[GRASS-user] bypassing topology (re)generation.
Milton Cezar Ribeiro
miltinho.astronauta at gmail.com
Fri Nov 14 07:22:28 EST 2008
Dear all
I have a shapefile which have a lot of polygons, many of them overlapping
other polygons.
O ArcGis, if I select one polygon by attribute I can highlight only the
polygon of interest.
Now I need input it on GRASS, but when I use "v.in.org input=... output=..."
the GRASS
(re)generate the topology of my polygons, breaking they by every overlapping
region.
So, from 1400 polygons now I get about 100,000 areas. And the command not
finish after hours.
My question is if I really need to (re)generate the topology leaving grass
split my original polygons
on a lot of small pieces. I really need to keep the polygons as AREA
(?boundary?) because I will
v.to.raster it after.
By the way, I used "v.in.ogr -c ..." and the "-c" flag made the process to
be very fast. But I get only
lines (not area) and donĀ“t know why my polygons appear to be shifed after I
v.extract by attribute.
Any help are very welcome.
Best wishes
miltinho
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