Add minimal mutation probability

aimclub · Jul 31, 2023 · 525bb7b · 525bb7b
1 parent 5627573
commit 525bb7b
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Showing 2 changed files with 5 additions and 1 deletion.
diff --git a/golem/core/optimisers/genetic/gp_optimizer.py b/golem/core/optimisers/genetic/gp_optimizer.py
@@ -127,6 +127,9 @@ def _update_requirements(self):
         if not self.generations.is_any_improved:
             self.graph_optimizer_params.mutation_prob, self.graph_optimizer_params.crossover_prob = \
                 self._operators_prob.next(self.population)
+            self.log.info(
+                f'Next mutation proba: {self.graph_optimizer_params.mutation_prob}; '
+                f'Next crossover proba: {self.graph_optimizer_params.crossover_prob}')
         self.graph_optimizer_params.pop_size = self._pop_size.next(self.population)
         self.requirements.max_depth = self._graph_depth.next()
         self.log.info(

diff --git a/golem/core/optimisers/genetic/parameters/mutation_prob.py b/golem/core/optimisers/genetic/parameters/mutation_prob.py
@@ -9,6 +9,7 @@ class AdaptiveMutationProb(AdaptiveParameter[float]):
     def __init__(self, default_prob: float = 0.5):
         self._current_std = 0.
         self._max_std = 0.
+        self._min_proba = 0.05
         self._default_prob = default_prob
 
     @property
@@ -23,7 +24,7 @@ def next(self, population: PopulationT) -> float:
         elif self._max_std == 0:
             mutation_prob = self._default_prob
         else:
-            mutation_prob = 1. - (self._current_std / self._max_std)
+            mutation_prob = max(1. - (self._current_std / self._max_std), self._min_proba)
         return mutation_prob
 
     def _update_std(self, population: PopulationT):