liblua/lmathlib.c

   1 /*
   2 ** $Id: lmathlib.c,v 1.83 2013/03/07 18:21:32 roberto Exp $
   3 ** Standard mathematical library
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7
   8 #include <stdlib.h>
   9 #include <math.h>
  10
  11 #define lmathlib_c
  12 #define LUA_LIB
  13
  14 #include "lua.h"
  15
  16 #include "lauxlib.h"
  17 #include "lualib.h"
  18
  19
  20 #undef PI
  21 #define PI      ((lua_Number)(3.1415926535897932384626433832795))
  22 #define RADIANS_PER_DEGREE      ((lua_Number)(PI/180.0))
  23
  24
  25
  26 static int math_abs (lua_State *L) {
  27   lua_pushnumber(L, l_mathop(fabs)(luaL_checknumber(L, 1)));
  28   return 1;
  29 }
  30
  31 static int math_sin (lua_State *L) {
  32   lua_pushnumber(L, l_mathop(sin)(luaL_checknumber(L, 1)));
  33   return 1;
  34 }
  35
  36 static int math_sinh (lua_State *L) {
  37   lua_pushnumber(L, l_mathop(sinh)(luaL_checknumber(L, 1)));
  38   return 1;
  39 }
  40
  41 static int math_cos (lua_State *L) {
  42   lua_pushnumber(L, l_mathop(cos)(luaL_checknumber(L, 1)));
  43   return 1;
  44 }
  45
  46 static int math_cosh (lua_State *L) {
  47   lua_pushnumber(L, l_mathop(cosh)(luaL_checknumber(L, 1)));
  48   return 1;
  49 }
  50
  51 static int math_tan (lua_State *L) {
  52   lua_pushnumber(L, l_mathop(tan)(luaL_checknumber(L, 1)));
  53   return 1;
  54 }
  55
  56 static int math_tanh (lua_State *L) {
  57   lua_pushnumber(L, l_mathop(tanh)(luaL_checknumber(L, 1)));
  58   return 1;
  59 }
  60
  61 static int math_asin (lua_State *L) {
  62   lua_pushnumber(L, l_mathop(asin)(luaL_checknumber(L, 1)));
  63   return 1;
  64 }
  65
  66 static int math_acos (lua_State *L) {
  67   lua_pushnumber(L, l_mathop(acos)(luaL_checknumber(L, 1)));
  68   return 1;
  69 }
  70
  71 static int math_atan (lua_State *L) {
  72   lua_pushnumber(L, l_mathop(atan)(luaL_checknumber(L, 1)));
  73   return 1;
  74 }
  75
  76 static int math_atan2 (lua_State *L) {
  77   lua_pushnumber(L, l_mathop(atan2)(luaL_checknumber(L, 1),
  78                                 luaL_checknumber(L, 2)));
  79   return 1;
  80 }
  81
  82 static int math_ceil (lua_State *L) {
  83   lua_pushnumber(L, l_mathop(ceil)(luaL_checknumber(L, 1)));
  84   return 1;
  85 }
  86
  87 static int math_floor (lua_State *L) {
  88   lua_pushnumber(L, l_mathop(floor)(luaL_checknumber(L, 1)));
  89   return 1;
  90 }
  91
  92 static int math_fmod (lua_State *L) {
  93   lua_pushnumber(L, l_mathop(fmod)(luaL_checknumber(L, 1),
  94                                luaL_checknumber(L, 2)));
  95   return 1;
  96 }
  97
  98 static int math_modf (lua_State *L) {
  99   lua_Number ip;
 100   lua_Number fp = l_mathop(modf)(luaL_checknumber(L, 1), &ip);
 101   lua_pushnumber(L, ip);
 102   lua_pushnumber(L, fp);
 103   return 2;
 104 }
 105
 106 static int math_sqrt (lua_State *L) {
 107   lua_pushnumber(L, l_mathop(sqrt)(luaL_checknumber(L, 1)));
 108   return 1;
 109 }
 110
 111 static int math_pow (lua_State *L) {
 112   lua_Number x = luaL_checknumber(L, 1);
 113   lua_Number y = luaL_checknumber(L, 2);
 114   lua_pushnumber(L, l_mathop(pow)(x, y));
 115   return 1;
 116 }
 117
 118 static int math_log (lua_State *L) {
 119   lua_Number x = luaL_checknumber(L, 1);
 120   lua_Number res;
 121   if (lua_isnoneornil(L, 2))
 122     res = l_mathop(log)(x);
 123   else {
 124     lua_Number base = luaL_checknumber(L, 2);
 125     if (base == (lua_Number)10.0) res = l_mathop(log10)(x);
 126     else res = l_mathop(log)(x)/l_mathop(log)(base);
 127   }
 128   lua_pushnumber(L, res);
 129   return 1;
 130 }
 131
 132 #if defined(LUA_COMPAT_LOG10)
 133 static int math_log10 (lua_State *L) {
 134   lua_pushnumber(L, l_mathop(log10)(luaL_checknumber(L, 1)));
 135   return 1;
 136 }
 137 #endif
 138
 139 static int math_exp (lua_State *L) {
 140   lua_pushnumber(L, l_mathop(exp)(luaL_checknumber(L, 1)));
 141   return 1;
 142 }
 143
 144 static int math_deg (lua_State *L) {
 145   lua_pushnumber(L, luaL_checknumber(L, 1)/RADIANS_PER_DEGREE);
 146   return 1;
 147 }
 148
 149 static int math_rad (lua_State *L) {
 150   lua_pushnumber(L, luaL_checknumber(L, 1)*RADIANS_PER_DEGREE);
 151   return 1;
 152 }
 153
 154 static int math_frexp (lua_State *L) {
 155   int e;
 156   lua_pushnumber(L, l_mathop(frexp)(luaL_checknumber(L, 1), &e));
 157   lua_pushinteger(L, e);
 158   return 2;
 159 }
 160
 161 static int math_ldexp (lua_State *L) {
 162   lua_Number x = luaL_checknumber(L, 1);
 163   int ep = luaL_checkint(L, 2);
 164   lua_pushnumber(L, l_mathop(ldexp)(x, ep));
 165   return 1;
 166 }
 167
 168
 169
 170 static int math_min (lua_State *L) {
 171   int n = lua_gettop(L);  /* number of arguments */
 172   lua_Number dmin = luaL_checknumber(L, 1);
 173   int i;
 174   for (i=2; i<=n; i++) {
 175     lua_Number d = luaL_checknumber(L, i);
 176     if (d < dmin)
 177       dmin = d;
 178   }
 179   lua_pushnumber(L, dmin);
 180   return 1;
 181 }
 182
 183
 184 static int math_max (lua_State *L) {
 185   int n = lua_gettop(L);  /* number of arguments */
 186   lua_Number dmax = luaL_checknumber(L, 1);
 187   int i;
 188   for (i=2; i<=n; i++) {
 189     lua_Number d = luaL_checknumber(L, i);
 190     if (d > dmax)
 191       dmax = d;
 192   }
 193   lua_pushnumber(L, dmax);
 194   return 1;
 195 }
 196
 197
 198 static int math_random (lua_State *L) {
 199   /* the `%' avoids the (rare) case of r==1, and is needed also because on
 200      some systems (SunOS!) `rand()' may return a value larger than RAND_MAX */
 201   lua_Number r = (lua_Number)(rand()%RAND_MAX) / (lua_Number)RAND_MAX;
 202   switch (lua_gettop(L)) {  /* check number of arguments */
 203     case 0: {  /* no arguments */
 204       lua_pushnumber(L, r);  /* Number between 0 and 1 */
 205       break;
 206     }
 207     case 1: {  /* only upper limit */
 208       lua_Number u = luaL_checknumber(L, 1);
 209       luaL_argcheck(L, (lua_Number)1.0 <= u, 1, "interval is empty");
 210       lua_pushnumber(L, l_mathop(floor)(r*u) + (lua_Number)(1.0));  /* [1, u] */
 211       break;
 212     }
 213     case 2: {  /* lower and upper limits */
 214       lua_Number l = luaL_checknumber(L, 1);
 215       lua_Number u = luaL_checknumber(L, 2);
 216       luaL_argcheck(L, l <= u, 2, "interval is empty");
 217       lua_pushnumber(L, l_mathop(floor)(r*(u-l+1)) + l);  /* [l, u] */
 218       break;
 219     }
 220     default: return luaL_error(L, "wrong number of arguments");
 221   }
 222   return 1;
 223 }
 224
 225
 226 static int math_randomseed (lua_State *L) {
 227   srand(luaL_checkunsigned(L, 1));
 228   (void)rand(); /* discard first value to avoid undesirable correlations */
 229   return 0;
 230 }
 231
 232
 233 static const luaL_Reg mathlib[] = {
 234   {"abs",   math_abs},
 235   {"acos",  math_acos},
 236   {"asin",  math_asin},
 237   {"atan2", math_atan2},
 238   {"atan",  math_atan},
 239   {"ceil",  math_ceil},
 240   {"cosh",   math_cosh},
 241   {"cos",   math_cos},
 242   {"deg",   math_deg},
 243   {"exp",   math_exp},
 244   {"floor", math_floor},
 245   {"fmod",   math_fmod},
 246   {"frexp", math_frexp},
 247   {"ldexp", math_ldexp},
 248 #if defined(LUA_COMPAT_LOG10)
 249   {"log10", math_log10},
 250 #endif
 251   {"log",   math_log},
 252   {"max",   math_max},
 253   {"min",   math_min},
 254   {"modf",   math_modf},
 255   {"pow",   math_pow},
 256   {"rad",   math_rad},
 257   {"random",     math_random},
 258   {"randomseed", math_randomseed},
 259   {"sinh",   math_sinh},
 260   {"sin",   math_sin},
 261   {"sqrt",  math_sqrt},
 262   {"tanh",   math_tanh},
 263   {"tan",   math_tan},
 264   {NULL, NULL}
 265 };
 266
 267
 268 /*
 269 ** Open math library
 270 */
 271 LUAMOD_API int luaopen_math (lua_State *L) {
 272   luaL_newlib(L, mathlib);
 273   lua_pushnumber(L, PI);
 274   lua_setfield(L, -2, "pi");
 275   lua_pushnumber(L, HUGE_VAL);
 276   lua_setfield(L, -2, "huge");
 277   return 1;
 278 }
 279