cfftm1di(3F)

NAME
     cfftm1di, zfftm1di - initialize the coefficient array for complex-to-
     complex Multiple 1D FFT modules.

SYNOPSYS
     FORTRAN SPECIFICATION
     subroutine CFFTM1DI( n, coeff )
     integer                  n
     complex             coeff(n+15)

     subroutine ZFFTM1DI( n, coeff )
     integer                  n
     double complex      coeff(n+15)

     C SPECIFICATION
     #include <fft.h>
     complex *cfftm1di( int n, complex *coeff);

     zomplex *zfftm1di( int n, zomplex *coeff);


DESCRIPTION
     Initialize the coefficient array which is used in the Multiple 1D FFT
     modules.  This array contains the different twiddle factors and the
     factorization of N into prime numbers.
     As the FFT modules cfftm1d or zfftm1d only read the coeff array, it may
     be reused as long as necessary once it has been initialized.

     In C, if ptr is NULL, cfftm1di or zfftm1di returns a pointer to an
     allocated buffer.

     CFFTM1DI should be used to initialize the coefficient array before any
     call to CFFTM1D
     ZFFTM1DI should be used to initialize the coefficient array before any
     call to ZFFTM1D

PARAMETERS
     N - Integer. Specifies the length of the sequence to be transformed.
     Unchanged on exit.

     COEFF - Array (C or Fortran) or NULL pointer(C).

Example of Calling Sequence
     Initializing a coefficient array for complex-to-complex FFTs of size 200.

     Fortran :
          complex coeff(200+15)
          call cfftm1di( 200, coeff)

     C :
          #include <fft.h>
          complex *coeff;
         coeff = cfftm1di( 200, NULL);

SEE ALSO
          fft, cfftm1d, zfftm1d