This program may be especially useful when sampling for cross validation of interpolations whose output is a raster map.
The output points will have the easting and northing of the input points. The input category value is used. The input attribute, raster value and difference is written to output.
When NULL values are encountered for a cell, zero value is used instead. In these cases, more acurrate results may be obtained by using the default nearest neighbor comparisons.
This program may not work properly with lat-long data when the -BC flags are used.
When interpolation is done (i.e., the -BC flags are used), values are assumed to be located at the centroid of grid cells. Therefore, current resolution settings are important.
Updated for GRASS 5.0 by Eric G. Miller
Updated for GRASS 5.7 by Radim Blazek
Last changed: $Date$