FocalLoss() and obj loss speed and stability update

utils/torch_utils.py

@@ -88,7 +88,7 @@ def model_info(model, verbose=False):
                   (i, name, p.requires_grad, p.numel(), list(p.shape), p.mean(), p.std()))
     print('Model Summary: %g layers, %g parameters, %g gradients' % (len(list(model.parameters())), n_p, n_g))
 
-    # Report FLOPS
+    # FLOPS report
     # from thop import profile
     # macs, params = profile(model, inputs=(torch.zeros(1, 3, 608, 608),))
     # print('%.3f FLOPS' % (macs / 1E9 * 2))