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What is the equivalent statement of the following expression in the QGIS raster calculator?

    Con(((Abs("DEM" - "FSMin") > 120) | (Abs("DEM" - "FSMax") > 120)), 1, 0)

I have no problem running this command in ArcMap but as soon as I paste it in QGIS the raster calculator there rejects it.

2 Answers 2

35

You can create a condition by using a little 'trick':

Suppose you have a raster file (layer1) with values below 0 but you want only positive values.

("layer1@1" > 0 )

Is resulting in 1 when it is above 0 and is resulting in 0 when it is below 0.

("layer1@1" > 0 ) * "layer1@1"

When you multiply this with the raster value it will either be 0 or it will be 1 multiplied with the raster value.

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As of QGIS 3.22, the raster calculator supports if statements. Depending on the naming of the layers and raster band numbering, it would be something like

if((abs("DEM@1" - "FSMin@1") > 120) or (abs("DEM@1" - "FSMax@1") > 120), 1, 0)
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