Method grad

code/chapter6.py:222–224

(y_true, y_pred, z, acti_fn)

    @staticmethod
    def grad(y_true, y_pred, z, acti_fn):
        (n, _) = y_true.shape
        return (y_pred - y_true) * acti_fn.grad(z) / n


class CrossEntropy(ObjectiveBase):