I am a new stan user and trying to find the posterior of Jeffreys’ prior.

This is my model.

data {

int<lower=0> n; // obs in group x

real x[n];

}

parameters {

real muX;

real<lower=0> sigmaX;

}

model {

x ~ normal(muX, sigmaX);

increment_log_prob(-log(sigmaX));

}

generated quantities {

real postPred;

postPred <- normal_rng(muX, sigmaX);

}

I followed “https://stats.stackexchange.com/questions/156721/define-own-noninformative-prior-in-stan”.

My data also include 0.

How can I add the other parameters in this model?