[GRASS-user] Can't dissolve based on column? -- Merging tiles with unequal column number with v.patch (?)

Martin Landa landa.martin at gmail.com
Wed Jan 16 16:53:36 EST 2008


Hi,

2008/1/16, Nikos Alexandris <nikos.alexandris at felis.uni-freiburg.de>:

> Now I remember also why I merged with ogr2ogr outside of grass.
>
> Because 2 of the tiles (I downloaded yesterday) have more columns than
> usual.
>
> So with v.patch I get:
>
>  v.patch -e `g.mlist type=vect pat="E*" sep=,` out=clc00_patched
> ERROR: Number of columns differ.
>
> How can I override this?

v.patch simply requires table structures to be identical. This
limitation can be removed, but it requires some changes in the code...

Martin

> On Wed, 2008-01-16 at 21:54 +0100, Nikos Alexandris wrote:
> > My column "CODE_00" was identified as "TEXT", not "varchar". So maybe
> > this was the problem (?)
> >
> > I merged the tiles outside of GRASS with ogr2ogr -update -append... etc.
> >
> > I did not try to merge with v.patch the tiles.
> >
> > Is there a difference?
> >
> > On Wed, 2008-01-16 at 21:53 +0100, Martin Landa wrote:
> > > Hi,
> > >
> > > I tried to dissolve vector map based on text column (varchar). Seems to work.
> > >
> > > e.g.
> > >
> > > v.db.addcol vegcover col="label1 varchar(250)"
> > > echo "update vegcover set label1='a'" | db.execute
> > > v.dissolve in=vegcover out=vc_dis --o col=label1
> > >
> > > Martin
> > >
> > > 2008/1/16, Martin Landa <landa.martin at gmail.com>:
> > > > Hi,
> > > >
> > > > 2008/1/16, Patton, Eric <epatton at nrcan.gc.ca>:
> > > > > Just a clarification...so it's the case that the column parameter in v.dissolve must always be of type integer, and *only* integer?
> > > >
> > > > I don't see any reason why v.dissolve should support only integer
> > > > columns as a key used to dissolve areas...
> > > >
> > > > (not tested v.dissolve)
> > > >
> > > > Martin
> > > >
> > > > > ~ Eric.
> > > > >
> > > > >
> > > > > -----Original Message-----
> > > > > From: grass-user-bounces at lists.osgeo.org on behalf of Nikos Alexandris
> > > > > Sent: Wed 1/16/2008 3:41 PM
> > > > > To: grass-user at lists.osgeo.org
> > > > > Subject: Re: [GRASS-user] Can't dissolve based on column?
> > > > >
> > > > > Well... I suspected it had to do with the field type of the column
> > > > > "CODE_00".
> > > > >
> > > > > Indeed... the column was "TEXT".
> > > > >
> > > > > After Daniels (Victoria) indications for a similar problem a change to
> > > > > "integer" (using sqlitebrowser) solved the problem.
> > > > >
> > > > > I suggest a clarification about that in the man page of v.dissolved.
> > > > >
> > > > > Greets...
> > > > >
> > > > > P.S. Thank you Daniel
> > > > > On Wed, 2008-01-16 at 16:52 +0100,
> > > > > nikos.alexandris at felis.uni-freiburg.de wrote:
> > > > > > All I try to do is a dissolve... and for:
> > > > > >
> > > > > > > v.dissolve input=clc00_clean output=clc00_dissolved
> > > > > > col=CODE_00
> > > > > >
> > > > > > I get:
> > > > > >
> > > > > > DBMI-SQLite driver error:
> > > > > > Cannot step:
> > > > > > SQL logic error or missing database
> > > > > >
> > > > > > ERROR: Cannot fetch data
> > > > > > ERROR: Unable to open vector map
> > > > > > <clc00_dissolved_19941 at nik> on topology
> > > > > >        level 2
> > > > > > ERROR: Vector map <clc00_dissolved> not found in current
> > > > > > mapset
> > > > > > _______________________________________________
> > > > > > grass-user mailing list
> > > > > > grass-user at lists.osgeo.org
> > > > > > http://lists.osgeo.org/mailman/listinfo/grass-user
> > > > > --
> > > > > Nikos Alexandris
> > > > > .
> > > > > Department of Remote Sensing & Landscape Information Systems
> > > > > Faculty of Forestry & Environmental Sciences, Albert-Ludwigs-University Freiburg
> > > > > .
> > > > > Tel.  +49 (0) 761 203 3697 / Fax.  +49 (0) 761 203 3701 / Skype: Nikos.Alexandris
> > > > > .
> > > > > Address: Tennenbacher str. 4, D-79106 Freiburg i. Br., Germany
> > > > >
> > > > > _______________________________________________
> > > > > 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 *
> > > >
> > >
> > >
> > _______________________________________________
> > grass-user mailing list
> > grass-user at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/grass-user
> --
> Nikos Alexandris
> .
> Department of Remote Sensing & Landscape Information Systems
> Faculty of Forestry & Environmental Sciences, Albert-Ludwigs-University Freiburg
> .
> Tel.  +49 (0) 761 203 3697 / Fax.  +49 (0) 761 203 3701 / Skype: Nikos.Alexandris
> .
> Address: Tennenbacher str. 4, D-79106 Freiburg i. Br., Germany
>
>


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


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