v.cutter ?bug?

[Stefan.Neumann at agrar.uni-giessen.de]

Hi all,


for reducing the volume a rather large vectormap (16.000 polygons) I wrote a grass5-script which 
1. automatically generates a rectangle around the current region (works at least with tmerc,lat/long,lambert-projection)
2. cuts the original map with v.cutter
3. runs v.spag -i and v.support 

This works fine, but only sometimes. I cut country outlines, DEM-contours (created with r.contour) and a map with soil properties and I noticed that the size of the region seems to influence v.cutter. If, for example, i cut parts of the coastline of norway, v.cutter works for a region with a maximum width of 6 geographic degrees, a wider region produces an empty vector file. The DEM-contour-map, which seems to contain much more data, can be cut using a region of any size.

Thus it appears that certain combinations of datafile and cutterfile cause v.cutter to generate no vectors at all. I don't see any rule as to when it works an when it doesn't so I think that this might be some bug in v.cutter.



greetings, Stefan
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