Converts absorbance spectra to transmittance spectra or vice versa

ir_to_transmittance converts absorbance spectra to transmittance spectra. ir_to_absorbance converts transmittance spectra to absorbance spectra. Note that neither function checks whether the input spectra are absorbance or transmittance spectra.

Usage

ir_to_transmittance(x)

ir_to_absorbance(x)

Source

(Stuart 2004) .

Arguments

x

An object of class ir.

Value

x with y values fore each spectrum as transmittance values (in case of ir_to_transmittance) or absorbance values (in case of ir_to_absorbance).

References

Stuart BH (2004). Infrared Spectroscopy: Fundamentals and Applications: Stuart/Infrared Spectroscopy: Fundamentals and Applications, Analytical Techniques in the Sciences. John Wiley \& Sons, Ltd, Chichester, UK. ISBN 978-0-470-01114-0 978-0-470-85428-0, doi:10.1002/0470011149 .

Examples

# convert from absorbance to transmittance
x1 <-
    ir_sample_data %>%
    ir_to_transmittance()

# convert from transmittance to absorbance
x2 <-
    x1 %>%
    ir::ir_to_absorbance()

vapply(
  seq_along(x2$spectra),
  FUN = function(i) all.equal(x2$spectra[[i]], ir::ir_sample_data$spectra[[i]]),
  FUN.VALUE = logical(1L)
) %>%
  all()
#> [1] TRUE