deviance {NMF} | R Documentation |
Distances and Objective Functions
Description
The NMF package defines methods for the generic
deviance
from the package stats
, to compute
approximation errors between NMF models and matrices,
using a variety of objective functions.
nmfDistance
returns a function that computes the
distance between an NMF model and a compatible matrix.
Usage
deviance(object, ...)
## S4 method for signature 'NMF'
deviance(object, y,
method = c("", "KL", "euclidean"), ...)
nmfDistance(method = c("", "KL", "euclidean"))
## S4 method for signature 'NMFfit'
deviance(object, y, method, ...)
## S4 method for signature 'NMFStrategy'
deviance(object, x, y, ...)
Arguments
y |
a matrix compatible with the NMF model
|
method |
a character string or a function with
signature |
... |
extra parameters passed to the objective function. |
x |
an NMF model that estimates |
object |
an object for which the deviance is desired. |
Value
deviance
returns a nonnegative numerical value
nmfDistance
returns a function with least two
arguments: an NMF model and a matrix.
Methods
- deviance
signature(object = "NMF")
: Computes the distance between a matrix and the estimate of anNMF
model.- deviance
signature(object = "NMFfit")
: Returns the deviance of a fitted NMF model.This method returns the final residual value if the target matrix
y
is not supplied, or the approximation error between the fitted NMF model stored inobject
andy
. In this case, the computation is performed using the objective functionmethod
if not missing, or the objective of the algorithm that fitted the model (stored in slot'distance'
).If not computed by the NMF algorithm itself, the value is automatically computed at the end of the fitting process by the function
nmf
, using the objective function associated with the NMF algorithm, so that it should always be available.- deviance
signature(object = "NMFfitX")
: Returns the deviance achieved by the best fit object, i.e. the lowest deviance achieved across all NMF runs.- deviance
signature(object = "NMFStrategy")
: Computes the value of the objective function between the estimatex
and the targety
.
See Also
Other stats: deviance,NMF-method
,
hasTrack
, residuals
,
residuals<-
, trackError