The spectacles package provides the user with S4 classes that have been developped to store and manipulate spectroscopy data.
The Spectra
class is storing the spectra matrix, along with the
wavelengths at which those have been measured, the units in whioch those
wavelengths are expressed, and a unique id for each sample in the
collection.
The SpectraDataFrame
class is extending the Spectra
class by
giving the opportunity to store attribute data along with the spectra - this
is mostly the case when we want to predict physical or chemical properties
from the spectra set.
The SpatialSpectra
and SpatialSpectraDataFrame
classes are
extending the Spectra
and SpectraDataFrame
classes using the
SpatialPoints
class from package sp. This allows to store spatial
information on the dataset: coordinates, coordinate reference system,
bounding box, etc.
Common generic methods implemented for these classes include:
summary
, show
, nrow
, length
, plot
,
[
, [[
, $
.
SpatialPoints
methods from the sp package can be applied to
SpatialSpectra
and SpatialSpectraDataFrame
objects are they
inherit from this class.
Class for spectra collections with associated attributes
wl
object of class "numeric
"; the wavelengths at which the spectra has been measured
nir
object of class "matrix
"; the spectra, with as many columns as wavelengths, and as many rows as samples
id
object of class "data.frame
" with one attribute; the identification strings for each sample in the collection
units
object of class "character
"; units in which the wavelengths are expressed
data
object of class data.frame containing the attribute data
Objects can be created by calls of the form
new("Spectra", ...)
, with the constructor functions like
Spectra(...)
, or with the helper functions such as wl
and
spectra
.
# NOT RUN {
showClass("Spectra")
showClass("SpectraDataFrame")
# }
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