Compute the pseudo-acceleration spectral response of an oscillator
        with a specific frequency and damping.

        Parameters
        ----------
        osc_freq : float
            Frequency of the oscillator (Hz).
        osc_damping : float
            Fractional damping of the oscillator (dec). For example, 0.05 for a
            damping ratio of 5%.
        tf : array_like, optional
            Transfer function to be applied to motion prior calculation of the
            oscillator response.

        Returns
        -------
        spec_accels : :class:`numpy.ndarray`
            Peak pseudo-spectral acceleration of the oscillator

def calc_osc_accels(self, osc_freqs, osc_damping=0.05, tf=None):
        """Compute the pseudo-acceleration spectral response of an oscillator
        with a specific frequency and damping.

        Parameters
        ----------
        osc_freq : float
            Frequency of the oscillator (Hz).
        osc_damping : float
            Fractional damping of the oscillator (dec). For example, 0.05 for a
            damping ratio of 5%.
        tf : array_like, optional
            Transfer function to be applied to motion prior calculation of the
            oscillator response.

        Returns
        -------
        spec_accels : :class:`numpy.ndarray`
            Peak pseudo-spectral acceleration of the oscillator
        """
        if tf is None:
            tf = np.ones_like(self.freqs)
        else:
            tf = np.asarray(tf).astype(complex)

        resp = np.array([
            self.calc_peak(tf * self._calc_sdof_tf(of, osc_damping))
            for of in osc_freqs
        ])
        return resp