R: Cross-Validation of Classical PCA Results for a Spectra...

cv_pcaSpectra {ChemoSpec} | R Documentation

## Cross-Validation of Classical PCA Results for a Spectra Object

### Description

This function carries out classical PCA on the data in a `Spectra` object using a cross-validation method. A simple re-write of Peter Filzmoser's `pcaCV` method with some small plotting changes.

### Usage

    cv_pcaSpectra(spectra, pcs, choice = "noscale", repl = 50, segments = 4,
      segment.type = c("random", "consecutive", "interleaved"), length.seg,
      trace = FALSE, ...)

### Arguments

`spectra` | An object of S3 class `Spectra`.
`pcs` | As per `pcaCV` where it is called amax; an integer giving the number of PC scores to include.
`choice` | A character string indicating the choice of scaling. One of `c("noscale"`, `"autoscale"`, `"Pareto")`.
`repl` | As per `pcaCV`; the number of replicates to perform.
`segments` | As per `pcaCV`.
`segment.type` | As per `pcaCV`.
`length.seg` | As per `pcaCV`.
`trace` | As per `pcaCV`.
`...` | Parameters to be passed to the plotting routines.

### Value

A list as described in `pcaCV`, so the result must be assigned or it will appear at the console. Side effect is a plot.

### Author(s)

Bryan A. Hanson, DePauw University. Derived from `pcaCV`.

### References

K. Varmuza and P. Filzmoser Introduction to Multivariate Statistical Analysis in Chemometrics, CRC Press, 2009.

https://github.com/bryanhanson/ChemoSpec

### See Also

`pcaCV` for the underlying function.

### Examples

    data(SrE.IR)
    pca <- cv_pcaSpectra(SrE.IR, pcs = 5)

[Package ChemoSpec version 4.4.97 Index]