def test_should_decode_values(self):
# given
bits = 4
encoder = RealValueEncoder(bits)
# then
assert 0.0 == encoder.decode(0)
assert abs(0.5 - encoder.decode(8)) < 0.05
assert 1.0 == encoder.decode(15)
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_deny_illegal_values_when_decoding(self):
# given
encoder = RealValueEncoder(2)
# when
with pytest.raises(ValueError) as e1:
encoder.decode(-1)
with pytest.raises(ValueError) as e2:
encoder.decode(5)
# then
assert e1 is not None
assert e2 is not None
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