fit | R Documentation |

The functions `fit`

and `minfit`

are S4
genetics that extract the best model object and the best
fit object respectively, from a collection of models or
from a wrapper object.

`fit<-`

sets the fitted model in a fit object. It is
meant to be called only when developing new NMF
algorithms, e.g. to update the value of the model stored
in the starting point.

```
fit(object, ...)
fit(object)<-value
minfit(object, ...)
```

`object` |
an object fitted by some algorithm, e.g. as
returned by the function |

`value` |
replacement value |

`...` |
extra arguments to allow extension |

A fit object differs from a model object in that it contains data about the fit, such as the initial RNG settings, the CPU time used, etc..., while a model object only contains the actual modelling data such as regression coefficients, loadings, etc...

That best model is generally defined as the one that achieves the maximum/minimum some quantitative measure, amongst all models in a collection.

In the case of NMF models, the best model is the one that achieves the best approximation error, according to the objective function associated with the algorithm that performed the fit(s).

- fit
`signature(object = "NMFfit")`

: Returns the NMF model object stored in slot`'fit'`

.- fit
`signature(object = "NMFfitX")`

: Returns the model object that achieves the lowest residual approximation error across all the runs.It is a pure virtual method defined to ensure

`fit`

is defined for sub-classes of`NMFfitX`

, which throws an error if called.- fit
`signature(object = "NMFfitX1")`

: Returns the model object associated with the best fit, amongst all the runs performed when fitting`object`

.Since

`NMFfitX1`

objects only hold the best fit, this method simply returns the NMF model fitted by`object`

– that is stored in slot ‘fit’.- fit
`signature(object = "NMFfitXn")`

: Returns the best NMF fit object amongst all the fits stored in`object`

, i.e. the fit that achieves the lowest estimation residuals.- fit<-
`signature(object = "NMFfit", value = "NMF")`

: Updates the NMF model object stored in slot`'fit'`

with a new value.- minfit
`signature(object = "NMFfit")`

: Returns the object its self, since there it is the result of a single NMF run.- minfit
`signature(object = "NMFfitX")`

: Returns the fit object that achieves the lowest residual approximation error across all the runs.It is a pure virtual method defined to ensure

`minfit`

is defined for sub-classes of`NMFfitX`

, which throws an error if called.- minfit
`signature(object = "NMFfitX1")`

: Returns the fit object associated with the best fit, amongst all the runs performed when fitting`object`

.Since

`NMFfitX1`

objects only hold the best fit, this method simply returns`object`

coerced into an`NMFfit`

object.- minfit
`signature(object = "NMFfitXn")`

: Returns the best NMF model in the list, i.e. the run that achieved the lower estimation residuals.The model is selected based on its

`deviance`

value.

NMF documentation built on March 31, 2023, 6:55 p.m.

Embedding an R snippet on your website

Add the following code to your website.

For more information on customizing the embed code, read Embedding Snippets.