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

NAME

cfft3b - compute a periodic sequence from its Fourier coefficients. The FFT operations are unnormalized, so a call of CFFT3F followed by a call of CFFT3B will multiply the input sequence by M*N*K.

SYNOPSIS

  SUBROUTINE CFFT3B( M, N, K, A, LDA, LD2A, WORK, LWORK)
  COMPLEX A(LDA,LD2A,*)
  INTEGER M, N, K, LDA, LD2A, LWORK
  REAL WORK(*)

  SUBROUTINE CFFT3B_64( M, N, K, A, LDA, LD2A, WORK, LWORK)
  COMPLEX A(LDA,LD2A,*)
  INTEGER*8 M, N, K, LDA, LD2A, LWORK
  REAL WORK(*)

F95 INTERFACE

  SUBROUTINE FFT3B( [M], [N], [K], A, [LDA], LD2A, WORK, LWORK)
  COMPLEX, DIMENSION(:,:,:) :: A
  INTEGER :: M, N, K, LDA, LD2A, LWORK
  REAL, DIMENSION(:) :: WORK

  SUBROUTINE FFT3B_64( [M], [N], [K], A, [LDA], LD2A, WORK, LWORK)
  COMPLEX, DIMENSION(:,:,:) :: A
  INTEGER(8) :: M, N, K, LDA, LD2A, LWORK
  REAL, DIMENSION(:) :: WORK

C INTERFACE

#include <sunperf.h>

void cfft3b(int m, int n, int k, complex *a, int lda, int ld2a, float *work, int lwork);

void cfft3b_64(long m, long n, long k, complex *a, long lda, long ld2a, float *work, long lwork);

ARGUMENTS

• M (input)
  Number of rows to be transformed. These subroutines are most efficient when M is a product of small primes. M > = 0.

• N (input)
  Number of columns to be transformed. These subroutines are most efficient when N is a product of small primes. N > = 0.

• K (input)
  Number of planes to be transformed. These subroutines are most efficient when K is a product of small primes. K > = 0.

• A (input/output)
  On entry, a three-dimensional array A(LDA,LD2A,K) that contains the sequences to be transformed.

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

• LD2A (input)
  Second dimension of the array containing the data to be transformed. LD2A > = N.

• WORK (input)
  On input, workspace WORK must have been initialized by CFFT3I.

• LWORK (input)
  The dimension of the array WORK. LWORK > = (4*(M + N + K) + 45).