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geqo_erx.c File Reference
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Functions

static int gimme_edge (PlannerInfo *root, Gene gene1, Gene gene2, Edge *edge_table)
 
static void remove_gene (PlannerInfo *root, Gene gene, Edge edge, Edge *edge_table)
 
static Gene gimme_gene (PlannerInfo *root, Edge edge, Edge *edge_table)
 
static Gene edge_failure (PlannerInfo *root, Gene *gene, int index, Edge *edge_table, int num_gene)
 
Edgealloc_edge_table (PlannerInfo *root, int num_gene)
 
void free_edge_table (PlannerInfo *root, Edge *edge_table)
 
float gimme_edge_table (PlannerInfo *root, Gene *tour1, Gene *tour2, int num_gene, Edge *edge_table)
 
int gimme_tour (PlannerInfo *root, Edge *edge_table, Gene *new_gene, int num_gene)
 

Function Documentation

Edge* alloc_edge_table ( PlannerInfo root,
int  num_gene 
)

Definition at line 53 of file geqo_erx.c.

References palloc().

Referenced by geqo().

54 {
55  Edge *edge_table;
56 
57  /*
58  * palloc one extra location so that nodes numbered 1..n can be indexed
59  * directly; 0 will not be used
60  */
61 
62  edge_table = (Edge *) palloc((num_gene + 1) * sizeof(Edge));
63 
64  return edge_table;
65 }
struct Edge Edge
void * palloc(Size size)
Definition: mcxt.c:891
static Gene edge_failure ( PlannerInfo root,
Gene gene,
int  index,
Edge edge_table,
int  num_gene 
)
static

Definition at line 372 of file geqo_erx.c.

References elog, ERROR, geqo_randint, i, and LOG.

Referenced by gimme_tour().

373 {
374  int i;
375  Gene fail_gene = gene[index];
376  int remaining_edges = 0;
377  int four_count = 0;
378  int rand_decision;
379 
380 
381  /*
382  * how many edges remain? how many gene with four total (initial) edges
383  * remain?
384  */
385 
386  for (i = 1; i <= num_gene; i++)
387  {
388  if ((edge_table[i].unused_edges != -1) && (i != (int) fail_gene))
389  {
390  remaining_edges++;
391 
392  if (edge_table[i].total_edges == 4)
393  four_count++;
394  }
395  }
396 
397  /*
398  * random decision of the gene with remaining edges and whose total_edges
399  * == 4
400  */
401 
402  if (four_count != 0)
403  {
404 
405  rand_decision = geqo_randint(root, four_count - 1, 0);
406 
407  for (i = 1; i <= num_gene; i++)
408  {
409 
410  if ((Gene) i != fail_gene &&
411  edge_table[i].unused_edges != -1 &&
412  edge_table[i].total_edges == 4)
413  {
414 
415  four_count--;
416 
417  if (rand_decision == four_count)
418  return (Gene) i;
419  }
420  }
421 
422  elog(LOG, "no edge found via random decision and total_edges == 4");
423  }
424  else if (remaining_edges != 0)
425  {
426  /* random decision of the gene with remaining edges */
427  rand_decision = geqo_randint(root, remaining_edges - 1, 0);
428 
429  for (i = 1; i <= num_gene; i++)
430  {
431 
432  if ((Gene) i != fail_gene &&
433  edge_table[i].unused_edges != -1)
434  {
435 
436  remaining_edges--;
437 
438  if (rand_decision == remaining_edges)
439  return i;
440  }
441  }
442 
443  elog(LOG, "no edge found via random decision with remaining edges");
444  }
445 
446  /*
447  * edge table seems to be empty; this happens sometimes on the last point
448  * due to the fact that the first point is removed from the table even
449  * though only one of its edges has been determined
450  */
451 
452  else
453  { /* occurs only at the last point in the tour;
454  * simply look for the point which is not yet
455  * used */
456 
457  for (i = 1; i <= num_gene; i++)
458  if (edge_table[i].unused_edges >= 0)
459  return (Gene) i;
460 
461  elog(LOG, "no edge found via looking for the last ununsed point");
462  }
463 
464 
465  /* ... should never be reached */
466  elog(ERROR, "no edge found");
467  return 0; /* to keep the compiler quiet */
468 }
#define geqo_randint(root, upper, lower)
Definition: geqo_random.h:38
int Gene
Definition: geqo_gene.h:30
#define LOG
Definition: elog.h:26
Definition: type.h:90
#define ERROR
Definition: elog.h:43
int i
#define elog
Definition: elog.h:219
void free_edge_table ( PlannerInfo root,
Edge edge_table 
)

Definition at line 73 of file geqo_erx.c.

References pfree().

Referenced by geqo().

74 {
75  pfree(edge_table);
76 }
void pfree(void *pointer)
Definition: mcxt.c:992
static int gimme_edge ( PlannerInfo root,
Gene  gene1,
Gene  gene2,
Edge edge_table 
)
static

Definition at line 151 of file geqo_erx.c.

References Abs, Edge::edge_list, i, Edge::total_edges, and Edge::unused_edges.

Referenced by gimme_edge_table().

152 {
153  int i;
154  int edges;
155  int city1 = (int) gene1;
156  int city2 = (int) gene2;
157 
158 
159  /* check whether edge city1->city2 already exists */
160  edges = edge_table[city1].total_edges;
161 
162  for (i = 0; i < edges; i++)
163  {
164  if ((Gene) Abs(edge_table[city1].edge_list[i]) == city2)
165  {
166 
167  /* mark shared edges as negative */
168  edge_table[city1].edge_list[i] = 0 - city2;
169 
170  return 0;
171  }
172  }
173 
174  /* add city1->city2; */
175  edge_table[city1].edge_list[edges] = city2;
176 
177  /* increment the number of edges from city1 */
178  edge_table[city1].total_edges++;
179  edge_table[city1].unused_edges++;
180 
181  return 1;
182 }
int Gene
Definition: geqo_gene.h:30
int total_edges
#define Abs(x)
Definition: c.h:807
Gene edge_list[4]
int i
int unused_edges
float gimme_edge_table ( PlannerInfo root,
Gene tour1,
Gene tour2,
int  num_gene,
Edge edge_table 
)

Definition at line 92 of file geqo_erx.c.

References gimme_edge(), i, Edge::total_edges, and Edge::unused_edges.

Referenced by geqo().

94 {
95  int i,
96  index1,
97  index2;
98  int edge_total; /* total number of unique edges in two genes */
99 
100  /* at first clear the edge table's old data */
101  for (i = 1; i <= num_gene; i++)
102  {
103  edge_table[i].total_edges = 0;
104  edge_table[i].unused_edges = 0;
105  }
106 
107  /* fill edge table with new data */
108 
109  edge_total = 0;
110 
111  for (index1 = 0; index1 < num_gene; index1++)
112  {
113  /*
114  * presume the tour is circular, i.e. 1->2, 2->3, 3->1 this operation
115  * maps n back to 1
116  */
117 
118  index2 = (index1 + 1) % num_gene;
119 
120  /*
121  * edges are bidirectional, i.e. 1->2 is same as 2->1 call gimme_edge
122  * twice per edge
123  */
124 
125  edge_total += gimme_edge(root, tour1[index1], tour1[index2], edge_table);
126  gimme_edge(root, tour1[index2], tour1[index1], edge_table);
127 
128  edge_total += gimme_edge(root, tour2[index1], tour2[index2], edge_table);
129  gimme_edge(root, tour2[index2], tour2[index1], edge_table);
130  }
131 
132  /* return average number of edges per index */
133  return ((float) (edge_total * 2) / (float) num_gene);
134 }
int total_edges
static int gimme_edge(PlannerInfo *root, Gene gene1, Gene gene2, Edge *edge_table)
Definition: geqo_erx.c:151
int i
int unused_edges
static Gene gimme_gene ( PlannerInfo root,
Edge  edge,
Edge edge_table 
)
static

Definition at line 281 of file geqo_erx.c.

References Abs, Edge::edge_list, elog, ERROR, geqo_randint, i, and Edge::unused_edges.

Referenced by gimme_tour().

282 {
283  int i;
284  Gene friend;
285  int minimum_edges;
286  int minimum_count = -1;
287  int rand_decision;
288 
289  /*
290  * no point has edges to more than 4 other points thus, this contrived
291  * minimum will be replaced
292  */
293 
294  minimum_edges = 5;
295 
296  /* consider candidate destination points in edge list */
297 
298  for (i = 0; i < edge.unused_edges; i++)
299  {
300  friend = (Gene) edge.edge_list[i];
301 
302  /*
303  * give priority to shared edges that are negative; so return 'em
304  */
305 
306  /*
307  * negative values are caught here so we need not worry about
308  * converting to absolute values
309  */
310  if (friend < 0)
311  return (Gene) Abs(friend);
312 
313 
314  /*
315  * give priority to candidates with fewest remaining unused edges;
316  * find out what the minimum number of unused edges is
317  * (minimum_edges); if there is more than one candidate with the
318  * minimum number of unused edges keep count of this number
319  * (minimum_count);
320  */
321 
322  /*
323  * The test for minimum_count can probably be removed at some point
324  * but comments should probably indicate exactly why it is guaranteed
325  * that the test will always succeed the first time around. If it can
326  * fail then the code is in error
327  */
328 
329 
330  if (edge_table[(int) friend].unused_edges < minimum_edges)
331  {
332  minimum_edges = edge_table[(int) friend].unused_edges;
333  minimum_count = 1;
334  }
335  else if (minimum_count == -1)
336  elog(ERROR, "minimum_count not set");
337  else if (edge_table[(int) friend].unused_edges == minimum_edges)
338  minimum_count++;
339 
340  } /* for (i=0; i<edge.unused_edges; i++) */
341 
342 
343  /* random decision of the possible candidates to use */
344  rand_decision = geqo_randint(root, minimum_count - 1, 0);
345 
346 
347  for (i = 0; i < edge.unused_edges; i++)
348  {
349  friend = (Gene) edge.edge_list[i];
350 
351  /* return the chosen candidate point */
352  if (edge_table[(int) friend].unused_edges == minimum_edges)
353  {
354  minimum_count--;
355 
356  if (minimum_count == rand_decision)
357  return friend;
358  }
359  }
360 
361  /* ... should never be reached */
362  elog(ERROR, "neither shared nor minimum number nor random edge found");
363  return 0; /* to keep the compiler quiet */
364 }
#define geqo_randint(root, upper, lower)
Definition: geqo_random.h:38
int Gene
Definition: geqo_gene.h:30
#define Abs(x)
Definition: c.h:807
#define ERROR
Definition: elog.h:43
Gene edge_list[4]
int i
#define elog
Definition: elog.h:219
int unused_edges
int gimme_tour ( PlannerInfo root,
Edge edge_table,
Gene new_gene,
int  num_gene 
)

Definition at line 193 of file geqo_erx.c.

References edge_failure(), geqo_randint, gimme_gene(), i, and remove_gene().

Referenced by geqo().

194 {
195  int i;
196  int edge_failures = 0;
197 
198  /* choose int between 1 and num_gene */
199  new_gene[0] = (Gene) geqo_randint(root, num_gene, 1);
200 
201  for (i = 1; i < num_gene; i++)
202  {
203  /*
204  * as each point is entered into the tour, remove it from the edge
205  * table
206  */
207 
208  remove_gene(root, new_gene[i - 1], edge_table[(int) new_gene[i - 1]], edge_table);
209 
210  /* find destination for the newly entered point */
211 
212  if (edge_table[new_gene[i - 1]].unused_edges > 0)
213  new_gene[i] = gimme_gene(root, edge_table[(int) new_gene[i - 1]], edge_table);
214 
215  else
216  { /* cope with fault */
217  edge_failures++;
218 
219  new_gene[i] = edge_failure(root, new_gene, i - 1, edge_table, num_gene);
220  }
221 
222  /* mark this node as incorporated */
223  edge_table[(int) new_gene[i - 1]].unused_edges = -1;
224 
225  } /* for (i=1; i<num_gene; i++) */
226 
227  return edge_failures;
228 
229 }
static Gene edge_failure(PlannerInfo *root, Gene *gene, int index, Edge *edge_table, int num_gene)
Definition: geqo_erx.c:372
static Gene gimme_gene(PlannerInfo *root, Edge edge, Edge *edge_table)
Definition: geqo_erx.c:281
#define geqo_randint(root, upper, lower)
Definition: geqo_random.h:38
int Gene
Definition: geqo_gene.h:30
static void remove_gene(PlannerInfo *root, Gene gene, Edge edge, Edge *edge_table)
Definition: geqo_erx.c:239
int i
static void remove_gene ( PlannerInfo root,
Gene  gene,
Edge  edge,
Edge edge_table 
)
static

Definition at line 239 of file geqo_erx.c.

References Abs, Edge::edge_list, i, and Edge::unused_edges.

Referenced by gimme_tour().

240 {
241  int i,
242  j;
243  int possess_edge;
244  int genes_remaining;
245 
246  /*
247  * do for every gene known to have an edge to input gene (i.e. in
248  * edge_list for input edge)
249  */
250 
251  for (i = 0; i < edge.unused_edges; i++)
252  {
253  possess_edge = (int) Abs(edge.edge_list[i]);
254  genes_remaining = edge_table[possess_edge].unused_edges;
255 
256  /* find the input gene in all edge_lists and delete it */
257  for (j = 0; j < genes_remaining; j++)
258  {
259 
260  if ((Gene) Abs(edge_table[possess_edge].edge_list[j]) == gene)
261  {
262 
263  edge_table[possess_edge].unused_edges--;
264 
265  edge_table[possess_edge].edge_list[j] =
266  edge_table[possess_edge].edge_list[genes_remaining - 1];
267 
268  break;
269  }
270  }
271  }
272 }
int Gene
Definition: geqo_gene.h:30
#define Abs(x)
Definition: c.h:807
Gene edge_list[4]
int i
int unused_edges