root / trunk / extensions / extGraph / src / org / gvsig / graph / solvers / TspSolverAnnealing.java @ 39203
History | View | Annotate | Download (11 KB)
| 1 |
package org.gvsig.graph.solvers; |
|---|---|
| 2 |
|
| 3 |
import java.util.Random; |
| 4 |
|
| 5 |
import org.gvsig.graph.core.GvFlag; |
| 6 |
|
| 7 |
public class TspSolverAnnealing { |
| 8 |
static int T_INIT = 100; |
| 9 |
static double FINAL_T = 0.1; |
| 10 |
static double COOLING = 0.9; /* to lower down T (< 1) */ |
| 11 |
|
| 12 |
|
| 13 |
int n;
|
| 14 |
int[] iorder; |
| 15 |
int[] jorder; |
| 16 |
float[] b = new float[4]; |
| 17 |
double[][] odMatrix; |
| 18 |
boolean bReturnToOrigin;
|
| 19 |
int origenTSP, destinoTSP;
|
| 20 |
int[] vTSP; |
| 21 |
|
| 22 |
|
| 23 |
|
| 24 |
/*
|
| 25 |
* State vars
|
| 26 |
*/
|
| 27 |
int verbose = 0; |
| 28 |
private GvFlag[] flags = null; |
| 29 |
private boolean bVolverOrigen = false; |
| 30 |
private double distTotMin = Double.MAX_VALUE; |
| 31 |
|
| 32 |
/* float calcula_dist_ordenacion(int v[], int bVolverOrigen)
|
| 33 |
{
|
| 34 |
float dist, distTot;
|
| 35 |
int i;
|
| 36 |
|
| 37 |
distTot = odMatrix[origenTSP][v[0]]; // Origen al primer punto
|
| 38 |
for (i = 0; i< numElemTSP-1;i++)
|
| 39 |
{
|
| 40 |
dist = odMatrix[v[i]][v[i+1]];
|
| 41 |
distTot = distTot + dist;
|
| 42 |
}
|
| 43 |
|
| 44 |
// desde y hasta el almacen (distancia al primero y al ?ltimo
|
| 45 |
if (bVolverOrigen)
|
| 46 |
{
|
| 47 |
dist = odMatrix[v[numElemTSP-1]][origenTSP];
|
| 48 |
distTot = distTot + dist;
|
| 49 |
}
|
| 50 |
else
|
| 51 |
{
|
| 52 |
dist = odMatrix[v[numElemTSP-1]][destinoTSP];
|
| 53 |
distTot = distTot + dist;
|
| 54 |
}
|
| 55 |
return distTot;
|
| 56 |
} */
|
| 57 |
|
| 58 |
|
| 59 |
double pathLength()
|
| 60 |
{
|
| 61 |
int i;
|
| 62 |
double len = 0; |
| 63 |
|
| 64 |
len = D(origenTSP, iorder[0]);
|
| 65 |
for (i = 0; i < n-1; i++) |
| 66 |
{
|
| 67 |
len += D(iorder[i], iorder[i+1]);
|
| 68 |
} |
| 69 |
|
| 70 |
if (bReturnToOrigin)
|
| 71 |
len += D(iorder[n-1], origenTSP); /* close path */ |
| 72 |
else
|
| 73 |
len += D(iorder[n-1], destinoTSP); /* close path */ |
| 74 |
return (len);
|
| 75 |
} |
| 76 |
|
| 77 |
|
| 78 |
int mod(int a, int b) { |
| 79 |
int aux = (a % b);
|
| 80 |
if (aux < 0) |
| 81 |
aux = aux + b; |
| 82 |
return aux;
|
| 83 |
} |
| 84 |
|
| 85 |
double D(int f, int t) { |
| 86 |
return odMatrix[f][t];
|
| 87 |
} |
| 88 |
|
| 89 |
|
| 90 |
/*
|
| 91 |
* Local Search Heuristics
|
| 92 |
* b-------a b a
|
| 93 |
* . . => .\ /.
|
| 94 |
* . d...e . . e...d .
|
| 95 |
* ./ \. . .
|
| 96 |
* c f c-------f
|
| 97 |
*/
|
| 98 |
double getThreeWayCost (int[] p) |
| 99 |
{
|
| 100 |
int a, b, c, d, e, f;
|
| 101 |
a = iorder[mod(p[0]-1, n)]; b = iorder[p[0]]; |
| 102 |
c = iorder[p[1]]; d = iorder[mod(p[1]+1,n)]; |
| 103 |
e = iorder[p[2]]; f = iorder[mod(p[2]+1,n)]; |
| 104 |
|
| 105 |
// b va a ser el nuevo origen => sumamos su distancia a nuestro origen fijo
|
| 106 |
double Dant, Dnuevo, Ddiff = 0; |
| 107 |
Dant = D(origenTSP, iorder[0]);
|
| 108 |
Dnuevo = D(origenTSP, b); |
| 109 |
Ddiff = Dnuevo - Dant; |
| 110 |
|
| 111 |
// tambi?n hay que mirar la distancia al destino desde el ?ltimo punto
|
| 112 |
int fin=n-1; |
| 113 |
if (bReturnToOrigin)
|
| 114 |
{
|
| 115 |
// p[2] va a ser el pr?ximo ?ltimo punto
|
| 116 |
Dant = D(iorder[fin], origenTSP); |
| 117 |
Dnuevo = D(iorder[p[2]], origenTSP);
|
| 118 |
Ddiff = Ddiff + Dnuevo - Dant; |
| 119 |
} |
| 120 |
else
|
| 121 |
{
|
| 122 |
Dant = D(iorder[fin], destinoTSP); |
| 123 |
Dnuevo = D(iorder[p[2]], destinoTSP);
|
| 124 |
Ddiff = Ddiff + Dnuevo - Dant; |
| 125 |
} |
| 126 |
|
| 127 |
|
| 128 |
return (D(a,d) + D(e,b) + D(c,f) - D(a,b) - D(c,d) - D(e,f) + Ddiff);
|
| 129 |
/* add cost between d and e if non symetric TSP */
|
| 130 |
|
| 131 |
// A?ADIR DIFERENCIA DE COSTE A LOS NODOS INMOVILES. (ORIGEN Y ?DESTINO?)
|
| 132 |
} |
| 133 |
|
| 134 |
void doThreeWay (int[] p) |
| 135 |
{
|
| 136 |
int i, count, m1, m2, m3, a, b, c, d, e, f;
|
| 137 |
int index;
|
| 138 |
a = mod(p[0]-1,n); b = p[0]; |
| 139 |
c = p[1]; d = mod(p[1]+1,n); |
| 140 |
e = p[2]; f = mod(p[2]+1,n); |
| 141 |
|
| 142 |
m1 = mod(n+c-b,n)+1; /* num cities from b to c */ |
| 143 |
m2 = mod(n+a-f,n)+1; /* num cities from f to a */ |
| 144 |
m3 = mod(n+e-d,n)+1; /* num cities from d to e */ |
| 145 |
|
| 146 |
count = 0;
|
| 147 |
/* [b..c] */
|
| 148 |
for (i = 0; i < m1; i++) |
| 149 |
{
|
| 150 |
index = mod(i+b,n); |
| 151 |
jorder[count++] = iorder[index]; |
| 152 |
} |
| 153 |
|
| 154 |
/* [f..a] */
|
| 155 |
for (i = 0; i < m2; i++) |
| 156 |
{
|
| 157 |
index = mod(i+f,n); |
| 158 |
jorder[count++] = iorder[index]; |
| 159 |
} |
| 160 |
|
| 161 |
/* [d..e] */
|
| 162 |
for (i = 0; i < m3; i++) |
| 163 |
{
|
| 164 |
index = mod(i+d,n); |
| 165 |
jorder[count++] = iorder[index]; |
| 166 |
} |
| 167 |
|
| 168 |
/* copy segment back into iorder */
|
| 169 |
for (i = 0; i < n; i++) iorder[i] = jorder[i]; |
| 170 |
} |
| 171 |
|
| 172 |
/*
|
| 173 |
* c..b c..b
|
| 174 |
* \/ => | |
|
| 175 |
* /\ | |
|
| 176 |
* a d a d
|
| 177 |
*/
|
| 178 |
double getReverseCost (int[] p) |
| 179 |
{
|
| 180 |
int a, b, c, d;
|
| 181 |
a = iorder[mod(p[0]-1,n)]; b = iorder[p[0]]; |
| 182 |
c = iorder[p[1]]; d = iorder[mod(p[1]+1,n)]; |
| 183 |
|
| 184 |
double Dant = 0, Dnuevo = 0, Ddiff = 0; |
| 185 |
|
| 186 |
if (p[0]==0 || p[1]==0) |
| 187 |
{
|
| 188 |
Dant = D(origenTSP,iorder[0]);
|
| 189 |
if (p[0]==0) |
| 190 |
Dnuevo = D(origenTSP, c); |
| 191 |
else
|
| 192 |
Dnuevo = D(origenTSP, b); |
| 193 |
Ddiff = Dnuevo-Dant; |
| 194 |
} |
| 195 |
int fin = n-1; |
| 196 |
if (bReturnToOrigin) // Miramos la distancia al cero |
| 197 |
{
|
| 198 |
// iorder[p[1]] o iorder[p[0]] va a acabar en la ?ltima posici?n
|
| 199 |
if (p[0]==fin || p[1] == fin) // tambi?n hay que mirar la distancia al destino desde el ?ltimo punto |
| 200 |
{
|
| 201 |
Dant = D(iorder[fin], origenTSP); |
| 202 |
if (p[0]==fin) |
| 203 |
Dnuevo = D(c,origenTSP); |
| 204 |
else
|
| 205 |
Dnuevo = D(b, origenTSP); |
| 206 |
Ddiff = Ddiff + Dnuevo - Dant; |
| 207 |
|
| 208 |
} |
| 209 |
} |
| 210 |
else
|
| 211 |
{
|
| 212 |
if (p[0]==fin || p[1] == fin) // tambi?n hay que mirar la distancia al destino desde el ?ltimo punto |
| 213 |
{
|
| 214 |
Dant = D(iorder[fin], destinoTSP); |
| 215 |
if (p[0]==fin) |
| 216 |
Dnuevo = D(c,destinoTSP); |
| 217 |
else
|
| 218 |
Dnuevo = D(b, destinoTSP); |
| 219 |
Ddiff = Ddiff + Dnuevo - Dant; |
| 220 |
|
| 221 |
} |
| 222 |
} |
| 223 |
|
| 224 |
return (D(d,b) + D(c,a) - D(a,b) - D(c,d) + Ddiff);
|
| 225 |
/* add cost between c and b if non symetric TSP */
|
| 226 |
// A?ADIR DIFERENCIA DE COSTE A LOS NODOS INMOVILES. (ORIGEN Y ?DESTINO?)
|
| 227 |
} |
| 228 |
|
| 229 |
void doReverse(int[] p) |
| 230 |
{
|
| 231 |
int i, nswaps, first, last, tmp;
|
| 232 |
|
| 233 |
/* reverse path b...c */
|
| 234 |
nswaps = (mod(p[1]-p[0],n)+1)/2; |
| 235 |
for (i = 0; i < nswaps; i++) |
| 236 |
{
|
| 237 |
first = mod(p[0]+i, n);
|
| 238 |
last = mod(p[1]-i, n);
|
| 239 |
tmp = iorder[first]; |
| 240 |
|
| 241 |
iorder[first] = iorder[last]; |
| 242 |
iorder[last] = tmp; |
| 243 |
} |
| 244 |
} |
| 245 |
|
| 246 |
double annealing()
|
| 247 |
{
|
| 248 |
int[] p = new int[3]; |
| 249 |
int i=1, j, pathchg; |
| 250 |
int numOnPath, numNotOnPath;
|
| 251 |
double pathlen, bestlen;
|
| 252 |
double energyChange, T;
|
| 253 |
|
| 254 |
/*
|
| 255 |
* Set up first eulerian path iorder to be improved by
|
| 256 |
* simulated annealing.
|
| 257 |
*/
|
| 258 |
/* bool conEulerian = true;
|
| 259 |
if (conEulerian)
|
| 260 |
findEulerianPath(); */
|
| 261 |
|
| 262 |
|
| 263 |
pathlen = pathLength(); // (iorder);
|
| 264 |
bestlen = pathlen; |
| 265 |
Random rnd = new Random(); |
| 266 |
|
| 267 |
int TRIES_PER_T = 500*n; |
| 268 |
int IMPROVED_PATH_PER_T = 60*n; |
| 269 |
|
| 270 |
for (T = T_INIT; T > FINAL_T; T *= COOLING) /* annealing schedule */ |
| 271 |
{
|
| 272 |
pathchg = 0;
|
| 273 |
for (j = 0; j < TRIES_PER_T; j++) |
| 274 |
{
|
| 275 |
do {
|
| 276 |
p[0] = rnd.nextInt(n);
|
| 277 |
p[1] = rnd.nextInt(n);
|
| 278 |
if (p[0] == p[1]) |
| 279 |
p[1] = mod(p[0]+1,n); /* non-empty path */ |
| 280 |
numOnPath = mod(p[1]-p[0],n) + 1; |
| 281 |
numNotOnPath = n - numOnPath; |
| 282 |
} while (numOnPath < 2 || numNotOnPath < 2) ; /* non-empty path */ |
| 283 |
|
| 284 |
double rreal = rnd.nextDouble();
|
| 285 |
if ((rnd.nextInt() % 2) == 0) /* threeWay */ |
| 286 |
{
|
| 287 |
do {
|
| 288 |
p[2] = mod(rnd.nextInt(numNotOnPath)+p[1]+1,n); |
| 289 |
} while (p[0] == mod(p[2]+1,n)); /* avoids a non-change */ |
| 290 |
|
| 291 |
energyChange = getThreeWayCost (p); |
| 292 |
if ((energyChange < 0) || (rreal < Math.exp(-energyChange/T))) |
| 293 |
{
|
| 294 |
pathchg++; |
| 295 |
pathlen += energyChange; |
| 296 |
doThreeWay (p); |
| 297 |
} |
| 298 |
} |
| 299 |
else /* path Reverse */ |
| 300 |
{
|
| 301 |
energyChange = getReverseCost (p); |
| 302 |
if ((energyChange < 0) || (rreal < Math.exp(-energyChange/T))) |
| 303 |
{
|
| 304 |
pathchg++; |
| 305 |
pathlen += energyChange; |
| 306 |
doReverse(p); |
| 307 |
} |
| 308 |
} |
| 309 |
if (pathlen < bestlen)
|
| 310 |
{
|
| 311 |
pathlen = pathLength(); // Calculamos la distancia de verdad, por si no interesa
|
| 312 |
// hacer el cambio. pathlen es en realidad una estimaci?n
|
| 313 |
if (pathlen < bestlen)
|
| 314 |
{
|
| 315 |
bestlen = pathlen; |
| 316 |
for (i=0; i< n; i++) |
| 317 |
vTSP[i+1] = iorder[i];
|
| 318 |
} |
| 319 |
} |
| 320 |
if (pathchg > IMPROVED_PATH_PER_T) break; /* finish early */ |
| 321 |
} |
| 322 |
if (pathchg == 0) break; /* if no change then quit */ |
| 323 |
} |
| 324 |
return bestlen;
|
| 325 |
} |
| 326 |
|
| 327 |
|
| 328 |
public void setStops(GvFlag[] flags) { |
| 329 |
this.flags = flags;
|
| 330 |
} |
| 331 |
|
| 332 |
|
| 333 |
/**
|
| 334 |
* This function will use annealing only if numStops >= 6. If numStops < 6, it will
|
| 335 |
* use direct calculation, ensuring the optimum result.
|
| 336 |
* @return
|
| 337 |
*/
|
| 338 |
public GvFlag[] calculate() { |
| 339 |
GvFlag[] orderedStops = new GvFlag[flags.length]; |
| 340 |
int numStops = flags.length;
|
| 341 |
int numElemTSP;
|
| 342 |
origenTSP = 0;
|
| 343 |
destinoTSP = numStops-1;
|
| 344 |
if (bVolverOrigen )
|
| 345 |
numElemTSP = numStops-1;
|
| 346 |
else
|
| 347 |
numElemTSP = numStops-2;
|
| 348 |
|
| 349 |
n = numElemTSP; |
| 350 |
|
| 351 |
bReturnToOrigin = bVolverOrigen; |
| 352 |
|
| 353 |
iorder = new int[n]; |
| 354 |
jorder = new int[n]; |
| 355 |
|
| 356 |
|
| 357 |
|
| 358 |
vTSP = new int[numStops]; |
| 359 |
vTSP[0] = origenTSP;
|
| 360 |
vTSP[numStops-1] = destinoTSP;
|
| 361 |
if (numElemTSP > 0) |
| 362 |
{
|
| 363 |
// v = new int[numElemTSP];
|
| 364 |
for (int i=0; i< numElemTSP; i++) |
| 365 |
{
|
| 366 |
iorder[i] = i + 1;
|
| 367 |
vTSP[i+1] = i + 1; // v[i]; |
| 368 |
} |
| 369 |
|
| 370 |
} |
| 371 |
|
| 372 |
/* identity permutation */
|
| 373 |
// for (i = 0; i < n; i++) iorder[i] = i+1;
|
| 374 |
|
| 375 |
double distTotal=0.0; |
| 376 |
|
| 377 |
if (numElemTSP < 7) |
| 378 |
{
|
| 379 |
|
| 380 |
distTotMin = calculate_distance(iorder,bVolverOrigen); |
| 381 |
|
| 382 |
permut(iorder, numElemTSP, bVolverOrigen); |
| 383 |
|
| 384 |
distTotal = distTotMin ; |
| 385 |
} |
| 386 |
else
|
| 387 |
{
|
| 388 |
distTotal = annealing(); |
| 389 |
} |
| 390 |
|
| 391 |
System.out.println("DistTotal = " + distTotal); |
| 392 |
System.out.print("new order = ["); |
| 393 |
for (int i=0; i < vTSP.length; i++) { |
| 394 |
orderedStops[i] = flags[vTSP[i]]; |
| 395 |
System.out.print(vTSP[i] + " "); |
| 396 |
} |
| 397 |
System.out.println("]"); |
| 398 |
return orderedStops;
|
| 399 |
} |
| 400 |
|
| 401 |
|
| 402 |
double calculate_distance(int v[], boolean bVolverOrigen) |
| 403 |
{
|
| 404 |
double dist, distTot;
|
| 405 |
int i;
|
| 406 |
|
| 407 |
distTot = D(origenTSP, v[0]); // Origen al primer punto |
| 408 |
for (i = 0; i< n-1;i++) |
| 409 |
{
|
| 410 |
//frmDocMap.Distancia v(i), v(i + 1), dist, tiempo
|
| 411 |
dist = D(v[i], v[i+1]);
|
| 412 |
distTot = distTot + dist; |
| 413 |
} |
| 414 |
|
| 415 |
// desde y hasta el almacen (distancia al primero y al ?ltimo
|
| 416 |
if (bVolverOrigen)
|
| 417 |
{
|
| 418 |
dist = D(v[n-1], origenTSP);
|
| 419 |
distTot = distTot + dist; |
| 420 |
} |
| 421 |
else
|
| 422 |
{
|
| 423 |
dist = D(v[n-1], destinoTSP);
|
| 424 |
distTot = distTot + dist; |
| 425 |
} |
| 426 |
return distTot;
|
| 427 |
} |
| 428 |
|
| 429 |
void exchange(int v[], int p1, int p2) |
| 430 |
{
|
| 431 |
int aux;
|
| 432 |
aux = v[p1]; |
| 433 |
v[p1] = v[p2]; |
| 434 |
v[p2] = aux; |
| 435 |
} |
| 436 |
|
| 437 |
void permut (int v[], int m, boolean bVolverOrigen) |
| 438 |
{
|
| 439 |
int i, j;
|
| 440 |
double distTot;
|
| 441 |
|
| 442 |
if (m > 0) |
| 443 |
for (i = 0; i < m; i++) |
| 444 |
{
|
| 445 |
exchange(v, i, m-1);
|
| 446 |
permut (v, m-1, bVolverOrigen);
|
| 447 |
exchange(v, i, m-1);
|
| 448 |
} |
| 449 |
else
|
| 450 |
{
|
| 451 |
// escribir_vector (v);
|
| 452 |
// Aqu? tenemos el vector que buscamos
|
| 453 |
// Calculamos su distancia y si es menor que la que tenemos guardada, guardamos el nuevo vector.
|
| 454 |
distTot = calculate_distance(v, bVolverOrigen); |
| 455 |
|
| 456 |
if (distTot < distTotMin)
|
| 457 |
{
|
| 458 |
distTotMin = distTot; |
| 459 |
for (j = 0; j< n; j++) |
| 460 |
vTSP[j+1] = v[j];
|
| 461 |
} |
| 462 |
// 'MuestraVector v
|
| 463 |
|
| 464 |
} |
| 465 |
} |
| 466 |
|
| 467 |
|
| 468 |
public void setODMatrix(double[][] odMatrix) { |
| 469 |
this.odMatrix = odMatrix;
|
| 470 |
} |
| 471 |
|
| 472 |
|
| 473 |
/**
|
| 474 |
* @return true if the path is closed => will return to origin.
|
| 475 |
* @see setReturnToOrigin
|
| 476 |
*/
|
| 477 |
public boolean isClosed() { |
| 478 |
return bReturnToOrigin;
|
| 479 |
} |
| 480 |
|
| 481 |
|
| 482 |
public void setReturnToOrigin(boolean returnToOrigin) { |
| 483 |
bReturnToOrigin = returnToOrigin; |
| 484 |
} |
| 485 |
|
| 486 |
} |