def test_gradientDescent(self):
theta = np.zeros((2,1))
iterations = 1500
alpha = 0.01
converged_theta = gradientDescent(self.X, self.y, theta, alpha, iterations)
self.assertAlmostEqual(converged_theta[0], -3.63, places=2)
self.assertAlmostEqual(converged_theta[1], 1.17, places=2)
self.assertAlmostEqual(hypothesis(np.array([1,3.5]),converged_theta), 0.45, places=2)
self.assertAlmostEqual(hypothesis(np.array([1,7]),converged_theta), 4.53, places=2)
def test_prediction(self):
self.X = np.concatenate([np.ones((self.m, 1)), self.X], axis=1)
theta = np.zeros((self.n + 1, 1))
theta_optimized, _ = gradient_descent(self.X, self.y, theta)
test_data = np.array([1, 45, 85]).reshape((1, 3))
prediction = hypothesis(test_data, theta_optimized)
self.assertAlmostEqual(prediction, 0.776, places=3)
self.assertEqual(classify(test_data, self.X, theta_optimized), 1)
def use_function(self, vector):
vector = np.insert(vector, 0, 1)
new_vector = []
if self.feature_scaling_coeficient is not None:
for i in range(len(vector)):
new_vector.append(
utils.feature_scaling_corrector(
vector[i], self.feature_scaling_coeficient[i]))
else:
new_vector = vector
print(new_vector)
return utils.hypothesis(self.theta_values, new_vector)
def test_classify_all(self):
m,n = self.X.shape
_,K = self.y.shape
X = np.hstack(( np.ones((m,1)), self.X ))
initial_theta = np.zeros((n+1,K))
lamda = 0.1
theta = classifyall(initial_theta, X, self.y, lamda)
hypo = hypothesis(X, theta)
predicted_y = hypo.argmax(axis=1)
expected_y = np.array([ d if d!=10 else 0 for d in self.data['y'].reshape(-1)])
acc = accuracy(predicted_y,expected_y)
self.assertAlmostEqual(acc, 94.9, places=0) # I can't get 94.9, only 94.64.... close enough I guess
def test_classify_all(self):
m, n = self.X.shape
_, K = self.y.shape
X = np.hstack((np.ones((m, 1)), self.X))
initial_theta = np.zeros((n + 1, K))
lamda = 0.1
theta = classifyall(initial_theta, X, self.y, lamda)
hypo = hypothesis(X, theta)
predicted_y = hypo.argmax(axis=1)
expected_y = np.array(
[d if d != 10 else 0 for d in self.data['y'].reshape(-1)])
acc = accuracy(predicted_y, expected_y)
self.assertAlmostEqual(
acc, 94.9,
places=0) # I can't get 94.9, only 94.64.... close enough I guess
def test_gradient_descent(self):
iterations = 400
alpha = 0.01 #[0.01, 0.03, 0.1, 0.3, 1.0]
m,n = self.X.shape
theta = np.zeros((n+1,1))
# add x_0 and do feature normalization on the rest of the columns
self.X = np.concatenate([np.ones((self.m,1)),self.X],axis=1)
self.X[:,1:n+1], mu, sigma = feature_normalization(self.X[:,1:n+1])
theta = gradientDescent(self.X, self.y, theta, alpha, iterations)
test = np.array([1.0, 1650.0, 3.0]).reshape((3,1))
test[1:,:] = ( test[1:,:] - mu ) / sigma
test = test.reshape((1,3)) # m=1, n=2, because there is 1 test case, with 2 features in it
self.assertAlmostEqual(hypothesis(test, theta), 289314.62, places=2)
def test_plot_decision_boundary(self):
negatives = self.data[self.data[:, 2] ==
0] # SELECT * FROM self.data WHERE col2 == 0
positives = self.data[self.data[:, 2] ==
1] # SELECT * FROM self.data WHERE col2 == 1
plt.xlabel("Microchip Test 1")
plt.ylabel("Microchip Test 2")
plt.scatter(negatives[:, 0],
negatives[:, 1],
c='y',
marker='o',
s=40,
linewidths=1,
label="y=0")
plt.scatter(positives[:, 0],
positives[:, 1],
c='b',
marker='+',
s=40,
linewidths=2,
label="y=1")
dimension = 6
X_mapped = map_feature(self.X[:, 0], self.X[:, 1], dimension)
m, n = X_mapped.shape
X_mapped = np.hstack((np.ones((m, 1)), X_mapped))
theta = np.zeros((n + 1, 1))
lamda = 1.0
theta_optimized, min_cost = regularized_gradient_descent(
X_mapped, self.y, theta, lamda)
x1 = np.linspace(-1, 1.5, 50)
x2 = np.linspace(-1, 1.5, 50)
X1, X2 = np.meshgrid(x1, x2)
hypo = np.zeros((len(x1), len(x2)))
for i in range(0, len(x1)):
for j in range(0, len(x2)):
mapped = map_feature(
np.array([X1[i][j]]).reshape((1, 1)),
np.array([X2[i][j]]).reshape((1, 1)), dimension)
mapped = np.hstack((np.ones((1, 1)), mapped))
hypo[i][j] = hypothesis(mapped, theta_optimized)[0]
plt.contour(X1, X2, hypo, [0.5], label='Decision Boundary')
plt.legend()
plt.show()
def test_normal_quation(self):
self.X = np.concatenate([np.ones((self.m,1)),self.X],axis=1)
theta = normal_equation(self.X, self.y)
test = np.array([1.0, 1650.0, 3.0]).reshape((1,3))
self.assertAlmostEqual(hypothesis(test, theta), 293081.46, places=2)
