scalb

Autres langues

Langue: en

Version: 2007-07-26 (openSuse - 09/10/07)

Section: 3 (Bibliothèques de fonctions)

NAME

scalb, scalbf, scalbl, scalbn, scalbnf, scalbnl, scalbln, scalblnf, scalblnl - multiply floating-point number by integral power of radix

SYNOPSIS

#include <math.h>

double scalb(double x, double exp);
float scalbf(float x, double exp);
long double scalbl(long double x, double exp);

double scalbn(double x, int exp);
float scalbnf(float x, int exp);
long double scalbnl(long double x, int exp);

double scalbln(double x, long int exp);
float scalblnf(float x, long int exp);
long double scalblnl(long double x, long int exp);

Link with -lm.

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

scalb(), scalbf(), scalbl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500
scalbn(), scalbnf(), scalbnl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99
scalbln(), scalblnf(), scalblnl(): _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99

DESCRIPTION

These functions multiply their first argument x by FLT_RADIX (probably 2) to the power exp.

If FLT_RADIX equals 2, then scalbn() is equivalent to ldexp(3).

The value of FLT_RADIX is found in <float.h>.

CONFORMING TO

The scalb() function is from 4.3BSD. The scalbn() and scalbln() functions are from C99. All three are in POSIX.1-2001. The scalb() function is marked obsolescent.

SEE ALSO

ldexp(3)