def main():
train_X, test_X, train_Y, test_Y = get_normalized_data()
model = ANN([500, 300])
session = tf.InteractiveSession()
model.set_session(session)
model.fit(train_X, train_Y, test_X, test_Y, show_fig=True)
print("Train accuracy:", model.score(train_X, train_Y))
print("Test accuracy:", model.score(test_X, test_Y))
def main():
max_iter = 20
print_period = 50
train_X, test_X, train_Y, test_Y = get_normalized_data()
learning_rate = 0.00004
reg = 0.01
train_Y_ind = indicator(train_Y)
test_Y_ind = indicator(test_Y)
N, D = train_X.shape
batch_size = 500
batch_num = N // batch_size
M = 300
K = 10
W1_init = np.random.randn(D, M) / np.sqrt(D)
b1_init = np.zeros(M)
W2_init = np.random.randn(M, K) / np.sqrt(M)
b2_init = np.zeros(K)
#initialize theano variables
thX = T.matrix('X')
thT = T.matrix('T')
W1 = theano.shared(W1_init, 'W1')
W2 = theano.shared(W2_init, 'W2')
b1 = theano.shared(b1_init, 'b1')
b2 = theano.shared(b2_init, 'b2')
#action function and softmax
tZ = relu(thX.dot(W1) + b1)
t_pY = T.nnet.softmax(tZ.dot(W2) + b2)
#cost function and predition function
cost = -(thT * T.log(t_pY)).sum() + reg * (W1 * W1).sum() + reg * (
W2 * W2).sum() + reg * (b1 * b1).sum() + reg * (b2 * b2).sum()
predition = T.argmax(t_pY, axis=1)
#training
update_b2 = b2 - learning_rate * T.grad(cost, b2)
update_W2 = W2 - learning_rate * T.grad(cost, W2)
update_b1 = b1 - learning_rate * T.grad(cost, b1)
update_W1 = W1 - learning_rate * T.grad(cost, W1)
train = theano.function(inputs=[thX, thT],
updates=[(W1, update_W1), (W2, update_W2),
(b1, update_b1), (b2, update_b2)])
get_prediction = theano.function(inputs=[thX, thT],
outputs=[cost, predition])
costs = []
for i in range(max_iter):
shuffle_X, shuffle_Y = shuffle(train_X, train_Y_ind)
for j in range(batch_num):
x = shuffle_X[j * batch_size:(j * batch_size + batch_size), :]
y = shuffle_Y[j * batch_size:(j * batch_size + batch_size), :]
train(x, y)
if j % print_period == 0:
cost, test_pY = get_prediction(test_X, test_Y_ind)
error = error_rate(test_pY, test_Y)
print("Cost / err at iteration i=%d, j=%d: %.3f / %.3f" %
(i, j, cost, error))
costs.append(cost)
plt.plot(costs)
plt.show()
def main():
max_iter = 10
print_period = 50
train_X, test_X, train_Y, test_Y = get_normalized_data()
reg = 0.01
train_Y_ind = indicator(train_Y)
test_Y_ind = indicator(test_Y)
N, D = train_X.shape
batch_size = 500
batch_num = N // batch_size
M = 300
K = 10
W1 = np.random.randn(D, M) / np.sqrt(D)
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
#SAVE INITIAL WEIGHT AND BIAS
W1_copy = W1.copy()
b1_copy = b1.copy()
W2_copy = W2.copy()
b2_copy = b2.copy()
#1st moment
mW1 = 0
mW2 = 0
mb1 = 0
mb2 = 0
#2nd moment
vW1 = 0
vW2 = 0
vb1 = 0
vb2 = 0
#hyperparams
learning_rate = 0.001
beta1 = 0.99
beta2 = 0.999
eps = 1e-8
#adam
lose_adam = []
error_adam = []
t = 1
for i in range(max_iter):
shuffle_X, shuffle_Y = shuffle(train_X, train_Y_ind)
for j in range(batch_num):
x = shuffle_X[j * batch_size:(j * batch_size + batch_size), :]
y = shuffle_Y[j * batch_size:(j * batch_size + batch_size), :]
pY, Z = forward(x, W1, W2, b1, b2)
#update gradient
gW2 = derivative_w2(Z, y, pY) + reg * W2
gb2 = derivative_b2(y, pY) + reg * b2
gW1 = derivative_w1(x, Z, y, pY, W2) + reg * W1
gb1 = derivative_b1(Z, y, pY, W2) + reg * b1
#update 1st moment
mW1 = beta1 * mW1 + (1 - beta1) * gW1
mW2 = beta1 * mW2 + (1 - beta1) * gW2
mb1 = beta1 * mb1 + (1 - beta1) * gb1
mb2 = beta1 * mb2 + (1 - beta1) * gb2
#update 2nd moment
vW1 = beta2 * vW1 + (1 - beta2) * gW1 * gW1
vW2 = beta2 * vW2 + (1 - beta2) * gW2 * gW2
vb1 = beta2 * vb1 + (1 - beta2) * gb1 * gb1
vb2 = beta2 * vb2 + (1 - beta2) * gb2 * gb2
#bias correction
correction_1 = 1 - beta1**t
correction_2 = 1 - beta2**t
mW1_hat = mW1 / correction_1
mW2_hat = mW2 / correction_1
mb1_hat = mb1 / correction_1
mb2_hat = mb2 / correction_1
vW1_hat = vW1 / correction_2
vW2_hat = vW2 / correction_2
vb1_hat = vb1 / correction_2
vb2_hat = vb2 / correction_2
#update t
t += 1
#update weight
W2 -= learning_rate * mW2_hat / np.sqrt(vW2_hat + eps)
b2 -= learning_rate * mb2_hat / np.sqrt(vb2_hat + eps)
b1 -= learning_rate * mb1_hat / np.sqrt(vb1_hat + eps)
W1 -= learning_rate * mW1_hat / np.sqrt(vW1_hat + eps)
if j % print_period == 0:
p_test, Z_test = forward(test_X, W1, W2, b1, b2)
l = cost(p_test, test_Y_ind)
e = error_rate(p_test, test_Y)
lose_adam.append(l)
error_adam.append(e)
print("cost at itertion i=%d, j=%d: %.6f" % (i, j, l))
print("error_rate: ", e)
p_final, z_final = forward(test_X, W1, W2, b1, b2)
print("final error_rate:", error_rate(p_final, test_Y))
#RMSprop with momentum
W1 = W1_copy.copy()
b1 = b1_copy.copy()
W2 = W2_copy.copy()
b2 = b2_copy.copy()
#hyperparams
learning_rate = 0.001
decay_rate = 0.999
mu = 0.9
eps = 1e-8
#rmsprop cache
cache_W1 = 1
cache_W2 = 1
cache_b1 = 1
cache_b2 = 1
#momentum
dW1 = 0
dW2 = 0
db1 = 0
db2 = 0
lose_rmsprop_m = []
error_rmsprop_m = []
t = 1
for i in range(max_iter):
shuffle_X, shuffle_Y = shuffle(train_X, train_Y_ind)
for j in range(batch_num):
x = shuffle_X[j * batch_size:(j * batch_size + batch_size), :]
y = shuffle_Y[j * batch_size:(j * batch_size + batch_size), :]
pY, Z = forward(x, W1, W2, b1, b2)
#udpate
gW2 = derivative_w2(Z, y, pY) + reg * W2
cache_W2 = decay_rate * cache_W2 + (1 - decay_rate) * gW2 * gW2
dW2 = mu * dW2 - (
1 - mu) * learning_rate * gW2 / np.sqrt(cache_W2 + eps)
W2 += dW2
gb2 = derivative_b2(y, pY) + reg * b2
cache_b2 = decay_rate * cache_b2 + (1 - decay_rate) * gb2 * gb2
db2 = mu * db2 - (
1 - mu) * learning_rate * gb2 / np.sqrt(cache_b2 + eps)
b2 += db2
gW1 = derivative_w1(x, Z, y, pY, W2) + reg * W1
cache_W1 = decay_rate * cache_W1 + (1 - decay_rate) * gW1 * gW1
dW1 = mu * dW1 - (
1 - mu) * learning_rate * gW1 / np.sqrt(cache_W1 + eps)
W1 += dW1
gb1 = derivative_b1(Z, y, pY, W2) + reg * b1
cache_b1 = decay_rate * cache_b1 + (1 - decay_rate) * gb1 * gb1
db1 = mu * db1 - (
1 - mu) * learning_rate * gb1 / np.sqrt(cache_b1 + eps)
b1 += db1
# #update cache
# cache_W1 = decay_rate * cache_W1 + (1-decay_rate)*gW1*gW1
# cache_W2 = decay_rate * cache_W2 + (1-decay_rate)*gW2*gW2
# cache_b1 = decay_rate * cache_b1 + (1-decay_rate)*gb1*gb1
# cache_b2 = decay_rate * cache_b2 + (1-decay_rate)*gb2*gb2
# #update momentum
# dW2 = mu*dW2 + (1-mu) * learning_rate * gW2 / (np.sqrt(cache_W2) + eps)
# db2 = mu*db2 + (1-mu) * learning_rate * gb2 / (np.sqrt(cache_b2) + eps)
# dW1 = mu*dW1 + (1-mu) * learning_rate * dW1 / (np.sqrt(cache_W1) + eps)
# db1 = mu*db1 + (1-mu) * learning_rate * db1 / (np.sqrt(cache_b1) + eps)
# #update weights
# W2 -= dW2
# b2 -= db2
# W1 -= dW1
# b1 -= db1
if j % print_period == 0:
p_test, Z_test = forward(test_X, W1, W2, b1, b2)
l = cost(p_test, test_Y_ind)
e = error_rate(p_test, test_Y)
lose_rmsprop_m.append(l)
error_rmsprop_m.append(e)
print("cost at itertion i=%d, j=%d: %.6f" % (i, j, l))
print("error_rate: ", e)
p_final, z_final = forward(test_X, W1, W2, b1, b2)
print("final error_rate:", error_rate(p_final, test_Y))
plt.plot(lose_adam, label="adam")
plt.plot(lose_rmsprop_m, label="rmsprop with momentum")
plt.legend()
plt.show()
def main():
max_iter = 20
print_period = 50
train_X, test_X, train_Y, test_Y = get_normalized_data()
learning_rate = 0.00004
reg = 0.01
train_Y_ind = indicator(train_Y)
test_Y_ind = indicator(test_Y)
N, D = train_X.shape
batch_size = 500
batch_num = N // batch_size
M = 300
K = 10
W1 = np.random.randn(D, M) / np.sqrt(D)
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
#SAVE INITIAL WEIGHT AND BIAS
W1_copy = W1.copy()
b1_copy = b1.copy()
W2_copy = W2.copy()
b2_copy = b2.copy()
#constant learning_rate
lose_constant = []
error_constant = []
for i in range(max_iter):
shuffle_X, shuffle_Y = shuffle(train_X, train_Y_ind)
for j in range(batch_num):
x = shuffle_X[j * batch_size:(j * batch_size + batch_size), :]
y = shuffle_Y[j * batch_size:(j * batch_size + batch_size), :]
pY, Z = forward(x, W1, W2, b1, b2)
W2 -= learning_rate * (derivative_w2(Z, y, pY) + reg * W2)
b2 -= learning_rate * (derivative_b2(y, pY) + reg * b2)
W1 -= learning_rate * (derivative_w1(x, Z, y, pY, W2) + reg * W1)
b1 -= learning_rate * (derivative_b1(Z, y, pY, W2) + reg * b1)
if j % print_period == 0:
p_test, Z_test = forward(test_X, W1, W2, b1, b2)
l = cost(p_test, test_Y_ind)
e = error_rate(p_test, test_Y)
lose_constant.append(l)
error_constant.append(e)
print("cost at itertion i=%d, j=%d: %.6f" % (i, j, l))
print("error_rate: ", e)
p_final, z_final = forward(test_X, W1, W2, b1, b2)
print("final error_rate:", error_rate(p_final, test_Y))
#RMSprop
W1 = W1_copy.copy()
b1 = b1_copy.copy()
W2 = W2_copy.copy()
b2 = b2_copy.copy()
learning_rate_0 = 0.001
lose_non_costant = []
error_non_constant = []
cache_W1 = 1
cache_W2 = 1
cache_b1 = 1
cache_b2 = 1
decay_rate = 0.999
eps = 1e-10
for i in range(max_iter):
shuffle_X, shuffle_Y = shuffle(train_X, train_Y_ind)
for j in range(batch_num):
x = shuffle_X[j * batch_size:(j * batch_size + batch_size), :]
y = shuffle_Y[j * batch_size:(j * batch_size + batch_size), :]
pY, Z = forward(x, W1, W2, b1, b2)
gW2 = derivative_w2(Z, y, pY) + reg * W2
cache_W2 = decay_rate * cache_W2 + (1 - decay_rate) * gW2 * gW2
W2 -= learning_rate_0 * gW2 / (np.sqrt(cache_W2) + eps)
gb2 = derivative_b2(y, pY) + reg * b2
cache_b2 = decay_rate * cache_b2 + (1 - decay_rate) * gb2 * gb2
b2 -= learning_rate_0 * gb2 / (np.sqrt(cache_b2) + eps)
gW1 = derivative_w1(x, Z, y, pY, W2) + reg * W1
cache_W1 = decay_rate * cache_W1 + (1 - decay_rate) * gW1 * gW1
W1 -= learning_rate_0 * gW1 / (np.sqrt(cache_W1) + eps)
gb1 = derivative_b1(Z, y, pY, W2) + reg * b1
cache_b1 = decay_rate * cache_b1 + (1 - decay_rate) * gb1 * gb1
b1 -= learning_rate_0 * gb1 / (np.sqrt(cache_b1) + eps)
if j % print_period == 0:
p_test, Z_test = forward(test_X, W1, W2, b1, b2)
l = cost(p_test, test_Y_ind)
e = error_rate(p_test, test_Y)
lose_non_costant.append(l)
error_non_constant.append(e)
print("cost at itertion i=%d, j=%d: %.6f" % (i, j, l))
print("error_rate: ", e)
p_final, z_final = forward(test_X, W1, W2, b1, b2)
print("final error_rate:", error_rate(p_final, test_Y))
plt.plot(lose_constant, label="batch")
plt.plot(lose_non_costant, label="non_constant")
plt.legend()
plt.show()
def main():
max_iter = 20
print_period = 50
train_X, test_X, train_Y, test_Y = get_normalized_data()
# learning_rate = 0.00004
reg = 0.01
train_Y_ind = indicator(train_Y)
test_Y_ind = indicator(test_Y)
N, D = train_X.shape
batch_size = 500
batch_num = N // batch_size
M = 300
K = 10
W1_init = np.random.randn(D, M) / np.sqrt(D)
b1_init = np.zeros(M)
W2_init = np.random.randn(M, K) / np.sqrt(M)
b2_init = np.zeros(K)
#1st moment
mW1_init = np.zeros((K, M))
mW2_init = np.zeros((M, K))
mb1_init = np.zeros((1, M))
mb2_init = np.zeros((1, K))
#2nd moment
vW1_init = np.zeros((M, M))
vW2_init = np.zeros((M, M))
vb1_init = np.zeros((M, M))
vb2_init = np.zeros((K, K))
#hyperparams
learning_rate = 0.001
beta1 = 0.99
beta2 = 0.999
eps = 1e-8
#other parameters
t_init = 1
#initialize theano variables
thX = T.matrix('X')
thT = T.matrix('T')
W1 = theano.shared(W1_init, 'W1')
W2 = theano.shared(W2_init, 'W2')
b1 = theano.shared(b1_init, 'b1')
b2 = theano.shared(b2_init, 'b2')
mW1 = theano.shared(mW1_init, 'mW1')
mW2 = theano.shared(mW2_init, 'mW2')
mb1 = theano.shared(mb1_init, 'mb1')
mb2 = theano.shared(mb2_init, 'mb2')
vW1 = theano.shared(vW1_init, 'vW1')
vW2 = theano.shared(vW2_init, 'vW2')
vb1 = theano.shared(vb1_init, 'vb1')
vb2 = theano.shared(vb2_init, 'vb2')
t = theano.shared(t_init, 't')
#action fuction
tZ = relu(thX.dot(W1) + b1)
t_pY = T.nnet.softmax(tZ.dot(W2) + b2)
#cost and prediction function
cost = -(thT * T.log(t_pY)).sum() + reg * ((W1 * W1).sum() +
(W2 * W2).sum() +
(b1 * b1).sum() +
(b2 * b2).sum())
prediction = T.argmax(t_pY, axis=1)
#trainning
#update gradient
gW2 = T.grad(cost, W2)
gb2 = T.grad(cost, b2)
gW1 = T.grad(cost, W1)
gb1 = T.grad(cost, b1)
#update 1st moment
update_mW1 = beta1 * mW1 + (1 - beta1) * gW1
update_mW2 = beta1 * mW2 + (1 - beta1) * gW2
update_mb1 = beta1 * mb1 + (1 - beta1) * gb1
update_mb2 = beta1 * mb2 + (1 - beta1) * gb2
#update 2nd moment
update_vW1 = beta2 * vW1 + (1 - beta2) * gW1 * gW1
update_vW2 = beta2 * vW2 + (1 - beta2) * gW2 * gW2
update_vb1 = beta2 * vb1 + (1 - beta2) * gb1 * gb1
update_vb2 = beta2 * vb2 + (1 - beta2) * gb2 * gb2
#bias correction
correction_1 = 1 - beta1**t
correction_2 = 1 - beta2**t
mW1_hat = mW1 / correction_1
mW2_hat = mW2 / correction_1
mb1_hat = mb1 / correction_1
mb2_hat = mb2 / correction_1
vW1_hat = vW1 / correction_2
vW2_hat = vW2 / correction_2
vb1_hat = vb1 / correction_2
vb2_hat = vb2 / correction_2
#update
update_t = t + 1
update_W2 = W2 - learning_rate * mW2_hat / T.sqrt(vW2_hat + eps)
update_b2 = b2 - learning_rate * mb2_hat / T.sqrt(vb2_hat + eps)
update_b1 = b1 - learning_rate * mb1_hat / T.sqrt(vb1_hat + eps)
update_W1 = W1 - learning_rate * mW1_hat / T.sqrt(vW1_hat + eps)
train = theano.function(inputs=[thX, thT],
updates=[(W1, update_W1), (W2, update_W2),
(b1, update_b1), (b2, update_b2),
(mW1, update_mW1), (mW2, update_mW2),
(mb1, update_mb1), (mb2, update_mb2),
(vW1, update_vW1), (vW2, update_vW2),
(vb1, update_vb1), (vb2, update_vb2),
(t, update_t)])
get_prediciton = theano.function(inputs=[thX, thT],
outputs=[cost, prediction])
costs = []
for i in range(max_iter):
shuffle_X, shuffle_Y = shuffle(train_X, train_Y_ind)
for j in range(batch_num):
x = shuffle_X[j * batch_size:(j * batch_size + batch_size), :]
y = shuffle_Y[j * batch_size:(j * batch_size + batch_size), :]
train(x, y)
if j % print_period == 0:
cost, test_pY = get_prediciton(test_X, test_Y_ind)
rror = error_rate(test_pY, test_Y)
print("Cost / err at iteration i=%d, j=%d: %.3f / %.3f" %
(i, j, cost, error))
costs.append(cost)
plt.plot(costs)
plt.show()
def main():
max_iter = 20
print_period = 50
train_X, test_X, train_Y, test_Y = get_normalized_data()
learning_rate = 0.00004
reg = 0.01
train_Y_ind = indicator(train_Y)
test_Y_ind = indicator(test_Y)
N, D = train_X.shape
batch_size = 500
batch_num = N // batch_size
M1 = 300
M2 = 100
K = 10
W1_init = np.random.randn(D, M1) / np.sqrt(D)
b1_init = np.zeros(M1)
W2_init = np.random.randn(M1, M2) / np.sqrt(M1)
b2_init = np.zeros(M2)
W3_init = np.random.randn(M2, K) / np.sqrt(M2)
b3_init = np.zeros(K)
#initialize tensorflow variables
X = tf.placeholder(tf.float32, shape=(None, D), name='X')
T = tf.placeholder(tf.float32, shape=(None, K), name='T')
W1 = tf.Variable(W1_init.astype(np.float32))
b1 = tf.Variable(b1_init.astype(np.float32))
W2 = tf.Variable(W2_init.astype(np.float32))
b2 = tf.Variable(b2_init.astype(np.float32))
W3 = tf.Variable(W3_init.astype(np.float32))
b3 = tf.Variable(b3_init.astype(np.float32))
#define model
Z1 = tf.nn.relu(tf.matmul(X, W1) + b1)
Z2 = tf.nn.relu(tf.matmul(Z1, W2) + b2)
Y_temp = tf.matmul(Z2, W3) + b3
cost = tf.reduce_sum(
tf.nn.softmax_cross_entropy_with_logits_v2(logits=Y_temp, labels=T))
train_op = tf.train.RMSPropOptimizer(learning_rate,
decay=0.99,
momentum=0.9).minimize(cost)
prediction_op = tf.argmax(Y_temp, axis=1)
costs = []
init = tf.global_variables_initializer()
with tf.Session() as session:
session.run(init)
for i in range(max_iter):
shuffle_X, shuffle_Y = shuffle(train_X, train_Y_ind)
for j in range(batch_num):
x = shuffle_X[j * batch_size:(j * batch_size + batch_size), :]
y = shuffle_Y[j * batch_size:(j * batch_size + batch_size), :]
session.run(train_op, feed_dict={X: x, T: y})
if j % print_period == 0:
test_cost = session.run(cost,
feed_dict={
X: test_X,
T: test_Y_ind
})
prediction = session.run(prediction_op,
feed_dict={X: test_X})
error = error_rate(prediction, test_Y)
print("Cost / err at iteration i=%d, j=%d: %.3f / %.3f" %
(i, j, test_cost, error))
costs.append(test_cost)
plt.plot(costs)
plt.show()
def main():
train_X, test_X, train_Y, test_Y = get_normalized_data()
model = ANN([500, 300], [0.8, 0.5, 0.5])
model.fit(train_X, train_Y, test_X, test_Y, show_fig=True)
def main():
max_iter = 20
print_period = 50
train_X, test_X, train_Y, test_Y = get_normalized_data()
learning_rate = 0.00004
reg = 0.01
train_Y_ind = indicator(train_Y)
test_Y_ind = indicator(test_Y)
N, D = train_X.shape
batch_size = 500
batch_num = N // batch_size
M = 300
K = 10
W1 = np.random.randn(D, M) / np.sqrt(D)
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
#SAVE INITIAL WEIGHT AND BIAS
W1_copy = W1.copy()
b1_copy = b1.copy()
W2_copy = W2.copy()
b2_copy = b2.copy()
#batch
loss_batch = []
error_batch =[]
for i in range(max_iter):
shuffle_X, shuffle_Y = shuffle(train_X, train_Y_ind)
for j in range(batch_num):
x = shuffle_X[j*batch_size : (j*batch_size+batch_size), :]
y = shuffle_Y[j*batch_size : (j*batch_size+batch_size), :]
pY, Z = forward(x, W1, W2, b1, b2)
W2 -= learning_rate * (derivative_w2(Z, y, pY) + reg*W2)
b2 -= learning_rate * (derivative_b2(y, pY) + reg*b2)
W1 -= learning_rate * (derivative_w1(x, Z, y, pY, W2) + reg*W1)
b1 -= learning_rate * (derivative_b1(Z, y, pY, W2) + reg*b1)
if j % print_period == 0:
p_test, Z_test = forward(test_X, W1, W2, b1, b2)
l = cost(p_test, test_Y_ind)
e = error_rate(p_test, test_Y)
loss_batch.append(l)
error_batch.append(e)
print("cost at itertion i=%d, j=%d: %.6f" % (i, j, l))
print("error_rate: ", e)
p_final, z_final = forward(test_X, W1, W2, b1, b2)
print("final error_rate:", error_rate(p_final, test_Y))
#momentum
W1 = W1_copy.copy()
b1 = b1_copy.copy()
W2 = W2_copy.copy()
b2 = b2_copy.copy()
lose_momentum = []
error_momentum = []
mu = 0.9
dW1 = 0
dW2 = 0
db1 = 0
db2 = 0
for i in range(max_iter):
shuffle_X, shuffle_Y = shuffle(train_X, train_Y_ind)
for j in range (batch_num):
x = shuffle_X[j*batch_size : (j*batch_size+batch_size), :]
y = shuffle_Y[j*batch_size : (j*batch_size+batch_size), :]
pY, Z = forward(x, W1, W2, b1, b2)
# print("overflow?")
gW2 = derivative_w2(Z, y, pY) + reg*W2
gb2 = derivative_b2(y, pY) + reg*b2
gW1 = derivative_w1(x, Z, y, pY, W2) + reg*W1
gb1 = derivative_b1(Z, y, pY, W2) + reg*b1
#UDPATE VELOCITIES
dW2 = mu*dW2 - learning_rate*gW2
db2 = mu*db2 - learning_rate*gb2
dW1 = mu*dW1 - learning_rate*gW1
db1 = mu*db1 - learning_rate*gb1
#UPDATE WEIGHT
W2 += dW2
b2 += db2
W1 += dW1
b1 += db1
if j % print_period == 0:
p_test, Z_test = forward(test_X, W1, W2, b1, b2)
l = cost(p_test, test_Y_ind)
e = error_rate(p_test, test_Y)
lose_momentum.append(l)
error_momentum.append(e)
print("cost at itertion i=%d, j=%d: %.6f" % (i, j, l))
print("error_rate: ", e)
p_final, z_final = forward(test_X, W1, W2, b1, b2)
print("final error_rate:", error_rate(p_final, test_Y))
#Nesterov momentum
W1 = W1_copy.copy()
b1 = b1_copy.copy()
W2 = W2_copy.copy()
b2 = b2_copy.copy()
lose_nesterov = []
error_nesterov = []
mu = 0.9
dW1 = 0
db1 = 0
dW2 = 0
db2 = 0
for i in range(max_iter):
shuffle_X, shuffle_Y = shuffle(test_X, test_Y_ind)
for j in range(batch_num):
x = shuffle_X[j*batch_size : (j*batch_size+batch_size), :]
y = shuffle_Y[j*batch_size : (j*batch_size+batch_size), :]
pY, Z = forward(x, W1, W2, b1, b2)
gW2 = derivative_w2(Z, y, pY) + reg*W2
gb2 = derivative_b2(y, pY) + reg*b2
gW1 = derivative_w1(x, Z, y, pY, W2) + reg*W1
gb1 = derivative_b1(Z, y, pY, W2) + reg*b1
#update velocities
dW2 = mu*dW2 - learning_rate*gW2
db2 = mu*db2 - learning_rate*db2
dW1 = mu*dW1 - learning_rate*gW1
db1 = mu*db1 - learning_rate*gb1
#update weight
W2 += mu*dW2 - learning_rate*gW2
b2 += mu*db2 - learning_rate*db2
W1 += mu*dW1 - learning_rate*gW1
b1 += mu*db1 - learning_rate*gb1
if j % print_period == 0:
p_test, Z_test = forward(test_X, W1, W2, b1, b2)
l = cost(p_test, test_Y_ind)
e = error_rate(p_test, test_Y)
lose_nesterov.append(l)
error_nesterov.append(e)
print("cost at itertion i=%d, j=%d: %.6f" % (i, j, l))
print("error_rate: ", e)
p_final, z_final = forward(test_X, W1, W2, b1, b2)
print("final error_rate:", error_rate(p_final, test_Y))
plt.plot(loss_batch, label="batch")
plt.plot(lose_momentum, label="momentum")
plt.plot(lose_nesterov, label="Nesterov")
plt.legend()
plt.show()