frexp, frexpf, frexpl: převést číslo s pohyblivou řádovou čárkou na zlomkové a integrální komponenty

Originální popis anglicky: frexp, frexpf, frexpl - convert floating-point number to fractional and integral components

Návod, kniha: Linux Programmer's Manual

STRUČNĚ

#include <math.h>
 
double frexp(double x, int *exp);
 
float frexpf(float x, int *exp);
 
long double frexpl(long double x, int *exp);

Link with -lm.

POPIS / INSTRUKCE

The frexp() function is used to split the number x into a normalized fraction and an exponent which is stored in exp.

NÁVRATOVÁ HODNOTA

The frexp() function returns the normalized fraction. If the argument x is not zero, the normalized fraction is x times a power of two, and is always in the range 1/2 (inclusive) to 1 (exclusive). If x is zero, then the normalized fraction is zero and zero is stored in exp.

ODPOVÍDAJÍCÍ

SVID 3, POSIX, BSD 4.3, ISO 9899. The float and the long double variants are C99 requirements.

EXAMPLE

#include <stdio.h>
#include <math.h>
#include <float.h>
int main () {
        double d = 2560;
        int e;
        double f = frexp(d, &e);
        printf("frexp(%g, &e) = %g: %g * %d^%d = %g\n",
               d, f, f, FLT_RADIX, e, d);
        return 0;
}

This program prints
frexp(2560, &e) = 0.625: 0.625 * 2^12 = 2560

SOUVISEJÍCÍ

ldexp(3), modf(3)