FREXP(3P) POSIX Programmer s Manual FREXP(3P)


NAME frexp, frexpf, frexpl - extract mantissa and exponent from a double precision number

SYNOPSIS #include <math.h>

double frexp(double num, int *exp); float frexpf(float num, int *exp); long double frexpl(long double num, int *exp);

DESCRIPTION These functions shall break a floating-point number num into a normal- ized fraction and an integral power of 2. The integer exponent shall be stored in the int object pointed to by exp.

RETURN VALUE For finite arguments, these functions shall return the value x, such that x has a magnitude in the interval [0.5,1) or 0, and num equals x times 2 raised to the power *exp.

If num is NaN, a NaN shall be returned, and the value of *exp is unspecified.

If num is ±0, ±0 shall be returned, and the value of *exp shall be 0.

If num is ±Inf, num shall be returned, and the value of *exp is unspec- ified.

ERRORS No errors are defined.

The following sections are informative.





SEE ALSO isnan(), ldexp(), modf(), the Base Definitions volume of IEEE Std 1003.1-2001, <math.h>


IEEE/The Open Group 2003 FREXP(3P)