[GRASS5] v.out.ogr question

[Otto Dassau]

Radim Blazek schrieb:
> 
> On Wednesday 17 March 2004 18:23, Markus Neteler wrote:
> > On Fri, Mar 12, 2004 at 05:58:40PM +0100, Otto Dassau wrote:
> > > Hi,
> > >
> > > I used the module v.out.ogr in GRASS5.7 to export polygons but missed
> > >
> > > the parameter 'type=area'. The result was a warning:
> > > > WARNING: Requested types: points and lines, but (additionally) areas
> > > > found. Check 'type' parameter.
> > > > 3426 features written
> > > > WARNING: 3426 features without category written
> > >
> > > but the map was also exported with lines instead of areas. I don't
> > > understand why the module explains a mistake but still exports
> > > the data. Wouldn't it make more sense to simply stop after warning,
> > > so the user has to add/modify the missing parameter?
> >
> > Otto,
> >
> > I have made a test with a map containing a single area:
> >
> > v.info ammprv | grep Number
> >
> >  |   Number of points:       0               Number of areas:      1     |
> >  |   Number of lines:        0               Number of islands:    1     |
> >  |   Number of boundaries:   1               Number of faces:      0     |
> >  |   Number of centroids:    1               Number of kernels:    0     |
> >  |   Number of dblinks:      1                                           |
> >
> > GRASS 5.7.-cvs:~/test > v.out.ogr ammprv dsn=ammprv layer=ammprv
> > WARNING: Requested types: points and lines, but (additionally) areas found.
> >          Check 'type' parameter.
> > 1 features written
> > WARNING: 1 features without category written
> >
> > -> Strange: I would expect 0 features written.
> 
> Why strange? Requested type is 'line,boundary' (default) and there is 1 boundary
> in ammprv and that boundary is exported.

Hi Radim, 

I simply think it would be nice, if v.out.ogr doesn't export any data,
as long as 
the parameter 'type' is not set correctly. This would just make sure,
that the user 
really gets what he intends. I know it is not an error, more a whish and
maybe also 
too petty.

  Otto