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Convert transmittance into absorptance.

Source: R/spct-conversion-qty-unit.R
Afr2T.Rd

Function that converts transmittance (fraction) into absorptance (fraction). If reflectance (fraction) is available, it allows conversions between internal and total absorptance.

Usage

Afr2T(x, action, byref, clean, ...)

# Default S3 method
Afr2T(x, action = NULL, byref = FALSE, clean = FALSE, ...)

# S3 method for class 'numeric'
Afr2T(x, action = NULL, byref = FALSE, clean = FALSE, Rfr = NA_real_, ...)

# S3 method for class 'filter_spct'
Afr2T(x, action = "add", byref = FALSE, clean = FALSE, ...)

# S3 method for class 'object_spct'
Afr2T(x, action = "add", byref = FALSE, clean = FALSE, ...)

# S3 method for class 'filter_mspct'
Afr2T(
  x,
  action = "add",
  byref = FALSE,
  clean = FALSE,
  ...,
  .parallel = FALSE,
  .paropts = NULL
)

# S3 method for class 'object_mspct'
Afr2T(
  x,
  action = "add",
  byref = FALSE,
  clean = FALSE,
  ...,
  .parallel = FALSE,
  .paropts = NULL
)

Arguments

x

an R object

action

character Allowed values "replace" and "add"

byref

logical indicating if new object will be created by reference or by copy of x

clean

logical replace off-boundary values before conversion

...

not used in current version

Rfr

numeric vector. Spectral reflectance o reflectance factor. Set to zero if x is internal reflectance,

.parallel

if TRUE, apply function in parallel, using parallel backend provided by foreach

.paropts

a list of additional options passed into the foreach function when parallel computation is enabled. This is important if (for example) your code relies on external data or packages: use the .export and .packages arguments to supply them so that all cluster nodes have the correct environment set up for computing.

Value

A copy of x with a column Tfr added and other columns possibly deleted except for w.length. If action = "replace", in all cases, the additional columns are removed, even if no column needs to be added.

Methods (by class)

  • Afr2T(default): Default method for generic function

  • Afr2T(numeric): Default method for generic function

  • Afr2T(filter_spct): Method for filter spectra

  • Afr2T(object_spct): Method for object spectra

  • Afr2T(filter_mspct): Method for collections of filter spectra

  • Afr2T(object_mspct): Method for collections of object spectra

See also

Other quantity conversion functions: A2T(), T2A(), T2Afr(), any2T(), as_quantum(), e2q(), e2qmol_multipliers(), e2quantum_multipliers(), q2e()

Examples

T2Afr(Ler_leaf.spct)
#> Object: object_spct [2,401 x 4]
#> Wavelength range 250-850 nm, step 0.25 nm 
#> Label: Ler_06_black.spct 
#> Measured on 2017-07-03 13:17:09.548817 UTC 
#> Variables:
#>  w.length: Wavelength [nm]
#>  Tfr: Total spectral transmittance [/1]
#>  Rfr: Total spectral reflectance [/1]
#>  Afr: Spectral absorptance [/1] 
#> --
#> # A tibble: 2,401 × 4
#>    w.length   Tfr    Rfr   Afr
#>       <dbl> <dbl>  <dbl> <dbl>
#>  1     250      0 0.0467 0.953
#>  2     250.     0 0.0467 0.953
#>  3     250.     0 0.0467 0.953
#>  4     251.     0 0.0467 0.953
#>  5     251      0 0.0467 0.953
#>  6     251.     0 0.0467 0.953
#>  7     252.     0 0.0467 0.953
#>  8     252.     0 0.0467 0.953
#>  9     252      0 0.0467 0.953
#> 10     252.     0 0.0467 0.953
#> # ℹ 2,391 more rows