[AniMov] R: Re: Value h (smoothing parameter)

Anne Ghisla a.ghisla at gmail.com
Mon Feb 11 20:39:38 CET 2013


On Sun, 27 Jan 2013 22:07:53 +0100 (CET)
"francescoboccacci at libero.it" <francescoboccacci at libero.it> wrote:

> Thanks Anne,
> as you know i try develop Home Range Analysis using scipy module. 
> Reading the KernelUD documentation is explained how h (smoothing
> parameter) is calculated using normal kernel (gaussian):
> 
> h = Sigma*n^(-1/6)
> 
> where
> 
> Sigma = 0.5*(sd(x)+sd(y))
> 
> I compared the h value in my plugin and in motore.R module but the
> results are very different.For example for a test shapefiles :
> 
> Home Range has 83 value
> My plugin 0.4 value
> 
> The value coming from Home Range it seems strange. Do you have any 
> suggestions?

Hello Francesco, 

sorry for delay: I have been examining adehabitat code, but I have no
idea on why the two results differ so much.

If you post or link the equations you are using in your plugin I hope
that others (Clément most probably) can help you.

> Thanks
> 
> Francesco

All the best!
Anne

> >----Messaggio originale----
> >Da: a.ghisla at gmail.com
> >Data: 27/01/2013 21.53
> >A: <animov at faunalia.it>
> >Cc: "francescoboccacci at libero.it"<francescoboccacci at libero.it>
> >Ogg: Re: [AniMov] Value h (smoothing parameter)
> >
> >On Sun, 27 Jan 2013 18:08:12 +0100 (CET)
> >"francescoboccacci at libero.it" <francescoboccacci at libero.it> wrote:
> >
> >> Hi all,
> >> i'm trying to understand the value of smoothing parameter for each
> >> type of animal used by Home Range Analysis to calculate href kernel
> >> method. My question is:
> >> 
> >> is the value in the field h_ref the value of the smoothing
> >> paramater?
> >> 
> >> into the file motore.R there is these lines?
> >> 
> >> for (i in names(OutputBox[["href.volumes"]])) {
> >> 			khr.h[i] <- OutputBox$href.volumes[[i]]$h
> >> 
> >> 		}
> >
> >Hello Francesco,
> >
> >yes, field h_ref contains the smoothing parameter value calculated by
> >adehabitat function. 
> >You can check the original adehabitat function's documentation,
> >namely adehabitatHR::kernelUD function, for more details on the
> >implementation. 
> >
> >Best,
> >Anne
> >-- 
> >http://wiki.osgeo.org/wiki/User:Aghisla
> >
> 
> 



-- 
http://wiki.osgeo.org/wiki/User:Aghisla
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