Contents
zfft3b - compute a periodic sequence from its Fourier coef-
ficients. The FFT operations are unnormalized, so a call of
ZFFT3F followed by a call of ZFFT3B will multiply the input
sequence by M*N*K.
SUBROUTINE ZFFT3B(M, N, K, A, LDA, LD2A, WORK, LWORK)
DOUBLE COMPLEX A(LDA,LD2A,*)
INTEGER M, N, K, LDA, LD2A, LWORK
DOUBLE PRECISION WORK(*)
SUBROUTINE ZFFT3B_64(M, N, K, A, LDA, LD2A, WORK, LWORK)
DOUBLE COMPLEX A(LDA,LD2A,*)
INTEGER*8 M, N, K, LDA, LD2A, LWORK
DOUBLE PRECISION WORK(*)
F95 INTERFACE
SUBROUTINE FFT3B([M], [N], [K], A, [LDA], LD2A, WORK, LWORK)
COMPLEX(8), DIMENSION(:,:,:) :: A
INTEGER :: M, N, K, LDA, LD2A, LWORK
REAL(8), DIMENSION(:) :: WORK
SUBROUTINE FFT3B_64([M], [N], [K], A, [LDA], LD2A, WORK, LWORK)
COMPLEX(8), DIMENSION(:,:,:) :: A
INTEGER(8) :: M, N, K, LDA, LD2A, LWORK
REAL(8), DIMENSION(:) :: WORK
C INTERFACE
#include <sunperf.h>
void zfft3b(int m, int n, int k, doublecomplex *a, int lda,
int ld2a, double *work, int lwork);
void zfft3b_64(long m, long n, long k, doublecomplex *a,
long lda, long ld2a, double *work, long lwork);
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.
K (input) Number of planes to be transformed. These subrou-
tines 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 initial-
ized by ZFFT3I.
LWORK (input)
The dimension of the array WORK. LWORK >= (4*(M +
N + K) + 45).