{{keywords>wiki library source code example reference}}
===== frexp =====
<code c>
    double frexp(double);
</code>
Mantissa m. in *n is the exponent.

===== C Sourcecode Example =====
compile in linux with: gcc frexp.c -o frexp **-lm** -Wall
<code c>     
#include <stdio.h> /* including standard library */
//#include <windows.h> /* uncomment this for Windows */

#include <math.h> /* including math library */

int main ( void ) 
{
  double x;
  int n;

  x = 42.0;
  printf ("%lf * 2^%d = %f\n", frexp (x , &n), n, x);
  return 0;
}



</code>
==== output ====
   output:
   user@host:~$ ./frexp 
   0.656250 * 2^0 = 42.000000