## Convex hull algorithm in SAS/STAT or SAS/BASE

Super Contributor
Posts: 261

# Convex hull algorithm in SAS/STAT or SAS/BASE

I don't have SAS/IML license so I was wondering if there is an algorithm that can be used in SAS/STAT or Base? I don't mind if it's not that efficient or is a bit messy. I want to calculate the convex hull of lots of 8 point polygons simulated as follows:

data obs;

do i= 1 to 8;

x= round(1000* ranuni(123),1);

y= round(1000* ranuni(789),1);

output;

end;

run;

Super User
Posts: 8,634

## Re: Convex hull algorithm in SAS/STAT or SAS/BASE

Here is a link some algorithms, and there is liknk to Qhull there which may also help.

mg.metric geometry - Algorithm for finding the volume of a convex polytope - MathOverflow

Super Contributor
Posts: 261

## Re: Convex hull algorithm in SAS/STAT or SAS/BASE

Hi RW9

I'm interested in getting the convex hull of a two dimensional polygon - the volume of a polytope is not what I'm looking for.

If you download the student university edition of SAS do you get SAS/IML? I know you can do it fairly easily there.

Thanks

Super User
Posts: 8,634

## Re: Convex hull algorithm in SAS/STAT or SAS/BASE

Super Contributor
Posts: 261

## Re: Convex hull algorithm in SAS/STAT or SAS/BASE

Do you know if you can use the CVEXHULL Function in the university edition? there in an * next it so I'm not sure if this is included.

Super User
Posts: 8,634

## Re: Convex hull algorithm in SAS/STAT or SAS/BASE

Afraid I have not used UE.  Perhaps consider posting request for information in the SAS UE domain, or the IML domain as this isn't really graph related.

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