I have some simple time to event data, no covariates. I was trying to fit a Weibull distribution to it. So I have the following code. Everything looks good until I load my initials. It says "this chain contains uninitialized variables". But I don't understand. I think Weibull dist only has 2 parameters, and I already specified them all. Could you please advise? Thanks!
model
{
for(i in 1 : N) {
t[i] ~ dweib(r, mu)I(t.cen[i],)
}
mu ~ dexp(0.001)
r ~ dexp(0.001)
}
# Data
list(
t.cen=c(0,3.91,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,21.95,23.98,33.08),
t=c(2.34,NA,5.16,5.63,6.17,6.8,7.03,8.05,8.13,8.36,8.83,10.16,
10.55,10.94,11.48,11.95,13.05,13.59,16.02,20.08,NA,NA,
NA),
N=23
)
# Initial values
list(
r=3,mu=3
)
The other uninitialised variables are the missing (NA) values in the vector of t. Remember that the BUGS language makes no distinction between data and parameters, and that supplying something as data with the value NA is equivalent to not supplying it as data.