rasterize: Rasterize vector data
In terra: Spatial Data Analysis

rasterize

R Documentation

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, sum=FALSE, cover=FALSE, filename="", overwrite=FALSE, wopt=list())

## S4 method for signature 'matrix,SpatRaster'
rasterize(x, y, values=1, fun, ..., background=NA, 
	update=FALSE, 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`	function, summarizing function that returns a single number; for when there are multiple points in one cell. For example `mean`, `length` (to get a count), `min` or `max`. Only used if `x` consists of points
`...`	additional arguments passed to `fun` if `x` has point geometries
`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
`sum`	logical. If `TRUE`, the values of overlapping geometries are summed instead of replaced; and `background` is set to zero. Only used if `x` does not consists of points
`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)
`filename`	character. Output filename
`overwrite`	logical. If `TRUE`, `filename` is overwritten
`wopt`	list with additional arguments for writing files as in `writeRaster`

Value

SpatRaster

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)

terra documentation built on Jan. 17, 2023, 5:18 p.m.