Stan code for inferring probability of m-face dice.

m_dice.stan

data
{
  int <lower=0> m; // The number of dice faces 
  int <lower=0> x[m]; // The numbers of events. x[i] indicates the number of occurence of i-th face.
}

parameters
{
  simplex[m] theta; // Occurence probabilities.
}

model
{
  x ~ multinomial(theta);
}