Updated script that can be controled by Nodejs web app

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"""
Discrete Fourier Transform (:mod:`numpy.fft`)
=============================================
.. currentmodule:: numpy.fft
The SciPy module `scipy.fft` is a more comprehensive superset
of ``numpy.fft``, which includes only a basic set of routines.
Standard FFTs
-------------
.. autosummary::
:toctree: generated/
fft Discrete Fourier transform.
ifft Inverse discrete Fourier transform.
fft2 Discrete Fourier transform in two dimensions.
ifft2 Inverse discrete Fourier transform in two dimensions.
fftn Discrete Fourier transform in N-dimensions.
ifftn Inverse discrete Fourier transform in N dimensions.
Real FFTs
---------
.. autosummary::
:toctree: generated/
rfft Real discrete Fourier transform.
irfft Inverse real discrete Fourier transform.
rfft2 Real discrete Fourier transform in two dimensions.
irfft2 Inverse real discrete Fourier transform in two dimensions.
rfftn Real discrete Fourier transform in N dimensions.
irfftn Inverse real discrete Fourier transform in N dimensions.
Hermitian FFTs
--------------
.. autosummary::
:toctree: generated/
hfft Hermitian discrete Fourier transform.
ihfft Inverse Hermitian discrete Fourier transform.
Helper routines
---------------
.. autosummary::
:toctree: generated/
fftfreq Discrete Fourier Transform sample frequencies.
rfftfreq DFT sample frequencies (for usage with rfft, irfft).
fftshift Shift zero-frequency component to center of spectrum.
ifftshift Inverse of fftshift.
Background information
----------------------
Fourier analysis is fundamentally a method for expressing a function as a
sum of periodic components, and for recovering the function from those
components. When both the function and its Fourier transform are
replaced with discretized counterparts, it is called the discrete Fourier
transform (DFT). The DFT has become a mainstay of numerical computing in
part because of a very fast algorithm for computing it, called the Fast
Fourier Transform (FFT), which was known to Gauss (1805) and was brought
to light in its current form by Cooley and Tukey [CT]_. Press et al. [NR]_
provide an accessible introduction to Fourier analysis and its
applications.
Because the discrete Fourier transform separates its input into
components that contribute at discrete frequencies, it has a great number
of applications in digital signal processing, e.g., for filtering, and in
this context the discretized input to the transform is customarily
referred to as a *signal*, which exists in the *time domain*. The output
is called a *spectrum* or *transform* and exists in the *frequency
domain*.
Implementation details
----------------------
There are many ways to define the DFT, varying in the sign of the
exponent, normalization, etc. In this implementation, the DFT is defined
as
.. math::
A_k = \\sum_{m=0}^{n-1} a_m \\exp\\left\\{-2\\pi i{mk \\over n}\\right\\}
\\qquad k = 0,\\ldots,n-1.
The DFT is in general defined for complex inputs and outputs, and a
single-frequency component at linear frequency :math:`f` is
represented by a complex exponential
:math:`a_m = \\exp\\{2\\pi i\\,f m\\Delta t\\}`, where :math:`\\Delta t`
is the sampling interval.
The values in the result follow so-called "standard" order: If ``A =
fft(a, n)``, then ``A[0]`` contains the zero-frequency term (the sum of
the signal), which is always purely real for real inputs. Then ``A[1:n/2]``
contains the positive-frequency terms, and ``A[n/2+1:]`` contains the
negative-frequency terms, in order of decreasingly negative frequency.
For an even number of input points, ``A[n/2]`` represents both positive and
negative Nyquist frequency, and is also purely real for real input. For
an odd number of input points, ``A[(n-1)/2]`` contains the largest positive
frequency, while ``A[(n+1)/2]`` contains the largest negative frequency.
The routine ``np.fft.fftfreq(n)`` returns an array giving the frequencies
of corresponding elements in the output. The routine
``np.fft.fftshift(A)`` shifts transforms and their frequencies to put the
zero-frequency components in the middle, and ``np.fft.ifftshift(A)`` undoes
that shift.
When the input `a` is a time-domain signal and ``A = fft(a)``, ``np.abs(A)``
is its amplitude spectrum and ``np.abs(A)**2`` is its power spectrum.
The phase spectrum is obtained by ``np.angle(A)``.
The inverse DFT is defined as
.. math::
a_m = \\frac{1}{n}\\sum_{k=0}^{n-1}A_k\\exp\\left\\{2\\pi i{mk\\over n}\\right\\}
\\qquad m = 0,\\ldots,n-1.
It differs from the forward transform by the sign of the exponential
argument and the default normalization by :math:`1/n`.
Type Promotion
--------------
`numpy.fft` promotes ``float32`` and ``complex64`` arrays to ``float64`` and
``complex128`` arrays respectively. For an FFT implementation that does not
promote input arrays, see `scipy.fftpack`.
Normalization
-------------
The argument ``norm`` indicates which direction of the pair of direct/inverse
transforms is scaled and with what normalization factor.
The default normalization (``"backward"``) has the direct (forward) transforms
unscaled and the inverse (backward) transforms scaled by :math:`1/n`. It is
possible to obtain unitary transforms by setting the keyword argument ``norm``
to ``"ortho"`` so that both direct and inverse transforms are scaled by
:math:`1/\\sqrt{n}`. Finally, setting the keyword argument ``norm`` to
``"forward"`` has the direct transforms scaled by :math:`1/n` and the inverse
transforms unscaled (i.e. exactly opposite to the default ``"backward"``).
`None` is an alias of the default option ``"backward"`` for backward
compatibility.
Real and Hermitian transforms
-----------------------------
When the input is purely real, its transform is Hermitian, i.e., the
component at frequency :math:`f_k` is the complex conjugate of the
component at frequency :math:`-f_k`, which means that for real
inputs there is no information in the negative frequency components that
is not already available from the positive frequency components.
The family of `rfft` functions is
designed to operate on real inputs, and exploits this symmetry by
computing only the positive frequency components, up to and including the
Nyquist frequency. Thus, ``n`` input points produce ``n/2+1`` complex
output points. The inverses of this family assumes the same symmetry of
its input, and for an output of ``n`` points uses ``n/2+1`` input points.
Correspondingly, when the spectrum is purely real, the signal is
Hermitian. The `hfft` family of functions exploits this symmetry by
using ``n/2+1`` complex points in the input (time) domain for ``n`` real
points in the frequency domain.
In higher dimensions, FFTs are used, e.g., for image analysis and
filtering. The computational efficiency of the FFT means that it can
also be a faster way to compute large convolutions, using the property
that a convolution in the time domain is equivalent to a point-by-point
multiplication in the frequency domain.
Higher dimensions
-----------------
In two dimensions, the DFT is defined as
.. math::
A_{kl} = \\sum_{m=0}^{M-1} \\sum_{n=0}^{N-1}
a_{mn}\\exp\\left\\{-2\\pi i \\left({mk\\over M}+{nl\\over N}\\right)\\right\\}
\\qquad k = 0, \\ldots, M-1;\\quad l = 0, \\ldots, N-1,
which extends in the obvious way to higher dimensions, and the inverses
in higher dimensions also extend in the same way.
References
----------
.. [CT] Cooley, James W., and John W. Tukey, 1965, "An algorithm for the
machine calculation of complex Fourier series," *Math. Comput.*
19: 297-301.
.. [NR] Press, W., Teukolsky, S., Vetterline, W.T., and Flannery, B.P.,
2007, *Numerical Recipes: The Art of Scientific Computing*, ch.
12-13. Cambridge Univ. Press, Cambridge, UK.
Examples
--------
For examples, see the various functions.
"""
from . import _pocketfft, _helper
# TODO: `numpy.fft.helper`` was deprecated in NumPy 2.0. It should
# be deleted once downstream libraries move to `numpy.fft`.
from . import helper
from ._pocketfft import *
from ._helper import *
__all__ = _pocketfft.__all__.copy()
__all__ += _helper.__all__
from numpy._pytesttester import PytestTester
test = PytestTester(__name__)
del PytestTester

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from numpy._pytesttester import PytestTester
from numpy.fft._pocketfft import (
fft as fft,
ifft as ifft,
rfft as rfft,
irfft as irfft,
hfft as hfft,
ihfft as ihfft,
rfftn as rfftn,
irfftn as irfftn,
rfft2 as rfft2,
irfft2 as irfft2,
fft2 as fft2,
ifft2 as ifft2,
fftn as fftn,
ifftn as ifftn,
)
from numpy.fft._helper import (
fftshift as fftshift,
ifftshift as ifftshift,
fftfreq as fftfreq,
rfftfreq as rfftfreq,
)
__all__: list[str]
test: PytestTester

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"""
Discrete Fourier Transforms - _helper.py
"""
from numpy._core import integer, empty, arange, asarray, roll
from numpy._core.overrides import array_function_dispatch, set_module
# Created by Pearu Peterson, September 2002
__all__ = ['fftshift', 'ifftshift', 'fftfreq', 'rfftfreq']
integer_types = (int, integer)
def _fftshift_dispatcher(x, axes=None):
return (x,)
@array_function_dispatch(_fftshift_dispatcher, module='numpy.fft')
def fftshift(x, axes=None):
"""
Shift the zero-frequency component to the center of the spectrum.
This function swaps half-spaces for all axes listed (defaults to all).
Note that ``y[0]`` is the Nyquist component only if ``len(x)`` is even.
Parameters
----------
x : array_like
Input array.
axes : int or shape tuple, optional
Axes over which to shift. Default is None, which shifts all axes.
Returns
-------
y : ndarray
The shifted array.
See Also
--------
ifftshift : The inverse of `fftshift`.
Examples
--------
>>> import numpy as np
>>> freqs = np.fft.fftfreq(10, 0.1)
>>> freqs
array([ 0., 1., 2., ..., -3., -2., -1.])
>>> np.fft.fftshift(freqs)
array([-5., -4., -3., -2., -1., 0., 1., 2., 3., 4.])
Shift the zero-frequency component only along the second axis:
>>> freqs = np.fft.fftfreq(9, d=1./9).reshape(3, 3)
>>> freqs
array([[ 0., 1., 2.],
[ 3., 4., -4.],
[-3., -2., -1.]])
>>> np.fft.fftshift(freqs, axes=(1,))
array([[ 2., 0., 1.],
[-4., 3., 4.],
[-1., -3., -2.]])
"""
x = asarray(x)
if axes is None:
axes = tuple(range(x.ndim))
shift = [dim // 2 for dim in x.shape]
elif isinstance(axes, integer_types):
shift = x.shape[axes] // 2
else:
shift = [x.shape[ax] // 2 for ax in axes]
return roll(x, shift, axes)
@array_function_dispatch(_fftshift_dispatcher, module='numpy.fft')
def ifftshift(x, axes=None):
"""
The inverse of `fftshift`. Although identical for even-length `x`, the
functions differ by one sample for odd-length `x`.
Parameters
----------
x : array_like
Input array.
axes : int or shape tuple, optional
Axes over which to calculate. Defaults to None, which shifts all axes.
Returns
-------
y : ndarray
The shifted array.
See Also
--------
fftshift : Shift zero-frequency component to the center of the spectrum.
Examples
--------
>>> import numpy as np
>>> freqs = np.fft.fftfreq(9, d=1./9).reshape(3, 3)
>>> freqs
array([[ 0., 1., 2.],
[ 3., 4., -4.],
[-3., -2., -1.]])
>>> np.fft.ifftshift(np.fft.fftshift(freqs))
array([[ 0., 1., 2.],
[ 3., 4., -4.],
[-3., -2., -1.]])
"""
x = asarray(x)
if axes is None:
axes = tuple(range(x.ndim))
shift = [-(dim // 2) for dim in x.shape]
elif isinstance(axes, integer_types):
shift = -(x.shape[axes] // 2)
else:
shift = [-(x.shape[ax] // 2) for ax in axes]
return roll(x, shift, axes)
@set_module('numpy.fft')
def fftfreq(n, d=1.0, device=None):
"""
Return the Discrete Fourier Transform sample frequencies.
The returned float array `f` contains the frequency bin centers in cycles
per unit of the sample spacing (with zero at the start). For instance, if
the sample spacing is in seconds, then the frequency unit is cycles/second.
Given a window length `n` and a sample spacing `d`::
f = [0, 1, ..., n/2-1, -n/2, ..., -1] / (d*n) if n is even
f = [0, 1, ..., (n-1)/2, -(n-1)/2, ..., -1] / (d*n) if n is odd
Parameters
----------
n : int
Window length.
d : scalar, optional
Sample spacing (inverse of the sampling rate). Defaults to 1.
device : str, optional
The device on which to place the created array. Default: ``None``.
For Array-API interoperability only, so must be ``"cpu"`` if passed.
.. versionadded:: 2.0.0
Returns
-------
f : ndarray
Array of length `n` containing the sample frequencies.
Examples
--------
>>> import numpy as np
>>> signal = np.array([-2, 8, 6, 4, 1, 0, 3, 5], dtype=float)
>>> fourier = np.fft.fft(signal)
>>> n = signal.size
>>> timestep = 0.1
>>> freq = np.fft.fftfreq(n, d=timestep)
>>> freq
array([ 0. , 1.25, 2.5 , ..., -3.75, -2.5 , -1.25])
"""
if not isinstance(n, integer_types):
raise ValueError("n should be an integer")
val = 1.0 / (n * d)
results = empty(n, int, device=device)
N = (n-1)//2 + 1
p1 = arange(0, N, dtype=int, device=device)
results[:N] = p1
p2 = arange(-(n//2), 0, dtype=int, device=device)
results[N:] = p2
return results * val
@set_module('numpy.fft')
def rfftfreq(n, d=1.0, device=None):
"""
Return the Discrete Fourier Transform sample frequencies
(for usage with rfft, irfft).
The returned float array `f` contains the frequency bin centers in cycles
per unit of the sample spacing (with zero at the start). For instance, if
the sample spacing is in seconds, then the frequency unit is cycles/second.
Given a window length `n` and a sample spacing `d`::
f = [0, 1, ..., n/2-1, n/2] / (d*n) if n is even
f = [0, 1, ..., (n-1)/2-1, (n-1)/2] / (d*n) if n is odd
Unlike `fftfreq` (but like `scipy.fftpack.rfftfreq`)
the Nyquist frequency component is considered to be positive.
Parameters
----------
n : int
Window length.
d : scalar, optional
Sample spacing (inverse of the sampling rate). Defaults to 1.
device : str, optional
The device on which to place the created array. Default: ``None``.
For Array-API interoperability only, so must be ``"cpu"`` if passed.
.. versionadded:: 2.0.0
Returns
-------
f : ndarray
Array of length ``n//2 + 1`` containing the sample frequencies.
Examples
--------
>>> import numpy as np
>>> signal = np.array([-2, 8, 6, 4, 1, 0, 3, 5, -3, 4], dtype=float)
>>> fourier = np.fft.rfft(signal)
>>> n = signal.size
>>> sample_rate = 100
>>> freq = np.fft.fftfreq(n, d=1./sample_rate)
>>> freq
array([ 0., 10., 20., ..., -30., -20., -10.])
>>> freq = np.fft.rfftfreq(n, d=1./sample_rate)
>>> freq
array([ 0., 10., 20., 30., 40., 50.])
"""
if not isinstance(n, integer_types):
raise ValueError("n should be an integer")
val = 1.0/(n*d)
N = n//2 + 1
results = arange(0, N, dtype=int, device=device)
return results * val

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from typing import Any, TypeVar, overload, Literal as L
from numpy import generic, integer, floating, complexfloating
from numpy._typing import (
NDArray,
ArrayLike,
_ShapeLike,
_ArrayLike,
_ArrayLikeFloat_co,
_ArrayLikeComplex_co,
)
_SCT = TypeVar("_SCT", bound=generic)
__all__: list[str]
@overload
def fftshift(x: _ArrayLike[_SCT], axes: None | _ShapeLike = ...) -> NDArray[_SCT]: ...
@overload
def fftshift(x: ArrayLike, axes: None | _ShapeLike = ...) -> NDArray[Any]: ...
@overload
def ifftshift(x: _ArrayLike[_SCT], axes: None | _ShapeLike = ...) -> NDArray[_SCT]: ...
@overload
def ifftshift(x: ArrayLike, axes: None | _ShapeLike = ...) -> NDArray[Any]: ...
@overload
def fftfreq(
n: int | integer[Any],
d: _ArrayLikeFloat_co = ...,
device: None | L["cpu"] = ...,
) -> NDArray[floating[Any]]: ...
@overload
def fftfreq(
n: int | integer[Any],
d: _ArrayLikeComplex_co = ...,
device: None | L["cpu"] = ...,
) -> NDArray[complexfloating[Any, Any]]: ...
@overload
def rfftfreq(
n: int | integer[Any],
d: _ArrayLikeFloat_co = ...,
device: None | L["cpu"] = ...,
) -> NDArray[floating[Any]]: ...
@overload
def rfftfreq(
n: int | integer[Any],
d: _ArrayLikeComplex_co = ...,
device: None | L["cpu"] = ...,
) -> NDArray[complexfloating[Any, Any]]: ...

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from collections.abc import Sequence
from typing import Literal as L
from numpy import complex128, float64
from numpy._typing import ArrayLike, NDArray, _ArrayLikeNumber_co
_NormKind = L[None, "backward", "ortho", "forward"]
__all__: list[str]
def fft(
a: ArrayLike,
n: None | int = ...,
axis: int = ...,
norm: _NormKind = ...,
out: None | NDArray[complex128] = ...,
) -> NDArray[complex128]: ...
def ifft(
a: ArrayLike,
n: None | int = ...,
axis: int = ...,
norm: _NormKind = ...,
out: None | NDArray[complex128] = ...,
) -> NDArray[complex128]: ...
def rfft(
a: ArrayLike,
n: None | int = ...,
axis: int = ...,
norm: _NormKind = ...,
out: None | NDArray[complex128] = ...,
) -> NDArray[complex128]: ...
def irfft(
a: ArrayLike,
n: None | int = ...,
axis: int = ...,
norm: _NormKind = ...,
out: None | NDArray[float64] = ...,
) -> NDArray[float64]: ...
# Input array must be compatible with `np.conjugate`
def hfft(
a: _ArrayLikeNumber_co,
n: None | int = ...,
axis: int = ...,
norm: _NormKind = ...,
out: None | NDArray[float64] = ...,
) -> NDArray[float64]: ...
def ihfft(
a: ArrayLike,
n: None | int = ...,
axis: int = ...,
norm: _NormKind = ...,
out: None | NDArray[complex128] = ...,
) -> NDArray[complex128]: ...
def fftn(
a: ArrayLike,
s: None | Sequence[int] = ...,
axes: None | Sequence[int] = ...,
norm: _NormKind = ...,
out: None | NDArray[complex128] = ...,
) -> NDArray[complex128]: ...
def ifftn(
a: ArrayLike,
s: None | Sequence[int] = ...,
axes: None | Sequence[int] = ...,
norm: _NormKind = ...,
out: None | NDArray[complex128] = ...,
) -> NDArray[complex128]: ...
def rfftn(
a: ArrayLike,
s: None | Sequence[int] = ...,
axes: None | Sequence[int] = ...,
norm: _NormKind = ...,
out: None | NDArray[complex128] = ...,
) -> NDArray[complex128]: ...
def irfftn(
a: ArrayLike,
s: None | Sequence[int] = ...,
axes: None | Sequence[int] = ...,
norm: _NormKind = ...,
out: None | NDArray[float64] = ...,
) -> NDArray[float64]: ...
def fft2(
a: ArrayLike,
s: None | Sequence[int] = ...,
axes: None | Sequence[int] = ...,
norm: _NormKind = ...,
out: None | NDArray[complex128] = ...,
) -> NDArray[complex128]: ...
def ifft2(
a: ArrayLike,
s: None | Sequence[int] = ...,
axes: None | Sequence[int] = ...,
norm: _NormKind = ...,
out: None | NDArray[complex128] = ...,
) -> NDArray[complex128]: ...
def rfft2(
a: ArrayLike,
s: None | Sequence[int] = ...,
axes: None | Sequence[int] = ...,
norm: _NormKind = ...,
out: None | NDArray[complex128] = ...,
) -> NDArray[complex128]: ...
def irfft2(
a: ArrayLike,
s: None | Sequence[int] = ...,
axes: None | Sequence[int] = ...,
norm: _NormKind = ...,
out: None | NDArray[float64] = ...,
) -> NDArray[float64]: ...

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def __getattr__(attr_name):
import warnings
from numpy.fft import _helper
ret = getattr(_helper, attr_name, None)
if ret is None:
raise AttributeError(
f"module 'numpy.fft.helper' has no attribute {attr_name}")
warnings.warn(
"The numpy.fft.helper has been made private and renamed to "
"numpy.fft._helper. All four functions exported by it (i.e. fftshift, "
"ifftshift, fftfreq, rfftfreq) are available from numpy.fft. "
f"Please use numpy.fft.{attr_name} instead.",
DeprecationWarning,
stacklevel=3
)
return ret

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"""Test functions for fftpack.helper module
Copied from fftpack.helper by Pearu Peterson, October 2005
"""
import numpy as np
from numpy.testing import assert_array_almost_equal
from numpy import fft, pi
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(fft.fftshift(x), y)
assert_array_almost_equal(fft.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(fft.fftshift(x), y)
assert_array_almost_equal(fft.ifftshift(y), x)
def test_inverse(self):
for n in [1, 4, 9, 100, 211]:
x = np.random.random((n,))
assert_array_almost_equal(fft.ifftshift(fft.fftshift(x)), x)
def test_axes_keyword(self):
freqs = [[0, 1, 2], [3, 4, -4], [-3, -2, -1]]
shifted = [[-1, -3, -2], [2, 0, 1], [-4, 3, 4]]
assert_array_almost_equal(fft.fftshift(freqs, axes=(0, 1)), shifted)
assert_array_almost_equal(fft.fftshift(freqs, axes=0),
fft.fftshift(freqs, axes=(0,)))
assert_array_almost_equal(fft.ifftshift(shifted, axes=(0, 1)), freqs)
assert_array_almost_equal(fft.ifftshift(shifted, axes=0),
fft.ifftshift(shifted, axes=(0,)))
assert_array_almost_equal(fft.fftshift(freqs), shifted)
assert_array_almost_equal(fft.ifftshift(shifted), freqs)
def test_uneven_dims(self):
""" Test 2D input, which has uneven dimension sizes """
freqs = [
[0, 1],
[2, 3],
[4, 5]
]
# shift in dimension 0
shift_dim0 = [
[4, 5],
[0, 1],
[2, 3]
]
assert_array_almost_equal(fft.fftshift(freqs, axes=0), shift_dim0)
assert_array_almost_equal(fft.ifftshift(shift_dim0, axes=0), freqs)
assert_array_almost_equal(fft.fftshift(freqs, axes=(0,)), shift_dim0)
assert_array_almost_equal(fft.ifftshift(shift_dim0, axes=[0]), freqs)
# shift in dimension 1
shift_dim1 = [
[1, 0],
[3, 2],
[5, 4]
]
assert_array_almost_equal(fft.fftshift(freqs, axes=1), shift_dim1)
assert_array_almost_equal(fft.ifftshift(shift_dim1, axes=1), freqs)
# shift in both dimensions
shift_dim_both = [
[5, 4],
[1, 0],
[3, 2]
]
assert_array_almost_equal(fft.fftshift(freqs, axes=(0, 1)), shift_dim_both)
assert_array_almost_equal(fft.ifftshift(shift_dim_both, axes=(0, 1)), freqs)
assert_array_almost_equal(fft.fftshift(freqs, axes=[0, 1]), shift_dim_both)
assert_array_almost_equal(fft.ifftshift(shift_dim_both, axes=[0, 1]), freqs)
# axes=None (default) shift in all dimensions
assert_array_almost_equal(fft.fftshift(freqs, axes=None), shift_dim_both)
assert_array_almost_equal(fft.ifftshift(shift_dim_both, axes=None), freqs)
assert_array_almost_equal(fft.fftshift(freqs), shift_dim_both)
assert_array_almost_equal(fft.ifftshift(shift_dim_both), freqs)
def test_equal_to_original(self):
""" Test that the new (>=v1.15) implementation (see #10073) is equal to the original (<=v1.14) """
from numpy._core import asarray, concatenate, arange, take
def original_fftshift(x, axes=None):
""" How fftshift was implemented in v1.14"""
tmp = asarray(x)
ndim = tmp.ndim
if axes is None:
axes = list(range(ndim))
elif isinstance(axes, int):
axes = (axes,)
y = tmp
for k in axes:
n = tmp.shape[k]
p2 = (n + 1) // 2
mylist = concatenate((arange(p2, n), arange(p2)))
y = take(y, mylist, k)
return y
def original_ifftshift(x, axes=None):
""" How ifftshift was implemented in v1.14 """
tmp = asarray(x)
ndim = tmp.ndim
if axes is None:
axes = list(range(ndim))
elif isinstance(axes, int):
axes = (axes,)
y = tmp
for k in axes:
n = tmp.shape[k]
p2 = n - (n + 1) // 2
mylist = concatenate((arange(p2, n), arange(p2)))
y = take(y, mylist, k)
return y
# create possible 2d array combinations and try all possible keywords
# compare output to original functions
for i in range(16):
for j in range(16):
for axes_keyword in [0, 1, None, (0,), (0, 1)]:
inp = np.random.rand(i, j)
assert_array_almost_equal(fft.fftshift(inp, axes_keyword),
original_fftshift(inp, axes_keyword))
assert_array_almost_equal(fft.ifftshift(inp, axes_keyword),
original_ifftshift(inp, axes_keyword))
class TestFFTFreq:
def test_definition(self):
x = [0, 1, 2, 3, 4, -4, -3, -2, -1]
assert_array_almost_equal(9*fft.fftfreq(9), x)
assert_array_almost_equal(9*pi*fft.fftfreq(9, pi), x)
x = [0, 1, 2, 3, 4, -5, -4, -3, -2, -1]
assert_array_almost_equal(10*fft.fftfreq(10), x)
assert_array_almost_equal(10*pi*fft.fftfreq(10, pi), x)
class TestRFFTFreq:
def test_definition(self):
x = [0, 1, 2, 3, 4]
assert_array_almost_equal(9*fft.rfftfreq(9), x)
assert_array_almost_equal(9*pi*fft.rfftfreq(9, pi), x)
x = [0, 1, 2, 3, 4, 5]
assert_array_almost_equal(10*fft.rfftfreq(10), x)
assert_array_almost_equal(10*pi*fft.rfftfreq(10, pi), x)
class TestIRFFTN:
def test_not_last_axis_success(self):
ar, ai = np.random.random((2, 16, 8, 32))
a = ar + 1j*ai
axes = (-2,)
# Should not raise error
fft.irfftn(a, axes=axes)

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@ -0,0 +1,589 @@
import numpy as np
import pytest
from numpy.random import random
from numpy.testing import (
assert_array_equal, assert_raises, assert_allclose, IS_WASM
)
import threading
import queue
def fft1(x):
L = len(x)
phase = -2j * np.pi * (np.arange(L) / L)
phase = np.arange(L).reshape(-1, 1) * phase
return np.sum(x*np.exp(phase), axis=1)
class TestFFTShift:
def test_fft_n(self):
assert_raises(ValueError, np.fft.fft, [1, 2, 3], 0)
class TestFFT1D:
def test_identity(self):
maxlen = 512
x = random(maxlen) + 1j*random(maxlen)
xr = random(maxlen)
for i in range(1, maxlen):
assert_allclose(np.fft.ifft(np.fft.fft(x[0:i])), x[0:i],
atol=1e-12)
assert_allclose(np.fft.irfft(np.fft.rfft(xr[0:i]), i),
xr[0:i], atol=1e-12)
@pytest.mark.parametrize("dtype", [np.single, np.double, np.longdouble])
def test_identity_long_short(self, dtype):
# Test with explicitly given number of points, both for n
# smaller and for n larger than the input size.
maxlen = 16
atol = 5 * np.spacing(np.array(1., dtype=dtype))
x = random(maxlen).astype(dtype) + 1j*random(maxlen).astype(dtype)
xx = np.concatenate([x, np.zeros_like(x)])
xr = random(maxlen).astype(dtype)
xxr = np.concatenate([xr, np.zeros_like(xr)])
for i in range(1, maxlen*2):
check_c = np.fft.ifft(np.fft.fft(x, n=i), n=i)
assert check_c.real.dtype == dtype
assert_allclose(check_c, xx[0:i], atol=atol, rtol=0)
check_r = np.fft.irfft(np.fft.rfft(xr, n=i), n=i)
assert check_r.dtype == dtype
assert_allclose(check_r, xxr[0:i], atol=atol, rtol=0)
@pytest.mark.parametrize("dtype", [np.single, np.double, np.longdouble])
def test_identity_long_short_reversed(self, dtype):
# Also test explicitly given number of points in reversed order.
maxlen = 16
atol = 5 * np.spacing(np.array(1., dtype=dtype))
x = random(maxlen).astype(dtype) + 1j*random(maxlen).astype(dtype)
xx = np.concatenate([x, np.zeros_like(x)])
for i in range(1, maxlen*2):
check_via_c = np.fft.fft(np.fft.ifft(x, n=i), n=i)
assert check_via_c.dtype == x.dtype
assert_allclose(check_via_c, xx[0:i], atol=atol, rtol=0)
# For irfft, we can neither recover the imaginary part of
# the first element, nor the imaginary part of the last
# element if npts is even. So, set to 0 for the comparison.
y = x.copy()
n = i // 2 + 1
y.imag[0] = 0
if i % 2 == 0:
y.imag[n-1:] = 0
yy = np.concatenate([y, np.zeros_like(y)])
check_via_r = np.fft.rfft(np.fft.irfft(x, n=i), n=i)
assert check_via_r.dtype == x.dtype
assert_allclose(check_via_r, yy[0:n], atol=atol, rtol=0)
def test_fft(self):
x = random(30) + 1j*random(30)
assert_allclose(fft1(x), np.fft.fft(x), atol=1e-6)
assert_allclose(fft1(x), np.fft.fft(x, norm="backward"), atol=1e-6)
assert_allclose(fft1(x) / np.sqrt(30),
np.fft.fft(x, norm="ortho"), atol=1e-6)
assert_allclose(fft1(x) / 30.,
np.fft.fft(x, norm="forward"), atol=1e-6)
@pytest.mark.parametrize("axis", (0, 1))
@pytest.mark.parametrize("dtype", (complex, float))
@pytest.mark.parametrize("transpose", (True, False))
def test_fft_out_argument(self, dtype, transpose, axis):
def zeros_like(x):
if transpose:
return np.zeros_like(x.T).T
else:
return np.zeros_like(x)
# tests below only test the out parameter
if dtype is complex:
y = random((10, 20)) + 1j*random((10, 20))
fft, ifft = np.fft.fft, np.fft.ifft
else:
y = random((10, 20))
fft, ifft = np.fft.rfft, np.fft.irfft
expected = fft(y, axis=axis)
out = zeros_like(expected)
result = fft(y, out=out, axis=axis)
assert result is out
assert_array_equal(result, expected)
expected2 = ifft(expected, axis=axis)
out2 = out if dtype is complex else zeros_like(expected2)
result2 = ifft(out, out=out2, axis=axis)
assert result2 is out2
assert_array_equal(result2, expected2)
@pytest.mark.parametrize("axis", [0, 1])
def test_fft_inplace_out(self, axis):
# Test some weirder in-place combinations
y = random((20, 20)) + 1j*random((20, 20))
# Fully in-place.
y1 = y.copy()
expected1 = np.fft.fft(y1, axis=axis)
result1 = np.fft.fft(y1, axis=axis, out=y1)
assert result1 is y1
assert_array_equal(result1, expected1)
# In-place of part of the array; rest should be unchanged.
y2 = y.copy()
out2 = y2[:10] if axis == 0 else y2[:, :10]
expected2 = np.fft.fft(y2, n=10, axis=axis)
result2 = np.fft.fft(y2, n=10, axis=axis, out=out2)
assert result2 is out2
assert_array_equal(result2, expected2)
if axis == 0:
assert_array_equal(y2[10:], y[10:])
else:
assert_array_equal(y2[:, 10:], y[:, 10:])
# In-place of another part of the array.
y3 = y.copy()
y3_sel = y3[5:] if axis == 0 else y3[:, 5:]
out3 = y3[5:15] if axis == 0 else y3[:, 5:15]
expected3 = np.fft.fft(y3_sel, n=10, axis=axis)
result3 = np.fft.fft(y3_sel, n=10, axis=axis, out=out3)
assert result3 is out3
assert_array_equal(result3, expected3)
if axis == 0:
assert_array_equal(y3[:5], y[:5])
assert_array_equal(y3[15:], y[15:])
else:
assert_array_equal(y3[:, :5], y[:, :5])
assert_array_equal(y3[:, 15:], y[:, 15:])
# In-place with n > nin; rest should be unchanged.
y4 = y.copy()
y4_sel = y4[:10] if axis == 0 else y4[:, :10]
out4 = y4[:15] if axis == 0 else y4[:, :15]
expected4 = np.fft.fft(y4_sel, n=15, axis=axis)
result4 = np.fft.fft(y4_sel, n=15, axis=axis, out=out4)
assert result4 is out4
assert_array_equal(result4, expected4)
if axis == 0:
assert_array_equal(y4[15:], y[15:])
else:
assert_array_equal(y4[:, 15:], y[:, 15:])
# Overwrite in a transpose.
y5 = y.copy()
out5 = y5.T
result5 = np.fft.fft(y5, axis=axis, out=out5)
assert result5 is out5
assert_array_equal(result5, expected1)
# Reverse strides.
y6 = y.copy()
out6 = y6[::-1] if axis == 0 else y6[:, ::-1]
result6 = np.fft.fft(y6, axis=axis, out=out6)
assert result6 is out6
assert_array_equal(result6, expected1)
def test_fft_bad_out(self):
x = np.arange(30.)
with pytest.raises(TypeError, match="must be of ArrayType"):
np.fft.fft(x, out="")
with pytest.raises(ValueError, match="has wrong shape"):
np.fft.fft(x, out=np.zeros_like(x).reshape(5, -1))
with pytest.raises(TypeError, match="Cannot cast"):
np.fft.fft(x, out=np.zeros_like(x, dtype=float))
@pytest.mark.parametrize('norm', (None, 'backward', 'ortho', 'forward'))
def test_ifft(self, norm):
x = random(30) + 1j*random(30)
assert_allclose(
x, np.fft.ifft(np.fft.fft(x, norm=norm), norm=norm),
atol=1e-6)
# Ensure we get the correct error message
with pytest.raises(ValueError,
match='Invalid number of FFT data points'):
np.fft.ifft([], norm=norm)
def test_fft2(self):
x = random((30, 20)) + 1j*random((30, 20))
assert_allclose(np.fft.fft(np.fft.fft(x, axis=1), axis=0),
np.fft.fft2(x), atol=1e-6)
assert_allclose(np.fft.fft2(x),
np.fft.fft2(x, norm="backward"), atol=1e-6)
assert_allclose(np.fft.fft2(x) / np.sqrt(30 * 20),
np.fft.fft2(x, norm="ortho"), atol=1e-6)
assert_allclose(np.fft.fft2(x) / (30. * 20.),
np.fft.fft2(x, norm="forward"), atol=1e-6)
def test_ifft2(self):
x = random((30, 20)) + 1j*random((30, 20))
assert_allclose(np.fft.ifft(np.fft.ifft(x, axis=1), axis=0),
np.fft.ifft2(x), atol=1e-6)
assert_allclose(np.fft.ifft2(x),
np.fft.ifft2(x, norm="backward"), atol=1e-6)
assert_allclose(np.fft.ifft2(x) * np.sqrt(30 * 20),
np.fft.ifft2(x, norm="ortho"), atol=1e-6)
assert_allclose(np.fft.ifft2(x) * (30. * 20.),
np.fft.ifft2(x, norm="forward"), atol=1e-6)
def test_fftn(self):
x = random((30, 20, 10)) + 1j*random((30, 20, 10))
assert_allclose(
np.fft.fft(np.fft.fft(np.fft.fft(x, axis=2), axis=1), axis=0),
np.fft.fftn(x), atol=1e-6)
assert_allclose(np.fft.fftn(x),
np.fft.fftn(x, norm="backward"), atol=1e-6)
assert_allclose(np.fft.fftn(x) / np.sqrt(30 * 20 * 10),
np.fft.fftn(x, norm="ortho"), atol=1e-6)
assert_allclose(np.fft.fftn(x) / (30. * 20. * 10.),
np.fft.fftn(x, norm="forward"), atol=1e-6)
def test_ifftn(self):
x = random((30, 20, 10)) + 1j*random((30, 20, 10))
assert_allclose(
np.fft.ifft(np.fft.ifft(np.fft.ifft(x, axis=2), axis=1), axis=0),
np.fft.ifftn(x), atol=1e-6)
assert_allclose(np.fft.ifftn(x),
np.fft.ifftn(x, norm="backward"), atol=1e-6)
assert_allclose(np.fft.ifftn(x) * np.sqrt(30 * 20 * 10),
np.fft.ifftn(x, norm="ortho"), atol=1e-6)
assert_allclose(np.fft.ifftn(x) * (30. * 20. * 10.),
np.fft.ifftn(x, norm="forward"), atol=1e-6)
def test_rfft(self):
x = random(30)
for n in [x.size, 2*x.size]:
for norm in [None, 'backward', 'ortho', 'forward']:
assert_allclose(
np.fft.fft(x, n=n, norm=norm)[:(n//2 + 1)],
np.fft.rfft(x, n=n, norm=norm), atol=1e-6)
assert_allclose(
np.fft.rfft(x, n=n),
np.fft.rfft(x, n=n, norm="backward"), atol=1e-6)
assert_allclose(
np.fft.rfft(x, n=n) / np.sqrt(n),
np.fft.rfft(x, n=n, norm="ortho"), atol=1e-6)
assert_allclose(
np.fft.rfft(x, n=n) / n,
np.fft.rfft(x, n=n, norm="forward"), atol=1e-6)
def test_rfft_even(self):
x = np.arange(8)
n = 4
y = np.fft.rfft(x, n)
assert_allclose(y, np.fft.fft(x[:n])[:n//2 + 1], rtol=1e-14)
def test_rfft_odd(self):
x = np.array([1, 0, 2, 3, -3])
y = np.fft.rfft(x)
assert_allclose(y, np.fft.fft(x)[:3], rtol=1e-14)
def test_irfft(self):
x = random(30)
assert_allclose(x, np.fft.irfft(np.fft.rfft(x)), atol=1e-6)
assert_allclose(x, np.fft.irfft(np.fft.rfft(x, norm="backward"),
norm="backward"), atol=1e-6)
assert_allclose(x, np.fft.irfft(np.fft.rfft(x, norm="ortho"),
norm="ortho"), atol=1e-6)
assert_allclose(x, np.fft.irfft(np.fft.rfft(x, norm="forward"),
norm="forward"), atol=1e-6)
def test_rfft2(self):
x = random((30, 20))
assert_allclose(np.fft.fft2(x)[:, :11], np.fft.rfft2(x), atol=1e-6)
assert_allclose(np.fft.rfft2(x),
np.fft.rfft2(x, norm="backward"), atol=1e-6)
assert_allclose(np.fft.rfft2(x) / np.sqrt(30 * 20),
np.fft.rfft2(x, norm="ortho"), atol=1e-6)
assert_allclose(np.fft.rfft2(x) / (30. * 20.),
np.fft.rfft2(x, norm="forward"), atol=1e-6)
def test_irfft2(self):
x = random((30, 20))
assert_allclose(x, np.fft.irfft2(np.fft.rfft2(x)), atol=1e-6)
assert_allclose(x, np.fft.irfft2(np.fft.rfft2(x, norm="backward"),
norm="backward"), atol=1e-6)
assert_allclose(x, np.fft.irfft2(np.fft.rfft2(x, norm="ortho"),
norm="ortho"), atol=1e-6)
assert_allclose(x, np.fft.irfft2(np.fft.rfft2(x, norm="forward"),
norm="forward"), atol=1e-6)
def test_rfftn(self):
x = random((30, 20, 10))
assert_allclose(np.fft.fftn(x)[:, :, :6], np.fft.rfftn(x), atol=1e-6)
assert_allclose(np.fft.rfftn(x),
np.fft.rfftn(x, norm="backward"), atol=1e-6)
assert_allclose(np.fft.rfftn(x) / np.sqrt(30 * 20 * 10),
np.fft.rfftn(x, norm="ortho"), atol=1e-6)
assert_allclose(np.fft.rfftn(x) / (30. * 20. * 10.),
np.fft.rfftn(x, norm="forward"), atol=1e-6)
# Regression test for gh-27159
x = np.ones((2, 3))
result = np.fft.rfftn(x, axes=(0, 0, 1), s=(10, 20, 40))
assert result.shape == (10, 21)
expected = np.fft.fft(np.fft.fft(np.fft.rfft(x, axis=1, n=40),
axis=0, n=20), axis=0, n=10)
assert expected.shape == (10, 21)
assert_allclose(result, expected, atol=1e-6)
def test_irfftn(self):
x = random((30, 20, 10))
assert_allclose(x, np.fft.irfftn(np.fft.rfftn(x)), atol=1e-6)
assert_allclose(x, np.fft.irfftn(np.fft.rfftn(x, norm="backward"),
norm="backward"), atol=1e-6)
assert_allclose(x, np.fft.irfftn(np.fft.rfftn(x, norm="ortho"),
norm="ortho"), atol=1e-6)
assert_allclose(x, np.fft.irfftn(np.fft.rfftn(x, norm="forward"),
norm="forward"), atol=1e-6)
def test_hfft(self):
x = random(14) + 1j*random(14)
x_herm = np.concatenate((random(1), x, random(1)))
x = np.concatenate((x_herm, x[::-1].conj()))
assert_allclose(np.fft.fft(x), np.fft.hfft(x_herm), atol=1e-6)
assert_allclose(np.fft.hfft(x_herm),
np.fft.hfft(x_herm, norm="backward"), atol=1e-6)
assert_allclose(np.fft.hfft(x_herm) / np.sqrt(30),
np.fft.hfft(x_herm, norm="ortho"), atol=1e-6)
assert_allclose(np.fft.hfft(x_herm) / 30.,
np.fft.hfft(x_herm, norm="forward"), atol=1e-6)
def test_ihfft(self):
x = random(14) + 1j*random(14)
x_herm = np.concatenate((random(1), x, random(1)))
x = np.concatenate((x_herm, x[::-1].conj()))
assert_allclose(x_herm, np.fft.ihfft(np.fft.hfft(x_herm)), atol=1e-6)
assert_allclose(x_herm, np.fft.ihfft(np.fft.hfft(x_herm,
norm="backward"), norm="backward"), atol=1e-6)
assert_allclose(x_herm, np.fft.ihfft(np.fft.hfft(x_herm,
norm="ortho"), norm="ortho"), atol=1e-6)
assert_allclose(x_herm, np.fft.ihfft(np.fft.hfft(x_herm,
norm="forward"), norm="forward"), atol=1e-6)
@pytest.mark.parametrize("op", [np.fft.fftn, np.fft.ifftn,
np.fft.rfftn, np.fft.irfftn])
def test_axes(self, op):
x = random((30, 20, 10))
axes = [(0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), (2, 1, 0)]
for a in axes:
op_tr = op(np.transpose(x, a))
tr_op = np.transpose(op(x, axes=a), a)
assert_allclose(op_tr, tr_op, atol=1e-6)
@pytest.mark.parametrize("op", [np.fft.fftn, np.fft.ifftn,
np.fft.fft2, np.fft.ifft2])
def test_s_negative_1(self, op):
x = np.arange(100).reshape(10, 10)
# should use the whole input array along the first axis
assert op(x, s=(-1, 5), axes=(0, 1)).shape == (10, 5)
@pytest.mark.parametrize("op", [np.fft.fftn, np.fft.ifftn,
np.fft.rfftn, np.fft.irfftn])
def test_s_axes_none(self, op):
x = np.arange(100).reshape(10, 10)
with pytest.warns(match='`axes` should not be `None` if `s`'):
op(x, s=(-1, 5))
@pytest.mark.parametrize("op", [np.fft.fft2, np.fft.ifft2])
def test_s_axes_none_2D(self, op):
x = np.arange(100).reshape(10, 10)
with pytest.warns(match='`axes` should not be `None` if `s`'):
op(x, s=(-1, 5), axes=None)
@pytest.mark.parametrize("op", [np.fft.fftn, np.fft.ifftn,
np.fft.rfftn, np.fft.irfftn,
np.fft.fft2, np.fft.ifft2])
def test_s_contains_none(self, op):
x = random((30, 20, 10))
with pytest.warns(match='array containing `None` values to `s`'):
op(x, s=(10, None, 10), axes=(0, 1, 2))
def test_all_1d_norm_preserving(self):
# verify that round-trip transforms are norm-preserving
x = random(30)
x_norm = np.linalg.norm(x)
n = x.size * 2
func_pairs = [(np.fft.fft, np.fft.ifft),
(np.fft.rfft, np.fft.irfft),
# hfft: order so the first function takes x.size samples
# (necessary for comparison to x_norm above)
(np.fft.ihfft, np.fft.hfft),
]
for forw, back in func_pairs:
for n in [x.size, 2*x.size]:
for norm in [None, 'backward', 'ortho', 'forward']:
tmp = forw(x, n=n, norm=norm)
tmp = back(tmp, n=n, norm=norm)
assert_allclose(x_norm,
np.linalg.norm(tmp), atol=1e-6)
@pytest.mark.parametrize("axes", [(0, 1), (0, 2), None])
@pytest.mark.parametrize("dtype", (complex, float))
@pytest.mark.parametrize("transpose", (True, False))
def test_fftn_out_argument(self, dtype, transpose, axes):
def zeros_like(x):
if transpose:
return np.zeros_like(x.T).T
else:
return np.zeros_like(x)
# tests below only test the out parameter
if dtype is complex:
x = random((10, 5, 6)) + 1j*random((10, 5, 6))
fft, ifft = np.fft.fftn, np.fft.ifftn
else:
x = random((10, 5, 6))
fft, ifft = np.fft.rfftn, np.fft.irfftn
expected = fft(x, axes=axes)
out = zeros_like(expected)
result = fft(x, out=out, axes=axes)
assert result is out
assert_array_equal(result, expected)
expected2 = ifft(expected, axes=axes)
out2 = out if dtype is complex else zeros_like(expected2)
result2 = ifft(out, out=out2, axes=axes)
assert result2 is out2
assert_array_equal(result2, expected2)
@pytest.mark.parametrize("fft", [np.fft.fftn, np.fft.ifftn, np.fft.rfftn])
def test_fftn_out_and_s_interaction(self, fft):
# With s, shape varies, so generally one cannot pass in out.
if fft is np.fft.rfftn:
x = random((10, 5, 6))
else:
x = random((10, 5, 6)) + 1j*random((10, 5, 6))
with pytest.raises(ValueError, match="has wrong shape"):
fft(x, out=np.zeros_like(x), s=(3, 3, 3), axes=(0, 1, 2))
# Except on the first axis done (which is the last of axes).
s = (10, 5, 5)
expected = fft(x, s=s, axes=(0, 1, 2))
out = np.zeros_like(expected)
result = fft(x, s=s, axes=(0, 1, 2), out=out)
assert result is out
assert_array_equal(result, expected)
@pytest.mark.parametrize("s", [(9, 5, 5), (3, 3, 3)])
def test_irfftn_out_and_s_interaction(self, s):
# Since for irfftn, the output is real and thus cannot be used for
# intermediate steps, it should always work.
x = random((9, 5, 6, 2)) + 1j*random((9, 5, 6, 2))
expected = np.fft.irfftn(x, s=s, axes=(0, 1, 2))
out = np.zeros_like(expected)
result = np.fft.irfftn(x, s=s, axes=(0, 1, 2), out=out)
assert result is out
assert_array_equal(result, expected)
@pytest.mark.parametrize(
"dtype",
[np.float32, np.float64, np.complex64, np.complex128])
@pytest.mark.parametrize("order", ["F", 'non-contiguous'])
@pytest.mark.parametrize(
"fft",
[np.fft.fft, np.fft.fft2, np.fft.fftn,
np.fft.ifft, np.fft.ifft2, np.fft.ifftn])
def test_fft_with_order(dtype, order, fft):
# Check that FFT/IFFT produces identical results for C, Fortran and
# non contiguous arrays
rng = np.random.RandomState(42)
X = rng.rand(8, 7, 13).astype(dtype, copy=False)
# See discussion in pull/14178
_tol = 8.0 * np.sqrt(np.log2(X.size)) * np.finfo(X.dtype).eps
if order == 'F':
Y = np.asfortranarray(X)
else:
# Make a non contiguous array
Y = X[::-1]
X = np.ascontiguousarray(X[::-1])
if fft.__name__.endswith('fft'):
for axis in range(3):
X_res = fft(X, axis=axis)
Y_res = fft(Y, axis=axis)
assert_allclose(X_res, Y_res, atol=_tol, rtol=_tol)
elif fft.__name__.endswith(('fft2', 'fftn')):
axes = [(0, 1), (1, 2), (0, 2)]
if fft.__name__.endswith('fftn'):
axes.extend([(0,), (1,), (2,), None])
for ax in axes:
X_res = fft(X, axes=ax)
Y_res = fft(Y, axes=ax)
assert_allclose(X_res, Y_res, atol=_tol, rtol=_tol)
else:
raise ValueError()
@pytest.mark.parametrize("order", ["F", "C"])
@pytest.mark.parametrize("n", [None, 7, 12])
def test_fft_output_order(order, n):
rng = np.random.RandomState(42)
x = rng.rand(10)
x = np.asarray(x, dtype=np.complex64, order=order)
res = np.fft.fft(x, n=n)
assert res.flags.c_contiguous == x.flags.c_contiguous
assert res.flags.f_contiguous == x.flags.f_contiguous
@pytest.mark.skipif(IS_WASM, reason="Cannot start thread")
class TestFFTThreadSafe:
threads = 16
input_shape = (800, 200)
def _test_mtsame(self, func, *args):
def worker(args, q):
q.put(func(*args))
q = queue.Queue()
expected = func(*args)
# Spin off a bunch of threads to call the same function simultaneously
t = [threading.Thread(target=worker, args=(args, q))
for i in range(self.threads)]
[x.start() for x in t]
[x.join() for x in t]
# Make sure all threads returned the correct value
for i in range(self.threads):
assert_array_equal(q.get(timeout=5), expected,
'Function returned wrong value in multithreaded context')
def test_fft(self):
a = np.ones(self.input_shape) * 1+0j
self._test_mtsame(np.fft.fft, a)
def test_ifft(self):
a = np.ones(self.input_shape) * 1+0j
self._test_mtsame(np.fft.ifft, a)
def test_rfft(self):
a = np.ones(self.input_shape)
self._test_mtsame(np.fft.rfft, a)
def test_irfft(self):
a = np.ones(self.input_shape) * 1+0j
self._test_mtsame(np.fft.irfft, a)
def test_irfft_with_n_1_regression():
# Regression test for gh-25661
x = np.arange(10)
np.fft.irfft(x, n=1)
np.fft.hfft(x, n=1)
np.fft.irfft(np.array([0], complex), n=10)
def test_irfft_with_n_large_regression():
# Regression test for gh-25679
x = np.arange(5) * (1 + 1j)
result = np.fft.hfft(x, n=10)
expected = np.array([20., 9.91628173, -11.8819096, 7.1048486,
-6.62459848, 4., -3.37540152, -0.16057669,
1.8819096, -20.86055364])
assert_allclose(result, expected)
@pytest.mark.parametrize("fft", [
np.fft.fft, np.fft.ifft, np.fft.rfft, np.fft.irfft
])
@pytest.mark.parametrize("data", [
np.array([False, True, False]),
np.arange(10, dtype=np.uint8),
np.arange(5, dtype=np.int16),
])
def test_fft_with_integer_or_bool_input(data, fft):
# Regression test for gh-25819
result = fft(data)
float_data = data.astype(np.result_type(data, 1.))
expected = fft(float_data)
assert_array_equal(result, expected)