Changeset 764

Timestamp:

03/28/18 02:29:34 (7 years ago)

Author:

Maciej Komosinski

Message:

Less deterministic (less absorbing) mutation for very narrow allowed ranges (performs reflect+wrap, previously reflect+absorb)

File:

• cpp/frams/genetics/oper_fx.cpp (modified) (1 diff)

cpp/frams/genetics/oper_fx.cpp

@@ -147 +147 @@
 {
         double result = mutateCreepNoLimit(type, current, stddev, limit_precision_3digits);
-        //TODO consider that when boundary is touched (reflect+absorb below), the requested precision (3 digits) may change. Is it good or bad?
-        //reflect:
-        if (result > mx) result = mx - (result - mx); else
-                if (result < mn) result = mn + (mn - result);
-        //absorb (just in case 'result' exceeded the allowed range so much):
-        if (result > mx) result = mx; else
-                if (result < mn) result = mn;
+        if (result<mn || result>mx) //exceeds boundary, so bring to the allowed range
+        {
+                //reflect:
+                if (result > mx) result = mx - (result - mx); else
+                        if (result < mn) result = mn + (mn - result);
+                //wrap (just in case 'result' exceeded the allowed range so much that after reflection above it exceeded the other boundary):
+                if (result > mx) result = mn + fmod(result - mx, mx - mn); else
+                        if (result < mn) result = mn + fmod(mn - result, mx - mn);
+                if (limit_precision_3digits)
+                {
+                        //reflect and wrap above may have changed the (limited) precision, so try to round again (maybe unnecessarily, because we don't know if reflect+wrap above were triggered)
+                        double result_try = floor(result * 1000 + 0.5) / 1000.0; //round
+                        if (mn <= result_try && result_try <= mx) result = result_try; //after rounding still witin allowed range, so keep rounded value
+                }
+        }
         return result;
 }