def test_should_encode_values(self):
# given
bits = 4 # 2^bits discrete states
encoder = RealValueEncoder(bits)
# then
assert 0 == encoder.encode(0.0)
assert 7 == encoder.encode(0.5)
assert 15 == encoder.encode(1.0)
def _mutate_attribute(ubr: UBR, encoder: RealValueEncoder, noise_max: float,
mu: float):
if np.random.random() < mu:
noise = np.random.uniform(-noise_max, noise_max)
x1p = encoder.decode(ubr.x1)
ubr.x1 = encoder.encode(x1p, noise)
if np.random.random() < mu:
noise = np.random.uniform(-noise_max, noise_max)
x2p = encoder.decode(ubr.x2)
ubr.x2 = encoder.encode(x2p, noise)
def _widen_attribute(ubr: UBR, encoder: RealValueEncoder, noise_max: float,
mu: float):
# TODO: we should modify both condition and effect parts with the
# same noise.
if np.random.random() < mu:
noise = np.random.uniform(-noise_max, noise_max)
x1p = encoder.decode(ubr.x1)
ubr.x1 = encoder.encode(x1p, noise)
if np.random.random() < mu:
noise = np.random.uniform(-noise_max, noise_max)
x2p = encoder.decode(ubr.x2)
ubr.x2 = encoder.encode(x2p, noise)
def test_should_encode_with_noise_added(self):
# given
encoder = RealValueEncoder(16)
noise_max = 0.1
for _ in range(100):
# when
val = random.random()
encoded = encoder.encode(val)
encoded_with_noise = encoder.encode(val, noise_max)
# then
assert encoded_with_noise <= encoder.range[1]
assert encoded_with_noise >= encoded
def test_should_deny_encoding_illegal_values(self):
# given
encoder = RealValueEncoder(2)
# when
with pytest.raises(ValueError) as e1:
encoder.encode(-0.2)
with pytest.raises(ValueError) as e2:
encoder.encode(1.1)
# then
assert e1 is not None
assert e2 is not None
def test_encode_should_return_integer(self, _p):
# given
encoder = RealValueEncoder(2)
# when
encoded = encoder.encode(_p)
# then
assert type(encoded) is int
def test_should_encode_and_decode_approximately(self):
# given
encoder = RealValueEncoder(8)
epsilon = 0.01
observation = random.random()
# when
encoded = encoder.encode(observation)
decoded = encoder.decode(encoded)
# then
assert abs(observation - decoded) < epsilon