def compute_performance(mnist,
weights,
biases,
layer_types,
noise_ratio=None,
repeat=1):
if noise_ratio is None:
noise_ratio = [0.0]
nn = BasicLenetModel()
nn.create_network(weights, biases, layer_types)
nn.create_initializer()
nn.initialize()
# compute power of input test images
norm_x = np.linalg.norm(mnist.test.images, axis=1)
acc = np.zeros(len(noise_ratio))
for k, g in enumerate(noise_ratio):
for _ in range(repeat):
# add noise to the test images
noise = np.random.normal(0, 1.0, mnist.test.images.shape)
norm_n = np.linalg.norm(noise, axis=1)
scale_n = g * norm_x / norm_n
noise = noise * scale_n[:, np.newaxis]
# compute accuracy
acc[k] += nn.compute_accuracy(mnist.test.images + noise,
mnist.test.labels)
acc[k] /= repeat
return acc
def compute_performance(mnist, weights, biases, layer_types):
nn = BasicLenetModel()
nn.create_network(weights, biases, layer_types)
nn.create_initializer()
nn.initialize()
signals = nn.get_fw_signals(mnist.train.images)
# sparsity and accuracy
acc = nn.compute_accuracy(mnist.test.images, mnist.test.labels)
nnz = [np.count_nonzero(np.abs(w) > 1e-6) for w in weights]
return acc, nnz, signals[-2]
def train_regulized_network(mnist,
l1_weight=None,
l2_weight=None,
keep_prob=1.0,
file_name=None):
if file_name is None:
file_name = result_folder + 'original_model.npz'
print('=' * 60)
print('l1 weight=', l1_weight, 'l2 weight=', l2_weight, 'keep prob.=',
keep_prob)
initial_weights, initial_biases, layer_types = load_network_parameters(
file_name)
nn = BasicLenetModel()
nn.create_network(initial_weights, initial_biases, layer_types)
nn.add_regulizer(l1_weight, l2_weight)
nn.create_optimizer(training_algorithm='Adam',
learning_rate=0.001,
decay_rate=0.98,
decay_step=500)
nn.create_initializer()
nn.initialize()
batch_size = 100
for k in range(8001):
x, y = mnist.train.next_batch(batch_size)
nn.train(x, y, keep_prob)
if k % 500 == 0:
acc = nn.compute_accuracy(mnist.validation.images,
mnist.validation.labels)
print('{0:2d}: learning rate={1:5.4f}, accuracy={2:2.3f} '.format(
k // 500, nn.learning_rate(), acc))
weights, biases = nn.get_weights()
layer_types = nn.get_layer_types()
nz = [np.count_nonzero(np.abs(w) > 1e-6) for w in weights]
acc = nn.compute_accuracy(mnist.test.images, mnist.test.labels)
s = ', '.join('{:.0f}'.format(v) for v in nz)
s = ' accuracy={0:4.2f}'.format(
acc * 100) + ', number of non-zero elements: ' + s
print(s)
np.savez_compressed(file_name, w=weights, b=biases, type=layer_types)
return weights, biases, layer_types
def parallel_nettrim(mnist, epsilon_gain, original_weights, original_biases,
layer_types):
nn = BasicLenetModel()
nn.create_network(original_weights, original_biases, layer_types)
nn.create_initializer()
nn.initialize()
# use all training samples
num_samples = mnist.train.images.shape[0]
samples_x, _ = mnist.train.next_batch(num_samples)
orig_Weights, orig_Biases = nn.get_weights()
layer_types = nn.get_layer_types()
signals = nn.get_fw_signals(samples_x)
num_layers = len(orig_Weights)
# pruning algorithm on all layers
unroll_number = 200
num_iterations = 10
nt = nt_tf.NetTrimSolver(unroll_number=unroll_number)
pruned_weights = copy.deepcopy(orig_Weights)
pruned_biases = copy.deepcopy(orig_Biases)
for layer in range(num_layers):
print(' Pruning layer ', layer)
if layer_types[layer] == 'conv':
print('Convolutional layer: skipping.')
continue
X = np.concatenate(
[signals[layer].transpose(),
np.ones((1, num_samples))])
Y = signals[layer + 1].transpose()
if layer < num_layers - 1:
# ReLU layer, use net-trim
V = np.zeros(Y.shape)
else:
# use sparse least-squares (for softmax, ignore the activation function)
V = None
norm_Y = np.linalg.norm(Y)
epsilon = epsilon_gain * norm_Y
start = time.time()
W_nt = nt.run(X, Y, V, epsilon, rho=100, num_iterations=num_iterations)
elapsed = time.time() - start
print('Elapsed time: {0:5.3f}'.format(elapsed))
Y_nt = np.matmul(W_nt.transpose(), X)
if layer < num_layers - 1:
Y_nt = np.maximum(Y_nt, 0)
rec_error = np.linalg.norm(Y - Y_nt)
nz_count = np.count_nonzero(W_nt > 1e-6)
print('non-zeros= {0}, epsilon= {1:.3f}, rec. error= {2:.3f}'.format(
nz_count, epsilon, rec_error))
pruned_weights[layer] = W_nt[:-1, :]
pruned_biases[layer] = W_nt[-1, :]
return pruned_weights, pruned_biases
# Net-Trim parameters:
# number of loops inside GPU
unroll_number = 10
# number of loops outside the GPU
num_iterations = 30
# relative value of epsilon for Net-Trim
epsilon_gain = 0.15
# create neural network and train
nn = BasicLenetModel()
nn.create_network()
nn.create_optimizer(training_algorithm='Adam', learning_rate=0.001, decay_rate=0.98, decay_step=500)
nn.create_initializer()
nn.initialize()
for k in range(mx_iter):
x, y = mnist.train.next_batch(batch_size)
nn.train(x, y, keep_prob)
if k % 500 == 0:
acc = nn.compute_accuracy(mnist.validation.images, mnist.validation.labels)
print('{0:2d}: learning rate={1:5.4f}, accuracy={2:2.3f} '.format(k // 500, nn.learning_rate(), acc))
org_acc = nn.compute_accuracy(mnist.test.images, mnist.test.labels)
#
# Net-Trim:
# change num_samples to a number, say 10000, if you want the Net-Trim retraining with only that many samples