eem_biological_index: Calculate the biological fluorescence index (BIX)
Description
The biological fluorescence index (BIX) is calculated by
dividing the fluorescence at excitation 310 nm and emission at 380 nm (ex =
310, em = 380) by that at excitation 310 nm and emission at 430 nm (ex =
310, em = 430).
Usage
eem_biological_index(eem, verbose = TRUE)
Value
An object of class eemlist.
A data frame containing the biological index (BIX) for each eem.
Arguments
eem
An object of class eemlist.
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
Huguet, A., Vacher, L., Relexans, S., Saubusse, S., Froidefond,
J. M., & Parlanti, E. (2009). Properties of fluorescent dissolved organic
matter in the Gironde Estuary. Organic Geochemistry, 40(6), 706-719.