diff options
Diffstat (limited to 'src/backend/optimizer/geqo/geqo_mutation.c')
-rw-r--r-- | src/backend/optimizer/geqo/geqo_mutation.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/src/backend/optimizer/geqo/geqo_mutation.c b/src/backend/optimizer/geqo/geqo_mutation.c new file mode 100644 index 0000000..2af0295 --- /dev/null +++ b/src/backend/optimizer/geqo/geqo_mutation.c @@ -0,0 +1,66 @@ +/*------------------------------------------------------------------------ +* +* geqo_mutation.c +* +* TSP mutation routines +* +* src/backend/optimizer/geqo/geqo_mutation.c +* +*------------------------------------------------------------------------- +*/ + +/* contributed by: + =*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*= + * Martin Utesch * Institute of Automatic Control * + = = University of Mining and Technology = + * utesch@aut.tu-freiberg.de * Freiberg, Germany * + =*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*= + */ + +/* this 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_mutation.h" +#include "optimizer/geqo_random.h" + +#if defined(CX) /* currently used only in CX mode */ + +void +geqo_mutation(PlannerInfo *root, Gene *tour, int num_gene) +{ + int swap1; + int swap2; + int num_swaps = geqo_randint(root, num_gene / 3, 0); + Gene temp; + + + while (num_swaps > 0) + { + swap1 = geqo_randint(root, num_gene - 1, 0); + swap2 = geqo_randint(root, num_gene - 1, 0); + + while (swap1 == swap2) + swap2 = geqo_randint(root, num_gene - 1, 0); + + temp = tour[swap1]; + tour[swap1] = tour[swap2]; + tour[swap2] = temp; + + + num_swaps -= 1; + } +} + +#endif /* defined(CX) */ |