[GRASS-user] speeding up v.overlay

[Markus Metz]

Stuart Gralton wrote:
>
> This is the original vector:
>
> v.db.connect -p cont
> Vector map <cont at PERMANENT> is connected by:
> layer <1> table <cont> in database
> </home/stuart/grassdata/aawt_mga55/PERMANENT/dbf/> through driver <dbf> with
> key <cat>
>
>
> The v.split command and output:
>
> v.split input=cont output=contSplit length=10000
>
>
> Proof that there is no attribute table:
>
> v.db.connect -g contSplit
> ERROR: Database connection for map <contSplit at PERMANENT> is not defined in
> DB file
>
>
> I hope that this is this what you were after.
>
That's what I was after.

Umh, I forgot that I fixed that 4 months ago, please use a newer
version, preferably the latest weekly snapshot.

Markus M

>
> Markus Metz wrote:
>>
>> Stuart Gralton 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.spllt does copy all attribute tables. Can you post the output of
>> v.db.connect -p or v.db.connect -g for the original vector and the
>> output of v.split?
>>
>> Markus M
>>
>> >     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
>> >
>> >
>
>