src/lib/lmathlib.c

   1 /*
   2 ** $Id: lmathlib.c,v 1.32 2000/10/31 13:10:24 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 #include "lua.h"
  12
  13 #include "lauxlib.h"
  14 #include "lualib.h"
  15
  16
  17 #undef PI
  18 #define PI (3.14159265358979323846)
  19 #define RADIANS_PER_DEGREE (PI/180.0)
  20
  21
  22
  23 /*
  24 ** If you want Lua to operate in radians (instead of degrees),
  25 ** define RADIANS
  26 */
  27 #ifdef RADIANS
  28 #define FROMRAD(a)      (a)
  29 #define TORAD(a)        (a)
  30 #else
  31 #define FROMRAD(a)      ((a)/RADIANS_PER_DEGREE)
  32 #define TORAD(a)        ((a)*RADIANS_PER_DEGREE)
  33 #endif
  34
  35
  36 static int math_abs (lua_State *L) {
  37   lua_pushnumber(L, fabs(luaL_check_number(L, 1)));
  38   return 1;
  39 }
  40
  41 static int math_sin (lua_State *L) {
  42   lua_pushnumber(L, sin(TORAD(luaL_check_number(L, 1))));
  43   return 1;
  44 }
  45
  46 static int math_cos (lua_State *L) {
  47   lua_pushnumber(L, cos(TORAD(luaL_check_number(L, 1))));
  48   return 1;
  49 }
  50
  51 static int math_tan (lua_State *L) {
  52   lua_pushnumber(L, tan(TORAD(luaL_check_number(L, 1))));
  53   return 1;
  54 }
  55
  56 static int math_asin (lua_State *L) {
  57   lua_pushnumber(L, FROMRAD(asin(luaL_check_number(L, 1))));
  58   return 1;
  59 }
  60
  61 static int math_acos (lua_State *L) {
  62   lua_pushnumber(L, FROMRAD(acos(luaL_check_number(L, 1))));
  63   return 1;
  64 }
  65
  66 static int math_atan (lua_State *L) {
  67   lua_pushnumber(L, FROMRAD(atan(luaL_check_number(L, 1))));
  68   return 1;
  69 }
  70
  71 static int math_atan2 (lua_State *L) {
  72   lua_pushnumber(L, FROMRAD(atan2(luaL_check_number(L, 1), luaL_check_number(L, 2))));
  73   return 1;
  74 }
  75
  76 static int math_ceil (lua_State *L) {
  77   lua_pushnumber(L, ceil(luaL_check_number(L, 1)));
  78   return 1;
  79 }
  80
  81 static int math_floor (lua_State *L) {
  82   lua_pushnumber(L, floor(luaL_check_number(L, 1)));
  83   return 1;
  84 }
  85
  86 static int math_mod (lua_State *L) {
  87   lua_pushnumber(L, fmod(luaL_check_number(L, 1), luaL_check_number(L, 2)));
  88   return 1;
  89 }
  90
  91 static int math_sqrt (lua_State *L) {
  92   lua_pushnumber(L, sqrt(luaL_check_number(L, 1)));
  93   return 1;
  94 }
  95
  96 static int math_pow (lua_State *L) {
  97   lua_pushnumber(L, pow(luaL_check_number(L, 1), luaL_check_number(L, 2)));
  98   return 1;
  99 }
 100
 101 static int math_log (lua_State *L) {
 102   lua_pushnumber(L, log(luaL_check_number(L, 1)));
 103   return 1;
 104 }
 105
 106 static int math_log10 (lua_State *L) {
 107   lua_pushnumber(L, log10(luaL_check_number(L, 1)));
 108   return 1;
 109 }
 110
 111 static int math_exp (lua_State *L) {
 112   lua_pushnumber(L, exp(luaL_check_number(L, 1)));
 113   return 1;
 114 }
 115
 116 static int math_deg (lua_State *L) {
 117   lua_pushnumber(L, luaL_check_number(L, 1)/RADIANS_PER_DEGREE);
 118   return 1;
 119 }
 120
 121 static int math_rad (lua_State *L) {
 122   lua_pushnumber(L, luaL_check_number(L, 1)*RADIANS_PER_DEGREE);
 123   return 1;
 124 }
 125
 126 static int math_frexp (lua_State *L) {
 127   int e;
 128   lua_pushnumber(L, frexp(luaL_check_number(L, 1), &e));
 129   lua_pushnumber(L, e);
 130   return 2;
 131 }
 132
 133 static int math_ldexp (lua_State *L) {
 134   lua_pushnumber(L, ldexp(luaL_check_number(L, 1), luaL_check_int(L, 2)));
 135   return 1;
 136 }
 137
 138
 139
 140 static int math_min (lua_State *L) {
 141   int n = lua_gettop(L);  /* number of arguments */
 142   double dmin = luaL_check_number(L, 1);
 143   int i;
 144   for (i=2; i<=n; i++) {
 145     double d = luaL_check_number(L, i);
 146     if (d < dmin)
 147       dmin = d;
 148   }
 149   lua_pushnumber(L, dmin);
 150   return 1;
 151 }
 152
 153
 154 static int math_max (lua_State *L) {
 155   int n = lua_gettop(L);  /* number of arguments */
 156   double dmax = luaL_check_number(L, 1);
 157   int i;
 158   for (i=2; i<=n; i++) {
 159     double d = luaL_check_number(L, i);
 160     if (d > dmax)
 161       dmax = d;
 162   }
 163   lua_pushnumber(L, dmax);
 164   return 1;
 165 }
 166
 167
 168 static int math_random (lua_State *L) {
 169   /* the '%' avoids the (rare) case of r==1, and is needed also because on
 170      some systems (SunOS!) "rand()" may return a value larger than RAND_MAX */
 171   double r = (double)(rand()%RAND_MAX) / (double)RAND_MAX;
 172   switch (lua_gettop(L)) {  /* check number of arguments */
 173     case 0: {  /* no arguments */
 174       lua_pushnumber(L, r);  /* Number between 0 and 1 */
 175       break;
 176     }
 177     case 1: {  /* only upper limit */
 178       int u = luaL_check_int(L, 1);
 179       luaL_arg_check(L, 1<=u, 1, "interval is empty");
 180       lua_pushnumber(L, (int)(r*u)+1);  /* integer between 1 and `u' */
 181       break;
 182     }
 183     case 2: {  /* lower and upper limits */
 184       int l = luaL_check_int(L, 1);
 185       int u = luaL_check_int(L, 2);
 186       luaL_arg_check(L, l<=u, 2, "interval is empty");
 187       lua_pushnumber(L, (int)(r*(u-l+1))+l);  /* integer between `l' and `u' */
 188       break;
 189     }
 190     default: lua_error(L, "wrong number of arguments");
 191   }
 192   return 1;
 193 }
 194
 195
 196 static int math_randomseed (lua_State *L) {
 197   srand(luaL_check_int(L, 1));
 198   return 0;
 199 }
 200
 201
 202 static const struct luaL_reg mathlib[] = {
 203 {"abs",   math_abs},
 204 {"sin",   math_sin},
 205 {"cos",   math_cos},
 206 {"tan",   math_tan},
 207 {"asin",  math_asin},
 208 {"acos",  math_acos},
 209 {"atan",  math_atan},
 210 {"atan2", math_atan2},
 211 {"ceil",  math_ceil},
 212 {"floor", math_floor},
 213 {"mod",   math_mod},
 214 {"frexp", math_frexp},
 215 {"ldexp", math_ldexp},
 216 {"sqrt",  math_sqrt},
 217 {"min",   math_min},
 218 {"max",   math_max},
 219 {"log",   math_log},
 220 {"log10", math_log10},
 221 {"exp",   math_exp},
 222 {"deg",   math_deg},
 223 {"rad",   math_rad},
 224 {"random",     math_random},
 225 {"randomseed", math_randomseed}
 226 };
 227
 228 /*
 229 ** Open math library
 230 */
 231 LUALIB_API void lua_mathlibopen (lua_State *L) {
 232   luaL_openl(L, mathlib);
 233   lua_pushcfunction(L, math_pow);
 234   lua_settagmethod(L, LUA_TNUMBER, "pow");
 235   lua_pushnumber(L, PI);
 236   lua_setglobal(L, "PI");
 237 }
 238