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Fraction of spectral irradiance in the PAR window.

Source: R/par.R
par_fraction.Rd

Returns the ratio of band-integrated irradiance over 400–700 nm to the total integrated irradiance across the full wavelength range supplied. Useful for characterising how spectrally narrowed a light field has become (e.g. at depth, where red wavelengths are preferentially removed).

Usage

par_fraction(irradiance, ...)

# S3 method for class 'numeric'
par_fraction(irradiance, lambda, binwidth = NULL, ...)

# S3 method for class 'lux_spectrum'
par_fraction(irradiance, ...)

Arguments

irradiance

Spectral irradiance (any consistent energy unit per nm), or a lux_spectrum object.

...

Ignored.

lambda

Wavelength vector in nm.

binwidth

Bin width in nm. Inferred from lambda if NULL.

Value

Numeric scalar in (0, 1].

Examples

sp <- solar_irradiance("clear_noon")
par_fraction(sp$irradiance, sp$wavelength)
#> [1] 0.7742921