scalbln(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 exp);
13       float scalblnf(float x, long exp);
14       long double scalblnl(long double x, long 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():
25           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
26               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
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28       scalbn(), scalbnf(), scalbnl():
29           _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
30               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
31               || /* Glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
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DESCRIPTION

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

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

59       See  math_error(7) for information on how to determine whether an error
60       has occurred when calling these functions.
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62       The following errors can occur:
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64       Range error, overflow
65              An overflow floating-point exception (FE_OVERFLOW) is raised.
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67       Range error, underflow
68              errno is set to ERANGE.  An underflow  floating-point  exception
69              (FE_UNDERFLOW) is raised.
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VERSIONS

72       These functions first appeared in glibc in version 2.1.
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ATTRIBUTES

75       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
76       tributes(7).
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78       ┌────────────────────────────────────────────┬───────────────┬─────────┐
79       │Interface                                   │ Attribute     │ Value   │
80       ├────────────────────────────────────────────┼───────────────┼─────────┤
81       │scalbn(), scalbnf(), scalbnl(), scalbln(),  │ Thread safety │ MT-Safe │
82       │scalblnf(), scalblnl()                      │               │         │
83       └────────────────────────────────────────────┴───────────────┴─────────┘
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CONFORMING TO

86       C99, POSIX.1-2001, POSIX.1-2008.
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NOTES

89       These  functions  differ  from  the  obsolete  functions  described  in
90       scalb(3) in the type of their second argument.  The functions described
91       on this page have a second argument of an integral type, while those in
92       scalb(3) have a second argument of type double.
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94       If FLT_RADIX equals 2 (which is usual), then scalbn() is equivalent  to
95       ldexp(3).
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BUGS

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

104       This  page  is  part of release 5.12 of the Linux man-pages project.  A
105       description of the project, information about reporting bugs,  and  the
106       latest     version     of     this    page,    can    be    found    at
107       https://www.kernel.org/doc/man-pages/.
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111                                  2021-03-22                        SCALBLN(3)