In ChemoSpec, spectral data sets are stored in an S3 class called
Spectra, which contains a variety of information in addition to the
spectra themselves. Spectra objects are created by
files2SpectraObject or matrix2SpectraObject.
The structure of a Spectra object is a list of 9
elements and an attribute as follows:
| element | type | description |
| $freq | num | A common frequency (or wavelength) axis for all the spectra. |
| $data | num | The intensities for the spectra. A matrix of dimension |
| no. samples x no. frequency points. | ||
| $names | chr | 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 | chr | 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 | chr | Lower-case letters as alternate symbols for plotting. |
| $unit | chr | Two entries, the first giving the x axis unit, the second the y axis unit. |
| $desc | chr | A character string describing the data set. This appears on plots and therefore |
| should probably be kept to 40 characters or less. | ||
| - attr | chr "Spectra" | The S3 class designation. |
sumSpectra to summarize a Spectra object.
sumGroups to summarize group membership of a Spectra
object. chkSpectra to verify the integrity of a
Spectra object. colorSymbol for a discussion of color
options. Finally, additional documentation at https://bryanhanson.github.io/ChemoSpec/