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check plot
Posted:
Tue Nov 02, 2010 11:00 amby chiara
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
Re: check plot
Posted:
Thu Nov 04, 2010 8:49 amby StephaneAdjemian
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.
Re: check plot
Posted:
Thu Nov 04, 2010 12:50 pmby chiara
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
Re: check plot
Posted:
Tue Nov 09, 2010 8:18 amby StephaneAdjemian
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.
Re: check plot
Posted:
Tue Nov 09, 2010 8:57 amby chiara
Thank you so much!
Chiara