lua/src/mf.c

   1 /***
   2  membership function
   3  @module liba.mf
   4 */
   5
   6 #include "a.h"
   7 #include "a/mf.h"
   8
   9 /***
  10  gaussian membership function
  11  @tparam number x input value for which to compute membership value.
  12  @tparam number sigma is the standard deviation.
  13  @tparam number c is the mean.
  14  @treturn number membership value.
  15  @function gauss
  16 */
  17 static int liba_mf_gauss_(lua_State *L, int arg)
  18 {
  19     a_float const x = (a_float)luaL_checknumber(L, arg + 1);
  20     a_float const sigma = (a_float)luaL_checknumber(L, arg + 2);
  21     a_float const c = (a_float)luaL_checknumber(L, arg + 3);
  22     lua_pushnumber(L, (lua_Number)a_mf_gauss(x, sigma, c));
  23     return 1;
  24 }
  25 static int liba_mf_gauss(lua_State *L)
  26 {
  27     return liba_mf_gauss_(L, 0);
  28 }
  29
  30 /***
  31  product of two sigmoidal membership functions
  32  @tparam number x input value for which to compute membership value.
  33  @tparam number sigma1 is the standard deviation of the left gaussian function.
  34  @tparam number c1 is the mean of the left gaussian function.
  35  @tparam number sigma2 is the standard deviation of the right gaussian function.
  36  @tparam number c2 is the mean of the right gaussian function.
  37  @treturn number membership value.
  38  @function gauss2
  39 */
  40 static int liba_mf_gauss2_(lua_State *L, int arg)
  41 {
  42     a_float const x = (a_float)luaL_checknumber(L, arg + 1);
  43     a_float const sigma1 = (a_float)luaL_checknumber(L, arg + 2);
  44     a_float const c1 = (a_float)luaL_checknumber(L, arg + 3);
  45     a_float const sigma2 = (a_float)luaL_checknumber(L, arg + 4);
  46     a_float const c2 = (a_float)luaL_checknumber(L, arg + 4);
  47     lua_pushnumber(L, (lua_Number)a_mf_gauss2(x, sigma1, c1, sigma2, c2));
  48     return 1;
  49 }
  50 static int liba_mf_gauss2(lua_State *L)
  51 {
  52     return liba_mf_gauss2_(L, 0);
  53 }
  54
  55 /***
  56  generalized bell-shaped membership function
  57  @tparam number x input value for which to compute membership value.
  58  @tparam number a defines the width of the membership function, where a larger value creates a wider membership function.
  59  @tparam number b defines the shape of the curve on either side of the central plateau, where a larger value creates a more steep transition.
  60  @tparam number c defines the center of the membership function.
  61  @treturn number membership value.
  62  @function gbell
  63 */
  64 static int liba_mf_gbell_(lua_State *L, int arg)
  65 {
  66     a_float const x = (a_float)luaL_checknumber(L, arg + 1);
  67     a_float const a = (a_float)luaL_checknumber(L, arg + 2);
  68     a_float const b = (a_float)luaL_checknumber(L, arg + 3);
  69     a_float const c = (a_float)luaL_checknumber(L, arg + 4);
  70     lua_pushnumber(L, (lua_Number)a_mf_gbell(x, a, b, c));
  71     return 1;
  72 }
  73 static int liba_mf_gbell(lua_State *L)
  74 {
  75     return liba_mf_gbell_(L, 0);
  76 }
  77
  78 /***
  79  sigmoidal membership function
  80  @tparam number x input value for which to compute membership value.
  81  @tparam number a defines the width of the transition area.
  82  @tparam number c defines the center of the transition area.
  83  @treturn number membership value.
  84  @function sig
  85 */
  86 static int liba_mf_sig_(lua_State *L, int arg)
  87 {
  88     a_float const x = (a_float)luaL_checknumber(L, arg + 1);
  89     a_float const a = (a_float)luaL_checknumber(L, arg + 2);
  90     a_float const c = (a_float)luaL_checknumber(L, arg + 3);
  91     lua_pushnumber(L, (lua_Number)a_mf_sig(x, a, c));
  92     return 1;
  93 }
  94 static int liba_mf_sig(lua_State *L)
  95 {
  96     return liba_mf_sig_(L, 0);
  97 }
  98
  99 /***
 100  difference between two sigmoidal membership functions
 101  @tparam number x input value for which to compute membership value.
 102  @tparam number a1 defines the width of the first transition area.
 103  @tparam number c1 defines the center of the first transition area.
 104  @tparam number a2 defines the width of the second transition area.
 105  @tparam number c2 defines the center of the second transition area.
 106  @treturn number membership value.
 107  @function dsig
 108 */
 109 static int liba_mf_dsig_(lua_State *L, int arg)
 110 {
 111     a_float const x = (a_float)luaL_checknumber(L, arg + 1);
 112     a_float const a1 = (a_float)luaL_checknumber(L, arg + 2);
 113     a_float const c1 = (a_float)luaL_checknumber(L, arg + 3);
 114     a_float const a2 = (a_float)luaL_checknumber(L, arg + 4);
 115     a_float const c2 = (a_float)luaL_checknumber(L, arg + 4);
 116     lua_pushnumber(L, (lua_Number)a_mf_dsig(x, a1, c1, a2, c2));
 117     return 1;
 118 }
 119 static int liba_mf_dsig(lua_State *L)
 120 {
 121     return liba_mf_dsig_(L, 0);
 122 }
 123
 124 /***
 125  product of two sigmoidal membership functions
 126  @tparam number x input value for which to compute membership value.
 127  @tparam number a1 defines the width of the first transition area.
 128  @tparam number c1 defines the center of the first transition area.
 129  @tparam number a2 defines the width of the second transition area.
 130  @tparam number c2 defines the center of the second transition area.
 131  @treturn number membership value.
 132  @function psig
 133 */
 134 static int liba_mf_psig_(lua_State *L, int arg)
 135 {
 136     a_float const x = (a_float)luaL_checknumber(L, arg + 1);
 137     a_float const a1 = (a_float)luaL_checknumber(L, arg + 2);
 138     a_float const c1 = (a_float)luaL_checknumber(L, arg + 3);
 139     a_float const a2 = (a_float)luaL_checknumber(L, arg + 4);
 140     a_float const c2 = (a_float)luaL_checknumber(L, arg + 4);
 141     lua_pushnumber(L, (lua_Number)a_mf_psig(x, a1, c1, a2, c2));
 142     return 1;
 143 }
 144 static int liba_mf_psig(lua_State *L)
 145 {
 146     return liba_mf_psig_(L, 0);
 147 }
 148
 149 /***
 150  trapezoidal membership function
 151  @tparam number x input value for which to compute membership value.
 152  @tparam number a defines its left foot.
 153  @tparam number b defines its left shoulder.
 154  @tparam number c defines its right shoulder.
 155  @tparam number d defines its right foot.
 156  @treturn number membership value.
 157  @function trap
 158 */
 159 static int liba_mf_trap_(lua_State *L, int arg)
 160 {
 161     a_float const x = (a_float)luaL_checknumber(L, arg + 1);
 162     a_float const a = (a_float)luaL_checknumber(L, arg + 2);
 163     a_float const b = (a_float)luaL_checknumber(L, arg + 3);
 164     a_float const c = (a_float)luaL_checknumber(L, arg + 4);
 165     a_float const d = (a_float)luaL_checknumber(L, arg + 4);
 166     lua_pushnumber(L, (lua_Number)a_mf_trap(x, a, b, c, d));
 167     return 1;
 168 }
 169 static int liba_mf_trap(lua_State *L)
 170 {
 171     return liba_mf_trap_(L, 0);
 172 }
 173
 174 /***
 175  triangular membership function
 176  @tparam number x input value for which to compute membership value.
 177  @tparam number a defines its left foot.
 178  @tparam number b defines its peak.
 179  @tparam number c defines its right foot.
 180  @treturn number membership value.
 181  @function tri
 182 */
 183 static int liba_mf_tri_(lua_State *L, int arg)
 184 {
 185     a_float const x = (a_float)luaL_checknumber(L, arg + 1);
 186     a_float const a = (a_float)luaL_checknumber(L, arg + 2);
 187     a_float const b = (a_float)luaL_checknumber(L, arg + 3);
 188     a_float const c = (a_float)luaL_checknumber(L, arg + 4);
 189     lua_pushnumber(L, (lua_Number)a_mf_tri(x, a, b, c));
 190     return 1;
 191 }
 192 static int liba_mf_tri(lua_State *L)
 193 {
 194     return liba_mf_tri_(L, 0);
 195 }
 196
 197 /***
 198  linear s-shaped saturation membership function
 199  @tparam number x input value for which to compute membership value.
 200  @tparam number a defines its foot.
 201  @tparam number b defines its shoulder.
 202  @treturn number membership value.
 203  @function lins
 204 */
 205 static int liba_mf_lins_(lua_State *L, int arg)
 206 {
 207     a_float const x = (a_float)luaL_checknumber(L, arg + 1);
 208     a_float const a = (a_float)luaL_checknumber(L, arg + 2);
 209     a_float const b = (a_float)luaL_checknumber(L, arg + 3);
 210     lua_pushnumber(L, (lua_Number)a_mf_lins(x, a, b));
 211     return 1;
 212 }
 213 static int liba_mf_lins(lua_State *L)
 214 {
 215     return liba_mf_lins_(L, 0);
 216 }
 217
 218 /***
 219  linear z-shaped saturation membership function
 220  @tparam number x input value for which to compute membership value.
 221  @tparam number a defines its shoulder.
 222  @tparam number b defines its foot.
 223  @treturn number membership value.
 224  @function linz
 225 */
 226 static int liba_mf_linz_(lua_State *L, int arg)
 227 {
 228     a_float const x = (a_float)luaL_checknumber(L, arg + 1);
 229     a_float const a = (a_float)luaL_checknumber(L, arg + 2);
 230     a_float const b = (a_float)luaL_checknumber(L, arg + 3);
 231     lua_pushnumber(L, (lua_Number)a_mf_linz(x, a, b));
 232     return 1;
 233 }
 234 static int liba_mf_linz(lua_State *L)
 235 {
 236     return liba_mf_linz_(L, 0);
 237 }
 238
 239 /***
 240  s-shaped membership function
 241  @tparam number x input value for which to compute membership value.
 242  @tparam number a defines its foot.
 243  @tparam number b defines its shoulder.
 244  @treturn number membership value.
 245  @function s
 246 */
 247 static int liba_mf_s_(lua_State *L, int arg)
 248 {
 249     a_float const x = (a_float)luaL_checknumber(L, arg + 1);
 250     a_float const a = (a_float)luaL_checknumber(L, arg + 2);
 251     a_float const b = (a_float)luaL_checknumber(L, arg + 3);
 252     lua_pushnumber(L, (lua_Number)a_mf_s(x, a, b));
 253     return 1;
 254 }
 255 static int liba_mf_s(lua_State *L)
 256 {
 257     return liba_mf_s_(L, 0);
 258 }
 259
 260 /***
 261  z-shaped membership function
 262  @tparam number x input value for which to compute membership value.
 263  @tparam number a defines its shoulder.
 264  @tparam number b defines its foot.
 265  @treturn number membership value.
 266  @function z
 267 */
 268 static int liba_mf_z_(lua_State *L, int arg)
 269 {
 270     a_float const x = (a_float)luaL_checknumber(L, arg + 1);
 271     a_float const a = (a_float)luaL_checknumber(L, arg + 2);
 272     a_float const b = (a_float)luaL_checknumber(L, arg + 3);
 273     lua_pushnumber(L, (lua_Number)a_mf_z(x, a, b));
 274     return 1;
 275 }
 276 static int liba_mf_z(lua_State *L)
 277 {
 278     return liba_mf_z_(L, 0);
 279 }
 280
 281 /***
 282  z-shaped membership function
 283  @tparam number x input value for which to compute membership value.
 284  @tparam number a defines its left foot.
 285  @tparam number b defines its left shoulder.
 286  @tparam number c defines its right shoulder.
 287  @tparam number d defines its right foot.
 288  @treturn number membership value.
 289  @function pi
 290 */
 291 static int liba_mf_pi_(lua_State *L, int arg)
 292 {
 293     a_float const x = (a_float)luaL_checknumber(L, arg + 1);
 294     a_float const a = (a_float)luaL_checknumber(L, arg + 2);
 295     a_float const b = (a_float)luaL_checknumber(L, arg + 3);
 296     a_float const c = (a_float)luaL_checknumber(L, arg + 4);
 297     a_float const d = (a_float)luaL_checknumber(L, arg + 4);
 298     lua_pushnumber(L, (lua_Number)a_mf_pi(x, a, b, c, d));
 299     return 1;
 300 }
 301 static int liba_mf_pi(lua_State *L)
 302 {
 303     return liba_mf_pi_(L, 0);
 304 }
 305
 306 /***
 307  membership function
 308  @tparam int e type for membership function
 309  @tparam number x input value for which to compute membership value.
 310  @tparam number ... is an array that stores parameters.
 311  @treturn number membership value.
 312  @function mf
 313 */
 314 static int liba_mf_mf(lua_State *L)
 315 {
 316     lua_Integer const e = luaL_checkinteger(L, 1);
 317     switch (e)
 318     {
 319     case A_MF_PI:
 320         return liba_mf_pi_(L, 1);
 321     case A_MF_Z:
 322         return liba_mf_z_(L, 1);
 323     case A_MF_S:
 324         return liba_mf_s_(L, 1);
 325     case A_MF_LINZ:
 326         return liba_mf_linz_(L, 1);
 327     case A_MF_LINS:
 328         return liba_mf_lins_(L, 1);
 329     case A_MF_TRI:
 330         return liba_mf_tri_(L, 1);
 331     case A_MF_TRAP:
 332         return liba_mf_trap_(L, 1);
 333     case A_MF_PSIG:
 334         return liba_mf_psig_(L, 1);
 335     case A_MF_DSIG:
 336         return liba_mf_dsig_(L, 1);
 337     case A_MF_SIG:
 338         return liba_mf_sig_(L, 1);
 339     case A_MF_GBELL:
 340         return liba_mf_gbell_(L, 1);
 341     case A_MF_GAUSS2:
 342         return liba_mf_gauss2_(L, 1);
 343     case A_MF_GAUSS:
 344         return liba_mf_gauss_(L, 1);
 345     case A_MF_NUL:
 346     default:
 347         return 0;
 348     }
 349 }
 350
 351 static int liba_mf_(lua_State *L)
 352 {
 353     lua_pushcfunction(L, liba_mf_mf);
 354     lua_replace(L, 1);
 355     lua_call(L, lua_gettop(L) - 1, 1);
 356     return 1;
 357 }
 358
 359 int luaopen_liba_mf(lua_State *L)
 360 {
 361     /***
 362      enumeration for membership function
 363      @field NUL none
 364      @field GAUSS gaussian membership function
 365      @field GAUSS2 gaussian combination membership function
 366      @field GBELL generalized bell-shaped membership function
 367      @field SIG sigmoidal membership function
 368      @field DSIG difference between two sigmoidal membership functions
 369      @field PSIG product of two sigmoidal membership functions
 370      @field TRAP trapezoidal membership function
 371      @field TRI triangular membership function
 372      @field LINS linear s-shaped saturation membership function
 373      @field LINZ linear z-shaped saturation membership function
 374      @field S s-shaped membership function
 375      @field Z z-shaped membership function
 376      @field PI pi-shaped membership function
 377      @table mf
 378     */
 379     static lua_int const enums[] = {
 380         {"NUL", A_MF_NUL},
 381         {"GAUSS", A_MF_GAUSS},
 382         {"GAUSS2", A_MF_GAUSS2},
 383         {"GBELL", A_MF_GBELL},
 384         {"SIG", A_MF_SIG},
 385         {"DSIG", A_MF_DSIG},
 386         {"PSIG", A_MF_PSIG},
 387         {"TRAP", A_MF_TRAP},
 388         {"TRI", A_MF_TRI},
 389         {"LINS", A_MF_LINS},
 390         {"LINZ", A_MF_LINZ},
 391         {"S", A_MF_S},
 392         {"Z", A_MF_Z},
 393         {"PI", A_MF_PI},
 394     };
 395     static lua_fun const funcs[] = {
 396         {"gauss", liba_mf_gauss},
 397         {"gauss2", liba_mf_gauss2},
 398         {"gbell", liba_mf_gbell},
 399         {"sig", liba_mf_sig},
 400         {"dsig", liba_mf_dsig},
 401         {"psig", liba_mf_psig},
 402         {"trap", liba_mf_trap},
 403         {"tri", liba_mf_tri},
 404         {"lins", liba_mf_lins},
 405         {"linz", liba_mf_linz},
 406         {"s", liba_mf_s},
 407         {"z", liba_mf_z},
 408         {"pi", liba_mf_pi},
 409         {"mf", liba_mf_mf},
 410     };
 411     lua_createtable(L, 0, A_LEN(enums) + A_LEN(funcs));
 412     lua_int_reg(L, -1, enums, A_LEN(enums));
 413     lua_fun_reg(L, -1, funcs, A_LEN(funcs));
 414     lua_createtable(L, 0, 1);
 415     lua_fun_set(L, -1, "__call", liba_mf_);
 416     lua_setmetatable(L, -2);
 417     return 1;
 418 }