How to use the amodem.dsp.Demux function in amodem

def test_demux():
    freqs = np.array([1e3, 2e3])
    omegas = 2 * np.pi * freqs / config.Fs
    carriers = [dsp.exp_iwt(2*np.pi*f/config.Fs, config.Nsym) for f in freqs]
    syms = [3, 2j]
    sig = np.dot(syms, carriers)
    res = dsp.Demux(sampling.Sampler(sig.real), omegas, config.Nsym)
    res = np.array(list(res))
    assert np.max(np.abs(res - syms)) < 1e-12

def symbols_stream(signal):
        sampler = sampling.Sampler(signal)
        return dsp.Demux(sampler=sampler, omegas=[omega], Nsym=config.Nsym)
    r = recv.Receiver(config, pylab=common.Dummy())

def run(self, sampler, gain, output):
        log.debug('Receiving')
        symbols = dsp.Demux(sampler, omegas=self.omegas, Nsym=self.Nsym)
        self._prefix(symbols, gain=gain)

        filt = self._train(sampler, order=10, lookahead=10)
        sampler.equalizer = lambda x: list(filt(x))

        bitstream = self._demodulate(sampler, symbols)
        bitstream = itertools.chain.from_iterable(bitstream)

        for frame in framing.decode_frames(bitstream):
            output.write(frame)
            self.output_size += len(frame)

def frame_iter(config, src, frame_length):
    frame_size = frame_length * config.Nsym * config.sample_size
    omegas = 2 * np.pi * np.array(config.frequencies) / config.Fs

    while True:
        data = src.read(frame_size)
        if len(data) < frame_size:
            return
        data = common.loads(data)
        frame = data - np.mean(data)

        sampler = sampling.Sampler(frame)
        symbols = dsp.Demux(sampler, omegas, config.Nsym)

        symbols = np.array(list(symbols))
        coeffs = np.mean(np.abs(symbols) ** 2, axis=0) ** 0.5

        peak = np.max(np.abs(frame))
        total = np.sqrt(np.dot(frame, frame) / (0.5 * len(frame)))
        yield coeffs, peak, total