Maps of SHAP values, from an importance computed at points of the map.
Source:R/importance.R
importance_map.RdLays the values of dsm_importance()(at = ) back on a grid: each cell
the mean of the points in it. With the points' own grid (from
importance_points()) every point is its own cell; with a coarser
resolution, each cell averages the points it holds.
Arguments
- x
A
dsm_importancefromshap_importance()at map points.- resolution
Cell size of the maps, in the rasters' units; NULL for the points' own grid.
- output_dir
Where to write the GeoTIFFs (shap.tif, one layer per variable; shap_dominant.tif and its legend, shap_dominant.csv; prediction.tif); NULL to only return them.
Value
An importance_map, a list: shap (one layer per variable: the mean
SHAP value of the points in each cell, in the network's units), dominant
(in each cell, the variable with the largest mean |SHAP|, as the number in
legend), legend, prediction (the mean prediction, native units)
and files. The three rasters are packed with terra::wrap(), so the map
survives base::saveRDS(); terra::unwrap() gives each as a SpatRaster.
plot() draws it.
Examples
if (FALSE) { # torch::torch_is_installed()
# \donttest{
run <- example_run() # a small fitted run, made once a session
pts <- importance_points(run$final, run$data, every = 4)
imp <- dsm_importance(run$final, run$data, shap_importance(samples = 10, background = 20),
at = pts, seeds = 42, verbose = FALSE)
m <- importance_map(imp)
plot(m)
# }
}