frexp(3C)

NAME

     frexp - extract mantissa and exponent from double  precision
     number

SYNOPSIS

     #include <math.h>

     double frexp(double num, int *exp);

DESCRIPTION

     The frexp() function breaks a floating-point number  into  a
     normalized  fraction  and  an integral power of 2. It stores
     the integer exponent in the int object pointed to by exp.

RETURN VALUES

     The frexp() function returns the value x, such that x  is  a
     double with magnitude in the interval [1/2, 1) or 0, and num
     equals x times 2 raised to the power *exp.

     If num is 0, both parts of the result are 0.

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

     If num is _Inf, num is returned and the  value  of  *exp  is
     unspecified.

USAGE

     An application wishing to check for error situations  should
     set  errno to 0 before calling frexp(). If errno is non-zero
     on return,  or  the  return  value  is  NaN,  an  error  has
     occurred.

ATTRIBUTES

     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | MT-Level                    | MT-Safe                     |
    |_____________________________|_____________________________|

SEE ALSO

     isnan(3M), ldexp(3C), modf(3C), attributes(5)