CODEWITHSUNDEEP
postgresqlgispostgisgeodjango
user1333095
user1333095

Reputation: 53

creating a polygon from points around a point in postgis

I have a postgresql db using postgis 2.0 and a table of thousands of points, I would like create a polygon of the furthest points originating around a particular central location. I haven't got a clue how this would be done, any ideas anyone??

Upvotes: 1

Views: 1257

Answers (1)

Mike T
Mike T

Reputation: 43622

Filter and aggregate the points, and return the convex hull of the points.

So to select the points in mytable that are within a distance of 10 from id=123, and return the enclosing polygon:

SELECT ST_ConvexHull(ST_Collect(A.geom))
FROM mytable A, mytable B
WHERE B.id=123 AND ST_DWithin(A.geom, B.geom, 10)

Upvotes: 2

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