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FFTPACK

FFTPACK is a package of Fortran-77 subroutines for the Fast Fourier Transform of periodic and other symmetric sequences developed by Paul N. Swarztrauber from the National Center for Atmospheric Research in Boulder, Colorado. The project was sponsored by the National Science Foundation.

The subroutines are transferrable by WWW and FTP from the Netlib site:

http://www.netlib.org/

There are 12 subroutines in the package, plus 7 auxiliary subroutines, which serve to initialize other subroutines, 19 subroutines in total. The essential subroutines are as follows:

rfftf
forward transform of a real periodic sequence
rfftb
backward transform of a real coefficient array
ezfftf
a simplified real periodic forward transform
ezfftb
a simplified real periodic backward transform
sint
sine transform of a real odd sequence
cost
cosine transform of a real even sequence
sinqf
forward sine transform with odd wave numbers
sinqb
unnormalized inverse of sinqf
cosqf
forward cosine transform with odd wave numbers
cosqb
unnormalized inverse of cosqf
cfftf
forward transform of a complex periodic sequence
cfftb
unnormalized inverse of cfftf

See, e.g.,

http://beige.ucs.indiana.edu/FFTPACK/doc
for more information about those routines.


next up previous index
Next: Eigensystems Up: Spectral Methods Previous: A Discrete Formulation of
Zdzislaw Meglicki
2001-02-26