Creating Spatial Feature Classes Based on Proximity, Overlay, and Attributes - Introducing Geographic Information Systems with ArcGIS - page 420

Toolboxs > ___________________________________. Click on the path text. Toolboxes will open.
Besides Union, what other tools do you find under Overlay?
________, ________, ________, ________, ________, ________.
Start the Union tool by double-clicking the hammer icon. Read the Help panel for Union. Click
the Input Features text box. Read the Help for that. For the first Input Feature class you can
either click the down arrow at the end of the Input Features text box and choose Two_Stalks, or
you can browse to
___IGIS-Arc_ YourInitials \Trivial_GIS_Datasets\Overlay_Exercise.mdb\Trivial_Feature_Classes\
TwoStalks
Add Two_Stalks. Specify a second input as the ThreeBars feature class from Trivial_Feature_
Classes. Put the output feature class in Trivial_Feature_Classes (being careful about the path—
you will have to use the yellow “browse” icon), calling it Stalks_Bars_mpp. For Gaps Allowed
make sure the box not checked. (By not allowing gaps you instruct the software to create
polygons in areas completely surrounded by the polygons of the union; the polygons formed,
where there would otherwise be gaps, are not, in fact, part of the union.) Click OK and watch
the messages go by. Close the Union window. When the resulting map appears spend some
time with the Identify tool looking at the resulting polygons and their attributes.
The Union tool, by default, creates multipart polygons (hence we added “mpp”). That is, all the
polygons that have the same values for the attributes (like LOCATION and PLACEMENT) become
a single, multipart polygon. Sometimes this is useful and sometimes not. You can make the
multipart polygons into singlepart polygons easily. You exploded multipart features before with
the Advanced Editing toolbar of the Editor, but let's look for a different way.
7. Type Explode into the search box. Explode doesn't come up directly, but you see Multipart to
Singlepart (Data Management), which is what you want. If you click on the middle of the three
lines, you find a Description of the tool. In that Description are tags, one of which is explode,
which is how Search found the tool. In the ArcCatalog window collapse everything related to
Toolboxes. Click the third line of the Multipart to Singlepart tool item to bring up ArcCatalog with
the Toolboxes expanded to show the Multipart to Singlepart tool. What is the path to the tool?
Toolboxes > ____________________________________________
Make sure no features are selected. Run the tool on Stalks_Bars_mpp to make Stalks_Bars_
spp (for single-part polygons). Make sure it goes into Trivial_Feature_Classes.
8. When the computation is finished hide ArcCatalog, if that is where the tool came from. In
the ArcMap T/C turn off all other layers. Stalks_Bars_spp was probably added to the map
automatically. If not, add it. Make the layer color light green.
9. In the Layer Properties window for Stalks_Bars_spp, click Labels. Check Label features in this
layer. Click Expression in the Text String pane. Place the following expression in the box:
[LOCATION] & vbNewLine & [PLACEMENT]
Click OK. Change the font size to 7. Click Apply. Click OK.