math.h(3head)

1math.h(3HEAD)                       Headers                      math.h(3HEAD)
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NAME

6       math.h, math - mathematical declarations
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SYNOPSIS

9       #include <math.h>
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DESCRIPTION

13       The <math.h> header includes definitions for the following types:
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15       float_t     A real-floating type at least as wide as float.
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18       double_t    A  real-floating  type  at  least as wide as double, and at
19                   least as wide as float_t.
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23       If FLT_EVAL_METHOD equals 0, float_t and double_t are float and double,
24       respectively.  If  FLT_EVAL_METHOD  equals  1, they are both double. If
25       FLT_EVAL_METHOD equals 2, they are both be long double. Other values of
26       FLT_EVAL_METHOD are implementation-defined.
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29       The <math.h> header provides the following constants. The values are of
30       type double and are accurate within the precision of the double type.
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32       M_E           The base of natural logarithms (e).
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35       M_LOG2E       The base-2 logarithm of e.
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38       M_LOG10E      The base-10 logarithm of e.
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41       M_LN2         The natural logarithm of 2.
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44       M_LN10        The natural logarithm of 10.
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47       M_PI          pi, the ratio of the circumference of  a  circle  to  its
48                     diameter.
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51       M_PI_2        pi/2.
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54       M_PI_4        pi/4.
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57       M_1_PI        1/pi
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60       M_2_PI        2/pi
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63       M_2_SQRTPI    2 over the square root of pi
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66       M_SQRT2       The positive square root of 2.
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69       M_SQRT1_2     The positive square root of 1/2.
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73       The <math.h> header defines the following symbolic constants:
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75       MAXFLOAT     The  maximum  value  of  a  non-infinite  single-precision
76                    floating point number.
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79       HUGE_VAL     A  positive  double  expression,  not  necessarily  repre‐
80                    sentable  as  a  float. Used as an error value returned by
81                    the mathematics library. HUGE_VAL evaluates  to  +infinity
82                    on systems supporting IEEE Std 754-1985.
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85       HUGE_VALF    A  positive  float  constant  expression. Used as an error
86                    value returned by the mathematics library. HUGE_VALF eval‐
87                    uates   to   +infinity  on  systems  supporting  IEEE  Std
88                    754-1985.
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91       HUGE_VALL    A positive long double constant  expression.  Used  as  an
92                    error value returned by the mathematics library. HUGE_VALL
93                    evaluates to +infinity  on  systems  supporting  IEEE  Std
94                    754-1985.
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97       INFINITY     A  constant expression of type float representing positive
98                    or unsigned infinity, if available; else a  positive  con‐
99                    stant of type float that overflows at translation time.
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102       NAN          A  constant  expression of type float representing a quiet
103                    NaN. This symbolic constant is only defined if the  imple‐
104                    mentation supports quiet NaNs for the float type.
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108       The following macros are defined for number classification. They repre‐
109       sent the mutually-exclusive kinds of floating-point values. They expand
110       to integer constant expressions with distinct values
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112         FP_INFINITE
113         FP_NAN
114         FP_NORMAL
115         FP_SUBNORMAL
116         FP_ZERO
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120       The  following  optional  macros  indicate  whether the fma() family of
121       functions are fast compared with direct code:
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123         FP_FAST_FMA
124         FP_FAST_FMAF
125         FP_FAST_FMAL
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129       The FP_FAST_FMA macro is defined to indicate that  the  fma()  function
130       generally  executes about as fast as, or faster than, a multiply and an
131       add of double operands. The other macros have  the  equivalent  meaning
132       for the float and long double versions.
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135       The  following macros expand to integer constant expressions whose val‐
136       ues are returned by ilogb(x) if x is zero  or  NaN,  respectively.  The
137       value  of  FP_ILOGB0  is  either  {INT_MIN} or -{INT_MAX}. The value of
138       FP_ILOGBNAN is either {INT_MAX} or {INT_MIN}.
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140         FP_ILOGB0
141         FP_ILOGBNAN
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145       The following macros expand to the integer constants 1 and  2,  respec‐
146       tively:
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148         MATH_ERRNO
149         MATH_ERREXCEPT
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153       The  following macro expands to an expression that has type int and the
154       value MATH_ERREXCEPT:
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156         math_errhandling
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160       The value of the macro math_errhandling is constant for the duration of
161       the  program.  If a macro definition is suppressed or a program defines
162       an identifier with the name math_errhandling,  the  behavior  is  unde‐
163       fined.
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166       The <math.h> header defines he following external variable:
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168         extern int signgam;
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172       The  <math.h>  header  defines  the structure and constants used by the
173       matherr(3M) error-handling mechanisms.
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ATTRIBUTES

176       See attributes(5) for descriptions of the following attributes:
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181       ┌─────────────────────────────┬─────────────────────────────┐
182       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
183       ├─────────────────────────────┼─────────────────────────────┤
184       │Interface Stability          │Standard                     │
185       └─────────────────────────────┴─────────────────────────────┘
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NAME

SYNOPSIS

DESCRIPTION

ATTRIBUTES

SEE ALSO