPolygonsDataFrame object

Note

It is usually sensible to keep a copy of the original feature IDs in the object, but this should be done by the user.

Author(s)

Roger Bivand

Examples

## Not run: if(require(sf)) {xx <- as(st_read(system.file("shape/nc.shp", package="sf")[1]), "Spatial")row.names(xx) <- as.character(xx$"FIPSNO")row.names(as(xx, "data.frame"))xx1 <- spChFIDs(xx, as.character(xx$CNTY_ID))row.names(as(xx1, "data.frame"))}## End(Not run)

Euclidean or Great Circle distance between points

Description

The function returns a vector of distances between a matrix of 2D points, first column longitude, second column latitude, and a single 2D point, using Euclidean or Great Circle distance (WGS84 ellipsoid) methods.

Usage

spDistsN1(pts, pt, longlat = FALSE)spDists(x, y = x, longlat = FALSE, segments = FALSE, diagonal = FALSE)

Arguments

Value

spDistsN1 returns a numeric vector of distances in the metric of the points if longlat=FALSE, or in kilometers if longlat=TRUE.

spDists returns a full matrix of distances in the metric of the points if longlat=FALSE, or in kilometers if longlat=TRUE; it usesspDistsN1 in case points are two-dimensional. In case ofspDists(x,x), it will compute all n x n distances, not the sufficient n x (n-1).

Note

The function can also be used to find a local kilometer equivalent to a plot scaled in decimal degrees in order to draw a scale bar.

Author(s)

Roger Bivand, Edzer Pebesma

References

http://www.abecedarical.com/javascript/script_greatcircle.html

See Also

is.projected

Examples

ll <- matrix(c(5, 6, 60, 60), ncol=2)km <- spDistsN1(ll, ll[1,], longlat=TRUE)zapsmall(km)utm32 <- matrix(c(276.9799, 332.7052, 6658.1572, 6655.2055), ncol=2)spDistsN1(utm32, utm32[1,])dg <- spDistsN1(ll, ll[1,])dgdg[2]/km[2]data(meuse)coordinates(meuse) <- c("x", "y")res <- spDistsN1(meuse, meuse[1,])summary(res)p1 = SpatialPoints(cbind(1:3, 1:3))spDists(p1)spDists(p1, p1)spDists(p1, p1, diagonal = TRUE)try(spDists(p1, p1, segments = TRUE))spDists(p1, segments = TRUE)p2 = SpatialPoints(cbind(5:2, 2:5))spDists(p1, p2)try(spDists(p1, p2, diagonal = TRUE)) # failstry(spDists(p1, p2, segments = TRUE)) # fails# longlat points:proj4string(p1) = "+proj=longlat +ellps=WGS84"proj4string(p2) = "+proj=longlat +ellps=WGS84"is.projected(p1)is.projected(p2)spDists(p1)spDists(p1, p1)spDists(p1, p1, diagonal = TRUE)spDists(p1, p2)try(spDists(p1, p2, diagonal = TRUE)) # failsspDists(p1, p2[1:length(p1),], diagonal = TRUE)spDists(p1, segments = TRUE)spDists(p1[0],p2[0],diagonal=TRUE)spDists(p1[0])p1 = SpatialPoints(cbind(1:3, 1:3, 1:3))spDists(p1)spDists(p1, p1)try(spDists(p1, p1, diagonal = TRUE))try(spDists(p1, p1, segments = TRUE))try(spDists(p1, segments = TRUE))p2 = SpatialPoints(cbind(5:2, 2:5, 3:6))spDists(p1, p2)try(spDists(p1, p2, diagonal = TRUE)) # failstry(spDists(p1, p2, segments = TRUE)) # fails

spTransform for map projection and datum transformation

Description

spTransform for map projection and datum transformation

Usage

spTransform(x, CRSobj, ...)

Arguments

Value

object with coordinates transformed to the new coordinate referencesystem.

Note

Packagesf provides the methods doing actual transformation.

Plot methods for spatial data with attributes

Description

Lattice (trellis) plot methods for spatial data with attributes

Usage

spplot(obj, ...)spplot.grid(obj, zcol = names(obj), ..., names.attr, scales = list(draw = FALSE), xlab = NULL, ylab = NULL, aspect = mapasp(obj,xlim,ylim), panel = panel.gridplot, sp.layout = NULL, formula, xlim = bbox(obj)[1, ], ylim = bbox(obj)[2, ], checkEmptyRC = TRUE, col.regions = get_col_regions())spplot.polygons(obj, zcol = names(obj), ..., names.attr, scales = list(draw = FALSE), xlab = NULL, ylab = NULL, aspect = mapasp(obj,xlim,ylim), panel = panel.polygonsplot, sp.layout = NULL, formula, xlim = bbox(obj)[1, ], ylim = bbox(obj)[2, ], col.regions = get_col_regions())spplot.points(obj, zcol = names(obj), ..., names.attr, scales = list(draw = FALSE), xlab = NULL, ylab = NULL, aspect = mapasp(obj,xlim,ylim), panel = panel.pointsplot, sp.layout = NULL, identify = FALSE, formula, xlim = bbexpand(bbox(obj)[1, ], 0.04), ylim = bbexpand(bbox(obj)[2, ], 0.04), edge.col = "transparent", colorkey = FALSE, col.regions = get_col_regions())mapLegendGrob(obj, widths = unit(1, "cm"), heights = unit(1, "cm"),fill = "black", just = "right")sp.theme(set = FALSE, regions = list(col = bpy.colors(100)), ...)layout.north.arrow(type = 1)layout.scale.bar(height = 0.05)spplot.locator(n = 512, type = "n", ...)set_col_regions(value)get_col_regions()

Arguments

Value

spplot returns a lattice plot of class "trellis", if you fail to "see" it,explicitly callprint(spplot(...)). Ifidentify is TRUE,the plot is plotted and the return value is a vector with row names ofthe selected points.

spplot.locator returns a matrix with identified point locations;usetrellis.focus first to focus on a given panel.

get_col_regions returns the default value forcol.regions

Methods

obj = "SpatialPixelsDataFrame"

seespplot

obj = "SpatialGridDataFrame"

seespplot

obj = "SpatialPolygonsDataFrame"

seespplot

obj = "SpatialLinesDataFrame"

seespplot

obj = "SpatialPointsDataFrame"

seespplot

Note

Missing values in the attributes are (currently) not allowed.

spplot.grid,spplot.polygons andspplot.points are S4methods forspplot; seespplot-methods.

Useful arguments that can be passed as... are:

layout

integer; for the layout of panels (cols,rows)

pretty

logical; choose colour breaks at pretty numbers?

at

specify at which values colours change

as.table

logical; start drawing panels upper-left insteadof lower-left

page

to add marks to each plotted page

for useful values see the appropriate documentation ofxyplot(in case of points), andlevelplot (otherwise).

Ifobj is of SpatialPointsDataFrame, the following options areuseful to pass:

key.space

character: "bottom", "right", "left" or "right" to denotekey location, or list: see argument key in the help forxyplot whatthe options are

legendEntries

character; array with key legend (text) entries; suitable defaults obtained from data

cuts

number of cuts, or, for objects of classSpatialPointsDataFrame only, the actual cuts to use

do.log

logical; if TRUE use log-linear scale to divide range in equal cuts,else use a linear scale ifcuts is only number of cuts

pch

integer; plotting character to use; defaults to 16 if fill is TRUE, else 1

cex

numeric; character expansion, proportional to default value of 1

fill

logical; use filled circles?

layout.north.arrow andlayout.scale.bar can be usedto set a north arrow or scale bar.

Thesp.layout argument is either a single layout item, or a listwith one or more layout items. A layout item is one of

• a list with one or moreSpatial* objects, along withstyle arguments likecol,lty,pch,fill etc.

• a list with its first argument the layout function orthe name of the layout function to be called:sp.points forSpatialPoints,sp.polygons for SpatialPolygons object,sp.linesfor a SpatialLines object, andsp.text for text to place. Thesecond argument contains the object (or text) to be plotted; remainingarguments are passed to the correspondingpanel.* functions.

The order of items insp.layout matters; objects are drawn in theorder they appear. With respect toobj, default plot order andprecedence ofsp.layout items is as follows: for points andlines,sp.layout items are drawn over (after)obj; forgrids and polygons,sp.layout items are drawn behind (before)obj. Transparency may further help making multiple thingsvisible. Adding afirst argument to a layout item overrides itsdefault plotting order with respect toobj:

Special control elements ofsp.layout items:

first

logical; should the layout item be drawn beforetheobj (TRUE), or after (FALSE)? This overridesthe default order (points and lines in front, polygons and grids behind).

which

integer; controls to which panel a layoutitem should be added. Ifwhich is present in the main,top-level list it applies to all layout items; in sub-lists withlayout items it denotes the (set of) panel(s) in which the layoutitem should be drawn. Without awhich item, layout itemsare drawn in each panel.

sp.theme returns a lattice theme; use, after loading packagelattice, the commandtrellis.par.set(sp.theme())after a device is opened or changed to make this work. Currently, this onlysets the colors tobpy.colors.

If the attributes to be plotted are of type factor, spplot triesto create a legend that reflects this. In this case, the color ramppassed needs to be of the same length as the number of factor levels.The factor levels are derived from the first map; subsequent factorswith different factor levels result in an error.

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

References

https://edzer.github.io/sp/

See Also

xyplot,levelplot,panel.identify to identify objects

Examples

library(lattice)trellis.par.set(sp.theme()) # sets bpy.colors() rampdemo(meuse, ask = FALSE, echo = FALSE)l2 = list("SpatialPolygonsRescale", layout.north.arrow(), offset = c(181300,329800), scale = 400)l3 = list("SpatialPolygonsRescale", layout.scale.bar(), offset = c(180500,329800), scale = 500, fill=c("transparent","black"))l4 = list("sp.text", c(180500,329900), "0")l5 = list("sp.text", c(181000,329900), "500 m")spplot(meuse, c("ffreq"), sp.layout=list(l2,l3,l4,l5), col.regions= "black", pch=c(1,2,3), key.space=list(x=0.1,y=.95,corner=c(0,1)))spplot(meuse, c("zinc", "lead"), sp.layout=list(l2,l3,l4,l5, which = 2),key.space=list(x=0.1,y=.95,corner=c(0,1)))# plotting factors:meuse$f = factor(sample(letters[6:10], 155, replace=TRUE),levels=letters[1:10])meuse$g = factor(sample(letters[1:5], 155, replace=TRUE),levels=letters[1:10])spplot(meuse, c("f","g"), col.regions=bpy.colors(10))if (require(RColorBrewer)) {spplot(meuse, c("ffreq"), sp.layout=list(l2,l3,l4,l5),col.regions=brewer.pal(3, "Set1"))}meuse.grid$g = factor(sample(letters[1:5], 3103, replace=TRUE),levels=letters[1:10])meuse.grid$f = factor(sample(letters[6:10], 3103, replace=TRUE),levels=letters[1:10])spplot(meuse.grid, c("f","g"), col.regions=bpy.colors(10))# example modifying colorkey for points:spplot(meuse["dist"], colorkey = list(right = list( # see ?levelplot in package trellis, argument colorkey:fun = draw.colorkey, args = list(key = list(at = seq(0, 1, .1), # colour breakscol = bpy.colors(11), # colourslabels = list(at = c(0, .2, .4, .6, .8, 1), labels = c("0x", "20x", "40x", "60x", "80x", "100x")))))))l6 = list(meuse.grid["dist"], col = grey(seq(.5,.9,length.out=10)))spplot(meuse, c("zinc", "lead"), sp.layout = l6)spplot(meuse, c("zinc", "lead"), sp.layout = list(meuse.grid, meuse.riv, col = 'grey'))#  Custom legend placement, taken from # http://stackoverflow.com/questions/29344692/custom-placement-of-spplot-legend-in-the-maps <- spplot(meuse.grid[,'dist'], colorkey = list(space = "left", height = 0.4))args <- s$legend$left$args$key## Prepare list of arguments needed by `legend=` argument (as described in ?xyplot)library(lattice) # draw.colorkeylegendArgs <- list(fun = draw.colorkey,                   args = list(key = args),                   corner = c(0.05,.75))## Call spplot() again, this time passing in to legend the arguments## needed to print a color keyspplot(meuse.grid[,'dist'], colorkey = FALSE,       legend = list(inside = legendArgs))

sample point locations in (or on) a spatial object

Description

sample point locations within a square area, a grid,a polygon, or on a spatial line, using regular or random samplingmethods; the methods used assume that the geometry used is not spherical, so objects should be in planar coordinates

Usage

spsample(x, n, type, ...)makegrid(x, n = 10000, nsig = 2, cellsize, offset = rep(0.5, nrow(bb)),pretty = TRUE)

Arguments

Value

an object of classSpatialPoints-class. The number ofpoints is only guaranteed to equaln when sampling is done in asquare box, i.e. (sample.Spatial). Otherwise, the obtained numberof points will have expected valuen.

Whenx is of a class deriving fromSpatial-class for whichnospsample-methods exists, sampling is done in the bounding boxof the object, usingspsample.Spatial. An overlay usingover may be necessary to select the features inside the geometryafterwards.

Sampling type"nonaligned" is not implemented for line objects.

Some methods may return NULL if no points could be successfully placed.

makegrid makes a regular grid that coversx; whencellsize is not given it derives one from the number of gridpoints requested (approximating the number of cells). It tries tochoose pretty cell size and grid coordinates.

Methods

x = "Spatial"

sample in the bbox ofx

x = "Line"

sample on a line

x = "Polygon"

sample in a Polygon

x = "Polygons"

sample in a Polygons object, consisting of possiblymultiple Polygon objects (holes must be correctly defined, usecheckPolygonsHoles if need be)

x = "SpatialPolygons"

sample in an SpatialPolygons object; samplingtakes place over all Polygons objects present, use subsetting to varysampling intensity (density); holes must be correctly defined, usecheckPolygonsHoles if need be

x = "SpatialGrid"

sample in an SpatialGrid object

x = "SpatialPixels"

sample in an SpatialPixels object

Note

If anPolygon-class object has zero area (i.e. is a line),samples on this line element are returned. If the area is very closeto zero, the algorithm taken here (generating points in a squarearea, selecting those inside the polygon) may be very resourceintensive. When numbers of points per polygon are small andtype="random", the number searched for is inflated to ensure hits,and the points returned sampled among these.

The following two arguments can be further specified:

nclusters Number of clusters (strata) to sample from.

iter(default = 4) number of times to try to place sample pointsin a polygon before giving up and returning NULL - this may occur whentrying to hit a small and awkwardly shaped polygon in a large boundingbox with a small number of points

Author(s)

Edzer Pebesma,edzer.pebesma@uni-muenster.de

References

Chapter 3 in B.D. Ripley, 1981. Spatial Statistics, Wiley

Fibonacci sampling: Alvaro Gonzalez, 2010. Measurement of Areas on aSphere Using Fibonacci and Latitude-Longitude Lattices. MathematicalGeosciences 42(1), p. 49-64

See Also

over,point.in.polygon,sample

Examples

data(meuse.riv)meuse.sr = SpatialPolygons(list(Polygons(list(Polygon(meuse.riv)), "x")))plot(meuse.sr)points(spsample(meuse.sr, n = 1000, "regular"), pch = 3)plot(meuse.sr)points(spsample(meuse.sr, n = 1000, "random"), pch = 3)plot(meuse.sr)points(spsample(meuse.sr, n = 1000, "stratified"), pch = 3)plot(meuse.sr)points(spsample(meuse.sr, n = 1000, "nonaligned"), pch = 3)plot(meuse.sr)points(spsample(meuse.sr@polygons[[1]], n = 100, "stratified"), pch = 3, cex=.5)data(meuse.grid)gridded(meuse.grid) = ~x+yimage(meuse.grid)points(spsample(meuse.grid,n=1000,type="random"), pch=3, cex=.5)image(meuse.grid)points(spsample(meuse.grid,n=1000,type="stratified"), pch=3, cex=.5)image(meuse.grid)points(spsample(meuse.grid,n=1000,type="regular"), pch=3, cex=.5)image(meuse.grid)points(spsample(meuse.grid,n=1000,type="nonaligned"), pch=3, cex=.5)fullgrid(meuse.grid) = TRUEimage(meuse.grid)points(spsample(meuse.grid,n=1000,type="stratified"), pch=3,cex=.5)

rearrange data in SpatialPointsDataFrame or SpatialGridDataFrame for plotting with spplot (levelplot/xyplot wrapper)

Description

rearrange SpatialPointsDataFrame for plotting with spplot or levelplot

Usage

spmap.to.lev(data, zcol = 1:n, n = 2, names.attr)## S3 method for class 'SpatialPointsDataFrame'stack(x, select, ...)## S3 method for class 'SpatialGridDataFrame'stack(x, select, ...)

Arguments

Value

spmap.to.lev returns a data frame with the following elements:

stack is an S3 method: it return a data.frame with a columnvalues that has the stacked coordinates and attributes, and acolumnind that indicates the variable stacked; it alsoreplicates the coordinates.

See Also

spplot,levelplot, andstack

Examples

library(lattice)data(meuse.grid) # data framecoordinates(meuse.grid) = c("x", "y") # promotes to SpatialPointsDataFramemeuse.grid[["idist"]] = 1 - meuse.grid[["dist"]] # add variable# the following is made much easier by spplot:levelplot(z~x+y|name, spmap.to.lev(meuse.grid, z=c("dist","idist"), names.attr =c("distance", "inverse of distance")), aspect = "iso")levelplot(values~x+y|ind, as.data.frame(stack(meuse.grid)),aspect = "iso")gridded(meuse.grid) = TRUElevelplot(z~x+y|name, spmap.to.lev(meuse.grid, z=c("dist","idist"), names.attr =c("distance", "inverse of distance")), aspect = "iso")levelplot(values~x+y|ind, as.data.frame(stack(meuse.grid)), asp = "iso")

Compute surface area of a digital elevation model.

Description

It is often said that if Wales was flattened out it would havean area bigger than England. This function computes the surfacearea of a grid of heights taking into account the sloping natureof the surface.

Usage

surfaceArea(m, ...)surfaceArea.matrix(m, cellx = 1, celly = 1, byCell = FALSE)

Arguments

Value

Either a single value of the total area if byCell=FALSE, or a matrixthe same shape as m of individual cell surface areas ifbyCell=TRUE. In this case, the sum of the returned matrix should bethe same value as that which is returned if byCell=FALSE.

Missing values (NA) in the input matrix are allowed. They will producean NA in the output matrix for byCell=TRUE, and contribute zero to thetotal area. They also have an effect on adjacent cells - see codecomments for details.

Methods

obj = "matrix"

takes a matrix as input, requires cellx and celly to be set

obj = "SpatialGridDataFrame"

takes an object of classSpatialGridDataFrame as input, and retrieves cellx and celly from this

obj = "SpatialPixelsDataFrame"

takes an object of classSpatialPixelsDataFrame as input, and retrieves cellx and celly from this

Author(s)

Barry Rowlingson <b.rowlingson@lancaster.ac.uk>, integration in sp EdzerPebesma.

References

Calculating Landscape Surface Area from Digital Elevation Models, Jeff S. JennessWildlife Society Bulletin, Vol. 32, No. 3 (Autumn, 2004), pp. 829-839

Examples

surfaceArea(volcano)image(surfaceArea(volcano,byCell=TRUE))data(meuse.grid)gridded(meuse.grid) = ~x+yimage(surfaceArea(meuse.grid["dist"], byCell=TRUE))surfaceArea(meuse.grid["dist"])

find point pairs with equal spatial coordinates

Description

find point pairs with equal spatial coordinates

Usage

 zerodist(obj, zero = 0.0, unique.ID = FALSE, memcmp = TRUE) zerodist2(obj1, obj2, zero = 0.0, memcmp = TRUE) remove.duplicates(obj, zero = 0.0, remove.second = TRUE, memcmp = TRUE)

Arguments

Value

zerodist andzerodist2 return a two-column matrixwith in each row pairs of row numbers with identical coordinates;a matrix with zero rows is returned if no such pairs are found. Forzerodist, row number pairs refer to row pairs inobj. Forzerodist2, row number pairs refer to rows inobj andobj2, respectively.remove.duplicates removes duplicateobservations if present, and else returnsobj.

Note

When using kriging, duplicate observations sharing identicalspatial locations result in singular covariance matrices.This function may help identify and remove spatial duplices.The full matrix with all pair-wise distances is not stored; thedouble loop is done at the C level.

Whenunique.ID=TRUE is used, an integer index is returned. sp1.0-14 returned the highest index, sp 1.0-15 and later return thelowest index.

Whenzero is 0.0 andmemcmp is notFALSE,zerodist usesmemcmp to evaluate exact equality ofcoordinates; there may be cases where this results in a differentevaluation compared to doing the double arithmetic of computingdistances.

Examples

data(meuse)summary(meuse)# pick 10 rowsn <- 10ran10 <- sample(nrow(meuse), size = n, replace = TRUE)meusedup <- rbind(meuse, meuse[ran10, ])coordinates(meusedup) <- c("x", "y")zd <- zerodist(meusedup)sum(abs(zd[1:n,1] - sort(ran10))) # 0!# remove the duplicate rows:meusedup2 <- meusedup[-zd[,2], ]summary(meusedup2)meusedup3 <- subset(meusedup, !(1:nrow(meusedup) %in% zd[,2]))summary(meusedup3)coordinates(meuse) <- c("x", "y")zerodist2(meuse, meuse[c(10:33,1,10),])