... structure, and their molecular environment.In complex systems such as ce lls, the main absorptionsarise from N–H, C ¼O, C–H and P¼O bonds from the proteins, lipids, and nucleic acids present in the ... samples o f the cell line A and a test set c omposed of 30spectra of cell line A and cell line B. The trainin g set was the only one used for model calculations (PCA, geneticalgorithm and LDA).Data ... intraclass variance, and constructs a linearcombination of the variables to discriminate between the classes. The rule i s constructed with training set of samples, and further tested with the test set....