def _calc_fourier_spectrum(self, fa_length=None):
        """Compute the Fourier Amplitude Spectrum of the time series."""

        if fa_length is None:
            # Use the next power of 2 for the length
            n = 1
            while n < self.accels.size:
                n <<= 1
        else:
            n = fa_length

        self._fourier_amps = np.fft.rfft(self._accels, n)

        freq_step = 1. / (2 * self._time_step * (n / 2))
        self._freqs = freq_step * np.arange(1 + n / 2)
def _calc_fourier_spectrum ( self , fa_length = None ) : if fa_length is None : n = 1 while n < self . accels . size : n <<= 1 else : n = fa_length self . _fourier_amps = np . fft . rfft ( self . _accels , n ) freq_step = 1. / ( 2 * self . _time_step * ( n / 2 ) ) self . _freqs = freq_step * np . arange ( 1 + n / 2 )
Compute the Fourier Amplitude Spectrum of the time series.