topic Re: Create Random Points in Geoprocessing Questions

Create Random Points

BenjaminRichards — Wed, 13 Jun 2018 20:16:45 GMT

I am trying to create 3 random points with a minimum separation of 75 meters within each polygon of the attached shape file. I am using Sampling -> Create Random Points

The tool runs to completion with no error messages. However, upon inspection, many of the polygons contain 2 points, not 3.

Any thoughts?

Re: Create Random Points

DanPatterson_Retired — Wed, 13 Jun 2018 20:49:37 GMT

Basically those types of algorithms will fit as many as they can within the number of tries it is given and will get as close as it can given the spatial area that it has to work with.

In short... it may try 100 combinations to fit 3 in... each time it fails only producing 1 or 2... then it gives up

Your options...

modify the code (not possible with esri scripts).
reduce the inter-point spacing (may not be as mission-critical at all)
make the area bigger (probably not)

I have written a similar toolset that does the same thing,

Point Tools for Pro … # 7

but I likewise tried to get as close as possible to the target number within what I considered a reasonable period of time. Beyond that... the user can plunk in a point themselves if they can find a fit.

Re: Create Random Points

BenjaminRichards — Wed, 13 Jun 2018 20:58:56 GMT

Thanks Dan. The weird thing is that it doesn't throw an error. If I increase the inter-point spacing from 75m to 100m, it then throws an error. 3rd party tools such as ETGeowizards don't seem to have any trouble placing 3 random points per grid with the 75m inter-point spacing.

Re: Create Random Points

DanPatterson_Retired — Wed, 13 Jun 2018 21:00:41 GMT

100 means that it didn't work

Maybe Ianko's toolbox tries harder to get the job done