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9

Proper one-sided buffers were supposed to have landed in 1.5, but it looks to me that while the styles did land, sidedness didn't make it in. There is however a current patchset which exposes GEOSSingleSidedBuffer and performs the one-sided buffer as expected, under the name ST_OffsetCurve; see further background in ticket #413. In use: select ...


6

If you're interested in learning more about this area, the problem is named cartographic displacement, and its one aspect of cartographic generalization. A couple of articles discussing displacement and approaches for handling the problem: Bader, Matthias. 2001. Energy Minimization Methods for Feature Displacement in Map Generalization. Steiniger, S Tefan ...


5

"Simplifying and smoothing features" might help GIS Stack user Mapperz blogged about this some time ago


4

This sample creates two polygons on either side of a linestring. It requires PostGIS 1.5 or greater. I'm not sure how well it will cope with lines that cross themselves. SELECT ST_AsText(geom) FROM ST_Dump (( SELECT ST_Polygonize(GEOMUNION(ST_Boundary(ST_Buffer(the_geom, 0.5, 'endcap=flat join=round')), the_geom)) AS buffer_sides FROM (SELECT ...


3

I presume you do not actually mean editing the raw vector data but editing the cartographic representation of that data. The simple approach to representing lines that share the same location would be to change their symbology from the default Simple Line Symbol to Cartographic Line Symbol and then set an offset as required. You can then save this as a ...


3

In ArcGIS Desktop, you can use the Integrate Tool to move the vertices of two feature classes to be coincident within a certain threshhold distance. As long as you are certain your verticies are very close and carefully set your threshold distance, you can then do a Spatial Join on geometries that are unique. Note however, that this will change the ...


3

Merging your truck routes data looks complex, and it is maybe not necessary. Another approach could be the following: Retrieve some road network data for your area of interest. Maybe you already have it. Otherwise, you could get openstreetmap data on roads. Link or snap your route data to this network using some basic data matching operations. A simple ...


2

This problem is a very typical one in cartographic generalisation. Automated methods exist for that, but no implementations are available yet. Methods based on "Beams" and "Snakes" give efficient results to solve these cartographic conflicts of network data (see also the references given by scw). Here are some results of the beams algorithms on road data: ...


2

Here is another option. If you are just worried about the visualisation of these parcels, then if you import them into a File geodatabase you can then create Cartographic Representations over them. Then the cartographic representations can be easily modified so that the parcels are smoothed out. This will only work in a File Geodatabase and will mean that ...


1

Are we overcomplicating the problem? Is it simply that you want, cartographically, the lines to pass through each junction not around the junction? With that interpretation in mind, perhaps simply make the juntion points larger? If you want to actually join them in the database, buffer the junction points to sufficiently large circles and interset.


1

I know this post is a bit dated, but thought I would propose the use of another tool. Integrate allows the user to define an x,y tolerance, and is useful if "You want lines to have vertices wherever they intersect." I'm not entirely sure if it will work for this application but may warrant some investigation.


1

http://mapshaper.org/ provides an online applet to do that (see here). Polygon data are uploaded from a shp file, the simplification level can be controlled on-the-fly with a slider bar, and the simplified data can be imported. Of course, the simplification preserves the topological relationships between polygons (no gaps, no overlaps are created). It is ...



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