The methods dim, nrow, ncol and
nbasis return the different dimensions associated
with an NMF model.
dim returns all dimensions in a length-3 integer
vector: the number of row and columns of the estimated
target matrix, as well as the factorization rank (i.e.
the number of basis components).
nrow, ncol and nbasis provide
separate access to each of these dimensions respectively.
nbasis(x, ...) # S4 method for NMF
dim(x)
# S4 method for NMFfitXn
dim(x)
a single integer value or, for dim, a length-3
integer vector, e.g. c(2000, 30, 3) for an
NMF model that fits a 2000 x 30 matrix using 3
basis components.
an object with suitable basis and
coef methods, such as an object that inherit from
NMF.
extra arguments to allow extension.
signature(x = "NMF"): method for NMF
objects for the base generic dim. It
returns all dimensions in a length-3 integer vector: the
number of row and columns of the estimated target matrix,
as well as the factorization rank (i.e. the number of
basis components).
signature(x = "NMFfitXn"): Returns the
dimension common to all fits.
Since all fits have the same dimensions, it returns the
dimension of the first fit. This method returns
NULL if the object is empty.
signature(x = "ANY"): Default method
which returns the number of columns of the basis matrix
extracted from x using a suitable method
basis, or, if the latter is NULL, the value
of attributes 'nbasis'.
For NMF models, this also corresponds to the number of rows in the coefficient matrix.
signature(x = "NMFfitXn"): Returns
the number of basis components common to all fits.
Since all fits have been computed using the same rank, it
returns the factorization rank of the first fit. This
method returns NULL if the object is empty.
The NMF package does not implement specific functions
nrow and ncol, but rather the S4 method
dim for objects of class NMF.
This allows the base methods nrow and
ncol to directly work with such objects, to
get the number of rows and columns of the target matrix
estimated by an NMF model.
The function nbasis is a new S4 generic defined in
the package NMF, that returns the number of basis
components of an object. Its default method should work
for any object, that has a suitable basis method
defined for its class.