Linked Questions

3
votes
0answers
138 views

How to simplify polygon shapefile and maintain topology? [duplicate]

I'm looking for a straightforward answer that actually works...not a 'duplicate question' flag. None of the other solutions posted in similar threads actually work...they all have dead-end answers and/...
10
votes
4answers
11k views

Simplifying adjacent polygons using QGIS “Simplify Geometries” tool

I have a big Shapefile with 200,000 polygons but the file is too big for the application that will use it. I would like to generalise these polygons and create much smaller file. I have tried to do ...
4
votes
2answers
2k views

Simplify/generalize Polygons and keep topology of different layers PostGIS/QGIS

i have some polygons of a country, states, districts, communities and i want to simplify the geometry. i already simplified the geometry of each layer but afterwards of course it doesnt fit with the ...
5
votes
2answers
5k views

What am I doing wrong with QGIS v.clean?

I thought I understood how the GRASS v.clean tool worked in QGIS (in 2.6.1 Brighton) but I keep getting unexpected results and errors with a polygon ShapeFile. I've run the QGIS TopologyChecker with ...
6
votes
1answer
805 views

Generalize large polygon-file

I have a large polygone file with landuse information (6 classes). Its vectorised from a raster classification so the polygons are all angular. Any of my tries to generalize with v.generalize (sneaks, ...
3
votes
1answer
383 views

How to use GRASS Generalize to reduce GADM data size to 1/5 preserving topology?

The GADM is a great resource from global boundaries of countries, states and municipalities. The amount of detail is suitable for many analyses but when it comes to mapping or displaying it is often ...
1
vote
1answer
534 views

Acquiring administrative country border data with a given resolution

I want to be able to find out which country a given (lat,long) pair falls into, but I don't need this to be extremely accurate and especially coasts can be quite crude as false positive hits will be ...
2
votes
1answer
466 views

Generalizing (simplifying) polygon shapefile or feature class in ArcMap while preserving topology?

I came across Generalizing polygon file while maintaining topology in QGIS? which asks for a QGIS solution to my exact question. I'm trying to do this in ArcMap. I start with a polygon shapefile (...
1
vote
1answer
199 views

Simplified polygons have overlapping lines

I am working with QGIS. I am creating a contour world map, I started my project with a raster image of the world and then extracted contour lines much too complex for my purposes. I simplified the ...
1
vote
0answers
105 views

Geopandas simplify results in gaps between polygons

The goal is to simplify the geometries of a shapefile containing multipolygons. However, when I use Shapely's simplify in geopandas, the result contains gaps between the polygons. I was hoping that ...
1
vote
0answers
73 views

How to generalize shape with PyQGIS without much Distortion in the shape?

I was trying to generalize the the inner boundaries of the polygon. Looking for a PyQGIS solution for that any other possible python solution will be fine. I tried convex hull and simplify geometry ...