FFTW
Fast Fourier Transforms
C Calling Examples

FFTW is a directory of C programs which illustate the use of the FFTW Fast Fourier Transform library, by Matteo Frigo and Steven Johnson.

The FFTW library can compute the discrete Fourier transform of:

• complex data;
• real data;
• even-symmetric real data (cosine transform);
• odd-symmetric real data (sine transform);

The length of the data is not required to be a power of 2. Any length of data can be processed.

The data is not restricted to 1 dimensional vectors. FFTW can handle data that is 2 or 3 dimensional. In fact, the program can handle data with any dimensionality.

Interested users should go to the FFTW home page: http://www.fftw.org/ which contains the current source code, examples, and documentation.

Usage:

At link time, you must include the FFTW library. Depending on where this library is installed, an appropriate command might be

        gcc myprog.c -lfftw
      

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Non-free licenses may also be purchased from MIT, for users who do not want their programs protected by the GPL.

Languages:

FFTW examples are available in a C version and a FORTRAN90 version.

Related Data and Programs:

FFTPACK4, a C library which implements the Fast Fourier Transform (FFT) by Paul Swarztrauber and Dick Valent, translated by Andrew Fernandes;

FFTPACK5, a FORTRAN90 library which implements the Fast Fourier Transform by Paul Swarztrauber and Dick Valent;

GROMACS, examples which illustrate the use of a molecular dynamics package which uses the FFTW library.

GSL, a C++ library which includes a number of FFT routines.

NMS, a FORTRAN90 library which includes a number of FFT routines.

SFTPACK, a C library which implements the "slow" Fourier transform, intended as a teaching tool and comparison with the fast Fourier transform.

Author:

Matteo Frigo, Steven Johnson

Reference:

1. William Briggs, Van Emden Henson,
   The DFT: An Owner's Manual for the Discrete Fourier Transform,
   SIAM, 1995,
   ISBN13: 978-0-898713-42-8,
   LC: QA403.5.B75.
2. Elbert Brigham,
   The Fast Fourier Transform and Its Applications,
   Prentice-Hall, 1988,
   ISBN: 0133075052,
   LC: QA403.B74.
3. Matteo Frigo and Steven Johnson,
   User Manual for FFTW.
   (Available from the FFTW web site)

Examples and Tests:

• fftw_test.c, a sample calling program.
• fftw_test.txt, the output file.

You can go up one level to the C source codes.