zfftz2 - pute the two-dimensional Fast Fourier Transform (forward or inverse) of a two-dimensional double complex array.
SUBROUTINE ZFFTZ2(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER IOPT, M, N, LDX, LDY, IFAC(*), LWORK, IERR DOUBLE COMPLEX X(LDX, *), Y(LDY, *) DOUBLE PRECISION SCALE, TRIGS(*), WORK(*) SUBROUTINE ZFFTZ2_64(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER*8 IOPT, M, N, LDX, LDY, IFAC(*), LWORK, IERR DOUBLE PRECISION SCALE, TRIGS(*), WORK(*) DOUBLE COMPLEX X(LDX, *), Y(LDY, *) F95 INTERFACE SUBROUTINE FFT2(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER, INTENT(IN) :: IOPT INTEGER, INTENT(IN), OPTIONAL :: M, N, LDX, LDY, LWORK REAL(8), INTENT(IN), OPTIONAL :: SCALE COMPLEX(8), INTENT(IN), DIMENSION(:,:) :: X COMPLEX(8), INTENT(OUT), DIMENSION(:,:) :: Y REAL(8), INTENT(INOUT), DIMENSION(:) :: TRIGS INTEGER, INTENT(INOUT), DIMENSION(:) :: IFAC REAL(8), INTENT(OUT), DIMENSION(:) :: WORK INTEGER, INTENT(OUT) :: IERR SUBROUTINE FFT2_64(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER(8), INTENT(IN) :: IOPT INTEGER(8), INTENT(IN), OPTIONAL :: M, N, LDX, LDY, LWORK REAL(8), INTENT(IN), OPTIONAL :: SCALE COMPLEX(8), INTENT(IN), DIMENSION(:,:) :: X COMPLEX(8), INTENT(OUT), DIMENSION(:,:) :: Y REAL(8), INTENT(INOUT), DIMENSION(:) :: TRIGS INTEGER(8), INTENT(INOUT), DIMENSION(:) :: IFAC REAL(8), INTENT(OUT), DIMENSION(:) :: WORK INTEGER(8), INTENT(OUT) :: IERR C INTERFACE #include <sunperf.h> void zfftz2_ (int *iopt, int *n1, int *n2, double *scale, doublecomplex *x, int *ldx, doublecomplex *y, int *ldy, double *trigs, int *ifac, double *work, int *lwork, int *ierr); void zfftz2_64_ (long *iopt, long *n1, long *n2, double *scale, double- complex *x, long *ldx, doublecomplex *y, long *ldy, double *trigs, long *ifac, double *work, long *lwork, long *ierr);
Oracle Solaris Studio Performance Library zfftz2(3P) NAME zfftz2 - initialize the trigonometric weight and factor tables or com- pute the two-dimensional Fast Fourier Transform (forward or inverse) of a two-dimensional double complex array. SYNOPSIS SUBROUTINE ZFFTZ2(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER IOPT, M, N, LDX, LDY, IFAC(*), LWORK, IERR DOUBLE COMPLEX X(LDX, *), Y(LDY, *) DOUBLE PRECISION SCALE, TRIGS(*), WORK(*) SUBROUTINE ZFFTZ2_64(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER*8 IOPT, M, N, LDX, LDY, IFAC(*), LWORK, IERR DOUBLE PRECISION SCALE, TRIGS(*), WORK(*) DOUBLE COMPLEX X(LDX, *), Y(LDY, *) F95 INTERFACE SUBROUTINE FFT2(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER, INTENT(IN) :: IOPT INTEGER, INTENT(IN), OPTIONAL :: M, N, LDX, LDY, LWORK REAL(8), INTENT(IN), OPTIONAL :: SCALE COMPLEX(8), INTENT(IN), DIMENSION(:,:) :: X COMPLEX(8), INTENT(OUT), DIMENSION(:,:) :: Y REAL(8), INTENT(INOUT), DIMENSION(:) :: TRIGS INTEGER, INTENT(INOUT), DIMENSION(:) :: IFAC REAL(8), INTENT(OUT), DIMENSION(:) :: WORK INTEGER, INTENT(OUT) :: IERR SUBROUTINE FFT2_64(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER(8), INTENT(IN) :: IOPT INTEGER(8), INTENT(IN), OPTIONAL :: M, N, LDX, LDY, LWORK REAL(8), INTENT(IN), OPTIONAL :: SCALE COMPLEX(8), INTENT(IN), DIMENSION(:,:) :: X COMPLEX(8), INTENT(OUT), DIMENSION(:,:) :: Y REAL(8), INTENT(INOUT), DIMENSION(:) :: TRIGS INTEGER(8), INTENT(INOUT), DIMENSION(:) :: IFAC REAL(8), INTENT(OUT), DIMENSION(:) :: WORK INTEGER(8), INTENT(OUT) :: IERR C INTERFACE #include <sunperf.h> void zfftz2_ (int *iopt, int *n1, int *n2, double *scale, doublecomplex *x, int *ldx, doublecomplex *y, int *ldy, double *trigs, int *ifac, double *work, int *lwork, int *ierr); void zfftz2_64_ (long *iopt, long *n1, long *n2, double *scale, double- complex *x, long *ldx, doublecomplex *y, long *ldy, double *trigs, long *ifac, double *work, long *lwork, long *ierr); PURPOSE zfftz2 initializes the trigonometric weight and factor tables or com- putes the two-dimensional Fast Fourier Transform (forward or inverse) of a two-dimensional double complex array. In computing the two-dimen- sional FFT, one-dimensional FFTs are computed along the columns of the input array. One-dimensional FFTs are then computed along the rows of the intermediate results. N-1 M-1 Y(k1,k2) = scale * SUM SUM W2*W1*X(j1,j2) j2=0 j1=0 where k1 ranges from 0 to M-1 and k2 ranges from 0 to N-1 i = sqrt(-1) isign = 1 for inverse transform or -1 for forward transform W1 = exp(isign*i*j1*k1*2*pi/M) W2 = exp(isign*i*j2*k2*2*pi/N) ARGUMENTS IOPT (input) Integer specifying the operation to be performed: IOPT = 0 computes the trigonometric weight table and factor table IOPT = -1 computes forward FFT IOPT = +1 computes inverse FFT M (input) Integer specifying length of the transform in the first dimension. M is most efficient when it is a product of small primes. M >= 0. Unchanged on exit. N (input) Integer specifying length of the transform in the second dimension. N is most efficient when it is a product of small primes. N >= 0. Unchanged on exit. SCALE (input) Double precision scalar by which transform results are scaled. Unchanged on exit. X (input) X is a double complex array of dimensions (LDX, N) that con- tains input data to be transformed. LDX (input) Leading dimension of X. LDX >= M Unchanged on exit. Y (output) Y is a double complex array of dimensions (LDY, N) that con- tains the transform results. X and Y can be the same array starting at the same memory location, in which case the input data are overwritten by their transform results. Otherwise, it is assumed that there is no overlap between X and Y in memory. LDY (input) Leading dimension of Y. If X and Y are the same array, LDY = LDX Else LDY >= M Unchanged on exit. TRIGS (input/output) Double precision array of length 2*(M+N) that contains the trigonometric weights. The weights are computed when the routine is called with IOPT = 0 and they are used in subse- quent calls when IOPT = 1 or IOPT = -1. Unchanged on exit. IFAC (input/output) Integer array of dimension at least 2*128 that contains the factors of M and N. The factors are computed when the rou- tine is called with IOPT = 0 and they are used in subsequent calls when IOPT = 1 or IOPT = -1. Unchanged on exit. WORK (workspace) Double precision array of dimension at least 2*MAX(M,N)*NCPUS where NCPUS is the number of threads used to execute the rou- tine. The user can also choose to have the routine allocate its own workspace (see LWORK). LWORK (input) Integer specifying workspace size. If LWORK = 0, the routine will allocate its own workspace. IERR (output) On exit, integer IERR has one of the following values: 0 = normal return -1 = IOPT is not 0, 1 or -1 -2 = M < 0 -3 = N < 0 -4 = (LDX < M) -5 = (LDY < M) or (LDY not equal LDX when X and Y are same array) -6 = (LWORK not equal 0) and (LWORK < 2*MAX(M,N)*NCPUS) -7 = memory allocation failed SEE ALSO fft CAUTIONS On exit, entire output array Y(1:LDY, 1:N) is overwritten. 7 Nov 2015 zfftz2(3P)