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https://github.com/bvanroll/college-python-image.git
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from __future__ import division, absolute_import, print_function
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import numpy as np
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from numpy.random import random
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from numpy.testing import (
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run_module_suite, assert_array_almost_equal, assert_array_equal,
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assert_raises,
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)
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import threading
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import sys
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if sys.version_info[0] >= 3:
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import queue
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else:
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import Queue as queue
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def fft1(x):
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L = len(x)
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phase = -2j*np.pi*(np.arange(L)/float(L))
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phase = np.arange(L).reshape(-1, 1) * phase
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return np.sum(x*np.exp(phase), axis=1)
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class TestFFTShift(object):
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def test_fft_n(self):
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assert_raises(ValueError, np.fft.fft, [1, 2, 3], 0)
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class TestFFT1D(object):
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def test_fft(self):
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x = random(30) + 1j*random(30)
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assert_array_almost_equal(fft1(x), np.fft.fft(x))
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assert_array_almost_equal(fft1(x) / np.sqrt(30),
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np.fft.fft(x, norm="ortho"))
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def test_ifft(self):
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x = random(30) + 1j*random(30)
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assert_array_almost_equal(x, np.fft.ifft(np.fft.fft(x)))
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assert_array_almost_equal(
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x, np.fft.ifft(np.fft.fft(x, norm="ortho"), norm="ortho"))
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def test_fft2(self):
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x = random((30, 20)) + 1j*random((30, 20))
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assert_array_almost_equal(np.fft.fft(np.fft.fft(x, axis=1), axis=0),
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np.fft.fft2(x))
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assert_array_almost_equal(np.fft.fft2(x) / np.sqrt(30 * 20),
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np.fft.fft2(x, norm="ortho"))
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def test_ifft2(self):
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x = random((30, 20)) + 1j*random((30, 20))
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assert_array_almost_equal(np.fft.ifft(np.fft.ifft(x, axis=1), axis=0),
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np.fft.ifft2(x))
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assert_array_almost_equal(np.fft.ifft2(x) * np.sqrt(30 * 20),
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np.fft.ifft2(x, norm="ortho"))
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def test_fftn(self):
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x = random((30, 20, 10)) + 1j*random((30, 20, 10))
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assert_array_almost_equal(
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np.fft.fft(np.fft.fft(np.fft.fft(x, axis=2), axis=1), axis=0),
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np.fft.fftn(x))
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assert_array_almost_equal(np.fft.fftn(x) / np.sqrt(30 * 20 * 10),
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np.fft.fftn(x, norm="ortho"))
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def test_ifftn(self):
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x = random((30, 20, 10)) + 1j*random((30, 20, 10))
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assert_array_almost_equal(
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np.fft.ifft(np.fft.ifft(np.fft.ifft(x, axis=2), axis=1), axis=0),
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np.fft.ifftn(x))
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assert_array_almost_equal(np.fft.ifftn(x) * np.sqrt(30 * 20 * 10),
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np.fft.ifftn(x, norm="ortho"))
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def test_rfft(self):
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x = random(30)
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for n in [x.size, 2*x.size]:
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for norm in [None, 'ortho']:
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assert_array_almost_equal(
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np.fft.fft(x, n=n, norm=norm)[:(n//2 + 1)],
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np.fft.rfft(x, n=n, norm=norm))
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assert_array_almost_equal(np.fft.rfft(x, n=n) / np.sqrt(n),
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np.fft.rfft(x, n=n, norm="ortho"))
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def test_irfft(self):
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x = random(30)
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assert_array_almost_equal(x, np.fft.irfft(np.fft.rfft(x)))
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assert_array_almost_equal(
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x, np.fft.irfft(np.fft.rfft(x, norm="ortho"), norm="ortho"))
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def test_rfft2(self):
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x = random((30, 20))
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assert_array_almost_equal(np.fft.fft2(x)[:, :11], np.fft.rfft2(x))
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assert_array_almost_equal(np.fft.rfft2(x) / np.sqrt(30 * 20),
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np.fft.rfft2(x, norm="ortho"))
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def test_irfft2(self):
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x = random((30, 20))
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assert_array_almost_equal(x, np.fft.irfft2(np.fft.rfft2(x)))
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assert_array_almost_equal(
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x, np.fft.irfft2(np.fft.rfft2(x, norm="ortho"), norm="ortho"))
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def test_rfftn(self):
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x = random((30, 20, 10))
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assert_array_almost_equal(np.fft.fftn(x)[:, :, :6], np.fft.rfftn(x))
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assert_array_almost_equal(np.fft.rfftn(x) / np.sqrt(30 * 20 * 10),
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np.fft.rfftn(x, norm="ortho"))
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def test_irfftn(self):
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x = random((30, 20, 10))
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assert_array_almost_equal(x, np.fft.irfftn(np.fft.rfftn(x)))
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assert_array_almost_equal(
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x, np.fft.irfftn(np.fft.rfftn(x, norm="ortho"), norm="ortho"))
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def test_hfft(self):
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x = random(14) + 1j*random(14)
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x_herm = np.concatenate((random(1), x, random(1)))
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x = np.concatenate((x_herm, x[::-1].conj()))
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assert_array_almost_equal(np.fft.fft(x), np.fft.hfft(x_herm))
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assert_array_almost_equal(np.fft.hfft(x_herm) / np.sqrt(30),
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np.fft.hfft(x_herm, norm="ortho"))
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def test_ihttf(self):
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x = random(14) + 1j*random(14)
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x_herm = np.concatenate((random(1), x, random(1)))
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x = np.concatenate((x_herm, x[::-1].conj()))
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assert_array_almost_equal(x_herm, np.fft.ihfft(np.fft.hfft(x_herm)))
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assert_array_almost_equal(
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x_herm, np.fft.ihfft(np.fft.hfft(x_herm, norm="ortho"),
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norm="ortho"))
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def test_all_1d_norm_preserving(self):
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# verify that round-trip transforms are norm-preserving
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x = random(30)
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x_norm = np.linalg.norm(x)
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n = x.size * 2
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func_pairs = [(np.fft.fft, np.fft.ifft),
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(np.fft.rfft, np.fft.irfft),
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# hfft: order so the first function takes x.size samples
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# (necessary for comparison to x_norm above)
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(np.fft.ihfft, np.fft.hfft),
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]
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for forw, back in func_pairs:
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for n in [x.size, 2*x.size]:
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for norm in [None, 'ortho']:
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tmp = forw(x, n=n, norm=norm)
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tmp = back(tmp, n=n, norm=norm)
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assert_array_almost_equal(x_norm,
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np.linalg.norm(tmp))
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class TestFFTThreadSafe(object):
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threads = 16
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input_shape = (800, 200)
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def _test_mtsame(self, func, *args):
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def worker(args, q):
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q.put(func(*args))
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q = queue.Queue()
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expected = func(*args)
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# Spin off a bunch of threads to call the same function simultaneously
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t = [threading.Thread(target=worker, args=(args, q))
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for i in range(self.threads)]
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[x.start() for x in t]
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[x.join() for x in t]
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# Make sure all threads returned the correct value
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for i in range(self.threads):
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assert_array_equal(q.get(timeout=5), expected,
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'Function returned wrong value in multithreaded context')
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def test_fft(self):
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a = np.ones(self.input_shape) * 1+0j
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self._test_mtsame(np.fft.fft, a)
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def test_ifft(self):
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a = np.ones(self.input_shape) * 1+0j
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self._test_mtsame(np.fft.ifft, a)
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def test_rfft(self):
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a = np.ones(self.input_shape)
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self._test_mtsame(np.fft.rfft, a)
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def test_irfft(self):
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a = np.ones(self.input_shape) * 1+0j
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self._test_mtsame(np.fft.irfft, a)
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if __name__ == "__main__":
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run_module_suite()
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"""Test functions for fftpack.helper module
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Copied from fftpack.helper by Pearu Peterson, October 2005
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"""
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from __future__ import division, absolute_import, print_function
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import numpy as np
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from numpy.testing import (
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run_module_suite, assert_array_almost_equal, assert_equal,
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)
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from numpy import fft
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from numpy import pi
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from numpy.fft.helper import _FFTCache
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class TestFFTShift(object):
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def test_definition(self):
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x = [0, 1, 2, 3, 4, -4, -3, -2, -1]
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y = [-4, -3, -2, -1, 0, 1, 2, 3, 4]
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assert_array_almost_equal(fft.fftshift(x), y)
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assert_array_almost_equal(fft.ifftshift(y), x)
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x = [0, 1, 2, 3, 4, -5, -4, -3, -2, -1]
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y = [-5, -4, -3, -2, -1, 0, 1, 2, 3, 4]
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assert_array_almost_equal(fft.fftshift(x), y)
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assert_array_almost_equal(fft.ifftshift(y), x)
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def test_inverse(self):
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for n in [1, 4, 9, 100, 211]:
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x = np.random.random((n,))
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assert_array_almost_equal(fft.ifftshift(fft.fftshift(x)), x)
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def test_axes_keyword(self):
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freqs = [[0, 1, 2], [3, 4, -4], [-3, -2, -1]]
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shifted = [[-1, -3, -2], [2, 0, 1], [-4, 3, 4]]
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assert_array_almost_equal(fft.fftshift(freqs, axes=(0, 1)), shifted)
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assert_array_almost_equal(fft.fftshift(freqs, axes=0),
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fft.fftshift(freqs, axes=(0,)))
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assert_array_almost_equal(fft.ifftshift(shifted, axes=(0, 1)), freqs)
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assert_array_almost_equal(fft.ifftshift(shifted, axes=0),
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fft.ifftshift(shifted, axes=(0,)))
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class TestFFTFreq(object):
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def test_definition(self):
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x = [0, 1, 2, 3, 4, -4, -3, -2, -1]
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assert_array_almost_equal(9*fft.fftfreq(9), x)
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assert_array_almost_equal(9*pi*fft.fftfreq(9, pi), x)
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x = [0, 1, 2, 3, 4, -5, -4, -3, -2, -1]
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assert_array_almost_equal(10*fft.fftfreq(10), x)
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assert_array_almost_equal(10*pi*fft.fftfreq(10, pi), x)
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class TestRFFTFreq(object):
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def test_definition(self):
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x = [0, 1, 2, 3, 4]
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assert_array_almost_equal(9*fft.rfftfreq(9), x)
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assert_array_almost_equal(9*pi*fft.rfftfreq(9, pi), x)
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x = [0, 1, 2, 3, 4, 5]
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assert_array_almost_equal(10*fft.rfftfreq(10), x)
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assert_array_almost_equal(10*pi*fft.rfftfreq(10, pi), x)
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class TestIRFFTN(object):
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def test_not_last_axis_success(self):
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ar, ai = np.random.random((2, 16, 8, 32))
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a = ar + 1j*ai
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axes = (-2,)
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# Should not raise error
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fft.irfftn(a, axes=axes)
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class TestFFTCache(object):
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def test_basic_behaviour(self):
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c = _FFTCache(max_size_in_mb=1, max_item_count=4)
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# Put
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c.put_twiddle_factors(1, np.ones(2, dtype=np.float32))
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c.put_twiddle_factors(2, np.zeros(2, dtype=np.float32))
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# Get
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assert_array_almost_equal(c.pop_twiddle_factors(1),
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np.ones(2, dtype=np.float32))
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assert_array_almost_equal(c.pop_twiddle_factors(2),
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np.zeros(2, dtype=np.float32))
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# Nothing should be left.
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assert_equal(len(c._dict), 0)
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# Now put everything in twice so it can be retrieved once and each will
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# still have one item left.
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for _ in range(2):
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c.put_twiddle_factors(1, np.ones(2, dtype=np.float32))
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c.put_twiddle_factors(2, np.zeros(2, dtype=np.float32))
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assert_array_almost_equal(c.pop_twiddle_factors(1),
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np.ones(2, dtype=np.float32))
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assert_array_almost_equal(c.pop_twiddle_factors(2),
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np.zeros(2, dtype=np.float32))
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assert_equal(len(c._dict), 2)
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def test_automatic_pruning(self):
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# That's around 2600 single precision samples.
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c = _FFTCache(max_size_in_mb=0.01, max_item_count=4)
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c.put_twiddle_factors(1, np.ones(200, dtype=np.float32))
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c.put_twiddle_factors(2, np.ones(200, dtype=np.float32))
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assert_equal(list(c._dict.keys()), [1, 2])
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# This is larger than the limit but should still be kept.
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c.put_twiddle_factors(3, np.ones(3000, dtype=np.float32))
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assert_equal(list(c._dict.keys()), [1, 2, 3])
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# Add one more.
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c.put_twiddle_factors(4, np.ones(3000, dtype=np.float32))
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# The other three should no longer exist.
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assert_equal(list(c._dict.keys()), [4])
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# Now test the max item count pruning.
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c = _FFTCache(max_size_in_mb=0.01, max_item_count=2)
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c.put_twiddle_factors(2, np.empty(2))
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c.put_twiddle_factors(1, np.empty(2))
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# Can still be accessed.
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assert_equal(list(c._dict.keys()), [2, 1])
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c.put_twiddle_factors(3, np.empty(2))
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# 1 and 3 can still be accessed - c[2] has been touched least recently
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# and is thus evicted.
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assert_equal(list(c._dict.keys()), [1, 3])
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# One last test. We will add a single large item that is slightly
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# bigger then the cache size. Some small items can still be added.
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c = _FFTCache(max_size_in_mb=0.01, max_item_count=5)
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c.put_twiddle_factors(1, np.ones(3000, dtype=np.float32))
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c.put_twiddle_factors(2, np.ones(2, dtype=np.float32))
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c.put_twiddle_factors(3, np.ones(2, dtype=np.float32))
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c.put_twiddle_factors(4, np.ones(2, dtype=np.float32))
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assert_equal(list(c._dict.keys()), [1, 2, 3, 4])
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# One more big item. This time it is 6 smaller ones but they are
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# counted as one big item.
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for _ in range(6):
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c.put_twiddle_factors(5, np.ones(500, dtype=np.float32))
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# '1' no longer in the cache. Rest still in the cache.
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assert_equal(list(c._dict.keys()), [2, 3, 4, 5])
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# Another big item - should now be the only item in the cache.
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c.put_twiddle_factors(6, np.ones(4000, dtype=np.float32))
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assert_equal(list(c._dict.keys()), [6])
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if __name__ == "__main__":
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run_module_suite()
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