[GRASS-user] speeding up v.overlay

[Mark Seibel]

Using the v.select module first to limit the number of features
clipped often helps speed up the intersection process.

Mark

On Mon, Aug 23, 2010 at 8:45 AM, Stuart Gralton <sgralton at gmail.com> wrote:
> Hello Everyone,
>
> I am trying to use v.overlay to clip contour lines for a specific area. The
> contour lines were imported into GRASS from a shapefile which is about 33Mb.
> The query was as follows:
>
> v.overlay ainput=contour atype=line binput=boundingbox output=contour_clip
> operator=and
>
> The operation took 16 hours to complete, which seems excessive. Is there
> anything that I can do to speed things up?
>
> I am aware of v.split, v.select, v.clean as suggestions from other posts as
> ways of increasing performance. Unfortunately none of these helped me very
> much:
>
>     v.split seems to drop the attribute table (but it has amazing effects on
> performance).
>     v.select helps a little, but due to the nature of the data, not many
> features are removed.
>     v.clean did not have any effect. The data is from the government, and is
> already of high quality.
>
>
> Is there anything that I am missing? Or is there any way to preserve the
> attribute table when using v.split?
>
> Thanks in advance,
> Stuart
>
>
> _______________________________________________
> grass-user mailing list
> grass-user at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/grass-user
>
>