viz.py 文件源码

def phase_string(sig):
    """Take the angle and create a string as \pi if close to some \pi values"""
    if isinstance(sig, np.ndarray):
        sig = sig.ravel()[0]
    if isinstance(sig, np.complex):
        angle = np.angle(sig)
    else:
        angle = sig

    fractions = [Fraction(i, 12) for i in np.arange(-12, 12 + 1)]
    pi_multiples = np.array([np.pi * frac_to_float(f) for f in fractions])
    strings = [frac_to_str(f) for f in fractions]

    if np.min(np.abs(angle - pi_multiples)) < 1e-3:
        return strings[np.argmin(np.abs(angle - pi_multiples))]
    else:
        return '%.2f' % angle