Changeset 1157 for cpp/frams/genetics/f9/f9_oper.cpp

Timestamp:

10/01/21 22:52:19 (3 years ago)

Author:

Maciej Komosinski

Message:

Improved f9 mutation

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) 1999-2020  Maciej Komosinski and Szymon Ulatowski.
+// Copyright (C) 1999-2021  Maciej Komosinski and Szymon Ulatowski.
 // See LICENSE.txt for details.
 
@@ -7 +7 @@
 #include <common/nonstd.h> //rndUint, rndDouble
 #include <string.h>
+#include <assert.h>
 
 
@@ -13 +14 @@
 {
         { "Genetics: f9", 1, 1, },
-        { "f9_mut", 0, 0, "Mutation probability", "f 0 1 0.1", FIELD(mut_prob), "How many genes should be mutated during single mutation (1=all genes, 0.1=ten percent)", },
+        { "f9_mut", 0, 0, "Mutation probability", "f 0 1 0", FIELD(mut_prob), "How many genes should be mutated during single mutation (1=all genes, 0.1=ten percent, 0=one gene)", },
         { 0, },
 };
@@ -47 +48 @@
 }
 
-///Very simple mutation
+void GenoOper_f9::mutate_replace(char *gene, int i)
+{
+        char oldgene = gene[i];
+        const char *pos = strchr(turtle_commands_f9, oldgene);
+        if (pos == NULL) //gene not in the set of allowed commands
+                gene[i] = turtle_commands_f9[rndUint(turtle_commands_f9_count)];
+        else
+                gene[i] = turtle_commands_f9[((pos - turtle_commands_f9) + 1 + rndUint(turtle_commands_f9_count - 1)) % turtle_commands_f9_count]; //always change to a different command
+        //printf("%c %c\n", oldgene, gene[i]);
+        assert(gene[i] != oldgene);
+}
+
+void GenoOper_f9::mutate_add_or_del(char *& gene, int len, int add_0_del_1)
+{
+        string newgeno(gene);
+        if (add_0_del_1 == 0) //add
+        {
+                int p = rndUint(len + 1);  //random location
+                //printf("before add: %s\n",(const char*)newgeno);
+                newgeno = newgeno.substr(0, p) + string(turtle_commands_f9 + rndUint(turtle_commands_f9_count), 1) + newgeno.substr(p);
+                //printf("after add: %s\n",(const char*)newgeno);
+        }
+        else //delete
+        {
+                int p = rndUint(len);  //random location
+                //printf("before delete: %s\n",(const char*)newgeno);
+                newgeno = newgeno.substr(0, p) + newgeno.substr(p + 1);
+                //printf("after delete: %s\n",(const char*)newgeno);
+        }
+        free(gene);
+        gene = strdup(newgeno.c_str()); //reallocate
+}
+
+///Simple mutation
 int GenoOper_f9::mutate(char *&gene, float &chg, int &method)
 {
         method = 0;
         int changes = 0, len = strlen(gene);
-        int symbols = strlen(turtle_commands_f9);
 
-        for (int i = 0; i < len; i++)
-        {
-                if (rndDouble(1) < mut_prob) //normalize prob with the length of the genotype
+        if (mut_prob > 0)
+                for (int i = 0; i < len; i++)
                 {
-                        char oldgene = gene[i];
-                        gene[i] = turtle_commands_f9[rndUint(symbols)];
-                        if (gene[i] != oldgene) changes++;
+                        if (rndDouble(1) < mut_prob) //normalize prob with the length of the genotype
+                        {
+                                mutate_replace(gene, i);
+                                changes++;
+                        }
                 }
-        }
 
         if (rndDouble(1) < mut_prob) //add or delete a random char
         {
-                SString newgeno(gene);
-                if (rndUint(2) == 0) //add
-                {
-                        int symbols = strlen(turtle_commands_f9);
-                        int p = rndUint(len + 1);  //random location
-                        //printf("before add: %s\n",(const char*)newgeno);
-                        newgeno = newgeno.substr(0, p) + SString(turtle_commands_f9 + rndUint(symbols), 1) + newgeno.substr(p);
-                        //printf("after add: %s\n",(const char*)newgeno);
-                        changes++;
-                }
-                else if (len > 1) //delete
-                {
-                        int p = rndUint(len);  //random location
-                        //printf("before delete: %s\n",(const char*)newgeno);
-                        newgeno = newgeno.substr(0, p) + newgeno.substr(p + 1);
-                        //printf("after delete: %s\n",(const char*)newgeno);
-                        changes++;
-                }
-                free(gene);
-                gene = strdup(newgeno.c_str()); //reallocate
+                int change_add_or_del = 1 + (len > 1); //either add a new symbol (1), or delete a random symbol (+(len>1))
+                int add_0_del_1 = rndUint(change_add_or_del);
+                mutate_add_or_del(gene, len, add_0_del_1);
+                changes++;
+        }
+
+        if (changes == 0) //if nothing changed so far, then fallback to minimal change: always changes one symbol
+        {
+                int change_what = len + 1 + (len > 1); //either replace an existing gene, or add a new symbol (+1), or delete a random symbol (+(len>1))
+                int change_selected = rndUint(change_what);
+                if (change_selected < len)
+                        mutate_replace(gene, change_selected);
+                else
+                        mutate_add_or_del(gene, len, change_selected - len);
+                changes++;
         }
 
         chg = (float)changes / len;
-        return changes > 0 ? GENOPER_OK : GENOPER_OPFAIL; //no changes => OPFAIL so that GenMan will call mutate again
+        return changes > 0 ? GENOPER_OK : GENOPER_OPFAIL; //no changes? (should never happen) => OPFAIL so that GenMan will call mutate again
 }