codekingpro/portable-devtools
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S4 j5 r\ " S5 SS j5 r\ " S5 SS j5 rg)z+5Discrete Fourier Transforms - _helper.py6 7� )�arange�asarray�empty�integer�roll)�array_function_dispatch�8set_module)�fftshift� ifftshift�fftfreq�rfftfreqNc � � U 4$ �N� )�x�axess �WD:\code\apps\devtools\python\user_packages\Python313\site-packages\numpy/fft/_helper.py�_fftshift_dispatcherr s � �
�4�K� z numpy.fft)�modulec �V � [ U 5 n Uc= [ [ U R 5 5 nU R Vs/ s H o"S- PM nnOI[ U[ 5 ( a U R U S- nO!U Vs/ s H o@R U S- PM nn[ XU5 $ s snf s snf )a� 9Shift the zero-frequency component to the center of the spectrum.10 11This function swaps half-spaces for all axes listed (defaults to all).12Note that ``y[0]`` is the Nyquist component only if ``len(x)`` is even.13 14Parameters15----------16x : array_like17 Input array.18axes : int or shape tuple, optional19 Axes over which to shift. Default is None, which shifts all axes.20 21Returns22-------23y : ndarray24 The shifted array.25 26See Also27--------28ifftshift : The inverse of `fftshift`.29 30Examples31--------32>>> import numpy as np33>>> freqs = np.fft.fftfreq(10, 0.1)34>>> freqs35array([ 0., 1., 2., ..., -3., -2., -1.])36>>> np.fft.fftshift(freqs)37array([-5., -4., -3., -2., -1., 0., 1., 2., 3., 4.])38 39Shift the zero-frequency component only along the second axis:40 41>>> freqs = np.fft.fftfreq(9, d=1./9).reshape(3, 3)42>>> freqs43array([[ 0., 1., 2.],44 [ 3., 4., -4.],45 [-3., -2., -1.]])46>>> np.fft.fftshift(freqs, axes=(1,))47array([[ 2., 0., 1.],48 [-4., 3., 4.],49 [-1., -3., -2.]])50 51� �r �tuple�range�ndim�shape�52isinstance�
integer_typesr �r r �dim�shift�axs r r53 r54 s� � �\ ��55�A� �|��U�1�6�6�]�#��%&�W�W�-�W�c���W��-�� �D�-� (� (�����
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.�� 2s �B!�8B&c �\ � [ U 5 n Uc> [ [ U R 5 5 nU R Vs/ s H o"S- * PM56 nnOK[ U[ 5 ( a U R U S- * nO"U Vs/ s H o@R U S- * PM nn[ XU5 $ s snf s snf )a� 57The inverse of `fftshift`. Although identical for even-length `x`, the58functions differ by one sample for odd-length `x`.59 60Parameters61----------62x : array_like63 Input array.64axes : int or shape tuple, optional65 Axes over which to calculate. Defaults to None, which shifts all axes.66 67Returns68-------69y : ndarray70 The shifted array.71 72See Also73--------74fftshift : Shift zero-frequency component to the center of the spectrum.75 76Examples77--------78>>> import numpy as np79>>> freqs = np.fft.fftfreq(9, d=1./9).reshape(3, 3)80>>> freqs81array([[ 0., 1., 2.],82 [ 3., 4., -4.],83 [-3., -2., -1.]])84>>> np.fft.ifftshift(np.fft.fftshift(freqs))85array([[ 0., 1., 2.],86 [ 3., 4., -4.],87 [-3., -2., -1.]])88 89r r r s r r r M s� � �H ��90�A� �|��U�1�6�6�]�#��()���0���!�8����0�� �D�-� (� (��'�'�$�-�1�$�%��/3�4�t��7�7�2�;�!�#�$�t��4� ��$� � ��
1�� 5s �B$�: B)c �� � [ U [ 5 ( d [ S5 eSX- - n[ U [ US9nU S-91 S- S- n[ SU[ US9nXdSU& [ U S- * S[ US9nXtUS& XC- $ ) a� 92Return the Discrete Fourier Transform sample frequencies.93 94The returned float array `f` contains the frequency bin centers in cycles95per unit of the sample spacing (with zero at the start). For instance, if96the sample spacing is in seconds, then the frequency unit is cycles/second.97 98Given a window length `n` and a sample spacing `d`::99 100 f = [0, 1, ..., n/2-1, -n/2, ..., -1] / (d*n) if n is even101 f = [0, 1, ..., (n-1)/2, -(n-1)/2, ..., -1] / (d*n) if n is odd102 103Parameters104----------105n : int106 Window length.107d : scalar, optional108 Sample spacing (inverse of the sampling rate). Defaults to 1.109device : str, optional110 The device on which to place the created array. Default: ``None``.111 For Array-API interoperability only, so must be ``"cpu"`` if passed.112 113 .. versionadded:: 2.0.0114 115Returns116-------117f : ndarray118 Array of length `n` containing the sample frequencies.119 120Examples121--------122>>> import numpy as np123>>> signal = np.array([-2, 8, 6, 4, 1, 0, 3, 5], dtype=float)124>>> fourier = np.fft.fft(signal)125>>> n = signal.size126>>> timestep = 0.1127>>> freq = np.fft.fftfreq(n, d=timestep)128>>> freq129array([ 0. , 1.25, 2.5 , ..., -3.75, -2.5 , -1.25])130 131�n should be an integer� �?)�device� r r ��dtyper( N)r r �132ValueErrorr �intr )�n�dr( �val�results�N�p1�p2s r r r } s� � �V �a� � '� '��1�2�2�133
���-�C��A�s�6�*�G� 134�Q��1� �q��A� ��1�C�� /�B��B�Q�K� �!�q�&� �1�C�� 7�B��A�B�K� �=�r c � � [ U [ 5 ( d [ S5 eSX- - nU S- S- n[ SU[ US9nXS- $ )a� 135Return the Discrete Fourier Transform sample frequencies136(for usage with rfft, irfft).137 138The returned float array `f` contains the frequency bin centers in cycles139per unit of the sample spacing (with zero at the start). For instance, if140the sample spacing is in seconds, then the frequency unit is cycles/second.141 142Given a window length `n` and a sample spacing `d`::143 144 f = [0, 1, ..., n/2-1, n/2] / (d*n) if n is even145 f = [0, 1, ..., (n-1)/2-1, (n-1)/2] / (d*n) if n is odd146 147Unlike `fftfreq` (but like `scipy.fftpack.rfftfreq`)148the Nyquist frequency component is considered to be positive.149 150Parameters151----------152n : int153 Window length.154d : scalar, optional155 Sample spacing (inverse of the sampling rate). Defaults to 1.156device : str, optional157 The device on which to place the created array. Default: ``None``.158 For Array-API interoperability only, so must be ``"cpu"`` if passed.159 160 .. versionadded:: 2.0.0161 162Returns163-------164f : ndarray165 Array of length ``n//2 + 1`` containing the sample frequencies.166 167Examples168--------169>>> import numpy as np170>>> signal = np.array([-2, 8, 6, 4, 1, 0, 3, 5, -3, 4], dtype=float)171>>> fourier = np.fft.rfft(signal)172>>> n = signal.size173>>> sample_rate = 100174>>> freq = np.fft.fftfreq(n, d=1./sample_rate)175>>> freq176array([ 0., 10., 20., ..., -30., -20., -10.])177>>> freq = np.fft.rfftfreq(n, d=1./sample_rate)178>>> freq179array([ 0., 10., 20., 30., 40., 50.])180 181r& r' r r) r r* )r r r, r r- )r. r/ r( r0 r2 r1 s r r
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