[GRASS-user] gradient (slope) of a road

[Markus Neteler]

On Wed, Jun 1, 2011 at 10:02 PM, Francisco Calzada
<paco.calzada2000 at gmail.com> wrote:
> Thank you so much!!! Your answers were really useful.
>
> Anyway, I would like to ask you:
>
> a) the result of the option “slope” of v.to.db is expressed in degrees or in
> percent units?
>
> b) if it is in degrees is there any easy way to change it to percent?

The formula is coded like this in C:

   slope = (Points->z[Points->n_points - 1] - Points->z[0]) / len;

Calculations on attributes can be done with v.db.update when not using
the DBF driver (but SQLite or other).

Markus