The place where a point will fall depends on the arguments "distribution" and
"parameters". In spatial simulated annealing we start allowing a point to be
shifted (perturbed) to any location within the study area. As the iterations go
on, we constrain the amount of shifting to shorter distances.
Regarding v.random: could you please include a description in the help page on
how the restriction is done? This is an extremely important information.
Alessandro Samuel-Rosa
---
Graduate School in Agronomy - Soil Science
Federal Rural University of Rio de Janeiro
Seropédica, Rio de Janeiro, Brazil
---
Guest Researcher at ISRIC - World Soil Information
Wageningen, the Netherlands
---
Homepage: soil-scientist.net Skype: alessandrosamuel
Em Quinta-feira, 28 de Agosto de 2014 17:28, Markus Neteler <[email protected]>
escreveu:
On Aug 27, 2014 12:12 AM, "Alessandro Samuel Rosa"
<[email protected]> wrote:
>
> Dear GRASS GIS developers,
>
> I am planning to use v.perturb to run a spatial simulated annealing exercise.
> Two drawbacks with v.perturb exist. First, "output vector points are not
> guaranteed to be contained within the current geographic region".
The command v.random got recently improved to optionally constrain points being
generated to a restricted area. Not sure if this method could be implemented
here as well.
Did you test how far outside points may fall?
> Second, all vector points are perturbed together.
Here a "where" statement would help, to be implemented...
Markus
> Is it very difficult to solve this issues?
>
> Another option for perturbation would be v.edit, but in that case the
> direction and distance are not random.
>
> Best,
>
> Alessandro Samuel-Rosa
> ---
> Graduate School in Agronomy - Soil Science
> Federal Rural University of Rio de Janeiro
> Seropédica, Rio de Janeiro, Brazil
> ---
> Guest Researcher at ISRIC - World Soil Information
> Wageningen, the Netherlands
> ---
> Homepage: soil-scientist.net Skype: alessandrosamuel
>
> _______________________________________________
> grass-dev mailing list
> [email protected]
> http://lists.osgeo.org/mailman/listinfo/grass-dev
_______________________________________________
grass-dev mailing list
[email protected]
http://lists.osgeo.org/mailman/listinfo/grass-dev
