Determining average value

[Marilyn Ruiz]

> ... a simple program ... to determine average value for a raster data set.

Steve,

r.average can also do this:

	r.average base=MASK_AREA cover=EVAPORATION_POTENTIAL output=AVE_POTENTIAL

The base map holds the information about the area to be used when
calculating the average.  It is MASK in this example, because that is
the example you described.  It could also have more than two values
(i.e. 0 and 1) and then you could get an average for each of the parts
in the base map. 

The output is a reclass of the base map, with the average held in
the category labels.  To read the label, use r.cats

	r.cats map=AVE_POTENTIAL cats=1

Marilyn Ruiz
ruiz at thales.geog.ufl.edu