s_var: Variance of a collection of spectra

In aphalo/photobiology: Photobiological Calculations

Variance of a collection of spectra

Description

A method to compute the variance of values across members of a collections of spectra. Computes the variance at each wavelength across all the spectra in the collection returning a spectral object.

Usage

s_var(x, na.rm, ...)

## Default S3 method:
s_var(x, na.rm = FALSE, ...)

## S3 method for class 'filter_mspct'
s_var(x, na.rm = FALSE, ...)

## S3 method for class 'source_mspct'
s_var(x, na.rm = FALSE, ...)

## S3 method for class 'response_mspct'
s_var(x, na.rm = FALSE, ...)

## S3 method for class 'reflector_mspct'
s_var(x, na.rm = FALSE, ...)

## S3 method for class 'calibration_mspct'
s_var(x, na.rm = FALSE, ...)

## S3 method for class 'cps_mspct'
s_var(x, na.rm = FALSE, ...)

## S3 method for class 'raw_mspct'
s_var(x, na.rm = FALSE, ...)

Arguments

x	An R object. Currently this package defines methods for collections of spectral objects.
na.rm	logical. A value indicating whether NA values should be stripped before the computation proceeds.
...	Further arguments passed to or from other methods.

Details

Variance method for collections of spectra. Computes the variance at each wavelength across all the spectra in the collection.

Value

If x is a collection spectral of objects, such as a "filter_mspct" object, the returned object is of class "generic_spct", containing the variance among the spectra at each wavelength in a column with name ending in ".var".

Methods (by class)

• s_var(default):

• s_var(filter_mspct):

• s_var(source_mspct):

• s_var(response_mspct):

• s_var(reflector_mspct):

• s_var(calibration_mspct):

• s_var(cps_mspct):

• s_var(raw_mspct):

Note

Omission of NAs is done separately at each wavelength. Interpolation is not applied, so all spectra in x must share the same set of wavelengths.

Objects of classes raw_spct and cps_spct can contain data from multiple scans. This functions are implemented for these classes only for the case when all member spectra contain data for a single scan, or spliced into a single column in the case of cps_spct members.

See Also

See cor for details about var(), which is used for the computations.

aphalo/photobiology documentation built on April 1, 2024, 6:48 p.m.