R: Photon or energy ratio

waveband_ratio {photobiology} | R Documentation

## Photon or energy ratio

### Description

This function gives the (energy or photon) irradiance ratio between two given wavebands of a radiation spectrum.

### Usage

    waveband_ratio(w.length, s.irrad, w.band.num = NULL, w.band.denom = NULL,
      unit.out.num = NULL, unit.out.denom = unit.out.num, unit.in = "energy",
      check.spectrum = TRUE, use.cached.mult = FALSE,
      use.hinges = getOption("photobiology.use.hinges", default = NULL))

### Arguments

`w.length` | numeric Vector of wavelengths (nm)
`s.irrad` | numeric vector of spectral (energy or photon) irradiances (W m-2 nm-1) or (mol s-1 m-2 nm-1).
`w.band.num` | waveband object used to compute the numerator of the ratio.
`w.band.denom` | waveband object used to compute the denominator of the ratio.
`unit.out.num` | character Allowed values "energy", and "photon", or its alias "quantum".
`unit.out.denom` | character Allowed values "energy", and "photon", or its alias "quantum".
`unit.in` | character Allowed values "energy", and "photon", or its alias "quantum".
`check.spectrum` | logical Flag indicating whether to sanity check input data, default is TRUE.
`use.cached.mult` | logical Flag indicating whether multiplier values should be cached between calls.
`use.hinges` | logical Flag indicating whether to insert "hinges" into the spectral data before integration so as to reduce interpolation errors at the boundaries of the wavebands.

### Value

a single numeric value giving the ratio

### Note

The default for both `w.band` parameters is a waveband covering the whole range of `w.length`. From version 9.19 onwards use of this default does not trigger a warning, but instead is used silently.

### Examples

    # photon:photon ratio
    with(sun.data,
         waveband_ratio(w.length, s.e.irrad,
                        new_waveband(400,500),
                        new_waveband(400,700), "photon"))
    # energy:energy ratio
    with(sun.data,
         waveband_ratio(w.length, s.e.irrad,
                        new_waveband(400,500),
                        new_waveband(400,700), "energy"))
    # energy:photon ratio
    with(sun.data,
         waveband_ratio(w.length, s.e.irrad,
                        new_waveband(400,700),
                        new_waveband(400,700),
                        "energy", "photon"))
    # photon:photon ratio waveband : whole spectrum
    with(sun.data,
         waveband_ratio(w.length, s.e.irrad,
                        new_waveband(400,500),
                        unit.out.num="photon"))
    # photon:photon ratio of whole spectrum should be equal to 1.0
    with(sun.data,
         waveband_ratio(w.length, s.e.irrad,
         unit.out.num="photon"))

[Package photobiology version 0.9.21 Index]