modelfit-class {IPPD} | R Documentation

## "Modelfit"

### Description

Object returned from a call to fitModelParameters.

### Slots

model

  The chosen model, either `"Gaussian"` or `"EMG"`.

fitting

  The mode of fitting which generated the object. Either `"most_intense"` or `"model"`.

alphafunction

  A function of m/z that computes an estimate for the `EMG` parameter `alpha`. See fitModelParameters for more detailed information on this parameter.

sigmafunction

  A function of m/z that computes an estimate for the `EMG` parameter `sigma`. See fitModelParameters for more detailed information on this parameter.

mufunction

  A function of m/z that computes an estimate for the `EMG` parameter `mu`. See fitModelParameters for more detailed information on this parameter.

peakfitresults

  A `matrix` of five columns if `model = "Gaussian"` and of six columns if `model = "EMG"`, respectively. The matrix contains basic information on the extracted peaks and the corresponding parameters. The first column contains the number of (mz, intensity)-pairs used for fitting, the second column contains the residual sums of squares of the model fit, the middle columns the parameter estimates and the last column the m/z position.

bestpeak

  A `list` containing detailed information on the 'best' peak, where 'best' is equivalent to 'minimum residual sums of squares' after fitting. Mainly used indirectly by calling the function `visualize`.

### Methods

show

  Use `show(object)` for brief information about the object.

visualize

  A function to display graphically the result of parameter estimation. One can either visualize a single peak (`slot(object, "bestpeak")`) or the fit of the linear models postulated for the parameters `alpha`, `sigma` and `mu`. The function `visualize` is called with the following set of parameters.

  `object`

    An object of class `modelfit`.

  `type`

    A `character` specifying the object to be visualized. If `type = "peak"`, the fit of a single peak stored in `object@bestpeak` is displayed. If `type = "model"`, one obtains scatterplots of the form `parameter` vs. `mz` for each parameter in `parameters`, s. below.

  `parameters`

    Needed if and only if `type = "model"` in order to choose the y-variable of the scatterplot. Several parameters may be specified at a time, in which case one obtains a multi-panel plot.

  `modelfit`

    A `logical` indicating whether the estimated regression functions should be added to the scatterplots (if `type = "model"`).

[Package IPPD version 1.30.0 Index]