GNU/Linux man pages
Livre :
Expressions régulières,
Syntaxe et mise en oeuvre :
GNU/Linux |
Debian 6.0.6(Squeeze) |
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scalbnf(3) |
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scalbn, scalbnf, scalbnl, scalbln, scalblnf, scalblnl − multiply floating-point number by integral power of radix
#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():
_XOPEN_SOURCE >= 600
|| _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
scalbn(), scalbnf(), scalbnl():
_BSD_SOURCE || _SVID_SOURCE ||
_XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
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>.
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.
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.
These functions first appeared in glibc in version 2.1.
C99, POSIX.1-2001.
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).
ldexp(3), scalb(3)
This page is part of release 3.27 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/.
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scalbnf(3) | |