108 lines
2.7 KiB
C
108 lines
2.7 KiB
C
/*------------------------------------------------------------------------
|
|
*
|
|
* geqo_px.c
|
|
*
|
|
* position crossover [PX] routines;
|
|
* PX operator according to Syswerda
|
|
* (The Genetic Algorithms Handbook, L Davis, ed)
|
|
*
|
|
* src/backend/optimizer/geqo/geqo_px.c
|
|
*
|
|
*-------------------------------------------------------------------------
|
|
*/
|
|
|
|
/* contributed by:
|
|
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
|
|
* Martin Utesch * Institute of Automatic Control *
|
|
= = University of Mining and Technology =
|
|
* utesch@aut.tu-freiberg.de * Freiberg, Germany *
|
|
=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=
|
|
*/
|
|
|
|
/* the px algorithm is adopted from Genitor : */
|
|
/*************************************************************/
|
|
/* */
|
|
/* Copyright (c) 1990 */
|
|
/* Darrell L. Whitley */
|
|
/* Computer Science Department */
|
|
/* Colorado State University */
|
|
/* */
|
|
/* Permission is hereby granted to copy all or any part of */
|
|
/* this program for free distribution. The author's name */
|
|
/* and this copyright notice must be included in any copy. */
|
|
/* */
|
|
/*************************************************************/
|
|
|
|
#include "postgres.h"
|
|
#include "optimizer/geqo_random.h"
|
|
#include "optimizer/geqo_recombination.h"
|
|
|
|
#if defined(PX)
|
|
|
|
/* px
|
|
*
|
|
* position crossover
|
|
*/
|
|
void
|
|
px(PlannerInfo *root, Gene *tour1, Gene *tour2, Gene *offspring, int num_gene,
|
|
City * city_table)
|
|
{
|
|
int num_positions;
|
|
int i,
|
|
pos,
|
|
tour2_index,
|
|
offspring_index;
|
|
|
|
/* initialize city table */
|
|
for (i = 1; i <= num_gene; i++)
|
|
city_table[i].used = 0;
|
|
|
|
/* choose random positions that will be inherited directly from parent */
|
|
num_positions = geqo_randint(root, 2 * num_gene / 3, num_gene / 3);
|
|
|
|
/* choose random position */
|
|
for (i = 0; i < num_positions; i++)
|
|
{
|
|
pos = geqo_randint(root, num_gene - 1, 0);
|
|
|
|
offspring[pos] = tour1[pos]; /* transfer cities to child */
|
|
city_table[(int) tour1[pos]].used = 1; /* mark city used */
|
|
}
|
|
|
|
tour2_index = 0;
|
|
offspring_index = 0;
|
|
|
|
|
|
/* px main part */
|
|
|
|
while (offspring_index < num_gene)
|
|
{
|
|
|
|
/* next position in offspring filled */
|
|
if (!city_table[(int) tour1[offspring_index]].used)
|
|
{
|
|
|
|
/* next city in tour1 not used */
|
|
if (!city_table[(int) tour2[tour2_index]].used)
|
|
{
|
|
|
|
/* inherit from tour1 */
|
|
offspring[offspring_index] = tour2[tour2_index];
|
|
|
|
tour2_index++;
|
|
offspring_index++;
|
|
}
|
|
else
|
|
{ /* next city in tour2 has been used */
|
|
tour2_index++;
|
|
}
|
|
}
|
|
else
|
|
{ /* next position in offspring is filled */
|
|
offspring_index++;
|
|
}
|
|
}
|
|
}
|
|
|
|
#endif /* defined(PX) */
|