Polygon Clipping
A polygon is a contained area on the system map that is defined by the user. Polygons and polygon boundaries help develop service routes as well as determine client mobility within the service area. These are defined in Trapeze PASS.
After the buffer around a selected area is generated, the polygons within it are processed. Some polygons are clipped to the buffer, that is, only partially within the buffer.
Clipping polygons modifies the polygon to fit inside the buffer and determines the percentage
of area removed from the polygon to make it fit. Any data that is associated with the polygon
is adjusted to reflect that percentage. The following table shows an example of polygon
clipping results.
| Area | Results |
|---|---|
|
Original Polygon Area |
1 square mile |
| Clipped Polygon Area | .5 square mile |
| Original Data Value | 5000 persons |
| Calculated Data Value | (Clipped Polygon Area / Original Polygon Area)*Original Data Value = 2500 |