[R] mixed effect model
Martina Pavlicova
pavlicov at stat.ohio-state.edu
Thu Oct 24 23:16:39 CEST 2002
Dear all,
is it possible to fit a following mixed effect model?
Y_ij = mu + X_i * beta + b_i + b_ij + epsilon_ij
b_i ~ Gaus [ 0, sigma^2 ]
b_ij ~ Gaus [ 0, sigma_i^2 ]
where i = 1 ... M
j = 1 ... M_i
X_i is a 0/1 treatment variable (beta a scalar)
In my problem:
i ... subject
j ... voxel in subject
Note that the b_ij have different variance for each subject i.
Is it possible to fit this model using lme()?
Thank you very much.
Martina Pavlicova
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