[GRASS5] [bug #875] (grass) v.reclass does nothing...

[Markus Neteler]

Hi Alex,

On Thu, Dec 20, 2001 at 03:03:20AM -0800, Alex Shevlakov wrote:
> Hi,
> 
> it seems to me that v.reclass works as it is supposed
> to in your example:
> 
> cat fields.recl | v.reclass fields out=fields.recl
> type=area
> 
> here is the result query d.what.vect output:
>
[...] 
> So actually there are only 2 categories in fields.recl


you are right! Thanks for the good news, it seems I was confused by 
two facts

 - d.area colors according to the polygon number, not the category
   number
   Maybe we want a flag "-c" to color according to the categorry numbers
   and not to the polygon numbers?

 - v.reclass does not eliminate boundaries properly when two adjacent 
   polygons are assigned to the same category, as you also say.

[...]
> Each polygon would be colored differently (even those
> having the same new category) in d.area.

Sorry for this, as I have implemented that flag in d.area
I should have known (oops :-)

So
 d.vect.labels fields.recl
runs well.

> You can try -d option with v.reclass and get fewer
> colors in the result map, but not two. This is what I
> think strange (bug?).

Yes, this is *really* a bug. "-d" also damages the topology
in the current implementation as open polygons occur.

> To get only two polygons in the result d.area, perhaps
> you'd better use v.extract with -d. 

Yes - my intention was to test v.reclass.

Thanks for your hints,

 Markus

 
> --- Markus Neteler via RT <grass-bugs at intevation.de>
> wrote:
> > Hi Eric,
> > 
> > I tried again today, but v.reclass still produces
> > in=out results.
> > The same procedure works well with raster maps
> > (using Spearfish,
> > note that I am *not* in PERMANENT mapset):
> > 
> > cat fields.recl
> > 1 thru 62 = 1 private
> > 63        = 2 Black Hills Natl. Forest
> > 
> > cat fields.recl | r.reclass fields  out=fields.recl
> > d.rast fields
> > d.rast fields.recl
> > -> result is fine
> > 
> > cat fields.recl | v.reclass fields type=area
> > out=fields.recl
> > v.support fields.recl
> > d.area -f fields
> > d.area -f fields.recl
> > -> result is identical - oops.
> > 
> > Is it possible for you to try my example? Would be
> > great...
> > 
> > Thanks,
> > 
> >  Markus
> > 
> > 
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-- 
Markus Neteler

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