NMFStrategy-class: Virtual Interface for NMF Algorithms

In NMF: Algorithms and Framework for Nonnegative Matrix Factorization (NMF)

Virtual Interface for NMF Algorithms

Description

This class partially implements the generic interface defined for general algorithms defined in the NMF package (see algorithmic-NMF).

is.mixed tells if an NMF algorithm works on mixed-sign data.

Usage

  ## S4 method for signature 'NMFStrategy'
show(object)

  ## S4 method for signature 'NMFStrategy'
objective(object)

  ## S4 replacement method for signature 'NMFStrategy,character'
objective(object)<-value

  ## S4 replacement method for signature 'NMFStrategy,function'
objective(object)<-value

  is.mixed(object)

Arguments

object	Any R object
value	replacement value

Slots

objective

the objective function associated with the algorithm (Frobenius, Kullback-Leibler, etc...). It is either an access key of a registered objective function or a function definition. In the latter case, the given function must have the following signature (x="NMF", y="matrix") and return a nonnegative real value.

model

a character string giving either the (sub)class name of the NMF-class instance used and returned by the strategy, or a function name.

mixed

a logical that indicates if the algorithm works on mixed-sign data.

Methods

canFit

signature(x = "NMFStrategy", y = "character"): Tells if an NMF algorithm can fit a given class of NMF models

canFit

signature(x = "NMFStrategy", y = "NMF"): Tells if an NMF algorithm can fit the same class of models as y

deviance

signature(object = "NMFStrategy"): Computes the value of the objective function between the estimate x and the target y.

modelname

signature(object = "NMFStrategy"): Returns the model(s) that an NMF algorithm can fit.

NMFStrategy

signature(name = "NMFStrategy", method = "missing"): Creates an NMFStrategy based on a template object (Constructor-Copy), in particular it uses the same name.

objective

signature(object = "NMFStrategy"): Gets the objective function associated with an NMF algorithm.

It is used in deviance to compute the objective value for an NMF model with respect to a given target matrix.

objective

signature(object = "NMFStrategy"): Gets the objective function associated with an NMF algorithm.

It is used in deviance to compute the objective value for an NMF model with respect to a given target matrix.

objective<-

signature(object = "NMFStrategy", value = "character"): Sets the objective function associated with an NMF algorithm, with a character string that must be a registered objective function.

objective<-

signature(object = "NMFStrategy", value = "character"): Sets the objective function associated with an NMF algorithm, with a character string that must be a registered objective function.

objective<-

signature(object = "NMFStrategy", value = "function"): Sets the objective function associated with an NMF algorithm, with a function that computes the approximation error between an NMF model and a target matrix.

objective<-

signature(object = "NMFStrategy", value = "function"): Sets the objective function associated with an NMF algorithm, with a function that computes the approximation error between an NMF model and a target matrix.

run

signature(object = "NMFStrategy", y = "matrix", x = "NMFfit"): Pure virtual method defined for all NMF algorithms to ensure that a method run is defined by sub-classes of NMFStrategy.

It throws an error if called directly.

run

signature(object = "NMFStrategy", y = "matrix", x = "NMF"): Method to run an NMF algorithm directly starting from a given NMF model.

NMF documentation built on Sept. 11, 2024, 8:34 p.m.