Cast to Sparse
Arguments passed to other methods
NULL or a character vector giving the row names for
the data; missing values are not allowed
TRUE, setting row names and
converting column names (to syntactic names: see
make.names) is optional. Note that all of R's
as.data.frame() methods use
optional only for column names treatment, basically with the
data.frame(*, check.names = !optional).
See also the
make.names argument of the
logical: should the character vector be converted to a factor?
as.data.frame.Matrix: A data frame representation of the S4 Matrix