Rasters can be produced that indicate “truth values” or Boolean3
values, in cells. A “1” stands for TRUE. A “0” stands for FALSE. Suppose you were interested in knowing which cells in Basic_Raster were greater than or equal to 25.
____ 17. Calculate Basic_Raster >= 25. “Basic_Raster >= 25” is a statement that is either true or false, correct? The result, name it True_or_False, will have a 1 (for TRUE) in those cells that were 25 or more. A zero will appear in the other cells, as you can see from the T/C, the Identify tool, and the attribute table. (The CellTool may indicate ND for NoData; ignore it.)
The Boolean operators may be used in general expressions as well. Zero values are assumed to be FALSE. Nonzero values are considered TRUE.