MCR-ALS GUI 2.0: new features and applications

Abstract

An updated version of the graphical user-friendly interface related to the Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) algorithm is presented. This GUI works under MATLAB® environment and includes recently published advances of this algorithm linked to the implementation of additional constraints, such as kinetic hard-modeling and correlation (calibration), as well as constraints linked to model structure for multiset and multi-way data analysis, such as the possibility to use fully or partially multilinear models (trilinear or quadrilinear) to describe the data set. In addition, a step has been included to allow the preliminary subspace maximum likelihood projection to decrease noise propagation effects in case of large non-homoscedastic uncertainties, and the possibility of direct selection of number of components and of initial estimates. Finally, a number of options to present and handle the output information have been added, such as the display of data fitting evolution, improvement in the display of loadings profiles in different modes for multi-way data, refolding MCR scores into 2D distribution maps for hyperspectral images and the internal connection to the MCR-Bands GUI, previously designed for the assessment of the extent and location of ambiguities in the MCR resolved profiles. Different examples of use of this updated interface are given in this work.