Hi FME Experts,
I have a feature class, and I received a new copy of this feature, I have used the "update detector" transformer to detects the changes between the two sets of input features.
for the updated data (geometry), I need to find a way to compute the percentage of the changing in the data.
I have tested the new release of the "ChangeDetector" transformer, but it does not give a percentage. of the change.
Please advise me about this matter.
Thank you in advance.
Assuming your data is polygons and the ID does not change, this could be the workflow:
Calculate the area of the original polygon (AreaCalculator): area_orig
Use an AreaonAreaOverlayer (group by ID) and Tester (_overlaps > 1) to find the overlapping parts.
Use a Aggregator (group by ID) on the overlapping parts.
On the overlapping part, repeat the AreaCalculator to get area_new.
Your change will be: (area_orig - area_new) / area_orig
This can be calculated using the ExpressionEvaluator
Hope this helps.