def result(self, psd_state):
        """Return freqs and averaged PSD for given center frequency"""
        freq_array = numpy.fft.fftshift(psd_state['freq_array'])
        pwr_array = numpy.fft.fftshift(psd_state['pwr_array'])

        if self._crop_factor:
            crop_bins_half = round((self._crop_factor * self._bins) / 2)
            freq_array = freq_array[crop_bins_half:-crop_bins_half]
            pwr_array = pwr_array[crop_bins_half:-crop_bins_half]

        if psd_state['repeats'] > 1:
            pwr_array = pwr_array / psd_state['repeats']

        if self._log_scale:
            pwr_array = 10 * numpy.log10(pwr_array)

        return (freq_array, pwr_array)