Feature request: Adding a by argument to rasterize

[sambweber]

Hi,

I was wondering whether it would be possible to incorporate a by = option into rasterize that allows you to rasterize vector data based on some factorial attribute and return a stack with one layer per factor level? It would be really useful in many situations e.g. rasterizing points by month or individual. At the moment I am doing it using a custom function:

rasterize_by(data, raster, by, ...){

rast(lapply(split(data, by), rasterize, y = raster, ...))

}

But the GIS students I teach aren't really aware of nesting and apply functions so it would be great to have it as a simple option in the CRAN version of the package. Apologies if there is already a way of doing this that I have missed!

Thanks,

Sam

[rhijmans]

I have implemented that. Please give it a try. Here is an example for polygons.

library(terra)
f <- system.file("ex/lux.shp", package="terra")
v <- vect(f)
r <- rast(v, ncols=75, nrows=100)
z <- rasterize(v, r, "NAME_2", by="NAME_1")

plot(z, fun=\()lines(v), plg=list(x="topright", cex=.7), mar=1.5, col=rainbow(6))