[GRASS-user] measuring distance along a line

[Ronja Düffel]

Thanks for the fast reply, I'll try your suggestion and report back to the 
list.

Ronja 



Am Dienstag, 15. Mai 2007 13:13 schrieben Sie:
> Ronja Düffel wrote:
> > is there a possibility to measure distance along a line in grass?
>
> yes.
>
> > I have a map of a river system and I have points (given by Northing
> > and Easting) where rivers con- or diverge. Now I would like know the
> > distance between those points, measured along the course of the
> > river. Is there a possibility to do that in grass without having to
> > measure the distance by hand (i.e. using the measuring tool in the
> > display window)?
>
> Beware that this is a fractal problem and the answer is dubious!
>
>
> maybe something like:
>
> v.clean in=rivers out=river_lines tool=break
> v.db.addcol river_lines column="seg_length DOUBLE PRECISION"
> v.to.db river_lines option=length column=seg_length units=me
>
> d.vect river_lines disp=shape,attr attrcol=seg_length
>
>
> you might also look at v.segment and v.lrs.*
>
>
> Hamish