r"""
        :math:Add formula

def dre_dc(self, pars):
        r"""
        :math:Add formula
        """
        self._set_parameters(pars)
        # term 1
        num1a = np.log(self.w * self.tau) * self.otc * np.sin(self.ang)
        num1b = self.otc * np.cos(self.ang) * np.pi / 2.0
        term1 = (num1a + num1b) / self.denom

        # term 2
        num2 = self.otc * np.sin(self.c / np.pi) * 2
        denom2 = self.denom ** 2
        term2 = num2 / denom2

        # term 3
        num3a = 2 * np.log(self.w * self.tau) * self.otc * np.cos(self.ang)
        num3b = 2 * ((self.w * self.tau) ** 2) * np.pi / 2.0 * np.sin(self.ang)
        num3c = 2 * np.log(self.w * self.tau) * self.otc2
        term3 = num3a - num3b + num3c

        result = self.sigmai * self.m * (term1 + term2 * term3)

        return result