# lmathlib.c (5.0.3)

```/*
** \$Id: lmathlib.c,v 1.56 2003/03/11 12:30:37 roberto Exp \$
** Standard mathematical library
** See Copyright Notice in lua.h
*/

#include <stdlib.h>
#include <math.h>

#define lmathlib_c

#include "lua.h"

#include "lauxlib.h"
#include "lualib.h"

#undef PI
#define PI (3.14159265358979323846)

/*
** If you want Lua to operate in degrees (instead of radians),
** define USE_DEGREES
*/
#ifdef USE_DEGREES
#else
#endif

static int math_abs (lua_State *L) {
lua_pushnumber(L, fabs(luaL_checknumber(L, 1)));
return 1;
}

static int math_sin (lua_State *L) {
return 1;
}

static int math_cos (lua_State *L) {
return 1;
}

static int math_tan (lua_State *L) {
return 1;
}

static int math_asin (lua_State *L) {
return 1;
}

static int math_acos (lua_State *L) {
return 1;
}

static int math_atan (lua_State *L) {
return 1;
}

static int math_atan2 (lua_State *L) {
return 1;
}

static int math_ceil (lua_State *L) {
lua_pushnumber(L, ceil(luaL_checknumber(L, 1)));
return 1;
}

static int math_floor (lua_State *L) {
lua_pushnumber(L, floor(luaL_checknumber(L, 1)));
return 1;
}

static int math_mod (lua_State *L) {
lua_pushnumber(L, fmod(luaL_checknumber(L, 1), luaL_checknumber(L, 2)));
return 1;
}

static int math_sqrt (lua_State *L) {
lua_pushnumber(L, sqrt(luaL_checknumber(L, 1)));
return 1;
}

static int math_pow (lua_State *L) {
lua_pushnumber(L, pow(luaL_checknumber(L, 1), luaL_checknumber(L, 2)));
return 1;
}

static int math_log (lua_State *L) {
lua_pushnumber(L, log(luaL_checknumber(L, 1)));
return 1;
}

static int math_log10 (lua_State *L) {
lua_pushnumber(L, log10(luaL_checknumber(L, 1)));
return 1;
}

static int math_exp (lua_State *L) {
lua_pushnumber(L, exp(luaL_checknumber(L, 1)));
return 1;
}

static int math_deg (lua_State *L) {
return 1;
}

static int math_rad (lua_State *L) {
return 1;
}

static int math_frexp (lua_State *L) {
int e;
lua_pushnumber(L, frexp(luaL_checknumber(L, 1), &e));
lua_pushnumber(L, e);
return 2;
}

static int math_ldexp (lua_State *L) {
lua_pushnumber(L, ldexp(luaL_checknumber(L, 1), luaL_checkint(L, 2)));
return 1;
}

static int math_min (lua_State *L) {
int n = lua_gettop(L);  /* number of arguments */
lua_Number dmin = luaL_checknumber(L, 1);
int i;
for (i=2; i<=n; i++) {
lua_Number d = luaL_checknumber(L, i);
if (d < dmin)
dmin = d;
}
lua_pushnumber(L, dmin);
return 1;
}

static int math_max (lua_State *L) {
int n = lua_gettop(L);  /* number of arguments */
lua_Number dmax = luaL_checknumber(L, 1);
int i;
for (i=2; i<=n; i++) {
lua_Number d = luaL_checknumber(L, i);
if (d > dmax)
dmax = d;
}
lua_pushnumber(L, dmax);
return 1;
}

static int math_random (lua_State *L) {
/* the `%' avoids the (rare) case of r==1, and is needed also because on
some systems (SunOS!) `rand()' may return a value larger than RAND_MAX */
lua_Number r = (lua_Number)(rand()%RAND_MAX) / (lua_Number)RAND_MAX;
switch (lua_gettop(L)) {  /* check number of arguments */
case 0: {  /* no arguments */
lua_pushnumber(L, r);  /* Number between 0 and 1 */
break;
}
case 1: {  /* only upper limit */
int u = luaL_checkint(L, 1);
luaL_argcheck(L, 1<=u, 1, "interval is empty");
lua_pushnumber(L, (int)floor(r*u)+1);  /* int between 1 and `u' */
break;
}
case 2: {  /* lower and upper limits */
int l = luaL_checkint(L, 1);
int u = luaL_checkint(L, 2);
luaL_argcheck(L, l<=u, 2, "interval is empty");
lua_pushnumber(L, (int)floor(r*(u-l+1))+l);  /* int between `l' and `u' */
break;
}
default: return luaL_error(L, "wrong number of arguments");
}
return 1;
}

static int math_randomseed (lua_State *L) {
srand(luaL_checkint(L, 1));
return 0;
}

static const luaL_reg mathlib[] = {
{"abs",   math_abs},
{"sin",   math_sin},
{"cos",   math_cos},
{"tan",   math_tan},
{"asin",  math_asin},
{"acos",  math_acos},
{"atan",  math_atan},
{"atan2", math_atan2},
{"ceil",  math_ceil},
{"floor", math_floor},
{"mod",   math_mod},
{"frexp", math_frexp},
{"ldexp", math_ldexp},
{"sqrt",  math_sqrt},
{"min",   math_min},
{"max",   math_max},
{"log",   math_log},
{"log10", math_log10},
{"exp",   math_exp},
{"deg",   math_deg},
{"pow",   math_pow},
{"random",     math_random},
{"randomseed", math_randomseed},
{NULL, NULL}
};

/*
** Open math library
*/
LUALIB_API int luaopen_math (lua_State *L) {
luaL_openlib(L, LUA_MATHLIBNAME, mathlib, 0);
lua_pushliteral(L, "pi");
lua_pushnumber(L, PI);
lua_settable(L, -3);
lua_pushliteral(L, "__pow");
lua_pushcfunction(L, math_pow);
lua_settable(L, LUA_GLOBALSINDEX);
return 1;
}

```