General Purpose FFT (Fast Fourier Transform) Package

Files
    fft2f.c    : FFT Package in C       - Easy Version
    fft2f.f    : FFT Package in Fortran - Easy Version
    fft2ft.c   : Test Program of "fft2f.c"
    fft2ft.f   : Test Program of "fft2f.f"
    fft4f.c    : FFT Package in C       - Normal Version
    fft4f.f    : FFT Package in Fortran - Normal Version
    fft4g.c    : FFT Package in C       - Fast Version
    fft4g.f    : FFT Package in Fortran - Fast Version
    fft4xt.c   : Test Program of "fft4*.c"
    fft4xt.f   : Test Program of "fft4*.f"
    fftxx.doc  : Document of "fft*.*"
    fftxxj.doc : Document of "fft*.*" (Japanese)

Routines in the Package
    cdft: Complex Discrete Fourier Transform
    rdft: Real Discrete Fourier Transform
    ddct: Discrete Cosine Transform
    ddst: Discrete Sine Transform
    dfct: Cosine Transform of RDFT (Real Symmetric DFT)
    dfst: Sine Transform of RDFT (Real Anti-symmetric DFT)

Usage
    Brief explanations are in block comments of each packages.
    The examples are given in the test programs.

Copyright
    Copyright(C) 1996, 1997 Takuya OOURA
    (email: ooura@mmm.t.u-tokyo.ac.jp).
    You may use, copy, modify this code for any purpose and 
    without fee. You may distribute this ORIGINAL package.

