# fftdoc.f

          SUBROUTINE FFTDOC
    C***BEGIN PROLOGUE  FFTDOC
    C***PURPOSE  Documentation for FFTPACK, a collection of Fast Fourier
    C            Transform routines.
    C***LIBRARY   SLATEC
    C***CATEGORY  J1, Z
    C***TYPE      ALL (FFTDOC-A)
    C***KEYWORDS  DOCUMENTATION, FAST FOURIER TRANSFORM, FFT
    C***AUTHOR  Swarztrauber, P. N., (NCAR)
    C***DESCRIPTION
    C
    C     * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
    C                       Version 3  June 1979
    C
    C          A Package of Fortran Subprograms for The Fast Fourier
    C           Transform of Periodic and Other Symmetric Sequences
    C                              By
    C                       Paul N Swarztrauber
    C
    C    National Center For Atmospheric Research, Boulder, Colorado 80307
    C        which is sponsored by the National Science Foundation
    C
    C     * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
    C
    C     This package consists of programs which perform Fast Fourier
    C     Transforms for both complex and real periodic sequences and
    C     certain other symmetric sequences that are listed below.
    C
    C     1.   RFFTI     Initialize RFFTF and RFFTB
    C     2.   RFFTF     Forward transform of a real periodic sequence
    C     3.   RFFTB     Backward transform of a real coefficient array
    C
    C     4.   EZFFTI    Initialize EZFFTF and EZFFTB
    C     5.   EZFFTF    A simplified real periodic forward transform
    C     6.   EZFFTB    A simplified real periodic backward transform
    C
    C     7.   SINTI     Initialize SINT
    C     8.   SINT      Sine transform of a real odd sequence
    C
    C     9.   COSTI     Initialize COST
    C     10.  COST      Cosine transform of a real even sequence
    C
    C     11.  SINQI     Initialize SINQF and SINQB
    C     12.  SINQF     Forward sine transform with odd wave numbers
    C     13.  SINQB     Unnormalized inverse of SINQF
    C
    C     14.  COSQI     Initialize COSQF and COSQB
    C     15.  COSQF     Forward cosine transform with odd wave numbers
    C     16.  COSQB     Unnormalized inverse of COSQF
    C
    C     17.  CFFTI     Initialize CFFTF and CFFTB
    C     18.  CFFTF     Forward transform of a complex periodic sequence
    C     19.  CFFTB     Unnormalized inverse of CFFTF
    C
    C***REFERENCES  (NONE)
    C***ROUTINES CALLED  (NONE)
    C***REVISION HISTORY  (YYMMDD)
    C   780201  DATE WRITTEN
    C   861211  REVISION DATE from Version 3.2
    C   891214  Prologue converted to Version 4.0 format.  (BAB)
    C   900723  PURPOSE section revised.  (WRB)
    C***END PROLOGUE  FFTDOC