[R-sig-ME] help creating spatial autocorrelation structure

[Agustin Alesso]

Hello dear readers,

I'm working with nlme package and I need to create a double-spherical
correlation structure to include into my ANOVA-GLS model. As Pinheiro &
Bates suggests in their book ("Mixed-effects models in S and S-Plus",
2000, Springer), I have to create a corSpatial constructor and at least
methods for 'coef', 'corMatrix' and 'Initialize' functions.
I'm a (pre)intermediate user of R, so I'd appreciate if someone could
send me and example of how to create a croSpatial class and those
methods (commented code would be great).

Thanks in advance!

Best regards,

-- 
Ing. Agr. Agustín Alesso
Dpto. Ciencias del Ambiente
Fac. Cs. Agrarias - UNL
Kreder 2805 - S3080HOF - Esperanza
Tel: 03496-428575 int 337/256