# frexp, frexpl

Remonter à Math.h - Index

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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