ChemoSpec (version 4.4.97)

plotLoadings: Plot PCA Loadings for a Spectra Object

Description

Creates a multi-panel plot of loadings along with a reference spectrum.

Usage

plotLoadings(spectra, pca, loads = c(1), ref = 1, ...)

Arguments

spectra

An object of S3 class Spectra.

pca

An object of class prcomp, modified to include a list element called $method, a character string describing the pre-processing carried out and the type of PCA performed (it appears on the plot). This is automatically provided if ChemoSpec functions c_pcaSpectra or r_pcaSpectra were used to create pca.

loads

An integer vector giving the loadings to plot. More than 3 loadings creates a useless plot using the default graphics window.

ref

An integer specifying the reference spectrum to plot, which appears at the bottom of the plot.

…

Additional parameters to be passed to plotting functions.

Value

None. Side effect is a plot.

References

https://github.com/bryanhanson/ChemoSpec

See Also

See plot2Loadings to plot two loadings against each other, and sPlotSpectra for an alternative approach.

Examples

# NOT RUN {
data(SrE.IR)
pca <- c_pcaSpectra(SrE.IR, choice = "noscale")
myt <- expression(bolditalic(Serenoa)~bolditalic(repens)~bold(IR~Spectra))
plotLoadings(SrE.IR, pca, main = myt,
	 loads = 1:2, ref = 1)

# }