A wrapper which carries out classical PCA analysis on a
Spectra object. The user can select various options for
scaling. There is no normalization by rows - do this manually using
normSpectra. There is an option to control centering, but
this is mainly for compatibility with the
series of functions. Centering the data should always be done in PCA and it
is the default here.
An object of S3 class
A character string indicating the choice of scaling. One of
Logical: whether or not to center the data. Always center the data unless you know it to be already centered.
The scale choice
autoscale scales the columns by their standard
Pareto scales by the square root of the standard
An object of class
prcomp, modified to include a list
$method, a character string describing the
pre-processing carried out and the type of PCA performed (it appears on
plots which you might make).
Bryan A. Hanson, DePauw University.
K. Varmuza and P. Filzmoser Introduction to Multivariate Statistical Analysis in Chemometrics, CRC Press, 2009.
prcomp for the underlying function,
r_pcaSpectra for analogous robust PCA calculations.
For displaying the results,
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