

r.mapcalc - 

r.mapcalc performs arithmetic on \raster\ \map layers\.  New map layers
can be created which are arithmetic expressions involving existing
raster map layers, integer or floating point constants and functions.

The paper 'r.mapcalc: An Algebra for GIS and Image Processing' provides
examples of how some spatial filters commonly used in image processing
can be built using r.mapcalc.

Manual entry for \r.mapcalc\
