[GRASS-user] Using shapefiles

[Hamish]

Jose Gomez-Dans wrote:

> I have tried a simple shapefile (<800 polygons), and the import stage
> takes a long time (6.0.1), close to 10 minutes. Is there a
> step-by-step guide on how to quickly import a shapefile (whose extent
> you don't know), and display it?

re. "quickly"

v.in.ogr may take a long time if the data contains long complicated
polylines. Once in GRASS format v.split can be used to break the lines
to something smaller. v.in.ogr hasn't got this yet.

http://freegis.org/cgi-bin/viewcvs.cgi/grass6/doc/vector/TODO
============================
v.in.ogr
--------
It would be useful to split long boundaries to smaller
pieces. Otherwise cleaning process can become very slow because
bounding box of long boundaries can overlap large part of the map (for
example outline around all areas) and cleaning process is checking
intersection with all boundaries falling in the bounding box.
============================



generic:
v.in.ogr dsn=mapname.shp out=mapname
g.region v=mapname
d.vect mapname type=area


Hamish