Fig. 4.

The ROC and Precision-Recall curve for the three methods. A logistic model can be considered as a classifier if we set a threshold to the Phred scores. The predicted condition of a base is positive/negative if its Phred score is larger/smaller than the threshold. The true condition of a base is obtained from the mapping of reads to the reference. Consequently, bases will be divided into four categories: true positives, false positive, true negatives, and false negatives. a The ROC curve on the test set by the three methods: the backward deletion with either AIC or BIC, and the L ₁ regularization. b The corresponding precision-recall curve