1

Used a DEM raster and then used the extract-by-mask feature to shrink it to the shp file I'm working with. However, when I try to get unique values, it gives me the following error message:

"The number of unique values reached the default limitation (>65536). Note the number (65536) should be read from the setting."

I ask because when I loaded up my masked raster (DEM_Mask), I am able to see min-max values of 1685.94-3463. I am trying to use query builder in the conditional tool to filter out areas between values of 2000-2500 (Value <=2000 AND Value >=2500), but see no "Value" field in the query builder. I'm not sure what went wrong or if there are other methods that I'm unaware of.

3

The first error message comes from the fact that your raster is in float, so you have more that 65535 (aka 16bit) possible unique values, but this does not mean that the values is larger than 65535. You should convert your a raster to integer (e.g. with copy raster or with Int(raster) in map algebra tools) if you want to be able to build unique values, but this is not necessary for your problem.

Now, here is the syntax for the conditional statement (in the raster calculator) :

Con( ("raster" >= 2000) and ("raster" <= 2500), 1 , 0)

of course, you can replace 1 (the value if the statement is true) and 0 (the value if the statement is false, by any other value. Also note that "raster" is the name of your raster.

  • Thanks! I used the Int(DEM_mask) and it worked out well! For some reason, forgot about the Float vs integer. I thought I was able to get by with that in the past, but guess I'll make sure my raster values are in INT form next time. – GISFan Jul 9 '14 at 16:36
  • Thanks for posting the raster calculator statement as well. Always been something I've struggled with, since the other tools for conditional seem easier. – GISFan Jul 9 '14 at 16:42

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