iir_theory.py 文件源码

def tf_partialfraction(self, frequencies=None):
        """
        Returns the transfer function just before the partial fraction
        expansion for frequencies.

        Parameters
        ----------
        sys: (poles, zeros, k)
        dt:  sampling time
        continuous: if True, returns the transfer function in continuous
                    time domain, if False converts to discrete one
        method: method for scipy.signal.cont2discrete
        alpha:  alpha for above method (see scipy documentation)

        Returns
        -------
        np.array(..., dtype=np.complex)
        """
        # this code is more or less a direct copy of get_coeff()
        if frequencies is None:
            frequencies = self.frequencies
        frequencies = np.asarray(frequencies, dtype=np.complex128)
        r, p, c = self.rp_continuous
        h = freqs_rp(r, p, c, frequencies*2*np.pi)
        return h * self.tf_inputfilter(frequencies=frequencies)