topic Re: Finding minimum distance between a set of coordinates in SAS Studio

Finding minimum distance between a set of coordinates

Sanchit — Sat, 30 Jul 2016 20:54:03 GMT

Hi,

I have a dataset like this:

Lat	Long
51.39824	-0.09366
51.52927	-0.04583
51.54182	0.038004
51.41895	-0.30561
51.59302	-0.06998
51.60087	-0.19474
51.55101	-0.13727
51.50019	-0.07006
51.48329	-0.02586

I need to determine the minimum distance between these set of coordinates. I know about a function geodist() to determine distance between 2 coordinates, but not sure how to loop over through this set from the table.

Greatly appreciate your help.

Thanks!

Re: Finding minimum distance between a set of coordinates

LinusH — Sat, 30 Jul 2016 21:52:57 GMT

Try the min() aggregate function in SQL, or PROC SUMMARY using the outcome oD geodist() as input.

Re: Finding minimum distance between a set of coordinates

Reeza — Sat, 30 Jul 2016 21:54:24 GMT

You have to check distance between all unfortunately.

Use a Cartesian join in SQL and the GEODIST() function.

Heres a sketch of the code.

Proc SQL;

Create table dist as

Select a.*,
            B.lat as lat2,
            B.long as long2,
            Geodist(....) as distance
From have as a
CROSS JOIN 
have as b
Order by distance;
Quit;

Re: Finding minimum distance between a set of coordinates

Sanchit — Sun, 31 Jul 2016 21:48:43 GMT

Thanks a lot Reeza. It worked!

🙂

-Sanchit