Geography Reference
In-Depth Information
your personal folder. Click it. Click Open. Windows may ask if you want to allow the program to
make changes to your computer. Say Yes. Windows may ask again. Say Yes again. An Added
Objects window with six listed objects will appear. OK this window. Shortly, CellTool will appear,
highlighted, among the toolbars. Close the Customize window.
From this point on, CellTool will be available just as any other toolbar through Customize >
Toolbars.
1
Add the CellTool toolbar. Looking at ToolTips (or the Status bar), record in the spaces
provided the functions of the five icons on the Cell Tool toolbar. See Figure 8-37.
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FIGURE 8-37
11.
If you click the Value icon and then an interior cell, you will see the values of that cell and the
eight around it. (If you get an error, just OK it and try again.) If you drag a box that includes a
number of cells, you will see the values of all of them. Experiment. Click the Clear Graphics
icon. Experiment some more. Clear Graphics.
Important note:
The Cell tool works only on the raster at the top of the T/C. Should you fail to
clear graphics, and then create a new raster, the graphics from the previous raster will remain—
showing wrong results for the new raster.
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
1
CellTool can be a bit cantankerous. You may have to quit ArcMap. Restart it, add the CellTool toolbar, then add
Basic Raster. Even so, the first time you click on a cell, looking for Value, you may get an “Error in CellValueExtent”
message. Just click some more.
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