I'm trying to apply seperate equations for different land types. I have created a raster containing only the land type I'm interested in. I then reclassed the values to '0'. My plan was to use the raster calculator with the equation and add + "reclassed raster", which would be +0, thus only returning values that are within the area I'm interested in. However, when I try the calculation, it doesn't work properly, giving me something like values from -3e20 to +3e20 but there are no values or points actually there. If I do the raster calculator without the "+ reclassed raster", it works perfectly, so the equation itself (or other data layers) is not the problem. If I look at the reclassed raster, there is no attribute table, and every time I try to build one it fails. Any ideas on what's going wrong or a better way to do this? Thanks!!!
Yes, it's ArcGIS 10.1 with Spatial Analyst. The reclassify doesn't give me an empty raster (only no attribute table), it's only when I use the raster calculator.
Best Answer
If you provide more detail on how you reclassified and the specific raster calculation used to get the empty data raster (usually indicated by -3e20 to +3e20) that will be helpful in troubleshooting the problem.
Assuming ArcGIS with Spatial Analyst, if reclassify and raster calculator are giving you empty output then try the following two tools to achieve the result you need:
Set Null can be used to set all other values not equal to the one you're interested in as NoData - a much more straightforward method than reclass to change values to NoData.
Extract by Mask can then be used to isolate cells within the other raster wherever there are values in the set null output. And then you can use this masked raster when calculating the corresponding equation (or more efficiently use the SetNull output as a mask in the environments and calculate on the original land raster).
Perhaps a more simplified approach will be to use the Con tool to apply your separate equations inside conditional statements for different land types. Basically, they may look something like this (substitute with your file names):