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126 lines
3.0 KiB
C
126 lines
3.0 KiB
C
/*------------------------------------------------------------------------
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*
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* geqo_ox2.c
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*
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* order crossover [OX] routines;
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* OX2 operator according to Syswerda
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* (The Genetic Algorithms Handbook, ed L Davis)
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*
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* $Id: geqo_ox2.c,v 1.5 1999/02/13 23:16:10 momjian Exp $
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*
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*-------------------------------------------------------------------------
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*/
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/* contributed by:
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=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
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* Martin Utesch * Institute of Automatic Control *
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= = University of Mining and Technology =
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* utesch@aut.tu-freiberg.de * Freiberg, Germany *
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=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
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*/
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/* the ox algorithm is adopted from Genitor : */
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/*************************************************************/
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/* */
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/* Copyright (c) 1990 */
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/* Darrell L. Whitley */
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/* Computer Science Department */
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/* Colorado State University */
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/* */
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/* Permission is hereby granted to copy all or any part of */
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/* this program for free distribution. The author's name */
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/* and this copyright notice must be included in any copy. */
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/* */
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/*************************************************************/
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#include "postgres.h"
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#include "nodes/pg_list.h"
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#include "nodes/relation.h"
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#include "nodes/primnodes.h"
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#include "utils/palloc.h"
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#include "utils/elog.h"
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#include "optimizer/internal.h"
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#include "optimizer/paths.h"
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#include "optimizer/pathnode.h"
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#include "optimizer/clauses.h"
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#include "optimizer/cost.h"
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#include "optimizer/geqo_gene.h"
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#include "optimizer/geqo.h"
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#include "optimizer/geqo_recombination.h"
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#include "optimizer/geqo_random.h"
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/* ox2
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*
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* position crossover
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*/
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void
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ox2(Gene *tour1, Gene *tour2, Gene *offspring, int num_gene, City *city_table)
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{
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int k,
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j,
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count,
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pos,
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select,
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num_positions;
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/* initialize city table */
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for (k = 1; k <= num_gene; k++)
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{
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city_table[k].used = 0;
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city_table[k - 1].select_list = -1;
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}
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/* determine the number of positions to be inherited from tour1 */
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num_positions = geqo_randint(2 * num_gene / 3, num_gene / 3);
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/* make a list of selected cities */
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for (k = 0; k < num_positions; k++)
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{
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pos = geqo_randint(num_gene - 1, 0);
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city_table[pos].select_list = (int) tour1[pos];
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city_table[(int) tour1[pos]].used = 1; /* mark used */
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}
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count = 0;
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k = 0;
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/* consolidate the select list to adjacent positions */
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while (count < num_positions)
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{
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if (city_table[k].select_list == -1)
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{
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j = k + 1;
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while ((city_table[j].select_list == -1) && (j < num_gene))
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j++;
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city_table[k].select_list = city_table[j].select_list;
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city_table[j].select_list = -1;
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count++;
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}
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else
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count++;
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k++;
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}
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select = 0;
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for (k = 0; k < num_gene; k++)
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{
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if (city_table[(int) tour2[k]].used)
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{
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offspring[k] = (Gene) city_table[select].select_list;
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select++; /* next city in the select list */
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}
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else
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/* city isn't used yet, so inherit from tour2 */
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offspring[k] = tour2[k];
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}
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}
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