NAME¶

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

SYNOPSIS¶

#include <math.h> double scalbln(double x, long int exp); float scalblnf(float x, long int exp); long double scalblnl(long double x, long int exp); double scalbn(double x, int exp); float scalbnf(float x, int exp); long double scalbnl(long double x, int exp); Link with -lm.
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
scalbln(), scalblnf(), scalblnl(): scalbn(), scalbnf(), scalbnl():

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

An underflow floating-point exception (FE_UNDERFLOW) is raised.

These functions do not set errno.

VERSIONS¶

These functions first appeared in glibc in version 2.1.

CONFORMING TO¶

C99, POSIX.1-2001.

NOTES¶

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

SEE ALSO¶

ldexp(3), scalb(3)

COLOPHON¶

This page is part of release 3.44 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.