def test_point_cross_over_max(self):
size = 4
cross_point = 2
chromosome_1 = utils.max_binary_value(size)
chromosome_2 = utils.max_binary_value(size)
expected = utils.max_binary_value(size)
individual_1, individual_2 = point_cross_over(chromosome_1,
chromosome_2, size,
cross_point)
self.assertEqual(individual_1, expected)
self.assertEqual(individual_2, expected)
def __create_next_generation__(self):
next_generation = []
while len(next_generation) != self.population_size:
# select parents
parents = self.select_parents_callback(self.current_individuals)
if len(parents) != 2:
raise Exception('Parent selection must return two individuals')
# create progeny
chromosomes = self.crossover_callback(*parents)
current_index = 0
while current_index < len(chromosomes) and len(
next_generation) != self.population_size:
# mutation (defaulted to flip mutation)
chromosome = self.mutate_callback(chromosomes[current_index])
if not 0 <= chromosome <= utils.max_binary_value(
self.chromosome_size):
raise Exception(
'Chromosomes generated must be between within max chromosome value'
)
# create individual
individual = Individual(self.chromosome_size, chromosome)
individual.set_parents(*parents)
next_generation.append(individual)
current_index += 1
return next_generation
def chromosome_subset_value(chromosome, start, length):
if start <= 0:
raise ValueError('Start position has to be greater than or equal to 1')
shifted_chromosome = utils.shift_bytes(chromosome, start - 1)
mask = utils.max_binary_value(length)
return utils.apply_mask(shifted_chromosome, mask)
def junction_cross_over(chromosome_1: int, chromosome_2: int, size: int, point_1: int, point_2: int) -> Tuple[int, int]:
max_val = utils.max_binary_value(size)
mask_1 = utils.shift_bytes(max_val, point_1)
mask_2 = utils.shift_bytes(max_val, point_2)
mask = mask_1 | ~mask_2
return create_offspring_from_mask(chromosome_1, chromosome_2, mask)
def point_cross_over(chromosome_1: int, chromosome_2: int, size: int, point: int) -> Tuple[int, int]:
max_val = utils.max_binary_value(size)
mask = utils.shift_bytes(max_val, point)
return create_offspring_from_mask(chromosome_1, chromosome_2, mask)
def test_max_binary_value_one(self):
size = 1
self.assertEqual(1, utils.max_binary_value(size))
def test_max_binary_value_zero(self):
size = 0
self.assertEqual(0, utils.max_binary_value(size))
def test_max_binary_value_normal(self):
size = 4
self.assertEqual(15, utils.max_binary_value(size))