I am trying to access the content of Stanfit object using summary function given in this post: Accessing the contents of a stanfit object and I am wondering whether I could find the sourse code for the summary function. Currently I found that after applying the summary function, some of the parameters have values in ‘mean’ but NaN in their ‘se_mean’, ‘n_eff’ and ‘Rhat’ and I am wondering whether this might be a problem due to the summary function.

I have four chains with default iterations in Rstan. I have applied the ‘extract’ function to check the draws of parameters, and for some parameters having this issue they all have the same values (all 0s), while for other parameters having this issue they have different numbers (many 0s plus some small numbers like 3e^-300, 7e^-150).

Sure and my model is included in one of my other posts here: Undefined values in generated quantities block. The problem happened for generated quantities like ‘numerator’ and ‘denominator’.