updater.py 文件源码

def _get_loss_gen(self):
        batchsize = self.y_fake.data.shape[0]
        L_mce = F.softmax_cross_entropy(self.pred_label_map, self.ground_truth, normalize=False)
        L_bce = F.softmax_cross_entropy(self.y_fake, Variable(self.xp.ones(batchsize, dtype=self.xp.int32), volatile=not self.gen.train))
        loss = L_mce + self.L_bce_weight * L_bce

        # log report
        label_true = chainer.cuda.to_cpu(self.ground_truth.data)
        label_pred = chainer.cuda.to_cpu(self.pred_label_map.data).argmax(axis=1)
        logs = []
        for i in six.moves.range(batchsize):
            acc, acc_cls, iu, fwavacc = utils.label_accuracy_score(
                label_true[i], label_pred[i], self.n_class)
            logs.append((acc, acc_cls, iu, fwavacc))
        log = np.array(logs).mean(axis=0)
        values = {
            'loss': loss,
            'accuracy': log[0],
            'accuracy_cls': log[1],
            'iu': log[2],
            'fwavacc': log[3],
        }
        chainer.report(values, self.gen)

        return loss