math(5) math(5)
NAME [Toc] [Back]
math  math functions, constants, and types
SYNOPSIS [Toc] [Back]
#include <math.h>
DESCRIPTION [Toc] [Back]
This file contains declarations of all the functions in the Math
Library (described in Section (3M)).
For Itanium(R)based systems, included in a compilation under the
fpwidetypes option, this file defines the types
extended The Itaniumbased 80bit doubleextended type.
quad An IEEE 754compliant, 128bit floatingpoint type.
On HPUX, quad is a synonym for long double.
It defines the types
float_t A floating type, at least as wide as float. For PARISC,
float_t is float. For Itaniumbased system, if
FLT_EVAL_METHOD equals 0, float_t is float; if
FLT_EVAL_METHOD equals 1, float_t is double; if
FLT_EVAL_METHOD equals 2, float_t is extended.
double_t A floating type, at least as wide as double. For
PARISC, double_t is double. For Itaniumbased
system, if FLT_EVAL_METHOD equals 0 or 1, double_t is
double; if FLT_EVAL_METHOD equals 2, double_t is
extended.
For Itaniumbased system, the value of FLT_EVAL_METHOD is 0, 1, or 2,
according to the use of the compiler option fpeval=float(default), 
fpeval=double, or fpeval=extended.
It defines the following constants, which, for Itaniumbased system,
may be used to initialize statics and aggregates:
NAN A quiet NaN (NotaNumber) value (type float).
INFINITY A positive infinity value (type float).
HUGE_VAL The maximum value (type double) representable in the
double type (IEEE positive infinity).
HUGE_VALF The maximum value (type float) representable in the
float type (IEEE positive infinity).
HUGE_VALL For Itaniumbased system only, the maximum value
(type long double) representable in the long double
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math(5) math(5)
type (IEEE positive infinity).
HUGE_VALW For Itaniumbased system only, the maximum value
(type extended) representable in the extended type
(IEEE positive infinity). To use HUGE_VALW compile
with the fpwidetypes option.
HUGE_VALQ For Itaniumbased system only, equivalent to
HUGE_VALL. To use HUGE_VALQ compile with the
fpwidetypes option.
It defines the following integer constants which give specialcase
values returned by the ilogb() functions:
FP_ILOGB0 Returned by ilogb() if its argument is zero.
FP_ILOGBNAN Returned by ilogb() if its argument is a NaN.
For Itaniumbased system, it defines the following integer constants
which identify the error handling method supported by <math.h>
functions:
MATH_ERRNO Indicates support for the ISO/IEC C99 errno
specification.
MATH_ERREXCEPT [Toc] [Back]
Indicates support for the ISO/IEC C99 exception flag
specification.
math_errhandling
Defined to be MATH_ERRNO if the +Olibmerrno compiler
option (not the default) is used, or defined to be
MATH_ERREXCEPT otherwise.
It defines the following mathematical constants (type double) for user
convenience:
M_E The base of natural logarithms (e).
M_LOG2E The base2 logarithm of e.
M_LOG10E The base10 logarithm of e.
M_LN2 The natural logarithm of 2.
M_LN10 The natural logarithm of 10.
M_PI The ratio of the circumference of a circle to its
diameter. (There are also several fractions of pi,
its reciprocal, and its square root: M_PI_2, M_PI_4,
M_1_PI, M_2_PI, and M_2_SQRTPI).
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math(5) math(5)
M_SQRT2 The positive square root of 2.
M_SQRT1_2 The positive square root of 1/2.
For the definitions of various machinedependent constants, see the
description of the <values.h> header file.
To use one of the types extended or quad, or one of the macros
HUGE_VALW or HUGE_VALQ, compile with the fpwidetypes option.
FILES [Toc] [Back]
/usr/include/math.h
SEE ALSO [Toc] [Back]
intro(3), complex(5), fenv(5), values(5).
STANDARDS CONFORMANCE [Toc] [Back]
<math.h>: SVID3, XPG4.2, ANSI C, ISO/IEC C99
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