ba237a9d91
Files correlati : Ricompilazione Demo : [ ] Commento : Aggiunti i sorgenti per Greenleaf Math Library (gfm.dll) git-svn-id: svn://10.65.10.50/trunk@10079 c028cbd2-c16b-5b4b-a496-9718f37d4682
57 lines
1.0 KiB
C
Executable File
57 lines
1.0 KiB
C
Executable File
/* void _CosDecSmall(pDst,pSrc)
|
|
*
|
|
* ARGUMENT
|
|
* DEC *pDst, *pSrc;
|
|
*
|
|
* DESCRIPTION
|
|
* Sets pDst = cos(pSrc), where 0 <= pSrc < pi / 4.
|
|
*
|
|
* SIDE EFFECTS
|
|
* None.
|
|
*
|
|
* RETURNS
|
|
* None.
|
|
*
|
|
* ALGORITHM
|
|
* Using the Taylor series,
|
|
* cos(x) = 1 - x^2/2! + x^4/4! - ...
|
|
*
|
|
* AUTHOR
|
|
* Jared Levy April 7, 1987
|
|
* Copyright (C) 1987-1990 Greenleaf Software Inc. All rights reserved.
|
|
*
|
|
* MODIFICATIONS
|
|
*
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include "gm.h"
|
|
#include "gmsystem.h"
|
|
|
|
void _CosDecSmall(pDst,pSrc)
|
|
DEC *pDst, *pSrc;
|
|
{
|
|
DEC *srcsq, dsrcsq, *term, dterm, *fact, dfact;
|
|
SHORT i;
|
|
|
|
srcsq = &dsrcsq;
|
|
(void) _MulDec80Bit(srcsq, pSrc, pSrc);
|
|
(void) ConvLongToDecimal(pDst, 1L);
|
|
term = &dterm;
|
|
(void) _MulDec80Bit(term, srcsq, &decPoint5);
|
|
i = 2;
|
|
fact = ConvLongToDecimal(&dfact, 6L);
|
|
while (!(_MacIsDecZ(term))) {
|
|
if ((i % 4) == 0)
|
|
(void) _AddDec80Bit(pDst, pDst, term);
|
|
else
|
|
(void) _SubDec80Bit(pDst, pDst, term);
|
|
i+=2;
|
|
_MulDec80Bit(term, term, srcsq);
|
|
fact->dc.sl[0] = i * (i - 1);
|
|
_DivRndDec80Bit(term, term, fact, 23);
|
|
}
|
|
|
|
}
|
|
|