downdate_beta_negative_binomial

function downdate_beta_negative_binomial(x:Integer, k:Integer, α':Real, β':Real) -> (Real, Real)

Downdate the parameters of a Beta distribution with a Negative Binomial likelihood.

  • x: The variate.
  • k: Number of successes.
  • α': Posterior first shape.
  • β': Posterior second shape.

Returns: the prior hyperparameters α and β.