In [2]:

    

%run ../common.ipynb


    

    




Populating the interactive namespace from numpy and matplotlib

In [3]:

    

image = imread('../MP.tiff')


    

In [4]:

    

fft2?


    

In [7]:

    

%time numpy_F = fft2(image)


    

    




CPU times: user 32.2 s, sys: 153 ms, total: 32.3 s
Wall time: 32.4 s

In [6]:

    

import pyfftw


    

In [18]:

    

pyfftw.interfaces.numpy_fft.fft2?


    

In [19]:

    

%time fftw_F = pyfftw.interfaces.numpy_fft.fft2(image)


    

    




CPU times: user 9.12 s, sys: 157 ms, total: 9.27 s
Wall time: 9.28 s

In [32]:

    

numpy.array_equal(numpy_F, fftw_F)


    

    
Out[32]:





False

In [22]:

    

numpy.allclose(numpy_F, fftw_F)


    

    
Out[22]:





True

In [26]:

    

imshow(log(abs(fftshift(numpy_F))))


    

    
Out[26]:





(<matplotlib.figure.Figure at 0x11e7888d0>,
 <matplotlib.axes._subplots.AxesSubplot at 0x1265f36d0>,
 <matplotlib.image.AxesImage at 0x12661a190>)






    

In [27]:

    

imshow(log(abs(fftshift(fftw_F))))


    

    
Out[27]:





(<matplotlib.figure.Figure at 0x114c1e590>,
 <matplotlib.axes._subplots.AxesSubplot at 0x126719c90>,
 <matplotlib.image.AxesImage at 0x1267a7b90>)






    

In [33]:

    

# enable cache - http://hgomersall.github.io/pyFFTW/sphinx/tutorial.html#caveat
pyfftw.interfaces.cache.enable()


    

In [35]:

    

# now in cache
%time fftw_F = pyfftw.interfaces.numpy_fft.fft2(image)


    

    




CPU times: user 671 ms, sys: 50.9 ms, total: 722 ms
Wall time: 720 ms

In [36]:

    

pyfftw.interfaces.cache.disable()


    

In [37]:

    

%time fftw_F = pyfftw.interfaces.numpy_fft.fft2(image)


    

    




CPU times: user 684 ms, sys: 33.3 ms, total: 717 ms
Wall time: 716 ms

In [38]:

    

pyfftw.interfaces.cache.enable()


    

In [50]:

    

%time F = pyfftw.interfaces.numpy_fft.fft2(pyfftw.n_byte_align(imread('../MP.tiff'), 16, dtype='uint8'))


    

    




CPU times: user 687 ms, sys: 95.4 ms, total: 783 ms
Wall time: 798 ms

In [44]:

    

F.shape


    

    
Out[44]:





(2111, 2198)

In [45]:

    

pyfftw.n_byte_align_empty?


    

In [46]:

    

pyfftw.n_byte_align?