scalbn(3)

1SCALBLN(3)                 Linux Programmer's Manual                SCALBLN(3)
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NAME

6       scalbn, scalbnf, scalbnl, scalbln, scalblnf, scalblnl - multiply float‐
7       ing-point number by integral power of radix
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SYNOPSIS

10       #include <math.h>
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12       double scalbln(double x, long int exp);
13       float scalblnf(float x, long int exp);
14       long double scalblnl(long double x, long int exp);
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16       double scalbn(double x, int exp);
17       float scalbnf(float x, int exp);
18       long double scalbnl(long double x, int exp);
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20       Link with -lm.
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22   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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24       scalbln(), scalblnf(), scalblnl(): _XOPEN_SOURCE >= 600 ||
25       _ISOC99_SOURCE; or cc -std=c99
26       scalbn(), scalbnf(), scalbnl(): _BSD_SOURCE || _SVID_SOURCE ||
27       _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE; or cc -std=c99
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DESCRIPTION

30       These functions multiply their first argument x by FLT_RADIX  (probably
31       2) to the power of exp, that is:
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33           x * FLT_RADIX ** exp
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35       The definition of FLT_RADIX can be obtained by including <float.h>.
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RETURN VALUE

38       On success, these functions return x * FLT_RADIX ** exp.
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40       If x is a NaN, a NaN is returned.
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42       If x is positive infinity (negative infinity), positive infinity (nega‐
43       tive infinity) is returned.
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45       If x is +0 (-0), +0 (-0) is returned.
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47       If the result overflows, a range error occurs, and the functions return
48       HUGE_VAL,  HUGE_VALF,  or HUGE_VALL, respectively, with a sign the same
49       as x.
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51       If the result underflows, a  range  error  occurs,  and  the  functions
52       return zero, with a sign the same as x.
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ERRORS

55       See  math_error(7) for information on how to determine whether an error
56       has occurred when calling these functions.
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58       The following errors can occur:
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60       Range error, overflow
61              An overflow floating-point exception (FE_OVERFLOW) is raised.
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63       Range error, underflow
64              An underflow floating-point exception (FE_UNDERFLOW) is raised.
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66       These functions do not set errno.
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VERSIONS

69       These functions first appeared in glibc in version 2.1.
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CONFORMING TO

72       C99, POSIX.1-2001.
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NOTES

75       These  functions  differ  from  the  obsolete  functions  described  in
76       scalb(3) in the type of their second argument.  The functions described
77       on this page have a second argument of an integral type, while those in
78       scalb(3) have a second argument of type double.
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80       If  FLT_RADIX equals 2 (which is usual), then scalbn() is equivalent to
81       ldexp(3).
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COLOPHON

87       This page is part of release 3.22 of the Linux  man-pages  project.   A
88       description  of  the project, and information about reporting bugs, can
89       be found at http://www.kernel.org/doc/man-pages/.
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93                                  2008-08-11                        SCALBLN(3)