def max_len_seq(nbits, state=None, length=None, taps=None):
    """
    Maximum length sequence (MLS) generator.

    Parameters
    ----------
    nbits : int
        Number of bits to use. Length of the resulting sequence will
        be ``(2**nbits) - 1``. Note that generating long sequences
        (e.g., greater than ``nbits == 16``) can take a long time.
    state : array_like, optional
        If array, must be of length ``nbits``, and will be cast to binary
        (bool) representation. If None, a seed of ones will be used,
        producing a repeatable representation. If ``state`` is all
        zeros, an error is raised as this is invalid. Default: None.
    length : int | None, optional
        Number of samples to compute. If None, the entire length
        ``(2**nbits) - 1`` is computed.
    taps : array_like, optional
        Polynomial taps to use (e.g., ``[7, 6, 1]`` for an 8-bit sequence).
        If None, taps will be automatically selected (for up to
        ``nbits == 32``).

    Returns
    -------
    seq : array
        Resulting MLS sequence of 0's and 1's.
    state : array
        The final state of the shift register.

    Notes
    -----
    The algorithm for MLS generation is generically described in:

        https://en.wikipedia.org/wiki/Maximum_length_sequence

    The default values for taps are specifically taken from the first
    option listed for each value of ``nbits`` in:

        http://www.newwaveinstruments.com/resources/articles/
            m_sequence_linear_feedback_shift_register_lfsr.htm

    .. versionadded:: 0.15.0
    """
    if taps is None:
        if nbits not in _mls_taps:
            known_taps = np.array(list(_mls_taps.keys()))
            raise ValueError('nbits must be between %s and %s if taps is None'
                             % (known_taps.min(), known_taps.max()))
        taps = np.array(_mls_taps[nbits], np.intp)
    else:
        taps = np.unique(np.array(taps, np.intp))[::-1]
        if np.any(taps < 0) or np.any(taps > nbits) or taps.size < 1:
            raise ValueError('taps must be non-empty with values between '
                             'zero and nbits (inclusive)')
        taps = np.ascontiguousarray(taps)  # needed for Cython
    n_max = (2**nbits) - 1
    if length is None:
        length = n_max
    else:
        length = int(length)
        if length < 0:
            raise ValueError('length must be greater than or equal to 0')
    # We use int8 instead of bool here because numpy arrays of bools
    # don't seem to work nicely with Cython
    if state is None:
        state = np.ones(nbits, dtype=np.int8, order='c')
    else:
        # makes a copy if need be, ensuring it's 0's and 1's
        state = np.array(state, dtype=bool, order='c').astype(np.int8)
    if state.ndim != 1 or state.size != nbits:
        raise ValueError('state must be a 1-dimensional array of size nbits')
    if np.all(state == 0):
        raise ValueError('state must not be all zeros')

    seq = np.empty(length, dtype=np.int8, order='c')
    state = _max_len_seq_inner(taps, state, nbits, length, seq)
    return seq, state
dataset/ETHPy150Open scipy/scipy/scipy/signal/_max_len_seq.py/max_len_seq/original