frexp

Calculates the fractional and exponent parts of a double value.

Format 

#include  <math.h>

double frexp  (double value, int *eptr);

Arguments

value
An object of type double.
eptr
A pointer to an int, to which frexp returns the exponent.

Description

This function converts value to the following form: 
value = fraction * (2exp)

The fractional part is returned as the return value. The exponent is placed in the integer variable pointed to by eptr.

Example

    main ()
{
   double val = 16.0, fraction;
   int exp;

   fraction = frexp(val, &exp);
   printf("fraction = %f\n",fraction);
   printf("exp = %d\n",exp);

}

    In this example, frexp converts the value 16 to .5*2 5 . The example produces the following output: 

    fraction = 0.500000
exp = 5

Return Value
x  The fractional part of the double value. 

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