Figure 2.

ROC curves for the seven database search methods tested when using the centroid data (A1−A4 of ISB data set). Each search method is abbreviated by its first letter in the figure legend. ROC curves of the first type are displayed in panel A, while the ROC curves of the second type are displayed in panel B. Since the total number of spectra in this subset is about 7000, in panel B, the displayed highest number of false positives, 600, corresponds approximately to E-value 0.1. We did not show ROC curves of the second type to larger FP value because users probably will not be too interested in the large E-value regime.