modf

modf

Floating-Point Conversion: Fraction-Integer Split

Portability: ISO/ANSI C conforming, UNIX compatible

SYNOPSIS
DESCRIPTION
RETURN VALUE
IMPLEMENTATION
EXAMPLE
RELATED FUNCTIONS
SEE ALSO

SYNOPSIS

#include <math.h>

double modf(double y, double *p);

DESCRIPTION

modf separates an argument of type double into fractional and integer parts.

RETURN VALUE

modf returns the fractional part of the argument y with the same sign as y . The integer part of y , expressed as a floating-point number, is stored in the location referenced by the pointer p .

IMPLEMENTATION

modf is implemented as a built-in function unless it is undefined by an #undef statement.

EXAMPLE

#include <math.h>
#include <stdio.h>

main()
{
   double weight;
   double intweight;
   float limit = 0.5;

   puts("Enter a weight");
   scanf("%lf",&weight);
      /* Check to see if weight is negative.                    */
   if (weight < 0) {
      puts("Weight can not be a negative number");
      exit(1);
   }

      /* Test whether fractional part equals or exceeds limit.  */
   if (modf(weight, &intweight) >= limit)
       weight = intweight + 1; /* If yes, add 1 to weight.      */
   else
       weight = intweight;     /* Otherwise, round down weight. */
   printf("Your weight rounded off to the nearest pound is %f\n",
          weight);
}

RELATED FUNCTIONS

ceil , floor , fmod

SEE ALSO

Mathematical Functions

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