[GRASS-dev] v.to.db option=slope

[Jachym Cepicky]

hi,
On Thu, Dec 07, 2006 at 08:48:11AM -0800, Dylan Beaudette wrote:
> Interesting patch Jachym!
> 
> Out of curiosity, and not being able to extract it from the patch, how
> exactly does this approach work? Are you caclulating a slope between
> vertices of a 3D vector?

it works very simply: 
    (z_end - z_start)/length2d

so you get _approximated_ slope for whole line. e.g.

+         +
 \       /
  \     /
   `---´

would result into slope=0

> 
> Looking forward to learning more about it!
> 
> Great job,

just a small patch ;-)

> 
> Dylan

thanks

jachym

> 
> On 12/7/06, Jachym Cepicky <jachym.cepicky at centrum.cz> wrote:
> >Hallo,
> >somebody asked on IRC, how to calculate slopes for vector lines.
> >
> >This patch should add new option "slope" to v.to.db module and calculate 
> >slope steepness
> >for each vector line
> >
> >What do you think, shall I commit this patch to cvs?
> >
> >Jachym
> >--
> >Jachym Cepicky
> >e-mail: jachym.cepicky at centrum.cz
> >URL: http://les-ejk.cz
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-- 
Jachym Cepicky
e-mail: jachym.cepicky at centrum.cz
URL: http://les-ejk.cz
GPG: http://www.les-ejk.cz/pgp/jachym_cepicky-gpg.pub
-----------------------------------------   
OFFICE:                                     
Department of Geoinformation Technologies 
Zemedelska 3
613 00, Brno
Czech Republick
e-mail: xcepicky at node.mendelu.cz
URL:    http://mapserver.mendelu.cz
Tel.:   +420 545 134 514
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