# Data and model blocks in JAGS

I am trying to model a function of observed data in JAGS. For example

   x[i,t]/phi ~ dpois(mu)


where x is observed and phi is a parameter in the model. I can't seem to get this working and am wondering if I may be missing some larger issue in JAGS. I am pretty sure you can't have any transformation of the data in the model statement and need to use a data block but that doesn't seem to be dynamic, thus not allowing for me to fit phi.

Any ideas?

• Can you please add the formulas for your model? – teucer Nov 7 '11 at 10:23
• it is a pretty convoluted model and I think it will complicate the question. Is my question unclear? – scottyaz Nov 7 '11 at 11:24
• I believe you cannot fit the model that you have described: to my knowledge in JAGS you are not able to scale a distribution. What distribution $\phi$ is supposed to follow? If it is simple enough, you can derive the distribution of $x$ directly and sample from it. – teucer Nov 7 '11 at 11:48
• @teucer Feel free to convert your comment to a response, so that it can be voted up and perhaps get the green mark. – chl Nov 7 '11 at 17:53