Man page - scalbnf(3)

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Manual

scalbln

NAME
LIBRARY
SYNOPSIS
DESCRIPTION
RETURN VALUE
ERRORS
ATTRIBUTES
STANDARDS
HISTORY
HISTORY
NOTES
BUGS
SEE ALSO

NAME

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

LIBRARY

Math library ( libm , -lm )

SYNOPSIS

#include <math.h>

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

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

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

scalbln (), scalblnf (), scalblnl ():
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE

scalbn (), scalbnf (), scalbnl ():
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION

These functions multiply their first argument x by FLT_RADIX (probably 2) to the power of exp , that is:

x * FLT_RADIX ** exp

The definition of FLT_RADIX can be obtained by including <float.h> .

RETURN VALUE

On success, these functions return x * FLT_RADIX ** exp .

If x is a NaN, a NaN is returned.

If x is positive infinity (negative infinity), positive infinity (negative infinity) is returned.

If x is +0 (-0), +0 (-0) is returned.

If the result overflows, a range error occurs, and the functions return HUGE_VAL , HUGE_VALF , or HUGE_VALL , respectively, with a sign the same as x .

If the result underflows, a range error occurs, and the functions return zero, with a sign the same as x .

ERRORS

See math_error (7) for information on how to determine whether an error has occurred when calling these functions.

The following errors can occur:
Range error, overflow

An overflow floating-point exception ( FE_OVERFLOW ) is raised.

Range error, underflow

errno is set to ERANGE . An underflow floating-point exception ( FE_UNDERFLOW ) is raised.

ATTRIBUTES

For an explanation of the terms used in this section, see attributes (7).

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STANDARDS

C11, POSIX.1-2008.

HISTORY

glibc 2.1. C99, POSIX.1-2001.

HISTORY

These functions differ from the obsolete functions described in scalb (3) in the type of their second argument. The functions described on this page have a second argument of an integral type, while those in scalb (3) have a second argument of type double .

NOTES

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

BUGS

Before glibc 2.20, these functions did not set errno for range errors.

SEE ALSO

ldexp (3), scalb (3)