Table of Contents
...
This process generates a lines shapefile with one line ('arc') along each border between nodes, and identifies the left and right polygon Feature Identifiers (FIDs) for each line feature. By convention, the outer polygon boundary is always stored in a clockwise direction so while every line will have a polygon on its right; lines on the exterior of the input shapefile will have no polygon on their left. The attribute table indicates these cases with the LEFT_FID = -1.
The remaining processes are completed in ArcGIS Desktop or Pro, regardless of the software environment used above. (Illustrations are for ArcGIS Pro.)
...
Do not expect all records to match - because the ‘left’ side of all exterior lines will have no neighbouring polygon. Do not worry if you receive a “Field names that match reserved words should not be used in database schema and can cause the join to fail. The following fields match reserved words….” message. Close the 'Join Validation' dialogue box after inspecting the result.
’Click 'OK'
- Open the output polyline shapefile attribute table
- Use the Field Calculator to calculate all the LEFT_An values (for the LEFT_An files recently added to the polyline shapefile) equal to the corresponding administrative levels of the polygon shapefile. (ArcGIS may require you to begin an edit session.)
...
- Close the attribute table, remove the join, and establish a new join basing on 'RIGHT_FID'. Anticipate all the lines layer feature records matching. (This is because, unlike the join based on 'LEFT_FID', every feature has a polygon on its right side.)
- Open the output polyline shapefile attribute table.
- Use the Field Calculator to calculate all the RIGHT_An values (for the RIGHT_An files recently added to the polyline shapefile ) equal to the corresponding administrative levels of the polygon shapefile.
- Remove the join.
...