dfftzm - pute the one-dimensional forward Fast Fourier Transform of a set of double precision data sequences stored in a two-dimensional array.
SUBROUTINE DFFTZM(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR) INTEGER IOPT, M, N, LDX, LDY, IFAC(*), LWORK, IERR DOUBLE PRECISION X(LDX, *), SCALE, TRIGS(*), WORK(*) DOUBLE COMPLEX Y(LDY, *) SUBROUTINE DFFTZM_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 X(LDX, *), SCALE, TRIGS(*), WORK(*) DOUBLE COMPLEX Y(LDY, *) F95 INTERFACE SUBROUTINE FFTM(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 REAL(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 FFTM_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 REAL(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 dfftzm_ (int *iopt, int *m, int *n, double *scale, double *x, int *ldx, doublecomplex *y, int *ldy, double *trigs, int *ifac, double *work, int *lwork, int *ierr); void dfftzm_64_ (long *iopt, long *m, long *n, double *scale, double *x, long *ldx, doublecomplex *y, long *ldy, double *trigs, long *ifac, double *work, long *lwork, long *ierr);
Oracle Solaris Studio Performance Library dfftzm(3P)
NAME
dfftzm - initialize the trigonometric weight and factor tables or com-
pute the one-dimensional forward Fast Fourier Transform of a set of
double precision data sequences stored in a two-dimensional array.
SYNOPSIS
SUBROUTINE DFFTZM(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR)
INTEGER IOPT, M, N, LDX, LDY, IFAC(*), LWORK, IERR
DOUBLE PRECISION X(LDX, *), SCALE, TRIGS(*), WORK(*)
DOUBLE COMPLEX Y(LDY, *)
SUBROUTINE DFFTZM_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 X(LDX, *), SCALE, TRIGS(*), WORK(*)
DOUBLE COMPLEX Y(LDY, *)
F95 INTERFACE
SUBROUTINE FFTM(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
REAL(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 FFTM_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
REAL(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 dfftzm_ (int *iopt, int *m, int *n, double *scale, double *x, int
*ldx, doublecomplex *y, int *ldy, double *trigs, int *ifac,
double *work, int *lwork, int *ierr);
void dfftzm_64_ (long *iopt, long *m, long *n, double *scale, double
*x, long *ldx, doublecomplex *y, long *ldy, double *trigs,
long *ifac, double *work, long *lwork, long *ierr);
PURPOSE
dfftzm initializes the trigonometric weight and factor tables or com-
putes the one-dimensional forward Fast Fourier Transform of a set of
double precision data sequences stored in a two-dimensional array:
M-1
Y(k,l) = scale * SUM W*X(j,l)
j=0
where
k ranges from 0 to M-1 and l ranges from 0 to N-1
i = sqrt(-1)
isign = -1 for forward transform
W = exp(isign*i*j*k*2*pi/M)
In real-to-complex transform of length M, the (M/2+1) complex output
data points stored are the positive-frequency half of the spectrum of
the discrete Fourier transform. The other half can be obtained through
complex conjugation and therefore is not stored.
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
M (input)
Integer specifying length of the input sequences. M is most
efficient when it is a product of small primes. M >= 0.
Unchanged on exit.
N (input)
Integer specifying number of input sequences. 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 precision array of dimensions (LDX, N) that
contains the sequences to be transformed stored in its col-
umns.
LDX (input)
Leading dimension of X. If X and Y are the same array, LDX =
2*LDY Else LDX >= M Unchanged on exit.
Y (output)
Y is a double complex array of dimensions (LDY, N) that con-
tains the transform results of the input sequences. X and Y
can be the same array starting at the same memory location,
in which case the input sequences 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. LDY >= M/2 + 1 Unchanged on exit.
TRIGS (input/output)
Double precision array of length 2*M 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. Unchanged on exit.
IFAC (input/output)
Integer array of dimension at least 128 that contains the
factors of M. The factors are computed when the routine is
called with IOPT = 0 and they are used in subsequent calls
when IOPT = -1. Unchanged on exit.
WORK (workspace)
Double precision array of dimension at least M. 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 or -1
-2 = M < 0
-3 = N < 0
-4 = (LDX < M) or (LDX not equal 2*LDY when X and Y are same
array)
-4 = (LDY < M/2 + 1)
-6 = (LWORK not equal 0) and (LWORK < M)
-7 = memory allocation failed
SEE ALSO
fft
7 Nov 2015 dfftzm(3P)