Changeset 1330 for cpp/frams

Timestamp:

01/02/25 02:00:48 (5 days ago)

Author:

Maciej Komosinski

Message:

f9: less diversifying, more distance-preserving (DPX) crossover (children now have a similar length to parents). Additionally, avoids cutpoints that would cause a simple swap of complete parent genotypes.

File:

• cpp/frams/genetics/f9/f9_oper.cpp (modified) (4 diffs)

cpp/frams/genetics/f9/f9_oper.cpp

@@ -1 +1 @@
 // This file is a part of Framsticks SDK.  http://www.framsticks.com/
-// Copyright (C) 1999-2021  Maciej Komosinski and Szymon Ulatowski.
+// Copyright (C) 1999-2024  Maciej Komosinski and Szymon Ulatowski.
 // See LICENSE.txt for details.
 
@@ -81 +81 @@
 }
 
-///Simple mutation
+///A simple mutation
 int GenoOper_f9::mutate(char *&gene, float &chg, int &method)
 {
@@ -123 +123 @@
 int GenoOper_f9::crossOver(char *&g1, char *&g2, float& chg1, float& chg2)
 {
+        // printf("%s  \t  %s\n", g1, g2);
         int len1 = (int)strlen(g1), len2 = (int)strlen(g2);
-        int p1 = rndUint(len1);  //random cut point for the first genotype
-        int p2 = rndUint(len2);  //random cut point for the second genotype
+        double p = rndDouble(1); //random cut point
+        int p1 = 1 + int(p * (len1 - 1));  //...mapped to the first parent, avoiding cuts that would cause a simple swap of the entire genotype. Unavoidable for a single-letter parent
+        int p2 = 1 + int(p * (len2 - 1));  //...mapped to the second parent, as above
         char *child1 = (char*)malloc(p1 + len2 - p2 + 1);
         char *child2 = (char*)malloc(p2 + len1 - p1 + 1);
@@ -132 +134 @@
         free(g1); g1 = child1;
         free(g2); g2 = child2;
+        //children non-empty if parents non-empty (valid)
         chg1 = (float)p1 / strlen(child1);
         chg2 = (float)p2 / strlen(child2);
+        // printf("%s  \t  %s\n", child1, child2);
+        // printf("%g  \t  %g\n", chg1, chg2);
         return GENOPER_OK;
 }