CFFT2(3F)

NAME
     CFFT2 - Calculate a complex-to-complex Fourier synthesis/analysis.

DESCRIPTION
     A subroutine that calculates a Fourier synthesis if the sign of IX is
     negative and a Fourier analysis if the sign of IX is positive.

      Call from FORTRAN:

            CALL CFFT2(init,ix,n,x,work,y)

          init  <>0  Generates sine and cosine tables in WORK
                = 0  Calculates Fourier transforms using sine and
                   cosine tables of previous call.
          ix    > 0  Calculates Fourier analysis
                < 0  Calculates Fourier synthesis.
          n     Size of Fourier transform; 2**m where 2<=m for the
                CRAY-1.
          x     Input vector.  Vector of n complex values.
          work  Working storage.  Vector of (5/2)n complex values.
          y     Result vector.  Vector of n complex values.

     For equations and other additional information, see the CRAY-1 Computer
     Systems - Library Reference Manual, SR-0014, pages 4-51 to 4-52.