Returns the model matrix for the specified submodel.
# S3 method for lmSubsets
model.matrix(object, size, best = 1, ...)# S3 method for lmSelect
model.matrix(object, best, ...)
"lmSubsets", "lmSelect"---a subset
regression
integer---the submodel size
integer---the submodel position
forwarded to model.frame()
double[,]---the model matrix
lmSubsets() for all-subsets
regression
lmSelect() for best-subset
regression
model.matrix() for the S3
generic