Camel: Multivariate normal with structured
missing data
Tanner and Wong present a data set with missing values modeled as a bivariate normal. No closed form for the deviance of the model can be found and so no deviance node is created by the BUGS compiler. For the same reason the DIC menu is greyed-out
model
{
for (i in 1 : N){
Y[i, 1 : 2] ~ dmnorm(mu[], tau[ , ])
}
mu[1] <- 0
mu[2] <- 0
tau[1 : 2,1 : 2] ~ dwish(R[ , ], 2)
R[1, 1] <- 0.001
R[1, 2] <- 0
R[2, 1] <- 0;
R[2, 2] <- 0.001
Sigma2[1 : 2,1 : 2] <- inverse(tau[ , ])
rho <- Sigma2[1, 2] / sqrt(Sigma2[1, 1] * Sigma2[2, 2])
}
Data
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Inits
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Results