Contents

• NAME
• SYNOPSIS
  • F95 INTERFACE
  • C INTERFACE
• ARGUMENTS

NAME

     zfft2f - compute the  Fourier  coefficients  of  a  periodic
     sequence.  The FFT operations are unnormalized, so a call of
     ZFFT2F followed by a call of ZFFT2B will multiply the  input
     sequence by M*N.

SYNOPSIS

     SUBROUTINE ZFFT2F(M, N, A, LDA, WORK, LWORK)

     DOUBLE COMPLEX A(LDA,*)
     INTEGER M, N, LDA, LWORK
     DOUBLE PRECISION WORK(*)

     SUBROUTINE ZFFT2F_64(M, N, A, LDA, WORK, LWORK)

     DOUBLE COMPLEX A(LDA,*)
     INTEGER*8 M, N, LDA, LWORK
     DOUBLE PRECISION WORK(*)

  F95 INTERFACE
     SUBROUTINE FFT2F([M], [N], A, [LDA], WORK, LWORK)

     COMPLEX(8), DIMENSION(:,:) :: A
     INTEGER :: M, N, LDA, LWORK
     REAL(8), DIMENSION(:) :: WORK

     SUBROUTINE FFT2F_64([M], [N], A, [LDA], WORK, LWORK)

     COMPLEX(8), DIMENSION(:,:) :: A
     INTEGER(8) :: M, N, LDA, LWORK
     REAL(8), DIMENSION(:) :: WORK

  C INTERFACE
     #include <sunperf.h>

     void zfft2f(int m, int n, doublecomplex *a, int lda,  double
               *work, int lwork);

     void zfft2f_64(long m, long n, doublecomplex *a,  long  lda,
               double *work, long lwork);

ARGUMENTS

     M (input) Number of rows to be transformed.   These  subrou-
               tines  are  most  efficient when M is a product of
               small primes.  M >= 0.
     N (input) Number of columns to be transformed.   These  sub-
               routines are most efficient when N is a product of
               small primes.  N >= 0.

     A (input/output)
               On entry, a two-dimensional array A(M,N) that con-
               tains the sequences to be transformed.

     LDA (input)
               Leading dimension of the array containing the data
               to be transformed.  LDA >= M.

     WORK (input)
               On input, workspace WORK must have  been  initial-
               ized by ZFFT2I.

     LWORK (input)
               The dimension of the array WORK.  LWORK >= (4 * (M
               + N) + 30)