[GRASS-user] v.vol.rst : doubts about parameter "zmult"

[Markus Neteler]

On Fri, Oct 3, 2008 at 9:27 AM, Eduardo corbelle
<eduardo.corbelle at gmail.com> wrote:
> Hello list:
>
> I've been working recently with v.vol.rst and I have doubts about
> the real function of the parameter "zmult": the manual says it allows
> the user to re-scale (change units of) the z coordinates of the data; but
> I obtain better results when using high values (about 20) of zmult even if
> no unit transformation (re-scaling) is needed at all (all data in metres). Could
> anyone give me a
> hint on the actual role of zmult in the interpolation process? Is it
> reasonable to use "very" high values (e.g. 100)?

Helena once told me:

Rescaling of z-coordinates is for example needed when the distances in
vertical direction are much smaller than the horizontal distances, if
that is the case, the value of zmult should be selected so that the
vertical and horizontal distances have about the same magnitude.

Might this help as explanation?

Markus