# JAGS array indexing [closed]

I have a relatively simple multivariate response problem that seems to causing me problems with array indexing. I've scraped/rewworked the model program down to the bare essentials and hopefully haven't cut/replaced too much. I hav3 265 total observations, 5 different groups of responses, each with 53 replications.

# Notes:
# N= total number of samples = 265
# K= number of clusters = 5
# T = number of observations in each clusters =53
# P = nterms=number of independent variables = 10
#
model {
for (j in 1:K) {   #K
for (i in 1:T) {  #T
y[i,j] ~ dnorm(mu[i,j], tau)
mu[i,j]<-  b0 + b[1]*x[i,j,1] + b[2]*x[i,j,2] + b[3]*x[i,j,3] + b[4]*x[i,j,4] +     b[5]*x[i,j,5] + b[6]*x[i,j,6] + b[7]*x[i,j,7] + b[8]*x[i,j,8] + b[9]*x[i,j,9] + b[10]*x[i,j,10]   # error
#            mu[i,j]<-  b0 + b[1]*x[i,j,1]+ b[2]*x[i,j,2]  # no error
}
}
# mean <- b0+ inprod(x[i,j,], beta[])
# priors ------------------
b0 ~ dnorm(0,0.001)  # prior on constant term
for(i in 1:nterms) {
b[i] ~ dnorm(0,0.001)
}
tau ~ dgamma(1.0E-3, 1.0E-3)
sigma <- 1 / sqrt(tau)
}


My data input is coming from an R script (data input snippet):

input<- "GB_migration.csv"

P<-10
K <- 5
T <- 53
N <- nrow(obs.raw)
Y.raw <- obs.raw[,2]
X.raw <- obs.raw[,1:P+2]

X<-unlist(X.raw)
dim(X)<-c(T,K,P)

Y<-unlist(Y.raw)
dim(Y)<-c(T,K)


….snip ….

The error code I get when I run it with all 10 independent variables:

Error in jags.model("Migration.mod", jags.data, n.adapt = 500, n.chains = 2) : RUNTIME ERROR: Compilation error on line 10. Unable to resolve node mu[1,1] This may be due to an undefined ancestor node or a directed cycle in the graph

I feel like I'm missing something basic with the array indexing, but I cannot seem to put my finger on it. (I've un-nested as many of the vector operations as I could to try to track this down.Hopefully the code still makes sense. )

Thanks in advance for any insight. Dave

• That's an error you would get, for example, when there is something wrong with your indexing, and you have a lot of indexing so... double check it (say, remove stuff until it works) thats my tip. – Rasmus Bååth Nov 12 '14 at 20:56
• Did you pass nterms as well as P to JAGS somewhere? – conjugateprior Dec 13 '14 at 15:53
• If you add terms one by one and it fails with b[6]*x[i,j,6] (because 6>K) then incorrectly assigned matrix dimensions are the problem. – conjugateprior Dec 13 '14 at 15:55