[GRASS-dev] [bug #2793] (grass) v.segment: side offset is ignored

[Markus Neteler]

On Thu, May 03, 2007 at 10:18:24PM +1200, Hamish wrote:
> > Markus Neteler via RT wrote:
> > > https://intevation.de/rt/webrt?serial_num=2793
> > > 
> > > Apparently Vect_point_on_line() lacks support for side offset.
> > > Indeed, it doesn't even have such a parameter.
> 
> Hamish:
> > if we know the slope of the line at the point (angle*), it is easy
> > enough to calculate a point perpendicular to it (in the x,y plane)
> > offset by a certain distance with a little trig.
> ..
> > with luck the line direction is ok- shift off to the left or right?
> 
> 
> see attached patch. raw & completely untested. All I know is that it
> compiles.

Will do, thanks.
 
> > can anyone compose a nicer example for the v.segment help page?
> > (v.to.points -n or -v to get points?)

Will try...

BTW: v.lrs.segment suffers from the same problem:
http://grass.itc.it/grass63/manuals/html63_user/v.lrs.segment.html
P <pid> <lid> <milepost>+<offset> [<side offset>]
L <sid> <lid> <milepost>+<offset> <milepost>+<offset> [<side offset>]

:) (hint hint)

Markus