I'm trying to see if I can use NIMBLE for a multinomial mixture model with removal sampling data. I followed AHM1 section 7.6 for the Poisson formulation of the multinomial in JAGS instead of the more 'general' formulation of:
y[i, 1:x] ~ dmulti(probs[i, 1:x], N[i])
N[i] ~ dpois (lambda[i])
because 'this construction does not work in BUGS because a random sample size argument is not allowed in the multinomial distribution.' So, I tried fitting this construction in NIMBLE and had no issues until running the MCMC. A slice sampler is assigned to all latent abundance states N and I get warnings for every single node as follows:
Warning: slice sampler reached maximum number of contractions for 'N[5, 17, 8]'. Current parameter value is 2.
I'm not sure what this means and couldn't find this error on this forum. So the previous steps of building and compiling the model are fine but running the MCMC is giving trouble. Is NIMBLE like JAGS that this formulation won't work, or am I making an error elsewhere? By the way, I am initialising N with the total captures at a given site plus a constant, to make sure the model doesn't initialise N to be less than the total number of captures.
Can provide code of course if necessary.