[Qgis-user] mathematical functions in raster calculator

[Sergio A Estay]

Dear All,

I am wondering if it is possible to use, in the raster calculator, 
different mathematical functions in that the defined in the raster calc GUI.

By example, using my layer GDD (just positive values) I try this:

exp("GDD at 1") but I obtained just NaN values in the result layer, the 
same with e^"GDD at 1"


Also, if I try something like this:

"GDD at 1"^2 , this worked perfect, but if I try:

2^"GDD at 1" this produced just NaN

Any suggestions will be useful

-- 
Sergio A. Estay
Inst. Ciencias Ambientales y Evolutivas
Universidad Austral de Chile
Casilla 567, Valdivia, Chile
Phone: 5663-293913
http://www.ciencias.uach.cl/instituto/ciencias_ambientales_evolutivas/academicos/sergio-estay.php