[GRASSLIST:9591] Re: v.buffer: area boundary around line? Wanted: howto!

[Otto Dassau]

Am Mittwoch, 21. Dezember 2005 13:19 schrieb Wolfgang Qual:
> Hi Otto, hi list.

Hi, 

the problems I described still exist with the spearfish dataset: 

v.buffer in=roads out=roadsbuf buffer=20 type=line
v.buffer in=roads out=roadsbuf buffer=20 

it doesn't make a difference in the result.

  Otto

> Sorry, I think I was too fast...:
> If I *do not specify "type"* in the command for v.buffer (v.buffer
> in=ausschnitt out=buff_ausschnitt bufcol=gesamtbr)
> I do get a correct result. I can add this vector to my QGIS-Map (Layer
> 1_polygon) - works.
> However: how can I display this in GRASS (d.mon, d.vect)? If I try d.vect,
> the area inside the ring is also displayed!
>
> Wolfgang
>
> Buffer is drawn around the feature (line).
>
> > --- Ursprüngliche Nachricht ---
> > Von: Otto Dassau <dassau at gdf-hannover.de>
> > An: "Wolfgang Qual" <Wolfgang.Qual at gmx.net>
> > Kopie: grasslist at baylor.edu
> > Betreff: Re: [GRASSLIST:9588] v.buffer: area boundary around line?
> > Wanted: howto!
> > Datum: Wed, 21 Dec 2005 12:17:50 +0100
> >
> > Am Mittwoch, 21. Dezember 2005 11:22 schrieb Wolfgang Qual:
> > > Hi List,
> >
> > Hi,
> >
> > > I tried to create a new area boundary around a line theme. Thought it
> >
> > would
> >
> > > be easy to do it like this:
> > >
> > > v.buffer in=ausschnitt out=buff_ausschnitt bufcol=gesamtbr
> > > type=boundary
> >
> > I also tried with the spearfish location and a CVS snapshot from today
> > and got
> > similar strange results, where the lines (roads) describe a closed ring.
> >
> > v.buffer in=roads out=roadsbuf buffer=20 type=line
> >
> >
> >   Otto
> >
> > > But GRASS won't create a new theme. After that, I tried to first create
> >
> > a
> >
> > > line buffer theme (works fine) and then convert it to a area boundary
> >
> > theme
> >
> > > using v.type. However, the new area boundary theme does not have the
> >
> > shape
> >
> > > of the line buffer theme.
> > >
> > > BTW, the line theme looks like this (street network):
> > >
> > >   ------------------
> > >
> > >     |         |       ...but I get s.th.      XXXXXXXXXXXX
> > >     |         |       like this:              XXXXXXXXXXXX
> > >
> > >   --------------                              XXXXXXXXXXXX (area
> > > inside)
> > >
> > > I would greatly appreciate to receive some hints...
> > >
> > >
> > > Best wishes,
> > > Wolfgang
> >
> > --
> > GDF Hannover - Solutions for spatial data analysis and remote sensing
> > Office Hannover     -      Mengendamm 16d    -     D - 30177 Hannover
> > Internet: www.gdf-hannover.de,               Email: info at gdf-hannover.de
> > Phone : ++49.(0)511.39088507,              Fax: ++49.(0)511.39088508

-- 
GDF Hannover - Solutions for spatial data analysis and remote sensing
Office Hannover     -      Mengendamm 16d    -     D - 30177 Hannover
Internet: www.gdf-hannover.de,               Email: info at gdf-hannover.de
Phone : ++49.(0)511.39088507,              Fax: ++49.(0)511.39088508