Fig. 9

QSAR-prediction- and PD-classification results for SARS-CoV-2 main protease. Each column corresponds to an upper plot and a lower plot for one of the MMP-sets \({\mathcal {M}}_{\text {inter}}\), \({\mathcal {M}}_{\text {test}}\) or \({\mathcal {M}}_{\text {cores}}\). The x-axis of each upper plot indicates the PD-classification accuracy on the full MMP-set; the x-axis of each lower plot indicates the PD-classification accuracy on a restricted MMP-set only consisting of MMP predicted to be ACs by the respective method. The y-axis of each plot shows the QSAR-prediction performance on the molecular test set \({\mathcal {D}}_{\text {test}}\). The total length of each error bar equals twice the standard deviation of the performance metrics measured over all \(mk = 3*2 = 6\) hyperparameter-optimised models. The accuracy of the PD-classification task for predicted ACs is lacking for the ECFP + kNN technique on \({\mathcal {M}}_{\text {test}}\) and \({\mathcal {M}}_{\text {cores}}\) since this method produced only negative AC-predictions for all trials on this data set. For each plot, the lower right corner corresponds to strong performance at both prediction tasks