sinti(3P)

NAME

sinti - initialize the array xWSAVE, which is used in subroutine xSINT.

SYNOPSIS

SUBROUTINE SINTI (N, RWSAVE)

SUBROUTINE DSINTI (N, DWSAVE)

SUBROUTINE VSINTI (N, WSAVE)

SUBROUTINE VDSINTI (N, WSAVE)

#include <sunperf.h>

void sinti (int n, float ∗rwsave) ;

void dsinti (int n, double ∗dwsave) ;

void vsinti (int n, float ∗rwsave) ;

void vdsinti (int n, float ∗dwsave) ;

ARGUMENTS

N Length of the sequence to be transformed. N >= 0.

xWSAVE On entry, an array with a dimension of at least (3 ∗ N + 15). Different xWSAVE arrays are required for different values of N. This initialization does not have to be repeated between calls to xSINT as long as N and xWSAVE remain unchanged, thus subsequent transforms can be obtained faster than the first.

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