#2280: v.extract: allow random extraction based on feature ids, not only
category
values
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Reporter: mlennert | Owner: grass-dev@…
Type: enhancement | Status: new
Priority: normal | Milestone: 7.0.0
Component: Vector | Version: svn-trunk
Keywords: v.extract category values random | Platform: Unspecified
Cpu: Unspecified |
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I have a point vector file over 400,000 points) without attribute table.
The one relevant info is stored as a category value in layer 1.
I would like to extract at random a subset of 50,000 points. v.extract
random= seems like the ideal solution. However, there are only 687
different category values and thus v.extract bails out with
{{{
ERREUR :Random category count is larger or equal to uniq
<point,line,boundary,centroid,area,face> feature category count
687
}}}
When I add category values to layer=2, I can then do the v.extract with
random=50000, but it only extracts layer 2, so I lose the info in layer 1.
I can see two solutions:
- allow random selection in feature id space, not only in category space
- add flag to keep info from all other layers when extracting (which then
allows to do the extraction with the extra v.category step mentioned
above)
Moritz
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Ticket URL: <https://trac.osgeo.org/grass/ticket/2280>
GRASS GIS <http://grass.osgeo.org>
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