Grow a model matrix while at the same time compactly encoding missingness patterns in RHS variables of a model frame.
model_matrix(object, data = environment(object), remove.intercept = TRUE, ...)
ModelMatrixPlus, i.e. model matrix enriched with missing data info
Model formula or terms object (as in `model.matrix`)
data.frame, as in `model.matrix()` but has to have ‘(weights)
’ column
logical
passed to `model.matrix.default` (and further)
Ben B Hansen