[R-sig-Geo] Gaussian transformation

[Carlo Innocenti]

Thank you Edzer.

It works, but I need the back transformation as well.
What about the gaussian anamorphosis with hermite polynomials? I know that
is a method used to normalize the data before to apply the conditional
gaussian simulation.
There is a package in R to transform and back transform with this method?
Another method that is used in these cases should be the normal scores
transformation: is it implemented in some package?

Carlo




2015-04-28 22:32 GMT+02:00 Edzer Pebesma <edzer.pebesma at uni-muenster.de>:

> one way is the rank transform:
>
> x = rgamma(100, 0.1)
> hist(x)
> y = qnorm((order(x)/(length(x) + 0.5)))
> qqnorm(y)
>
> but transforming your conditionally simulated values back will be
> tricky. And I'm not sure about the 0.5.
>
> On 04/28/2015 06:09 PM, Carlo Innocenti wrote:
> > I would like to perform a gaussian conditional simulation on a variable
> > that is highly skewed.
> > Could someone suggest me how to transform my variable in a gaussian
> > distribution?
> >
> > Thanks,
> > Carlo
> >
> >
>
> --
> Edzer Pebesma
> Institute for Geoinformatics (ifgi),  University of Münster,
> Heisenbergstraße 2, 48149 Münster, Germany; +49 251 83 33081
> Journal of Statistical Software:   http://www.jstatsoft.org/
> Computers & Geosciences:   http://elsevier.com/locate/cageo/
> Spatial Statistics Society http://www.spatialstatistics.info
>
>
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>


-- 


Carlo Innocenti, PhD

ISPRA
Istituto Superiore per la Protezione e la Ricerca Ambientale
High Institute for Environmental Protection and Research

Via Vitaliano Brancati, 60
00144 Roma
Italy

phone: +39 06 5007 4639
email: carlo.innocenti at isprambiente.it

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