"modelMatrix" and notably its subclass
"dsparseModelMatrix" are used to encode additional information,
analogously to what the standard R function
“actual” (aka non-virtual) classes. For these,
objects can be created by calls of the form
new("dsparseModelMatrix", x, assign, contrast), where
dgCMatrix classed object.
"modelMatrix" mother class contains
Matrix plus two extra slots,
"integer" vector of length
ncol(.), coding the variables which make up the
matrix columns, see
contrasts, as in
integer vector of length two with the matrix dimensions.
list of length two, the
dimnames(.) of the matrix.
whereas the (current only) actual classes
have an at least an additional (
E.g., "dsparseModelMatrix" has the additional slots
row number and “pointer” integer
vectors, see class
"numeric" vector of non-zero entries.
a (possibly empty)
"dsparseModelMatrix" extends class
"ddenseModelMatrix" extends class
signature(object = "modelMatrix"):
show(.) the matrix, but also the
signature(x = "modelMatrix"): as
...) allowing to pass further arguments for
printing the matrix.
sparse.model.matrix will return a
model.Matrix which is a simple wrapper around the traditional
model.matrix and returns a
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