text: """
  =========================================================
  Legacy discrete Fourier transforms (:mod:`scipy.fftpack`)
  =========================================================
  
  .. warning::
  
     This submodule is now considered 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 - Two dimensional FFT
     ifft2 - Two dimensional inverse FFT
     fftn - n-dimensional FFT
     ifftn - n-dimensional inverse FFT
     rfft - FFT of strictly real-valued sequence
     irfft - Inverse of rfft
     dct - Discrete cosine transform
     idct - Inverse discrete cosine transform
     dctn - n-dimensional Discrete cosine transform
     idctn - n-dimensional Inverse discrete cosine transform
     dst - Discrete sine transform
     idst - Inverse discrete sine transform
     dstn - n-dimensional Discrete sine transform
     idstn - n-dimensional 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
  
  """
  
  from __future__ import division, print_function, absolute_import
  
  
  __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 *
  
  from scipy._lib._testutils import PytestTester
  test = PytestTester(__name__)
  del PytestTester
  