ChemoSpec (version 3.0-1)

robPCA: Robust PCA of a Spectra Object

Description

A wrapper which carries out robust PCA analysis on a "Spectra" object. The data are row- and column-centered, and the user can select various options for scaling.

Usage

robPCA(spectra, choice = "noscale")

Arguments

spectra

An object of S3 class "Spectra"

choice

A character vector describing the type of scaling to be carried out. One of c("noscale", "mad").

Value

• An object of classes "conPCA" and "princomp" (see q2rPCA). It includes a list element called $method, a character string describing the pre-processing carried out and the type of PCA performed (it appears on plots which you might make).

References

https://github.com/bryanhanson/ChemoSpec K. Varmuza and P. Filzmoser Introduction to Multivariate Statistical Analysis in Chemometrics, CRC Press, 2009.

See Also

See PCAgrid on which this function is based. For the classical version, see classPCA. For displaying the results, plotScree, plotScores, plotLoadings, plotScores3D

Examples

data(SrE.IR)
results <- robPCA(SrE.IR, choice = "mad")
myt <- expression(bolditalic(Serenoa)~bolditalic(repens)~bold(IR~Spectra))
plotScores(SrE.IR, main = myt,
	results, pcs = c(1,2), ellipse = "rob", tol = 0.05)