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2 NOTE Most of the overlay analysis types work only with polygon topologies.
For more information about those that work with node or network topologies,
see the Concept tab for this topic (page 1336).
3 In the
Topology Overlay Analysis - Analysis Type dialog box (page 1999),
do the following:
■ Select the type of overlay analysis to perform:
■ Intersect — Only areas that appear in both the source and overlay
topologies are in the result topology.
■ Union — Areas that appear in either the source or the overlay
topologies are in the result topology.
■ Identity — The result topology includes areas that appear in the
source topology and areas in the overlay topology that are within
the source topology boundary.
■ Erase — The result topology includes areas that appear in the source
topology except where it is covered by the overlay topology. The
area covered by the overlay polygons is erased from the source
polygon area.
■ Clip — The result topology includes areas that appear in the source
topology except where they are outside the boundary of the overlay
topology. The source polygons are clipped to the outer boundary
of the overlay polygons.
■ Paste — The overlay topology is "pasted" on the source topology.
The result topology includes the overlay topology and any areas
of the source topology that extend beyond the boundaries of the
overlay topology.
■ Click Next.
4 In the Select Overlay Topology dialog box, do the following:
■ Select the polygon topology to use as the overlay topology.
■ Click Next.
5 In the Topology Overlay Analysis - New Topology dialog box, do the
following:
■ Select Highlight to highlight the resulting topology onscreen. Select
the highlight color.
1340 | Chapter 8 Analyzing Data