asd

venv/lib/python3.12/site-packages/scipy/fftpack/__init__.py

@@ -0,0 +1,103 @@
+"""
+=========================================================
+Legacy discrete Fourier transforms (:mod:`scipy.fftpack`)
+=========================================================
+
+.. legacy::
+
+   New code should use :mod:`scipy.fft`.
+
+Fast Fourier Transforms (FFTs)
+==============================
+
+.. autosummary::
+   :toctree: generated/
+
+   fft - Fast (discrete) Fourier Transform (FFT)
+   ifft - Inverse FFT
+   fft2 - 2-D FFT
+   ifft2 - 2-D inverse FFT
+   fftn - N-D FFT
+   ifftn - N-D inverse FFT
+   rfft - FFT of strictly real-valued sequence
+   irfft - Inverse of rfft
+   dct - Discrete cosine transform
+   idct - Inverse discrete cosine transform
+   dctn - N-D Discrete cosine transform
+   idctn - N-D Inverse discrete cosine transform
+   dst - Discrete sine transform
+   idst - Inverse discrete sine transform
+   dstn - N-D Discrete sine transform
+   idstn - N-D Inverse discrete sine transform
+
+Differential and pseudo-differential operators
+==============================================
+
+.. autosummary::
+   :toctree: generated/
+
+   diff - Differentiation and integration of periodic sequences
+   tilbert - Tilbert transform:         cs_diff(x,h,h)
+   itilbert - Inverse Tilbert transform: sc_diff(x,h,h)
+   hilbert - Hilbert transform:         cs_diff(x,inf,inf)
+   ihilbert - Inverse Hilbert transform: sc_diff(x,inf,inf)
+   cs_diff - cosh/sinh pseudo-derivative of periodic sequences
+   sc_diff - sinh/cosh pseudo-derivative of periodic sequences
+   ss_diff - sinh/sinh pseudo-derivative of periodic sequences
+   cc_diff - cosh/cosh pseudo-derivative of periodic sequences
+   shift - Shift periodic sequences
+
+Helper functions
+================
+
+.. autosummary::
+   :toctree: generated/
+
+   fftshift - Shift the zero-frequency component to the center of the spectrum
+   ifftshift - The inverse of `fftshift`
+   fftfreq - Return the Discrete Fourier Transform sample frequencies
+   rfftfreq - DFT sample frequencies (for usage with rfft, irfft)
+   next_fast_len - Find the optimal length to zero-pad an FFT for speed
+
+Note that ``fftshift``, ``ifftshift`` and ``fftfreq`` are numpy functions
+exposed by ``fftpack``; importing them from ``numpy`` should be preferred.
+
+Convolutions (:mod:`scipy.fftpack.convolve`)
+============================================
+
+.. module:: scipy.fftpack.convolve
+
+.. autosummary::
+   :toctree: generated/
+
+   convolve
+   convolve_z
+   init_convolution_kernel
+   destroy_convolve_cache
+
+"""
+
+
+__all__ = ['fft','ifft','fftn','ifftn','rfft','irfft',
+           'fft2','ifft2',
+           'diff',
+           'tilbert','itilbert','hilbert','ihilbert',
+           'sc_diff','cs_diff','cc_diff','ss_diff',
+           'shift',
+           'fftfreq', 'rfftfreq',
+           'fftshift', 'ifftshift',
+           'next_fast_len',
+           'dct', 'idct', 'dst', 'idst', 'dctn', 'idctn', 'dstn', 'idstn'
+           ]
+
+from ._basic import *
+from ._pseudo_diffs import *
+from ._helper import *
+from ._realtransforms import *
+
+# Deprecated namespaces, to be removed in v2.0.0
+from . import basic, helper, pseudo_diffs, realtransforms
+
+from scipy._lib._testutils import PytestTester
+test = PytestTester(__name__)
+del PytestTester

venv/lib/python3.12/site-packages/scipy/fftpack/_basic.py

@@ -0,0 +1,428 @@
+"""
+Discrete Fourier Transforms - _basic.py
+"""
+# Created by Pearu Peterson, August,September 2002
+__all__ = ['fft','ifft','fftn','ifftn','rfft','irfft',
+           'fft2','ifft2']
+
+from scipy.fft import _pocketfft
+from ._helper import _good_shape
+
+
+def fft(x, n=None, axis=-1, overwrite_x=False):
+    """
+    Return discrete Fourier transform of real or complex sequence.
+
+    The returned complex array contains ``y(0), y(1),..., y(n-1)``, where
+
+    ``y(j) = (x * exp(-2*pi*sqrt(-1)*j*np.arange(n)/n)).sum()``.
+
+    Parameters
+    ----------
+    x : array_like
+        Array to Fourier transform.
+    n : int, optional
+        Length of the Fourier transform. If ``n < x.shape[axis]``, `x` is
+        truncated. If ``n > x.shape[axis]``, `x` is zero-padded. The
+        default results in ``n = x.shape[axis]``.
+    axis : int, optional
+        Axis along which the fft's are computed; the default is over the
+        last axis (i.e., ``axis=-1``).
+    overwrite_x : bool, optional
+        If True, the contents of `x` can be destroyed; the default is False.
+
+    Returns
+    -------
+    z : complex ndarray
+        with the elements::
+
+            [y(0),y(1),..,y(n/2),y(1-n/2),...,y(-1)]        if n is even
+            [y(0),y(1),..,y((n-1)/2),y(-(n-1)/2),...,y(-1)]  if n is odd
+
+        where::
+
+            y(j) = sum[k=0..n-1] x[k] * exp(-sqrt(-1)*j*k* 2*pi/n), j = 0..n-1
+
+    See Also
+    --------
+    ifft : Inverse FFT
+    rfft : FFT of a real sequence
+
+    Notes
+    -----
+    The packing of the result is "standard": If ``A = fft(a, n)``, then
+    ``A[0]`` contains the zero-frequency term, ``A[1:n/2]`` contains the
+    positive-frequency terms, and ``A[n/2:]`` contains the negative-frequency
+    terms, in order of decreasingly negative frequency. So ,for an 8-point
+    transform, the frequencies of the result are [0, 1, 2, 3, -4, -3, -2, -1].
+    To rearrange the fft output so that the zero-frequency component is
+    centered, like [-4, -3, -2, -1,  0,  1,  2,  3], use `fftshift`.
+
+    Both single and double precision routines are implemented. Half precision
+    inputs will be converted to single precision. Non-floating-point inputs
+    will be converted to double precision. Long-double precision inputs are
+    not supported.
+
+    This function is most efficient when `n` is a power of two, and least
+    efficient when `n` is prime.
+
+    Note that if ``x`` is real-valued, then ``A[j] == A[n-j].conjugate()``.
+    If ``x`` is real-valued and ``n`` is even, then ``A[n/2]`` is real.
+
+    If the data type of `x` is real, a "real FFT" algorithm is automatically
+    used, which roughly halves the computation time. To increase efficiency
+    a little further, use `rfft`, which does the same calculation, but only
+    outputs half of the symmetrical spectrum. If the data is both real and
+    symmetrical, the `dct` can again double the efficiency by generating
+    half of the spectrum from half of the signal.
+
+    Examples
+    --------
+    >>> import numpy as np
+    >>> from scipy.fftpack import fft, ifft
+    >>> x = np.arange(5)
+    >>> np.allclose(fft(ifft(x)), x, atol=1e-15)  # within numerical accuracy.
+    True
+
+    """
+    return _pocketfft.fft(x, n, axis, None, overwrite_x)
+
+
+def ifft(x, n=None, axis=-1, overwrite_x=False):
+    """
+    Return discrete inverse Fourier transform of real or complex sequence.
+
+    The returned complex array contains ``y(0), y(1),..., y(n-1)``, where
+
+    ``y(j) = (x * exp(2*pi*sqrt(-1)*j*np.arange(n)/n)).mean()``.
+
+    Parameters
+    ----------
+    x : array_like
+        Transformed data to invert.
+    n : int, optional
+        Length of the inverse Fourier transform.  If ``n < x.shape[axis]``,
+        `x` is truncated. If ``n > x.shape[axis]``, `x` is zero-padded.
+        The default results in ``n = x.shape[axis]``.
+    axis : int, optional
+        Axis along which the ifft's are computed; the default is over the
+        last axis (i.e., ``axis=-1``).
+    overwrite_x : bool, optional
+        If True, the contents of `x` can be destroyed; the default is False.
+
+    Returns
+    -------
+    ifft : ndarray of floats
+        The inverse discrete Fourier transform.
+
+    See Also
+    --------
+    fft : Forward FFT
+
+    Notes
+    -----
+    Both single and double precision routines are implemented. Half precision
+    inputs will be converted to single precision. Non-floating-point inputs
+    will be converted to double precision. Long-double precision inputs are
+    not supported.
+
+    This function is most efficient when `n` is a power of two, and least
+    efficient when `n` is prime.
+
+    If the data type of `x` is real, a "real IFFT" algorithm is automatically
+    used, which roughly halves the computation time.
+
+    Examples
+    --------
+    >>> from scipy.fftpack import fft, ifft
+    >>> import numpy as np
+    >>> x = np.arange(5)
+    >>> np.allclose(ifft(fft(x)), x, atol=1e-15)  # within numerical accuracy.
+    True
+
+    """
+    return _pocketfft.ifft(x, n, axis, None, overwrite_x)
+
+
+def rfft(x, n=None, axis=-1, overwrite_x=False):
+    """
+    Discrete Fourier transform of a real sequence.
+
+    Parameters
+    ----------
+    x : array_like, real-valued
+        The data to transform.
+    n : int, optional
+        Defines the length of the Fourier transform. If `n` is not specified
+        (the default) then ``n = x.shape[axis]``. If ``n < x.shape[axis]``,
+        `x` is truncated, if ``n > x.shape[axis]``, `x` is zero-padded.
+    axis : int, optional
+        The axis along which the transform is applied. The default is the
+        last axis.
+    overwrite_x : bool, optional
+        If set to true, the contents of `x` can be overwritten. Default is
+        False.
+
+    Returns
+    -------
+    z : real ndarray
+        The returned real array contains::
+
+          [y(0),Re(y(1)),Im(y(1)),...,Re(y(n/2))]              if n is even
+          [y(0),Re(y(1)),Im(y(1)),...,Re(y(n/2)),Im(y(n/2))]   if n is odd
+
+        where::
+
+          y(j) = sum[k=0..n-1] x[k] * exp(-sqrt(-1)*j*k*2*pi/n)
+          j = 0..n-1
+
+    See Also
+    --------
+    fft, irfft, scipy.fft.rfft
+
+    Notes
+    -----
+    Within numerical accuracy, ``y == rfft(irfft(y))``.
+
+    Both single and double precision routines are implemented. Half precision
+    inputs will be converted to single precision. Non-floating-point inputs
+    will be converted to double precision. Long-double precision inputs are
+    not supported.
+
+    To get an output with a complex datatype, consider using the newer
+    function `scipy.fft.rfft`.
+
+    Examples
+    --------
+    >>> from scipy.fftpack import fft, rfft
+    >>> a = [9, -9, 1, 3]
+    >>> fft(a)
+    array([  4. +0.j,   8.+12.j,  16. +0.j,   8.-12.j])
+    >>> rfft(a)
+    array([  4.,   8.,  12.,  16.])
+
+    """
+    return _pocketfft.rfft_fftpack(x, n, axis, None, overwrite_x)
+
+
+def irfft(x, n=None, axis=-1, overwrite_x=False):
+    """
+    Return inverse discrete Fourier transform of real sequence x.
+
+    The contents of `x` are interpreted as the output of the `rfft`
+    function.
+
+    Parameters
+    ----------
+    x : array_like
+        Transformed data to invert.
+    n : int, optional
+        Length of the inverse Fourier transform.
+        If n < x.shape[axis], x is truncated.
+        If n > x.shape[axis], x is zero-padded.
+        The default results in n = x.shape[axis].
+    axis : int, optional
+        Axis along which the ifft's are computed; the default is over
+        the last axis (i.e., axis=-1).
+    overwrite_x : bool, optional
+        If True, the contents of `x` can be destroyed; the default is False.
+
+    Returns
+    -------
+    irfft : ndarray of floats
+        The inverse discrete Fourier transform.
+
+    See Also
+    --------
+    rfft, ifft, scipy.fft.irfft
+
+    Notes
+    -----
+    The returned real array contains::
+
+        [y(0),y(1),...,y(n-1)]
+
+    where for n is even::
+
+        y(j) = 1/n (sum[k=1..n/2-1] (x[2*k-1]+sqrt(-1)*x[2*k])
+                                     * exp(sqrt(-1)*j*k* 2*pi/n)
+                    + c.c. + x[0] + (-1)**(j) x[n-1])
+
+    and for n is odd::
+
+        y(j) = 1/n (sum[k=1..(n-1)/2] (x[2*k-1]+sqrt(-1)*x[2*k])
+                                     * exp(sqrt(-1)*j*k* 2*pi/n)
+                    + c.c. + x[0])
+
+    c.c. denotes complex conjugate of preceding expression.
+
+    For details on input parameters, see `rfft`.
+
+    To process (conjugate-symmetric) frequency-domain data with a complex
+    datatype, consider using the newer function `scipy.fft.irfft`.
+
+    Examples
+    --------
+    >>> from scipy.fftpack import rfft, irfft
+    >>> a = [1.0, 2.0, 3.0, 4.0, 5.0]
+    >>> irfft(a)
+    array([ 2.6       , -3.16405192,  1.24398433, -1.14955713,  1.46962473])
+    >>> irfft(rfft(a))
+    array([1., 2., 3., 4., 5.])
+
+    """
+    return _pocketfft.irfft_fftpack(x, n, axis, None, overwrite_x)
+
+
+def fftn(x, shape=None, axes=None, overwrite_x=False):
+    """
+    Return multidimensional discrete Fourier transform.
+
+    The returned array contains::
+
+      y[j_1,..,j_d] = sum[k_1=0..n_1-1, ..., k_d=0..n_d-1]
+         x[k_1,..,k_d] * prod[i=1..d] exp(-sqrt(-1)*2*pi/n_i * j_i * k_i)
+
+    where d = len(x.shape) and n = x.shape.
+
+    Parameters
+    ----------
+    x : array_like
+        The (N-D) array to transform.
+    shape : int or array_like of ints or None, optional
+        The shape of the result. If both `shape` and `axes` (see below) are
+        None, `shape` is ``x.shape``; if `shape` is None but `axes` is
+        not None, then `shape` is ``numpy.take(x.shape, axes, axis=0)``.
+        If ``shape[i] > x.shape[i]``, the ith dimension is padded with zeros.
+        If ``shape[i] < x.shape[i]``, the ith dimension is truncated to
+        length ``shape[i]``.
+        If any element of `shape` is -1, the size of the corresponding
+        dimension of `x` is used.
+    axes : int or array_like of ints or None, optional
+        The axes of `x` (`y` if `shape` is not None) along which the
+        transform is applied.
+        The default is over all axes.
+    overwrite_x : bool, optional
+        If True, the contents of `x` can be destroyed. Default is False.
+
+    Returns
+    -------
+    y : complex-valued N-D NumPy array
+        The (N-D) DFT of the input array.
+
+    See Also
+    --------
+    ifftn
+
+    Notes
+    -----
+    If ``x`` is real-valued, then
+    ``y[..., j_i, ...] == y[..., n_i-j_i, ...].conjugate()``.
+
+    Both single and double precision routines are implemented. Half precision
+    inputs will be converted to single precision. Non-floating-point inputs
+    will be converted to double precision. Long-double precision inputs are
+    not supported.
+
+    Examples
+    --------
+    >>> import numpy as np
+    >>> from scipy.fftpack import fftn, ifftn
+    >>> y = (-np.arange(16), 8 - np.arange(16), np.arange(16))
+    >>> np.allclose(y, fftn(ifftn(y)))
+    True
+
+    """
+    shape = _good_shape(x, shape, axes)
+    return _pocketfft.fftn(x, shape, axes, None, overwrite_x)
+
+
+def ifftn(x, shape=None, axes=None, overwrite_x=False):
+    """
+    Return inverse multidimensional discrete Fourier transform.
+
+    The sequence can be of an arbitrary type.
+
+    The returned array contains::
+
+      y[j_1,..,j_d] = 1/p * sum[k_1=0..n_1-1, ..., k_d=0..n_d-1]
+         x[k_1,..,k_d] * prod[i=1..d] exp(sqrt(-1)*2*pi/n_i * j_i * k_i)
+
+    where ``d = len(x.shape)``, ``n = x.shape``, and ``p = prod[i=1..d] n_i``.
+
+    For description of parameters see `fftn`.
+
+    See Also
+    --------
+    fftn : for detailed information.
+
+    Examples
+    --------
+    >>> from scipy.fftpack import fftn, ifftn
+    >>> import numpy as np
+    >>> y = (-np.arange(16), 8 - np.arange(16), np.arange(16))
+    >>> np.allclose(y, ifftn(fftn(y)))
+    True
+
+    """
+    shape = _good_shape(x, shape, axes)
+    return _pocketfft.ifftn(x, shape, axes, None, overwrite_x)
+
+
+def fft2(x, shape=None, axes=(-2,-1), overwrite_x=False):
+    """
+    2-D discrete Fourier transform.
+
+    Return the 2-D discrete Fourier transform of the 2-D argument
+    `x`.
+
+    See Also
+    --------
+    fftn : for detailed information.
+
+    Examples
+    --------
+    >>> import numpy as np
+    >>> from scipy.fftpack import fft2, ifft2
+    >>> y = np.mgrid[:5, :5][0]
+    >>> y
+    array([[0, 0, 0, 0, 0],
+           [1, 1, 1, 1, 1],
+           [2, 2, 2, 2, 2],
+           [3, 3, 3, 3, 3],
+           [4, 4, 4, 4, 4]])
+    >>> np.allclose(y, ifft2(fft2(y)))
+    True
+    """
+    return fftn(x,shape,axes,overwrite_x)
+
+
+def ifft2(x, shape=None, axes=(-2,-1), overwrite_x=False):
+    """
+    2-D discrete inverse Fourier transform of real or complex sequence.
+
+    Return inverse 2-D discrete Fourier transform of
+    arbitrary type sequence x.
+
+    See `ifft` for more information.
+
+    See Also
+    --------
+    fft2, ifft
+
+    Examples
+    --------
+    >>> import numpy as np
+    >>> from scipy.fftpack import fft2, ifft2
+    >>> y = np.mgrid[:5, :5][0]
+    >>> y
+    array([[0, 0, 0, 0, 0],
+           [1, 1, 1, 1, 1],
+           [2, 2, 2, 2, 2],
+           [3, 3, 3, 3, 3],
+           [4, 4, 4, 4, 4]])
+    >>> np.allclose(y, fft2(ifft2(y)))
+    True
+
+    """
+    return ifftn(x,shape,axes,overwrite_x)

venv/lib/python3.12/site-packages/scipy/fftpack/_helper.py

@@ -0,0 +1,115 @@
+import operator
+
+import numpy as np
+from numpy.fft import fftshift, ifftshift, fftfreq
+
+import scipy.fft._pocketfft.helper as _helper
+
+__all__ = ['fftshift', 'ifftshift', 'fftfreq', 'rfftfreq', 'next_fast_len']
+
+
+def rfftfreq(n, d=1.0):
+    """DFT sample frequencies (for usage with rfft, irfft).
+
+    The returned float array contains the frequency bins in
+    cycles/unit (with zero at the start) given a window length `n` and a
+    sample spacing `d`::
+
+      f = [0,1,1,2,2,...,n/2-1,n/2-1,n/2]/(d*n)   if n is even
+      f = [0,1,1,2,2,...,n/2-1,n/2-1,n/2,n/2]/(d*n)   if n is odd
+
+    Parameters
+    ----------
+    n : int
+        Window length.
+    d : scalar, optional
+        Sample spacing. Default is 1.
+
+    Returns
+    -------
+    out : ndarray
+        The array of length `n`, containing the sample frequencies.
+
+    Examples
+    --------
+    >>> import numpy as np
+    >>> from scipy import fftpack
+    >>> sig = np.array([-2, 8, 6, 4, 1, 0, 3, 5], dtype=float)
+    >>> sig_fft = fftpack.rfft(sig)
+    >>> n = sig_fft.size
+    >>> timestep = 0.1
+    >>> freq = fftpack.rfftfreq(n, d=timestep)
+    >>> freq
+    array([ 0.  ,  1.25,  1.25,  2.5 ,  2.5 ,  3.75,  3.75,  5.  ])
+
+    """
+    n = operator.index(n)
+    if n < 0:
+        raise ValueError("n = %s is not valid. "
+                         "n must be a nonnegative integer." % n)
+
+    return (np.arange(1, n + 1, dtype=int) // 2) / float(n * d)
+
+
+def next_fast_len(target):
+    """
+    Find the next fast size of input data to `fft`, for zero-padding, etc.
+
+    SciPy's FFTPACK has efficient functions for radix {2, 3, 4, 5}, so this
+    returns the next composite of the prime factors 2, 3, and 5 which is
+    greater than or equal to `target`. (These are also known as 5-smooth
+    numbers, regular numbers, or Hamming numbers.)
+
+    Parameters
+    ----------
+    target : int
+        Length to start searching from. Must be a positive integer.
+
+    Returns
+    -------
+    out : int
+        The first 5-smooth number greater than or equal to `target`.
+
+    Notes
+    -----
+    .. versionadded:: 0.18.0
+
+    Examples
+    --------
+    On a particular machine, an FFT of prime length takes 133 ms:
+
+    >>> from scipy import fftpack
+    >>> import numpy as np
+    >>> rng = np.random.default_rng()
+    >>> min_len = 10007  # prime length is worst case for speed
+    >>> a = rng.standard_normal(min_len)
+    >>> b = fftpack.fft(a)
+
+    Zero-padding to the next 5-smooth length reduces computation time to
+    211 us, a speedup of 630 times:
+
+    >>> fftpack.next_fast_len(min_len)
+    10125
+    >>> b = fftpack.fft(a, 10125)
+
+    Rounding up to the next power of 2 is not optimal, taking 367 us to
+    compute, 1.7 times as long as the 5-smooth size:
+
+    >>> b = fftpack.fft(a, 16384)
+
+    """
+    # Real transforms use regular sizes so this is backwards compatible
+    return _helper.good_size(target, True)
+
+
+def _good_shape(x, shape, axes):
+    """Ensure that shape argument is valid for scipy.fftpack
+
+    scipy.fftpack does not support len(shape) < x.ndim when axes is not given.
+    """
+    if shape is not None and axes is None:
+        shape = _helper._iterable_of_int(shape, 'shape')
+        if len(shape) != np.ndim(x):
+            raise ValueError("when given, axes and shape arguments"
+                             " have to be of the same length")
+    return shape

venv/lib/python3.12/site-packages/scipy/fftpack/_pseudo_diffs.py

@@ -0,0 +1,551 @@
+"""
+Differential and pseudo-differential operators.
+"""
+# Created by Pearu Peterson, September 2002
+
+__all__ = ['diff',
+           'tilbert','itilbert','hilbert','ihilbert',
+           'cs_diff','cc_diff','sc_diff','ss_diff',
+           'shift']
+
+from numpy import pi, asarray, sin, cos, sinh, cosh, tanh, iscomplexobj
+from . import convolve
+
+from scipy.fft._pocketfft.helper import _datacopied
+
+
+_cache = {}
+
+
+def diff(x,order=1,period=None, _cache=_cache):
+    """
+    Return kth derivative (or integral) of a periodic sequence x.
+
+    If x_j and y_j are Fourier coefficients of periodic functions x
+    and y, respectively, then::
+
+      y_j = pow(sqrt(-1)*j*2*pi/period, order) * x_j
+      y_0 = 0 if order is not 0.
+
+    Parameters
+    ----------
+    x : array_like
+        Input array.
+    order : int, optional
+        The order of differentiation. Default order is 1. If order is
+        negative, then integration is carried out under the assumption
+        that ``x_0 == 0``.
+    period : float, optional
+        The assumed period of the sequence. Default is ``2*pi``.
+
+    Notes
+    -----
+    If ``sum(x, axis=0) = 0`` then ``diff(diff(x, k), -k) == x`` (within
+    numerical accuracy).
+
+    For odd order and even ``len(x)``, the Nyquist mode is taken zero.
+
+    """
+    tmp = asarray(x)
+    if order == 0:
+        return tmp
+    if iscomplexobj(tmp):
+        return diff(tmp.real,order,period)+1j*diff(tmp.imag,order,period)
+    if period is not None:
+        c = 2*pi/period
+    else:
+        c = 1.0
+    n = len(x)
+    omega = _cache.get((n,order,c))
+    if omega is None:
+        if len(_cache) > 20:
+            while _cache:
+                _cache.popitem()
+
+        def kernel(k,order=order,c=c):
+            if k:
+                return pow(c*k,order)
+            return 0
+        omega = convolve.init_convolution_kernel(n,kernel,d=order,
+                                                 zero_nyquist=1)
+        _cache[(n,order,c)] = omega
+    overwrite_x = _datacopied(tmp, x)
+    return convolve.convolve(tmp,omega,swap_real_imag=order % 2,
+                             overwrite_x=overwrite_x)
+
+
+del _cache
+
+
+_cache = {}
+
+
+def tilbert(x, h, period=None, _cache=_cache):
+    """
+    Return h-Tilbert transform of a periodic sequence x.
+
+    If x_j and y_j are Fourier coefficients of periodic functions x
+    and y, respectively, then::
+
+        y_j = sqrt(-1)*coth(j*h*2*pi/period) * x_j
+        y_0 = 0
+
+    Parameters
+    ----------
+    x : array_like
+        The input array to transform.
+    h : float
+        Defines the parameter of the Tilbert transform.
+    period : float, optional
+        The assumed period of the sequence. Default period is ``2*pi``.
+
+    Returns
+    -------
+    tilbert : ndarray
+        The result of the transform.
+
+    Notes
+    -----
+    If ``sum(x, axis=0) == 0`` and ``n = len(x)`` is odd, then
+    ``tilbert(itilbert(x)) == x``.
+
+    If ``2 * pi * h / period`` is approximately 10 or larger, then
+    numerically ``tilbert == hilbert``
+    (theoretically oo-Tilbert == Hilbert).
+
+    For even ``len(x)``, the Nyquist mode of ``x`` is taken zero.
+
+    """
+    tmp = asarray(x)
+    if iscomplexobj(tmp):
+        return tilbert(tmp.real, h, period) + \
+               1j * tilbert(tmp.imag, h, period)
+
+    if period is not None:
+        h = h * 2 * pi / period
+
+    n = len(x)
+    omega = _cache.get((n, h))
+    if omega is None:
+        if len(_cache) > 20:
+            while _cache:
+                _cache.popitem()
+
+        def kernel(k, h=h):
+            if k:
+                return 1.0/tanh(h*k)
+
+            return 0
+
+        omega = convolve.init_convolution_kernel(n, kernel, d=1)
+        _cache[(n,h)] = omega
+
+    overwrite_x = _datacopied(tmp, x)
+    return convolve.convolve(tmp,omega,swap_real_imag=1,overwrite_x=overwrite_x)
+
+
+del _cache
+
+
+_cache = {}
+
+
+def itilbert(x,h,period=None, _cache=_cache):
+    """
+    Return inverse h-Tilbert transform of a periodic sequence x.
+
+    If ``x_j`` and ``y_j`` are Fourier coefficients of periodic functions x
+    and y, respectively, then::
+
+      y_j = -sqrt(-1)*tanh(j*h*2*pi/period) * x_j
+      y_0 = 0
+
+    For more details, see `tilbert`.
+
+    """
+    tmp = asarray(x)
+    if iscomplexobj(tmp):
+        return itilbert(tmp.real,h,period) + \
+               1j*itilbert(tmp.imag,h,period)
+    if period is not None:
+        h = h*2*pi/period
+    n = len(x)
+    omega = _cache.get((n,h))
+    if omega is None:
+        if len(_cache) > 20:
+            while _cache:
+                _cache.popitem()
+
+        def kernel(k,h=h):
+            if k:
+                return -tanh(h*k)
+            return 0
+        omega = convolve.init_convolution_kernel(n,kernel,d=1)
+        _cache[(n,h)] = omega
+    overwrite_x = _datacopied(tmp, x)
+    return convolve.convolve(tmp,omega,swap_real_imag=1,overwrite_x=overwrite_x)
+
+
+del _cache
+
+
+_cache = {}
+
+
+def hilbert(x, _cache=_cache):
+    """
+    Return Hilbert transform of a periodic sequence x.
+
+    If x_j and y_j are Fourier coefficients of periodic functions x
+    and y, respectively, then::
+
+      y_j = sqrt(-1)*sign(j) * x_j
+      y_0 = 0
+
+    Parameters
+    ----------
+    x : array_like
+        The input array, should be periodic.
+    _cache : dict, optional
+        Dictionary that contains the kernel used to do a convolution with.
+
+    Returns
+    -------
+    y : ndarray
+        The transformed input.
+
+    See Also
+    --------
+    scipy.signal.hilbert : Compute the analytic signal, using the Hilbert
+                           transform.
+
+    Notes
+    -----
+    If ``sum(x, axis=0) == 0`` then ``hilbert(ihilbert(x)) == x``.
+
+    For even len(x), the Nyquist mode of x is taken zero.
+
+    The sign of the returned transform does not have a factor -1 that is more
+    often than not found in the definition of the Hilbert transform. Note also
+    that `scipy.signal.hilbert` does have an extra -1 factor compared to this
+    function.
+
+    """
+    tmp = asarray(x)
+    if iscomplexobj(tmp):
+        return hilbert(tmp.real)+1j*hilbert(tmp.imag)
+    n = len(x)
+    omega = _cache.get(n)
+    if omega is None:
+        if len(_cache) > 20:
+            while _cache:
+                _cache.popitem()
+
+        def kernel(k):
+            if k > 0:
+                return 1.0
+            elif k < 0:
+                return -1.0
+            return 0.0
+        omega = convolve.init_convolution_kernel(n,kernel,d=1)
+        _cache[n] = omega
+    overwrite_x = _datacopied(tmp, x)
+    return convolve.convolve(tmp,omega,swap_real_imag=1,overwrite_x=overwrite_x)
+
+
+del _cache
+
+
+def ihilbert(x):
+    """
+    Return inverse Hilbert transform of a periodic sequence x.
+
+    If ``x_j`` and ``y_j`` are Fourier coefficients of periodic functions x
+    and y, respectively, then::
+
+      y_j = -sqrt(-1)*sign(j) * x_j
+      y_0 = 0
+
+    """
+    return -hilbert(x)
+
+
+_cache = {}
+
+
+def cs_diff(x, a, b, period=None, _cache=_cache):
+    """
+    Return (a,b)-cosh/sinh pseudo-derivative of a periodic sequence.
+
+    If ``x_j`` and ``y_j`` are Fourier coefficients of periodic functions x
+    and y, respectively, then::
+
+      y_j = -sqrt(-1)*cosh(j*a*2*pi/period)/sinh(j*b*2*pi/period) * x_j
+      y_0 = 0
+
+    Parameters
+    ----------
+    x : array_like
+        The array to take the pseudo-derivative from.
+    a, b : float
+        Defines the parameters of the cosh/sinh pseudo-differential
+        operator.
+    period : float, optional
+        The period of the sequence. Default period is ``2*pi``.
+
+    Returns
+    -------
+    cs_diff : ndarray
+        Pseudo-derivative of periodic sequence `x`.
+
+    Notes
+    -----
+    For even len(`x`), the Nyquist mode of `x` is taken as zero.
+
+    """
+    tmp = asarray(x)
+    if iscomplexobj(tmp):
+        return cs_diff(tmp.real,a,b,period) + \
+               1j*cs_diff(tmp.imag,a,b,period)
+    if period is not None:
+        a = a*2*pi/period
+        b = b*2*pi/period
+    n = len(x)
+    omega = _cache.get((n,a,b))
+    if omega is None:
+        if len(_cache) > 20:
+            while _cache:
+                _cache.popitem()
+
+        def kernel(k,a=a,b=b):
+            if k:
+                return -cosh(a*k)/sinh(b*k)
+            return 0
+        omega = convolve.init_convolution_kernel(n,kernel,d=1)
+        _cache[(n,a,b)] = omega
+    overwrite_x = _datacopied(tmp, x)
+    return convolve.convolve(tmp,omega,swap_real_imag=1,overwrite_x=overwrite_x)
+
+
+del _cache
+
+
+_cache = {}
+
+
+def sc_diff(x, a, b, period=None, _cache=_cache):
+    """
+    Return (a,b)-sinh/cosh pseudo-derivative of a periodic sequence x.
+
+    If x_j and y_j are Fourier coefficients of periodic functions x
+    and y, respectively, then::
+
+      y_j = sqrt(-1)*sinh(j*a*2*pi/period)/cosh(j*b*2*pi/period) * x_j
+      y_0 = 0
+
+    Parameters
+    ----------
+    x : array_like
+        Input array.
+    a,b : float
+        Defines the parameters of the sinh/cosh pseudo-differential
+        operator.
+    period : float, optional
+        The period of the sequence x. Default is 2*pi.
+
+    Notes
+    -----
+    ``sc_diff(cs_diff(x,a,b),b,a) == x``
+    For even ``len(x)``, the Nyquist mode of x is taken as zero.
+
+    """
+    tmp = asarray(x)
+    if iscomplexobj(tmp):
+        return sc_diff(tmp.real,a,b,period) + \
+               1j*sc_diff(tmp.imag,a,b,period)
+    if period is not None:
+        a = a*2*pi/period
+        b = b*2*pi/period
+    n = len(x)
+    omega = _cache.get((n,a,b))
+    if omega is None:
+        if len(_cache) > 20:
+            while _cache:
+                _cache.popitem()
+
+        def kernel(k,a=a,b=b):
+            if k:
+                return sinh(a*k)/cosh(b*k)
+            return 0
+        omega = convolve.init_convolution_kernel(n,kernel,d=1)
+        _cache[(n,a,b)] = omega
+    overwrite_x = _datacopied(tmp, x)
+    return convolve.convolve(tmp,omega,swap_real_imag=1,overwrite_x=overwrite_x)
+
+
+del _cache
+
+
+_cache = {}
+
+
+def ss_diff(x, a, b, period=None, _cache=_cache):
+    """
+    Return (a,b)-sinh/sinh pseudo-derivative of a periodic sequence x.
+
+    If x_j and y_j are Fourier coefficients of periodic functions x
+    and y, respectively, then::
+
+      y_j = sinh(j*a*2*pi/period)/sinh(j*b*2*pi/period) * x_j
+      y_0 = a/b * x_0
+
+    Parameters
+    ----------
+    x : array_like
+        The array to take the pseudo-derivative from.
+    a,b
+        Defines the parameters of the sinh/sinh pseudo-differential
+        operator.
+    period : float, optional
+        The period of the sequence x. Default is ``2*pi``.
+
+    Notes
+    -----
+    ``ss_diff(ss_diff(x,a,b),b,a) == x``
+
+    """
+    tmp = asarray(x)
+    if iscomplexobj(tmp):
+        return ss_diff(tmp.real,a,b,period) + \
+               1j*ss_diff(tmp.imag,a,b,period)
+    if period is not None:
+        a = a*2*pi/period
+        b = b*2*pi/period
+    n = len(x)
+    omega = _cache.get((n,a,b))
+    if omega is None:
+        if len(_cache) > 20:
+            while _cache:
+                _cache.popitem()
+
+        def kernel(k,a=a,b=b):
+            if k:
+                return sinh(a*k)/sinh(b*k)
+            return float(a)/b
+        omega = convolve.init_convolution_kernel(n,kernel)
+        _cache[(n,a,b)] = omega
+    overwrite_x = _datacopied(tmp, x)
+    return convolve.convolve(tmp,omega,overwrite_x=overwrite_x)
+
+
+del _cache
+
+
+_cache = {}
+
+
+def cc_diff(x, a, b, period=None, _cache=_cache):
+    """
+    Return (a,b)-cosh/cosh pseudo-derivative of a periodic sequence.
+
+    If x_j and y_j are Fourier coefficients of periodic functions x
+    and y, respectively, then::
+
+      y_j = cosh(j*a*2*pi/period)/cosh(j*b*2*pi/period) * x_j
+
+    Parameters
+    ----------
+    x : array_like
+        The array to take the pseudo-derivative from.
+    a,b : float
+        Defines the parameters of the sinh/sinh pseudo-differential
+        operator.
+    period : float, optional
+        The period of the sequence x. Default is ``2*pi``.
+
+    Returns
+    -------
+    cc_diff : ndarray
+        Pseudo-derivative of periodic sequence `x`.
+
+    Notes
+    -----
+    ``cc_diff(cc_diff(x,a,b),b,a) == x``
+
+    """
+    tmp = asarray(x)
+    if iscomplexobj(tmp):
+        return cc_diff(tmp.real,a,b,period) + \
+               1j*cc_diff(tmp.imag,a,b,period)
+    if period is not None:
+        a = a*2*pi/period
+        b = b*2*pi/period
+    n = len(x)
+    omega = _cache.get((n,a,b))
+    if omega is None:
+        if len(_cache) > 20:
+            while _cache:
+                _cache.popitem()
+
+        def kernel(k,a=a,b=b):
+            return cosh(a*k)/cosh(b*k)
+        omega = convolve.init_convolution_kernel(n,kernel)
+        _cache[(n,a,b)] = omega
+    overwrite_x = _datacopied(tmp, x)
+    return convolve.convolve(tmp,omega,overwrite_x=overwrite_x)
+
+
+del _cache
+
+
+_cache = {}
+
+
+def shift(x, a, period=None, _cache=_cache):
+    """
+    Shift periodic sequence x by a: y(u) = x(u+a).
+
+    If x_j and y_j are Fourier coefficients of periodic functions x
+    and y, respectively, then::
+
+          y_j = exp(j*a*2*pi/period*sqrt(-1)) * x_f
+
+    Parameters
+    ----------
+    x : array_like
+        The array to take the pseudo-derivative from.
+    a : float
+        Defines the parameters of the sinh/sinh pseudo-differential
+    period : float, optional
+        The period of the sequences x and y. Default period is ``2*pi``.
+    """
+    tmp = asarray(x)
+    if iscomplexobj(tmp):
+        return shift(tmp.real,a,period)+1j*shift(tmp.imag,a,period)
+    if period is not None:
+        a = a*2*pi/period
+    n = len(x)
+    omega = _cache.get((n,a))
+    if omega is None:
+        if len(_cache) > 20:
+            while _cache:
+                _cache.popitem()
+
+        def kernel_real(k,a=a):
+            return cos(a*k)
+
+        def kernel_imag(k,a=a):
+            return sin(a*k)
+        omega_real = convolve.init_convolution_kernel(n,kernel_real,d=0,
+                                                      zero_nyquist=0)
+        omega_imag = convolve.init_convolution_kernel(n,kernel_imag,d=1,
+                                                      zero_nyquist=0)
+        _cache[(n,a)] = omega_real,omega_imag
+    else:
+        omega_real,omega_imag = omega
+    overwrite_x = _datacopied(tmp, x)
+    return convolve.convolve_z(tmp,omega_real,omega_imag,
+                               overwrite_x=overwrite_x)
+
+
+del _cache

venv/lib/python3.12/site-packages/scipy/fftpack/_realtransforms.py

@@ -0,0 +1,598 @@
+"""
+Real spectrum transforms (DCT, DST, MDCT)
+"""
+
+__all__ = ['dct', 'idct', 'dst', 'idst', 'dctn', 'idctn', 'dstn', 'idstn']
+
+from scipy.fft import _pocketfft
+from ._helper import _good_shape
+
+_inverse_typemap = {1: 1, 2: 3, 3: 2, 4: 4}
+
+
+def dctn(x, type=2, shape=None, axes=None, norm=None, overwrite_x=False):
+    """
+    Return multidimensional Discrete Cosine Transform along the specified axes.
+
+    Parameters
+    ----------
+    x : array_like
+        The input array.
+    type : {1, 2, 3, 4}, optional
+        Type of the DCT (see Notes). Default type is 2.
+    shape : int or array_like of ints or None, optional
+        The shape of the result. If both `shape` and `axes` (see below) are
+        None, `shape` is ``x.shape``; if `shape` is None but `axes` is
+        not None, then `shape` is ``numpy.take(x.shape, axes, axis=0)``.
+        If ``shape[i] > x.shape[i]``, the ith dimension is padded with zeros.
+        If ``shape[i] < x.shape[i]``, the ith dimension is truncated to
+        length ``shape[i]``.
+        If any element of `shape` is -1, the size of the corresponding
+        dimension of `x` is used.
+    axes : int or array_like of ints or None, optional
+        Axes along which the DCT is computed.
+        The default is over all axes.
+    norm : {None, 'ortho'}, optional
+        Normalization mode (see Notes). Default is None.
+    overwrite_x : bool, optional
+        If True, the contents of `x` can be destroyed; the default is False.
+
+    Returns
+    -------
+    y : ndarray of real
+        The transformed input array.
+
+    See Also
+    --------
+    idctn : Inverse multidimensional DCT
+
+    Notes
+    -----
+    For full details of the DCT types and normalization modes, as well as
+    references, see `dct`.
+
+    Examples
+    --------
+    >>> import numpy as np
+    >>> from scipy.fftpack import dctn, idctn
+    >>> rng = np.random.default_rng()
+    >>> y = rng.standard_normal((16, 16))
+    >>> np.allclose(y, idctn(dctn(y, norm='ortho'), norm='ortho'))
+    True
+
+    """
+    shape = _good_shape(x, shape, axes)
+    return _pocketfft.dctn(x, type, shape, axes, norm, overwrite_x)
+
+
+def idctn(x, type=2, shape=None, axes=None, norm=None, overwrite_x=False):
+    """
+    Return multidimensional Discrete Cosine Transform along the specified axes.
+
+    Parameters
+    ----------
+    x : array_like
+        The input array.
+    type : {1, 2, 3, 4}, optional
+        Type of the DCT (see Notes). Default type is 2.
+    shape : int or array_like of ints or None, optional
+        The shape of the result.  If both `shape` and `axes` (see below) are
+        None, `shape` is ``x.shape``; if `shape` is None but `axes` is
+        not None, then `shape` is ``numpy.take(x.shape, axes, axis=0)``.
+        If ``shape[i] > x.shape[i]``, the ith dimension is padded with zeros.
+        If ``shape[i] < x.shape[i]``, the ith dimension is truncated to
+        length ``shape[i]``.
+        If any element of `shape` is -1, the size of the corresponding
+        dimension of `x` is used.
+    axes : int or array_like of ints or None, optional
+        Axes along which the IDCT is computed.
+        The default is over all axes.
+    norm : {None, 'ortho'}, optional
+        Normalization mode (see Notes). Default is None.
+    overwrite_x : bool, optional
+        If True, the contents of `x` can be destroyed; the default is False.
+
+    Returns
+    -------
+    y : ndarray of real
+        The transformed input array.
+
+    See Also
+    --------
+    dctn : multidimensional DCT
+
+    Notes
+    -----
+    For full details of the IDCT types and normalization modes, as well as
+    references, see `idct`.
+
+    Examples
+    --------
+    >>> import numpy as np
+    >>> from scipy.fftpack import dctn, idctn
+    >>> rng = np.random.default_rng()
+    >>> y = rng.standard_normal((16, 16))
+    >>> np.allclose(y, idctn(dctn(y, norm='ortho'), norm='ortho'))
+    True
+
+    """
+    type = _inverse_typemap[type]
+    shape = _good_shape(x, shape, axes)
+    return _pocketfft.dctn(x, type, shape, axes, norm, overwrite_x)
+
+
+def dstn(x, type=2, shape=None, axes=None, norm=None, overwrite_x=False):
+    """
+    Return multidimensional Discrete Sine Transform along the specified axes.
+
+    Parameters
+    ----------
+    x : array_like
+        The input array.
+    type : {1, 2, 3, 4}, optional
+        Type of the DST (see Notes). Default type is 2.
+    shape : int or array_like of ints or None, optional
+        The shape of the result.  If both `shape` and `axes` (see below) are
+        None, `shape` is ``x.shape``; if `shape` is None but `axes` is
+        not None, then `shape` is ``numpy.take(x.shape, axes, axis=0)``.
+        If ``shape[i] > x.shape[i]``, the ith dimension is padded with zeros.
+        If ``shape[i] < x.shape[i]``, the ith dimension is truncated to
+        length ``shape[i]``.
+        If any element of `shape` is -1, the size of the corresponding
+        dimension of `x` is used.
+    axes : int or array_like of ints or None, optional
+        Axes along which the DCT is computed.
+        The default is over all axes.
+    norm : {None, 'ortho'}, optional
+        Normalization mode (see Notes). Default is None.
+    overwrite_x : bool, optional
+        If True, the contents of `x` can be destroyed; the default is False.
+
+    Returns
+    -------
+    y : ndarray of real
+        The transformed input array.
+
+    See Also
+    --------
+    idstn : Inverse multidimensional DST
+
+    Notes
+    -----
+    For full details of the DST types and normalization modes, as well as
+    references, see `dst`.
+
+    Examples
+    --------
+    >>> import numpy as np
+    >>> from scipy.fftpack import dstn, idstn
+    >>> rng = np.random.default_rng()
+    >>> y = rng.standard_normal((16, 16))
+    >>> np.allclose(y, idstn(dstn(y, norm='ortho'), norm='ortho'))
+    True
+
+    """
+    shape = _good_shape(x, shape, axes)
+    return _pocketfft.dstn(x, type, shape, axes, norm, overwrite_x)
+
+
+def idstn(x, type=2, shape=None, axes=None, norm=None, overwrite_x=False):
+    """
+    Return multidimensional Discrete Sine Transform along the specified axes.
+
+    Parameters
+    ----------
+    x : array_like
+        The input array.
+    type : {1, 2, 3, 4}, optional
+        Type of the DST (see Notes). Default type is 2.
+    shape : int or array_like of ints or None, optional
+        The shape of the result.  If both `shape` and `axes` (see below) are
+        None, `shape` is ``x.shape``; if `shape` is None but `axes` is
+        not None, then `shape` is ``numpy.take(x.shape, axes, axis=0)``.
+        If ``shape[i] > x.shape[i]``, the ith dimension is padded with zeros.
+        If ``shape[i] < x.shape[i]``, the ith dimension is truncated to
+        length ``shape[i]``.
+        If any element of `shape` is -1, the size of the corresponding
+        dimension of `x` is used.
+    axes : int or array_like of ints or None, optional
+        Axes along which the IDST is computed.
+        The default is over all axes.
+    norm : {None, 'ortho'}, optional
+        Normalization mode (see Notes). Default is None.
+    overwrite_x : bool, optional
+        If True, the contents of `x` can be destroyed; the default is False.
+
+    Returns
+    -------
+    y : ndarray of real
+        The transformed input array.
+
+    See Also
+    --------
+    dstn : multidimensional DST
+
+    Notes
+    -----
+    For full details of the IDST types and normalization modes, as well as
+    references, see `idst`.
+
+    Examples
+    --------
+    >>> import numpy as np
+    >>> from scipy.fftpack import dstn, idstn
+    >>> rng = np.random.default_rng()
+    >>> y = rng.standard_normal((16, 16))
+    >>> np.allclose(y, idstn(dstn(y, norm='ortho'), norm='ortho'))
+    True
+
+    """
+    type = _inverse_typemap[type]
+    shape = _good_shape(x, shape, axes)
+    return _pocketfft.dstn(x, type, shape, axes, norm, overwrite_x)
+
+
+def dct(x, type=2, n=None, axis=-1, norm=None, overwrite_x=False):
+    r"""
+    Return the Discrete Cosine Transform of arbitrary type sequence x.
+
+    Parameters
+    ----------
+    x : array_like
+        The input array.
+    type : {1, 2, 3, 4}, optional
+        Type of the DCT (see Notes). Default type is 2.
+    n : int, optional
+        Length of the transform.  If ``n < x.shape[axis]``, `x` is
+        truncated.  If ``n > x.shape[axis]``, `x` is zero-padded. The
+        default results in ``n = x.shape[axis]``.
+    axis : int, optional
+        Axis along which the dct is computed; the default is over the
+        last axis (i.e., ``axis=-1``).
+    norm : {None, 'ortho'}, optional
+        Normalization mode (see Notes). Default is None.
+    overwrite_x : bool, optional
+        If True, the contents of `x` can be destroyed; the default is False.
+
+    Returns
+    -------
+    y : ndarray of real
+        The transformed input array.
+
+    See Also
+    --------
+    idct : Inverse DCT
+
+    Notes
+    -----
+    For a single dimension array ``x``, ``dct(x, norm='ortho')`` is equal to
+    MATLAB ``dct(x)``.
+
+    There are, theoretically, 8 types of the DCT, only the first 4 types are
+    implemented in scipy. 'The' DCT generally refers to DCT type 2, and 'the'
+    Inverse DCT generally refers to DCT type 3.
+
+    **Type I**
+
+    There are several definitions of the DCT-I; we use the following
+    (for ``norm=None``)
+
+    .. math::
+
+       y_k = x_0 + (-1)^k x_{N-1} + 2 \sum_{n=1}^{N-2} x_n \cos\left(
+       \frac{\pi k n}{N-1} \right)
+
+    If ``norm='ortho'``, ``x[0]`` and ``x[N-1]`` are multiplied by a scaling
+    factor of :math:`\sqrt{2}`, and ``y[k]`` is multiplied by a scaling factor
+    ``f``
+
+    .. math::
+
+        f = \begin{cases}
+         \frac{1}{2}\sqrt{\frac{1}{N-1}} & \text{if }k=0\text{ or }N-1, \\
+         \frac{1}{2}\sqrt{\frac{2}{N-1}} & \text{otherwise} \end{cases}
+
+    .. versionadded:: 1.2.0
+       Orthonormalization in DCT-I.
+
+    .. note::
+       The DCT-I is only supported for input size > 1.
+
+    **Type II**
+
+    There are several definitions of the DCT-II; we use the following
+    (for ``norm=None``)
+
+    .. math::
+
+       y_k = 2 \sum_{n=0}^{N-1} x_n \cos\left(\frac{\pi k(2n+1)}{2N} \right)
+
+    If ``norm='ortho'``, ``y[k]`` is multiplied by a scaling factor ``f``
+
+    .. math::
+       f = \begin{cases}
+       \sqrt{\frac{1}{4N}} & \text{if }k=0, \\
+       \sqrt{\frac{1}{2N}} & \text{otherwise} \end{cases}
+
+    which makes the corresponding matrix of coefficients orthonormal
+    (``O @ O.T = np.eye(N)``).
+
+    **Type III**
+
+    There are several definitions, we use the following (for ``norm=None``)
+
+    .. math::
+
+       y_k = x_0 + 2 \sum_{n=1}^{N-1} x_n \cos\left(\frac{\pi(2k+1)n}{2N}\right)
+
+    or, for ``norm='ortho'``
+
+    .. math::
+
+       y_k = \frac{x_0}{\sqrt{N}} + \sqrt{\frac{2}{N}} \sum_{n=1}^{N-1} x_n
+       \cos\left(\frac{\pi(2k+1)n}{2N}\right)
+
+    The (unnormalized) DCT-III is the inverse of the (unnormalized) DCT-II, up
+    to a factor `2N`. The orthonormalized DCT-III is exactly the inverse of
+    the orthonormalized DCT-II.
+
+    **Type IV**
+
+    There are several definitions of the DCT-IV; we use the following
+    (for ``norm=None``)
+
+    .. math::
+
+       y_k = 2 \sum_{n=0}^{N-1} x_n \cos\left(\frac{\pi(2k+1)(2n+1)}{4N} \right)
+
+    If ``norm='ortho'``, ``y[k]`` is multiplied by a scaling factor ``f``
+
+    .. math::
+
+        f = \frac{1}{\sqrt{2N}}
+
+    .. versionadded:: 1.2.0
+       Support for DCT-IV.
+
+    References
+    ----------
+    .. [1] 'A Fast Cosine Transform in One and Two Dimensions', by J.
+           Makhoul, `IEEE Transactions on acoustics, speech and signal
+           processing` vol. 28(1), pp. 27-34,
+           :doi:`10.1109/TASSP.1980.1163351` (1980).
+    .. [2] Wikipedia, "Discrete cosine transform",
+           https://en.wikipedia.org/wiki/Discrete_cosine_transform
+
+    Examples
+    --------
+    The Type 1 DCT is equivalent to the FFT (though faster) for real,
+    even-symmetrical inputs. The output is also real and even-symmetrical.
+    Half of the FFT input is used to generate half of the FFT output:
+
+    >>> from scipy.fftpack import fft, dct
+    >>> import numpy as np
+    >>> fft(np.array([4., 3., 5., 10., 5., 3.])).real
+    array([ 30.,  -8.,   6.,  -2.,   6.,  -8.])
+    >>> dct(np.array([4., 3., 5., 10.]), 1)
+    array([ 30.,  -8.,   6.,  -2.])
+
+    """
+    return _pocketfft.dct(x, type, n, axis, norm, overwrite_x)
+
+
+def idct(x, type=2, n=None, axis=-1, norm=None, overwrite_x=False):
+    """
+    Return the Inverse Discrete Cosine Transform of an arbitrary type sequence.
+
+    Parameters
+    ----------
+    x : array_like
+        The input array.
+    type : {1, 2, 3, 4}, optional
+        Type of the DCT (see Notes). Default type is 2.
+    n : int, optional
+        Length of the transform.  If ``n < x.shape[axis]``, `x` is
+        truncated.  If ``n > x.shape[axis]``, `x` is zero-padded. The
+        default results in ``n = x.shape[axis]``.
+    axis : int, optional
+        Axis along which the idct is computed; the default is over the
+        last axis (i.e., ``axis=-1``).
+    norm : {None, 'ortho'}, optional
+        Normalization mode (see Notes). Default is None.
+    overwrite_x : bool, optional
+        If True, the contents of `x` can be destroyed; the default is False.
+
+    Returns
+    -------
+    idct : ndarray of real
+        The transformed input array.
+
+    See Also
+    --------
+    dct : Forward DCT
+
+    Notes
+    -----
+    For a single dimension array `x`, ``idct(x, norm='ortho')`` is equal to
+    MATLAB ``idct(x)``.
+
+    'The' IDCT is the IDCT of type 2, which is the same as DCT of type 3.
+
+    IDCT of type 1 is the DCT of type 1, IDCT of type 2 is the DCT of type
+    3, and IDCT of type 3 is the DCT of type 2. IDCT of type 4 is the DCT
+    of type 4. For the definition of these types, see `dct`.
+
+    Examples
+    --------
+    The Type 1 DCT is equivalent to the DFT for real, even-symmetrical
+    inputs. The output is also real and even-symmetrical. Half of the IFFT
+    input is used to generate half of the IFFT output:
+
+    >>> from scipy.fftpack import ifft, idct
+    >>> import numpy as np
+    >>> ifft(np.array([ 30.,  -8.,   6.,  -2.,   6.,  -8.])).real
+    array([  4.,   3.,   5.,  10.,   5.,   3.])
+    >>> idct(np.array([ 30.,  -8.,   6.,  -2.]), 1) / 6
+    array([  4.,   3.,   5.,  10.])
+
+    """
+    type = _inverse_typemap[type]
+    return _pocketfft.dct(x, type, n, axis, norm, overwrite_x)
+
+
+def dst(x, type=2, n=None, axis=-1, norm=None, overwrite_x=False):
+    r"""
+    Return the Discrete Sine Transform of arbitrary type sequence x.
+
+    Parameters
+    ----------
+    x : array_like
+        The input array.
+    type : {1, 2, 3, 4}, optional
+        Type of the DST (see Notes). Default type is 2.
+    n : int, optional
+        Length of the transform.  If ``n < x.shape[axis]``, `x` is
+        truncated.  If ``n > x.shape[axis]``, `x` is zero-padded. The
+        default results in ``n = x.shape[axis]``.
+    axis : int, optional
+        Axis along which the dst is computed; the default is over the
+        last axis (i.e., ``axis=-1``).
+    norm : {None, 'ortho'}, optional
+        Normalization mode (see Notes). Default is None.
+    overwrite_x : bool, optional
+        If True, the contents of `x` can be destroyed; the default is False.
+
+    Returns
+    -------
+    dst : ndarray of reals
+        The transformed input array.
+
+    See Also
+    --------
+    idst : Inverse DST
+
+    Notes
+    -----
+    For a single dimension array ``x``.
+
+    There are, theoretically, 8 types of the DST for different combinations of
+    even/odd boundary conditions and boundary off sets [1]_, only the first
+    4 types are implemented in scipy.
+
+    **Type I**
+
+    There are several definitions of the DST-I; we use the following
+    for ``norm=None``. DST-I assumes the input is odd around `n=-1` and `n=N`.
+
+    .. math::
+
+        y_k = 2 \sum_{n=0}^{N-1} x_n \sin\left(\frac{\pi(k+1)(n+1)}{N+1}\right)
+
+    Note that the DST-I is only supported for input size > 1.
+    The (unnormalized) DST-I is its own inverse, up to a factor `2(N+1)`.
+    The orthonormalized DST-I is exactly its own inverse.
+
+    **Type II**
+
+    There are several definitions of the DST-II; we use the following for
+    ``norm=None``. DST-II assumes the input is odd around `n=-1/2` and
+    `n=N-1/2`; the output is odd around :math:`k=-1` and even around `k=N-1`
+
+    .. math::
+
+        y_k = 2 \sum_{n=0}^{N-1} x_n \sin\left(\frac{\pi(k+1)(2n+1)}{2N}\right)
+
+    if ``norm='ortho'``, ``y[k]`` is multiplied by a scaling factor ``f``
+
+    .. math::
+
+        f = \begin{cases}
+        \sqrt{\frac{1}{4N}} & \text{if }k = 0, \\
+        \sqrt{\frac{1}{2N}} & \text{otherwise} \end{cases}
+
+    **Type III**
+
+    There are several definitions of the DST-III, we use the following (for
+    ``norm=None``). DST-III assumes the input is odd around `n=-1` and even
+    around `n=N-1`
+
+    .. math::
+
+        y_k = (-1)^k x_{N-1} + 2 \sum_{n=0}^{N-2} x_n \sin\left(
+        \frac{\pi(2k+1)(n+1)}{2N}\right)
+
+    The (unnormalized) DST-III is the inverse of the (unnormalized) DST-II, up
+    to a factor `2N`. The orthonormalized DST-III is exactly the inverse of the
+    orthonormalized DST-II.
+
+    .. versionadded:: 0.11.0
+
+    **Type IV**
+
+    There are several definitions of the DST-IV, we use the following (for
+    ``norm=None``). DST-IV assumes the input is odd around `n=-0.5` and even
+    around `n=N-0.5`
+
+    .. math::
+
+        y_k = 2 \sum_{n=0}^{N-1} x_n \sin\left(\frac{\pi(2k+1)(2n+1)}{4N}\right)
+
+    The (unnormalized) DST-IV is its own inverse, up to a factor `2N`. The
+    orthonormalized DST-IV is exactly its own inverse.
+
+    .. versionadded:: 1.2.0
+       Support for DST-IV.
+
+    References
+    ----------
+    .. [1] Wikipedia, "Discrete sine transform",
+           https://en.wikipedia.org/wiki/Discrete_sine_transform
+
+    """
+    return _pocketfft.dst(x, type, n, axis, norm, overwrite_x)
+
+
+def idst(x, type=2, n=None, axis=-1, norm=None, overwrite_x=False):
+    """
+    Return the Inverse Discrete Sine Transform of an arbitrary type sequence.
+
+    Parameters
+    ----------
+    x : array_like
+        The input array.
+    type : {1, 2, 3, 4}, optional
+        Type of the DST (see Notes). Default type is 2.
+    n : int, optional
+        Length of the transform.  If ``n < x.shape[axis]``, `x` is
+        truncated. If ``n > x.shape[axis]``, `x` is zero-padded. The
+        default results in ``n = x.shape[axis]``.
+    axis : int, optional
+        Axis along which the idst is computed; the default is over the
+        last axis (i.e., ``axis=-1``).
+    norm : {None, 'ortho'}, optional
+        Normalization mode (see Notes). Default is None.
+    overwrite_x : bool, optional
+        If True, the contents of `x` can be destroyed; the default is False.
+
+    Returns
+    -------
+    idst : ndarray of real
+        The transformed input array.
+
+    See Also
+    --------
+    dst : Forward DST
+
+    Notes
+    -----
+    'The' IDST is the IDST of type 2, which is the same as DST of type 3.
+
+    IDST of type 1 is the DST of type 1, IDST of type 2 is the DST of type
+    3, and IDST of type 3 is the DST of type 2. For the definition of these
+    types, see `dst`.
+
+    .. versionadded:: 0.11.0
+
+    """
+    type = _inverse_typemap[type]
+    return _pocketfft.dst(x, type, n, axis, norm, overwrite_x)

venv/lib/python3.12/site-packages/scipy/fftpack/basic.py

@@ -0,0 +1,20 @@
+# This file is not meant for public use and will be removed in SciPy v2.0.0.
+# Use the `scipy.fftpack` namespace for importing the functions
+# included below.
+
+from scipy._lib.deprecation import _sub_module_deprecation
+
+__all__ = [  # noqa: F822
+    'fft','ifft','fftn','ifftn','rfft','irfft',
+    'fft2','ifft2'
+]
+
+
+def __dir__():
+    return __all__
+
+
+def __getattr__(name):
+    return _sub_module_deprecation(sub_package="fftpack", module="basic",
+                                   private_modules=["_basic"], all=__all__,
+                                   attribute=name)

venv/lib/python3.12/site-packages/scipy/fftpack/helper.py

@@ -0,0 +1,19 @@
+# This file is not meant for public use and will be removed in SciPy v2.0.0.
+# Use the `scipy.fftpack` namespace for importing the functions
+# included below.
+
+from scipy._lib.deprecation import _sub_module_deprecation
+
+__all__ = [  # noqa: F822
+    'fftshift', 'ifftshift', 'fftfreq', 'rfftfreq', 'next_fast_len'
+]
+
+
+def __dir__():
+    return __all__
+
+
+def __getattr__(name):
+    return _sub_module_deprecation(sub_package="fftpack", module="helper",
+                                   private_modules=["_helper"], all=__all__,
+                                   attribute=name)

venv/lib/python3.12/site-packages/scipy/fftpack/pseudo_diffs.py

@@ -0,0 +1,22 @@
+# This file is not meant for public use and will be removed in SciPy v2.0.0.
+# Use the `scipy.fftpack` namespace for importing the functions
+# included below.
+
+from scipy._lib.deprecation import _sub_module_deprecation
+
+__all__ = [  # noqa: F822
+    'diff',
+    'tilbert', 'itilbert', 'hilbert', 'ihilbert',
+    'cs_diff', 'cc_diff', 'sc_diff', 'ss_diff',
+    'shift', 'convolve'
+]
+
+
+def __dir__():
+    return __all__
+
+
+def __getattr__(name):
+    return _sub_module_deprecation(sub_package="fftpack", module="pseudo_diffs",
+                                   private_modules=["_pseudo_diffs"], all=__all__,
+                                   attribute=name)

venv/lib/python3.12/site-packages/scipy/fftpack/realtransforms.py

@@ -0,0 +1,19 @@
+# This file is not meant for public use and will be removed in SciPy v2.0.0.
+# Use the `scipy.fftpack` namespace for importing the functions
+# included below.
+
+from scipy._lib.deprecation import _sub_module_deprecation
+
+__all__ = [  # noqa: F822
+    'dct', 'idct', 'dst', 'idst', 'dctn', 'idctn', 'dstn', 'idstn'
+]
+
+
+def __dir__():
+    return __all__
+
+
+def __getattr__(name):
+    return _sub_module_deprecation(sub_package="fftpack", module="realtransforms",
+                                   private_modules=["_realtransforms"], all=__all__,
+                                   attribute=name)

venv/lib/python3.12/site-packages/scipy/fftpack/tests/test_basic.py

@@ -0,0 +1,873 @@
+# Created by Pearu Peterson, September 2002
+
+from numpy.testing import (assert_, assert_equal, assert_array_almost_equal,
+                           assert_array_almost_equal_nulp, assert_array_less)
+import pytest
+from pytest import raises as assert_raises
+from scipy.fftpack import ifft, fft, fftn, ifftn, rfft, irfft, fft2
+
+from numpy import (arange, array, asarray, zeros, dot, exp, pi,
+                   swapaxes, double, cdouble)
+import numpy as np
+import numpy.fft
+from numpy.random import rand
+
+# "large" composite numbers supported by FFTPACK
+LARGE_COMPOSITE_SIZES = [
+    2**13,
+    2**5 * 3**5,
+    2**3 * 3**3 * 5**2,
+]
+SMALL_COMPOSITE_SIZES = [
+    2,
+    2*3*5,
+    2*2*3*3,
+]
+# prime
+LARGE_PRIME_SIZES = [
+    2011
+]
+SMALL_PRIME_SIZES = [
+    29
+]
+
+
+def _assert_close_in_norm(x, y, rtol, size, rdt):
+    # helper function for testing
+    err_msg = f"size: {size}  rdt: {rdt}"
+    assert_array_less(np.linalg.norm(x - y), rtol*np.linalg.norm(x), err_msg)
+
+
+def random(size):
+    return rand(*size)
+
+
+def direct_dft(x):
+    x = asarray(x)
+    n = len(x)
+    y = zeros(n, dtype=cdouble)
+    w = -arange(n)*(2j*pi/n)
+    for i in range(n):
+        y[i] = dot(exp(i*w), x)
+    return y
+
+
+def direct_idft(x):
+    x = asarray(x)
+    n = len(x)
+    y = zeros(n, dtype=cdouble)
+    w = arange(n)*(2j*pi/n)
+    for i in range(n):
+        y[i] = dot(exp(i*w), x)/n
+    return y
+
+
+def direct_dftn(x):
+    x = asarray(x)
+    for axis in range(len(x.shape)):
+        x = fft(x, axis=axis)
+    return x
+
+
+def direct_idftn(x):
+    x = asarray(x)
+    for axis in range(len(x.shape)):
+        x = ifft(x, axis=axis)
+    return x
+
+
+def direct_rdft(x):
+    x = asarray(x)
+    n = len(x)
+    w = -arange(n)*(2j*pi/n)
+    r = zeros(n, dtype=double)
+    for i in range(n//2+1):
+        y = dot(exp(i*w), x)
+        if i:
+            r[2*i-1] = y.real
+            if 2*i < n:
+                r[2*i] = y.imag
+        else:
+            r[0] = y.real
+    return r
+
+
+def direct_irdft(x):
+    x = asarray(x)
+    n = len(x)
+    x1 = zeros(n, dtype=cdouble)
+    for i in range(n//2+1):
+        if i:
+            if 2*i < n:
+                x1[i] = x[2*i-1] + 1j*x[2*i]
+                x1[n-i] = x[2*i-1] - 1j*x[2*i]
+            else:
+                x1[i] = x[2*i-1]
+        else:
+            x1[0] = x[0]
+    return direct_idft(x1).real
+
+
+class _TestFFTBase:
+    def setup_method(self):
+        self.cdt = None
+        self.rdt = None
+        np.random.seed(1234)
+
+    def test_definition(self):
+        x = np.array([1,2,3,4+1j,1,2,3,4+2j], dtype=self.cdt)
+        y = fft(x)
+        assert_equal(y.dtype, self.cdt)
+        y1 = direct_dft(x)
+        assert_array_almost_equal(y,y1)
+        x = np.array([1,2,3,4+0j,5], dtype=self.cdt)
+        assert_array_almost_equal(fft(x),direct_dft(x))
+
+    def test_n_argument_real(self):
+        x1 = np.array([1,2,3,4], dtype=self.rdt)
+        x2 = np.array([1,2,3,4], dtype=self.rdt)
+        y = fft([x1,x2],n=4)
+        assert_equal(y.dtype, self.cdt)
+        assert_equal(y.shape,(2,4))
+        assert_array_almost_equal(y[0],direct_dft(x1))
+        assert_array_almost_equal(y[1],direct_dft(x2))
+
+    def _test_n_argument_complex(self):
+        x1 = np.array([1,2,3,4+1j], dtype=self.cdt)
+        x2 = np.array([1,2,3,4+1j], dtype=self.cdt)
+        y = fft([x1,x2],n=4)
+        assert_equal(y.dtype, self.cdt)
+        assert_equal(y.shape,(2,4))
+        assert_array_almost_equal(y[0],direct_dft(x1))
+        assert_array_almost_equal(y[1],direct_dft(x2))
+
+    def test_invalid_sizes(self):
+        assert_raises(ValueError, fft, [])
+        assert_raises(ValueError, fft, [[1,1],[2,2]], -5)
+
+
+class TestDoubleFFT(_TestFFTBase):
+    def setup_method(self):
+        self.cdt = np.complex128
+        self.rdt = np.float64
+
+
+class TestSingleFFT(_TestFFTBase):
+    def setup_method(self):
+        self.cdt = np.complex64
+        self.rdt = np.float32
+
+    reason = ("single-precision FFT implementation is partially disabled, "
+              "until accuracy issues with large prime powers are resolved")
+
+    @pytest.mark.xfail(run=False, reason=reason)
+    def test_notice(self):
+        pass
+
+
+class TestFloat16FFT:
+
+    def test_1_argument_real(self):
+        x1 = np.array([1, 2, 3, 4], dtype=np.float16)
+        y = fft(x1, n=4)
+        assert_equal(y.dtype, np.complex64)
+        assert_equal(y.shape, (4, ))
+        assert_array_almost_equal(y, direct_dft(x1.astype(np.float32)))
+
+    def test_n_argument_real(self):
+        x1 = np.array([1, 2, 3, 4], dtype=np.float16)
+        x2 = np.array([1, 2, 3, 4], dtype=np.float16)
+        y = fft([x1, x2], n=4)
+        assert_equal(y.dtype, np.complex64)
+        assert_equal(y.shape, (2, 4))
+        assert_array_almost_equal(y[0], direct_dft(x1.astype(np.float32)))
+        assert_array_almost_equal(y[1], direct_dft(x2.astype(np.float32)))
+
+
+class _TestIFFTBase:
+    def setup_method(self):
+        np.random.seed(1234)
+
+    def test_definition(self):
+        x = np.array([1,2,3,4+1j,1,2,3,4+2j], self.cdt)
+        y = ifft(x)
+        y1 = direct_idft(x)
+        assert_equal(y.dtype, self.cdt)
+        assert_array_almost_equal(y,y1)
+
+        x = np.array([1,2,3,4+0j,5], self.cdt)
+        assert_array_almost_equal(ifft(x),direct_idft(x))
+
+    def test_definition_real(self):
+        x = np.array([1,2,3,4,1,2,3,4], self.rdt)
+        y = ifft(x)
+        assert_equal(y.dtype, self.cdt)
+        y1 = direct_idft(x)
+        assert_array_almost_equal(y,y1)
+
+        x = np.array([1,2,3,4,5], dtype=self.rdt)
+        assert_equal(y.dtype, self.cdt)
+        assert_array_almost_equal(ifft(x),direct_idft(x))
+
+    def test_random_complex(self):
+        for size in [1,51,111,100,200,64,128,256,1024]:
+            x = random([size]).astype(self.cdt)
+            x = random([size]).astype(self.cdt) + 1j*x
+            y1 = ifft(fft(x))
+            y2 = fft(ifft(x))
+            assert_equal(y1.dtype, self.cdt)
+            assert_equal(y2.dtype, self.cdt)
+            assert_array_almost_equal(y1, x)
+            assert_array_almost_equal(y2, x)
+
+    def test_random_real(self):
+        for size in [1,51,111,100,200,64,128,256,1024]:
+            x = random([size]).astype(self.rdt)
+            y1 = ifft(fft(x))
+            y2 = fft(ifft(x))
+            assert_equal(y1.dtype, self.cdt)
+            assert_equal(y2.dtype, self.cdt)
+            assert_array_almost_equal(y1, x)
+            assert_array_almost_equal(y2, x)
+
+    def test_size_accuracy(self):
+        # Sanity check for the accuracy for prime and non-prime sized inputs
+        if self.rdt == np.float32:
+            rtol = 1e-5
+        elif self.rdt == np.float64:
+            rtol = 1e-10
+
+        for size in LARGE_COMPOSITE_SIZES + LARGE_PRIME_SIZES:
+            np.random.seed(1234)
+            x = np.random.rand(size).astype(self.rdt)
+            y = ifft(fft(x))
+            _assert_close_in_norm(x, y, rtol, size, self.rdt)
+            y = fft(ifft(x))
+            _assert_close_in_norm(x, y, rtol, size, self.rdt)
+
+            x = (x + 1j*np.random.rand(size)).astype(self.cdt)
+            y = ifft(fft(x))
+            _assert_close_in_norm(x, y, rtol, size, self.rdt)
+            y = fft(ifft(x))
+            _assert_close_in_norm(x, y, rtol, size, self.rdt)
+
+    def test_invalid_sizes(self):
+        assert_raises(ValueError, ifft, [])
+        assert_raises(ValueError, ifft, [[1,1],[2,2]], -5)
+
+
+class TestDoubleIFFT(_TestIFFTBase):
+    def setup_method(self):
+        self.cdt = np.complex128
+        self.rdt = np.float64
+
+
+class TestSingleIFFT(_TestIFFTBase):
+    def setup_method(self):
+        self.cdt = np.complex64
+        self.rdt = np.float32
+
+
+class _TestRFFTBase:
+    def setup_method(self):
+        np.random.seed(1234)
+
+    def test_definition(self):
+        for t in [[1, 2, 3, 4, 1, 2, 3, 4], [1, 2, 3, 4, 1, 2, 3, 4, 5]]:
+            x = np.array(t, dtype=self.rdt)
+            y = rfft(x)
+            y1 = direct_rdft(x)
+            assert_array_almost_equal(y,y1)
+            assert_equal(y.dtype, self.rdt)
+
+    def test_invalid_sizes(self):
+        assert_raises(ValueError, rfft, [])
+        assert_raises(ValueError, rfft, [[1,1],[2,2]], -5)
+
+    # See gh-5790
+    class MockSeries:
+        def __init__(self, data):
+            self.data = np.asarray(data)
+
+        def __getattr__(self, item):
+            try:
+                return getattr(self.data, item)
+            except AttributeError as e:
+                raise AttributeError("'MockSeries' object "
+                                      f"has no attribute '{item}'") from e
+
+    def test_non_ndarray_with_dtype(self):
+        x = np.array([1., 2., 3., 4., 5.])
+        xs = _TestRFFTBase.MockSeries(x)
+
+        expected = [1, 2, 3, 4, 5]
+        rfft(xs)
+
+        # Data should not have been overwritten
+        assert_equal(x, expected)
+        assert_equal(xs.data, expected)
+
+    def test_complex_input(self):
+        assert_raises(TypeError, rfft, np.arange(4, dtype=np.complex64))
+
+
+class TestRFFTDouble(_TestRFFTBase):
+    def setup_method(self):
+        self.cdt = np.complex128
+        self.rdt = np.float64
+
+
+class TestRFFTSingle(_TestRFFTBase):
+    def setup_method(self):
+        self.cdt = np.complex64
+        self.rdt = np.float32
+
+
+class _TestIRFFTBase:
+    def setup_method(self):
+        np.random.seed(1234)
+
+    def test_definition(self):
+        x1 = [1,2,3,4,1,2,3,4]
+        x1_1 = [1,2+3j,4+1j,2+3j,4,2-3j,4-1j,2-3j]
+        x2 = [1,2,3,4,1,2,3,4,5]
+        x2_1 = [1,2+3j,4+1j,2+3j,4+5j,4-5j,2-3j,4-1j,2-3j]
+
+        def _test(x, xr):
+            y = irfft(np.array(x, dtype=self.rdt))
+            y1 = direct_irdft(x)
+            assert_equal(y.dtype, self.rdt)
+            assert_array_almost_equal(y,y1, decimal=self.ndec)
+            assert_array_almost_equal(y,ifft(xr), decimal=self.ndec)
+
+        _test(x1, x1_1)
+        _test(x2, x2_1)
+
+    def test_random_real(self):
+        for size in [1,51,111,100,200,64,128,256,1024]:
+            x = random([size]).astype(self.rdt)
+            y1 = irfft(rfft(x))
+            y2 = rfft(irfft(x))
+            assert_equal(y1.dtype, self.rdt)
+            assert_equal(y2.dtype, self.rdt)
+            assert_array_almost_equal(y1, x, decimal=self.ndec,
+                                       err_msg="size=%d" % size)
+            assert_array_almost_equal(y2, x, decimal=self.ndec,
+                                       err_msg="size=%d" % size)
+
+    def test_size_accuracy(self):
+        # Sanity check for the accuracy for prime and non-prime sized inputs
+        if self.rdt == np.float32:
+            rtol = 1e-5
+        elif self.rdt == np.float64:
+            rtol = 1e-10
+
+        for size in LARGE_COMPOSITE_SIZES + LARGE_PRIME_SIZES:
+            np.random.seed(1234)
+            x = np.random.rand(size).astype(self.rdt)
+            y = irfft(rfft(x))
+            _assert_close_in_norm(x, y, rtol, size, self.rdt)
+            y = rfft(irfft(x))
+            _assert_close_in_norm(x, y, rtol, size, self.rdt)
+
+    def test_invalid_sizes(self):
+        assert_raises(ValueError, irfft, [])
+        assert_raises(ValueError, irfft, [[1,1],[2,2]], -5)
+
+    def test_complex_input(self):
+        assert_raises(TypeError, irfft, np.arange(4, dtype=np.complex64))
+
+
+# self.ndec is bogus; we should have a assert_array_approx_equal for number of
+# significant digits
+
+class TestIRFFTDouble(_TestIRFFTBase):
+    def setup_method(self):
+        self.cdt = np.complex128
+        self.rdt = np.float64
+        self.ndec = 14
+
+
+class TestIRFFTSingle(_TestIRFFTBase):
+    def setup_method(self):
+        self.cdt = np.complex64
+        self.rdt = np.float32
+        self.ndec = 5
+
+
+class Testfft2:
+    def setup_method(self):
+        np.random.seed(1234)
+
+    def test_regression_244(self):
+        """FFT returns wrong result with axes parameter."""
+        # fftn (and hence fft2) used to break when both axes and shape were
+        # used
+        x = numpy.ones((4, 4, 2))
+        y = fft2(x, shape=(8, 8), axes=(-3, -2))
+        y_r = numpy.fft.fftn(x, s=(8, 8), axes=(-3, -2))
+        assert_array_almost_equal(y, y_r)
+
+    def test_invalid_sizes(self):
+        assert_raises(ValueError, fft2, [[]])
+        assert_raises(ValueError, fft2, [[1, 1], [2, 2]], (4, -3))
+
+
+class TestFftnSingle:
+    def setup_method(self):
+        np.random.seed(1234)
+
+    def test_definition(self):
+        x = [[1, 2, 3],
+             [4, 5, 6],
+             [7, 8, 9]]
+        y = fftn(np.array(x, np.float32))
+        assert_(y.dtype == np.complex64,
+                msg="double precision output with single precision")
+
+        y_r = np.array(fftn(x), np.complex64)
+        assert_array_almost_equal_nulp(y, y_r)
+
+    @pytest.mark.parametrize('size', SMALL_COMPOSITE_SIZES + SMALL_PRIME_SIZES)
+    def test_size_accuracy_small(self, size):
+        x = np.random.rand(size, size) + 1j*np.random.rand(size, size)
+        y1 = fftn(x.real.astype(np.float32))
+        y2 = fftn(x.real.astype(np.float64)).astype(np.complex64)
+
+        assert_equal(y1.dtype, np.complex64)
+        assert_array_almost_equal_nulp(y1, y2, 2000)
+
+    @pytest.mark.parametrize('size', LARGE_COMPOSITE_SIZES + LARGE_PRIME_SIZES)
+    def test_size_accuracy_large(self, size):
+        x = np.random.rand(size, 3) + 1j*np.random.rand(size, 3)
+        y1 = fftn(x.real.astype(np.float32))
+        y2 = fftn(x.real.astype(np.float64)).astype(np.complex64)
+
+        assert_equal(y1.dtype, np.complex64)
+        assert_array_almost_equal_nulp(y1, y2, 2000)
+
+    def test_definition_float16(self):
+        x = [[1, 2, 3],
+             [4, 5, 6],
+             [7, 8, 9]]
+        y = fftn(np.array(x, np.float16))
+        assert_equal(y.dtype, np.complex64)
+        y_r = np.array(fftn(x), np.complex64)
+        assert_array_almost_equal_nulp(y, y_r)
+
+    @pytest.mark.parametrize('size', SMALL_COMPOSITE_SIZES + SMALL_PRIME_SIZES)
+    def test_float16_input_small(self, size):
+        x = np.random.rand(size, size) + 1j*np.random.rand(size, size)
+        y1 = fftn(x.real.astype(np.float16))
+        y2 = fftn(x.real.astype(np.float64)).astype(np.complex64)
+
+        assert_equal(y1.dtype, np.complex64)
+        assert_array_almost_equal_nulp(y1, y2, 5e5)
+
+    @pytest.mark.parametrize('size', LARGE_COMPOSITE_SIZES + LARGE_PRIME_SIZES)
+    def test_float16_input_large(self, size):
+        x = np.random.rand(size, 3) + 1j*np.random.rand(size, 3)
+        y1 = fftn(x.real.astype(np.float16))
+        y2 = fftn(x.real.astype(np.float64)).astype(np.complex64)
+
+        assert_equal(y1.dtype, np.complex64)
+        assert_array_almost_equal_nulp(y1, y2, 2e6)
+
+
+class TestFftn:
+    def setup_method(self):
+        np.random.seed(1234)
+
+    def test_definition(self):
+        x = [[1, 2, 3],
+             [4, 5, 6],
+             [7, 8, 9]]
+        y = fftn(x)
+        assert_array_almost_equal(y, direct_dftn(x))
+
+        x = random((20, 26))
+        assert_array_almost_equal(fftn(x), direct_dftn(x))
+
+        x = random((5, 4, 3, 20))
+        assert_array_almost_equal(fftn(x), direct_dftn(x))
+
+    def test_axes_argument(self):
+        # plane == ji_plane, x== kji_space
+        plane1 = [[1, 2, 3],
+                  [4, 5, 6],
+                  [7, 8, 9]]
+        plane2 = [[10, 11, 12],
+                  [13, 14, 15],
+                  [16, 17, 18]]
+        plane3 = [[19, 20, 21],
+                  [22, 23, 24],
+                  [25, 26, 27]]
+        ki_plane1 = [[1, 2, 3],
+                     [10, 11, 12],
+                     [19, 20, 21]]
+        ki_plane2 = [[4, 5, 6],
+                     [13, 14, 15],
+                     [22, 23, 24]]
+        ki_plane3 = [[7, 8, 9],
+                     [16, 17, 18],
+                     [25, 26, 27]]
+        jk_plane1 = [[1, 10, 19],
+                     [4, 13, 22],
+                     [7, 16, 25]]
+        jk_plane2 = [[2, 11, 20],
+                     [5, 14, 23],
+                     [8, 17, 26]]
+        jk_plane3 = [[3, 12, 21],
+                     [6, 15, 24],
+                     [9, 18, 27]]
+        kj_plane1 = [[1, 4, 7],
+                     [10, 13, 16], [19, 22, 25]]
+        kj_plane2 = [[2, 5, 8],
+                     [11, 14, 17], [20, 23, 26]]
+        kj_plane3 = [[3, 6, 9],
+                     [12, 15, 18], [21, 24, 27]]
+        ij_plane1 = [[1, 4, 7],
+                     [2, 5, 8],
+                     [3, 6, 9]]
+        ij_plane2 = [[10, 13, 16],
+                     [11, 14, 17],
+                     [12, 15, 18]]
+        ij_plane3 = [[19, 22, 25],
+                     [20, 23, 26],
+                     [21, 24, 27]]
+        ik_plane1 = [[1, 10, 19],
+                     [2, 11, 20],
+                     [3, 12, 21]]
+        ik_plane2 = [[4, 13, 22],
+                     [5, 14, 23],
+                     [6, 15, 24]]
+        ik_plane3 = [[7, 16, 25],
+                     [8, 17, 26],
+                     [9, 18, 27]]
+        ijk_space = [jk_plane1, jk_plane2, jk_plane3]
+        ikj_space = [kj_plane1, kj_plane2, kj_plane3]
+        jik_space = [ik_plane1, ik_plane2, ik_plane3]
+        jki_space = [ki_plane1, ki_plane2, ki_plane3]
+        kij_space = [ij_plane1, ij_plane2, ij_plane3]
+        x = array([plane1, plane2, plane3])
+
+        assert_array_almost_equal(fftn(x),
+                                  fftn(x, axes=(-3, -2, -1)))  # kji_space
+        assert_array_almost_equal(fftn(x), fftn(x, axes=(0, 1, 2)))
+        assert_array_almost_equal(fftn(x, axes=(0, 2)), fftn(x, axes=(0, -1)))
+        y = fftn(x, axes=(2, 1, 0))  # ijk_space
+        assert_array_almost_equal(swapaxes(y, -1, -3), fftn(ijk_space))
+        y = fftn(x, axes=(2, 0, 1))  # ikj_space
+        assert_array_almost_equal(swapaxes(swapaxes(y, -1, -3), -1, -2),
+                                  fftn(ikj_space))
+        y = fftn(x, axes=(1, 2, 0))  # jik_space
+        assert_array_almost_equal(swapaxes(swapaxes(y, -1, -3), -3, -2),
+                                  fftn(jik_space))
+        y = fftn(x, axes=(1, 0, 2))  # jki_space
+        assert_array_almost_equal(swapaxes(y, -2, -3), fftn(jki_space))
+        y = fftn(x, axes=(0, 2, 1))  # kij_space
+        assert_array_almost_equal(swapaxes(y, -2, -1), fftn(kij_space))
+
+        y = fftn(x, axes=(-2, -1))  # ji_plane
+        assert_array_almost_equal(fftn(plane1), y[0])
+        assert_array_almost_equal(fftn(plane2), y[1])
+        assert_array_almost_equal(fftn(plane3), y[2])
+
+        y = fftn(x, axes=(1, 2))  # ji_plane
+        assert_array_almost_equal(fftn(plane1), y[0])
+        assert_array_almost_equal(fftn(plane2), y[1])
+        assert_array_almost_equal(fftn(plane3), y[2])
+
+        y = fftn(x, axes=(-3, -2))  # kj_plane
+        assert_array_almost_equal(fftn(x[:, :, 0]), y[:, :, 0])
+        assert_array_almost_equal(fftn(x[:, :, 1]), y[:, :, 1])
+        assert_array_almost_equal(fftn(x[:, :, 2]), y[:, :, 2])
+
+        y = fftn(x, axes=(-3, -1))  # ki_plane
+        assert_array_almost_equal(fftn(x[:, 0, :]), y[:, 0, :])
+        assert_array_almost_equal(fftn(x[:, 1, :]), y[:, 1, :])
+        assert_array_almost_equal(fftn(x[:, 2, :]), y[:, 2, :])
+
+        y = fftn(x, axes=(-1, -2))  # ij_plane
+        assert_array_almost_equal(fftn(ij_plane1), swapaxes(y[0], -2, -1))
+        assert_array_almost_equal(fftn(ij_plane2), swapaxes(y[1], -2, -1))
+        assert_array_almost_equal(fftn(ij_plane3), swapaxes(y[2], -2, -1))
+
+        y = fftn(x, axes=(-1, -3))  # ik_plane
+        assert_array_almost_equal(fftn(ik_plane1),
+                                  swapaxes(y[:, 0, :], -1, -2))
+        assert_array_almost_equal(fftn(ik_plane2),
+                                  swapaxes(y[:, 1, :], -1, -2))
+        assert_array_almost_equal(fftn(ik_plane3),
+                                  swapaxes(y[:, 2, :], -1, -2))
+
+        y = fftn(x, axes=(-2, -3))  # jk_plane
+        assert_array_almost_equal(fftn(jk_plane1),
+                                  swapaxes(y[:, :, 0], -1, -2))
+        assert_array_almost_equal(fftn(jk_plane2),
+                                  swapaxes(y[:, :, 1], -1, -2))
+        assert_array_almost_equal(fftn(jk_plane3),
+                                  swapaxes(y[:, :, 2], -1, -2))
+
+        y = fftn(x, axes=(-1,))  # i_line
+        for i in range(3):
+            for j in range(3):
+                assert_array_almost_equal(fft(x[i, j, :]), y[i, j, :])
+        y = fftn(x, axes=(-2,))  # j_line
+        for i in range(3):
+            for j in range(3):
+                assert_array_almost_equal(fft(x[i, :, j]), y[i, :, j])
+        y = fftn(x, axes=(0,))  # k_line
+        for i in range(3):
+            for j in range(3):
+                assert_array_almost_equal(fft(x[:, i, j]), y[:, i, j])
+
+        y = fftn(x, axes=())  # point
+        assert_array_almost_equal(y, x)
+
+    def test_shape_argument(self):
+        small_x = [[1, 2, 3],
+                   [4, 5, 6]]
+        large_x1 = [[1, 2, 3, 0],
+                    [4, 5, 6, 0],
+                    [0, 0, 0, 0],
+                    [0, 0, 0, 0]]
+
+        y = fftn(small_x, shape=(4, 4))
+        assert_array_almost_equal(y, fftn(large_x1))
+
+        y = fftn(small_x, shape=(3, 4))
+        assert_array_almost_equal(y, fftn(large_x1[:-1]))
+
+    def test_shape_axes_argument(self):
+        small_x = [[1, 2, 3],
+                   [4, 5, 6],
+                   [7, 8, 9]]
+        large_x1 = array([[1, 2, 3, 0],
+                          [4, 5, 6, 0],
+                          [7, 8, 9, 0],
+                          [0, 0, 0, 0]])
+        y = fftn(small_x, shape=(4, 4), axes=(-2, -1))
+        assert_array_almost_equal(y, fftn(large_x1))
+        y = fftn(small_x, shape=(4, 4), axes=(-1, -2))
+
+        assert_array_almost_equal(y, swapaxes(
+            fftn(swapaxes(large_x1, -1, -2)), -1, -2))
+
+    def test_shape_axes_argument2(self):
+        # Change shape of the last axis
+        x = numpy.random.random((10, 5, 3, 7))
+        y = fftn(x, axes=(-1,), shape=(8,))
+        assert_array_almost_equal(y, fft(x, axis=-1, n=8))
+
+        # Change shape of an arbitrary axis which is not the last one
+        x = numpy.random.random((10, 5, 3, 7))
+        y = fftn(x, axes=(-2,), shape=(8,))
+        assert_array_almost_equal(y, fft(x, axis=-2, n=8))
+
+        # Change shape of axes: cf #244, where shape and axes were mixed up
+        x = numpy.random.random((4, 4, 2))
+        y = fftn(x, axes=(-3, -2), shape=(8, 8))
+        assert_array_almost_equal(y,
+                                  numpy.fft.fftn(x, axes=(-3, -2), s=(8, 8)))
+
+    def test_shape_argument_more(self):
+        x = zeros((4, 4, 2))
+        with assert_raises(ValueError,
+                           match="when given, axes and shape arguments"
+                           " have to be of the same length"):
+            fftn(x, shape=(8, 8, 2, 1))
+
+    def test_invalid_sizes(self):
+        with assert_raises(ValueError,
+                           match="invalid number of data points"
+                           r" \(\[1, 0\]\) specified"):
+            fftn([[]])
+
+        with assert_raises(ValueError,
+                           match="invalid number of data points"
+                           r" \(\[4, -3\]\) specified"):
+            fftn([[1, 1], [2, 2]], (4, -3))
+
+
+class TestIfftn:
+    dtype = None
+    cdtype = None
+
+    def setup_method(self):
+        np.random.seed(1234)
+
+    @pytest.mark.parametrize('dtype,cdtype,maxnlp',
+                             [(np.float64, np.complex128, 2000),
+                              (np.float32, np.complex64, 3500)])
+    def test_definition(self, dtype, cdtype, maxnlp):
+        x = np.array([[1, 2, 3],
+                      [4, 5, 6],
+                      [7, 8, 9]], dtype=dtype)
+        y = ifftn(x)
+        assert_equal(y.dtype, cdtype)
+        assert_array_almost_equal_nulp(y, direct_idftn(x), maxnlp)
+
+        x = random((20, 26))
+        assert_array_almost_equal_nulp(ifftn(x), direct_idftn(x), maxnlp)
+
+        x = random((5, 4, 3, 20))
+        assert_array_almost_equal_nulp(ifftn(x), direct_idftn(x), maxnlp)
+
+    @pytest.mark.parametrize('maxnlp', [2000, 3500])
+    @pytest.mark.parametrize('size', [1, 2, 51, 32, 64, 92])
+    def test_random_complex(self, maxnlp, size):
+        x = random([size, size]) + 1j*random([size, size])
+        assert_array_almost_equal_nulp(ifftn(fftn(x)), x, maxnlp)
+        assert_array_almost_equal_nulp(fftn(ifftn(x)), x, maxnlp)
+
+    def test_invalid_sizes(self):
+        with assert_raises(ValueError,
+                           match="invalid number of data points"
+                           r" \(\[1, 0\]\) specified"):
+            ifftn([[]])
+
+        with assert_raises(ValueError,
+                           match="invalid number of data points"
+                           r" \(\[4, -3\]\) specified"):
+            ifftn([[1, 1], [2, 2]], (4, -3))
+
+
+class FakeArray:
+    def __init__(self, data):
+        self._data = data
+        self.__array_interface__ = data.__array_interface__
+
+
+class FakeArray2:
+    def __init__(self, data):
+        self._data = data
+
+    def __array__(self, dtype=None, copy=None):
+        return self._data
+
+
+class TestOverwrite:
+    """Check input overwrite behavior of the FFT functions."""
+
+    real_dtypes = (np.float32, np.float64)
+    dtypes = real_dtypes + (np.complex64, np.complex128)
+    fftsizes = [8, 16, 32]
+
+    def _check(self, x, routine, fftsize, axis, overwrite_x):
+        x2 = x.copy()
+        for fake in [lambda x: x, FakeArray, FakeArray2]:
+            routine(fake(x2), fftsize, axis, overwrite_x=overwrite_x)
+
+            sig = "{}({}{!r}, {!r}, axis={!r}, overwrite_x={!r})".format(
+                routine.__name__, x.dtype, x.shape, fftsize, axis, overwrite_x)
+            if not overwrite_x:
+                assert_equal(x2, x, err_msg="spurious overwrite in %s" % sig)
+
+    def _check_1d(self, routine, dtype, shape, axis, overwritable_dtypes,
+                  fftsize, overwrite_x):
+        np.random.seed(1234)
+        if np.issubdtype(dtype, np.complexfloating):
+            data = np.random.randn(*shape) + 1j*np.random.randn(*shape)
+        else:
+            data = np.random.randn(*shape)
+        data = data.astype(dtype)
+
+        self._check(data, routine, fftsize, axis,
+                    overwrite_x=overwrite_x)
+
+    @pytest.mark.parametrize('dtype', dtypes)
+    @pytest.mark.parametrize('fftsize', fftsizes)
+    @pytest.mark.parametrize('overwrite_x', [True, False])
+    @pytest.mark.parametrize('shape,axes', [((16,), -1),
+                                            ((16, 2), 0),
+                                            ((2, 16), 1)])
+    def test_fft_ifft(self, dtype, fftsize, overwrite_x, shape, axes):
+        overwritable = (np.complex128, np.complex64)
+        self._check_1d(fft, dtype, shape, axes, overwritable,
+                       fftsize, overwrite_x)
+        self._check_1d(ifft, dtype, shape, axes, overwritable,
+                       fftsize, overwrite_x)
+
+    @pytest.mark.parametrize('dtype', real_dtypes)
+    @pytest.mark.parametrize('fftsize', fftsizes)
+    @pytest.mark.parametrize('overwrite_x', [True, False])
+    @pytest.mark.parametrize('shape,axes', [((16,), -1),
+                                            ((16, 2), 0),
+                                            ((2, 16), 1)])
+    def test_rfft_irfft(self, dtype, fftsize, overwrite_x, shape, axes):
+        overwritable = self.real_dtypes
+        self._check_1d(irfft, dtype, shape, axes, overwritable,
+                       fftsize, overwrite_x)
+        self._check_1d(rfft, dtype, shape, axes, overwritable,
+                       fftsize, overwrite_x)
+
+    def _check_nd_one(self, routine, dtype, shape, axes, overwritable_dtypes,
+                      overwrite_x):
+        np.random.seed(1234)
+        if np.issubdtype(dtype, np.complexfloating):
+            data = np.random.randn(*shape) + 1j*np.random.randn(*shape)
+        else:
+            data = np.random.randn(*shape)
+        data = data.astype(dtype)
+
+        def fftshape_iter(shp):
+            if len(shp) <= 0:
+                yield ()
+            else:
+                for j in (shp[0]//2, shp[0], shp[0]*2):
+                    for rest in fftshape_iter(shp[1:]):
+                        yield (j,) + rest
+
+        if axes is None:
+            part_shape = shape
+        else:
+            part_shape = tuple(np.take(shape, axes))
+
+        for fftshape in fftshape_iter(part_shape):
+            self._check(data, routine, fftshape, axes,
+                        overwrite_x=overwrite_x)
+            if data.ndim > 1:
+                self._check(data.T, routine, fftshape, axes,
+                            overwrite_x=overwrite_x)
+
+    @pytest.mark.parametrize('dtype', dtypes)
+    @pytest.mark.parametrize('overwrite_x', [True, False])
+    @pytest.mark.parametrize('shape,axes', [((16,), None),
+                                            ((16,), (0,)),
+                                            ((16, 2), (0,)),
+                                            ((2, 16), (1,)),
+                                            ((8, 16), None),
+                                            ((8, 16), (0, 1)),
+                                            ((8, 16, 2), (0, 1)),
+                                            ((8, 16, 2), (1, 2)),
+                                            ((8, 16, 2), (0,)),
+                                            ((8, 16, 2), (1,)),
+                                            ((8, 16, 2), (2,)),
+                                            ((8, 16, 2), None),
+                                            ((8, 16, 2), (0, 1, 2))])
+    def test_fftn_ifftn(self, dtype, overwrite_x, shape, axes):
+        overwritable = (np.complex128, np.complex64)
+        self._check_nd_one(fftn, dtype, shape, axes, overwritable,
+                           overwrite_x)
+        self._check_nd_one(ifftn, dtype, shape, axes, overwritable,
+                           overwrite_x)
+
+
+@pytest.mark.parametrize('func', [fftn, ifftn, fft2])
+def test_shape_axes_ndarray(func):
+    # Test fftn and ifftn work with NumPy arrays for shape and axes arguments
+    # Regression test for gh-13342
+    a = np.random.rand(10, 10)
+
+    expect = func(a, shape=(5, 5))
+    actual = func(a, shape=np.array([5, 5]))
+    assert_equal(expect, actual)
+
+    expect = func(a, axes=(-1,))
+    actual = func(a, axes=np.array([-1,]))
+    assert_equal(expect, actual)
+
+    expect = func(a, shape=(4, 7), axes=(1, 0))
+    actual = func(a, shape=np.array([4, 7]), axes=np.array([1, 0]))
+    assert_equal(expect, actual)

venv/lib/python3.12/site-packages/scipy/fftpack/tests/test_helper.py

@@ -0,0 +1,54 @@
+# Created by Pearu Peterson, September 2002
+
+__usage__ = """
+Build fftpack:
+  python setup_fftpack.py build
+Run tests if scipy is installed:
+  python -c 'import scipy;scipy.fftpack.test(<level>)'
+Run tests if fftpack is not installed:
+  python tests/test_helper.py [<level>]
+"""
+
+from numpy.testing import assert_array_almost_equal
+from scipy.fftpack import fftshift, ifftshift, fftfreq, rfftfreq
+
+from numpy import pi, random
+
+class TestFFTShift:
+
+    def test_definition(self):
+        x = [0,1,2,3,4,-4,-3,-2,-1]
+        y = [-4,-3,-2,-1,0,1,2,3,4]
+        assert_array_almost_equal(fftshift(x),y)
+        assert_array_almost_equal(ifftshift(y),x)
+        x = [0,1,2,3,4,-5,-4,-3,-2,-1]
+        y = [-5,-4,-3,-2,-1,0,1,2,3,4]
+        assert_array_almost_equal(fftshift(x),y)
+        assert_array_almost_equal(ifftshift(y),x)
+
+    def test_inverse(self):
+        for n in [1,4,9,100,211]:
+            x = random.random((n,))
+            assert_array_almost_equal(ifftshift(fftshift(x)),x)
+
+
+class TestFFTFreq:
+
+    def test_definition(self):
+        x = [0,1,2,3,4,-4,-3,-2,-1]
+        assert_array_almost_equal(9*fftfreq(9),x)
+        assert_array_almost_equal(9*pi*fftfreq(9,pi),x)
+        x = [0,1,2,3,4,-5,-4,-3,-2,-1]
+        assert_array_almost_equal(10*fftfreq(10),x)
+        assert_array_almost_equal(10*pi*fftfreq(10,pi),x)
+
+
+class TestRFFTFreq:
+
+    def test_definition(self):
+        x = [0,1,1,2,2,3,3,4,4]
+        assert_array_almost_equal(9*rfftfreq(9),x)
+        assert_array_almost_equal(9*pi*rfftfreq(9,pi),x)
+        x = [0,1,1,2,2,3,3,4,4,5]
+        assert_array_almost_equal(10*rfftfreq(10),x)
+        assert_array_almost_equal(10*pi*rfftfreq(10,pi),x)

venv/lib/python3.12/site-packages/scipy/fftpack/tests/test_import.py

@@ -0,0 +1,33 @@
+"""Test possibility of patching fftpack with pyfftw.
+
+No module source outside of scipy.fftpack should contain an import of
+the form `from scipy.fftpack import ...`, so that a simple replacement
+of scipy.fftpack by the corresponding fftw interface completely swaps
+the two FFT implementations.
+
+Because this simply inspects source files, we only need to run the test
+on one version of Python.
+"""
+
+
+from pathlib import Path
+import re
+import tokenize
+import pytest
+from numpy.testing import assert_
+import scipy
+
+class TestFFTPackImport:
+    @pytest.mark.slow
+    def test_fftpack_import(self):
+        base = Path(scipy.__file__).parent
+        regexp = r"\s*from.+\.fftpack import .*\n"
+        for path in base.rglob("*.py"):
+            if base / "fftpack" in path.parents:
+                continue
+            # use tokenize to auto-detect encoding on systems where no
+            # default encoding is defined (e.g., LANG='C')
+            with tokenize.open(str(path)) as file:
+                assert_(all(not re.fullmatch(regexp, line)
+                            for line in file),
+                        f"{path} contains an import from fftpack")

venv/lib/python3.12/site-packages/scipy/fftpack/tests/test_pseudo_diffs.py

@@ -0,0 +1,380 @@
+# Created by Pearu Peterson, September 2002
+
+__usage__ = """
+Build fftpack:
+  python setup_fftpack.py build
+Run tests if scipy is installed:
+  python -c 'import scipy;scipy.fftpack.test(<level>)'
+Run tests if fftpack is not installed:
+  python tests/test_pseudo_diffs.py [<level>]
+"""
+
+from numpy.testing import (assert_equal, assert_almost_equal,
+                           assert_array_almost_equal)
+from scipy.fftpack import (diff, fft, ifft, tilbert, itilbert, hilbert,
+                           ihilbert, shift, fftfreq, cs_diff, sc_diff,
+                           ss_diff, cc_diff)
+
+import numpy as np
+from numpy import arange, sin, cos, pi, exp, tanh, sum, sign
+from numpy.random import random
+
+
+def direct_diff(x,k=1,period=None):
+    fx = fft(x)
+    n = len(fx)
+    if period is None:
+        period = 2*pi
+    w = fftfreq(n)*2j*pi/period*n
+    if k < 0:
+        w = 1 / w**k
+        w[0] = 0.0
+    else:
+        w = w**k
+    if n > 2000:
+        w[250:n-250] = 0.0
+    return ifft(w*fx).real
+
+
+def direct_tilbert(x,h=1,period=None):
+    fx = fft(x)
+    n = len(fx)
+    if period is None:
+        period = 2*pi
+    w = fftfreq(n)*h*2*pi/period*n
+    w[0] = 1
+    w = 1j/tanh(w)
+    w[0] = 0j
+    return ifft(w*fx)
+
+
+def direct_itilbert(x,h=1,period=None):
+    fx = fft(x)
+    n = len(fx)
+    if period is None:
+        period = 2*pi
+    w = fftfreq(n)*h*2*pi/period*n
+    w = -1j*tanh(w)
+    return ifft(w*fx)
+
+
+def direct_hilbert(x):
+    fx = fft(x)
+    n = len(fx)
+    w = fftfreq(n)*n
+    w = 1j*sign(w)
+    return ifft(w*fx)
+
+
+def direct_ihilbert(x):
+    return -direct_hilbert(x)
+
+
+def direct_shift(x,a,period=None):
+    n = len(x)
+    if period is None:
+        k = fftfreq(n)*1j*n
+    else:
+        k = fftfreq(n)*2j*pi/period*n
+    return ifft(fft(x)*exp(k*a)).real
+
+
+class TestDiff:
+
+    def test_definition(self):
+        for n in [16,17,64,127,32]:
+            x = arange(n)*2*pi/n
+            assert_array_almost_equal(diff(sin(x)),direct_diff(sin(x)))
+            assert_array_almost_equal(diff(sin(x),2),direct_diff(sin(x),2))
+            assert_array_almost_equal(diff(sin(x),3),direct_diff(sin(x),3))
+            assert_array_almost_equal(diff(sin(x),4),direct_diff(sin(x),4))
+            assert_array_almost_equal(diff(sin(x),5),direct_diff(sin(x),5))
+            assert_array_almost_equal(diff(sin(2*x),3),direct_diff(sin(2*x),3))
+            assert_array_almost_equal(diff(sin(2*x),4),direct_diff(sin(2*x),4))
+            assert_array_almost_equal(diff(cos(x)),direct_diff(cos(x)))
+            assert_array_almost_equal(diff(cos(x),2),direct_diff(cos(x),2))
+            assert_array_almost_equal(diff(cos(x),3),direct_diff(cos(x),3))
+            assert_array_almost_equal(diff(cos(x),4),direct_diff(cos(x),4))
+            assert_array_almost_equal(diff(cos(2*x)),direct_diff(cos(2*x)))
+            assert_array_almost_equal(diff(sin(x*n/8)),direct_diff(sin(x*n/8)))
+            assert_array_almost_equal(diff(cos(x*n/8)),direct_diff(cos(x*n/8)))
+            for k in range(5):
+                assert_array_almost_equal(diff(sin(4*x),k),direct_diff(sin(4*x),k))
+                assert_array_almost_equal(diff(cos(4*x),k),direct_diff(cos(4*x),k))
+
+    def test_period(self):
+        for n in [17,64]:
+            x = arange(n)/float(n)
+            assert_array_almost_equal(diff(sin(2*pi*x),period=1),
+                                      2*pi*cos(2*pi*x))
+            assert_array_almost_equal(diff(sin(2*pi*x),3,period=1),
+                                      -(2*pi)**3*cos(2*pi*x))
+
+    def test_sin(self):
+        for n in [32,64,77]:
+            x = arange(n)*2*pi/n
+            assert_array_almost_equal(diff(sin(x)),cos(x))
+            assert_array_almost_equal(diff(cos(x)),-sin(x))
+            assert_array_almost_equal(diff(sin(x),2),-sin(x))
+            assert_array_almost_equal(diff(sin(x),4),sin(x))
+            assert_array_almost_equal(diff(sin(4*x)),4*cos(4*x))
+            assert_array_almost_equal(diff(sin(sin(x))),cos(x)*cos(sin(x)))
+
+    def test_expr(self):
+        for n in [64,77,100,128,256,512,1024,2048,4096,8192][:5]:
+            x = arange(n)*2*pi/n
+            f = sin(x)*cos(4*x)+exp(sin(3*x))
+            df = cos(x)*cos(4*x)-4*sin(x)*sin(4*x)+3*cos(3*x)*exp(sin(3*x))
+            ddf = -17*sin(x)*cos(4*x)-8*cos(x)*sin(4*x)\
+                 - 9*sin(3*x)*exp(sin(3*x))+9*cos(3*x)**2*exp(sin(3*x))
+            d1 = diff(f)
+            assert_array_almost_equal(d1,df)
+            assert_array_almost_equal(diff(df),ddf)
+            assert_array_almost_equal(diff(f,2),ddf)
+            assert_array_almost_equal(diff(ddf,-1),df)
+
+    def test_expr_large(self):
+        for n in [2048,4096]:
+            x = arange(n)*2*pi/n
+            f = sin(x)*cos(4*x)+exp(sin(3*x))
+            df = cos(x)*cos(4*x)-4*sin(x)*sin(4*x)+3*cos(3*x)*exp(sin(3*x))
+            ddf = -17*sin(x)*cos(4*x)-8*cos(x)*sin(4*x)\
+                 - 9*sin(3*x)*exp(sin(3*x))+9*cos(3*x)**2*exp(sin(3*x))
+            assert_array_almost_equal(diff(f),df)
+            assert_array_almost_equal(diff(df),ddf)
+            assert_array_almost_equal(diff(ddf,-1),df)
+            assert_array_almost_equal(diff(f,2),ddf)
+
+    def test_int(self):
+        n = 64
+        x = arange(n)*2*pi/n
+        assert_array_almost_equal(diff(sin(x),-1),-cos(x))
+        assert_array_almost_equal(diff(sin(x),-2),-sin(x))
+        assert_array_almost_equal(diff(sin(x),-4),sin(x))
+        assert_array_almost_equal(diff(2*cos(2*x),-1),sin(2*x))
+
+    def test_random_even(self):
+        for k in [0,2,4,6]:
+            for n in [60,32,64,56,55]:
+                f = random((n,))
+                af = sum(f,axis=0)/n
+                f = f-af
+                # zeroing Nyquist mode:
+                f = diff(diff(f,1),-1)
+                assert_almost_equal(sum(f,axis=0),0.0)
+                assert_array_almost_equal(diff(diff(f,k),-k),f)
+                assert_array_almost_equal(diff(diff(f,-k),k),f)
+
+    def test_random_odd(self):
+        for k in [0,1,2,3,4,5,6]:
+            for n in [33,65,55]:
+                f = random((n,))
+                af = sum(f,axis=0)/n
+                f = f-af
+                assert_almost_equal(sum(f,axis=0),0.0)
+                assert_array_almost_equal(diff(diff(f,k),-k),f)
+                assert_array_almost_equal(diff(diff(f,-k),k),f)
+
+    def test_zero_nyquist(self):
+        for k in [0,1,2,3,4,5,6]:
+            for n in [32,33,64,56,55]:
+                f = random((n,))
+                af = sum(f,axis=0)/n
+                f = f-af
+                # zeroing Nyquist mode:
+                f = diff(diff(f,1),-1)
+                assert_almost_equal(sum(f,axis=0),0.0)
+                assert_array_almost_equal(diff(diff(f,k),-k),f)
+                assert_array_almost_equal(diff(diff(f,-k),k),f)
+
+
+class TestTilbert:
+
+    def test_definition(self):
+        for h in [0.1,0.5,1,5.5,10]:
+            for n in [16,17,64,127]:
+                x = arange(n)*2*pi/n
+                y = tilbert(sin(x),h)
+                y1 = direct_tilbert(sin(x),h)
+                assert_array_almost_equal(y,y1)
+                assert_array_almost_equal(tilbert(sin(x),h),
+                                          direct_tilbert(sin(x),h))
+                assert_array_almost_equal(tilbert(sin(2*x),h),
+                                          direct_tilbert(sin(2*x),h))
+
+    def test_random_even(self):
+        for h in [0.1,0.5,1,5.5,10]:
+            for n in [32,64,56]:
+                f = random((n,))
+                af = sum(f,axis=0)/n
+                f = f-af
+                assert_almost_equal(sum(f,axis=0),0.0)
+                assert_array_almost_equal(direct_tilbert(direct_itilbert(f,h),h),f)
+
+    def test_random_odd(self):
+        for h in [0.1,0.5,1,5.5,10]:
+            for n in [33,65,55]:
+                f = random((n,))
+                af = sum(f,axis=0)/n
+                f = f-af
+                assert_almost_equal(sum(f,axis=0),0.0)
+                assert_array_almost_equal(itilbert(tilbert(f,h),h),f)
+                assert_array_almost_equal(tilbert(itilbert(f,h),h),f)
+
+
+class TestITilbert:
+
+    def test_definition(self):
+        for h in [0.1,0.5,1,5.5,10]:
+            for n in [16,17,64,127]:
+                x = arange(n)*2*pi/n
+                y = itilbert(sin(x),h)
+                y1 = direct_itilbert(sin(x),h)
+                assert_array_almost_equal(y,y1)
+                assert_array_almost_equal(itilbert(sin(x),h),
+                                          direct_itilbert(sin(x),h))
+                assert_array_almost_equal(itilbert(sin(2*x),h),
+                                          direct_itilbert(sin(2*x),h))
+
+
+class TestHilbert:
+
+    def test_definition(self):
+        for n in [16,17,64,127]:
+            x = arange(n)*2*pi/n
+            y = hilbert(sin(x))
+            y1 = direct_hilbert(sin(x))
+            assert_array_almost_equal(y,y1)
+            assert_array_almost_equal(hilbert(sin(2*x)),
+                                      direct_hilbert(sin(2*x)))
+
+    def test_tilbert_relation(self):
+        for n in [16,17,64,127]:
+            x = arange(n)*2*pi/n
+            f = sin(x)+cos(2*x)*sin(x)
+            y = hilbert(f)
+            y1 = direct_hilbert(f)
+            assert_array_almost_equal(y,y1)
+            y2 = tilbert(f,h=10)
+            assert_array_almost_equal(y,y2)
+
+    def test_random_odd(self):
+        for n in [33,65,55]:
+            f = random((n,))
+            af = sum(f,axis=0)/n
+            f = f-af
+            assert_almost_equal(sum(f,axis=0),0.0)
+            assert_array_almost_equal(ihilbert(hilbert(f)),f)
+            assert_array_almost_equal(hilbert(ihilbert(f)),f)
+
+    def test_random_even(self):
+        for n in [32,64,56]:
+            f = random((n,))
+            af = sum(f,axis=0)/n
+            f = f-af
+            # zeroing Nyquist mode:
+            f = diff(diff(f,1),-1)
+            assert_almost_equal(sum(f,axis=0),0.0)
+            assert_array_almost_equal(direct_hilbert(direct_ihilbert(f)),f)
+            assert_array_almost_equal(hilbert(ihilbert(f)),f)
+
+
+class TestIHilbert:
+
+    def test_definition(self):
+        for n in [16,17,64,127]:
+            x = arange(n)*2*pi/n
+            y = ihilbert(sin(x))
+            y1 = direct_ihilbert(sin(x))
+            assert_array_almost_equal(y,y1)
+            assert_array_almost_equal(ihilbert(sin(2*x)),
+                                      direct_ihilbert(sin(2*x)))
+
+    def test_itilbert_relation(self):
+        for n in [16,17,64,127]:
+            x = arange(n)*2*pi/n
+            f = sin(x)+cos(2*x)*sin(x)
+            y = ihilbert(f)
+            y1 = direct_ihilbert(f)
+            assert_array_almost_equal(y,y1)
+            y2 = itilbert(f,h=10)
+            assert_array_almost_equal(y,y2)
+
+
+class TestShift:
+
+    def test_definition(self):
+        for n in [18,17,64,127,32,2048,256]:
+            x = arange(n)*2*pi/n
+            for a in [0.1,3]:
+                assert_array_almost_equal(shift(sin(x),a),direct_shift(sin(x),a))
+                assert_array_almost_equal(shift(sin(x),a),sin(x+a))
+                assert_array_almost_equal(shift(cos(x),a),cos(x+a))
+                assert_array_almost_equal(shift(cos(2*x)+sin(x),a),
+                                          cos(2*(x+a))+sin(x+a))
+                assert_array_almost_equal(shift(exp(sin(x)),a),exp(sin(x+a)))
+            assert_array_almost_equal(shift(sin(x),2*pi),sin(x))
+            assert_array_almost_equal(shift(sin(x),pi),-sin(x))
+            assert_array_almost_equal(shift(sin(x),pi/2),cos(x))
+
+
+class TestOverwrite:
+    """Check input overwrite behavior """
+
+    real_dtypes = (np.float32, np.float64)
+    dtypes = real_dtypes + (np.complex64, np.complex128)
+
+    def _check(self, x, routine, *args, **kwargs):
+        x2 = x.copy()
+        routine(x2, *args, **kwargs)
+        sig = routine.__name__
+        if args:
+            sig += repr(args)
+        if kwargs:
+            sig += repr(kwargs)
+        assert_equal(x2, x, err_msg="spurious overwrite in %s" % sig)
+
+    def _check_1d(self, routine, dtype, shape, *args, **kwargs):
+        np.random.seed(1234)
+        if np.issubdtype(dtype, np.complexfloating):
+            data = np.random.randn(*shape) + 1j*np.random.randn(*shape)
+        else:
+            data = np.random.randn(*shape)
+        data = data.astype(dtype)
+        self._check(data, routine, *args, **kwargs)
+
+    def test_diff(self):
+        for dtype in self.dtypes:
+            self._check_1d(diff, dtype, (16,))
+
+    def test_tilbert(self):
+        for dtype in self.dtypes:
+            self._check_1d(tilbert, dtype, (16,), 1.6)
+
+    def test_itilbert(self):
+        for dtype in self.dtypes:
+            self._check_1d(itilbert, dtype, (16,), 1.6)
+
+    def test_hilbert(self):
+        for dtype in self.dtypes:
+            self._check_1d(hilbert, dtype, (16,))
+
+    def test_cs_diff(self):
+        for dtype in self.dtypes:
+            self._check_1d(cs_diff, dtype, (16,), 1.0, 4.0)
+
+    def test_sc_diff(self):
+        for dtype in self.dtypes:
+            self._check_1d(sc_diff, dtype, (16,), 1.0, 4.0)
+
+    def test_ss_diff(self):
+        for dtype in self.dtypes:
+            self._check_1d(ss_diff, dtype, (16,), 1.0, 4.0)
+
+    def test_cc_diff(self):
+        for dtype in self.dtypes:
+            self._check_1d(cc_diff, dtype, (16,), 1.0, 4.0)
+
+    def test_shift(self):
+        for dtype in self.dtypes:
+            self._check_1d(shift, dtype, (16,), 1.0)

venv/lib/python3.12/site-packages/scipy/fftpack/tests/test_real_transforms.py

@@ -0,0 +1,815 @@
+from os.path import join, dirname
+
+import numpy as np
+from numpy.testing import assert_array_almost_equal, assert_equal
+import pytest
+from pytest import raises as assert_raises
+
+from scipy.fftpack._realtransforms import (
+    dct, idct, dst, idst, dctn, idctn, dstn, idstn)
+
+# Matlab reference data
+MDATA = np.load(join(dirname(__file__), 'test.npz'))
+X = [MDATA['x%d' % i] for i in range(8)]
+Y = [MDATA['y%d' % i] for i in range(8)]
+
+# FFTW reference data: the data are organized as follows:
+#    * SIZES is an array containing all available sizes
+#    * for every type (1, 2, 3, 4) and every size, the array dct_type_size
+#    contains the output of the DCT applied to the input np.linspace(0, size-1,
+#    size)
+FFTWDATA_DOUBLE = np.load(join(dirname(__file__), 'fftw_double_ref.npz'))
+FFTWDATA_SINGLE = np.load(join(dirname(__file__), 'fftw_single_ref.npz'))
+FFTWDATA_SIZES = FFTWDATA_DOUBLE['sizes']
+
+
+def fftw_dct_ref(type, size, dt):
+    x = np.linspace(0, size-1, size).astype(dt)
+    dt = np.result_type(np.float32, dt)
+    if dt == np.float64:
+        data = FFTWDATA_DOUBLE
+    elif dt == np.float32:
+        data = FFTWDATA_SINGLE
+    else:
+        raise ValueError()
+    y = (data['dct_%d_%d' % (type, size)]).astype(dt)
+    return x, y, dt
+
+
+def fftw_dst_ref(type, size, dt):
+    x = np.linspace(0, size-1, size).astype(dt)
+    dt = np.result_type(np.float32, dt)
+    if dt == np.float64:
+        data = FFTWDATA_DOUBLE
+    elif dt == np.float32:
+        data = FFTWDATA_SINGLE
+    else:
+        raise ValueError()
+    y = (data['dst_%d_%d' % (type, size)]).astype(dt)
+    return x, y, dt
+
+
+def dct_2d_ref(x, **kwargs):
+    """Calculate reference values for testing dct2."""
+    x = np.array(x, copy=True)
+    for row in range(x.shape[0]):
+        x[row, :] = dct(x[row, :], **kwargs)
+    for col in range(x.shape[1]):
+        x[:, col] = dct(x[:, col], **kwargs)
+    return x
+
+
+def idct_2d_ref(x, **kwargs):
+    """Calculate reference values for testing idct2."""
+    x = np.array(x, copy=True)
+    for row in range(x.shape[0]):
+        x[row, :] = idct(x[row, :], **kwargs)
+    for col in range(x.shape[1]):
+        x[:, col] = idct(x[:, col], **kwargs)
+    return x
+
+
+def dst_2d_ref(x, **kwargs):
+    """Calculate reference values for testing dst2."""
+    x = np.array(x, copy=True)
+    for row in range(x.shape[0]):
+        x[row, :] = dst(x[row, :], **kwargs)
+    for col in range(x.shape[1]):
+        x[:, col] = dst(x[:, col], **kwargs)
+    return x
+
+
+def idst_2d_ref(x, **kwargs):
+    """Calculate reference values for testing idst2."""
+    x = np.array(x, copy=True)
+    for row in range(x.shape[0]):
+        x[row, :] = idst(x[row, :], **kwargs)
+    for col in range(x.shape[1]):
+        x[:, col] = idst(x[:, col], **kwargs)
+    return x
+
+
+def naive_dct1(x, norm=None):
+    """Calculate textbook definition version of DCT-I."""
+    x = np.array(x, copy=True)
+    N = len(x)
+    M = N-1
+    y = np.zeros(N)
+    m0, m = 1, 2
+    if norm == 'ortho':
+        m0 = np.sqrt(1.0/M)
+        m = np.sqrt(2.0/M)
+    for k in range(N):
+        for n in range(1, N-1):
+            y[k] += m*x[n]*np.cos(np.pi*n*k/M)
+        y[k] += m0 * x[0]
+        y[k] += m0 * x[N-1] * (1 if k % 2 == 0 else -1)
+    if norm == 'ortho':
+        y[0] *= 1/np.sqrt(2)
+        y[N-1] *= 1/np.sqrt(2)
+    return y
+
+
+def naive_dst1(x, norm=None):
+    """Calculate textbook definition version  of DST-I."""
+    x = np.array(x, copy=True)
+    N = len(x)
+    M = N+1
+    y = np.zeros(N)
+    for k in range(N):
+        for n in range(N):
+            y[k] += 2*x[n]*np.sin(np.pi*(n+1.0)*(k+1.0)/M)
+    if norm == 'ortho':
+        y *= np.sqrt(0.5/M)
+    return y
+
+
+def naive_dct4(x, norm=None):
+    """Calculate textbook definition version of DCT-IV."""
+    x = np.array(x, copy=True)
+    N = len(x)
+    y = np.zeros(N)
+    for k in range(N):
+        for n in range(N):
+            y[k] += x[n]*np.cos(np.pi*(n+0.5)*(k+0.5)/(N))
+    if norm == 'ortho':
+        y *= np.sqrt(2.0/N)
+    else:
+        y *= 2
+    return y
+
+
+def naive_dst4(x, norm=None):
+    """Calculate textbook definition version of DST-IV."""
+    x = np.array(x, copy=True)
+    N = len(x)
+    y = np.zeros(N)
+    for k in range(N):
+        for n in range(N):
+            y[k] += x[n]*np.sin(np.pi*(n+0.5)*(k+0.5)/(N))
+    if norm == 'ortho':
+        y *= np.sqrt(2.0/N)
+    else:
+        y *= 2
+    return y
+
+
+class TestComplex:
+    def test_dct_complex64(self):
+        y = dct(1j*np.arange(5, dtype=np.complex64))
+        x = 1j*dct(np.arange(5))
+        assert_array_almost_equal(x, y)
+
+    def test_dct_complex(self):
+        y = dct(np.arange(5)*1j)
+        x = 1j*dct(np.arange(5))
+        assert_array_almost_equal(x, y)
+
+    def test_idct_complex(self):
+        y = idct(np.arange(5)*1j)
+        x = 1j*idct(np.arange(5))
+        assert_array_almost_equal(x, y)
+
+    def test_dst_complex64(self):
+        y = dst(np.arange(5, dtype=np.complex64)*1j)
+        x = 1j*dst(np.arange(5))
+        assert_array_almost_equal(x, y)
+
+    def test_dst_complex(self):
+        y = dst(np.arange(5)*1j)
+        x = 1j*dst(np.arange(5))
+        assert_array_almost_equal(x, y)
+
+    def test_idst_complex(self):
+        y = idst(np.arange(5)*1j)
+        x = 1j*idst(np.arange(5))
+        assert_array_almost_equal(x, y)
+
+
+class _TestDCTBase:
+    def setup_method(self):
+        self.rdt = None
+        self.dec = 14
+        self.type = None
+
+    def test_definition(self):
+        for i in FFTWDATA_SIZES:
+            x, yr, dt = fftw_dct_ref(self.type, i, self.rdt)
+            y = dct(x, type=self.type)
+            assert_equal(y.dtype, dt)
+            # XXX: we divide by np.max(y) because the tests fail otherwise. We
+            # should really use something like assert_array_approx_equal. The
+            # difference is due to fftw using a better algorithm w.r.t error
+            # propagation compared to the ones from fftpack.
+            assert_array_almost_equal(y / np.max(y), yr / np.max(y), decimal=self.dec,
+                    err_msg="Size %d failed" % i)
+
+    def test_axis(self):
+        nt = 2
+        for i in [7, 8, 9, 16, 32, 64]:
+            x = np.random.randn(nt, i)
+            y = dct(x, type=self.type)
+            for j in range(nt):
+                assert_array_almost_equal(y[j], dct(x[j], type=self.type),
+                        decimal=self.dec)
+
+            x = x.T
+            y = dct(x, axis=0, type=self.type)
+            for j in range(nt):
+                assert_array_almost_equal(y[:,j], dct(x[:,j], type=self.type),
+                        decimal=self.dec)
+
+
+class _TestDCTIBase(_TestDCTBase):
+    def test_definition_ortho(self):
+        # Test orthornomal mode.
+        dt = np.result_type(np.float32, self.rdt)
+        for xr in X:
+            x = np.array(xr, dtype=self.rdt)
+            y = dct(x, norm='ortho', type=1)
+            y2 = naive_dct1(x, norm='ortho')
+            assert_equal(y.dtype, dt)
+            assert_array_almost_equal(y / np.max(y), y2 / np.max(y), decimal=self.dec)
+
+class _TestDCTIIBase(_TestDCTBase):
+    def test_definition_matlab(self):
+        # Test correspondence with MATLAB (orthornomal mode).
+        dt = np.result_type(np.float32, self.rdt)
+        for xr, yr in zip(X, Y):
+            x = np.array(xr, dtype=dt)
+            y = dct(x, norm="ortho", type=2)
+            assert_equal(y.dtype, dt)
+            assert_array_almost_equal(y, yr, decimal=self.dec)
+
+
+class _TestDCTIIIBase(_TestDCTBase):
+    def test_definition_ortho(self):
+        # Test orthornomal mode.
+        dt = np.result_type(np.float32, self.rdt)
+        for xr in X:
+            x = np.array(xr, dtype=self.rdt)
+            y = dct(x, norm='ortho', type=2)
+            xi = dct(y, norm="ortho", type=3)
+            assert_equal(xi.dtype, dt)
+            assert_array_almost_equal(xi, x, decimal=self.dec)
+
+class _TestDCTIVBase(_TestDCTBase):
+    def test_definition_ortho(self):
+        # Test orthornomal mode.
+        dt = np.result_type(np.float32, self.rdt)
+        for xr in X:
+            x = np.array(xr, dtype=self.rdt)
+            y = dct(x, norm='ortho', type=4)
+            y2 = naive_dct4(x, norm='ortho')
+            assert_equal(y.dtype, dt)
+            assert_array_almost_equal(y / np.max(y), y2 / np.max(y), decimal=self.dec)
+
+
+class TestDCTIDouble(_TestDCTIBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 10
+        self.type = 1
+
+
+class TestDCTIFloat(_TestDCTIBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 4
+        self.type = 1
+
+
+class TestDCTIInt(_TestDCTIBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 5
+        self.type = 1
+
+
+class TestDCTIIDouble(_TestDCTIIBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 10
+        self.type = 2
+
+
+class TestDCTIIFloat(_TestDCTIIBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 5
+        self.type = 2
+
+
+class TestDCTIIInt(_TestDCTIIBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 5
+        self.type = 2
+
+
+class TestDCTIIIDouble(_TestDCTIIIBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 14
+        self.type = 3
+
+
+class TestDCTIIIFloat(_TestDCTIIIBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 5
+        self.type = 3
+
+
+class TestDCTIIIInt(_TestDCTIIIBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 5
+        self.type = 3
+
+
+class TestDCTIVDouble(_TestDCTIVBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 12
+        self.type = 3
+
+
+class TestDCTIVFloat(_TestDCTIVBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 5
+        self.type = 3
+
+
+class TestDCTIVInt(_TestDCTIVBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 5
+        self.type = 3
+
+
+class _TestIDCTBase:
+    def setup_method(self):
+        self.rdt = None
+        self.dec = 14
+        self.type = None
+
+    def test_definition(self):
+        for i in FFTWDATA_SIZES:
+            xr, yr, dt = fftw_dct_ref(self.type, i, self.rdt)
+            x = idct(yr, type=self.type)
+            if self.type == 1:
+                x /= 2 * (i-1)
+            else:
+                x /= 2 * i
+            assert_equal(x.dtype, dt)
+            # XXX: we divide by np.max(y) because the tests fail otherwise. We
+            # should really use something like assert_array_approx_equal. The
+            # difference is due to fftw using a better algorithm w.r.t error
+            # propagation compared to the ones from fftpack.
+            assert_array_almost_equal(x / np.max(x), xr / np.max(x), decimal=self.dec,
+                    err_msg="Size %d failed" % i)
+
+
+class TestIDCTIDouble(_TestIDCTBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 10
+        self.type = 1
+
+
+class TestIDCTIFloat(_TestIDCTBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 4
+        self.type = 1
+
+
+class TestIDCTIInt(_TestIDCTBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 4
+        self.type = 1
+
+
+class TestIDCTIIDouble(_TestIDCTBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 10
+        self.type = 2
+
+
+class TestIDCTIIFloat(_TestIDCTBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 5
+        self.type = 2
+
+
+class TestIDCTIIInt(_TestIDCTBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 5
+        self.type = 2
+
+
+class TestIDCTIIIDouble(_TestIDCTBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 14
+        self.type = 3
+
+
+class TestIDCTIIIFloat(_TestIDCTBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 5
+        self.type = 3
+
+
+class TestIDCTIIIInt(_TestIDCTBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 5
+        self.type = 3
+
+class TestIDCTIVDouble(_TestIDCTBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 12
+        self.type = 4
+
+
+class TestIDCTIVFloat(_TestIDCTBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 5
+        self.type = 4
+
+
+class TestIDCTIVInt(_TestIDCTBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 5
+        self.type = 4
+
+class _TestDSTBase:
+    def setup_method(self):
+        self.rdt = None  # dtype
+        self.dec = None  # number of decimals to match
+        self.type = None  # dst type
+
+    def test_definition(self):
+        for i in FFTWDATA_SIZES:
+            xr, yr, dt = fftw_dst_ref(self.type, i, self.rdt)
+            y = dst(xr, type=self.type)
+            assert_equal(y.dtype, dt)
+            # XXX: we divide by np.max(y) because the tests fail otherwise. We
+            # should really use something like assert_array_approx_equal. The
+            # difference is due to fftw using a better algorithm w.r.t error
+            # propagation compared to the ones from fftpack.
+            assert_array_almost_equal(y / np.max(y), yr / np.max(y), decimal=self.dec,
+                    err_msg="Size %d failed" % i)
+
+
+class _TestDSTIBase(_TestDSTBase):
+    def test_definition_ortho(self):
+        # Test orthornomal mode.
+        dt = np.result_type(np.float32, self.rdt)
+        for xr in X:
+            x = np.array(xr, dtype=self.rdt)
+            y = dst(x, norm='ortho', type=1)
+            y2 = naive_dst1(x, norm='ortho')
+            assert_equal(y.dtype, dt)
+            assert_array_almost_equal(y / np.max(y), y2 / np.max(y), decimal=self.dec)
+
+class _TestDSTIVBase(_TestDSTBase):
+    def test_definition_ortho(self):
+        # Test orthornomal mode.
+        dt = np.result_type(np.float32, self.rdt)
+        for xr in X:
+            x = np.array(xr, dtype=self.rdt)
+            y = dst(x, norm='ortho', type=4)
+            y2 = naive_dst4(x, norm='ortho')
+            assert_equal(y.dtype, dt)
+            assert_array_almost_equal(y, y2, decimal=self.dec)
+
+class TestDSTIDouble(_TestDSTIBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 12
+        self.type = 1
+
+
+class TestDSTIFloat(_TestDSTIBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 4
+        self.type = 1
+
+
+class TestDSTIInt(_TestDSTIBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 5
+        self.type = 1
+
+
+class TestDSTIIDouble(_TestDSTBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 14
+        self.type = 2
+
+
+class TestDSTIIFloat(_TestDSTBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 6
+        self.type = 2
+
+
+class TestDSTIIInt(_TestDSTBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 6
+        self.type = 2
+
+
+class TestDSTIIIDouble(_TestDSTBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 14
+        self.type = 3
+
+
+class TestDSTIIIFloat(_TestDSTBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 7
+        self.type = 3
+
+
+class TestDSTIIIInt(_TestDSTBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 7
+        self.type = 3
+
+
+class TestDSTIVDouble(_TestDSTIVBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 12
+        self.type = 4
+
+
+class TestDSTIVFloat(_TestDSTIVBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 4
+        self.type = 4
+
+
+class TestDSTIVInt(_TestDSTIVBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 5
+        self.type = 4
+
+
+class _TestIDSTBase:
+    def setup_method(self):
+        self.rdt = None
+        self.dec = None
+        self.type = None
+
+    def test_definition(self):
+        for i in FFTWDATA_SIZES:
+            xr, yr, dt = fftw_dst_ref(self.type, i, self.rdt)
+            x = idst(yr, type=self.type)
+            if self.type == 1:
+                x /= 2 * (i+1)
+            else:
+                x /= 2 * i
+            assert_equal(x.dtype, dt)
+            # XXX: we divide by np.max(x) because the tests fail otherwise. We
+            # should really use something like assert_array_approx_equal. The
+            # difference is due to fftw using a better algorithm w.r.t error
+            # propagation compared to the ones from fftpack.
+            assert_array_almost_equal(x / np.max(x), xr / np.max(x), decimal=self.dec,
+                    err_msg="Size %d failed" % i)
+
+
+class TestIDSTIDouble(_TestIDSTBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 12
+        self.type = 1
+
+
+class TestIDSTIFloat(_TestIDSTBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 4
+        self.type = 1
+
+
+class TestIDSTIInt(_TestIDSTBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 4
+        self.type = 1
+
+
+class TestIDSTIIDouble(_TestIDSTBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 14
+        self.type = 2
+
+
+class TestIDSTIIFloat(_TestIDSTBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 6
+        self.type = 2
+
+
+class TestIDSTIIInt(_TestIDSTBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 6
+        self.type = 2
+
+
+class TestIDSTIIIDouble(_TestIDSTBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 14
+        self.type = 3
+
+
+class TestIDSTIIIFloat(_TestIDSTBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 6
+        self.type = 3
+
+
+class TestIDSTIIIInt(_TestIDSTBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 6
+        self.type = 3
+
+
+class TestIDSTIVDouble(_TestIDSTBase):
+    def setup_method(self):
+        self.rdt = np.float64
+        self.dec = 12
+        self.type = 4
+
+
+class TestIDSTIVFloat(_TestIDSTBase):
+    def setup_method(self):
+        self.rdt = np.float32
+        self.dec = 6
+        self.type = 4
+
+
+class TestIDSTIVnt(_TestIDSTBase):
+    def setup_method(self):
+        self.rdt = int
+        self.dec = 6
+        self.type = 4
+
+
+class TestOverwrite:
+    """Check input overwrite behavior."""
+
+    real_dtypes = [np.float32, np.float64]
+
+    def _check(self, x, routine, type, fftsize, axis, norm, overwrite_x, **kw):
+        x2 = x.copy()
+        routine(x2, type, fftsize, axis, norm, overwrite_x=overwrite_x)
+
+        sig = "{}({}{!r}, {!r}, axis={!r}, overwrite_x={!r})".format(
+            routine.__name__, x.dtype, x.shape, fftsize, axis, overwrite_x)
+        if not overwrite_x:
+            assert_equal(x2, x, err_msg="spurious overwrite in %s" % sig)
+
+    def _check_1d(self, routine, dtype, shape, axis):
+        np.random.seed(1234)
+        if np.issubdtype(dtype, np.complexfloating):
+            data = np.random.randn(*shape) + 1j*np.random.randn(*shape)
+        else:
+            data = np.random.randn(*shape)
+        data = data.astype(dtype)
+
+        for type in [1, 2, 3, 4]:
+            for overwrite_x in [True, False]:
+                for norm in [None, 'ortho']:
+                    self._check(data, routine, type, None, axis, norm,
+                                overwrite_x)
+
+    def test_dct(self):
+        for dtype in self.real_dtypes:
+            self._check_1d(dct, dtype, (16,), -1)
+            self._check_1d(dct, dtype, (16, 2), 0)
+            self._check_1d(dct, dtype, (2, 16), 1)
+
+    def test_idct(self):
+        for dtype in self.real_dtypes:
+            self._check_1d(idct, dtype, (16,), -1)
+            self._check_1d(idct, dtype, (16, 2), 0)
+            self._check_1d(idct, dtype, (2, 16), 1)
+
+    def test_dst(self):
+        for dtype in self.real_dtypes:
+            self._check_1d(dst, dtype, (16,), -1)
+            self._check_1d(dst, dtype, (16, 2), 0)
+            self._check_1d(dst, dtype, (2, 16), 1)
+
+    def test_idst(self):
+        for dtype in self.real_dtypes:
+            self._check_1d(idst, dtype, (16,), -1)
+            self._check_1d(idst, dtype, (16, 2), 0)
+            self._check_1d(idst, dtype, (2, 16), 1)
+
+
+class Test_DCTN_IDCTN:
+    dec = 14
+    dct_type = [1, 2, 3, 4]
+    norms = [None, 'ortho']
+    rstate = np.random.RandomState(1234)
+    shape = (32, 16)
+    data = rstate.randn(*shape)
+
+    @pytest.mark.parametrize('fforward,finverse', [(dctn, idctn),
+                                                   (dstn, idstn)])
+    @pytest.mark.parametrize('axes', [None,
+                                      1, (1,), [1],
+                                      0, (0,), [0],
+                                      (0, 1), [0, 1],
+                                      (-2, -1), [-2, -1]])
+    @pytest.mark.parametrize('dct_type', dct_type)
+    @pytest.mark.parametrize('norm', ['ortho'])
+    def test_axes_round_trip(self, fforward, finverse, axes, dct_type, norm):
+        tmp = fforward(self.data, type=dct_type, axes=axes, norm=norm)
+        tmp = finverse(tmp, type=dct_type, axes=axes, norm=norm)
+        assert_array_almost_equal(self.data, tmp, decimal=12)
+
+    @pytest.mark.parametrize('fforward,fforward_ref', [(dctn, dct_2d_ref),
+                                                       (dstn, dst_2d_ref)])
+    @pytest.mark.parametrize('dct_type', dct_type)
+    @pytest.mark.parametrize('norm', norms)
+    def test_dctn_vs_2d_reference(self, fforward, fforward_ref,
+                                  dct_type, norm):
+        y1 = fforward(self.data, type=dct_type, axes=None, norm=norm)
+        y2 = fforward_ref(self.data, type=dct_type, norm=norm)
+        assert_array_almost_equal(y1, y2, decimal=11)
+
+    @pytest.mark.parametrize('finverse,finverse_ref', [(idctn, idct_2d_ref),
+                                                       (idstn, idst_2d_ref)])
+    @pytest.mark.parametrize('dct_type', dct_type)
+    @pytest.mark.parametrize('norm', [None, 'ortho'])
+    def test_idctn_vs_2d_reference(self, finverse, finverse_ref,
+                                   dct_type, norm):
+        fdata = dctn(self.data, type=dct_type, norm=norm)
+        y1 = finverse(fdata, type=dct_type, norm=norm)
+        y2 = finverse_ref(fdata, type=dct_type, norm=norm)
+        assert_array_almost_equal(y1, y2, decimal=11)
+
+    @pytest.mark.parametrize('fforward,finverse', [(dctn, idctn),
+                                                   (dstn, idstn)])
+    def test_axes_and_shape(self, fforward, finverse):
+        with assert_raises(ValueError,
+                           match="when given, axes and shape arguments"
+                           " have to be of the same length"):
+            fforward(self.data, shape=self.data.shape[0], axes=(0, 1))
+
+        with assert_raises(ValueError,
+                           match="when given, axes and shape arguments"
+                           " have to be of the same length"):
+            fforward(self.data, shape=self.data.shape[0], axes=None)
+
+        with assert_raises(ValueError,
+                           match="when given, axes and shape arguments"
+                           " have to be of the same length"):
+            fforward(self.data, shape=self.data.shape, axes=0)
+
+    @pytest.mark.parametrize('fforward', [dctn, dstn])
+    def test_shape(self, fforward):
+        tmp = fforward(self.data, shape=(128, 128), axes=None)
+        assert_equal(tmp.shape, (128, 128))
+
+    @pytest.mark.parametrize('fforward,finverse', [(dctn, idctn),
+                                                   (dstn, idstn)])
+    @pytest.mark.parametrize('axes', [1, (1,), [1],
+                                      0, (0,), [0]])
+    def test_shape_is_none_with_axes(self, fforward, finverse, axes):
+        tmp = fforward(self.data, shape=None, axes=axes, norm='ortho')
+        tmp = finverse(tmp, shape=None, axes=axes, norm='ortho')
+        assert_array_almost_equal(self.data, tmp, decimal=self.dec)