Spatial Analysis Based on Raster Data Processing - Introducing Geographic Information Systems with ArcGIS - page 520

FIGURE 8-51
30. Open Proximity_startup.mxd. Add TryThis as a source raster and Tolls as a cost raster. Make the
color ramp of Tolls “Purple Bright” treating its T/C labeling as you when you added it last time.
31. Find and start the Cost Allocation tool. TryThis is the Input raster. Value should be in the Source
field. Tolls is the Input cost raster. Browse to Prox_Exp.gdb and name the Output allocation
raster CostAllo. Make the Maximum distance 30. Call Output Distance raster CostDist. Call
the Output backlink raster CostDir. Double-check that you are using Prox_Exp.gdb for all output
rasters. Click OK.
32. The new rasters should appear in the T/C. Collapse the legends in the T/C. Click on List By Drawing
Order, and arrange the entries in the T/C in the following order: Square_Grid, TryThis, CostAllo,
CostDir, CostDist, Tolls. Turn off all except Square_Grid and TryThis. Examine TryThis with Identify,
and the T/C (which you may have to re-expand), so you know what is where.
33. Start the Identify tool and set it so that it shows the values of CostDist, even though that
layer is turned off. Position the cursor in the cell whose center is at location approximately
(85, 15). The cost (Pixel value) from that cell should be about 21. Examine other cells in the
accumulated cost raster. What is the cost from (5, 55)? ________.
34. In the T/C, turn on and expand the allocation raster CostAllo. Examine CostAllo with Identify.
Verify that the cell at (85, 15) is allocated to (generates the least-cost path to) a source cell