sdfftm1du(3F)

dfftm1du, sfftm1du - Multiple 1D, Real to Complex Fast Fourier Transform.

As shipped in IRIX 6.5.15. Unchanged since IRIX 6.5.

NAME
     dfftm1du, sfftm1du - Multiple 1D, Real to Complex Fast Fourier Transform.

FORTRAN SPECIFICATION
     subroutine DFFTM1DU( job, n, p, sequence, inc, lda, workspace )
     integer             job, n, p, inc, lda
     double precision    sequence(lda,*), workspace(*)

     subroutine SFFTM1DU( job, n, p, sequence, inc, lda, workspace )
     integer             job, n, p, inc, lda
     real                sequence(lda,*), workspace(*)


C SPECIFICATION
     int        dfftm1du( int job, int n, int p,
                         double *sequence, int inc, int lda,
                         double *workspace)

     int        sfftm1du( int job, int n, int p,
                         float  *sequence, int inc, int lda,
                         float  *workspace)




DESCRIPTION
     DFFTM1DU and SFFTM1DU compute the complex Fourier transform of P real
     periodic sequences of N samples each.

     NOTE: These routines are provided only for compatibility with previous
     releases of complib.

PARAMETERS
     JOB - INTEGER
     On entry specifies whether to perform a forward or backward Fast Fourier
     Transform:
         JOB = -1,  forward FFT
         JOB =  1,  backward FFT Unchanged on exit.

     N - INTEGER.
     On entry, N specifies the number of elements in each sequence.  Unchanged
     on exit.

     P - INTEGER.
     On entry, P specifies the number of sequences.  Unchanged on exit.

     SEQUENCE - Array.
     Array of DIMENSION ( LDA, p ).  Array containing the (lda*p) elements for
     the FFT.  On exit, SEQUENCE is overwritten by its transform.
     INC - INTEGER.
     Increment between two consecutive elements of the sequence.  Unchanged on
     exit.

     LDA - INTEGER.
     On entry, LDA specifies the first dimension of the array SEQUENCE as
     declared in the calling (sub)program. LDA must be at least max( 1,
     2*((N1+2)/2) ).  Unchanged on exit.

     WORKSPACE - Array.
     Array of dimension at least ( N + 15  ).  Array containing the
     Sines/Cosines and factorization of N.  WORKSPACE needs to be initialized
     by a call to sfftm1dui or dfftm1dui.


SEE ALSO
     o32fft