Franklin's Point Inclusion in Polygon (PNPOLY) Algorithm

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This Demonstration implements Franklin's point inclusion in polygon (PNPOLY) algorithm [1] that tests whether a point is inside a polygon (convex or concave). The idea, based on Jordan's curve theorem, is to count how many times a ray from the test point crosses an edge of the polygon. At each crossing, the status changes from inside to outside or vice versa.

Contributed by: Frederick Wu (October 2018)
Open content licensed under CC BY-NC-SA



[1] W. R. Franklin. "PNPOLY - Point Inclusion in Polygon Test." (Oct 9, 2018)


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