Alteryx Designer Knowledge Base

Definitive answers from Designer experts.

How to Emulate a Concave Hull

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In its spatial tools, Alteryx includes an option to create a convex hull polygon from a series of points. However, depending on the type of analysis requested, it can be more ideal to create a concave hull instead. An example of this would be the need to group customer points into trade areas thematically based on store location. If the standard method of convex hull polygon creation were used, it would be possible to create polygons that overlap, which would not be the desired outcome. A demostration of this is shown below. Module attached.

Example:



To avoid this, one can first project non-overlapping trade areas from the points and spatially combine them to eliminate the overlap.


To then remove the excess area projected, the object can be trimmed to the original convex hull boundaries.


To further process and remove the resulting holes, spatial generalization can then be used.

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