#include <math.h>

        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 . The

      example produces the following output:

        fraction = 0.500000
        exp = 5

      |value| = Infinity or NaN is an invalid argument.