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i have a landuse raster data and raster data containing slopes in percentage. i want to assign pixel value as zero which corresponds to slope more than 15%. i tried using 'extract by mask' but i'm unable to get the desired result. is there anyway to solve this?

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up vote 5 down vote accepted

How to do this using Map Algebra is described under the topic of Conditional evaluation with Con in the ArcGIS for Desktop Online Help.

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+1 Another way uses the fact that true results evaluate to 1 and false to 0, whence an expression like ("slope" <= 15) * "landuse" ought to accomplish the same as Con. – whuber Sep 19 '13 at 6:46

Using the Raster Calculator in Whitebox GAT ( you would enter the following line:

[output raster]=IF(([slope]>15),0,[landuse])

I'm sure that ArcGIS has an equivalent statement in its calculator as well.

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