'Test the nyq keyword.'

def test_nyq(self):

    nyquist = 1000
    width = 40.0
    relative_width = (width / nyquist)
    (ntaps, beta) = kaiserord(120, relative_width)
    taps = firwin(ntaps, cutoff=[300, 700], window=('kaiser', beta), pass_zero=False, scale=False, nyq=nyquist)
    assert_array_almost_equal(taps[:(ntaps // 2)], taps[ntaps:((ntaps - (ntaps // 2)) - 1):(-1)])
    freq_samples = np.array([0.0, 200, (300 - (width / 2)), (300 + (width / 2)), 500, (700 - (width / 2)), (700 + (width / 2)), 800, 1000])
    (freqs, response) = freqz(taps, worN=((np.pi * freq_samples) / nyquist))
    assert_array_almost_equal(np.abs(response), [0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 0.0, 0.0, 0.0], decimal=5)
