activations.py 文件源码

def derivative(self, input=None):
        """Backward propagation.

        Returns
        -------
        float32 
            The derivative of SymmetricElliot function.
        """
        last_forward = 1 + np.abs(input * self.steepness) if input else self.last_forward
        return self.steepness / np.power(last_forward, 2)


# symmetric-elliot-end
# softplus-start