Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I am trying to build a model with Sextante modeler and the r.mapcalculator algorithm but when I run the model I get the error message:

‘Could not load layer: ‘….’Check sextant log to look for errors in algorithm execution.’

The Sextant Log reads:

   /0607_Processed Images/0607_b4_warp","H:/NDSI/MODIS/20120607_SurfaceReflectance
      /0607_Processed Images/0607_band6_warp","H:/NDSI/MODIS/test/NDSI")

The algorithm I have put into r.mapcalculator is a basic algorithm to calculate NDSI for snowcover analysis:

e.g. (amap-bmap)/(amap+bmap)

amap = band 4

bmap= band 6

I have tried on different computers as well as only using the r.mapcalculator through the Sextante Toolbox. Is there a different calculator I can use in my model? Is there a different way I should write out my algorithm?

share|improve this question

Enable the GRASS logging (in the SEXTANTE configuration dialog, under GRASS), and then have a look at the log, but in the "Info" branch. You should have there a "GRASS console output" entry. That will tell you more about what is happening when you call grass.

Post it here so we can help you with it.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.