[R-sig-ME] Specification of design matrix for random effects (Z)

[ONKELINX, Thierry]

Dear James,

I don't think that it is possible with lme4. But it is a Bradley Terry model, so:

library(sos)
findFn("bradley terry")

Best regards,

Thierry

ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature and Forest
team Biometrie & Kwaliteitszorg / team Biometrics & Quality Assurance
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-----Oorspronkelijk bericht-----
Van: r-sig-mixed-models-bounces op r-project.org [mailto:r-sig-mixed-models-bounces op r-project.org] Namens James Hughes
Verzonden: woensdag 2 mei 2012 1:24
Aan: r-sig-mixed-models op r-project.org
Onderwerp: [R-sig-ME] Specification of design matrix for random effects (Z)

Hello

I would like to specify the following model using lmer:

Y_ij ~ Binomial(N,p_ij)

p_ij = u + b_i + b_j

where b ~ N(0,s^2).

For example, for the 5 observations (Y_12, Y_13, Y_23, Y_14, Y_24) the random effect vector would be b = (b_1, b_2, b_3, b_4) and the design matrix for the random effects (Z) would be

Z <- matrix(c(1,1,0,0, 1,0,1,0, 0,1,1,0, 1,0,0,1, 0,1,0,1),5,4,byrow=T)

Can such a model be specified in lmer? Thanks for your thoughts.

Jim

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