Introducing Geographic Information Systems with ArcGIS: A Workbook Approach to Learning GIS, 3rd Edition

The Raster Calculator—Integer Rasters

____ 12. Use Search to find the tool Raster Calculator (Spatial Analyst). Write here the path to it. You will be using it a lot.

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(Now would also be a good time to make sure the Spatial Analyst extension is turned on: Customize > Extensions > Spatial Analyst.) The Raster Calculator lets us do fundamental operations on rasters. To use it, you put a Map Algebra expression into the calculation box. This expression can be very involved, but in the next step you will place only the name of the raster you have been working with, with the goal of creating a duplicate of that raster with a different name.

____ 13. Start the Raster Calculator. (You may have to expand the window or make it full screen so you can see it all.) Make a second raster that is identical to the first simply by double-clicking Basic_Raster so that it is placed in Map Algebra expression box. Browse and put the output in Ras_Expr.gdb, calling it Bas_Ras2. Click OK and, shortly, Bas_Ras2 will be added to the map when the Raster Calculator is finished. Verify that it is identical to Basic_Raster (despite the fact that different colors are used for the cell values).