Create design matrix of switching regression model
# S3 method for heckit5rob
model.matrix(object, part = "outcome", ...)object of class heckit5rob
character string indicating which matrix to extract: "outcome" for the outcome equations, "selection" for the selection equation.
currently not used
If argument part is "outcome", the list containing design matrices of the outcome equations is returned.
design matrix for the first regime
design matrix for the second regime