Select values from rasters in a stack based on values in another raster

selectRange() selects values from GRasters in a "stack" based on the values in another "selection" raster. For example, if the stack has three layers (call them A, B, and C), the "selection" raster could have values of 1, 2, or 3 in each cell. The raster that is returned will have values from A wherever the selection raster is 1, B from where it is 2, and C from where it is 3.

Usage

# S4 method for class 'GRaster'
selectRange(x, y)

Arguments

x

A GRaster, typically with more than one layer.

y

A GRaster with integer values. The raster will be rounded if it does not. The values are typically between 1 and the number of layers in x, but wherever they are outside this range, the returned raster will have NA values.

Value

A GRaster.

Examples

if (grassStarted()) {

# Setup
library(terra)

# Example data
madElev <- fastData("madElev")

# Convert a SpatRaster to a GRaster
elev <- fast(madElev)

# Make a stack of various versions of "elev" from which to select from:
x <- c(elev, 10 * elev, ln(elev), -1 * elev)
x

# Make a layer with random numbers between 1 and 4:
fun <- "= round(rand(0.5, 4.5))"
y <- app(elev, fun = fun)

selected <- selectRange(x, y)

}