frexp [C++ Reference]
Keywords: c,math,frexp
Date: 2009-03-19T23:53:53-0700

## frexp

Syntax:

        #include <cmath>
        double frexp( double num, int* exp );

The function frexp() is used to decompose num into two parts: a mantissa between 0.5 and 1 (returned by the function) and an exponent returned as exp. Scientific notation works like this:

         num = mantissa * (2 ^ exp)

C++ also provides the following overloaded forms:

        #include <cmath>
        float frexp( float num, int* exp ); // same as frexpf() in C99
        long double frexp( long double num, int* exp ); // same as frexpl() in C99

Related Topics: ldexp, modf