This function calculates innovations in WAR(p) models
getInnovation(quantile, quantile.grid, p)A list with
innovation - The tangent space innovations evaluated over the quantile grid. Fitting a WAR(p) model for \(n\) observations will produce \(n-2p\) innovations.
cov.surf - The covariance surface
A matrix containing all the available quantile functions. Columns represent time indices and rows represent evaluation grid.
A numeric vector, the grid over which quantile functions are evaluated.
A positive integer, the order of the fitted WAR(p) model.
Wasserstein Autoregressive Models for Density Time Series, Chao Zhang, Piotr Kokoszka, Alexander Petersen, 2022