This might help http://trac.osgeo.org/postgis/wiki/UsersWikiplpgsqlfunctions
upgis_lineshift(centerline geometry, dist double precision) Though its simplified in the sense it bases on start and end points of the linestring to do the shift. To do true shifting when you have very curvy lines or polygons - you'd probably want to use Simon's approach. http://www.spatialdbadvisor.com/postgis_tips_tricks/128/exploding-a-line string-or-polygon-into-individual-vectors-in-postgis/ (hmm I though he had that wrapped more nicely in a function, but can't find it). Hope that helps, Regina -----Original Message----- From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-boun...@postgis.refractions.net] On Behalf Of Andreas Neumann Sent: Tuesday, June 16, 2009 7:53 AM To: PostGIS Users Discussion Subject: {SPAM: 40} :[postgis-users] Open buffers or parallel lines Hi all, I am looking for either a "parallel line" feature or "open buffers around a linestring element". The idea is to visualize a waste-water system where in large map scales the actual diameter of the waste-water pipes (canalization). The linecaps shouldn't be stroked, but the parallel offset to the centerline should be drawn. Are there any tricks how this can be done in Postgis? I see that there is st_buffer, but there is no option to get an open buffer or parallel lines. Thanks for any hints, Andreas -- Andreas Neumann http://www.carto.net/neumann/ http://www.svgopen.org/ _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users ----------------------------------------- The substance of this message, including any attachments, may be confidential, legally privileged and/or exempt from disclosure pursuant to Massachusetts law. It is intended solely for the addressee. If you received this in error, please contact the sender and delete the material from any computer. _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
