[GRASS-user] partial vector copy to smaller territory

[Markus Metz]

On Fri, Nov 2, 2018 at 6:32 PM Frank David <frank.david at geophom.fr> wrote:
>
> Le 02/11/2018 à 14:43, Markus Metz a écrit :
>
>
>
> On Fri, Nov 2, 2018 at 11:58 AM Frank David <frank.david at geophom.fr>
wrote:
> >
> > Le 31/10/2018 à 20:57, Markus Metz a écrit :
> >
> > Hi Frank,
> >
> > On Wed, Oct 31, 2018 at 1:39 PM Frank David <frank.david at geophom.fr>
wrote:
> > >
> > > Hello Vero,
> > >
> > > Thanks for your reply. It took almost one hour to extract my area (I
guess because of topology). I do the same with Qgis from a shape in less
than 10 minutes (but with several operations)... it's may be a bad idea to
have a so heavy vector map in Grass...
> >
> > this kind of operation could be much faster in latest GRASS 7.4 than in
any previous versions. Which GRASS version are you using?
> >
> > Hello Markus,
> >
> > I'm using 7.4.1 on debian9
> >
> > But my grass db folder  is on a small server (Synology NAS), so may be
the network makes slow down the operation ?
>
> This is possible, but it should not slow it down that much: 10 min vs 1
hour
>
> Can you provide a link to the vector from which you want to extract a
small area, and the command you used to extract a small area? Maybe there
is scope for optimization.
>
> Markus,
>
> The data is CorineLandCover for france. You can download 400mo here >
https://we.tl/t-tvldlmkVw3
>
> First I have imported the shape in PERMANENT
>
> and I do : v.extract --verbose input=CLC12_FR_RGF at PERMANENT where=CODE_12
IN (111,112,131,311,312,313,324) output=clc12
>
> Hope it helps you...

import of the shapefile with v.in.ogr takes here 5 minutes
v.extract takes here 27 seconds instead of 1 hour

"here" means a laptop with Intel Core i7 4th generation and standard SATA
SSD, i.e. no fancy new high-speed system at all.

I am afraid this does not help you. What could take long is writing
attributes, depending on the database connection. I am using the default
sqlite database.

You could use top to check if v.extract is running at 100%.

Markus M
>
> Cheers,
> Frank
>
>
> Markus M
> >
> > Cheers,
> > Frank
> >
> >
> > Markus M
> > >
> > > Cheers,
> > >
> > > Frank
> > >
> > > Le 31/10/2018 à 11:26, Veronica Andreo a écrit :
> > >
> > > Check v.extract or v.clip
> > >
> > > Cheers,
> > > Vero
> > >
> > > El mié., 31 oct. 2018 7:20, Frank David <frank.david at geophom.fr>
escribió:
> > >>
> > >> Hello,
> > >>
> > >> What is the best and fast way to make a copy of a part of vector map
> > >> (national) to get a smaller territory ? (partial copy).
> > >> Thank you for your advice !
> > >>
> > >> Frank
> > >> _______________________________________________
> > >> grass-user mailing list
> > >> grass-user at lists.osgeo.org
> > >> https://lists.osgeo.org/mailman/listinfo/grass-user
> > >
> > > _______________________________________________
> > > grass-user mailing list
> > > grass-user at lists.osgeo.org
> > > https://lists.osgeo.org/mailman/listinfo/grass-user
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-user/attachments/20181102/b68d6a3f/attachment.html>