I would like to create a raster, which represents the weighted mean of a number of SpatRasters per cell, i.e., I want a new raster where for every cell at position [x,y], this cell will have the weighted mean of the input SpatRasters' cells at positions [x,y].
The weights should be applied per whole raster, e.g., if raster_1 has weight 4, raster_2 2 and raster_3 1, then for every cell of the resulting raster: weighted_mean_raster[x,y] = (raster_1[x,y] * 4 + raster_1[x,y] * 2 + raster_1[x,y] * 1) / (4 + 2 + 1)
I am aware of the app function, and I have used it before to create a non-weighted mean raster:
# new raster with the mean of each cell value of the 3 other rasters
mean_raster = app(raster_1, raster_2, raster_3, fun=mean)
However, I cannot get this approach to work when fun=terra::weighted.mean whichever inputs I try to put into "weighted.mean"
Thank you very much in advance for all your help!