Measuring and comparing the resolution performance and the extent of rotation ambiguities of some bilinear modeling methods

Bilinear models are often used in the analysis of datasets from spectroscopy and chromatography. Whenever bilinear soft modeling approaches are applied, rotation ambiguities are ubiquitously present and they should be considered. In this work, results obtained by the application of different methods like independent component analysis (ICA), principal component analysis (PCA), and minimum volume simplex analysis (MVSA) are compared with those obtained by multivariate curve resolution (MCR). In order to do this comparison, mutual information (MI), Amari index (AI), and lack-of-fit (lof) parameters are used for the evaluation of the different methods, and the corresponding areas or regions of feasible solutions (AFS) and their boundaries are investigated in each case. The results obtained by the MCR-BANDS method in the calculation of the extension of rotation ambiguities are discussed and compared with those obtained by the FAC-PACK method, which has been recently proposed for the estimation of the whole range of feasible solutions. (C) 2015 Elsevier B.V. All rights reserved.