[GRASS-user] Duplicate vector removal

[Martin Landa]

Hi Andre,

2007/11/20, Andre Hauptfleisch <ahaupt at gmail.com>:
> Thanks for the reply Martin. I thought it might have something to do with
> the category values.
>
> I know it is easier said than done, but isn't there a way one can skip the
> category merger part? Or can I merge all the lines into a single category?
> My system doesn't require the use of category values.
>
> I would like to automate the process. At the moment I have a raster image
> with some lines in them. I convert these to a vector layer, clean it up a
> bit and output it to svg.

not sure if I understand well, you can remove categories after
cleaning vector map layer

v.category opt=delete

?

Martin

> Regards,
> Andre
>
>
>
>
>
> On Nov 20, 2007 2:03 PM, Martin Landa <landa.martin at gmail.com> wrote:
> > Hi,
> >
> > 2007/11/20, Andre Hauptfleisch <ahaupt at gmail.com>:
> >
> > > Good day,
> > >
> > > I used the v.clean approach to snap some vectors to each other. This
> caused
> > > a number of vectors to lie on the same line. The rmdupl option does not
> seem
> > > to remove these short segments.
> > >
> > > Any ideas on how I can get rid of them? Or perhaps I'm just using
> v.clean
> > > wrong. Here is the command:
> > >
> > > v.clean input=scene01 at test output=scene01_clean type=line
> > > tool=snap,rmdupl,rmsa thresh=15 --overwrite
> >
> > rmdupl removes only *identical* features, for example
> >
> > L  2 1
> >  594233.1875  4921026.59375
> >  596956.11875847 4921515.74307787
> >  1     1
> > L  2 1
> >  596956.11875847 4921515.74307787
> >  599775.5     4922022.21875
> >  1     2
> > L  2 1
> >  594233.1875  4921026.59375
> >  599775.5     4922022.21875
> >  1     3
> > L  2 1
> >  595793       4918172.46875
> >  603426.125   4919400.40625
> >  1     4
> > L  2 1
> >  595793       4918172.46875
> >  603426.125   4919400.40625
> >  1     5
> >
> > after rmdupl
> >
> > L  2 1
> >  594233.1875  4921026.59375
> >  596956.11875847 4921515.74307787
> >  1     1
> > L  2 1
> >  596956.11875847 4921515.74307787
> >  599775.5     4922022.21875
> >  1     2
> > L  2 1
> >  594233.1875  4921026.59375
> >  599775.5     4922022.21875
> >  1     3
> > L  2 2
> >  595793       4918172.46875
> >  603426.125   4919400.40625
> >  1     5
> >  1     4
> >
> > First two lines 'lie' on the third one, but they are not identical, if
> > you want to remove them, you need to merge them first. E.g.
> >
> > v.edit dupl1 tool=merge cat=1,2
> >
> > remove vertex from line
> >
> > v.generalize in=dupl1 out=dupl2
> >
> > and then run v.clean.
> >
> > The result is
> >
> > L  2 3
> >  594233.1875  4921026.59375
> >  599775.5     4922022.21875
> >  1     1
> >  1     2
> >  1     3
> > L  2 2
> >  595793       4918172.46875
> >  603426.125   4919400.40625
> >  1     5
> >  1     4
> >
> > Martin
> >
> >
> > > Thanks!
> > >
> > > --
> > > Groete,
> > > Andre Hauptfleisch
> > >
> > > M: 082 5722 469
> > > F: 086 687 1106
> > > E: ahaupt at gmail.com
> > > _______________________________________________
> > > grass-user mailing list
> > > grass-user at lists.osgeo.org
> > > http://lists.osgeo.org/mailman/listinfo/grass-user
> > >
> > >
> >
> >
> > --
> > Martin Landa <landa.martin at gmail.com> * http://gama.fsv.cvut.cz/~landa *
> >
>
>
>
> --
>
> Groete,
> Andre Hauptfleisch
>
> M: 082 5722 469
> F: 086 687 1106
> E: ahaupt at gmail.com


-- 
Martin Landa <landa.martin at gmail.com> * http://gama.fsv.cvut.cz/~landa *