With the 'r.los' command I've made some tiff raster images from a dem tiff. When I open the raster calculator to do math with the new rasters, the result is always a "nan" raster. From its options I load min/max values and it gives me 1.79769e+308 and -1.79769e+308. I reclassified the 'los' rasters with integer values but no change. I used the clipper to fill no data values with 0, but nothing changed. I saw here a post which said to do the math operations like this "float(los1+los2)" but nothing changed. The "fill no data" command gives me values from 1-255. The "r.fillnuls" command corrupts the results probably because i don't know what value to put in the "Spline" parameters. Do you have any option?
Well I found a solution. I converted all the los tiffs into vector, and then merged them. Finally I converted them again into raster. If there is some less brutal solution I would appreciate it.