title: [Classification of pharmaceutical tablet with canonical variates analysis method in spectra analysis].
abstract: A novel classifier was constructed in the present paper by combination of an improved canonical variates analysis (ICVA) with Fish linear discriminant analysis (LDA). The resulting discrimination model based on this proposed approach (ICVA-LDA) was divided into two parts: the inner part that estimated the robust weight vector of canonical variates by linear partial least square algorithm and the outer part that built the LDA discrimination model by making use of the extracted canonical variates. The method utilized partial least squares regression as an engine for solving an eigenvector problem involving singular covariance matrices and the canonical variates were more relevant for discriminative purposes. Thus, the weight vectors found in the modified CVA method not only possessed the same properties as weight vectors of the standard CVA method, but also forced the discriminative information into the first fewer of canonical variates. The improved discrimination model was more concise and efficient in dealing with the problem of the effect sensitivity and numerous predictor variables with serious multicollinearity in the spectra data. Furthermore, in ICVA-LDA the interpretation could be performed with respect to the original high-dimensional data space. Finally, application to a four-group problem with near-infrared transmittance spectroscopy data consisting of 310 samples and 404 variables of the proposed ICVA-LDA approach was presented with comparison to the LDA combined with principal component analysis (PCA-LDA) and standard CVA-LDA methods. All the three discrimination models were validated using fivefold segmented cross-validation. The result demonstrates that the limitations of LDA were overcome with PLS algorithm and then the classification performance of LDA was improved by ICVA. This proposed approach can also be widely used in other fields for classification and discrimination of small samples and collinear data.
authors.affiliation: Department of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou 310012, China. chengzhong@zust.edu.cn
authors.forename: Zhong
authors.initials: Z
authors.lastname: Cheng
authors.forename: Ai-Shi
authors.initials: AS
authors.lastname: Zhu
mesh_terms: D000704:Analysis of Variance; D016002:Discriminant Analysis; D016014:Linear Models; D004364:Pharmaceutical Preparations / Q000737:chemistry / Q000145:classification*; D025341:Principal Component Analysis; D013055:Spectrophotometry, Infrared / Q000706:statistics & numerical data*; D013607:Tablets
chemical_list: D004364:Pharmaceutical Preparations; D013607:Tablets