def test_identity():
x = ad.Variable(name='x')
y = ad.Variable(name='y')
z = x / y + x / 2. + 4
z_grad_x, z_grad_y = ad.gradients(z, [x, y])
executor = ad.Executor([z, z_grad_x, z_grad_y])
x_val = 2 * np.ones(1)
y_val = 3 * np.ones(1)
z_val, z_grad_x, z_grad_y = executor.run(feed_shapes={x: x_val, y: y_val})
print(z_val, z_grad_x, z_grad_y)
def test_softmax():
x2_pred = ad.Variable(name='x2_pred')
x2_actu = ad.Variable(name='x2_actu')
y = th.nn.softmax_cross_entropy_with_logits(x2_pred, x2_actu)
x2_pred_grad, x2_actu_grad = ad.gradients(y, [x2_pred, x2_actu])
x2_pred_val = np.array([[0.8, 0.01, 0.5], [0.8, 0.01, 0.5]])
x2_actu_val = np.array([[1.0, 1.0, 0], [1.0, 1.0, 0]])
executor = ad.Executor([y, x2_pred_grad, x2_actu_grad])
y_val, x2_pred_grad_val, x2_actu_grad_val = executor.run(
feed_shapes={
x2_pred: x2_pred_val,
x2_actu: x2_actu_val
})
def test_broadcast_to():
x2 = ad.Variable(name='x2')
x3 = ad.Variable(name='x3')
y = ad.broadcast_to(x2, x3)
grad_x2, grad_x3 = ad.gradients(y, [x2, x3])
executor = ad.Executor([y, grad_x2, grad_x3])
x2_val = np.array([[1, 2, 3]])
x3_val = np.zeros((3, 3))
y_val, grad_x2_val, grad_x3_val = executor.run(feed_shapes={
x2: x2_val,
x3: x3_val
})
# asserts
assert isinstance(y, ad.Node)
assert np.array_equal(y_val, np.array([[1, 2, 3], [1, 2, 3], [1, 2, 3]]))
assert np.array_equal(grad_x2_val, np.array([3, 3, 3]))
def test_reducesum():
x2 = ad.Variable(name='x2')
y = ad.reduce_sum(x2)
grad_x2, = ad.gradients(y, [x2])
executor = ad.Executor([y, grad_x2])
x2_val = np.array([[1, 2, 3], [4, 5, 6]])
y_val, grad_x2_val = executor.run(feed_shapes={x2: x2_val})
assert isinstance(y, ad.Node)
assert np.array_equal(y_val, np.array([5, 7, 9]))
assert np.array_equal(grad_x2_val, np.array([1, 1, 1]))
def test_sigmoid():
x = ad.Variable(name='x')
y = th.nn.sigmoid(x)
grad_x, = ad.gradients(y, [x])
executor = ad.Executor([y, grad_x])
x_val = np.array([-100, 0, 100])
y_val, grad_x_val = executor.run(feed_shapes={x: x_val})
print(y_val, grad_x_val)
def test_relu():
x = ad.Variable(name='x')
y = th.nn.relu(x)
grad_x2, = ad.gradients(y, [x])
executor = ad.Executor([y, grad_x2])
x_val = np.array([[-1, 2, 3], [1, -2, 0]])
y_val, grad_x2_val = executor.run(feed_shapes={x: x_val})
expected_y_val = np.array([[0, 2, 3], [1, 0, 0]])
expected_x2_grad = np.array([[0, 1, 1], [1, 0, 0]])
assert np.array_equal(y_val, expected_y_val)
assert np.array_equal(grad_x2_val, expected_x2_grad)
def test_matmul():
x = ad.Variable(name='x')
y = ad.Variable(name='y')
z = ad.matmul(x, y)
z_grad_x, z_grad_y = ad.gradients(z, [x, y])
executor = ad.Executor([z, z_grad_x, z_grad_y])
x_val = np.array([[1, 2], [3, 4], [5, 6]]) # 3x2
y_val = np.array([[7, 8, 9], [10, 11, 12]]) # 2x3
z_val, z_grad_x, z_grad_y = executor.run(feed_shapes={x: x_val, y: y_val})
expected_yval = np.matmul(x_val, y_val)
expected_grad_x_val = np.matmul(np.ones_like(expected_yval),
np.transpose(y_val))
expected_grad_y_val = np.matmul(x_val.T, np.ones_like(expected_yval))
assert np.array_equal(expected_yval, z_val)
assert np.array_equal(expected_grad_x_val, z_grad_x)
assert np.array_equal(expected_grad_y_val, z_grad_y)
start_time = datetime.datetime.now()
use_gpu = True
# use_gpu = False
data = th.datasets.MNIST(batch_size=128)
batch_generator = data.train_batch_generator()
input_size = data.num_features()
hid_1_size = 256
hid_2_size = 100
output_size = 10
lr = 1e-3
X = ad.Variable(name="X")
y = ad.Variable(name='y')
loss, W1, b1, W2, b2, W3, b3, logit = build_graph(X, y, input_size, hid_1_size, hid_2_size, output_size)
optimizer = th.optim.SGD(loss, params=[W1, b1, W2, b2, W3, b3], lr=lr, use_gpu=use_gpu)
for i in range(10000):
X_batch, y_batch = next(batch_generator)
loss_now = optimizer.step(feed_dict={X: X_batch, y: y_batch})
if i <= 10 or (i <= 100 and i % 10 == 0) or (i <= 1000 and i % 100 == 0) or (i <= 10000 and i % 500 == 0):
fmt_str = 'iter: {0:>5d} cost: {1:>8.5f}'
print(fmt_str.format(i, loss_now[0]))
val_acc = measure_accuracy(logit, data.validation(), use_gpu=use_gpu)
print('Validation accuracy: {:>.2f}'.format(val_acc))