G. Robertsson, Contributions to the problem of approximation of non-linear data with linear PLS in an absorption spectroscopic context, CHEM INTELL, 47(1), 1999, pp. 99-106
This paper presents a simple way to extend the regressor variables in PLS.
The method is particularly suited for non-linear absorption spectra or any
other measurements of soft saturation type. Absorption below a certain limi
t is described as linear and above this limit as non-linear. The extension
of the regressor variables are the squared absorbances above the linear ran
ge. The proposed method is compared with both PLS and with PLS where regres
sors are extended with the squared X-block. The proposed method gives more
parsimonious models and better predictions than existing methods for the da
ta set used in this study, UV-VIS with absorbances in the region 0-2.8. (C)
1999 Elsevier Science B.V. All rights reserved.