eem_humification_index: Calculate the fluorescence humification index (HIX)
Description
The fluorescence humification index (HIX), which compares two
broad aromatic dominated fluorescence maxima, is calculated at 254 nm
excitation by dividing the sum of fluorescence intensities between emission
435 to 480 nm by the the sum of fluorescence intensities between 300 to 345
nm.
A data frame containing the humification index (HIX) for each eem.
Arguments
eem
An object of class eemlist.
scale
Logical indicating if HIX should be scaled, default is FALSE.
See details for more information.
verbose
Logical determining if additional messages should be printed.
Interpolation
Different excitation and emission wavelengths are often used to measure
EEMs. Hence, it is possible to have mismatchs between measured wavelengths
and wavelengths used to calculate specific metrics. In these
circumstances, EEMs are interpolated using the
interp2 function from the parcma library. A
message warning the user will be prompted if data interpolation is
performed.
References
Ohno, T. (2002). Fluorescence Inner-Filtering Correction for
Determining the Humification Index of Dissolved Organic Matter.
Environmental Science & Technology, 36(4), 742-746.