SIMCA OPLS-DA plot get high positive R2 value, but Q2 is negative, how to fix the problem?

01 July 2021 0 2K Report

Currently, I'm working on the analysis of mass NMR spectrum of my samples in SIMPCA for PCA and OPLS-DA test. However, I'm getting negative of Q2, even increase and decrease the number of components, yet all the values remain negative, what can I do?

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