log10(3m) - osol9

1log10(3M)               Mathematical Library Functions               log10(3M)
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NAME

6       log10, log10f, log10l - base 10 logarithm function
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SYNOPSIS

9       c99 [ flag... ] file... -lm [ library... ]
10       #include <math.h>
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12       double log10(double x);
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15       float log10f(float x);
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18       long double log10l(long double x);
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DESCRIPTION

22       These functions compute the base 10 logarithm of x, log(10)(x).
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RETURN VALUES

25       Upon successful completion, log10() returns the base 10 logarithm of x.
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28       If  x  is  ±0,  a pole error occurs and log10(), log10f(), and log10l()
29       return −HUGE_VAL, −HUGE_VALF, and −HUGE_VALL, respectively.
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32       For finite values of x that are less than 0, or if x is −Inf, a  domain
33       error occurs and a NaN is returned.
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36       If x is NaN, a NaN is returned.
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39       If x is 1, +0 is returned.
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42       If x is +Inf, x is returned.
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45       For  exceptional cases, matherr(3M) tabulates the values to be returned
46       by log10() as specified by SVID3 and XPG3.
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ERRORS

49       These functions will fail if:
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51       Domain Error    The finite value of x is negative, or x is -Inf.
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53                       If   the   integer   expression   (math_errhandling   &
54                       MATH_ERREXCEPT) is non-zero, the invalid floating-point
55                       exception is raised.
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57                       The log10() function sets errno to EDOM if the value of
58                       x is negative.
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61       Pole Error      The value of x is 0.
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63                       If   the   integer   expression   (math_errhandling   &
64                       MATH_ERREXCEPT) is non-zero, the divide-by-zero  float‐
65                       ing-point exception is raised.
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USAGE

69       An  application  wanting to check for exceptions should call feclearex‐
70       cept(FE_ALL_EXCEPT) before  calling  these  functions.  On  return,  if
71       fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is
72       non-zero, an exception has been raised. An  application  should  either
73       examine the return value or check the floating point exception flags to
74       detect exceptions.
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77       An application can also set errno  to  0  before  calling  log10().  On
78       return,  if  errno is non-zero, an error has occurred. The log10f() and
79       log10l() functions do not set errno.
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ATTRIBUTES

82       See attributes(5) for descriptions of the following attributes:
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87       ┌─────────────────────────────┬─────────────────────────────┐
88       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
89       ├─────────────────────────────┼─────────────────────────────┤
90       │Interface Stability          │Standard                     │
91       ├─────────────────────────────┼─────────────────────────────┤
92       │MT-Level                     │MT-Safe                      │
93       └─────────────────────────────┴─────────────────────────────┘
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