R: Virtual Interface for NMF Algorithms

NMFStrategy-class {NMF} | R Documentation

## 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.

[Package NMF version 0.21.0 Index]