AnsweredAssumed Answered

Tabulate Intersection inconsistent

Question asked by griner on Dec 19, 2017
Latest reply on Dec 19, 2017 by Dan_Patterson

Tabulate intersection for different geometries produces inconsistent outputs.

I have class features in layers of point, line and polygon geometries.  I'm using TabulateIntersection_analysis to to determine the portion of each class feature that is in a county (using a polygon layer of county boundaries).  So, the Zone layer has to be the county boundaries layer, and each analysis uses a different tabulating class layer (point, line, poly) across those counties.

For points, the output makes sense, the results contain 2 columns: "PNT_COUNT" and "PERCENTAGE". For these points, the value in PERCENTAGE contains the percentage of the class' points that are in that county.  For a given Class Field value, the total percentages add up to 100%, and the number of points add up to the total number of points for the given class Field value.

Likewise, for lines, the result contains "LENGTH" and "PERCENTAGE" and the Percentage values for a given class field value add up to 100%.

BUT.. when the class layer is a polygon, the outputs are "AREA" and "PERCENTAGE" but the values for PERCENTAGE represent percent of Zone, not percent of that class field value in that county. This is, effectively, the opposite of the results for the line and point geometry class layer outputs.

I realize that by swapping Zone and Class parameters for polygon-only features, I get what I want, but I now have to write code to detect the class feature's geometry type and call tabulateIntersection_analysis with differently arranged parameters depending on the class feature's geometry.

 

Surely, something isn't working the way it's intended!?!?

 

Context:

ArcGIS Desktop 10.4.1

Python (arcpy)

Windows 7

Outcomes