buffer {terra}

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)

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)

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

Value

Same as x (SpatRaster or SpatVector). For SpatRaster: cells inside the buffers have the value 1.

See Also

distance, elongate

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)

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