www.pudn.com > CRGAB.zip > RNDNICK.C

/* 
HEADER:         ; 
TITLE:          round to nearest nickel; 
VERSION:        1.0; 
 
DESCRIPTION:    function rounds value to nearest nickel 
 
KEYWORDS:       rouding, nickel; 
SYSTEM:         Xenix 3.4b, MSDOS; 
FILENAME:       rndnick.c 
WARNINGS:       compile with -dNO_PROTOTYPE if your system does not 
                support prototyping, with -dFOR_MSDOS if you are compiling 
                for MSDOS with an ANSI standard compiler. 
                Defaults assume compiling with prototypes for 
                Xenix 3.4b on Altos 2086 computer. 
 
SEE-ALSO:       vernmath.h 
AUTHORS:        Vern Martin, 449 W. Harrison, Alliance, Ohio 44601; 
COMPILERS:      ECOSOFT ECO-C88, XENIX 3.4B STANDARD COMPILER; 
*/ 
 
#include "vernmath.h" 
 
#define ROUND_TO_NEAREST    (5.0)   /* round to neareast 5 cents */ 
#define CUT_OFF             (3)     /* less than this and round down, 
                                        greater or ==, and round up */ 
 
double rndnick(amt) 
double amt; /* amount to round */ 
{ 
    double remainder;   /* remainder after modulus operation */ 
 
    /* multiply amount by 100 and then throw away anything 
        that is right of the decimal */ 
    /* then perform modulus arithmetic to find out what remainder 
        is afger deviding by the ROUND_TO_NEAREST factor (nickel) */ 
 
 
    amt = nrnd54(amt,2) * 100; 
 
    /* round output of fmod(), it is not an exact number and must be ! */ 
    remainder = nrnd54(fmod(amt,ROUND_TO_NEAREST),0); 
 
    /* now, if remainder is less than the cut off, subtract it from 
        the amount, else add the difference between the remainder 
        and the cut off, thus rounding up to the nearest nickel */ 
 
    if ( (int) remainder < CUT_OFF )  { 
        amt -= remainder; 
    } 
    else { 
        amt += ROUND_TO_NEAREST - remainder; 
    } 
 
    return( amt * .01 ); 
 
}