def power_spectrum(self, input_filepath):
effect_args = ['<STR_LIT>', '<STR_LIT:1>', '<STR_LIT>', '<STR_LIT>']<EOL>_, _, stat_output = self.build(<EOL>input_filepath, None, extra_args=effect_args, return_output=True<EOL>)<EOL>power_spectrum = []<EOL>lines = stat_output.split('<STR_LIT:\n>')<EOL>for line in lines:<EOL><INDENT>split_line = line.split()<EOL>if len(split_line) != <NUM_LIT:2>:<EOL><INDENT>continue<EOL><DEDENT>freq, amp = split_line<EOL>power_spectrum.append([float(freq), float(amp)])<EOL><DEDENT>return power_spectrum<EOL>
Calculates the power spectrum (4096 point DFT). This method
        internally invokes the stat command with the -freq option.

        Note: The file is downmixed to mono prior to computation.

        Parameters
        ----------
        input_filepath : str
            Path to input file to compute stats on.

        Returns
        -------
        power_spectrum : list
            List of frequency (Hz), amplitude pairs.

        See Also
        --------
        stat, stats, sox.file_info