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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

◆ alloc_edge_table()

Edge* alloc_edge_table ( PlannerInfo root,
int  num_gene 
)

Definition at line 56 of file geqo_erx.c.

57 {
58  Edge *edge_table;
59 
60  /*
61  * palloc one extra location so that nodes numbered 1..n can be indexed
62  * directly; 0 will not be used
63  */
64 
65  edge_table = (Edge *) palloc((num_gene + 1) * sizeof(Edge));
66 
67  return edge_table;
68 }
struct Edge Edge
void * palloc(Size size)
Definition: mcxt.c:1316

References palloc().

Referenced by geqo().

◆ edge_failure()

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.

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 unused 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 LOG
Definition: elog.h:31
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:224
int Gene
Definition: geqo_gene.h:30
int geqo_randint(PlannerInfo *root, int upper, int lower)
Definition: geqo_random.c:36
int i
Definition: isn.c:73
tree ctl root
Definition: radixtree.h:1880
Definition: type.h:95

References elog, ERROR, geqo_randint(), i, LOG, and root.

Referenced by gimme_tour().

◆ free_edge_table()

void free_edge_table ( PlannerInfo root,
Edge edge_table 
)

Definition at line 76 of file geqo_erx.c.

77 {
78  pfree(edge_table);
79 }
void pfree(void *pointer)
Definition: mcxt.c:1520

References pfree().

Referenced by geqo().

◆ gimme_edge()

static int gimme_edge ( PlannerInfo root,
Gene  gene1,
Gene  gene2,
Edge edge_table 
)
static

Definition at line 154 of file geqo_erx.c.

155 {
156  int i;
157  int edges;
158  int city1 = (int) gene1;
159  int city2 = (int) gene2;
160 
161 
162  /* check whether edge city1->city2 already exists */
163  edges = edge_table[city1].total_edges;
164 
165  for (i = 0; i < edges; i++)
166  {
167  if ((Gene) abs(edge_table[city1].edge_list[i]) == city2)
168  {
169 
170  /* mark shared edges as negative */
171  edge_table[city1].edge_list[i] = 0 - city2;
172 
173  return 0;
174  }
175  }
176 
177  /* add city1->city2; */
178  edge_table[city1].edge_list[edges] = city2;
179 
180  /* increment the number of edges from city1 */
181  edge_table[city1].total_edges++;
182  edge_table[city1].unused_edges++;
183 
184  return 1;
185 }
int unused_edges
Gene edge_list[4]
int total_edges

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

Referenced by gimme_edge_table().

◆ gimme_edge_table()

float gimme_edge_table ( PlannerInfo root,
Gene tour1,
Gene tour2,
int  num_gene,
Edge edge_table 
)

Definition at line 95 of file geqo_erx.c.

97 {
98  int i,
99  index1,
100  index2;
101  int edge_total; /* total number of unique edges in two genes */
102 
103  /* at first clear the edge table's old data */
104  for (i = 1; i <= num_gene; i++)
105  {
106  edge_table[i].total_edges = 0;
107  edge_table[i].unused_edges = 0;
108  }
109 
110  /* fill edge table with new data */
111 
112  edge_total = 0;
113 
114  for (index1 = 0; index1 < num_gene; index1++)
115  {
116  /*
117  * presume the tour is circular, i.e. 1->2, 2->3, 3->1 this operation
118  * maps n back to 1
119  */
120 
121  index2 = (index1 + 1) % num_gene;
122 
123  /*
124  * edges are bidirectional, i.e. 1->2 is same as 2->1 call gimme_edge
125  * twice per edge
126  */
127 
128  edge_total += gimme_edge(root, tour1[index1], tour1[index2], edge_table);
129  gimme_edge(root, tour1[index2], tour1[index1], edge_table);
130 
131  edge_total += gimme_edge(root, tour2[index1], tour2[index2], edge_table);
132  gimme_edge(root, tour2[index2], tour2[index1], edge_table);
133  }
134 
135  /* return average number of edges per index */
136  return ((float) (edge_total * 2) / (float) num_gene);
137 }
static int gimme_edge(PlannerInfo *root, Gene gene1, Gene gene2, Edge *edge_table)
Definition: geqo_erx.c:154

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

Referenced by geqo().

◆ gimme_gene()

static Gene gimme_gene ( PlannerInfo root,
Edge  edge,
Edge edge_table 
)
static

Definition at line 282 of file geqo_erx.c.

283 {
284  int i;
285  Gene friend;
286  int minimum_edges;
287  int minimum_count = -1;
288  int rand_decision;
289 
290  /*
291  * no point has edges to more than 4 other points thus, this contrived
292  * minimum will be replaced
293  */
294 
295  minimum_edges = 5;
296 
297  /* consider candidate destination points in edge list */
298 
299  for (i = 0; i < edge.unused_edges; i++)
300  {
301  friend = (Gene) edge.edge_list[i];
302 
303  /*
304  * give priority to shared edges that are negative; so return 'em
305  */
306 
307  /*
308  * negative values are caught here so we need not worry about
309  * converting to absolute values
310  */
311  if (friend < 0)
312  return (Gene) abs(friend);
313 
314 
315  /*
316  * give priority to candidates with fewest remaining unused edges;
317  * find out what the minimum number of unused edges is
318  * (minimum_edges); if there is more than one candidate with the
319  * minimum number of unused edges keep count of this number
320  * (minimum_count);
321  */
322 
323  /*
324  * The test for minimum_count can probably be removed at some point
325  * but comments should probably indicate exactly why it is guaranteed
326  * that the test will always succeed the first time around. If it can
327  * fail then the code is in error
328  */
329 
330 
331  if (edge_table[(int) friend].unused_edges < minimum_edges)
332  {
333  minimum_edges = edge_table[(int) friend].unused_edges;
334  minimum_count = 1;
335  }
336  else if (minimum_count == -1)
337  elog(ERROR, "minimum_count not set");
338  else if (edge_table[(int) friend].unused_edges == minimum_edges)
339  minimum_count++;
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 }
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:77

References Edge::edge_list, elog, ERROR, geqo_randint(), i, if(), root, and Edge::unused_edges.

Referenced by gimme_tour().

◆ gimme_tour()

int gimme_tour ( PlannerInfo root,
Edge edge_table,
Gene new_gene,
int  num_gene 
)

Definition at line 196 of file geqo_erx.c.

197 {
198  int i;
199  int edge_failures = 0;
200 
201  /* choose int between 1 and num_gene */
202  new_gene[0] = (Gene) geqo_randint(root, num_gene, 1);
203 
204  for (i = 1; i < num_gene; i++)
205  {
206  /*
207  * as each point is entered into the tour, remove it from the edge
208  * table
209  */
210 
211  remove_gene(root, new_gene[i - 1], edge_table[(int) new_gene[i - 1]], edge_table);
212 
213  /* find destination for the newly entered point */
214 
215  if (edge_table[new_gene[i - 1]].unused_edges > 0)
216  new_gene[i] = gimme_gene(root, edge_table[(int) new_gene[i - 1]], edge_table);
217 
218  else
219  { /* cope with fault */
220  edge_failures++;
221 
222  new_gene[i] = edge_failure(root, new_gene, i - 1, edge_table, num_gene);
223  }
224 
225  /* mark this node as incorporated */
226  edge_table[(int) new_gene[i - 1]].unused_edges = -1;
227  } /* for (i=1; i<num_gene; i++) */
228 
229  return edge_failures;
230 }
static Gene gimme_gene(PlannerInfo *root, Edge edge, Edge *edge_table)
Definition: geqo_erx.c:282
static Gene edge_failure(PlannerInfo *root, Gene *gene, int index, Edge *edge_table, int num_gene)
Definition: geqo_erx.c:372
static void remove_gene(PlannerInfo *root, Gene gene, Edge edge, Edge *edge_table)
Definition: geqo_erx.c:240

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

Referenced by geqo().

◆ remove_gene()

static void remove_gene ( PlannerInfo root,
Gene  gene,
Edge  edge,
Edge edge_table 
)
static

Definition at line 240 of file geqo_erx.c.

241 {
242  int i,
243  j;
244  int possess_edge;
245  int genes_remaining;
246 
247  /*
248  * do for every gene known to have an edge to input gene (i.e. in
249  * edge_list for input edge)
250  */
251 
252  for (i = 0; i < edge.unused_edges; i++)
253  {
254  possess_edge = abs(edge.edge_list[i]);
255  genes_remaining = edge_table[possess_edge].unused_edges;
256 
257  /* find the input gene in all edge_lists and delete it */
258  for (j = 0; j < genes_remaining; j++)
259  {
260 
261  if ((Gene) abs(edge_table[possess_edge].edge_list[j]) == gene)
262  {
263 
264  edge_table[possess_edge].unused_edges--;
265 
266  edge_table[possess_edge].edge_list[j] =
267  edge_table[possess_edge].edge_list[genes_remaining - 1];
268 
269  break;
270  }
271  }
272  }
273 }
int j
Definition: isn.c:74

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

Referenced by gimme_tour().