[GRASS5] do polylines share endpoints?

[Radim Blazek]

On Monday 26 April 2004 23:36, Christopher Fonnesbeck wrote:
> On Apr 26, 2004, at 12:43 PM, Radim Blazek wrote:
> >> I am trying to use v.select on a stream layer to select all stream
> >> segments connected to a chosen segment, first using v.extract:
> >>
> >> v.extract list=96 input=streams output=foo
> >>
> >> then using v.select with "foo":
> >>
> >> v.select ainput=streams binput=foo output=bar
> >>
> >> This works fine for most segments, but many segments that are clearly
> >> attached to other segments are considered by v.select to be
> >> unattached.
> >> For example, in the screen shot I have attached to this message, the
> >> red
> >> line shows the layer "bar" which by the method above should be that
> >> segment *plus* the 2 segments to which it is clearly connected.
> >> Shouldnt
> >> these three segments share an endpoint? If not, how is one supposed to
> >> select neighbours?
> >
> > Check it in v.digit (Settings -> Symbology: node (1 line), node (2
> > lines) )
> > If lines are not connected use v.clean tool=snap,break.
>
> The lines seem to be connected (see attached -- green=2 lines, red=1
> line), yet the code above does not select the main stream segment using
> one of its branches (the longer upward-pointing segment in the attached
> image).

Can you send me $MAPSET/vector/streams/coor ?

Radim