Added property access to survival rates

manduca/Population.py

@@ -13,6 +13,24 @@ class GenerationInfo(namedtuple('GenerationInfo', ['generation_number', 'fitness
    def max_fitness(self):
       return max(self.fitness_values)
 
+   @property
+   def child_survival_rate(self):
+       if self.num_matings is None:
+           return None
+       return float(self.surviving_children) / self.num_matings
+
+   @property
+   def mutant_survival_rate(self):
+       if self.num_mutants is None:
+           return None
+       return float(self.surviving_mutants) / self.num_mutants
+
+   @property
+   def parent_survival_rate(self):
+       if self.num_ancestors is None:
+           return None
+       return float(self.surviving_ancestors) / self.num_ancestors
+
 class EvolutionParameters(object):
    def __init__(self, max_population, num_matings, num_mutants, max_mutations, **kwargs):
       self.max_population = max_population