mbg (version 1.1.0)

build_aggregation_table: Build aggregation table

Description

Build a table to quickly aggregate from pixels to polygons

Usage

build_aggregation_table(polygons, id_raster, polygon_id_field, verbose = FALSE)

Value

data.table with fields:

• polygon_id: Unique polygon identifier

• pixel_id: unique pixel ID from the ID raster

• masked_pixel_id: Index counting only non-NA pixels from the ID raster

• area_fraction: fraction of the pixel area falling within this polygon

• Merged fields from the table of polygons

Arguments

polygons

terra::SpatVector object. Should contain a unique ID field.

id_raster

terra::SpatRaster object. ID raster created by build_id_raster() for the polygons object. Should have the same CRS as polygons and completely cover it.

polygon_id_field

(character(1)) Unique identifier field in polygons.

verbose

(logical(1), default FALSE) Show progress for building aggregation rows for each polygon?

See Also

calculate_pixel_fractions_single_polygon()

Examples

if (FALSE) {
  polygons <- sf::st_read(system.file('extdata/Benin_communes.gpkg', package = 'mbg'))
  id_raster <- build_id_raster(polygons)
  aggregation_table <- build_aggregation_table(
    polygons, id_raster, polygon_id_field = 'commune_code'
  )
}