def test_eq(self):
"""
Ensures that only the chromosome is used for equality.
"""
x = Genome([1, 2, 3])
y = Genome([1, 2, 3])
z = Genome([3, 2, 1])
self.assertEqual(x, y)
self.assertNotEqual(x, z)
def test_return_parents_if_same(self):
"""
If both parents have the same chromosome then just return the parents.
"""
mum = Genome([1, 2, 3])
dad = Genome([1, 2, 3])
result = crossover(mum, dad, Genome)
self.assertEqual(mum, result[0],
"Child expected to be the same as parent.")
self.assertEqual(mum, result[0],
"Child expected to be the same as parent.")
def test_generate_function_returns_list(self):
"""
Ensures the new population is a list.
"""
generate_function = make_generate_function(7, 0.2, CANTUS_FIRMUS)
g1 = Genome([1, 2, 3])
g1.fitness = 1
g2 = Genome([1, 2, 3])
g2.fitness = 2
seed_population = [g1, g2]
result = generate_function(seed_population)
self.assertTrue(list, type(result))
def test_init(self):
"""
Ensures the chromosome and fitness are initialised correctly.
"""
x = Genome([1, 2, 3])
self.assertEqual(None, x.fitness)
self.assertEqual([1, 2, 3], x.chromosome)
def test_creates_two_babies(self):
"""
If the parents are different ensures that the children are the result
of an expected crossover.
"""
mum = Genome([1, 2, 3, 4])
dad = Genome(['a', 'b', 'c', 'd'])
result = crossover(mum, dad, Genome)
# There must be two children.
self.assertEqual(2, len(result))
# The randint call in crossover will choose 2 given random.seed(5).
expected1 = Genome([1, 2, 'c', 'd'])
expected2 = Genome(['a', 'b', 3, 4])
self.assertEqual(expected1, result[0],
"Expected: %r Got: %r" % (expected1, result[0]))
self.assertEqual(expected2, result[1],
"Expected: %r Got: %r" % (expected2, result[1]))
def test_generate_function_returns_list_of_correct_length(self):
"""
Ensure the new population is the correct length.
"""
generate_function = make_generate_function(7, 0.2, CANTUS_FIRMUS)
g1 = Genome([1, 2, 3])
g1.fitness = 1
g2 = Genome([1, 2, 3])
g2.fitness = 2
g3 = Genome([1, 2, 3])
g3.fitness = 3
seed_population = [g1, g2, g3]
result = generate_function(seed_population)
self.assertTrue(3, len(result))
def test_getitem(self):
"""
The __getitem__ function returns the corresponding result from the
chromosome.
"""
x = Genome([1, 2, 3])
self.assertEqual(1, x[0])
self.assertEqual(2, x[1])
self.assertEqual(3, x[2])
def test_returns_genome(self):
"""
Ensures that the roulette wheel returns a selected genome.
"""
class Genome(object):
"""
A simple representation of a genome.
"""
def __init__(self, fitness):
self.fitness = fitness
population = [Genome(random.uniform(0.1, 10.0)) for i in range(4)]
result = roulette_wheel_selection(population)
self.assertIsInstance(
result, Genome,
"Expected result of roulette_wheel_selection is not a Genome")
def test_returns_genome_with_unfit_population(self):
"""
Ensures that the roulette wheel returns a randomly selected genome if
none of them have a positive fitness score.
"""
class Genome(object):
"""
A simple representation of a genome.
"""
def __init__(self, fitness):
self.fitness = fitness
population = [Genome(0.0) for i in range(4)]
result = roulette_wheel_selection(population)
self.assertIsInstance(
result, Genome,
"Expected result of roulette_wheel_selection is not a Genome")
def test_generate_function_returns_list(self):
"""
Ensures the new population is a list.
"""
generate_function = make_generate_function(7, 0.2, CANTUS_FIRMUS)
g1 = Genome([1, 2, 3])
g1.fitness = 1
g2 = Genome([1, 2, 3])
g2.fitness = 2
seed_population = [g1, g2]
result = generate_function(seed_population)
self.assertTrue(list, type(result))
def test_breed(self):
"""
Ensures that the crossover function is called as a result of calling
the breed method.
"""
x = Genome([1, 2, 3, 4])
mate = Genome(['a', 'b', 'c', 'd'])
mock_crossover = MagicMock(return_value=(Genome([1, 2, 'a', 'b']),
Genome(['a', 'b', 3, 4])))
with patch('foox.ga.crossover', mock_crossover):
x.breed(mate)
self.assertEqual(
1, mock_crossover.call_count,
"Breed does not call crossover function expected number of times.")
mock_crossover.assert_called_with(x, mate, Genome)
def test_generate_function_returns_list_of_correct_length(self):
"""
Ensure the new population is the correct length.
"""
generate_function = make_generate_function(7, 0.2, CANTUS_FIRMUS)
g1 = Genome([1, 2, 3])
g1.fitness = 1
g2 = Genome([1, 2, 3])
g2.fitness = 2
g3 = Genome([1, 2, 3])
g3.fitness = 3
seed_population = [g1, g2, g3]
result = generate_function(seed_population)
self.assertTrue(3, len(result))
def test_repr(self):
"""
The __repr__ of the Genome is that of the chromosome.
"""
x = Genome([1, 2, 3])
self.assertEqual(repr([1, 2, 3]), repr(x))
def test_len(self):
"""
The __len__ function returns the length of the chromosome.
"""
x = Genome([1, 2, 3])
self.assertEqual(3, len(x))
def test_mutate(self):
"""
Ensurs the mutate method returns NotImplemented.
"""
x = Genome([1, 2, 3])
self.assertEqual(NotImplemented, x.mutate(1, 2, [1, 2, 3]))