Tribblix: manual page: math.h.3head

MATH.H(3HEAD) Headers MATH.H(3HEAD)

NAME

math.h, math - mathematical declarations

SYNOPSIS

#include <math.h>

DESCRIPTION

The <math.h> header includes definitions for the following types:

float_t
A real-floating type at least as wide as float.

double_t
A real-floating type at least as wide as double, and at
least as wide as float_t.

If FLT_EVAL_METHOD equals 0, float_t and double_t are float and
double, respectively. If FLT_EVAL_METHOD equals 1, they are both
double. If FLT_EVAL_METHOD equals 2, they are both be long double.
Other values of FLT_EVAL_METHOD are implementation-defined.

The <math.h> header provides the following constants. The values are
of type double and are accurate within the precision of the double
type.

M_E
The base of natural logarithms (e).

M_LOG2E
The base-2 logarithm of e.

M_LOG10E
The base-10 logarithm of e.

M_LN2
The natural logarithm of 2.

M_LN10
The natural logarithm of 10.

M_PI
pi, the ratio of the circumference of a circle to its
diameter.

M_PI_2
pi/2.

M_PI_4
pi/4.

M_1_PI
1/pi

M_2_PI
2/pi

M_2_SQRTPI
2 over the square root of pi

M_SQRT2
The positive square root of 2.

M_SQRT1_2
The positive square root of 1/2.

The <math.h> header defines the following symbolic constants:

MAXFLOAT
The maximum value of a non-infinite single-precision
floating point number.

HUGE_VAL
A positive double expression, not necessarily
representable as a float. Used as an error value
returned by the mathematics library. HUGE_VAL evaluates
to +infinity on systems supporting IEEE Std 754-1985.

HUGE_VALF
A positive float constant expression. Used as an error
value returned by the mathematics library. HUGE_VALF
evaluates to +infinity on systems supporting IEEE Std
754-1985.

HUGE_VALL
A positive long double constant expression. Used as an
error value returned by the mathematics library.
HUGE_VALL evaluates to +infinity on systems supporting
IEEE Std 754-1985.

INFINITY
A constant expression of type float representing
positive or unsigned infinity, if available; else a
positive constant of type float that overflows at
translation time.

NAN
A constant expression of type float representing a quiet
NaN. This symbolic constant is only defined if the
implementation supports quiet NaNs for the float type.

The following macros are defined for number classification. They
represent the mutually-exclusive kinds of floating-point values. They
expand to integer constant expressions with distinct values

FP_INFINITE
FP_NAN
FP_NORMAL
FP_SUBNORMAL
FP_ZERO

The following optional macros indicate whether the fma() family of
functions are fast compared with direct code:

FP_FAST_FMA
FP_FAST_FMAF
FP_FAST_FMAL

The FP_FAST_FMA macro is defined to indicate that the fma() function
generally executes about as fast as, or faster than, a multiply and
an add of double operands. The other macros have the equivalent
meaning for the float and long double versions.

The following macros expand to integer constant expressions whose
values are returned by ilogb(x) if x is zero or NaN, respectively.
The value of FP_ILOGB0 is either {INT_MIN} or -{INT_MAX}. The value
of FP_ILOGBNAN is either {INT_MAX} or {INT_MIN}.

FP_ILOGB0
FP_ILOGBNAN

The following macros expand to the integer constants 1 and 2,
respectively:

MATH_ERRNO
MATH_ERREXCEPT

The following macro expands to an expression that has type int and
the value MATH_ERREXCEPT:

math_errhandling

The value of the macro math_errhandling is constant for the duration
of the program. If a macro definition is suppressed or a program
defines an identifier with the name math_errhandling, the behavior is
undefined.

The <math.h> header defines the following external variable:

extern int signgam;

The <math.h> header defines the structure and constants used by the
matherr(3M) error-handling mechanisms.

ATTRIBUTES

NAME

SYNOPSIS

DESCRIPTION

ATTRIBUTES

SEE ALSO