How to obtain a proportional spatial sum using multiple clippers in FME?

Question

I'm creating a workspace to automate a proportional spatial sum.

I have polygons with employment data.

And I have bus stops that I'm using to create multiple buffers as my zones of interest.

I'm testing this with zones I've already caculated with MapInfo GIS software so I know what values I'm suppose to have in the end, and i'm able to compare this with FME workspace results.

But I also need those stats for each bus separately. To do so, instead of aggregating indifferently all points, I do it with a group by using my bus name attribute.

If I add a tester before the buffer, in order to filter only one bus, I have the exact result.

As soon as there is more than one zone of interest the results are false.

My guess is that I don't know how to use the clipper correcly with multiple zones as clippers (even if the clipper type is on "multiple clippers").

Any ideas or other method to accomplish this ?

Answer 1

The total input area of the clippees usually matches the total output of the clipped area.

Meaning that none of the output clipped areas should overlap.

If some of the clippers overlap you might get unexpected results.

At least this has been my experience.

The AreaOnAreaOverlayer might give you better results