[R-sig-Geo] Group-wise error variance and autocorrelation

[Tim Keitt]

Sorry, I've got Pinheiro and Bates sitting on my desk and should have
reread some chapters before posting -- it looks like I can accomplish
the task by building some custom pdMat classes.

THK

On 7/19/07, Santiago Beguería Portugués <sbegueria at eead.csic.es> wrote:
> Hi Tim,
>
> The nlme package allows to model the variance structure of the
> within-group errors. It also allows to include spatial correlation
> structures, in principle it is possible to define a grouping factor too,
> although I've never used it.
>
> Santiago Beguería Portugués
>
>
> > Date: Wed, 18 Jul 2007 10:09:34 -0500
> > From: "Tim Keitt" <tkeitt at gmail.com>
> > Subject: [R-sig-Geo] Group-wise error variance and autocorrelation
> > To: "R geostat list" <r-sig-geo at stat.math.ethz.ch>
> > Message-ID:
> >       <6262c54c0707180809v4b7a1318o2547c793f5e45e48 at mail.gmail.com>
> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed
> >
> > I'm trying to specify a model where the fixed effects are
> >
> > dep ~ group + group:indep
> >
> > and the error variance and spatial autocorrelation vary by group. I've
> > tried lme but AFAICT it only supports heteroscedasticity and
> > autocorrelation within groups. Any pointers?
> >
> > THK
> >
> >
>
>
> --
>
> ---------------------------------
>
> _PLEASE, TAKE NOTE OF MY NEW EMAIL_
> _ADDRESS AND CONTACT DETAILS!_
>
> Santiago Beguería Portugués (PhD)
>
> Researcher
>
> Estación Experimental de Aula Dei - CSIC
> (Aula Dei Experimental Station,
> Spanish National Research Council)
>
> Campus de Aula Dei,
> Avda. Montañana, 1005
> 50059 - Zaragoza (Spain)
>
> P.O. Box 202, 50080 - Zaragoza (Spain)
>
> T (+34) 976 716 107
> T (+34) 976 716 100 / ext. 2356
> F (+34) 976 716 145
>
> http://www.santiagobegueria.net
>
>
>
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo at stat.math.ethz.ch
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>
>
>


-- 
Timothy H. Keitt, University of Texas at Austin
Contact info and schedule at http://www.keittlab.org/tkeitt/
Reprints at http://www.keittlab.org/tkeitt/papers/
ODF attachment? See http://www.openoffice.org/