topic Re: raster calculator for conditional statement to compare two datasets in ArcGIS Spatial Analyst Questions

raster calculator for conditional statement to compare two datasets

SwamyPati — Tue, 19 Oct 2010 19:06:49 GMT

Hi,
I am trying to compare two raster (grid) datasets and put a condition statement if one is greater than the other take the difference if not no value. is the following statement correct for this?
(out_grid) CON([xgrid]>[ygrid], [xgrid]-[ygrid], 0)

When I tried with this statement, for the first few minutes, task bar shows that it is processing and after it hits 100%, program just freezes. Not sure if this freeze is just GIS taking time or it is not doing anything? So, my next part of the question is how long does this process takes, my datasets are large (3GB)?

Thanks for any suggestions,
Swamy.

Re: raster calculator for conditional statement to compare two datasets

DonovanCameron — Tue, 19 Oct 2010 20:04:42 GMT

3GB = Long Time

Especially if the cell size is relatively small. More rows and columns to process.

When it gets to 100%, get a coffee or whatever it is that tickles your throat. Maybe run it at the end of the day and see what the results are the morning after, if it is freezing once it gets to 100%.

Re: raster calculator for conditional statement to compare two datasets

SwamyPati — Tue, 19 Oct 2010 20:11:00 GMT

Thanks for the response. you are right, I may have to leave it over night and come back and see what it does!
-Swamy.