rasterize {terra}

Rasterize vector data

Description

Transfer values associated with the geometries of vector data to a raster

Usage

## S4 method for signature 'SpatVector,SpatRaster'
rasterize(x, y, field="", fun, ..., background=NA, touches=FALSE, update=FALSE, 
	cover=FALSE, by=NULL, filename="", overwrite=FALSE, wopt=list())

## S4 method for signature 'matrix,SpatRaster'
rasterize(x, y, values=1, fun, ..., background=NA, update=FALSE, 
	by=NULL, filename="", overwrite=FALSE, wopt=list())

Arguments

x

SpatVector or a two-column matrix (point coordinates)

y

SpatRaster

field

character or numeric. If field is a character, it should a variable name in x. If field is numeric it typically is a single number or a vector of length nrow(x). The values are recycled to nrow(x)

values

typically a numeric vector of length 1 or nrow(x). If the length is below nrow(x) the values will be recycled to nrow(x). Only used when x is a matrix. Can also be a matrix or data.frame

fun

summarizing function for when there are multiple geometries in one cell. For lines and polygons you can only use "min", "max", "mean", "count" and "sum" For points you can use any function that returns a single number; for example mean, length (to get a count), min or max

...

additional arguments passed to fun

background

numeric. Value to put in the cells that are not covered by any of the features of x. Default is NA

touches

logical. If TRUE, all cells touched by lines or polygons are affected, not just those on the line render path, or whose center point is within the polygon. If touches=TRUE, add cannot be TRUE

update

logical. If TRUE, the values of the input SpatRaster are updated

cover

logical. If TRUE and the geometry of x is polygons, the fraction of a cell that is covered by the polygons is returned. This is estimated by determining presence/absence of the polygon in at least 100 sub-cells (more of there are very few cells)

by

character or numeric value(s) to split x into multiple groups. There will be a separate layer for each group returned. If x is a SpatVector, by can be a column number or name. If x is a matrix, by should be a vector that identifies group membership for each row in x

filename

character. Output filename

overwrite

logical. If TRUE, filename is overwritten

wopt

list with additional arguments for writing files as in writeRaster

Value

SpatRaster

See Also

rasterizeGeom, rasterizeWin, mask

Examples

r <- rast(xmin=0, ncols=18, nrows=18)

# generate points
set.seed(1)
p <- spatSample(r, 1000, xy=TRUE, replace=TRUE)

# rasterize points as a matrix
x <- rasterize(p, r, fun=sum)
y <- rasterize(p, r, value=1:nrow(p), fun=max)

# rasterize points as a SpatVector
pv <- vect(p)
xv <- rasterize(pv, r, fun=sum)

# Polygons
f <- system.file("ex/lux.shp", package="terra")
v <- vect(f)
r <- rast(v, ncols=75, nrows=100)
z <- rasterize(v, r, "NAME_2")
plot(z)
lines(v)