“…These procedures can be distinguished from each other either based on single wavelength selection or wavelength interval selection. Typical single wavelength selection methods include forward selection, 13 backward elimination, 14 stepwise selection, 15 uninformative variable elimination (UVE), 16 Monte Carlo-based UVE (MC-UVE), 17 successive projection algorithm (SPA), 18 iterative predictor weighting (IPW), 19 competitive adaptive reweighted sampling (CARS), 20,21 random frog (RF), 22 recursive weighted partial least squares (rPLS), 23 iteratively retaining informative variables (IRIV), 24 variable combination population analysis (VCPA), 25 variable iterative space shrinkage approach (VISSA), 26 bootstrapping so shrinkage (BOSS), 27 latent projective graph (LPG), 28 methods based on optimization algorithms, such as genetic algorithm (GA), 29,30 particle swarm optimization (PSO), 31 and ant colony optimization (ACO), 32 and methods based on regularization, such as least absolute shrinkage and selection operator (LASSO), 33 elastic net (EN) 34 and sampling error prole analysis-LASSO (SEPA-LASSO). 35 Due to the fact that the absorption band of a functional group corresponds to a relatively short wavelength band in the spectrum, it makes more sense to nd the most useful spectral band interval instead of a single spectral point and it is also easier to obtain a stable model and explain the model.…”