frexp, frexpl

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Header File

math.h

Category

Math Routines

Prototype

double frexp(double x, int *exponent);

long double frexpl(long double x, int *exponent);

Description

Splits a number into mantissa and exponent.

frexp calculates the mantissa m (a double greater than or equal to 0.5 and less than 1) and the integer value n such that x (the original double value) equals m * 2n. frexp stores n in the integer that exponent points to.

frexpl is the long double version; it takes a long double argument for x and returns a long double result.

Return Value

frexp and frexpl return the mantissa m. Error handling for these routines can be modified through the functions _matherr and _matherrl.

Example



 #include <math.h>
 #include <stdio.h>
 int main(void)
 {
    double mantissa, number;
    int exponent;
    number = 8.0;
    mantissa = frexp(number, &exponent);
    printf("The number %lf is ", number);
    printf("%lf times two to the ", mantissa);
    printf("power of %d\n", exponent);
    return 0;
 }



Portability



POSIX Win32 ANSI C ANSI C++

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