cfftc2 - pute the two-dimensional Fast Fourier Transform (forward or inverse) of a two-dimensional complex array.
SUBROUTINE CFFTC2(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER IOPT, M, N, LDX, LDY, IFAC(*), LWORK, IERR COMPLEX X(LDX, *), Y(LDY, *) REAL SCALE, TRIGS(*), WORK(*) SUBROUTINE CFFTC2_64(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER*8 IOPT, M, N, LDX, LDY, IFAC(*), LWORK, IERR REAL SCALE, TRIGS(*), WORK(*) COMPLEX X(LDX, *), Y(LDY, *) F95 INTERFACE SUBROUTINE FFT2(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER*4, INTENT(IN) :: IOPT INTEGER*4, INTENT(IN), OPTIONAL :: M, N, LDX, LDY, LWORK REAL, INTENT(IN), OPTIONAL :: SCALE COMPLEX, INTENT(IN), DIMENSION(:,:) :: X COMPLEX, INTENT(OUT), DIMENSION(:,:) :: Y REAL, INTENT(INOUT), DIMENSION(:) :: TRIGS INTEGER*4, INTENT(INOUT), DIMENSION(:) :: IFAC REAL, INTENT(OUT), DIMENSION(:) :: WORK INTEGER*4, 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, INTENT(IN), OPTIONAL :: SCALE COMPLEX, INTENT(IN), DIMENSION(:,:) :: X COMPLEX, INTENT(OUT), DIMENSION(:,:) :: Y REAL, INTENT(INOUT), DIMENSION(:) :: TRIGS INTEGER(8), INTENT(INOUT), DIMENSION(:) :: IFAC REAL, INTENT(OUT), DIMENSION(:) :: WORK INTEGER(8), INTENT(OUT) :: IERR C INTERFACE #include <sunperf.h> void cfftc2_ (int *iopt, int *n1, int *n2, float *scale, complex *x, int *ldx, complex *y, int *ldy, float *trigs, int *ifac, float *work, int *lwork, int *ierr); void cfftc2_64_ (long *iopt, long *n1, long *n2, float *scale, complex *x, long *ldx, complex *y, long *ldy, float *trigs, long *ifac, float *work, long *lwork, long *ierr);
Oracle Solaris Studio Performance Library cfftc2(3P) NAME cfftc2 - initialize the trigonometric weight and factor tables or com- pute the two-dimensional Fast Fourier Transform (forward or inverse) of a two-dimensional complex array. SYNOPSIS SUBROUTINE CFFTC2(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER IOPT, M, N, LDX, LDY, IFAC(*), LWORK, IERR COMPLEX X(LDX, *), Y(LDY, *) REAL SCALE, TRIGS(*), WORK(*) SUBROUTINE CFFTC2_64(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER*8 IOPT, M, N, LDX, LDY, IFAC(*), LWORK, IERR REAL SCALE, TRIGS(*), WORK(*) COMPLEX X(LDX, *), Y(LDY, *) F95 INTERFACE SUBROUTINE FFT2(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER*4, INTENT(IN) :: IOPT INTEGER*4, INTENT(IN), OPTIONAL :: M, N, LDX, LDY, LWORK REAL, INTENT(IN), OPTIONAL :: SCALE COMPLEX, INTENT(IN), DIMENSION(:,:) :: X COMPLEX, INTENT(OUT), DIMENSION(:,:) :: Y REAL, INTENT(INOUT), DIMENSION(:) :: TRIGS INTEGER*4, INTENT(INOUT), DIMENSION(:) :: IFAC REAL, INTENT(OUT), DIMENSION(:) :: WORK INTEGER*4, 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, INTENT(IN), OPTIONAL :: SCALE COMPLEX, INTENT(IN), DIMENSION(:,:) :: X COMPLEX, INTENT(OUT), DIMENSION(:,:) :: Y REAL, INTENT(INOUT), DIMENSION(:) :: TRIGS INTEGER(8), INTENT(INOUT), DIMENSION(:) :: IFAC REAL, INTENT(OUT), DIMENSION(:) :: WORK INTEGER(8), INTENT(OUT) :: IERR C INTERFACE #include <sunperf.h> void cfftc2_ (int *iopt, int *n1, int *n2, float *scale, complex *x, int *ldx, complex *y, int *ldy, float *trigs, int *ifac, float *work, int *lwork, int *ierr); void cfftc2_64_ (long *iopt, long *n1, long *n2, float *scale, complex *x, long *ldx, complex *y, long *ldy, float *trigs, long *ifac, float *work, long *lwork, long *ierr); PURPOSE cfftc2 initializes the trigonometric weight and factor tables or com- putes the two-dimensional Fast Fourier Transform (forward or inverse) of a two-dimensional complex array. In computing the two-dimensional 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) Real scalar by which transform results are scaled. Unchanged on exit. X (input) X is a complex array of dimensions (LDX, N) that contains input data to be transformed. LDX (input) Leading dimension of X. LDX >= M Unchanged on exit. Y (output) Y is a complex array of dimensions (LDY, N) that contains 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) Real 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 subsequent 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) Real array of dimension at least 2*MAX(M,N)*NCPUS where NCPUS is the number of threads used to execute the routine. 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 cfftc2(3P)