buffer: Create a buffer around vector geometries or raster patches
In terra: Spatial Data Analysis

buffer

R Documentation

Create a buffer around vector geometries or raster patches

Description

Calculate a buffer around all cells that are not NA in a SpatRaster, or around the geometries of a SpatVector.

SpatRaster cells inside the buffer distance get a value of 1.

Note that the distance unit of the buffer width parameter is meters if the CRS is (+proj=longlat), and in map units (typically also meters) if not.

Usage

## S4 method for signature 'SpatRaster'
buffer(x, width, background=0, filename="", ...)

## S4 method for signature 'SpatVector'
buffer(x, width, quadsegs=10, capstyle="round", 
		joinstyle="round", mitrelimit=NA, singlesided=FALSE)

Arguments

`x`	SpatRaster or SpatVector
`width`	numeric. Unit is meter if `x` has a longitude/latitude CRS, or in the units of the coordinate reference system in other cases (typically also meter). The value should be > 0 if `x` is a SpatRaster. If `x` is a SpatVector, this argument is vectorized, meaning that you can provide a different value for each geometry in `x`; and you can also use the name of a variable in `x` that has the widths
`filename`	character. Output filename
`...`	additional arguments for writing files as in `writeRaster`
`background`	numeric. value to assign to cells outside the buffer. If this value is zero or FALSE, a boolean SpatRaster is returned
`quadsegs`	positive integer. Number of line segments to use to draw a quart circle
`capstyle`	character. One of "round", "square" or "flat". Ignored if `is.lonlat(x)`
`joinstyle`	character. One of "round", "mitre" or "bevel". Ignored if `is.lonlat(x)`
`mitrelimit`	numeric. Place an upper bound on a mitre join to avoid it from extending very far from acute angles in the input geometry. Ignored if `is.lonlat(x)`
`singlesided`	logical. If `TRUE` a buffer is constructed on only one side of each input line. Ignored if `is.lonlat(x)`

Value

Same as x

Examples

r <- rast(ncols=36, nrows=18)
r[500] <- 1
b <- buffer(r, width=5000000) 
plot(b)

v <- vect(rbind(c(10,10), c(0,60)), crs="+proj=merc")
b <- buffer(v, 20)
plot(b)
points(v)

crs(v) <- "+proj=longlat" 
b <- buffer(v, 1500000)
plot(b)
points(v)

terra documentation built on Oct. 13, 2023, 5:08 p.m.