campo-sirio/gfm/dmean.c

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/* DEC *StatMean(pDst,pSrc,n)
*
* ARGUMENT
* DEC *pDst;
* DEC **pSrc;
* int n;
*
* DESCRIPTION
* Sets pDst to the mean of the n DEC elements of the array pSrc.
* n <= 0 is not allowed. pDst is unchanged if an error occurs.
*
* SIDE EFFECTS
* None.
*
* RETURNS
* Returns pointer to the average if successful, otherwise
* returns GM_NULL.
*
* POSSIBLE ERROR CODES
*
* GM_NULLPOINTER
* GM_ARGVAL
* GM_UNDERFLOW
*
* AUTHOR
* Jared Levy
* Copyright (C) 1987-1990 Greenleaf Software Inc. All rights reserved.
*
* MODIFICATIONS
*
*/
#include <stdio.h>
#include "gm.h"
#include "gmsystem.h"
DEC *StatMean(pDst,pSrc,n)
DEC *pDst;
DEC **pSrc;
int n;
{
int i;
DEC *p, dsum, *sum=&dsum, ddn, *dn=&ddn;
/* source must be supplied !! */
_MacStart(GM_DMEAN);
if (!pSrc) {
_MacErr(GM_NULLPOINTER);
_MacRet(GM_NULL);
}
if (n<=0) {
_MacErr(GM_ARGVAL);
_MacRet(GM_NULL);
}
for (i=0; i<n; i++)
_MacInVarD(pSrc[i]);
_MacOutVarD(pDst);
p = pSrc[0];
_MacDCopy(sum, p);
for (i=1;i<n;i++) {
p = pSrc[i];
(void) _AddDec80Bit(sum, sum, p);
/* overflow impossible here since sum is 80 bits */
}
(void) ConvLongToDecimal(dn, (long) n);
pDst = DivideDecimal(pDst, sum, dn);
_MacRet(pDst);
}