I just made a simple subtraction between two raster layers and got the error:

Traceback (most recent call last): File "C:/Users/user/.qgis2/python/plugins\raster_transparency\rastertransparency.py", line 150, in layerChanged maxValue = int(stat.maximumValue) OverflowError: cannot convert float infinity to integer

Both layers are Geotiff 32 bit pixel depth and floating point pixel type.

Is this a bug in the raster calculator or does anyone have suggestions to why I cannot subtract the two layers? Running QGIS 2.10.1

  • In your output layer you have an infinity symbol after these calculations. Python tries to perform int(infinity) ant it can't be done. – dmh126 Nov 17 '15 at 12:04
  • hmm okay, thanks for your answer! Is that something I can change manually? I also just found out that QGIS say the layer min-max is -1.66 - 392.71 gdal info say its -6.7 - 562 (which is right). I dont understand wy QGIS show the wrong value. If I load the raster to ArcMap the right values are shown – geogrow Nov 17 '15 at 12:12
  • Ok so about QGIS displaying wrong Min/max is bc it calculates by default is 2% - 98%, see the 'Cumulative count cut' option in the 'Load min/max values' section of the dialog box. – geogrow Nov 17 '15 at 12:20
  • In C:/Users/user/.qgis2/python/plugins\raster_transparency\rastertransparency.py you can try to manually change this line maxValue = int(stat.maximumValue) to something like that maxValue = stat.maximumValue. I think it is qgis function bug, wrong band statistics. – dmh126 Nov 17 '15 at 12:33
  • Thanks for your suggestion! I tried what you said. Replaced maxValue = int(stat.maximumValue) with maxValue = stat.maximumValue. Did the same with the minimumValue. Unfortunately it came back with the same error but displaying maxValue = stat.maximumValue instead. I know some people in my office has worked with the same tif file and done some raster calc with it in QGIS so I wonder if I have a bug in my program – geogrow Nov 17 '15 at 13:34

I was not able to use the built in raster calculator. However using the SAGA raster calculator in the processing toolbox did the job.

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