frexp

Syntax

#include <math.h> double frexp(double x, int *pexp);

Description

This function separates the given value x into a mantissa m in the range [0.5,1) and an exponent e, such that m*2^e = x. It returns the value of the mantissa and stores the integer exponent in *pexp.

Return Value

The mantissa. If the value of x is NaN or Inf, the return value is NaN, zero is stored in *pexp, and errno is set to EDOM. If x is zero, *pexp and the return value are also both zero.

Portability

ANSI/ISO C	C89; C99
POSIX	1003.2-1992; 1003.1-2001