Valentina wrote: > I tried to calculate the geometric mean with float numbers > for six raster maps, but the result was a map with only one > value: 1.0. > I used the formula: (A*B*C*D*E*F) ^ (1/6), and also: > pow((A*B*C*D*E*F), (1/6)) but I get always the same result: 1.0. > Could somebody help me?
try: pow((A*B*C*D*E*F), (1/6.0)) The result of an integer/integer calculation is an integer, so 0.166667 is truncated to 0 and the result will be x^0, which is always equal to 1. In this manner r.mapcalc just follows what the C programming language does, the quirk is not really specific to r.mapcalc or GRASS. Hamish _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user