[R] fix variance parameter values for lmer estimation

[Wilfried Cools]

Dear list-members,

a model is fit with lmer, but I want to force the variance parameter values
to be as defined by me

I thought, use 'start' to specify initial values and only allow for one
iteration ?
my question is how to do that ?

to specify the 2x2 matrix of variance parameter values:
start=list(groups=array(2,-0.5,1),dim=c(2,2))

now I need to make sure the mean structure is estimated, while the variance
parameter values are kept constant ??
e.g. lmer(resp~pred1+pred2+(1 +
pred1|groups),start=list(groups=array(2,-0.5,1),dim=c(2,2)),....)


cheers,

 
Wilfried
 


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