These functions compute different types of importance weights based on Jeffreys's priors used in arima_pi.
approx_joint_jeffreys(psi, xreg = NULL, p, q, n)approx_marginal_jeffreys(psi, p, q)
exact_joint_jeffreys(psi, xreg = NULL, p, q, n)
exact_marginal_jeffreys(psi, p, q, n)
vector containing the ar and ma parameters (in that order).
matrix or data frame containing the exogenous variables (not including the intercept which is always included for non-differenced series)
number of ar parameters
number of ma parameters
length of the time series
arima_pi.