I am using rjags to conduct a Bayesian QMRA for a foodborne pathogen. One of the parameters (P) I am using is defined by a 4-parameter beta/generalized beta distribution where P~dBeta_ab(6.5, 5.7, 0, 6.8) and 0 and 6.8 are the minimum and maximum respectively. dBeta_ab is a function from the ExtDist package, but rjags does not recognize it:
RUNTIME ERROR: Compilation error on line 3. Unknown distribution: dBeta_ab
I've looked through the rjags manual and list of modules, but have not found anything that would allow me to use an existing module that would accommodate a 4-parameter beta nor have I found a way to extract and use this function within the BUGS code.