The following errors in ArcMap are preventing me from moving forward:

1) In Raster Calculator using "Aspect": "%DEM_Aspect%" <= 90 or "%DEM_Aspect%" >= 270

ERROR 000539: Error running expression: rcexec() Traceback (most recent call last): File "", line 1, in File "", line 5, in rcexec ValueError: The truth value of a raster is ambiguous. Invalid use of raster with Boolean operator or function. Check the use of parentheses where applicable.

I'm using SRTM1N34W087V2, 11-FEB-00 (Void Filled) raster.

I'm attempting to use ArcMap to accomplish the same results done in the QGIS tutorial Lesson 3: Terrain Analysis.

The lesson is found here: http://manual.linfiniti.com/en/rasters/terrain_analysis.html

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  • I suspect that your question is more likely to attract potential answerers if you can edit it to describe the first step on which are stuck in terms of what you are trying to do in ArcGIS for Desktop rather than referring them to a tutorial at another website to translate. It may be useful background to say that you are trying to translate a QGIS tutorial but your question reads to me like "I got this far, can you finish the rest?"
    – PolyGeo
    Commented Apr 12, 2015 at 21:10
  • Thanks for clarifying that @PolyGeo. I restated my specific problem. This actually leads up to the original one. I didn't realize using Raster Calculator in the step prior (North Facing) was giving an additional error.
    – Jack Bauer
    Commented Apr 12, 2015 at 21:31
  • Thanks for updating but don't forget (from the Tour) that only one question should be asked per question. At the moment you seem to be asking two which would make your question too broad for focussed Q&A. Additional questions to your first can be researched/asked separately.
    – PolyGeo
    Commented Apr 12, 2015 at 21:37
  • I've further updated the picture and limited my questions as well.
    – Jack Bauer
    Commented Apr 12, 2015 at 21:53
  • That's much clearer and more focussed now - thanks!
    – PolyGeo
    Commented Apr 12, 2015 at 21:56

1 Answer 1


The problem with this statement is the parenthesis.. Compound statements need to be enclosed in a 'block':

Con((Condition1) | (Condition2),True_value,False_value)

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The correct syntax for the field calculation is:

Con(("%DEM_Aspect%" <= 90) | ("%DEM_Aspect%" >= 270),1,0)

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