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Editing: _max_len_seq.cpython-311.pyc
� d�c� � � � d Z ddlZddlmZ dgZi ddg�ddg�ddg�d dg�d d g�d d g�d g d ��dd g�dd g�ddg�dg d��dg d��dg d��ddg�dg d��ddg�ddg�g d �dgd gd gdgg d �d gg d!�g d"�d#gd$gg d%�d&gg d'�d(��Zd*d)�ZdS )+zTools for MLS generation� N� )�_max_len_seq_inner� max_len_seq� � � � � � � )r r r � � � � )r r r � )r r r � )r r r � � )r r r � � )r r r � � )� � r r )� � � )� r r r � )� � r r! )� � r )r r r r r r r r r r! r r# r" � c �� � t j � � j dk r t j n t j }|��| t vrrt j t t � � � � � � � }t d|� � � �d|� � � �d�� � �t j t | |� � }n�t j t j ||� � � � ddd� }t j |dk � � s#t j || k � � s |j dk rt d � � �t j |� � }d | z dz }|�|}n$t |� � }|dk rt d � � �|�"t j | t j d � � � }n9t j |t$ d � � � � t j � � }|j dk s |j | k rt d� � �t j |dk � � rt d� � �t j |t j d � � � }t/ ||| ||� � }||fS )a} 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, 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: https://web.archive.org/web/20181001062252/http://www.newwaveinstruments.com/resources/articles/m_sequence_linear_feedback_shift_register_lfsr.htm .. versionadded:: 0.15.0 Examples -------- MLS uses binary convention: >>> from scipy.signal import max_len_seq >>> max_len_seq(4)[0] array([1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 0, 0], dtype=int8) MLS has a white spectrum (except for DC): >>> import numpy as np >>> import matplotlib.pyplot as plt >>> from numpy.fft import fft, ifft, fftshift, fftfreq >>> seq = max_len_seq(6)[0]*2-1 # +1 and -1 >>> spec = fft(seq) >>> N = len(seq) >>> plt.plot(fftshift(fftfreq(N)), fftshift(np.abs(spec)), '.-') >>> plt.margins(0.1, 0.1) >>> plt.grid(True) >>> plt.show() Circular autocorrelation of MLS is an impulse: >>> acorrcirc = ifft(spec * np.conj(spec)).real >>> plt.figure() >>> plt.plot(np.arange(-N/2+1, N/2+1), fftshift(acorrcirc), '.-') >>> plt.margins(0.1, 0.1) >>> plt.grid(True) >>> plt.show() Linear autocorrelation of MLS is approximately an impulse: >>> acorr = np.correlate(seq, seq, 'full') >>> plt.figure() >>> plt.plot(np.arange(-N+1, N), acorr, '.-') >>> plt.margins(0.1, 0.1) >>> plt.grid(True) >>> plt.show() r Nznbits must be between z and z if taps is None���r r zEtaps must be non-empty with values between zero and nbits (inclusive)r z)length must be greater than or equal to 0�c)�dtype�orderz'state must be a 1-D array of size nbitszstate must not be all zeros)�np�intp�itemsize�int32�int64� _mls_taps�array�list�keys� ValueError�min�max�unique�any�size�int�ones�int8�bool�astype�ndim�all�emptyr )�nbits�state�length�taps� taps_dtype� known_taps�n_max�seqs �;/usr/lib/python3/dist-packages/scipy/signal/_max_len_seq.pyr r s6 � �f �W�Y�Y� /�1� 4� 4����"�(�J� �|� � � !� !���$�y�~�~�'7�'7�"8�"8�9�9�J� �*� *��� 0� 0� 0� 0�*�.�.�2B�2B�2B�2B� D� E� E� E��x� �%�(�*�5�5����y���$� �3�3�4�4�T�T�r�T�:�� �6�$��(� � � ;�r�v�d�U�l� 3� 3� ;�t�y�1�}�}� � :� ;� ;� ;��x��~�~�� ��X��N�E� �~�����V���� �A�:�:� � H�I�I� I� �}����R�W�C�8�8�8��� ���d�#�6�6�6�=�=�b�g�F�F�� �z�Q���%�*��-�-��B�C�C�C� �v�e�q�j��� 8��6�7�7�7� �(�6���� 4� 4� 4�C� �t�U�E�6�3� ?� ?�E� ��:�� )NNN)�__doc__�numpyr* r �__all__r/ r � rJ rI �<module>rO s� �� � � � � � � 2� 2� 2� 2� 2� 2� �/�� )�Q��� )�Q��� )�Q��� )�Q��� )�Q��� )�Q��� )�Q� � � � )� ��� )��!�� )� �1�#� )�')�;�;�;� )�8:�K�K�K� )� ���� )� �2�$� )�(*�K�K�K� )�9;�b�T� )� �"�� )� (�<�<�b�T��t�"����<�<�<�b�T�|�|�|� � � �B�4�b�T�{�{�{���<�<�<� )� )� )� �u� u� u� u� u� urJ
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