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SCALBLN(3) | Linux Programmer's Manual | SCALBLN(3) |
NAME¶
scalbn, scalbnf, scalbnl, scalbln, scalblnf, scalblnl - multiply floating-point number by integral power of radixSYNOPSIS¶
#include <math.h> double scalbln(double x, long 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
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
_ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* Glibc versions <= 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 ** expThe 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.
VERSIONS¶
These functions first appeared in glibc in version 2.1.ATTRIBUTES¶
For an explanation of the terms used in this section, see attributes(7).Interface | Attribute | Value |
scalbn (), scalbnf (), scalbnl (), scalbln (), scalblnf (), scalblnl () | Thread safety | MT-Safe |
CONFORMING TO¶
C99, POSIX.1-2001, POSIX.1-2008.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 4.10 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.2016-03-15 |