I have a raster area map with only coordinate values for each cell, and a
separate raster line map also with only coordinate values for each cell. See
attached .png map.
Using r.mapcalc I want to add either of two values to the area map cells with
all cells in the area below (south) of the line containing one value and all
cells above (north) of the line containing a different value.
If I combine the area and line into a single map, the line disappears
(this happened with the vector versions of the maps), so it seems to me that
the proper approach is to write a r.mapcalc expression that sets cell values
based on their coordinates relative to the line map. Not before having done
anything like this I would appreciate pointers to examples I could use to
learn how to add these values to the area map.
Rich