Files
EasyGA/survivor/Survivor.py

49 lines
1.5 KiB
Python

import random
# Import all survivor decorators
from decorators import *
def fill_in_best(ga):
"""Fills in the next population with the best chromosomes from the last population"""
needed_amount = len(ga.population) - len(ga.population.next_population)
ga.population.append_children(ga.population[:needed_amount])
def fill_in_random(ga):
"""Fills in the next population with random chromosomes from the last population"""
needed_amount = len(ga.population) - len(ga.population.next_population)
ga.population.append_children(random.sample(ga.population, needed_amount))
def fill_in_parents_then_random(ga):
"""Fills in the next population with all parents followed by random chromosomes from the last population"""
# Remove dupes from the mating pool
mating_pool = set(ga.population.mating_pool)
needed_amount = len(ga.population) - len(ga.population.next_population)
parent_amount = min(needed_amount, len(mating_pool))
random_amount = needed_amount - parent_amount
# Only parents are used.
if random_amount == 0:
ga.population.append_children(
chromosome
for i, chromosome
in enumerate(mating_pool)
if i < parent_amount
)
# Parents need to be removed from the random sample to avoid dupes.
else:
ga.population.append_children(mating_pool)
ga.population.append_children(
random.sample(
set(ga.population) - mating_pool,
random_amount
)
)