[GRASS-user] v.distance warning (WARNING: more cats of to_layer)

GRASS GRASS user
1

Dear friends,

what does the warning:

WARNING: more cats of to layer

mean, when you execute the command v.distance?

Best Regards
--
Corrado Topi

Global Climate Change and Biodiversity
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645, E-mail: ct529@york.ac.uk

2

Hi,

2008/3/12, Corrado <ct529@york.ac.uk>:

what does the warning:

WARNING: more cats of to layer

mean, when you execute the command v.distance?

which GRASS version are you using? I cannot find such kind of message
in grass_trunk.

Martin

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

3

[fwd to list]

Hi,

it means that given vector feature from 'to' map (layer 'to_layers')
has more then one category. Maybe it would make sense to change
warning text to something less cryptic.

Martin

2008/3/12, Corrado <ct529@york.ac.uk>:
> Dear Martin,
>
> I am using 6.2.3.
>
>
> On Wednesday 12 March 2008 13:31:49 you wrote:
> > Hi,
> >
> > 2008/3/12, Corrado <ct529@york.ac.uk>:
> > > what does the warning:
> > >
> > > WARNING: more cats of to layer
> > >
> > > mean, when you execute the command v.distance?
> >
> > which GRASS version are you using? I cannot find such kind of message
> > in grass_trunk.
> >
> > Martin
>
>
>
> Best Regards
> --
> Corrado Topi
>
> Global Climate Change and Biodiversity
> Area 18,Department of Biology
> University of York, York, YO10 5YW, UK
> Phone: + 44 (0) 1904 328645, E-mail: ct529@york.ac.uk
>

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

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

4

Hi,

in your case the vector map (given as 'to' in v.distance) contains
some areas (bunch of boundaries and centroid inside). Category number
of area is assigned to the centroid. Geometry feature (point, line,
boundary, centroid, face or kernel) can have more categories in
general. The message from v.distance warns you that there are more
categories assigned to the area (i.e. centroid) in given layer
(to_layer). The last found category in given layer is taken for
computation, maybe v.distance should be fixed to handle also multiple
categories in one layer(?)

Martin

2008/3/12, Corrado <ct529@york.ac.uk>:

Dear Martin,

I do not understand what you mean. Could you please explain?

On Wednesday 12 March 2008 14:09:46 you wrote:
> Hi,
>
> it means that given vector feature from 'to' map (layer 'to_layers')
> has more then one category. Maybe it would make sense to change
> warning text to something less cryptic.
>
> Martin
>
> 2008/3/12, Corrado <ct529@york.ac.uk>:
> > Dear Martin,
> >
> > I am using 6.2.3.
> >
> > On Wednesday 12 March 2008 13:31:49 you wrote:
> > > Hi,
> > >
> > > 2008/3/12, Corrado <ct529@york.ac.uk>:
> > > > what does the warning:
> > > >
> > > > WARNING: more cats of to layer
> > > >
> > > > mean, when you execute the command v.distance?
> > >
> > > which GRASS version are you using? I cannot find such kind of message
> > > in grass_trunk.
> > >
> > > Martin
> >
> > Best Regards
> > --
> > Corrado Topi
> >
> > Global Climate Change and Biodiversity
> > Area 18,Department of Biology
> > University of York, York, YO10 5YW, UK
> > Phone: + 44 (0) 1904 328645, E-mail: ct529@york.ac.uk

Best Regards
--
Corrado Topi

Global Climate Change and Biodiversity
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645, E-mail: ct529@york.ac.uk

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

5

Dear Martin,

does that mean that there are several areas (that is more than one) in the to
vector that satisfy the condition (for example: dmax=100) for each point in
the from vector?

On Wednesday 12 March 2008 15:23:46 Martin Landa wrote:

Hi,

in your case the vector map (given as 'to' in v.distance) contains
some areas (bunch of boundaries and centroid inside). Category number
of area is assigned to the centroid. Geometry feature (point, line,
boundary, centroid, face or kernel) can have more categories in
general. The message from v.distance warns you that there are more
categories assigned to the area (i.e. centroid) in given layer
(to_layer). The last found category in given layer is taken for
computation, maybe v.distance should be fixed to handle also multiple
categories in one layer(?)

Martin

2008/3/12, Corrado <ct529@york.ac.uk>:
> Dear Martin,
>
> I do not understand what you mean. Could you please explain?
>
> On Wednesday 12 March 2008 14:09:46 you wrote:
> > Hi,
> >
> > it means that given vector feature from 'to' map (layer 'to_layers')
> > has more then one category. Maybe it would make sense to change
> > warning text to something less cryptic.
> >
> > Martin
> >
> > 2008/3/12, Corrado <ct529@york.ac.uk>:
> > > Dear Martin,
> > >
> > > I am using 6.2.3.
> > >
> > > On Wednesday 12 March 2008 13:31:49 you wrote:
> > > > Hi,
> > > >
> > > > 2008/3/12, Corrado <ct529@york.ac.uk>:
> > > > > what does the warning:
> > > > >
> > > > > WARNING: more cats of to layer
> > > > >
> > > > > mean, when you execute the command v.distance?
> > > >
> > > > which GRASS version are you using? I cannot find such kind of
> > > > message in grass_trunk.
> > > >
> > > > Martin
> > >
> > > Best Regards
> > > --
> > > Corrado Topi
> > >
> > > Global Climate Change and Biodiversity
> > > Area 18,Department of Biology
> > > University of York, York, YO10 5YW, UK
> > > Phone: + 44 (0) 1904 328645, E-mail: ct529@york.ac.uk
>
> Best Regards
> --
> Corrado Topi
>
> Global Climate Change and Biodiversity
> Area 18,Department of Biology
> University of York, York, YO10 5YW, UK
> Phone: + 44 (0) 1904 328645, E-mail: ct529@york.ac.uk

Best Regards
--
Corrado Topi

Global Climate Change and Biodiversity
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645, E-mail: ct529@york.ac.uk

6

Hi,

it means that some of areas have multiple assigned categories, try to
open with v.digit and check categories of area centroids.

or print categories using v.category module, e.g.

v.category map type=centroid option=print layer=1

where layer is same as to_layer from your v.distance calling (probably 1)

you will find some multiple categories, e.g.

...
24
25
21/22/23/24/28
29
...

In this case v.distance use only cat '28' (last found).

Martin

2008/3/14, Corrado <ct529@york.ac.uk>:

Dear Martin,

does that mean that there are several areas (that is more than one) in the to
vector that satisfy the condition (for example: dmax=100) for each point in
the from vector?

On Wednesday 12 March 2008 15:23:46 Martin Landa wrote:
> Hi,
>
> in your case the vector map (given as 'to' in v.distance) contains
> some areas (bunch of boundaries and centroid inside). Category number
> of area is assigned to the centroid. Geometry feature (point, line,
> boundary, centroid, face or kernel) can have more categories in
> general. The message from v.distance warns you that there are more
> categories assigned to the area (i.e. centroid) in given layer
> (to_layer). The last found category in given layer is taken for
> computation, maybe v.distance should be fixed to handle also multiple
> categories in one layer(?)
>
> Martin
>
> 2008/3/12, Corrado <ct529@york.ac.uk>:
> > Dear Martin,
> >
> > I do not understand what you mean. Could you please explain?
> >
> > On Wednesday 12 March 2008 14:09:46 you wrote:
> > > Hi,
> > >
> > > it means that given vector feature from 'to' map (layer 'to_layers')
> > > has more then one category. Maybe it would make sense to change
> > > warning text to something less cryptic.
> > >
> > > Martin
> > >
> > > 2008/3/12, Corrado <ct529@york.ac.uk>:
> > > > Dear Martin,
> > > >
> > > > I am using 6.2.3.
> > > >
> > > > On Wednesday 12 March 2008 13:31:49 you wrote:
> > > > > Hi,
> > > > >
> > > > > 2008/3/12, Corrado <ct529@york.ac.uk>:
> > > > > > what does the warning:
> > > > > >
> > > > > > WARNING: more cats of to layer
> > > > > >
> > > > > > mean, when you execute the command v.distance?
> > > > >
> > > > > which GRASS version are you using? I cannot find such kind of
> > > > > message in grass_trunk.
> > > > >
> > > > > Martin
> > > >
> > > > Best Regards
> > > > --
> > > > Corrado Topi
> > > >
> > > > Global Climate Change and Biodiversity
> > > > Area 18,Department of Biology
> > > > University of York, York, YO10 5YW, UK
> > > > Phone: + 44 (0) 1904 328645, E-mail: ct529@york.ac.uk
> >
> > Best Regards
> > --
> > Corrado Topi
> >
> > Global Climate Change and Biodiversity
> > Area 18,Department of Biology
> > University of York, York, YO10 5YW, UK
> > Phone: + 44 (0) 1904 328645, E-mail: ct529@york.ac.uk

Best Regards
--
Corrado Topi

Global Climate Change and Biodiversity
Area 18,Department of Biology
University of York, York, YO10 5YW, UK
Phone: + 44 (0) 1904 328645, E-mail: ct529@york.ac.uk

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