sum_spectra: Add two spectra

Description

The wavelength vectors of the two spectra are merged, and the missing spectral values are calculated by interpolation. After this, the two spectral values at each wavelength are added. This is 'parallel' operation between two spectra.

Usage

sum_spectra(w.length1, w.length2 = NULL, s.irrad1, s.irrad2, trim = "union", na.rm = FALSE)

Arguments

w.length1

numeric array of wavelength (nm)

w.length2

numeric array of wavelength (nm)

s.irrad1

a numeric array of spectral values

s.irrad2

a numeric array of spectral values

trim

a character string with value "union" or "intersection"

na.rm

a logical value, if TRUE, not the default, NAs in the input are replaced with zeros

Value

a dataframe with two numeric variables a dataframe with two numeric variables

Details

If trim=="union" spectral values are calculated for the whole range of wavelengths covered by at least one of the input spectra, and missing values are set in each input spectrum to zero before addition. If trim=="intersection" then the range of wavelengths covered by both input spectra is returned, and the non-overlaping regions discarded. If w.length2==NULL, it is assumed that both spectra are measured at the same wavelengths, and a simple addition is used, ensuring fast calculation.

Examples

Run this code


head(sun.data)
twice.sun.data <- with(sun.data, sum_spectra(w.length, w.length, s.e.irrad, s.e.irrad))
head(twice.sun.data)
tail(twice.sun.data)