ChemoSpec (version 2.0-2)

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")

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).

Rdversion

1.1

References

http://academic.depauw.edu/~hanson/ChemoSpec/ChemoSpec.html 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)