Re: [R] unstructured correlation matrix in lme

2008-06-26 Thread David Hajage
I answer my own question. I was disturbed by the syntax of the SAS code for "proc mixed", which uses the same procedure for mixed or non mixed effect model. Moreover, the type of variance-covariance structure is indicate by one parameter. R is more intuitive and supple : there is two different fu

Re: [R] unstructured correlation matrix in lme

2008-06-25 Thread David Hajage
I would like to make clear that the SAS "unstructured" correlation matrix in the second model was : Estimated R Correlation Matrix for id 1 1 1. 0.8575 0.6984 0.4657 0.3165 2 0.8575 1. 0.8557 0.5670 0.4039 3 0.6984 0.8557 1.0

[R] unstructured correlation matrix in lme

2008-06-25 Thread David Hajage
Hello R users, I'm student and I'm actually having a lecture introducing repeated mesures analysis. Unfortunately, all examples use SAS system... I'm working with lme function (package "nlme"), and I'm using extract.lme.cov (package "mgcv") to extract covariance structure of models. One example