# glp.model.matrix: Utility function for constructing generalized polynomial smooths

## Description

Produce model matrices for a generalized polynomial smooth from the
model matrices for the marginal bases of the smooth.

## Arguments

X

a list of model matrices for the marginal bases of a smooth

## Value

A model matrix for a generalized polynomial smooth.

## Details

This function computes a generalized polynomial where the
orders of each term entering the polynomial may vary.

## References

Hall, P. and J.S. Racine (forthcoming), “Cross-Validated
Generalized Local Polynomial Regression,” Journal of Econometrics.

## Examples

# NOT RUN {
X <- list(matrix(1:4,2,2),matrix(5:10,2,3))
glp.model.matrix(X)
# }