How do i get a bounding polygon around points?

Question

I have a table with thousands of addresses as points.

Is there a function in postgis that will allow me to get a bounding polygon around these points and return it as a polygon?

update I am looking for a more complex polygon than just a bounding rectangle

score 18 · Accepted Answer · edited Jun 16 '15 at 13:42

18

It may be not 100% clear from your question what you mean as more bounding polygon. It may be understood as

minimum bounding rectangle (also known as MBR or envelope) for which you can use ST_Envelope, ST_Box2D or ST_Extent,
as s a minimum geometry which encloses all points within given geometry, a convex envelope and in this case you can use ST_ConvexHull or even ST_ExteriorRing if your input would be a polygon,
As Pimin pointed in the comments below, ST_ConcaveHull is another option worth to consider, available since PostGIS 2.0.0.

edited Jun 16 '15 at 13:42

Jonáš Veselka

answered Feb 03 '10 at 01:34

mloskot

2

There is also ST_ConcaveHull in the most recent PostGIS, if you want a smaller polygon.. – Pimin Konstantin Kefaloukos May 13 '13 at 11:20

score 4 · Answer 2 · edited Jul 13 '22 at 20:15

4

ST_Extent provides an aggregate function that returns a bounding box that bounds a set of geometries.

edited Jul 13 '22 at 20:15

Kevin Sylvestre

answered Jan 14 '10 at 10:53

Andrew McGregor

1

thanks. is there a way to get a more complex polygon than just a bounding box? – ADAM Jan 24 '10 at 10:30

2 Answers2