[GRASS-user] bypassing the "arrowhead" problem of ps.map

[Vincent Bain]

Hi Hamish,

Le dimanche 03 mars 2013 à 13:22 -0800, Hamish a écrit :
> Vincent wrote:
> > maybe among you some people deplore the absence of easy
> > solution in ps.map for line-end symbology, e.g. adding arrow
> > heads to lines.

my poor knowledge of C dissuaded me to investigate in this way...


> another self-hack possibility is to extract the start/end nodes
> to a points file, then, maybe with the help of v.generalize,
> find the trend direction (azimuth) at those two ends, and use
> vpoints or point instruction there with appropriate rotation
> angle.

in a way (except recourse to v.generalize), this is what is performed in
my stack of commands.

> You'll probably need to make your own symbol, but that's
> pretty easy.
> 

Here again it points to the power of ps.map. With a couple of postscript
lines you can do nearly whatever you want.

Yours,
Vincent