save the metrics (precision / recall)

yolov5/utils/metrics.py

@@ -333,6 +333,8 @@ def plot_pr_curve(px, py, ap, save_dir=Path('pr_curve.png'), names=()):
     ax.set_ylim(0, 1)
     ax.legend(bbox_to_anchor=(1.04, 1), loc='upper left')
     ax.set_title('Precision-Recall Curve')
+    metrics_dir = save_dir.parent / 'class_metrics.npy'
+    np.save(metrics_dir, py)
     fig.savefig(save_dir, dpi=250)
     plt.close(fig)