cpython/Modules/mathmodule.c

/***********************************************************
Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
The Netherlands.

                        All Rights Reserved

Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
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permission.

While CWI is the initial source for this software, a modified version
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(CNRI) at the Internet address ftp://ftp.python.org.

STICHTING MATHEMATISCH CENTRUM AND CNRI DISCLAIM ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF
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******************************************************************/

/* Math module -- standard C math library functions, pi and e */

#include "Python.h"

#include "mymath.h"

#ifndef _MSC_VER
#ifndef __STDC__
extern double fmod Py_PROTO((double, double));
extern double frexp Py_PROTO((double, int *));
extern double ldexp Py_PROTO((double, int));
extern double modf Py_PROTO((double, double *));
#endif /* __STDC__ */
#endif /* _MSC_VER */


#ifdef i860
/* Cray APP has bogus definition of HUGE_VAL in <math.h> */
#undef HUGE_VAL
#endif

#ifdef HUGE_VAL
#define CHECK(x) if (errno != 0) ; \
	else if (-HUGE_VAL <= (x) && (x) <= HUGE_VAL) ; \
	else errno = ERANGE
#else
#define CHECK(x) /* Don't know how to check */
#endif

static PyObject *
math_error()
{
	if (errno == EDOM)
		PyErr_SetString(PyExc_ValueError, "math domain error");
	else if (errno == ERANGE)
		PyErr_SetString(PyExc_OverflowError, "math range error");
	else
                /* Unexpected math error */
		PyErr_SetFromErrno(PyExc_ValueError);
	return NULL;
}

static PyObject *
math_1(args, func)
	PyObject *args;
	double (*func) Py_FPROTO((double));
{
	double x;
	if (!  PyArg_Parse(args, "d", &x))
		return NULL;
	errno = 0;
	PyFPE_START_PROTECT("in math_1", return 0)
	x = (*func)(x);
	PyFPE_END_PROTECT(x)
	CHECK(x);
	if (errno != 0)
		return math_error();
	else
		return PyFloat_FromDouble(x);
}

static PyObject *
math_2(args, func)
	PyObject *args;
	double (*func) Py_FPROTO((double, double));
{
	double x, y;
	if (! PyArg_Parse(args, "(dd)", &x, &y))
		return NULL;
	errno = 0;
	PyFPE_START_PROTECT("in math_2", return 0)
	x = (*func)(x, y);
	PyFPE_END_PROTECT(x)
	CHECK(x);
	if (errno != 0)
		return math_error();
	else
		return PyFloat_FromDouble(x);
}

#define FUNC1(stubname, func) \
	static PyObject * stubname(self, args) PyObject *self, *args; { \
		return math_1(args, func); \
	}

#define FUNC2(stubname, func) \
	static PyObject * stubname(self, args) PyObject *self, *args; { \
		return math_2(args, func); \
	}

FUNC1(math_acos, acos)
FUNC1(math_asin, asin)
FUNC1(math_atan, atan)
FUNC2(math_atan2, atan2)
FUNC1(math_ceil, ceil)
FUNC1(math_cos, cos)
FUNC1(math_cosh, cosh)
FUNC1(math_exp, exp)
#ifdef __MWERKS__
double myfabs(double x) { return fabs(x); }
FUNC1(math_fabs, myfabs)
#else
FUNC1(math_fabs, fabs)
#endif
FUNC1(math_floor, floor)
FUNC2(math_fmod, fmod)
FUNC2(math_hypot, hypot)
FUNC1(math_log, log)
FUNC1(math_log10, log10)
#ifdef MPW_3_1 /* This hack is needed for MPW 3.1 but not for 3.2 ... */
FUNC2(math_pow, power)
#else
FUNC2(math_pow, pow)
#endif
FUNC1(math_sin, sin)
FUNC1(math_sinh, sinh)
FUNC1(math_sqrt, sqrt)
FUNC1(math_tan, tan)
FUNC1(math_tanh, tanh)


static PyObject *
math_frexp(self, args)
	PyObject *self;
	PyObject *args;
{
	double x;
	int i;
	if (! PyArg_Parse(args, "d", &x))
		return NULL;
	errno = 0;
	x = frexp(x, &i);
	CHECK(x);
	if (errno != 0)
		return math_error();
	return Py_BuildValue("(di)", x, i);
}

static PyObject *
math_ldexp(self, args)
	PyObject *self;
	PyObject *args;
{
	double x, y;
	/* Cheat -- allow float as second argument */
        if (! PyArg_Parse(args, "(dd)", &x, &y))
		return NULL;
	errno = 0;
	PyFPE_START_PROTECT("ldexp", return 0)
	x = ldexp(x, (int)y);
	PyFPE_END_PROTECT(x)
	CHECK(x);
	if (errno != 0)
		return math_error();
	else
		return PyFloat_FromDouble(x);
}

static PyObject *
math_modf(self, args)
	PyObject *self;
	PyObject *args;
{
	double x, y;
	if (! PyArg_Parse(args, "d", &x))
		return NULL;
	errno = 0;
#ifdef MPW /* MPW C modf expects pointer to extended as second argument */
{
	extended e;
	x = modf(x, &e);
	y = e;
}
#else
	x = modf(x, &y);
#endif
	CHECK(x);
	if (errno != 0)
		return math_error();
	return Py_BuildValue("(dd)", x, y);
}

static PyMethodDef math_methods[] = {
	{"acos", math_acos},
	{"asin", math_asin},
	{"atan", math_atan},
	{"atan2", math_atan2},
	{"ceil", math_ceil},
	{"cos", math_cos},
	{"cosh", math_cosh},
	{"exp", math_exp},
	{"fabs", math_fabs},
	{"floor", math_floor},
	{"fmod", math_fmod},
	{"frexp", math_frexp},
	{"hypot", math_hypot},
	{"ldexp", math_ldexp},
	{"log", math_log},
	{"log10", math_log10},
	{"modf", math_modf},
	{"pow", math_pow},
	{"sin", math_sin},
	{"sinh", math_sinh},
	{"sqrt", math_sqrt},
	{"tan", math_tan},
	{"tanh", math_tanh},
	{NULL,		NULL}		/* sentinel */
};

void
initmath()
{
	PyObject *m, *d, *v;
	
	m = Py_InitModule("math", math_methods);
	d = PyModule_GetDict(m);

        if (!(v = PyFloat_FromDouble(atan(1.0) * 4.0)))
                goto finally;
	if (PyDict_SetItemString(d, "pi", v) < 0)
                goto finally;
	Py_DECREF(v);

        if (!(v = PyFloat_FromDouble(exp(1.0))))
                goto finally;
	if (PyDict_SetItemString(d, "e", v) < 0)
                goto finally;
	Py_DECREF(v);
	return;

  finally:
        Py_FatalError("can't initialize math module");
}