Modules/cmathmodule.c

   1 /* Complex math module */
   2
   3 /* much code borrowed from mathmodule.c */
   4
   5 #include "Python.h"
   6
   7 #include "mymath.h"
   8
   9 #ifdef i860
  10 /* Cray APP has bogus definition of HUGE_VAL in <math.h> */
  11 #undef HUGE_VAL
  12 #endif
  13
  14 #ifdef HUGE_VAL
  15 #define CHECK(x) if (errno != 0) ; \
  16         else if (-HUGE_VAL <= (x) && (x) <= HUGE_VAL) ; \
  17         else errno = ERANGE
  18 #else
  19 #define CHECK(x) /* Don't know how to check */
  20 #endif
  21
  22 #ifndef M_PI
  23 #define M_PI (3.141592653589793239)
  24 #endif
  25
  26 /* First, the C functions that do the real work */
  27
  28 /* constants */
  29 static Py_complex c_1 = {1., 0.};
  30 static Py_complex c_half = {0.5, 0.};
  31 static Py_complex c_i = {0., 1.};
  32 static Py_complex c_i2 = {0., 0.5};
  33 #if 0
  34 static Py_complex c_mi = {0., -1.};
  35 static Py_complex c_pi2 = {M_PI/2., 0.};
  36 #endif
  37
  38 /* forward declarations */
  39 staticforward Py_complex c_log();
  40 staticforward Py_complex c_prodi();
  41 staticforward Py_complex c_sqrt();
  42
  43
  44 static Py_complex c_acos(x)
  45         Py_complex x;
  46 {
  47         return c_neg(c_prodi(c_log(c_sum(x,c_prod(c_i,
  48                     c_sqrt(c_diff(c_1,c_prod(x,x))))))));
  49 }
  50
  51 static Py_complex c_acosh(x)
  52         Py_complex x;
  53 {
  54         return c_log(c_sum(x,c_prod(c_i,
  55                     c_sqrt(c_diff(c_1,c_prod(x,x))))));
  56 }
  57
  58 static Py_complex c_asin(x)
  59         Py_complex x;
  60 {
  61         return c_neg(c_prodi(c_log(c_sum(c_prod(c_i,x),
  62                     c_sqrt(c_diff(c_1,c_prod(x,x)))))));
  63 }
  64
  65 static Py_complex c_asinh(x)
  66         Py_complex x;
  67 {
  68         return c_neg(c_log(c_diff(c_sqrt(c_sum(c_1,c_prod(x,x))),x)));
  69 }
  70
  71 static Py_complex c_atan(x)
  72         Py_complex x;
  73 {
  74         return c_prod(c_i2,c_log(c_quot(c_sum(c_i,x),c_diff(c_i,x))));
  75 }
  76
  77 static Py_complex c_atanh(x)
  78         Py_complex x;
  79 {
  80         return c_prod(c_half,c_log(c_quot(c_sum(c_1,x),c_diff(c_1,x))));
  81 }
  82
  83 static Py_complex c_cos(x)
  84         Py_complex x;
  85 {
  86         Py_complex r;
  87         r.real = cos(x.real)*cosh(x.imag);
  88         r.imag = -sin(x.real)*sinh(x.imag);
  89         return r;
  90 }
  91
  92 static Py_complex c_cosh(x)
  93         Py_complex x;
  94 {
  95         Py_complex r;
  96         r.real = cos(x.imag)*cosh(x.real);
  97         r.imag = sin(x.imag)*sinh(x.real);
  98         return r;
  99 }
 100
 101 static Py_complex c_exp(x)
 102         Py_complex x;
 103 {
 104         Py_complex r;
 105         double l = exp(x.real);
 106         r.real = l*cos(x.imag);
 107         r.imag = l*sin(x.imag);
 108         return r;
 109 }
 110
 111 static Py_complex c_log(x)
 112         Py_complex x;
 113 {
 114         Py_complex r;
 115         double l = hypot(x.real,x.imag);
 116         r.imag = atan2(x.imag, x.real);
 117         r.real = log(l);
 118         return r;
 119 }
 120
 121 static Py_complex c_log10(x)
 122         Py_complex x;
 123 {
 124         Py_complex r;
 125         double l = hypot(x.real,x.imag);
 126         r.imag = atan2(x.imag, x.real)/log(10.);
 127         r.real = log10(l);
 128         return r;
 129 }
 130
 131 static Py_complex c_prodi(x)
 132      Py_complex x;
 133 {
 134         Py_complex r;
 135         r.real = -x.imag;
 136         r.imag = x.real;
 137         return r;
 138 }
 139
 140 static Py_complex c_sin(x)
 141         Py_complex x;
 142 {
 143         Py_complex r;
 144         r.real = sin(x.real)*cosh(x.imag);
 145         r.imag = cos(x.real)*sinh(x.imag);
 146         return r;
 147 }
 148
 149 static Py_complex c_sinh(x)
 150         Py_complex x;
 151 {
 152         Py_complex r;
 153         r.real = cos(x.imag)*sinh(x.real);
 154         r.imag = sin(x.imag)*cosh(x.real);
 155         return r;
 156 }
 157
 158 static Py_complex c_sqrt(x)
 159         Py_complex x;
 160 {
 161         Py_complex r;
 162         double s,d;
 163         if (x.real == 0. && x.imag == 0.)
 164                 r = x;
 165         else {
 166                 s = sqrt(0.5*(fabs(x.real) + hypot(x.real,x.imag)));
 167                 d = 0.5*x.imag/s;
 168                 if (x.real > 0.) {
 169                         r.real = s;
 170                         r.imag = d;
 171                 }
 172                 else if (x.imag >= 0.) {
 173                         r.real = d;
 174                         r.imag = s;
 175                 }
 176                 else {
 177                         r.real = -d;
 178                         r.imag = -s;
 179                 }
 180         }
 181         return r;
 182 }
 183
 184 static Py_complex c_tan(x)
 185         Py_complex x;
 186 {
 187         Py_complex r;
 188         double sr,cr,shi,chi;
 189         double rs,is,rc,ic;
 190         double d;
 191         sr = sin(x.real);
 192         cr = cos(x.real);
 193         shi = sinh(x.imag);
 194         chi = cosh(x.imag);
 195         rs = sr*chi;
 196         is = cr*shi;
 197         rc = cr*chi;
 198         ic = -sr*shi;
 199         d = rc*rc + ic*ic;
 200         r.real = (rs*rc+is*ic)/d;
 201         r.imag = (is*rc-rs*ic)/d;
 202         return r;
 203 }
 204
 205 static Py_complex c_tanh(x)
 206         Py_complex x;
 207 {
 208         Py_complex r;
 209         double si,ci,shr,chr;
 210         double rs,is,rc,ic;
 211         double d;
 212         si = sin(x.imag);
 213         ci = cos(x.imag);
 214         shr = sinh(x.real);
 215         chr = cosh(x.real);
 216         rs = ci*shr;
 217         is = si*chr;
 218         rc = ci*chr;
 219         ic = si*shr;
 220         d = rc*rc + ic*ic;
 221         r.real = (rs*rc+is*ic)/d;
 222         r.imag = (is*rc-rs*ic)/d;
 223         return r;
 224 }
 225
 226
 227 /* And now the glue to make them available from Python: */
 228
 229 static PyObject *
 230 math_error()
 231 {
 232         if (errno == EDOM)
 233                 PyErr_SetString(PyExc_ValueError, "math domain error");
 234         else if (errno == ERANGE)
 235                 PyErr_SetString(PyExc_OverflowError, "math range error");
 236         else    /* Unexpected math error */
 237                 PyErr_SetFromErrno(PyExc_ValueError);
 238         return NULL;
 239 }
 240
 241 static PyObject *
 242 math_1(args, func)
 243         PyObject *args;
 244         Py_complex (*func) Py_FPROTO((Py_complex));
 245 {
 246         Py_complex x;
 247         if (!PyArg_ParseTuple(args, "D", &x))
 248                 return NULL;
 249         errno = 0;
 250         PyFPE_START_PROTECT("complex function", return 0)
 251         x = (*func)(x);
 252         PyFPE_END_PROTECT(x)
 253         CHECK(x.real);
 254         CHECK(x.imag);
 255         if (errno != 0)
 256                 return math_error();
 257         else
 258                 return PyComplex_FromCComplex(x);
 259 }
 260
 261 #define FUNC1(stubname, func) \
 262         static PyObject * stubname(self, args) PyObject *self, *args; { \
 263                 return math_1(args, func); \
 264         }
 265
 266 FUNC1(cmath_acos, c_acos)
 267 FUNC1(cmath_acosh, c_acosh)
 268 FUNC1(cmath_asin, c_asin)
 269 FUNC1(cmath_asinh, c_asinh)
 270 FUNC1(cmath_atan, c_atan)
 271 FUNC1(cmath_atanh, c_atanh)
 272 FUNC1(cmath_cos, c_cos)
 273 FUNC1(cmath_cosh, c_cosh)
 274 FUNC1(cmath_exp, c_exp)
 275 FUNC1(cmath_log, c_log)
 276 FUNC1(cmath_log10, c_log10)
 277 FUNC1(cmath_sin, c_sin)
 278 FUNC1(cmath_sinh, c_sinh)
 279 FUNC1(cmath_sqrt, c_sqrt)
 280 FUNC1(cmath_tan, c_tan)
 281 FUNC1(cmath_tanh, c_tanh)
 282
 283
 284 static PyMethodDef cmath_methods[] = {
 285         {"acos", cmath_acos, 1},
 286         {"acosh", cmath_acosh, 1},
 287         {"asin", cmath_asin, 1},
 288         {"asinh", cmath_asinh, 1},
 289         {"atan", cmath_atan, 1},
 290         {"atanh", cmath_atanh, 1},
 291         {"cos", cmath_cos, 1},
 292         {"cosh", cmath_cosh, 1},
 293         {"exp", cmath_exp, 1},
 294         {"log", cmath_log, 1},
 295         {"log10", cmath_log10, 1},
 296         {"sin", cmath_sin, 1},
 297         {"sinh", cmath_sinh, 1},
 298         {"sqrt", cmath_sqrt, 1},
 299         {"tan", cmath_tan, 1},
 300         {"tanh", cmath_tanh, 1},
 301         {NULL,          NULL}           /* sentinel */
 302 };
 303
 304 void
 305 initcmath()
 306 {
 307         PyObject *m, *d, *v;
 308
 309         m = Py_InitModule("cmath", cmath_methods);
 310         d = PyModule_GetDict(m);
 311         PyDict_SetItemString(d, "pi",
 312                              v = PyFloat_FromDouble(atan(1.0) * 4.0));
 313         Py_DECREF(v);
 314         PyDict_SetItemString(d, "e", v = PyFloat_FromDouble(exp(1.0)));
 315         Py_DECREF(v);
 316 }