residuals: Residuals in NMF Models

Description

The package NMF defines methods for the function residuals that returns the final residuals of an NMF fit or the track of the residuals along the fit process, computed according to the objective function associated with the algorithm that fitted the model.

residuals<- sets the value of the last residuals, or, optionally, of the complete residual track.

Tells if an NMFfit object contains a recorded residual track.

trackError adds a residual value to the track of residuals.

Usage

residuals(object, ...)
  # S4 method for NMFfit
residuals(object, track = FALSE,
    niter = NULL, ...)
  residuals(object, ...)<-value
  # S4 method for NMFfit
residuals(object, ..., niter = NULL,
    track = FALSE)<-value
  hasTrack(object, niter = NULL)
  trackError(object, value, niter, force = FALSE)

Value

residuals returns a single numeric value if

track=FALSE or a numeric vector containing the residual values at some iterations. The names correspond to the iterations at which the residuals were computed.

Arguments

object: an NMFfit object as fitted by function nmf, in single run mode.
...: extra parameters (not used)
track: a logical that indicates if the complete track of residuals should be returned (if it has been computed during the fit), or only the last value.
niter: specifies the iteration number for which one wants to get/set/test a residual value. This argument is used only if not NULL
value: residual value
force: logical that indicates if the value should be added to the track even if there already is a value for this iteration number or if the iteration does not conform to the tracking interval nmf.getOption('track.interval').

Methods

residuals: signature(object = "NMFfit"): Returns the residuals -- track -- between the target matrix and the NMF fit object.
residuals: signature(object = "NMFfitX"): Returns the residuals achieved by the best fit object, i.e. the lowest residual approximation error achieved across all NMF runs.

Details

When called with track=TRUE, the whole residuals track is returned, if available. Note that method nmf does not compute the residuals track, unless explicitly required.