I am working with a 6 parameter model. Sometimes when I run it, it will crash immediately with
Exception: AdAttribEP_sg_model_namespace::write_array: eta1 is -1.66624, but must be greater than or equal to 0 (in ‘/home/ubuntu/adtech/ep-stan/src/models/AdAttribEP_sg.stan’ at line 213)
other times, it will start and dump out lots messages about rejecting the draw
Informational Message: The current Metropolis proposal is about to be rejected because of the following issue:
Exception: validate transformed params: eta1 is -0.00213054, but must be greater than or equal to 0 (in ‘/home/ubuntu/adtech/ep-stan/src/models/AdAttribEP_sg.stan’ at line 213)
why the different behaviors? in particular, why stop running immediately?
As I add even more parameters, it consistently crashes right away. I need to figure this out to get it running. The only complexity really is the use of transformed parameters. I declared a number of parameters phi[dim], then declared transformed parameters like alpha1,2,3 and eta1, 2, 3, and set them equal to the phi’s. At the end, I also introduced arrays, like alpha, and set the array alpha parameters to alpha1, alpha2, etc. Is that detrimental to the model?