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) */