scalbf(3)

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

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

10       #include <math.h>
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12       double scalb(double x, double exp);
13       float scalbf(float x, double exp);
14       long double scalbl(long double x, double exp);
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16       Link with -lm.
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18   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
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20       scalb(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500
21       scalbf(), scalbl(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600
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DESCRIPTION

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

32       On success, these functions return x * FLT_RADIX ** exp.
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34       If x or exp is a NaN, a NaN is returned.
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36       If  x is positive infinity (negative infinity), and exp is not negative
37       infinity, positive infinity (negative infinity) is returned.
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39       If x is +0 (-0), and exp is not positive infinity, +0 (-0) is returned.
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41       If x is zero, and exp is positive infinity, a domain error occurs,  and
42       a NaN is returned.
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44       If  x  is  an  infinity,  and  exp is negative infinity, a domain error
45       occurs, and a NaN 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       Domain error: x is 0, and exp is positive infinity, or  x  is  positive
61       infinity  and  exp is negative infinity and the other argument is not a
62       NaN
63              An invalid floating-point exception (FE_INVALID) is raised.
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65       Range error, overflow
66              An overflow floating-point exception (FE_OVERFLOW) is raised.
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68       Range error, underflow
69              An underflow floating-point exception (FE_UNDERFLOW) is raised.
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71       These functions do not set errno.
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CONFORMING TO

74       scalb()  is  specified  in  POSIX.1-2001,   but   marked   obsolescent.
75       POSIX.1-2008 removes the specification of scalb(), recommending the use
76       of scalbln(3), scalblnf(3), or scalblnl(3) instead.  The scalb()  func‐
77       tion is from 4.3BSD.
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79       scalbf()  and  scalbl()  are  unstandardized;  scalbf() is nevertheless
80       present on several other systems
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COLOPHON

86       This page is part of release 3.25 of the Linux  man-pages  project.   A
87       description  of  the project, and information about reporting bugs, can
88       be found at http://www.kernel.org/doc/man-pages/.
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92                                  2009-03-15                          SCALB(3)