topic Raster Calculator "con" statement issues in ArcGIS Spatial Analyst Questions

Raster Calculator "con" statement issues

SamuelJantz — Tue, 12 Oct 2010 14:59:28 GMT

Hi all,

I'm trying put together a string of con statements using two images in order to create one new image. Ex:
con([B1.tif] == 90, [B2.tif]-20, [B2.tif])
con([B1.tif] == 75, [B2.tif]-10, [B2.tif])

The calculator executes the statements, but produces one new image for both statements. Is there any way of writing the syntax such that only one image is created from a string of con statements?

many thanks,

sam

Re: Raster Calculator "con" statement issues

DanPatterson_Retired — Tue, 12 Oct 2010 17:05:11 GMT

to address your specific question, con statements can be nested, however, this may prove less than satisfactory if you have more than 2 to next
con([B1.tif] == 90, [B2.tif]-20, (con([B1.tif] == 75, [B2.tif]-10, [B2.tif]))

Re: Raster Calculator "con" statement issues

SamuelJantz — Wed, 13 Oct 2010 01:57:26 GMT

Well, I will need to add many more conditions; probably around 30. However, I gave the statement a test run with just two conditions and kept getting the error that it could not save the raster dataset with output format GRID. Is there another method that would be less cumbersome than using con?

thanks again,

sam

Re: Raster Calculator "con" statement issues

DanPatterson_Retired — Wed, 13 Oct 2010 07:36:10 GMT

if this is some form of reclassification, have a look at this thread
http://forums.arcgis.com/threads/4126-using-RECLASS-in-Raster-calculator

Re: Raster Calculator "con" statement issues

SamuelJantz — Thu, 14 Oct 2010 18:50:28 GMT

Yep, that did it! Thanks for your help!

Re: Raster Calculator "con" statement issues

CoreyAnco — Thu, 28 Oct 2010 18:39:09 GMT

Hi I have found a roundabout way to my issue but I wanted to see if anyone else has been encountering this and wanted to know why IT WAS HAPPENING.

Every I ran the statement below in Raster Calculator I kept getting an error message (also displayed below). However, this exact statement would run perfectly in 9.3. Any suggestions as to why this error keeps popping up?

Thank you for your time.

Statement in Raster Calculator:

Con((("%elev%" > 1500 & "%elev%" < 2500) & ("%mat%" > 165 & "%mat%" < 215) & ("%slope%" > 1800 & "%slope%" < 10500) & ("%pcp_drym%" > 15 & "%pcp_drym%" < 24) & ("%pcp_wetm%" > 150 & "%pcp_wetm%" < 220)), 1, 0)

Error Received upon Execution:

ERROR 000539: Error running expression: rcexec() <type 'exceptions.ValueError'>: The truth value of a raster is ambiguous. Failed to execute (Raster Calculator).

Re: Raster Calculator "con" statement issues

RichardRupp — Thu, 04 Nov 2010 16:21:15 GMT

Hi,
I ran into the same situation. You need some additional parentheses (see below).
Regards, Rick

Con(((("%elev%" > 1500) & ("%elev%" < 2500)) & (("%mat%" > 165) & ("%mat%" < 215)) & (("%slope%" > 1800) & ("%slope%" < 10500)) & (("%pcp_drym%" > 15) & ("%pcp_drym%" < 24)) & (("%pcp_wetm%" > 150) & ("%pcp_wetm%" < 220))), 1, 0)

Error Received upon Execution:

ERROR 000539: Error running expression: rcexec() <type 'exceptions.ValueError'>: The truth value of a raster is ambiguous. Failed to execute (Raster Calculator).

Re: Raster Calculator "con" statement issues

CoreyAnco — Wed, 15 Dec 2010 15:46:43 GMT

Rick,

Thank you for the reply. I went aroud it by running several different con statements and then using plus to add th evariables together and then another con statement to isolate the combined variables for each environmental factor. I am relieved to know that just adding one more set of parentheses relieves this issue.

Thank you for the reply, I will be sure to pass along the helpful information.

All the best,
Corey

topic Raster Calculator &quot;con&quot; statement issues in ArcGIS Spatial Analyst Questions

Raster Calculator "con" statement issues

Re: Raster Calculator "con" statement issues

Re: Raster Calculator "con" statement issues

Re: Raster Calculator "con" statement issues

Re: Raster Calculator "con" statement issues

Re: Raster Calculator "con" statement issues

Re: Raster Calculator "con" statement issues

Re: Raster Calculator "con" statement issues

topic Raster Calculator "con" statement issues in ArcGIS Spatial Analyst Questions