def replacement(self, population: List[S], offspring_population: List[S]) -> List[List[S]]:
""" This method joins the current and offspring populations to produce the population of the next generation
by applying the ranking and crowding distance selection.
:param population: Parent population.
:param offspring_population: Offspring population.
:return: New population after ranking and crowding distance selection is applied.
"""
join_population = population + offspring_population
return RankingAndCrowdingDistanceSelection(self.population_size).execute(join_population)
class DominanceRankingTestCases(unittest.TestCase):
def setUp(self):
self.ranking_and_crowding_selection = RankingAndCrowdingDistanceSelection(
5)
def test_should_len_of_nsgaii_execute_be_5(self):
solution1 = Solution(2, 2)
solution2 = Solution(2, 2)
solution3 = Solution(2, 2)
solution4 = Solution(2, 2)
solution5 = Solution(2, 2)
solution6 = Solution(2, 2)
solution1.objectives[0] = 1.0
solution1.objectives[1] = 0.0
solution2.objectives[0] = 0.6
solution2.objectives[1] = 0.6
solution3.objectives[0] = 0.5
solution3.objectives[1] = 0.5
solution4.objectives[0] = 1.1
solution4.objectives[1] = 0.0
solution5.objectives[0] = 0.0
solution5.objectives[1] = 1.0
solution6.objectives[0] = 1.05
solution6.objectives[1] = 0.1
solution_list = [
solution1, solution2, solution3, solution4, solution5, solution6
]
list_of_crowding_and_rankings = self.ranking_and_crowding_selection.execute(
solution_list)
self.assertEqual(len(list_of_crowding_and_rankings), 5)
self.assertEqual(solution1, list_of_crowding_and_rankings[0])
self.assertEqual(solution3, list_of_crowding_and_rankings[1])
self.assertEqual(solution5, list_of_crowding_and_rankings[2])
self.assertEqual(solution4, list_of_crowding_and_rankings[3])
self.assertEqual(solution2, list_of_crowding_and_rankings[4])
def setUp(self):
self.ranking_and_crowding_selection = RankingAndCrowdingDistanceSelection(
5)
def replacement(self, population: List[S],
offspring_population: List[S]) -> List[List[TypeVar('S')]]:
join_population = population + offspring_population
return RankingAndCrowdingDistanceSelection(
self.population_size).execute(join_population)
