Tagged Questions
7
votes
1answer
360 views
How to Simplify a Line Network Preserving Topology?
I have a Shapefile (consisting of European major roads) with about 250.000 Segments which I have to simplify for pgrouting. But I can't seem to find a way to do that properly.
This is what it looks ...
5
votes
1answer
631 views
Why do simplify polygon results differ between ArcGIS and PostGIS?
I am mainly interested in why and how the Simplify Polygons tool in ArcGIS handles the simplification process, including preventing and resolving topological errors better than the equivalent ...
10
votes
3answers
538 views
How to simplify a routable network?
I have a network graph that I need to simplify in the sense of reducing the number of edges. The idea would be to merge nodes that are located close together and remove the connecting short edges.
...
12
votes
3answers
950 views
Meaning of Simplify's tolerance parameter
The standard parameters of Douglas-Peucker's simplify algorithm are geometry and tolerance (e.g ST_Simplify in PostGIS). What's the meaning of the tolerance parameter? I know that the bigger the ...
10
votes
4answers
712 views
Large shapefile to raster
I have a large shapefile (1 gb) and need to rasterise it. I have tried the following already.
1.) Import it into GRASS using v.in.ogr this failed with the error message: ERROR: G_realloc: unable to ...
6
votes
1answer
349 views
How to use simplify()
i have my Vector Data saved in a PostgreSQL PostGIS enabled Database.
The Data im displaying is very detailed, i want to simplify it through the simplify() method of Postgis.
I duplicated one of my ...
11
votes
4answers
2k views
Simplifying adjacent polygons
I encountered a problem simplifying set of polygons that are adjacent. If I simplify each polygon separately with the Douglas–Peucker algorithm (which is used by many open source tools), the resulting ...
10
votes
4answers
2k views
Simplifying polygons to linestring
I would like to simplify some polygons that represent rivers into linestrings. I assume that holes in polygons can be omitted. Anybody has some good idea how to simply do it?
It would be nice, if it ...
