[R] mixed effect model

Martina Pavlicova
Thu, 24 Oct 2002 21:16:39 -0000

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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Department of Statistics             Office Phone: (614) 292-1567
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The Ohio State University            E-mail: pavlicov at stat.ohio-state.edu
Columbus, OH 43210-1247              www.stat.ohio-state.edu/~pavlicov



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