Fig. 4

Receiver operating characteristic (ROC) curves of PPCNM. a, Support vector machine, SVM b, Logistic regression, LR. c, Linear discrimination analysis, LDA. Acc accuracy, Sen sensitivity, Spe specificity, P the P value of AUC comparison between SVM vs. LR and SVM vs. LDA calculated by pROC package in R. The ROC showed the AUC of the best combination after cross-validation, therefore, it lacked the ‘arc’ shape