math.h

标准c库代码,可以应用于各个系统提供了大量的基本函数

/* math.h -- Definitions for the math floating point package.  */

#ifndef  _MATH_H_
#ifdef __cplusplus
extern "C" {
#endif
#define  _MATH_H_

#include <sys/reent.h>
#include <machine/ieeefp.h>
#include "_ansi.h"

#ifndef HUGE_VAL

/* Define HUGE_VAL as infinity, unless HUGE_VAL is already defined
   (which might have been done by something like math-68881.h).  */

union __dmath
{
  __uint32_t i[2];
  double d;
};

extern const union __dmath __infinity;

#define HUGE_VAL (__infinity.d)

#endif /* ! defined (HUGE_VAL) */

/* Reentrant ANSI C functions.  */

#ifndef __math_68881
extern double atan _PARAMS((double));
extern double cos _PARAMS((double));
extern double sin _PARAMS((double));
extern double tan _PARAMS((double));
extern double tanh _PARAMS((double));
extern double frexp _PARAMS((double, int *));
extern double modf _PARAMS((double, double *));
extern double ceil _PARAMS((double));
extern double fabs _PARAMS((double));
extern double floor _PARAMS((double));
#endif /* ! defined (__math_68881) */

/* Non reentrant ANSI C functions.  */

#ifndef _REENT_ONLY
#ifndef __math_6881
extern double acos _PARAMS((double));
extern double asin _PARAMS((double));
extern double atan2 _PARAMS((double, double));
extern double cosh _PARAMS((double));
extern double sinh _PARAMS((double));
extern double exp _PARAMS((double));
extern double ldexp _PARAMS((double, int));
extern double log _PARAMS((double));
extern double log10 _PARAMS((double));
extern double pow _PARAMS((double, double));
extern double sqrt _PARAMS((double));
extern double fmod _PARAMS((double, double));
#endif /* ! defined (__math_68881) */
#endif /* ! defined (_REENT_ONLY) */

#ifndef _STRICT_ANSI

/* Non ANSI double precision functions.  */

extern double infinity _PARAMS((void));
extern double nan _PARAMS((void));
extern int isnan _PARAMS((double));
extern int isinf _PARAMS((double));
extern int finite _PARAMS((double));
extern double copysign _PARAMS((double, double));
extern int ilogb _PARAMS((double));

extern double asinh _PARAMS((double));
extern double cbrt _PARAMS((double));
extern double nextafter _PARAMS((double, double));
extern double rint _PARAMS((double));
extern double scalbn _PARAMS((double, int));

#ifndef __math_68881
extern double log1p _PARAMS((double));
extern double expm1 _PARAMS((double));
#endif /* ! defined (__math_68881) */

#ifndef _REENT_ONLY
extern double acosh _PARAMS((double));
extern double atanh _PARAMS((double));
extern double remainder _PARAMS((double, double));
extern double gamma _PARAMS((double));
extern double gamma_r _PARAMS((double, int *));
extern double lgamma _PARAMS((double));
extern double lgamma_r _PARAMS((double, int *));
extern double erf _PARAMS((double));
extern double erfc _PARAMS((double));
extern double y0 _PARAMS((double));
extern double y1 _PARAMS((double));
extern double yn _PARAMS((int, double));
extern double j0 _PARAMS((double));
extern double j1 _PARAMS((double));
extern double jn _PARAMS((int, double));
#define log2(x) (log (x) / M_LOG2_E)

#ifndef __math_68881
extern double hypot _PARAMS((double, double));
#endif

#endif /* ! defined (_REENT_ONLY) */

/* Reentrant versions of double precision functions.  We define macros
   for the functions which are already reentrant so that users do not
   have to remember which are reentrant and which are not.  */

#define _atan_r(p, x) atan (x)
#define _cos_r(p, x) cos (x)
#define _sin_r(p, x) sin (x)
#define _tan_r(p, x) tan (x)
#define _tanh_r(p, x) tanh (x)
#define _frexp_r(p, x) frexp (x)
#define _modf_r(p, x, py) modf ((x), (py))
#define _ceil_r(p, x) ceil (x)
#define _fabs_r(p, x) fabs (x)
#define _floor_r(p, x) floor (x)

extern double _acos_r _PARAMS((struct _reent *, double));
extern double _asin_r _PARAMS((struct _reent *, double));
extern double _atan2_r _PARAMS((struct _reent *, double, double));
extern double _cosh_r _PARAMS((struct _reent *, double));
extern double _sinh_r _PARAMS((struct _reent *, double));
extern double _exp_r _PARAMS((struct _reent *, double));
extern double _ldexp_r _PARAMS((struct _reent *, double, int));
extern double _log_r _PARAMS((struct _reent *, double));
extern double _log10_r _PARAMS((struct _reent *, double));
extern double _pow_r _PARAMS((struct _reent *, double, double));
extern double _sqrt_r _PARAMS((struct _reent *, double));
extern double _fmod_r _PARAMS((struct _reent *, double, double));

#define _asinh_r(p, x) asinh (x)
#define _cbrt_r(p, x) cbrt (x)
#define _nextafter_r(p, x, y) nextafter ((x), (y))
#define _rint_r(p, x) rint (x)
#define _scalbn_r(p, x, y) scalbn ((x), (y))
#define _log1p_r(p, x) log1p (x)
#define _expm1_r(p, x) expm1 (x)

extern double _acosh_r _PARAMS((struct _reent *, double));
extern double _atanh_r _PARAMS((struct _reent *, double));
extern double _remainder_r _PARAMS((struct _reent *, double, double));
extern double _gamma_r _PARAMS((struct _reent *, double));
extern double _gamma_r_r _PARAMS((struct _reent *, double, int *));
extern double _lgamma_r _PARAMS((struct _reent *, double));
extern double _lgamma_r_r _PARAMS((struct _reent *, double, int *));
extern double _erf_r _PARAMS((struct _reent *, double));
extern double _erfc_r _PARAMS((struct _reent *, double));
extern double _y0_r _PARAMS((struct _reent *, double));
extern double _y1_r _PARAMS((struct _reent *, double));
extern double _yn_r _PARAMS((struct _reent *, int, double));
extern double _j0_r _PARAMS((struct _reent *, double));
extern double _j1_r _PARAMS((struct _reent *, double));
extern double _jn_r _PARAMS((struct _reent *, int, double));
#define _log2_r(p, x) (_log_r ((p), (x)) / M_LOG2_E)
extern double _hypot_r _PARAMS((struct _reent *, double, double));

/* Single precision versions of ANSI functions.  */

extern float atanf _PARAMS((float));
extern float cosf _PARAMS((float));
extern float sinf _PARAMS((float));
extern float tanf _PARAMS((float));
extern float tanhf _PARAMS((float));
extern float frexpf _PARAMS((float, int *));
extern float modff _PARAMS((float, float *));
extern float ceilf _PARAMS((float));
extern float fabsf _PARAMS((float));
extern float floorf _PARAMS((float));

#ifndef _REENT_ONLY
extern float acosf _PARAMS((float));
extern float asinf _PARAMS((float));
extern float atan2f _PARAMS((float, float));
extern float coshf _PARAMS((float));
extern float sinhf _PARAMS((float));
extern float expf _PARAMS((float));
extern float ldexpf _PARAMS((float, int));
extern float logf _PARAMS((float));
extern float log10f _PARAMS((float));
extern float powf _PARAMS((float, float));
extern float sqrtf _PARAMS((float));
extern float fmodf _PARAMS((float, float));
#endif /* ! defined (_REENT_ONLY) */

/* Other single precision functions.  */

extern float infinityf _PARAMS((void));
extern float nanf _PARAMS((void));
extern int isnanf _PARAMS((float));
extern int isinff _PARAMS((float));
extern int finitef _PARAMS((float));
extern float copysignf _PARAMS((float, float));
extern int ilogbf _PARAMS((float));

extern float asinhf _PARAMS((float));
extern float cbrtf _PARAMS((float));
extern float nextafterf _PARAMS((float, float));
extern float rintf _PARAMS((float));
extern float scalbnf _PARAMS((float, int));
extern float log1pf _PARAMS((float));
extern float expm1f _PARAMS((float));

#ifndef _REENT_ONLY
extern float acoshf _PARAMS((float));
extern float atanhf _PARAMS((float));
extern float remainderf _PARAMS((float, float));
extern float gammaf _PARAMS((float));
extern float gammaf_r _PARAMS((float, int *));
extern float lgammaf _PARAMS((float));
extern float lgammaf_r _PARAMS((float, int *));
extern float erff _PARAMS((float));
extern float erfcf _PARAMS((float));
extern float y0f _PARAMS((float));
extern float y1f _PARAMS((float));
extern float ynf _PARAMS((int, float));
extern float j0f _PARAMS((float));
extern float j1f _PARAMS((float));
extern float jnf _PARAMS((int, float));
#define log2f(x) (logf (x) / (float) M_LOG2_E)
extern float hypotf _PARAMS((float, float));
#endif /* ! defined (_REENT_ONLY) */

/* Reentrant versions of single precision functions.  */

#define _atanf_r(p, x) atanf (x)
#define _cosf_r(p, x) cosf (x)
#define _sinf_r(p, x) sinf (x)
#define _tanf_r(p, x) tanf (x)
#define _tanhf_r(p, x) tanhf (x)
#define _frexpf_r(p, x) frexpf (x)
#define _modff_r(p, x, py) modff ((x), (py))
#define _ceilf_r(p, x) ceilf (x)
#define _fabsf_r(p, x) fabsf (x)
#define _floorf_r(p, x) floorf (x)

extern float _acosf_r _PARAMS((struct _reent *, float));
extern float _asinf_r _PARAMS((struct _reent *, float));
extern float _atan2f_r _PARAMS((struct _reent *, float, float));
extern float _coshf_r _PARAMS((struct _reent *, float));
extern float _sinhf_r _PARAMS((struct _reent *, float));
extern float _expf_r _PARAMS((struct _reent *, float));
extern float _ldexpf_r _PARAMS((struct _reent *, float, int));
extern float _logf_r _PARAMS((struct _reent *, float));
extern float _log10f_r _PARAMS((struct _reent *, float));
extern float _powf_r _PARAMS((struct _reent *, float, float));
extern float _sqrtf_r _PARAMS((struct _reent *, float));
extern float _fmodf_r _PARAMS((struct _reent *, float, float));

#define _asinhf_r(p, x) asinhf (x)
#define _cbrtf_r(p, x) cbrtf (x)
#define _nextafterf_r(p, x, y) nextafterf ((x), (y))
#define _rintf_r(p, x) rintf (x)
#define _scalbnf_r(p, x, y) scalbnf ((x), (y))
#define _log1pf_r(p, x) log1pf (x)
#define _expm1f_r(p, x) expm1f (x)

extern float _acoshf_r _PARAMS((struct _reent *, float));
extern float _atanhf_r _PARAMS((struct _reent *, float));
extern float _remainderf_r _PARAMS((struct _reent *, float, float));
extern float _gammaf_r _PARAMS((struct _reent *, float));
extern float _gammaf_r_r _PARAMS((struct _reent *, float, int *));
extern float _lgammaf_r _PARAMS((struct _reent *, float));
extern float _lgammaf_r_r _PARAMS((struct _reent *, float, int *));
extern float _erff_r _PARAMS((struct _reent *, float));
extern float _erfcf_r _PARAMS((struct _reent *, float));
extern float _y0f_r _PARAMS((struct _reent *, float));
extern float _y1f_r _PARAMS((struct _reent *, float));
extern float _ynf_r _PARAMS((struct _reent *, int, float));
extern float _j0f_r _PARAMS((struct _reent *, float));
extern float _j1f_r _PARAMS((struct _reent *, float));
extern float _jnf_r _PARAMS((struct _reent *, int, float));
#define _log2f_r(p, x) (_logf_r ((p), (x)) / (float) M_LOG2_E)
extern float _hypotf_r _PARAMS((struct _reent *, float, float));

/* The gamma functions use a global variable, signgam.  */

#ifndef _REENT_ONLY
#define signgam (_REENT->_signgam)
#endif

/* The exception structure passed to the matherr routine.  */

struct exception 
{
  int type;
  char *name;
  double arg1;
  double arg2;
  double retval;
  int err;
};

extern int matherr _PARAMS((struct exception *e));

/* Values for the type field of struct exception.  */

#define DOMAIN 1
#define SING 2
#define OVERFLOW 3
#define UNDERFLOW 4
#define TLOSS 5
#define PLOSS 6

/* Useful constants.  */

#define M_E		2.7182818284590452354
#define M_LOG2E		1.4426950408889634074
#define M_LOG10E	0.43429448190325182765
#define M_LN2		0.69314718055994530942
#define M_LN10		2.30258509299404568402
#define M_PI		3.14159265358979323846
#define M_TWOPI         (M_PI * 2.0)
#define M_PI_2		1.57079632679489661923
#define M_PI_4		0.78539816339744830962
#define M_3PI_4		2.3561944901923448370E0
#define M_SQRTPI        1.77245385090551602792981
#define M_1_PI		0.31830988618379067154
#define M_2_PI		0.63661977236758134308
#define M_2_SQRTPI	1.12837916709551257390
#define M_SQRT2		1.41421356237309504880
#define M_SQRT1_2	0.70710678118654752440
#define M_LN2LO         1.9082149292705877000E-10
#define M_LN2HI         6.9314718036912381649E-1
#define M_SQRT3   	1.73205080756887719000
#define M_IVLN10        0.43429448190325182765 /* 1 / log(10) */
#define M_LOG2_E        0.693147180559945309417
#define M_INVLN2        1.4426950408889633870E0  /* 1 / log(2) */

/* Global control over fdlibm error handling.  */

enum __fdlibm_version
{
  __fdlibm_ieee = -1,
  __fdlibm_svid,
  __fdlibm_xopen,
  __fdlibm_posix
};

#define _LIB_VERSION_TYPE enum __fdlibm_version
#define _LIB_VERSION __fdlib_version

extern _LIB_VERSION_TYPE _LIB_VERSION;

#define _IEEE_  __fdlibm_ieee
#define _SVID_  __fdlibm_svid
#define _XOPEN_ __fdlibm_xopen
#define _POSIX_ __fdlibm_posix

#endif /* ! defined (_STRICT_ANSI) */

#ifdef __cplusplus
}
#endif
#endif /* _MATH_H_ */