def test_calculate_updates():
"""Test calculate_updates method"""
X = np.array([[0, 1, 0, 1], [0, 0, 0, 0], [1, 1, 1, 1], [1, 1, 1, 1],
[0, 0, 1, 1], [1, 0, 0, 0]])
y = np.reshape(np.array([1, 1, 0, 0, 1, 1]), [6, 1])
nodes = [4, 2, 1]
fitness = NetworkWeights(X,
y,
nodes,
activation=identity,
bias=False,
is_classifier=False,
learning_rate=1)
a = list(np.arange(8) + 1)
b = list(0.01 * (np.arange(2) + 1))
weights = a + b
fitness.evaluate(weights)
updates = fitness.calculate_updates()
update1 = np.array([[-0.0017, -0.0034], [-0.0046, -0.0092],
[-0.0052, -0.0104], [0.0014, 0.0028]])
update2 = np.array([[-3.17], [-4.18]])
assert (np.allclose(updates[0], update1, atol=0.001)
and np.allclose(updates[1], update2, atol=0.001))
def test_gradient_descent():
"""Test gradient_descent function"""
X = np.array([[0, 1, 0, 1], [0, 0, 0, 0], [1, 1, 1, 1], [1, 1, 1, 1],
[0, 0, 1, 1], [1, 0, 0, 0]])
y = np.reshape(np.array([1, 1, 0, 0, 1, 1]), [6, 1])
nodes = [4, 2, 1]
fitness = NetworkWeights(X,
y,
nodes,
activation=identity,
bias=False,
is_classifier=False,
learning_rate=0.1)
problem = ContinuousOpt(10,
fitness,
maximize=False,
min_val=-1,
max_val=1,
step=0.1)
test_weights = np.array([1, 1, 1, 1, 1, 1, 1, 1, 1, 1])
test_fitness = -1 * problem.eval_fitness(test_weights)
best_state, best_fitness, _ = gradient_descent(problem)
assert (len(best_state) == 10 and min(best_state) >= -1
and max(best_state) <= 1 and best_fitness < test_fitness)
def test_evaluate_no_bias_classifier():
"""Test evaluate method for binary classifier with no bias term"""
X = np.array([[0, 1, 0, 1], [0, 0, 0, 0], [1, 1, 1, 1], [1, 1, 1, 1],
[0, 0, 1, 1], [1, 0, 0, 0]])
y = np.reshape(np.array([1, 1, 0, 0, 1, 1]), [6, 1])
nodes = [4, 2, 1]
fitness = NetworkWeights(X, y, nodes, activation=identity, bias=False)
a = list(np.arange(8) + 1)
b = list(0.01 * (np.arange(2) + 1))
weights = a + b
assert round(fitness.evaluate(weights), 4) == 0.7393
def test_evaluate_no_bias_multi():
"""Test evaluate method for multivariate classifier with no bias
term"""
X = np.array([[0, 1, 0, 1], [0, 0, 0, 0], [1, 1, 1, 1], [1, 1, 1, 1],
[0, 0, 1, 1], [1, 0, 0, 0]])
y = np.array([[1, 1], [1, 0], [0, 0], [0, 0], [1, 0], [1, 1]])
nodes = [4, 2, 2]
fitness = NetworkWeights(X, y, nodes, activation=identity, bias=False)
a = list(np.arange(8) + 1)
b = list(0.01 * (np.arange(4) + 1))
weights = a + b
assert round(fitness.evaluate(weights), 4) == 0.7183
def test_evaluate_bias_regressor():
"""Test evaluate method for regressor with bias term"""
X = np.array([[0, 1, 0, 1], [0, 0, 0, 0], [1, 1, 1, 1], [1, 1, 1, 1],
[0, 0, 1, 1], [1, 0, 0, 0]])
y = np.reshape(np.array([1, 1, 0, 0, 1, 1]), [6, 1])
nodes = [5, 2, 1]
fitness = NetworkWeights(X,
y,
nodes,
activation=identity,
bias=True,
is_classifier=False)
a = list(np.arange(10) + 1)
b = list(0.01 * (np.arange(2) + 1))
weights = a + b
assert round(fitness.evaluate(weights), 4) == 0.4363
def test_gradient_descent_iter1():
"""Test gradient_descent function gets the correct answer after a
single iteration"""
X = np.array([[0, 1, 0, 1], [0, 0, 0, 0], [1, 1, 1, 1], [1, 1, 1, 1],
[0, 0, 1, 1], [1, 0, 0, 0]])
y = np.reshape(np.array([1, 1, 0, 0, 1, 1]), [6, 1])
nodes = [4, 2, 1]
fitness = NetworkWeights(X,
y,
nodes,
activation=identity,
bias=False,
is_classifier=False,
learning_rate=0.1)
problem = ContinuousOpt(10,
fitness,
maximize=False,
min_val=-1,
max_val=1,
step=0.1)
init_weights = np.array([1, 1, 1, 1, 1, 1, 1, 1, 1, 1])
best_state, best_fitness, _ = gradient_descent(problem,
max_iters=1,
init_state=init_weights)
x = np.array([-0.7, -0.7, -0.9, -0.9, -0.9, -0.9, -1, -1, -1, -1])
assert (np.allclose(best_state, x, atol=0.001)
and round(best_fitness, 2) == 19.14)
def _build_problem_and_fitness_function(X,
y,
node_list,
activation,
learning_rate,
bias,
clip_max,
is_classifier=True):
# Initialize optimization problem
fitness = NetworkWeights(X,
y,
node_list,
activation,
bias,
is_classifier,
learning_rate=learning_rate)
num_nodes = _NNBase._calculate_state_size(node_list)
problem = ContinuousOpt(length=num_nodes,
fitness_fn=fitness,
maximize=False,
min_val=-1 * clip_max,
max_val=clip_max,
step=learning_rate)
return fitness, problem