campo-sirio/gfm/drooti.c
alex ba237a9d91 Patch level : no patch
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
2002-02-26 12:19:02 +00:00

104 lines
1.6 KiB
C
Executable File

/* DEC *RootInteger(pDst,pSrc1,n)
*
* ARGUMENT
* DEC *pDst,*pSrc1;
* int n;
*
* DESCRIPTION
* Calculates the n'th root of pSrc1 and returns the answer in pDst.
* This provides an x**(1/n) power function for DEC numbers.
*
* SIDE EFFECTS
* None.
*
* RETURNS
* Pointer to the result if no error, otherwise GM_NULL.
*
* ALGORITHM:
* x**(1/n) = e**(ln(x)/n).
*
* POSSIBLE ERROR CODES
*
* GM_NULLPOINTER
* GM_OVERFLOW
* GM_UNDERFLOW
* GM_IMAG
* GM_PWR0
* GM_DIV0
*
* AUTHOR
* Andy Anderson 05-JAN-1987 17:30
* Copyright (C) 1987-1990 Greenleaf Software Inc. All rights reserved.
*
* MODIFICATIONS
*
*/
#include <stdio.h>
#include "gm.h"
#include "gmsystem.h"
DEC *RootInteger(pDst,pSrc,n)
DEC *pDst, *pSrc;
int n;
{
DEC temp, *pt, *nsrc, dnsrc, ddn, *dn=&ddn;
int i, isn=0;
_MacStart(GM_DROOTI);
_MacInVarD(pSrc);
_MacOutVarD(pDst);
if (_MacIsDecZ(pSrc)) {
if (n>0) {
_MacDZero(pDst);
_MacRet(pDst);
}
else {
_MacErr(GM_PWR0);
_MacRet(GM_NULL);
}
}
if (_MacIsDecN(pSrc)) {
if ((n % 2) == 0) {
_MacErr(GM_IMAG);
_MacRet(GM_NULL);
}
isn=1;
nsrc = &dnsrc;
_MacDCopy(nsrc,pSrc);
pSrc=nsrc;
_MacDChgs(nsrc);
}
pt = &temp;
(void) _LnDec80Bit(pt, pSrc);
(void) ConvLongToDecimal(dn, (long) n);
(void) _DivDec80Bit(pt, pt, dn);
i = _ExpDec80Bit(pt, pt);
if(i==GM_OVERFLOW) {
_MacErr(i);
_MacRet(GM_NULL);
}
i = _Sq5UnsTo4Uns(pt);
if(i!=GM_SUCCESS) {
_MacErr(GM_OVERFLOW);
_MacRet(GM_NULL);
}
if (_MacIsDecZ(pt)) {
_MacErr(GM_UNDERFLOW);
}
if (isn)
_MacDChgs(pt);
_MacDCopy(pDst,pt);
_MacRet(pDst);
}