v.net.path example - was Re: [GRASS-dev] Re: d.vect changes

[Markus Neteler]

On Thu, May 03, 2007 at 07:56:17AM +0200, Otto Dassau wrote:
> Hi Markus,
> 
> On Thu, 3 May 2007 07:47:59 +0200
> Markus Neteler <neteler at itc.it> wrote:
> 
> > On Thu, May 03, 2007 at 03:01:46PM +1200, Hamish wrote:
> > > Markus wrote:
> > > > d.vect kills x0
> > > ..
> > > > strace d.vect myroads_net col=red
> > > 
> > > don't know, can you reproduce it with a spearfish map?
> > > make distclean? ;)
> > 
> > It happens with Spearfish. Just try my new v.net.path
> > example in the description.html.
> > 
> > BTW: the v.clean step therein fails - it does NOT properly
> > connect the lines. Sigh.
> 
> I don't know your example,

It is in the manual page of v.net.path (CVS).

> but I had similar problems some time ago because I
> used a wrong tool order. As far as I remember the one below worked for me
> and connected all lines.
> 
> v.clean in=xx out=xx tool=snap,break thres=xx

Indeed, this helps. To me the order of snap,break isn't much
intuitive but well.

Unfortunately, even though that the map looks ok in v.digit,
v.net.path fails to navigate (but d.path does!):

...
dglShortestPath error: Head Node Not Found
WARNUNG: Point with category [10] is not reachable from point with category
         [9]
WARNUNG: [1] destinations unreachable (including points outof threshold)
...

However, the cats are correct:
d.vect myroads_net disp=shape,cat type=point

Maybe someone could try the example?

thanks
Markus