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Using QGis 2.16.3, I'm trying to perform a multi stage raster calculation. Trying to do the whole calculation using brackets to subset parts causes a memory issue; however running a raster calculation on the output of a previous raster calculation results in all pixels incorrectly taking on the same value.

For example:

(0.56*"Band3@1")+2

Returns a .tif file with pixels ranging from 402.922 to 4863.86 whereas

0.56*"Band3@1"

saved as Band3_R.tif and then using a second raster calculation of

"Band3_R@1"+2

returns a .tif file with all pixels being 2.

It is the same regardless of what operation I attempt on the output (addition, subtraction, multiplication or division).

Can you run a raster calculation on the output of a raster calculation? If so, how?

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  • Perhaps a bug? I do not have this problem with QGIS 2.18.2 for Win7 64-bit. Could you try installing a newer version?
    – Joseph
    Oct 11, 2017 at 9:20
  • Must have been a bug - installed QGIS 2.18.13 and now works. Thanks @Joseph. Didn't even consider that as the cause - still rather new to GIS Oct 12, 2017 at 0:49
  • Nice one! Glad you got it working :)
    – Joseph
    Oct 12, 2017 at 9:14

1 Answer 1

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It must have been a bug - Updating to QGIS 2.18.13 solved the problem.

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