1SCALB(3)                   Linux Programmer's Manual                  SCALB(3)
2
3
4

NAME

6       scalb,  scalbf,  scalbl  -  multiply  floating-point number by integral
7       power of radix (OBSOLETE)
8

SYNOPSIS

10       #include <math.h>
11
12       double scalb(double x, double exp);
13       float scalbf(float x, float exp);
14       long double scalbl(long double x, long double exp);
15
16       Link with -lm.
17
18   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
19
20       scalb():
21           _XOPEN_SOURCE >= 500
22               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
23               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
24       scalbf(), scalbl():
25           _XOPEN_SOURCE >= 600
26               || /* Since glibc 2.19: */ _DEFAULT_SOURCE
27               || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
28

DESCRIPTION

30       These functions multiply their first argument x by FLT_RADIX  (probably
31       2) to the power of exp, that is:
32
33           x * FLT_RADIX ** exp
34
35       The definition of FLT_RADIX can be obtained by including <float.h>.
36

RETURN VALUE

38       On success, these functions return x * FLT_RADIX ** exp.
39
40       If x or exp is a NaN, a NaN is returned.
41
42       If  x is positive infinity (negative infinity), and exp is not negative
43       infinity, positive infinity (negative infinity) is returned.
44
45       If x is +0 (-0), and exp is not positive infinity, +0 (-0) is returned.
46
47       If x is zero, and exp is positive infinity, a domain error occurs,  and
48       a NaN is returned.
49
50       If  x  is  an  infinity,  and  exp is negative infinity, a domain error
51       occurs, and a NaN is returned.
52
53       If the result overflows, a range error occurs, and the functions return
54       HUGE_VAL,  HUGE_VALF,  or HUGE_VALL, respectively, with a sign the same
55       as x.
56
57       If the result underflows, a  range  error  occurs,  and  the  functions
58       return zero, with a sign the same as x.
59

ERRORS

61       See  math_error(7) for information on how to determine whether an error
62       has occurred when calling these functions.
63
64       The following errors can occur:
65
66       Domain error: x is 0, and exp is positive infinity, or  x  is  positive
67       infinity  and  exp is negative infinity and the other argument is not a
68       NaN
69              An invalid floating-point exception (FE_INVALID) is raised.
70
71       Range error, overflow
72              An overflow floating-point exception (FE_OVERFLOW) is raised.
73
74       Range error, underflow
75              An underflow floating-point exception (FE_UNDERFLOW) is raised.
76
77       These functions do not set errno.
78

ATTRIBUTES

80       For  an  explanation  of  the  terms  used   in   this   section,   see
81       attributes(7).
82
83       ┌─────────────────────────────┬───────────────┬─────────┐
84Interface                    Attribute     Value   
85       ├─────────────────────────────┼───────────────┼─────────┤
86scalb(), scalbf(), scalbl()  │ Thread safety │ MT-Safe │
87       └─────────────────────────────┴───────────────┴─────────┘

CONFORMING TO

89       scalb()   is   specified   in  POSIX.1-2001,  but  marked  obsolescent.
90       POSIX.1-2008 removes the specification of scalb(), recommending the use
91       of  scalbln(3), scalblnf(3), or scalblnl(3) instead.  The scalb() func‐
92       tion is from 4.3BSD.
93
94       scalbf() and scalbl()  are  unstandardized;  scalbf()  is  nevertheless
95       present on several other systems
96

SEE ALSO

98       ldexp(3), scalbln(3)
99

COLOPHON

101       This  page  is  part of release 5.02 of the Linux man-pages project.  A
102       description of the project, information about reporting bugs,  and  the
103       latest     version     of     this    page,    can    be    found    at
104       https://www.kernel.org/doc/man-pages/.
105
106
107
108                                  2017-09-15                          SCALB(3)
Impressum