Fig. 2. Perturbation accuracy of the test sets using PCA-LDA (green), SVM (red), and CNN (blue) via three separate perturbation methods.

a Effect of applying wavenumber shift perturbation (cm⁻¹). b Effect of applying the objective perturbation, given as a percentage of the total estimated objective contribution that was added. c Effect of applying the response perturbation (%), given as the percentage change induced across the data. Mean accuracies are reported +/− 1 SD. Black dotted lines correspond to the maximum response perturbation observed between the three instruments (detailed in SI5).