sfftcm (3p)

Name

sfftcm - pute the one-dimensional forward Fast Fourier Transform of a set of real data sequences stored in a two-dimensional array.

Synopsis

SUBROUTINE SFFTCM(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR)

INTEGER IOPT, M, N, LDX, LDY, IFAC(*), LWORK, IERR
REAL X(LDX, *), SCALE, TRIGS(*), WORK(*)
COMPLEX Y(LDY, *)

SUBROUTINE SFFTCM_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 X(LDX, *), SCALE, TRIGS(*), WORK(*)
COMPLEX Y(LDY, *)




F95 INTERFACE
SUBROUTINE FFTM(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
REAL, 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 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, INTENT(IN), OPTIONAL :: SCALE
REAL, 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  sfftcm_ (int *iopt, int *n1, int *n2, float *scale, float *x, int
*ldx, complex *y, int *ldy, float *trigs,  int  *ifac,  float
*work, int *lwork, int *ierr);

void  sfftcm_64_  (long  *iopt, long *n1, long *n2, float *scale, float
*x, long *ldx, complex *y,  long  *ldy,  float  *trigs,  long
*ifac, float *work, long *lwork, long *ierr);

Description

Oracle Solaris Studio Performance Library                           sfftcm(3P)



NAME
       sfftcm  - initialize the trigonometric weight and factor tables or com-
       pute the one-dimensional forward Fast Fourier Transform  of  a  set  of
       real data sequences stored in a two-dimensional array.

SYNOPSIS
       SUBROUTINE SFFTCM(IOPT, M, N, SCALE, X, LDX, Y, LDY, TRIGS, IFAC, WORK, LWORK, IERR)

       INTEGER IOPT, M, N, LDX, LDY, IFAC(*), LWORK, IERR
       REAL X(LDX, *), SCALE, TRIGS(*), WORK(*)
       COMPLEX Y(LDY, *)

       SUBROUTINE SFFTCM_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 X(LDX, *), SCALE, TRIGS(*), WORK(*)
       COMPLEX Y(LDY, *)




   F95 INTERFACE
       SUBROUTINE FFTM(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
       REAL, 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 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, INTENT(IN), OPTIONAL :: SCALE
       REAL, 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  sfftcm_ (int *iopt, int *n1, int *n2, float *scale, float *x, int
                 *ldx, complex *y, int *ldy, float *trigs,  int  *ifac,  float
                 *work, int *lwork, int *ierr);

       void  sfftcm_64_  (long  *iopt, long *n1, long *n2, float *scale, float
                 *x, long *ldx, complex *y,  long  *ldy,  float  *trigs,  long
                 *ifac, float *work, long *lwork, long *ierr);



PURPOSE
       sfftcm  initializes  the trigonometric weight and factor tables or com-
       putes the one-dimensional forward Fast Fourier Transform of  a  set  of
       real 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)
                 Real scalar by which transform results are scaled.  Unchanged
                 on exit.

       X (input) X  is  a  real array of dimensions (LDX, N) that contains the
                 sequences to be transformed stored in its columns.

       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 complex array of dimensions (LDY, N) that contains 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)
                 Real 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 subsequent 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)
                 Real 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                        sfftcm(3P)