Knowledge Base - Technical Articles
HowTo: Reverse the direction of a polyline using the Field Calculator
|Software:||ArcView GIS 3.0, 3.0a, 3.0b, 3.1, 3.2, 3.2a|
The direction of a polyline is established when it is first digitized, from start point to end point. You can determine the direction of a polyline by symbolizing the theme with the arrow line symbol from the Default.avp ArcView Palette. You can reverse the direction of some, or all polylines in a shapefile, using the Flip request in the Field Calculator.
- Select the set of polyline features whose direction you want to reverse. If you want all the polylines in the shapefile, do not select any records.
- Open the polyline theme attribute table.
- Click Start Editing from the Table menu.
- Select the Shape field in the Attribute table.
- Click Calculate from the Field menu.
- Double-click the [Shape] field from the list of fields. It will appear in the expression box.
- Type .Flip after [Shape]. The expression should look like this:
- Click OK.
- Click Stop Editing from the Table menu.
Last Modified: 1/11/2002
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