[gdal-dev] Clipping shapefiles

[Craig Leat]

Hi Matthew

Matthew Huck wrote:
>  Thanks for that, I seem to have something working now (or so I think), my
> shape file is the contours lines for a reasonably hilly area (100Mb), and
> I'm clipping it to an area of about 1/12.  The only thing is it's still
> running about 17 hours later. Is v.overlay slow or have I done something
> wrong, here are my steps:
>
> g.region vect=NZMG_s27
> v.in.region output=cutter type=line --overwrite
> v.overlay ainput=wellington_contours atype=line binput=cutter output=clipped
> operator=and

Welcome to the world of GRASS! There is a GRASS user list [1] and this
is the best place for GRASS questions.

I see that your vector called cutter is of type line. This may be a
problem, because the manual [2] says that the type for binput can only
be area. I would expect v.overlay to complain if it can't handle the
line type and so there seems to be a conflict with the manual. Could
you move this discussion over to the GRASS list and let's see what the
GRASS experts have to say?

Craig

Ps Please indicate your GRASS version. The manual reference below is
for version 6.3.

[1] http://lists.osgeo.org/mailman/listinfo/grass-user
[2] http://grass.itc.it/grass63/manuals/html63_user/v.overlay.html