Hi,
I have a problem with the check plot. What does it mean when I can see only the loglik kernel, but not the log-post?
Thank you so much,
Chiara
Dear Chiara,
This happens because in some cases we cannot distinguish the posterior kernel and the likelihood. You will get this kind of plots if the likelihood is picked in a region where the prior is flat.
Best, Stéphane.
Thank you for your answer.
I am sorry, but I have another stupid question. Is it possible that this problem induces the result of 0 standard deviation in the posterior maximization? Which could be the causes of this problem? What I have to do?
Thank you so much,
Chiara
No, these issues are not related… Zero posterior standard deviations are generally a consequence of a failure of the optimization step. You may try the following:
(1) Change the initial condition of the optimization routine (default is the prior mode)
(2) Change the priors
(3) Change the optimization routine
Best, Stéphane.
Thank you so much!
Chiara