arcpullr (version 0.3.2)

match_legend_colors: Match colors in SpatRaster coltab to the provided legend values

Description

Colors provided by the legend do not always correspond exactly with the colors in the coltab of a SpatRaster object. They are usually pretty close, though, so this function finds the closest colors, maps them to the appropriate colors in the Raster* object, and applies that to the legend.

Usage

match_legend_colors(legend, raster_cols)

Value

A raster_legend object with corrected colors to match those in x

Arguments

legend

An object of class raster_legend as returned by get_layer_legend

raster_cols

The colortable from a SpatRaster object. Use the first item in the list

Details

Raster colors in x are mapped to those in legend by converting the RGB hexadecimal values to a 3D vector of values for red, green and blue. The closest values are then assigned using 3D Pythagorean theorem to compute the distance among all colors. The minimum distance in three dimensional space is the color in x that gets mapped to the appropriate color in legend.

Examples

if (FALSE) {
wi_landcover <- get_map_layer(wi_landcover_url, wis_poly)
legend <- get_layer_legend(wi_landcover_url)
new_legend <- match_legend_colors(legend, wi_landcover_url)
}