poissonScaling {tofsims} | R Documentation

## generic method for "poissonScaling"

### Description

Possion scaling for data matrices.

### Usage

    poissonScaling(object, offset = 1, ...)

    ## S4 method for signature 'MassSpectra'
    poissonScaling(object, offset = 1, ...)

### Arguments

`object` | object of class MassSpectra
`offset` | numeric value for poisson scaling
`...` | further args

### Details

Possion scaling is proposed as the method of choice for ToF-SIMS data see Keenan and Kotula 2004. This implementation was done according to a description in `Multivariate Analysis of SIMS spectra in ToF-SIMS: Materials Analysis by Mass Spectrometry, Vickerman and Briggs 2013` and the `eigenvector wiki`. The offset is described in the `eigenvector wiki`.

### Value

object of class MassSpectra with poission scaled mass spectra in slot nz

object of class MassSpectra

### Author(s)

Lorenz Gerber lorenz.gerber@slu.se

### Examples

    ## poisson scaling of MassSpectra objects
    testImage <- MassImage('dummy')
    testImage <- poissonScaling(testImage)
    ## Not run:
    # poission scaling on real data
    library(tofsimsData)
    data(tofsimsData)
    par(mfcol=c(2,2))
    plot(testImage,type='l')
    image(testImage)
    testImage <- poissonScaling(testImage)
    plot(testImage,type='l')
    image(testImage)

    ## End(Not run)

[Package tofsims version 1.22.0 Index]