[postgis-users] Intersecting lines to Polygons

[chlists]

Stephen & Nicolas,

many thanks for your pointers. Based on your suggestions I have found this blog post of Simon Greener which describes pretty much exactly what I'd like to do:

http://www.spatialdbadvisor.com/postgis_tips_tricks/120/building-polygons-from-overlapping-linestrings-requiring-intersection


Cheers,
Chris



On 12/03/2013, at 12:59 AM, Stephen V. Mather wrote:

> Depending on how your lines are constructed, you might also look to ST_Union or ST_Node to create the nodes for overlapping lines, which you will likely need, then feed that into ST_Polygonize or ST_BuildArea.
> 
> Best,
> Steve
> 
> Stephen V. Mather
> GIS Manager
> (216) 635-3243 (Work) 
> clevelandmetroparks.com
> 
> 
> 
> 
> 
> From: postgis-users-bounces at lists.osgeo.org [postgis-users-bounces at lists.osgeo.org] on behalf of Nicolas Ribot [nicolas.ribot at gmail.com]
> Sent: Monday, March 11, 2013 9:29 AM
> To: PostGIS Users Discussion
> Cc: PostGIS Users Discussion
> Subject: Re: [postgis-users] Intersecting lines to Polygons
> 
> Hi,
> 
> Look at st_polygonize() and st_buildArea()
> 
> Topology can also be of a great help here.
> 
> Nicolas
> 
> 
> On 11 March 2013 13:13, chlists <chlists at me.com> wrote:
> Hi list,
> 
> I'd like to combine a global compilation of line data which intersect into a global polygon dataset. ArcGIS has a tool called 'Features to Polygons' which does this in one step for which I have yet to find an equivalent in PostGIS. ST_MakePolygon and ST_Polygon require closed linestrings. I have simple line features which randomly connect like in the attached screenshot. There are no attributes which describe which polygon a single linestring belongs to. Can this be done easily or does this involve building topologies? Any pointers much appreciated.
> 
> Thanks,
> Chris
> 
> 
> 
> 
> 
> _______________________________________________
> postgis-users mailing list
> postgis-users at lists.osgeo.org
> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
> 
> 
> _______________________________________________
> postgis-users mailing list
> postgis-users at lists.osgeo.org
> http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users