"Create random points" tool creating too many points in Pro

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06-07-2019 01:53 AM
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New Contributor III

Hi, I'm having a bit of a problem as I'm trying to generate a random sample of points in ArcGIS Pro 2.3.2., and it keeps returning far too many!

You can see in the screenshot that my inputs are requesting 40,000 points and it's returning 812444. The warning was "WARNING 000983: The specified number of points could not be created in all cases due to restrictions from the minimum allowed distance." There's definitely enough room for them in this area as when i generated a point per 5m raster cell in this area there were 4 million points!

Am I doing something wrong here or is this a bug? Thanks.

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New Contributor III

Partially answering my own question here. I made one mistake, which was to mistakenly use a line file as the input, thinking it was just taking the extents, when in fact it was only only generating along the lines. However, it still doesn't explain why it tried to create too many points! Doing it on a polygon worked perfectly and returned the expected number.

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MVP Esteemed Contributor

Helen

Create Random Points—Data Management toolbox | ArcGIS Desktop (from ArcGIS Pro)

Did you specify the contraining extent or featureclass as well?

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New Contributor III

Apologies, when I said a line file as input, I meant as the constraining features, so the points just generated along the lines. You can see in the attached image above it's the fishnet line file I used by accident. Using the polygon worked perfectly, but just still perplexed as to why it would make more points than requested!

Thanks.

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MVP Esteemed Contributor

What were the 'warnings' at the bottom of the dialog?

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New Contributor III

Hi Dan - it's in my original post!

 

Cheers 

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New Contributor III

This has just happened again, this time with one of my student's work. Her problem was something to do with her underlying polygon. Creating a brand new one to constrain the features meant the correct number of points was returned, rather than three or four times the specified amount!

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New Contributor

Hi,

I had the same issue. In my case, my selected "Constraining Feature" had multiple sections I were not aware of, hence the specified amount of points were created for each separate part of the constraining feature.

Hope this helps someone!

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New Contributor

Thanks Beenard! You are right! 

For other people who want to generate random points along with lines, you need to dissolve your line layer into one single feature and then set the total number and minimum allowed distance for random points. Otherwise, the number of points will be applied to every single features in your line layer. 

Hope this helps!

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