Normalize Raster Values by Polygon Regions

This function normalizes raster values within each polygon region by dividing the values by the total sum for that region. This creates proportional values that sum to 1 within each polygon.

Usage

normalize_raster_by_polygon(raster, shp, id_col)

Arguments

raster

A SpatRaster object containing the values to be normalized

shp

A spatial vector (SpatVector) containing the polygon regions

id_col

Character string specifying the column name in shp that contains the region identifiers

Value

A SpatRaster object with normalized values where the sum within each polygon region equals 1

Details

The function processes each polygon region separately by:

1. Masking the raster to the region boundaries

2. Calculating the total sum for the region

3. Dividing all values in that region by the total The results are then mosaicked back together into a single raster.

Examples

if (FALSE) { # \dontrun{
normalized <- normalize_raster_by_polygon(
  raster = population_raster,
  shp = admin_boundaries,
  id_col = "region_id"
)
} # }