Tagged Questions
1
vote
0answers
26 views
Joining layers with respective elements with PostGIS Topology
Recently I have started using PostGIS topology extension, but I have some difficulties in understanding how the structure works:
One of the key points is the use of "layer"s: as of what I understand, ...
2
votes
4answers
131 views
How can I create polygons of the area surrounded by roads / lines?
I'm currently trying to create polygons that represent the areas surrounded by roads. The roads are stored in PostGIS as points / lines so I have flexibility over what I can do with them.
I'm ...
8
votes
1answer
152 views
How to add topology to PostGIS 2.0?
I have installed PostGIS 2.0 and need new topology but it doesn't seem installed by default. I found a lot of command line to install postgis 2.0 with topology but is there a way just to add topology?
...
4
votes
1answer
274 views
How you can repair invalid topology errors within postgis?
I've imported the shapefile of corine land cover project to my postgis database and the
select gid, ST_IsValidReason(geom) from gis.clc2000 where not ST_IsValid(geom);
returns in every occasion
...
8
votes
2answers
374 views
How to speed up space partitioning in postgis?
I've a bunch of overlapping polygons and I'm trying to partition the space to avoid having overlapping ones. I think my problem is fairly simple.
Using some ESRI product and ...
16
votes
1answer
863 views
What's the status of Postgis 2.0 topology support in QGIS?
Having followed the Postgis developments over the past 6 months I have noticed a bunch of features which seem to be incredibly cool especially in the area of topologies and associating calculations on ...
7
votes
1answer
1k views
Ring Self-Intersections in PostGIS
This is a follow on from previous question. You will see I am a new PostGIS user.
I have looked at the validity of the topology in my data and find around 1700 topology issues in the landcover ...
13
votes
1answer
568 views
Identifying topological relationships using PostGIS
I'm trying to perform a basic typology analysis using PostGIS. My objective is to find any polygons that touch other polygons. To do this, I thought the ST_GetFaceEdges would work
(reference). I want ...
5
votes
2answers
493 views
What does 'building topology' mean for pgRouting?
From a couple of answers at gis.stackexchange.com and at the pgRouting mailing list I have found out that pgRouting 'builds topology'. What does that mean?
If for example we import an .osm file into ...
6
votes
1answer
604 views
How to preserve topology while editing polygons in OpenLayers?
I’m facing this issue: I have a chloropleth map based on a set of polygons with some data. Using WFS-T (postgis, geoserver, openlayers) I am able to edit the geometry of the polygons. This works fine.
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