See ST_buffer at http://postgis.refractions.net/docs/ch06.html#id2594743
Buffer generates a buffer zone around an existing geometry a specified distance out (or in if -ve) using a specified number of points. A buffer around a point is a circle if you use enough points, if you could buffer a point with 4 points, you'd get a square centred on the point instead of a circle. Cheers Brent Wood --- On Sat, 6/14/08, Bob Pawley <[EMAIL PROTECTED]> wrote: > From: Bob Pawley <[EMAIL PROTECTED]> > Subject: Re: [postgis-users] Circle > To: "PostGIS Users Discussion" <postgis-users@postgis.refractions.net> > Date: Saturday, June 14, 2008, 11:54 AM > Is that the only function of the buffer - to create a > circle? > > Can the buffer modify other functions. If so - what is the > criteria? > > Bob > ----- Original Message ----- > From: "Paul Ramsey" > <[EMAIL PROTECTED]> > To: "PostGIS Users Discussion" > <postgis-users@postgis.refractions.net> > Sent: Friday, June 13, 2008 4:33 PM > Subject: Re: [postgis-users] Circle > > > > Try it and see :) > > It constructs a circular-shaped polygon around the > point. > > P > > > > On Fri, Jun 13, 2008 at 4:23 PM, Bob Pawley > <[EMAIL PROTECTED]> wrote: > >> I'm interested in what the buffer actually > does. > >> > >> Bob > >> > >> ----- Original Message ----- From: "Paul > Ramsey" > >> <[EMAIL PROTECTED]> > >> To: "PostGIS Users Discussion" > <postgis-users@postgis.refractions.net> > >> Sent: Friday, June 13, 2008 3:46 PM > >> Subject: Re: [postgis-users] Circle > >> > >> > >>> ST_Buffer(ST_MakePoint(x,y),r) > >>> > >>> On Fri, Jun 13, 2008 at 3:35 PM, Bob Pawley > <[EMAIL PROTECTED]> wrote: > >>>> > >>>> What is the best way of creating a circle? > >>>> > >>>> Mu PostgreSQL Developes Handbook susy it > should be - point and radius. > >>>> > >>>> Postgis doesn't seem to have this > function. > >>>> > >>>> Bob > >>>> > _______________________________________________ > >>>> postgis-users mailing list > >>>> postgis-users@postgis.refractions.net > >>>> > http://postgis.refractions.net/mailman/listinfo/postgis-users > >>>> > >>> > _______________________________________________ > >>> postgis-users mailing list > >>> postgis-users@postgis.refractions.net > >>> > http://postgis.refractions.net/mailman/listinfo/postgis-users > >> > >> _______________________________________________ > >> postgis-users mailing list > >> postgis-users@postgis.refractions.net > >> > http://postgis.refractions.net/mailman/listinfo/postgis-users > >> > > _______________________________________________ > > postgis-users mailing list > > postgis-users@postgis.refractions.net > > > http://postgis.refractions.net/mailman/listinfo/postgis-users > > > _______________________________________________ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
