Re: [postgis-users] Topology: cannot delete slivers (or gaps)
Just FYI in case you’re interested I found it much easier to use the triangle algorithm here https://github.com/tudelft3d/pprepair on an exported shape file It’s called Planar Partition Repair. It got rid of all the slivers and overlaps with ease. Here is the paper http://www.gdmc.nl/ken/files/12_pfg.pdf and thanks to Martijn Meijers and team. Then I rebuilt the topology layer in PostGIS from the fixed up Simple Feature Class multi polygon layer. -- John Abraham j...@hbaspecto.com 403-232-1060 On Nov 3, 2014, at 9:13 AM, Rémi Cura wrote: > Just for completeness sake, > if your input geom is really ambiguous with the precision you choose, > it may be faster in both human and machine time to use grass 7 to import and > clean the topology, > then export from grass 7 to postgis topology with the built-in grass function. > > I ressort sometime to this trick because grass cleaning functionality are > very advanced. > > Cheers, > Rémi-C > > > 2014-11-03 17:04 GMT+01:00 Guillaume Drolet : > Sandro Santilli wrote > >> I suggest you take a look at edges having face 1831 on either > >> the right or left edge. Do any edge exist ? > > > > edge 5187 has face 1831 as its right face > > > >> The correct procedure to drop those slivers would be to assign > >> those small areas to the (closest|biggest|leftmost|youpickit) > >> TopoGeometry object, to one and only one, and then, if you really > >> need it, drop the edge internal to the TopoGeometry. > > > >> I made a QGIS plugin which may help you do some of these things > >> manually, which is useful in some cases, mainly to understand the > >> issues. > > > > The plugin you made is a great tool (thanks). I will first try to get the > > number of slivers down to > > a manageable number, which I had with setting the tolerance at 2.0 m, and > > then apply the > > TopoGeometry approach above. > > > >> So the error was right about there being another edge attached to the > >> node: > > > >> ERROR: SQL/MM Spatial exception - other edges connected (3912) > > > >> I'm guessing 3912 and 3908 are the two parallel edges in the picture > >> you attached: https://dl.dropboxusercontent.com/u/5196336/example1.bmp > > > > You're right, they are the two parallel edges. And it's the same for most > > of > > the some 650 slivers I have. > > > >> Again, QGIS may help you getting more info out of the visual, enable > >> the DBManager core plugin, select your topology schema and select > >> Schema->TopoViewer from the menu. > > > > I didn't know about the TopoViewer tool. I was importing the topology > > tables (node, edge, face) > > like any other PG geometry tables. Will explore with this new tool. > > > > > >> It's probably easier to clean up nodes for an areal topology than to > >> clean up faces. With my QGIS plugin (PostGIS Topology Editor) you can > >> select all nodes and click on a button which will drop all the ones > >> that are safe to drop. > > > > You're right! I'll create my topology again but with the 2.0 m tolerance, > > then run > > my function for getting rid of nodes that are not at intersections and > > finally, > > I will use the approach you suggested of working with the TopoGeometry > > objects and the > > relation table to eliminate the remaining slivers. > > > > Will keep you posted on how it goes. Again, I really appreciate your help. > > Thanks. > > > > Guillaume. > > > > > > -- > View this message in context: > http://postgis.17.x6.nabble.com/Topology-cannot-delete-slivers-or-gaps-tp5007250p5007266.html > Sent from the PostGIS - User mailing list archive at Nabble.com. > ___ > postgis-users mailing list > postgis-users@lists.osgeo.org > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users > > ___ > postgis-users mailing list > postgis-users@lists.osgeo.org > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users ___ postgis-users mailing list postgis-users@lists.osgeo.org http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
Re: [postgis-users] Topology: cannot delete slivers (or gaps)
Just for completeness sake, if your input geom is really ambiguous with the precision you choose, it may be faster in both human and machine time to use grass 7 to import and clean the topology, then export from grass 7 to postgis topology with the built-in grass function. I ressort sometime to this trick because grass cleaning functionality are very advanced. Cheers, Rémi-C 2014-11-03 17:04 GMT+01:00 Guillaume Drolet : > Sandro Santilli wrote > >> I suggest you take a look at edges having face 1831 on either > >> the right or left edge. Do any edge exist ? > > > > edge 5187 has face 1831 as its right face > > > >> The correct procedure to drop those slivers would be to assign > >> those small areas to the (closest|biggest|leftmost|youpickit) > >> TopoGeometry object, to one and only one, and then, if you really > >> need it, drop the edge internal to the TopoGeometry. > > > >> I made a QGIS plugin which may help you do some of these things > >> manually, which is useful in some cases, mainly to understand the > >> issues. > > > > The plugin you made is a great tool (thanks). I will first try to get the > > number of slivers down to > > a manageable number, which I had with setting the tolerance at 2.0 m, and > > then apply the > > TopoGeometry approach above. > > > >> So the error was right about there being another edge attached to the > >> node: > > > >> ERROR: SQL/MM Spatial exception - other edges connected (3912) > > > >> I'm guessing 3912 and 3908 are the two parallel edges in the picture > >> you attached: https://dl.dropboxusercontent.com/u/5196336/example1.bmp > > > > You're right, they are the two parallel edges. And it's the same for most > > of > > the some 650 slivers I have. > > > >> Again, QGIS may help you getting more info out of the visual, enable > >> the DBManager core plugin, select your topology schema and select > >> Schema->TopoViewer from the menu. > > > > I didn't know about the TopoViewer tool. I was importing the topology > > tables (node, edge, face) > > like any other PG geometry tables. Will explore with this new tool. > > > > > >> It's probably easier to clean up nodes for an areal topology than to > >> clean up faces. With my QGIS plugin (PostGIS Topology Editor) you can > >> select all nodes and click on a button which will drop all the ones > >> that are safe to drop. > > > > You're right! I'll create my topology again but with the 2.0 m tolerance, > > then run > > my function for getting rid of nodes that are not at intersections and > > finally, > > I will use the approach you suggested of working with the TopoGeometry > > objects and the > > relation table to eliminate the remaining slivers. > > > > Will keep you posted on how it goes. Again, I really appreciate your > help. > > Thanks. > > > > Guillaume. > > > > > > -- > View this message in context: > http://postgis.17.x6.nabble.com/Topology-cannot-delete-slivers-or-gaps-tp5007250p5007266.html > Sent from the PostGIS - User mailing list archive at Nabble.com. > ___ > postgis-users mailing list > postgis-users@lists.osgeo.org > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users > ___ postgis-users mailing list postgis-users@lists.osgeo.org http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
Re: [postgis-users] Topology: cannot delete slivers (or gaps)
Sandro Santilli wrote >> I suggest you take a look at edges having face 1831 on either >> the right or left edge. Do any edge exist ? > > edge 5187 has face 1831 as its right face > >> The correct procedure to drop those slivers would be to assign >> those small areas to the (closest|biggest|leftmost|youpickit) >> TopoGeometry object, to one and only one, and then, if you really >> need it, drop the edge internal to the TopoGeometry. > >> I made a QGIS plugin which may help you do some of these things >> manually, which is useful in some cases, mainly to understand the >> issues. > > The plugin you made is a great tool (thanks). I will first try to get the > number of slivers down to > a manageable number, which I had with setting the tolerance at 2.0 m, and > then apply the > TopoGeometry approach above. > >> So the error was right about there being another edge attached to the >> node: > >> ERROR: SQL/MM Spatial exception - other edges connected (3912) > >> I'm guessing 3912 and 3908 are the two parallel edges in the picture >> you attached: https://dl.dropboxusercontent.com/u/5196336/example1.bmp > > You're right, they are the two parallel edges. And it's the same for most > of > the some 650 slivers I have. > >> Again, QGIS may help you getting more info out of the visual, enable >> the DBManager core plugin, select your topology schema and select >> Schema->TopoViewer from the menu. > > I didn't know about the TopoViewer tool. I was importing the topology > tables (node, edge, face) > like any other PG geometry tables. Will explore with this new tool. > > >> It's probably easier to clean up nodes for an areal topology than to >> clean up faces. With my QGIS plugin (PostGIS Topology Editor) you can >> select all nodes and click on a button which will drop all the ones >> that are safe to drop. > > You're right! I'll create my topology again but with the 2.0 m tolerance, > then run > my function for getting rid of nodes that are not at intersections and > finally, > I will use the approach you suggested of working with the TopoGeometry > objects and the > relation table to eliminate the remaining slivers. > > Will keep you posted on how it goes. Again, I really appreciate your help. > Thanks. > > Guillaume. -- View this message in context: http://postgis.17.x6.nabble.com/Topology-cannot-delete-slivers-or-gaps-tp5007250p5007266.html Sent from the PostGIS - User mailing list archive at Nabble.com. ___ postgis-users mailing list postgis-users@lists.osgeo.org http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
Re: [postgis-users] Import gpx files into Postgis db (windows)?
Hello, You can use GDAL/OGR, (ogr2ogr): http://www.gdal.org/drv_gpx.html Nicolas On 31 October 2014 18:32, dandrigo wrote: > Dear all, > > I'm working with windows 8 & postgis 2.1. > > I have several gps (gpx) files. I would like to import directly those gpx > files into my postgis database. > > What would be the easiest way? > > In advance, thank you to throw light for me. > > Regards. > > > > > -- > View this message in context: > http://postgis.17.x6.nabble.com/Import-gpx-files-into-Postgis-db-windows-tp5007255.html > Sent from the PostGIS - User mailing list archive at Nabble.com. > ___ > postgis-users mailing list > postgis-users@lists.osgeo.org > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users > ___ postgis-users mailing list postgis-users@lists.osgeo.org http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
