terra (version 1.1-17)

cells: Get cell numbers

Description

Get the cell numbers covered by a SpatVector or SpatExtent. Or that match values in a vector; or all non NA values.

Usage

# S4 method for SpatRaster,missing
cells(x, y)
# S4 method for SpatRaster,numeric
cells(x, y)
# S4 method for SpatRaster,SpatVector
cells(x, y, method="simple", weights=FALSE, touches=is.lines(y))
# S4 method for SpatRaster,SpatExtent
cells(x, y)

Arguments

x

SpatRaster

y

SpatVector, SpatExtent, 2-column matrix representing points, numeric representing values to match, or missing

method

character. Method for getting cell numbers for points. The default is "simple", the alternative is "bilinear". If it is "bilinear", the four nearest cells and their weights are returned

weights

logical. If TRUE and y has polygons, the fraction of each cell that is covered is returned as well

touches

logical. If TRUE, values for all cells touched by lines or polygons are extracted, not just those on the line render path, or whose center point is within the polygon. Not relevant for points

Value

numeric vector or matrix

Examples

# NOT RUN {
r <- rast(ncols=10, nrows=10)
values(r) <- 1:ncell(r)
r[c(1:25, 31:100)] <- NA
r <- ifel(r > 28, r + 10, r)

# all cell numbers of cells that are not NA
cells(r)

# cell numbers that match values
x <- cells(r, c(28,38))
x$lyr.1

# cells for points
m <- cbind(x=c(0,10,-30), y=c(40,-10,20))
cellFromXY(r, m)

v <- vect(m)
cells(r, v)
cells(r, v, method="bilinear")

# cells for polygons
#f <- system.file("ex/lux.shp", package="terra")
#v <- vect(f)
#r <- rast(v)
#cv <- cells(r, v) 
# }