Derived quantities of the asymmetric Skellam family from a fitted model

Returns mu, sigma, sigma^2, theta1 and theta2, each as a draws x observations matrix, from a brmsfit fitted with skellam2(). The quantities are computed in R with brms::get_dpar(), because the Stan program generated by brms cannot report them from a generated quantities block. The section "Derived quantities" in skellam2() gives the reason.

Usage

skellam2_dpars(fit, newdata = NULL)

Arguments

fit

A brmsfit fitted with family = skellam2().

newdata

Optional new data, passed to brms::prepare_predictions().

Value

A named list of draws x observations matrices: mu, sigma, sigmasq, theta1, theta2.

See also

skellam2() for the family and the algebra these quantities are derived from.