multiply by integer power of 2

You're viewing an older version of this page (#3435). View the current version.

View versions (4)

INTERFACE

#include <math.h>

double ldexp ( double x, int n ) long ldexpl ( long double x, int n ) float ldexpf ( float x, int n )

DESCRIPTION

The ldexp functions multiply x by 2 to the power of n.

Example 1

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

int main(void)
{
  double x = 3.14, result = ldexp(x, 10);
  printf("%.2lf * 2^10 = %.2lf\n", x, result);
  return 0;
}

Output:

3.14 * 2^10 = 3215.36

SPECIAL VALUES

ldexp (&plusmn;0, n) returns &plusmn;0.
ldexp (x, 0) returns x.
ldexp (&plusmn;&infin;, n) returns &plusmn;&infin;.

SEE ALSO

pow

STANDARDS

The ldexp functions conform to ISO/IEC 9899:1999(E).