ChemoSpec, spectral data sets are stored in an S3 class called
Spectra, which contains a variety of information in addition to the
Spectra objects are created by
The structure of a
Spectra object is a list of 9
elements and an attribute as follows:
$freq (numeric) A common frequency (or wavelength) axis for all the spectra.
$data (numeric) The intensities for the spectra. A matrix of dimension no. samples x no. frequency points.
$names (character) The sample names for the spectra; length must be no. samples.
$groups (factor) The group classification of the samples; length must be no. samples.
$colors (character) The colors for each sample; length must be no. samples. Groups and colors correspond.
$sym (integer) As for
colors, but symbols for plotting (if b/w is desired).
$alt.sym (character) Lower-case letters as alternate symbols for plotting.
$unit (character) Two entries, the first giving the x axis unit, the second the y axis unit.
$desc (character) A character string describing the data set. This appears on plots and therefore should probably be kept to 40 characters or less.
attribute: character with value "Spectra" The S3 class designation.