How to get the MAP from chains? about dynesty

[segasai]

The logz will not help you determine the MAP value according to my understanding (as this is cumulative evidence up to that point).
I think the only choice I can see is to take logl values and add to them logprior values that you will need to compute.

[segasai]

Hi,

It's hard to tell. given that nowhere in the dynesty code 'log_evidence' term/variable is used.
But if you have log-likelihood, uou should be able to to compute the log-posterior by adding log-prior to it. (it is not saved explicitely in dynesty, so you'll need to compute logprior yourself)

[epaillas]

Hi, thanks for the reply. According to https://dynesty.readthedocs.io/en/stable/quickstart.html, the dictionary containing the full set of quantities from the sampling results includes:

• logz: the cumulative evidence at each iteration (sample)
• logzerr: the estimated error (standard deviation) on logz

which should correspond to the log_evidence and log_evidence_err columns in my files. I was wondering if this would have to be included in the determination of the log posterior. If it's just an overall normalization factor, I guess it shouldn't impact the MAP, so I'll go ahead and try to compute the log posterior from the likelihood and prior.