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 (NMF) `dim`(x) S4 (NMFfitXn) `dim`(x)

- x
- an object with suitable
`basis`

and`coef`

methods, such as an object that inherit from`NMF-class`

. - ...
- extra arguments to allow extension.

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.

The NMF package does not implement specific functions
`nrow`

and `ncol`

, but rather the S4 method
`dim`

for objects of class `NMF-class`

.
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.

- dim
`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). - dim
`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. - nbasis
`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.

- nbasis
`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.