#!/usr/bin/env python
# Copied from fftpack.helper by Pearu Peterson, October 2005
""" Test functions for fftpack.helper module
"""
import sys
from numpy.testing import *
set_package_path()
from numpy.fft import fftshift,ifftshift,fftfreq
del sys.path[0]
from numpy import pi
def random(size):
return rand(*size)
class TestFFTShift(NumpyTestCase):
def check_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 check_inverse(self):
for n in [1,4,9,100,211]:
x = random((n,))
assert_array_almost_equal(ifftshift(fftshift(x)),x)
class TestFFTFreq(NumpyTestCase):
def check_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)
if __name__ == "__main__":
NumpyTest().run()
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