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NAME
     sint - compute the discrete Fourier sine transform of an odd
     sequence.  The xSINT transforms are unnormalized inverses of
     themselves, so a call of xSINT followed by another  call  of
     xSINT  will  multiply  the input sequence by 2 * (N+1).  The
     VxSINT transforms are normalized, so a call of  VxSINT  fol-
     lowed by a call of VxSINT will return the original sequence.

SYNOPSIS
     SUBROUTINE SINT (N, RX, RWSAVE)

     SUBROUTINE DSINT (N, DX, DWSAVE)

     SUBROUTINE VSINT (M, N, RX, RXT, MDIMX, RWSAVE)

     SUBROUTINE VDSINT (M, N, DX, DXT, MDIMX, DWSAVE)



     #include <sunperf.h>

     void sint (int n, float *sx, float *wsave) ;

     void dsint (int n, double *dx, double *wsave) ;

     void vsint(int m, int n, float *sx, int mdimx, float *wsave)
               ;

     void vdsint(int m, int n,  double  *dx,  int  mdimx,  double
               *wsave) ;

ARGUMENTS
     M         (For vector operations only.)
               The number of sequences to be transformed.   M  >=
               0.

     N         Length of the sequence to be  transformed.   These
               subroutines  are most efficient when N+1 is a pro-
               duct of small primes.  N >= 0.

     xX        On entry, an array  of  length  N  containing  the
               sequence  to  be  transformed.  For VxSINT, a real
               two-dimensional array with dimensions of (MDIMX  x
               (N+1))  whose  rows  contain  the  sequences to be
               transformed.  On exit, the sine transform  of  the
               input.

     xXT       (For vector operations only.)
               A real two-dimensional work array with  dimensions
               of (MDIMX x (N+1)).

     MDIMX     (For vector operations only.)
               Leading dimension of the  arrays  xX  and  xXT  as
               specified in a dimension or type statement.  MDIMX
               >= M.

     xWSAVE    On entry, an array  with  dimension  of  at  least
               int(2.5  *  N  +  15)  initialized  by  xSINTI  or
               VxSINTI.

SAMPLE PROGRAM
           PROGRAM TEST
           IMPLICIT NONE
     C
           INTEGER             N
           PARAMETER          (N = 9)
     C
           INTEGER             I
           REAL                PI, WSAVE(3 * N + 15), X(N)
     C
           EXTERNAL            SINT, SINTI
           INTRINSIC           ACOS, SIN
     C
     C     Initialize the array X to an odd sequence, that is, it can be
     C     expanded in terms of a trigonometric series that contains only
     C     sine terms.
     C
           PI = ACOS (-1.0)
           DO 100, I=1, N
             X(I) =  SIN ( I * 2.0 * PI / (N + 1.0))
       100 CONTINUE
     C
           PRINT 1000
           PRINT 1010, (X(I), I = 1, N)
           CALL SINTI (N, WSAVE)
           CALL SINT (N, X, WSAVE)
           PRINT 1020
           PRINT 1010, (X(I), I = 1, N)
           CALL SINT (N, X, WSAVE)
           PRINT 1030
           PRINT 1010, (X(I), I = 1, N)
     C
      1000 FORMAT (1X, 'Original Sequence: ')
      1010 FORMAT (1X, 100(F7.3, 1X))
      1020 FORMAT (1X, 'Transformed Sequence: ')
      1030 FORMAT (1X, 'Recovered Sequence: ')
     C
           END

SAMPLE OUTPUT
      Original Sequence:
        0.588   0.951   0.951   0.588   0.000  -0.588  -0.951   -
     0.951  -0.588
      Transformed Sequence:
        0.000  10.000   0.000    0.000    0.000    0.000    0.000
     0.000   0.000
      Recovered Sequence:
       11.756  19.021  19.021   11.756    0.000  -11.756  -19.021
     -19.021 -11.756

Партнёры:

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