def main():
# compare 3 scenarios:
# 1. batch SGD
# 2. batch SGD with momentum
# 3. batch SGD with Nesterov momentum
max_iter = 20 # make it 30 for sigmoid
print_period = 50
Xtrain, Xtest, Ytrain, Ytest = get_normalized_data()
lr = 0.00004
reg = 0.01
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
batch_sz = 500
n_batches = N // batch_sz
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 weights
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
# 1. batch
losses_batch = []
errors_batch = []
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# print "first batch cost:", cost(pYbatch, Ybatch)
# updates
W2 -= lr * (derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
b2 -= lr * (derivative_b2(Ybatch, pYbatch) + reg * b2)
W1 -= lr * (derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) +
reg * W1)
b1 -= lr * (derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_batch.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_batch.append(e)
print("Error rate:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
# 2. batch with momentum
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
losses_momentum = []
errors_momentum = []
mu = 0.9
dW2 = 0
db2 = 0
dW1 = 0
db1 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# gradients
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg * W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg * b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1
# update velocities
dW2 = mu * dW2 - lr * gW2
db2 = mu * db2 - lr * gb2
dW1 = mu * dW1 - lr * gW1
db1 = mu * db1 - lr * gb1
# updates
W2 += dW2
b2 += db2
W1 += dW1
b1 += db1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_momentum.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_momentum.append(e)
print("Error rate:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
# 3. batch with Nesterov momentum
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
losses_nesterov = []
errors_nesterov = []
mu = 0.9
vW2 = 0
vb2 = 0
vW1 = 0
vb1 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg * W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg * b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1
# v update
vW2 = mu * vW2 - lr * gW2
vb2 = mu * vb2 - lr * gb2
vW1 = mu * vW1 - lr * gW1
vb1 = mu * vb1 - lr * gb1
# param update
W2 += mu * vW2 - lr * gW2
b2 += mu * vb2 - lr * gb2
W1 += mu * vW1 - lr * gW1
b1 += mu * vb1 - lr * gb1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_nesterov.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_nesterov.append(e)
print("Error rate:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
plt.plot(losses_batch, label="batch")
plt.plot(losses_momentum, label="momentum")
plt.plot(losses_nesterov, label="nesterov")
plt.legend()
plt.show()
def main():
max_iter = 10
print_period = 40
Xtrain, Xtest, Ytrain, Ytest = get_normalized_data()
Ytrain_ind = y2indicator(Ytrain) # Target of train data
Ytest_ind = y2indicator(Ytest) # Target of test data
N, D = Xtrain.shape
M = 300
K = 10
np.random.seed(123)
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)
batch_sz = 500
n_batches = N // batch_sz # 82
# save initial weights
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
lr = 0.001
reg = 0.01
# 1. RMSProp + Momemtum
decay_rate = 0.999
eps = 1e-8
mu = 0.9
# RMSProp cache
cache_W2 = 1
cache_b2 = 1
cache_W1 = 1
cache_b1 = 1
# momentum
dW2 = 0
db2 = 0
dW1 = 0
db1 = 0
losses_rms = []
errors_rms = []
for i in range(max_iter):
# Xtrain, Ytrain_ind = shuffle(Xtrain, Ytrain_ind)
for j in range(n_batches):
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),] # Target of each batch
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
## 這邊updata momentum的形式，不是原始定義，而是模仿adam的 moment1
## 可以當成沒有使用 Bias correction 的 adam
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg*W2
cache_W2 = decay_rate*cache_W2 + (1 - decay_rate)*gW2*gW2
dW2 = mu*dW2 + (1 - mu) * lr * gW2 / (np.sqrt(cache_W2) + eps)
W2 -= dW2
gb2 = derivative_b2(Ybatch, pYbatch) + reg*b2
cache_b2 = decay_rate*cache_b2 + (1 - decay_rate)*gb2*gb2
db2 = mu*db2 + (1 - mu) * lr * gb2 / (np.sqrt(cache_b2) + eps)
b2 -= db2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1
cache_W1 = decay_rate*cache_W1 + (1 - decay_rate)*gW1*gW1
dW1 = mu*dW1 + (1 - mu) * lr * gW1 / (np.sqrt(cache_W1) + eps)
W1 -= dW1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1
cache_b1 = decay_rate*cache_b1 + (1 - decay_rate)*gb1*gb1
db1 = mu*db1 + (1 - mu)* lr * gb1 / (np.sqrt(cache_b1) + eps)
b1 -= db1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_rms.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_rms.append(e)
print("Error rate:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
# 2. Adam
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
beta1 = 0.9 # 0.999 # 這兩個值調一下 就會發生很大變化的樣子， 也就是說參數調教超重要的阿
beta2 = 0.999 # 0.99
eps = 1e-8
t = 1
m_W2 = 0
m_b2 = 0
m_W1 = 0
m_b1 = 0
v_W2 = 0
v_b2 = 0
v_W1 = 0
v_b1 = 0
losses_adam = []
errors_adam = []
for i in range(max_iter):
# Xtrain, Ytrain_ind = shuffle(Xtrain, Ytrain_ind)
for j in range(n_batches):
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),] # Target of each batch
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# gradient
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg*W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg*b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1
# new m
m_W2 = beta1*m_W2 + (1 - beta1)*gW2
m_b2 = beta1*m_b2 + (1 - beta1)*gb2
m_W1 = beta1*m_W1 + (1 - beta1)*gW1
m_b1 = beta1*m_b1 + (1 - beta1)*gb1
# new v
v_W2 = beta2*v_W2 + (1 - beta2)*gW2*gW2
v_b2 = beta2*v_b2 + (1 - beta2)*gb2*gb2
v_W1 = beta2*v_W1 + (1 - beta2)*gW1*gW1
v_b1 = beta2*v_b1 + (1 - beta2)*gb1*gb1
# m_hat get from bias correction
m_W2_hat = m_W2 / (1 - beta1**t)
m_b2_hat = m_b2 / (1 - beta1**t)
m_W1_hat = m_W1 / (1 - beta1**t)
m_b1_hat = m_b1 / (1 - beta1**t)
# v_hat get from bias correction
v_W2_hat = v_W2 / (1 - beta2**t)
v_b2_hat = v_b2 / (1 - beta2**t)
v_W1_hat = v_W1 / (1 - beta2**t)
v_b1_hat = v_b1 / (1 - beta2**t)
# update
W2 -= lr * m_W2_hat / np.sqrt(v_W2_hat + eps)
b2 -= lr * m_b2_hat / np.sqrt(v_b2_hat + eps)
W1 -= lr * m_W1_hat / np.sqrt(v_W1_hat + eps)
b1 -= lr * m_b1_hat / np.sqrt(v_b1_hat + eps)
t += 1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_adam.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_adam.append(e)
print("Error rate:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
plt.plot(losses_rms, label='RMSprop + Momentun')
plt.plot(losses_adam, label='Adam')
plt.legend()
plt.show()
def main():
# compare 3 scenarios:
# 1. batch SGD
# 2. batch SGD with momentum
# 3. batch SGD with Nesterov momentum
max_iter = 20 # make it 30 for sigmoid
print_period = 10
X, Y = get_normalized_data()
lr = 0.00004
reg = 0.01
Xtrain = X[:-1000,]
Ytrain = Y[:-1000]
Xtest = X[-1000:,]
Ytest = Y[-1000:]
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
batch_sz = 500
n_batches = N / batch_sz
M = 300
K = 10
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
# 1. batch
# cost = -16
LL_batch = []
CR_batch = []
for i in xrange(max_iter):
for j in xrange(n_batches):
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# print "first batch cost:", cost(pYbatch, Ybatch)
# updates
W2 -= lr*(derivative_w2(Z, Ybatch, pYbatch) + reg*W2)
b2 -= lr*(derivative_b2(Ybatch, pYbatch) + reg*b2)
W1 -= lr*(derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1)
b1 -= lr*(derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1)
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_batch.append(ll)
print "Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll)
err = error_rate(pY, Ytest)
CR_batch.append(err)
print "Error rate:", err
pY, _ = forward(Xtest, W1, b1, W2, b2)
print "Final error rate:", error_rate(pY, Ytest)
# 2. batch with momentum
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
LL_momentum = []
CR_momentum = []
mu = 0.9
dW2 = 0
db2 = 0
dW1 = 0
db1 = 0
for i in xrange(max_iter):
for j in xrange(n_batches):
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
dW2 = mu*dW2 - lr*(derivative_w2(Z, Ybatch, pYbatch) + reg*W2)
W2 += dW2
db2 = mu*db2 - lr*(derivative_b2(Ybatch, pYbatch) + reg*b2)
b2 += db2
dW1 = mu*dW1 - lr*(derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1)
W1 += dW1
db1 = mu*db1 - lr*(derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1)
b1 += db1
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_momentum.append(ll)
print "Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll)
err = error_rate(pY, Ytest)
CR_momentum.append(err)
print "Error rate:", err
pY, _ = forward(Xtest, W1, b1, W2, b2)
print "Final error rate:", error_rate(pY, Ytest)
# 3. batch with Nesterov momentum
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
LL_nest = []
CR_nest = []
mu = 0.9
dW2 = 0
db2 = 0
dW1 = 0
db1 = 0
for i in xrange(max_iter):
for j in xrange(n_batches):
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
dW2 = mu*mu*dW2 - (1 + mu)*lr*(derivative_w2(Z, Ybatch, pYbatch) + reg*W2)
W2 += dW2
db2 = mu*mu*db2 - (1 + mu)*lr*(derivative_b2(Ybatch, pYbatch) + reg*b2)
b2 += db2
dW1 = mu*mu*dW1 - (1 + mu)*lr*(derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1)
W1 += dW1
db1 = mu*mu*db1 - (1 + mu)*lr*(derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1)
b1 += db1
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_nest.append(ll)
print "Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll)
err = error_rate(pY, Ytest)
CR_nest.append(err)
print "Error rate:", err
pY, _ = forward(Xtest, W1, b1, W2, b2)
print "Final error rate:", error_rate(pY, Ytest)
plt.plot(LL_batch, label="batch")
plt.plot(LL_momentum, label="momentum")
plt.plot(LL_nest, label="nesterov")
plt.legend()
plt.show()
def main():
max_iter = 20 # make it 30 for sigmoid
print_period = 10
X, Y = get_normalized_data()
lr = 0.00004
reg = 0.01
Xtrain = X[:-1000, ]
Ytrain = Y[:-1000]
Xtest = X[-1000:, ]
Ytest = Y[-1000:]
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
batch_sz = 500
n_batches = int(N / batch_sz)
M = 300
K = 10
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
# 1. const
# cost = -16
LL_batch = []
CR_batch = []
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# print "first batch cost:", cost(pYbatch, Ybatch)
# updates
W2 -= lr * (derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
b2 -= lr * (derivative_b2(Ybatch, pYbatch) + reg * b2)
W1 -= lr * (derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) +
reg * W1)
b1 -= lr * (derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_batch.append(ll)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll))
err = error_rate(pY, Ytest)
CR_batch.append(err)
print("Error rate:", err)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
# 2. RMSprop
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
LL_rms = []
CR_rms = []
lr0 = 0.001 # if you set this too high you'll get NaN!
cache_W2 = 0
cache_b2 = 0
cache_W1 = 0
cache_b1 = 0
decay_rate = 0.999
eps = 0.0000000001
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# print "first batch cost:", cost(pYbatch, Ybatch)
# updates
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg * W2
cache_W2 = decay_rate * cache_W2 + (1 - decay_rate) * gW2 * gW2
W2 -= lr0 * gW2 / (np.sqrt(cache_W2) + eps)
gb2 = derivative_b2(Ybatch, pYbatch) + reg * b2
cache_b2 = decay_rate * cache_b2 + (1 - decay_rate) * gb2 * gb2
b2 -= lr0 * gb2 / (np.sqrt(cache_b2) + eps)
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1
cache_W1 = decay_rate * cache_W1 + (1 - decay_rate) * gW1 * gW1
W1 -= lr0 * gW1 / (np.sqrt(cache_W1) + eps)
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1
cache_b1 = decay_rate * cache_b1 + (1 - decay_rate) * gb1 * gb1
b1 -= lr0 * gb1 / (np.sqrt(cache_b1) + eps)
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_rms.append(ll)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll))
err = error_rate(pY, Ytest)
CR_rms.append(err)
print("Error rate:", err)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
plt.plot(LL_batch, label='const')
plt.plot(LL_rms, label='rms')
plt.legend()
plt.show()
def main():
# compare 3 scenarios:
# 1. batch SGD
# 2. batch SGD with momentum
'''
# steps of training a model
# 0. get data
# 1. function --> forwrad --> OK
# 2. loss --> cost --> ok
# 3. solver --> gradient descent
'''
max_iter = 20 # make it 30 for sigmoid
print_period = 50
Xtrain, Xtest, Ytrain, Ytest = get_normalized_data()
lr = 0.00004
reg = 0.01
Ytrain_ind = y2indicator(Ytrain) # Target of train data
Ytest_ind = y2indicator(Ytest) # Target of test data
N, D = Xtrain.shape
batch_sz = 500
n_batches = N // batch_sz
M = 300
K = 10
np.random.seed(42)
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)
'''
initial weight 分母除上np.sqrt(D)對cost非常有幫助
1. 如果不除這個東東，initial weight 會太大，將造成以下後果
1.1 計算forward()時，通過sigmoid中的np.exp(-( X.dot(W1) + b1 ))，一開始很可能會出現太大數字(overflow encountered 數據溢出)，
溢出代表該數字物件的型別無法承載這麼大數字，會報錯，但code還是能繼續跑，因為sigmoid的值在0~1之間
1.2 如果是通過relu，輸出值可能會是一極大值
之後後再經過expA = np.exp(A)，大概首輪epoch中的第二個batch計算時，就會得到無限大爆掉了
1.3 結論: activation = relu時， initial weight要夠小
2. 除上一個極大值500 ( 約np.sqrt(D)的20倍 )，在update weight with momentum的實驗中，
最後一個epoch的cost = 106.49
3. 除 np.sqrt(D)，在update weight with momentum的實驗中，
最後一個epoch的cost = 119.005
4. 除上一個極大值5000，在update weight with momentum的實驗中，
最後一個epoch的cost = 160.68
5. 其他參考書上說，大部分情況直接無腦除上100即可以得到很好的訓練成果
'''
# save initial weights
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
# 1. batch SGD
losses_batch = []
errors_batch = []
for i in range(max_iter):
# Xtrain, Ytrain_ind = shuffle(Xtrain, Ytrain_ind)
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz),
] # Target of each batch
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# print "first batch cost:", cost(pYbatch, Ybatch)
# updates
W2 -= lr * (derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
b2 -= lr * (derivative_b2(Ybatch, pYbatch) + reg * b2)
W1 -= lr * (derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) +
reg * W1)
b1 -= lr * (derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_batch.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_batch.append(e)
print("Error rate:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
# 2. batch with momentum
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
losses_momentum = []
errors_momentum = []
mu = 0.9 # momentu的係數，大多數用0.9 就已經足夠好了
dW2 = 0
db2 = 0
dW1 = 0
db1 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# gradients
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg * W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg * b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1
# update velocities
dW2 = mu * dW2 - lr * gW2
db2 = mu * db2 - lr * gb2
dW1 = mu * dW1 - lr * gW1
db1 = mu * db1 - lr * gb1
# updates
W2 += dW2
b2 += db2
W1 += dW1
b1 += db1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_momentum.append(l)
print('Cost at iteration i=%d, j=%d : %.6f' % (i, j, l))
e = error_rate(pY, Ytest)
errors_momentum.append(e)
print('Error rate:', e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print('Fianl error rate:', error_rate(pY, Ytest))
plt.plot(losses_batch, label='batch')
plt.plot(losses_momentum, label="momentum")
plt.legend()
plt.show()
def main():
# compare 5 scenarios:
# 1. batch SGD with constant learning rate
# 2. batch SGD with RMSProp
# 3. batch SGD with AdaGrad
# 4. batch SGD with exponential decay
np.random.seed(2)
max_iter = 20
print_period = 10
X, Y = get_normalized_data()
lr = 0.00004
reg = 0.01
Xtrain, Ytrain = X[:-1000, :], Y[:-1000]
Xtest, Ytest = X[-1000:, :], Y[-1000:]
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
M = 300 # number of hidden layer units
K = len(set(Ytrain))
batch_size = 500
n_batches = N // batch_size
# randomly initialize weights:
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 weights:
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
# 1. batch SGD with constant learning rate:
LL_batch = []
CR_batch = []
t0 = datetime.now()
print('\nperforming batch SGD with constant learning rate...')
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_size:(j + 1) * batch_size, :]
Ybatch = Ytrain_ind[j * batch_size:(j + 1) * batch_size, :]
p_Ybatch, Z = forward(Xbatch, W1, b1, W2, b2)
#print(Z.shape, p_Ybatch.shape, Ybatch.shape)
#print('First batch cost:', cost(p_Ybatch, Ybatch))
# updates:
W2 -= lr * (derivative_W2(Z, Ybatch, p_Ybatch) + reg * W2)
b2 -= lr * (derivative_b2(Ybatch, p_Ybatch) + reg * b2)
W1 -= lr * (derivative_W1(Xbatch, Z, Ybatch, p_Ybatch, W2) +
reg * W1)
b1 -= lr * (derivative_b1(Z, Ybatch, p_Ybatch, W2) + reg * b1)
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
#print('pY:', pY)
ll = cost(pY, Ytest_ind)
LL_batch.append(ll)
print('\ni: %d, j: %d, cost: %.6f' % (i, j, ll))
error = error_rate(pY, Ytest)
CR_batch.append(error)
print('error rate:', error)
dt1 = datetime.now() - t0
pY, _ = forward(Xtest, W1, b1, W2, b2)
final_err1 = error_rate(pY, Ytest)
# plot the cost
#plt.plot(LL_batch)
#plt.title('Cost for batch GD with const lr')
#plt.show()
# 2. batch GD with RMSProp:
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
LL_RMSProp = []
CR_RMSProp = []
lr0 = 0.001 # initial learning rate
cache_W2 = 1
cache_b2 = 1
cache_W1 = 1
cache_b1 = 1
decay = 0.999
eps = 10e-10
t0 = datetime.now()
print('\nperforming batch SGD with RMSProp...')
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_size:(j + 1) * batch_size, :]
Ybatch = Ytrain_ind[j * batch_size:(j + 1) * batch_size, :]
p_Ybatch, Z = forward(Xbatch, W1, b1, W2, b2)
#print(Z.shape, p_Ybatch.shape, Ybatch.shape)
#print('First batch cost:', cost(p_Ybatch, Ybatch))
# updates:
gW2 = (derivative_W2(Z, Ybatch, p_Ybatch) + reg * W2)
cache_W2 = decay * cache_W2 + (1 - decay) * gW2 * gW2
W2 -= lr0 * gW2 / np.sqrt(cache_W2 + eps)
gb2 = (derivative_b2(Ybatch, p_Ybatch) + reg * b2)
cache_b2 = decay * cache_b2 + (1 - decay) * gb2 * gb2
b2 -= lr0 * gb2 / np.sqrt(cache_b2 + eps)
gW1 = (derivative_W1(Xbatch, Z, Ybatch, p_Ybatch, W2) + reg * W1)
cache_W1 = decay * cache_W1 + (1 - decay) * gW1 * gW1
W1 -= lr0 * gW1 / np.sqrt(cache_W1 + eps)
gb1 = (derivative_b1(Z, Ybatch, p_Ybatch, W2) + reg * b1)
cache_b1 = decay * cache_b1 + (1 - decay) * gb1 * gb1
b1 -= lr0 * gb1 / np.sqrt(cache_b1 + eps)
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
#print('pY:', pY)
ll = cost(pY, Ytest_ind)
LL_RMSProp.append(ll)
print('\ni: %d, j: %d, cost: %.6f' % (i, j, ll))
error = error_rate(pY, Ytest)
CR_RMSProp.append(error)
print('error rate:', error)
dt2 = datetime.now() - t0
pY, _ = forward(Xtest, W1, b1, W2, b2)
final_err2 = error_rate(pY, Ytest)
# plot the cost
#plt.plot(LL_RMSProp)
#plt.title('Cost for batch SGD with RMSProp')
#plt.show()
# 3. batch SGD with AdaGrad:
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
LL_AdaGrad = []
CR_AdaGrad = []
lr0 = 0.01 # initial learning rate
cache_W2 = 1
cache_b2 = 1
cache_W1 = 1
cache_b1 = 1
eps = 10e-10
t0 = datetime.now()
print('\nperforming batch SGD with AdaGrad...')
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_size:(j + 1) * batch_size, :]
Ybatch = Ytrain_ind[j * batch_size:(j + 1) * batch_size, :]
p_Ybatch, Z = forward(Xbatch, W1, b1, W2, b2)
#print(Z.shape, p_Ybatch.shape, Ybatch.shape)
#print('First batch cost:', cost(p_Ybatch, Ybatch))
# updates:
gW2 = (derivative_W2(Z, Ybatch, p_Ybatch) + reg * W2)
cache_W2 = cache_W2 + gW2 * gW2
W2 -= lr0 * gW2 / np.sqrt(cache_W2 + eps)
gb2 = (derivative_b2(Ybatch, p_Ybatch) + reg * b2)
cache_b2 = cache_b2 + gb2 * gb2
b2 -= lr0 * gb2 / np.sqrt(cache_b2 + eps)
gW1 = (derivative_W1(Xbatch, Z, Ybatch, p_Ybatch, W2) + reg * W1)
cache_W1 = cache_W1 + gW1 * gW1
W1 -= lr0 * gW1 / np.sqrt(cache_W1 + eps)
gb1 = (derivative_b1(Z, Ybatch, p_Ybatch, W2) + reg * b1)
cache_b1 = cache_b1 + gb1 * gb1
b1 -= lr0 * gb1 / np.sqrt(cache_b1 + eps)
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
#print('pY:', pY)
ll = cost(pY, Ytest_ind)
LL_AdaGrad.append(ll)
print('\ni: %d, j: %d, cost: %.6f' % (i, j, ll))
error = error_rate(pY, Ytest)
CR_AdaGrad.append(error)
print('error rate:', error)
dt3 = datetime.now() - t0
pY, _ = forward(Xtest, W1, b1, W2, b2)
final_err3 = error_rate(pY, Ytest)
# plot the cost
#plt.plot(LL_AdaGrad)
#plt.title('Cost for batch SGD with AdaGrad')
#plt.show()
'''
# 4. batch SGD with exponential decay:
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
LL_exp = []
CR_exp = []
lr0 = 0.0004 # initial learning rate
k = 1e-7
t = 0 # initial log
lr = lr0
t0 = datetime.now()
print('\nperforming batch SGD with lr exponential decay...')
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j*batch_size:(j+1)*batch_size, :]
Ybatch = Ytrain_ind[j*batch_size:(j+1)*batch_size, :]
p_Ybatch, Z = forward(Xbatch, W1, b1, W2, b2)
#print(Z.shape, p_Ybatch.shape, Ybatch.shape)
#print('First batch cost:', cost(p_Ybatch, Ybatch))
# updates:
gW2 = (derivative_W2(Z, Ybatch, p_Ybatch) + reg*W2)
W2 -= lr*gW2
gb2 = (derivative_b2(Ybatch, p_Ybatch) + reg*b2)
b2 -= lr*gb2
gW1 = (derivative_W1(Xbatch, Z, Ybatch, p_Ybatch, W2) + reg*W1)
W1 -= lr*gW1
gb1 = (derivative_b1(Z, Ybatch, p_Ybatch, W2) + reg*b1)
b1 -= lr*gb1
# decrease the learning rate
lr = lr0 * np.exp(-k*t)
t += 1
if j % print_period == 0:
print('current learning rate:', lr)
pY, _ = forward(Xtest, W1, b1, W2, b2)
#print('pY:', pY)
ll = cost(pY, Ytest_ind)
LL_exp.append(ll)
print('\ni: %d, j: %d, cost: %.6f' % (i, j, ll))
error = error_rate(pY, Ytest)
CR_exp.append(error)
print('error rate:', error)
dt4 = datetime.now() - t0
pY, _ = forward(Xtest, W1, b1, W2, b2)
print('\nFinal error rate:', error_rate(pY, Ytest))
print('Elapsed time for batch SGD with lr exponential decay:', dt4)
# plot the cost
#plt.plot(LL_exp)
#plt.title('Cost for batch SGD with lr exponential decay')
#plt.show()
'''
print('\nBatch SGD with constant learning rate:')
print('final error rate:', final_err1)
print('elapsed time:', dt1)
print('\nBatch SGD with RMSProp:')
print('final error rate:', final_err2)
print('elapsed time:', dt2)
print('\nBatch SGD with AdaGrad:')
print('final error rate:', final_err3)
print('elapsed time:', dt3)
# plot the costs together:
plt.plot(LL_batch, label='const_lr')
plt.plot(LL_RMSProp, label='RMSProp')
plt.plot(LL_AdaGrad, label='AdaGrad')
#plt.plot(LL_exp, label='lr_exp_decay')
plt.legend()
plt.show()
def main():
# compare 3:
# 1. batch SGD
# 2. batch SGD with momentum
# 3. batch SGD with Nesterov momentum
# all with L2 regularization
X, Y = get_normalized_data()
Xtrain = X[:-1000, ]
Ytrain = Y[:-1000]
Xtest = X[-1000:, ]
Ytest = Y[-1000:]
N, D = Xtrain.shape
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
M = 300
K = 10
######################IMPORTANETE PARAMETERE ####################
t = 1 # !!!!!!!!!!!!!!!!
###############################################################
epochs = 20
print_period = 10
lr0 = 0.001
reg = 0.01
epsilon = 1e-8 # is it the same as 10e-8
beta1 = 0.9 # mu = 0.9
beta2 = 0.999 # decay = 0.999
batch_size = 500
number_batches = int(N // batch_size)
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
tr_costs_momentum = []
errors_batch_momentum = []
losses_test_momentum = []
# momentum coeficient
mW2 = 0
mW1 = 0
mb2 = 0
mb1 = 0
vW1 = 0
vW2 = 0
vb1 = 0
vb2 = 0
mW2_hat = 0
mW1_hat = 0
mb2_hat = 0
mb1_hat = 0
vW1_hat = 0
vW2_hat = 0
vb1_hat = 0
vb2_hat = 0
for epoch in range(epochs):
for j in range(number_batches):
xtr = Xtrain[j * batch_size:(j * batch_size + batch_size), :]
ytr = Ytrain_ind[j * batch_size:(j * batch_size + batch_size), :]
ytr_pred, z_tr = forward(xtr, W1, b1, W2, b2)
# gradients
gW2 = derivative_w2(z_tr, ytr, ytr_pred) + reg * W2
gb2 = derivative_b2(ytr, ytr_pred) + reg * b2
gW1 = derivative_w1(xtr, z_tr, ytr, ytr_pred, W2) + reg * W1
gb1 = derivative_b1(z_tr, ytr, ytr_pred, W2) + reg * b1
# update momentum
mW2 = beta1 * mW2 + (1 - beta1) * gW2
mW1 = beta1 * mW1 + (1 - beta1) * gW1
mb2 = beta1 * mb2 + (1 - beta1) * gb2
mb1 = beta1 * mb1 + (1 - beta1) * gb1
# update velocity
vW2 = beta2 * vW2 + (1 - beta2) * gW2 * gW2
vb2 = beta2 * vb2 + (1 - beta2) * gb2 * gb2
vW1 = beta2 * vW1 + (1 - beta2) * gW1 * gW1
vb1 = beta2 * vb1 + (1 - beta2) * gb1 * gb1
# bias correction
correction1 = (1 - beta1**t)
mW2_hat = mW2 / correction1
mW1_hat = mW1 / correction1
mb2_hat = mb2 / correction1
mb1_hat = mb1 / correction1
correction2 = (1 - beta2**t)
vW2_hat = vW2 / correction2
vW1_hat = vW1 / correction2
vb2_hat = vb2 / correction2
vb1_hat = vb1 / correction2
# update t !!!!!!!
t += 1
# update
W2 -= lr0 * (mW2_hat / np.sqrt(vW2_hat + epsilon))
W1 -= lr0 * (mW1_hat / np.sqrt(vW1_hat + epsilon))
b2 -= lr0 * (mb2_hat / np.sqrt(vb2_hat + epsilon))
b1 -= lr0 * (mb1_hat / np.sqrt(vb1_hat + epsilon))
if j % print_period == 0:
yte_pred, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(yte_pred, Ytest_ind)
losses_test_momentum.append(l)
print("test set Cost at iteration epoch=%d, j=%d: %.6f" %
(epoch, j, l))
e = error_rate(yte_pred, Ytest)
errors_batch_momentum.append(e)
print("Error rate:", e)
ctr = cost(ytr_pred, ytr)
print("traning set cost", ctr)
tr_costs_momentum.append(ctr)
pY, _ = forward(Xtest, W1, b1, W2, b2)
#plt.plot(tr_costs_momentum, label='tr_costs momentum')
plt.plot(losses_test_momentum, label='losses_test momentum RMS')
#plt.plot(errors_batch, label='errors_batch')
# plt.show()
# print("tr_costs", errors_batch_momentum)
print("Final error rate:", error_rate(pY, Ytest))
plt.legend()
plt.show()
def main():
dobatch = False
dobatchwithmomentum = True
dobatchwithnesterovmomentum = True
max_iter = 20 # make it 30 for sigmoid
print_period = 50
Xtrain, Xtest, Ytrain, Ytest = get_normalized_data()
lr = 0.00004
reg = 0.01
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
batch_sz = 500
n_batches = N // batch_sz
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 weights
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
# batch
#cost = -16
if dobatch:
losses_batch = []
errors_batch = []
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
W2 -= lr * (derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
b2 -= lr * (derivative_b2(Ybatch, pYbatch) + reg * b2)
W1 -= lr * (derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) +
reg * W1)
b1 -= lr * (derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_batch.append(l)
print("cost at iter i %d, j %d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_batch.append(e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("final error rate: ", error_rate(pY, Ytest))
print()
# batch with momentum
if dobatchwithmomentum:
print("momentum")
W1 = W1_0.copy
b1 = b1_0.copy
W2 = W2_0.copy
b2 = b2_0.copy
losses_momentum = []
errors_momentum = []
mu = 0.9
dW2 = 0
db2 = 0
dW1 = 0
db1 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg * W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg * b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1
dW2 = mu * dW2 - lr * gW2
db2 = mu * db2 - lr * gb2
dW1 = mu * dW1 - lr * gW1
db1 = mu * db1 - lr * gb1
W2 += dW2
b2 += db2
W1 += dW1
b1 += db1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_momentum.append(l)
print("cost at iter i %d, j %d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_momentum.append(e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("final error rate: ", error_rate(pY, Ytest))
print()
# Nesterov momentum
if dobatchwithnesterovmomentum:
W1 = W1_0.copy
b1 = b1_0.copy
W2 = W2_0.copy
b2 = b2_0.copy
losses_nesterov = []
errors_nesterov = []
mu = 0.9
vW2 = 0
vb2 = 0
vW1 = 0
vb1 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg * W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg * b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1
vW2 = mu * vW2 - lr * gW2
vb2 = mu * vb2 - lr * gb2
vW1 = mu * vW1 - lr * gW1
vb1 = mu * vb1 - lr * gb1
W2 += mu * vW2 - lr * gW2
b2 += mu * vb2 - lr * gb2
W1 += mu * vW1 - lr * gW1
b1 += mu * vb1 - lr * gb1
W2 += dW2
b2 += db2
W1 += dW1
b1 += db1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_nesterov.append(l)
print("cost at iter i %d, j %d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_nesterov.append(e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("final error rate: ", error_rate(pY, Ytest))
print()
plt.plot(losses_batch, label="batch")
plt.plot(losses_momentum, label="momentum")
plt.plot(losses_nesterov, label="nesterov")
plt.legend()
plt.show()
def main():
# compare 3:
# 1. batch SGD
# 2. batch SGD with momentum
# 3. batch SGD with Nesterov momentum
# all with L2 regularization
X, Y = get_normalized_data()
Xtrain = X[:-1000, ]
Ytrain = Y[:-1000]
Xtest = X[-1000:, ]
Ytest = Y[-1000:]
N, D = Xtrain.shape
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
M = 300
K = 10
max_iter = 20
epochs = 20
print_period = 10
lr0 = 0.0004
reg = 0.01
epsilon = 10e-10
decay = 0.999
batch_size = 500
number_batches = int(N // batch_size)
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
cache_W2 = 1
cache_W1 = 1
cache_b2 = 1
cache_b1 = 1
tr_costs = []
errors_batch = []
losses_test = []
# 1. Just grad & RMSprop
# 1.
for epoch in range(epochs):
for j in range(number_batches):
xtr = Xtrain[j * batch_size:(j * batch_size + batch_size), :]
ytr = Ytrain_ind[j * batch_size:(j * batch_size + batch_size), :]
ytr_pred, z_tr = forward(xtr, W1, b1, W2, b2)
# gradients
gW2 = derivative_w2(z_tr, ytr, ytr_pred) + reg * W2
gb2 = derivative_b2(ytr, ytr_pred) + reg * b2
gW1 = derivative_w1(xtr, z_tr, ytr, ytr_pred, W2) + reg * W1
gb1 = derivative_b1(z_tr, ytr, ytr_pred, W2) + reg * b1
# # AdaGrad
# cache_W2 += derivative_w2(z_tr, ytr, ytr_pred) * derivative_w2(z_tr, ytr, ytr_pred)
# cache_W1 += derivative_w1(xtr, z_tr, ytr, ytr_pred, W2) * derivative_w1(xtr, z_tr, ytr, ytr_pred, W2)
# cache_b2 += derivative_b2(ytr, ytr_pred) * derivative_b2(ytr, ytr_pred)
# cache_b1 += derivative_b1(z_tr, ytr, ytr_pred, W2) * derivative_b1(z_tr, ytr, ytr_pred, W2)
# RMSProp
cache_W2 += decay * cache_W2 + (1 - decay) * gW2 * gW2
cache_W1 += decay * cache_W1 + (1 - decay) * gW1 * gW1
cache_b2 += decay * cache_b2 + (1 - decay) * gb2 * gb2
cache_b1 += decay * cache_b1 + (1 - decay) * gb1 * gb1
W2 -= lr0 * (gW2 // (cache_W2 + epsilon) + reg * W2)
b2 -= lr0 * (gb2 // (cache_b2 + epsilon) + reg * b2)
W1 -= lr0 * (gW1 // (cache_W1 + epsilon) + reg * W1)
b1 -= lr0 * (gb1 // (cache_b1 + epsilon) + reg * b1)
if j % print_period == 0:
yte_pred, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(yte_pred, Ytest_ind)
losses_test.append(l)
print("test set Cost at iteration epoch=%d, j=%d: %.6f" % (epoch, j, l))
e = error_rate(yte_pred, Ytest)
errors_batch.append(e)
print("Error rate:", e)
ctr = cost(ytr_pred, ytr)
print("traning set cost", ctr)
tr_costs.append(ctr)
pY, _ = forward(Xtest, W1, b1, W2, b2)
#plt.plot(tr_costs, label='tr_costs')
plt.plot(losses_test, label='losses_test RMS')
#plt.plot(errors_batch, label='errors_batch')
# plt.show()
# print("tr_costs", tr_costs)
print("Final error rate:", error_rate(pY, Ytest))
# 2. batch grad with momentum & RMSprop
#
#
# 2.
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
# regular batch gradient descend
tr_costs_momentum = []
errors_batch_momentum = []
losses_test_momentum = []
# momentum coeficient
mu = 0.8
cache_W2 = 1
cache_W1 = 1
cache_b2 = 1
cache_b1 = 1
dW1 = 0
dW2 = 0
db1 = 0
db2 = 0
cW1 = 0
cW2 = 0
cb1 = 0
cb2 = 0
for epoch in range(epochs):
for j in range(number_batches):
xtr = Xtrain[j * batch_size:(j * batch_size + batch_size), :]
ytr = Ytrain_ind[j * batch_size:(j * batch_size + batch_size), :]
ytr_pred, z_tr = forward(xtr, W1, b1, W2, b2)
# gradients
gW2 = derivative_w2(z_tr, ytr, ytr_pred) + reg * W2
gb2 = derivative_b2(ytr, ytr_pred) + reg * b2
gW1 = derivative_w1(xtr, z_tr, ytr, ytr_pred, W2) + reg * W1
gb1 = derivative_b1(z_tr, ytr, ytr_pred, W2) + reg * b1
# potencjalnie pojebalem momentum i velocity
# RMSProp
cache_W2 = decay * cache_W2 + (1 - decay) * gW2 * gW2
cache_W1 = decay * cache_W1 + (1 - decay) * gW1 * gW1
cache_b2 = decay * cache_b2 + (1 - decay) * gb2 * gb2
cache_b1 = decay * cache_b1 + (1 - decay) * gb1 * gb1
cW2 = (gW2 // (cache_W2) + epsilon)
cb2 = (gb2 // (cache_b2) + epsilon)
cW1 = (gW1 // (cache_W1) + epsilon)
cb1 = (gb1 // (cache_b1) + epsilon)
# update velocity
dW2 = mu * dW2 + (1 - mu) * lr0 * cW2
db2 = mu * db2 + (1 - mu) * lr0 * cb2
dW1 = mu * dW1 + (1 - mu) * lr0 * cW1
db1 = mu * db1 + (1 - mu) * lr0 * cb1
# update
W2 -= dW2
W1 -= dW1
b2 -= db2
b1 -= db1
if j % print_period == 0:
yte_pred, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(yte_pred, Ytest_ind)
losses_test_momentum.append(l)
print("test set Cost at iteration epoch=%d, j=%d: %.6f" % (epoch, j, l))
e = error_rate(yte_pred, Ytest)
errors_batch_momentum.append(e)
print("Error rate:", e)
ctr = cost(ytr_pred, ytr)
print("traning set cost", ctr)
tr_costs_momentum.append(ctr)
pY, _ = forward(Xtest, W1, b1, W2, b2)
#plt.plot(tr_costs_momentum, label='tr_costs momentum')
plt.plot(losses_test_momentum, label='losses_test momentum RMS')
#plt.plot(errors_batch, label='errors_batch')
# plt.show()
# print("tr_costs", errors_batch_momentum)
print("Final error rate:", error_rate(pY, Ytest))
plt.legend()
plt.show()
def main():
max_iter = 20 # make it 30 for sigmoid
print_period = 50
Xtrain, Xtest, Ytrain, Ytest = get_normalized_data()
reg = 0.01
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
batch_sz = 500
n_batches = N // batch_sz
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 weights
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
# 1st moment
mW1 = 0
mb1 = 0
mW2 = 0
mb2 = 0
# 2nd moment
vW1 = 0
vb1 = 0
vW2 = 0
vb2 = 0
# hyperparameters
lr0 = 0.001
beta1 = 0.9
beta2 = 0.999
eps = 1e-8
losses_adam = []
errors_adam = []
t = 1
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg * W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg * b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1
# new m
mW1 = beta1 * mW1 + (1 - beta1) * gW1
mb1 = beta1 * mb1 + (1 - beta1) * gb1
mW2 = beta1 * mW2 + (1 - beta1) * gW2
mb2 = beta1 * mb2 + (1 - beta1) * gb2
# new v
vW1 = beta2 * vW1 + (1 - beta2) * gW1 * gW1
vb1 = beta2 * vb1 + (1 - beta2) * gb1 * gb1
vW2 = beta2 * vW2 + (1 - beta2) * gW2 * gW2
vb2 = beta2 * vb2 + (1 - beta2) * gb2 * gb2
# bias correction
correction1 = 1 - beta1**t
hat_mW1 = mW1 / correction1
hat_mb1 = mb1 / correction1
hat_mW2 = mW2 / correction1
hat_mb2 = mb2 / correction1
correction2 = 1 - beta2**t
hat_vW1 = vW1 / correction2
hat_vb1 = vb1 / correction2
hat_vW2 = vW2 / correction2
hat_vb2 = vb2 / correction2
# update t
t += 1
# apply updates to the params
W1 = W1 - lr0 * hat_mW1 / np.sqrt(hat_vW1 + eps)
b1 = b1 - lr0 * hat_mb1 / np.sqrt(hat_vb1 + eps)
W2 = W2 - lr0 * hat_mW2 / np.sqrt(hat_vW2 + eps)
b2 = b2 - lr0 * hat_mb2 / np.sqrt(hat_vb2 + eps)
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_adam.append(l)
print("cost at iter i %d, j %d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_adam.append(e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("final error rate: ", error_rate(pY, Ytest))
print()
plt.plot(losses_adam, label='adam')
pY, _ = forward(Xtest, W1, b1, W2, b2)
plt.legend()
plt.show()
def main():
# compare 3 scenarios:
# 1. batch SGD
# 2. batch SGD with momentum
# 3. batch SGD with Nesterov momentum
max_iter = 20 # make it 30 for sigmoid
print_period = 10
X, Y = get_normalized_data()
lr = 0.00004
reg = 0.01
Xtrain = X[:-1000, ]
Ytrain = Y[:-1000]
Xtest = X[-1000:, ]
Ytest = Y[-1000:]
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
batch_sz = 500
n_batches = N / batch_sz
M = 300
K = 10
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
# # 1. batch
# cost = -16
LL_batch = []
CR_batch = []
for i in xrange(max_iter):
for j in xrange(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# print "first batch cost:", cost(pYbatch, Ybatch)
# updates
W2 -= lr * (derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
b2 -= lr * (derivative_b2(Ybatch, pYbatch) + reg * b2)
W1 -= lr * (derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) +
reg * W1)
b1 -= lr * (derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_batch.append(ll)
print "Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll)
err = error_rate(pY, Ytest)
CR_batch.append(err)
print "Error rate:", err
pY, _ = forward(Xtest, W1, b1, W2, b2)
print "Final error rate:", error_rate(pY, Ytest)
# 2. batch with momentum
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
LL_momentum = []
CR_momentum = []
mu = 0.9
dW2 = 0
db2 = 0
dW1 = 0
db1 = 0
for i in xrange(max_iter):
for j in xrange(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# # updates
dW2 = mu * dW2 - lr * (derivative_w2(Z, Ybatch, pYbatch) +
reg * W2)
W2 += dW2
db2 = mu * db2 - lr * (derivative_b2(Ybatch, pYbatch) + reg * b2)
b2 += db2
dW1 = mu * dW1 - lr * (
derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1)
W1 += dW1
db1 = mu * db1 - lr * (derivative_b1(Z, Ybatch, pYbatch, W2) +
reg * b1)
b1 += db1
if j % print_period == 0:
# # calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_momentum.append(ll)
print "Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll)
err = error_rate(pY, Ytest)
CR_momentum.append(err)
print "Error rate:", err
pY, _ = forward(Xtest, W1, b1, W2, b2)
print "Final error rate:", error_rate(pY, Ytest)
# # 3. batch with Nesterov momentum
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
LL_nest = []
CR_nest = []
mu = 0.9
dW2 = 0
db2 = 0
dW1 = 0
db1 = 0
for i in xrange(max_iter):
for j in xrange(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
dW2 = mu * mu * dW2 - (1 + mu) * lr * (
derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
W2 += dW2
db2 = mu * mu * db2 - (1 + mu) * lr * (
derivative_b2(Ybatch, pYbatch) + reg * b2)
b2 += db2
dW1 = mu * mu * dW1 - (1 + mu) * lr * (
derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1)
W1 += dW1
db1 = mu * mu * db1 - (1 + mu) * lr * (
derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
b1 += db1
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_nest.append(ll)
print "Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll)
err = error_rate(pY, Ytest)
CR_nest.append(err)
print "Error rate:", err
pY, _ = forward(Xtest, W1, b1, W2, b2)
print "Final error rate:", error_rate(pY, Ytest)
plt.plot(LL_batch, label="batch")
plt.plot(LL_momentum, label="momentum")
plt.plot(LL_nest, label="nesterov")
plt.legend()
plt.show()
def main():
# Compare 3 scenarios:
# 1. batch SGD
# 2. batch SGD with momentum
# 3. batch SGD with Nestrov momentum
max_iter = 30
print_period = 10
X_train, X_test, Y_train, Y_test = get_normalized_data()
lr = 0.00004
reg = 0.01
Y_train_ind = y2indicator(Y_train)
Y_test_ind = y2indicator(Y_test)
N, D = X_train.shape
batch_sz = 500
n_batches = N // batch_sz
M = 300
K = 10
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
# save initial weights
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
# 1. batch
# cost = -16
losses_batch = []
errors_batch = []
for i in range(max_iter):
for j in range(n_batches):
Xbatch = X_train[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Y_train_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
W2 -= lr * (derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
b2 -= lr * (derivative_b2(Ybatch, pYbatch) + reg * b2)
W1 -= lr * (derivative_w1(Xbatch, Z,
Ybatch, pYbatch, W2) + reg * W1)
b1 -= lr * (derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
if j % print_period == 0:
pY, _ = forward(X_test, W1, b1, W2, b2)
l = cost(pY, Y_test_ind)
losses_batch.append(l)
print(f'Cost at iteration i={i}, j={j} : {l}')
e = error_rate(pY, Y_test)
errors_batch.append(e)
print("error_rate", e)
pY, _ = forward(X_test, W1, b1, W2, b2)
print(f"Final error rate: {error_rate(pY, Y_test)}")
# 2. batch with momentum
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
losses_momentum = []
errors_momentum = []
mu = 0.9
dW2 = 0
db2 = 0
dW1 = 0
db1 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = X_train[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Y_train_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# gradients
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg * W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg * b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1
# Update velocities
dW2 = mu * dW2 - lr * gW2
db2 = mu * db2 - lr * gb2
dW1 = mu * dW1 - lr * gW1
db1 = mu * db1 - lr * gb1
# updates
W2 += dW2
b2 += db2
W1 += dW1
b1 += db1
if j % print_period == 0:
pY, _ = forward(X_test, W1, b1, W2, b2)
l = cost(pY, Y_test_ind)
losses_momentum.append(l)
print(f'Cost at iteration i={i}, j={j} : {l}')
e = error_rate(pY, Y_test)
errors_momentum.append(e)
print("error_rate", e)
pY, _ = forward(X_test, W1, b1, W2, b2)
print(f"Final error rate: {error_rate(pY, Y_test)}")
# 3. batch with Nesterov momentum
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
losses_nesterov = []
errors_nesterov = []
mu = 0.9
vW2 = 0
vb2 = 0
vW1 = 0
vb1 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = X_train[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Y_train_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# gradients
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg * W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg * b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1
# v update
vW2 = mu * vW2 - lr * gW2
vb2 = mu * vb2 - lr * gb2
vW1 = mu * vW1 - lr * gW1
vb1 = mu * vb1 - lr * gb1
# param update
W2 += mu * vW2 - lr * gW2
b2 += mu * vb2 - lr * gb2
W1 += mu * vW1 - lr * gW1
b1 += mu * vb1 - lr * gb1
if j % print_period == 0:
pY, _ = forward(X_test, W1, b1, W2, b2)
l = cost(pY, Y_test_ind)
losses_nesterov.append(l)
print(f'Cost at iteration i={i}, j={j} : {l}')
e = error_rate(pY, Y_test)
errors_nesterov.append(e)
print("error_rate", e)
pY, _ = forward(X_test, W1, b1, W2, b2)
print(f"Final error rate: {error_rate(pY, Y_test)}")
plt.plot(losses_batch, label='batch')
plt.plot(losses_momentum, label='momentum')
plt.plot(losses_nesterov, label='nesterov')
plt.show()
def main():
max_iter = 20
print_period = 10
Xtrain, Xtest, Ytrain, Ytest = get_normalized_data()
lr = 0.00004
reg = 0.01
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
batch_sz = 500
n_batches = N // batch_sz
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)
#const
LL_batch = []
CR_batch = []
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j*batch_sz: (j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz: (j*batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
#gradient
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg*W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg*b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1
#updates
W2 -= lr*gW2
b2 -= lr*gb2
W1 -= lr*gW1
b1 -= lr*gb1
if j%print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
ll = cost(pY, Ytest_ind)
LL_batch.append(ll)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll))
err = error_rate(pY, Ytest)
CR_batch.append(err)
print("Error rate:", err)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
#RMSprop
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)
#const
LL_rms = []
CR_rms = []
lr0 = 0.001
cache_W2 = 1
cache_b2 = 1
cache_W1 = 1
cache_b1 = 1
decay_rate = 0.999
eps = 1e-10
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j*batch_sz: (j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz: (j*batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
#updates
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg*W2
cache_W2 = decay_rate*cache_W2 + (1 - decay_rate)*gW2*gW2
W2 -= lr0*gW2 / (np.sqrt(cache_W2) + eps)
gb2 = derivative_b2(Ybatch, pYbatch) + reg*b2
cache_b2 = decay_rate*cache_b2 + (1 - decay_rate)*gb2*gb2
b2 -= lr0 * gb2 / (np.sqrt(cache_b2) + eps)
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1
cache_W1 = decay_rate*cache_W1 + (1 - decay_rate)*gW1*gW1
W1 -= lr0 * gW1 / (np.sqrt(cache_W1) + eps)
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1
cache_b1 = decay_rate*cache_b1 + (1 - decay_rate)*gb1*gb1
b1 -= lr0 * gb1 / (np.sqrt(cache_b1) + eps)
if j%print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
ll = cost(pY, Ytest_ind)
LL_rms.append(ll)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll))
err = error_rate(pY, Ytest)
CR_rms.append(err)
print("Error rate:", err)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
plt.plot(LL_batch, label = 'const')
plt.plot(LL_rms, label = 'rms')
plt.legend()
plt.show()
def main():
# 3 scenarios
# 1. batch SGD
# 2. batch SGD with momentum
# 3. batch SGD with Nesterov momentum
max_iter = 15
print_period = 10
Xtrain, Xtest, Ytrain, Ytest = get_normalized_data()
lr = 0.0001
reg = 0.001
# Xtrain = X[:-1000, ]
# Ytrain = Y[:-1000]
# Xtest = X[-1000:, ]
# Ytest = Y[-1000:, ]
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
batch_sz = 500
n_batches = int(N / batch_sz)
M = 300
K = 10
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
# Batch
losses_batch = []
error_batch = []
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
W2 -= lr * (derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
b2 -= lr * (derivative_b2(Ybatch, pYbatch) + reg * b2)
W1 -= lr * (derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) +
reg * W1)
b1 -= lr * (derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
# A = ' '
# A = u"\n| |\n|----------------------| \n(\\__/) || \n(• v •) || \n / D"
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_batch.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
# print(
# u"|----------------------|\n| | \n Costo
# en i=%d, j=%d: \n %.6f" % (i, j, l) + A)
e = error_rate(pY, Ytest)
error_batch.append(e)
print("Ratio de error:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate: ", error_rate(pY, Ytest))
# Momentum
W1 = W1_0.copy()
b1 = b1.copy()
W2 = W2.copy()
b2 = b2.copy()
losses_momentum = []
errors_momentum = []
mu = 0.9
dW2 = 0
db2 = 0
dW1 = 0
db1 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# gradients
gW2 = (derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
gb2 = (derivative_b2(Ybatch, pYbatch) + reg * b2)
gW1 = (derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1)
gb1 = (derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
# update velocities
dW2 = mu * dW2 - lr * gW2
db2 = mu * db2 - lr * gb2
dW1 = mu * dW1 - lr * gW1
db1 = mu * db1 - lr * gb1
W2 += dW2
b2 += db2
W1 += dW1
b1 += db1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_momentum.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_momentum.append(e)
print("Error rate:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate: ", error_rate(pY, Ytest))
# Nesterov momentum
W1 = W1_0.copy()
b1 = b1.copy()
W2 = W2.copy()
b2 = b2.copy()
losses_nesterov = []
errors_nesterov = []
mu = 0.9
vW2 = 0
vb2 = 0
vW1 = 0
vb1 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# gradients
gW2 = (derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
gb2 = (derivative_b2(Ybatch, pYbatch) + reg * b2)
gW1 = (derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1)
gb1 = (derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
# v update
vW2 = mu * vW2 - lr * gW2
vb2 = mu * vb2 - lr * gb2
vW1 = mu * vW1 - lr * gW1
vb1 = mu * vb1 - lr * gb1
# param update
W2 += mu * vW2 - lr * gW2
b2 += mu * vb2 - lr * gb2
W1 += mu * vW1 - lr * gW1
b1 += mu * vb1 - lr * gb1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_nesterov.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_nesterov.append(e)
print("Error rate:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate: ", error_rate(pY, Ytest))
plt.plot(losses_batch, label='batch')
plt.plot(losses_momentum, label='momentum')
plt.plot(losses_nesterov, label='Nesterov')
plt.legend()
plt.show()
def main():
# compare 3 scenarios:
# 1. batch SGD
# 2. batch SGD with momentum
# 3. batch SGD with Nesterov momentum
max_iter = 20 # make it 30 for sigmoid
print_period = 10
X, Y = get_normalized_data()
lr = 0.00004
reg = 0.01
Xtrain = X[:-1000, ]
Ytrain = Y[:-1000]
Xtest = X[-1000:, ]
Ytest = Y[-1000:]
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
batch_sz = 500
n_batches = N // batch_sz
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)
# 1. batch
# cost = -16
LL_batch = []
CR_batch = []
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# print "first batch cost:", cost(pYbatch, Ybatch)
# updates
W2 -= lr * (derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
b2 -= lr * (derivative_b2(Ybatch, pYbatch) + reg * b2)
W1 -= lr * (derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) +
reg * W1)
b1 -= lr * (derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
ll = cost(pY, Ytest_ind)
LL_batch.append(ll)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll))
err = error_rate(pY, Ytest)
CR_batch.append(err)
print("Error rate:", err)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
# 2. batch with momentum
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)
LL_momentum = []
CR_momentum = []
mu = 0.9
dW2 = 0
db2 = 0
dW1 = 0
db1 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
dW2 = mu * dW2 - lr * (derivative_w2(Z, Ybatch, pYbatch) +
reg * W2)
W2 += dW2
db2 = mu * db2 - lr * (derivative_b2(Ybatch, pYbatch) + reg * b2)
b2 += db2
dW1 = mu * dW1 - lr * (
derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1)
W1 += dW1
db1 = mu * db1 - lr * (derivative_b1(Z, Ybatch, pYbatch, W2) +
reg * b1)
b1 += db1
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_momentum.append(ll)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll))
err = error_rate(pY, Ytest)
CR_momentum.append(err)
print("Error rate:", err)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
# 3. batch with Nesterov momentum
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)
LL_nest = []
CR_nest = []
mu = 0.9
# alternate version uses dW
# dW2 = 0
# db2 = 0
# dW1 = 0
# db1 = 0
vW2 = 0
vb2 = 0
vW1 = 0
vb1 = 0
for i in range(max_iter):
for j in range(n_batches):
# because we want g(t) = grad(f(W(t-1) - lr*mu*dW(t-1)))
# dW(t) = mu*dW(t-1) + g(t)
# W(t) = W(t-1) - mu*dW(t)
W1_tmp = W1 - lr * mu * vW1
b1_tmp = b1 - lr * mu * vb1
W2_tmp = W2 - lr * mu * vW2
b2_tmp = b2 - lr * mu * vb2
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
# pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
pYbatch, Z = forward(Xbatch, W1_tmp, b1_tmp, W2_tmp, b2_tmp)
# updates
# dW2 = mu*mu*dW2 - (1 + mu)*lr*(derivative_w2(Z, Ybatch, pYbatch) + reg*W2)
# W2 += dW2
# db2 = mu*mu*db2 - (1 + mu)*lr*(derivative_b2(Ybatch, pYbatch) + reg*b2)
# b2 += db2
# dW1 = mu*mu*dW1 - (1 + mu)*lr*(derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1)
# W1 += dW1
# db1 = mu*mu*db1 - (1 + mu)*lr*(derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1)
# b1 += db1
vW2 = mu * vW2 + derivative_w2(Z, Ybatch, pYbatch) + reg * W2_tmp
W2 -= lr * vW2
vb2 = mu * vb2 + derivative_b2(Ybatch, pYbatch) + reg * b2_tmp
b2 -= lr * vb2
vW1 = mu * vW1 + derivative_w1(Xbatch, Z, Ybatch, pYbatch,
W2_tmp) + reg * W1_tmp
W1 -= lr * vW1
vb1 = mu * vb1 + derivative_b1(Z, Ybatch, pYbatch,
W2_tmp) + reg * b1_tmp
b1 -= lr * vb1
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_nest.append(ll)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll))
err = error_rate(pY, Ytest)
CR_nest.append(err)
print("Error rate:", err)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
plt.plot(LL_batch, label="batch")
plt.plot(LL_momentum, label="momentum")
plt.plot(LL_nest, label="nesterov")
plt.legend()
plt.show()
def main():
max_iter = 10
print_period = 10
X, Y = get_normalized_data()
reg = 0.01
Xtrain = X[:-1000,]
Ytrain = Y[:-1000]
Xtest = X[-1000:,]
Ytest = Y[-1000:]
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
batch_sz = 500
n_batches = N // batch_sz
M = 300
K = 10
W1_0 = np.random.randn(D, M) / np.sqrt(D)
b1_0 = np.zeros(M)
W2_0 = np.random.randn(M, K) / np.sqrt(M)
b2_0 = np.zeros(K)
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
# 1st moment
mW1 = 0
mb1 = 0
mW2 = 0
mb2 = 0
# 2nd moment
vW1 = 0
vb1 = 0
vW2 = 0
vb2 = 0
# hyperparams
lr0 = 0.001
beta1 = 0.9
beta2 = 0.999
eps = 1e-8
# 1. Adam
loss_adam = []
err_adam = []
t = 1
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
# gradients
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg*W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg*b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1
# new m
mW1 = beta1 * mW1 + (1 - beta1) * gW1
mb1 = beta1 * mb1 + (1 - beta1) * gb1
mW2 = beta1 * mW2 + (1 - beta1) * gW2
mb2 = beta1 * mb2 + (1 - beta1) * gb2
# new v
vW1 = beta2 * vW1 + (1 - beta2) * gW1 * gW1
vb1 = beta2 * vb1 + (1 - beta2) * gb1 * gb1
vW2 = beta2 * vW2 + (1 - beta2) * gW2 * gW2
vb2 = beta2 * vb2 + (1 - beta2) * gb2 * gb2
# bias correction
correction1 = 1 - beta1 ** t
hat_mW1 = mW1 / correction1
hat_mb1 = mb1 / correction1
hat_mW2 = mW2 / correction1
hat_mb2 = mb2 / correction1
correction2 = 1 - beta2 ** t
hat_vW1 = vW1 / correction2
hat_vb1 = vb1 / correction2
hat_vW2 = vW2 / correction2
hat_vb2 = vb2 / correction2
# update t
t += 1
# apply updates to the params
W1 = W1 - lr0 * hat_mW1 / np.sqrt(hat_vW1 + eps)
b1 = b1 - lr0 * hat_mb1 / np.sqrt(hat_vb1 + eps)
W2 = W2 - lr0 * hat_mW2 / np.sqrt(hat_vW2 + eps)
b2 = b2 - lr0 * hat_mb2 / np.sqrt(hat_vb2 + eps)
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
loss_adam.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
err = error_rate(pY, Ytest)
err_adam.append(err)
print("Error rate:", err)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
# 2. RMSprop with momentum
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
loss_rms = []
err_rms = []
# comparable hyperparameters for fair comparison
lr0 = 0.001
mu = 0.9
decay_rate = 0.999
eps = 1e-8
# rmsprop cache
cache_W2 = 1
cache_b2 = 1
cache_W1 = 1
cache_b1 = 1
# momentum
dW1 = 0
db1 = 0
dW2 = 0
db2 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg*W2
cache_W2 = decay_rate*cache_W2 + (1 - decay_rate)*gW2*gW2
dW2 = mu * dW2 + (1 - mu) * lr0 * gW2 / (np.sqrt(cache_W2) + eps)
W2 -= dW2
gb2 = derivative_b2(Ybatch, pYbatch) + reg*b2
cache_b2 = decay_rate*cache_b2 + (1 - decay_rate)*gb2*gb2
db2 = mu * db2 + (1 - mu) * lr0 * gb2 / (np.sqrt(cache_b2) + eps)
b2 -= db2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1
cache_W1 = decay_rate*cache_W1 + (1 - decay_rate)*gW1*gW1
dW1 = mu * dW1 + (1 - mu) * lr0 * gW1 / (np.sqrt(cache_W1) + eps)
W1 -= dW1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1
cache_b1 = decay_rate*cache_b1 + (1 - decay_rate)*gb1*gb1
db1 = mu * db1 + (1 - mu) * lr0 * gb1 / (np.sqrt(cache_b1) + eps)
b1 -= db1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
loss_rms.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
err = error_rate(pY, Ytest)
err_rms.append(err)
print("Error rate:", err)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
plt.plot(loss_adam, label='adam')
plt.plot(loss_rms, label='rmsprop')
plt.legend()
plt.show()
CR_batch = []
<<<<<<< HEAD
for i in xrange(max_iter):
for j in xrange(n_batches):
=======
for i in range(max_iter):
for j in range(n_batches):
>>>>>>> upstream/master
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# print "first batch cost:", cost(pYbatch, Ybatch)
# updates
W2 -= lr*(derivative_w2(Z, Ybatch, pYbatch) + reg*W2)
b2 -= lr*(derivative_b2(Ybatch, pYbatch) + reg*b2)
W1 -= lr*(derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1)
b1 -= lr*(derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1)
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_batch.append(ll)
<<<<<<< HEAD
print "Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll)
err = error_rate(pY, Ytest)
CR_batch.append(err)
print "Error rate:", err
def main():
# 3 scenarios
# 1. batch SGD
# 2. batch SGD with momentum
# 3. batch SGD with Nesterov momentum
max_iter = 15
print_period = 10
Xtrain, Xtest, Ytrain, Ytest = get_normalized_data()
lr = 0.0001
reg = 0.001
# Xtrain = X[:-1000, ]
# Ytrain = Y[:-1000]
# Xtest = X[-1000:, ]
# Ytest = Y[-1000:, ]
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
batch_sz = 500
n_batches = int(N / batch_sz)
M = 300
K = 10
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
# Batch
losses_batch = []
error_batch = []
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
W2 -= lr * (derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
b2 -= lr * (derivative_b2(Ybatch, pYbatch) + reg * b2)
W1 -= lr * (derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) +
reg * W1)
b1 -= lr * (derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
# A = ' '
# A = u"\n| |\n|----------------------| \n(\\__/) || \n(• v •) || \n / D"
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_batch.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
# print(
# u"|----------------------|\n| | \n Costo
# en i=%d, j=%d: \n %.6f" % (i, j, l) + A)
e = error_rate(pY, Ytest)
error_batch.append(e)
print("Ratio de error:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate: ", error_rate(pY, Ytest))
# Momentum
W1 = W1_0.copy()
b1 = b1.copy()
W2 = W2.copy()
b2 = b2.copy()
losses_rms = []
errors_rms = []
lr0 = 0.001
cacheW2 = 0
cacheb2 = 0
cacheW1 = 0
cacheb1 = 0
decay_rate = 0.99
eps = 0.000001
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# gradients
gW2 = (derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
gb2 = (derivative_b2(Ybatch, pYbatch) + reg * b2)
gW1 = (derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1)
gb1 = (derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
# caches
cacheW2 = decay_rate * cacheW2 + (1 - decay_rate) * gW2 * gW2
cacheb2 = decay_rate * cacheb2 + (1 - decay_rate) * gb2 * gb2
cacheW1 = decay_rate * cacheW1 + (1 - decay_rate) * gW1 * gW1
cacheb1 = decay_rate * cacheb1 + (1 - decay_rate) * gb1 * gb1
W2 -= lr0 * gW2 / (np.sqrt(cacheW2) + eps)
b2 -= lr0 * gb2 / (np.sqrt(cacheb2) + eps)
W1 -= lr0 * gW1 / (np.sqrt(cacheW1) + eps)
b1 -= lr0 * gb1 / (np.sqrt(cacheb1) + eps)
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_rms.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_rms.append(e)
print("Error rate:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate: ", error_rate(pY, Ytest))
plt.plot(losses_batch, label='batch')
plt.plot(losses_rms, label='rmsprop')
plt.legend()
plt.show()
def main():
max_iter = 20
print_period = 20
Xtrain, Xtest, Ytrain, Ytest = get_normalized_data()
Ytrain_ind = y2indicator(Ytrain) # Target of train data
Ytest_ind = y2indicator(Ytest) # Target of test data
lr = 0.00004
reg = 0.01
N, D = Xtrain.shape
M = 300
K = 10
np.random.seed(123)
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)
batch_sz = 500
n_batches = N // batch_sz # 82
# save initial weights
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
# 1. learning rate = constant
losses_batch = []
errors_batch = []
for i in range(max_iter):
# Xtrain, Ytrain_ind = shuffle(Xtrain, Ytrain_ind)
for j in range(n_batches):
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),] # Target of each batch
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# print "first batch cost:", cost(pYbatch, Ybatch)
# updates
W2 -= lr*(derivative_w2(Z, Ybatch, pYbatch) + reg*W2)
b2 -= lr*(derivative_b2(Ybatch, pYbatch) + reg*b2)
W1 -= lr*(derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1)
b1 -= lr*(derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1)
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_batch.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_batch.append(e)
print("Error rate:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
# 2. RMSprop
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
losses_rms = []
errors_rms = []
'''
in RMSprop you can use a bigger lr,
but if you set this too high you'll get NaN!
if you use the same learning rate within RMSprop and General method, there is only slight difference between them.
'''
lr0 = 0.001
cache_W2 = 1
cache_b2 = 1
cache_W1 = 1
cache_b1 = 1
decay_rate = 0.999
eps = 1e-10
for i in range(max_iter):
# Xtrain, Ytrain_ind = shuffle(Xtrain, Ytrain_ind)
for j in range(n_batches):
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),] # Target of each batch
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# print "first batch cost:", cost(pYbatch, Ybatch)
# # update
# cache_W2 = decay_rate*cache_W2 + (1 - decay_rate)*np.square(derivative_w2(Z, Ybatch, pYbatch) + reg*W2)
# W2 -= lr0 / (np.sqrt(cache_W2) + eps) *(derivative_w2(Z, Ybatch, pYbatch) + reg*W2)
# cache_b2 = decay_rate*cache_b2 + (1 - decay_rate)*np.square(derivative_b2(Ybatch, pYbatch) + reg*b2)
# b2 -= lr0 / (np.sqrt(cache_b2) + eps) *(derivative_b2(Ybatch, pYbatch) + reg*b2)
# cache_W1 = decay_rate*cache_W1 + (1 - decay_rate)*np.square(derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2))
# W1 -= lr0 / (np.sqrt(cache_W1) + eps) *(derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1)
# cache_b1 = decay_rate*cache_b1 + (1 - decay_rate)*np.square(derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1)
# b1 -= lr0 / (np.sqrt(cache_b1) + eps) *(derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1)
# updates
# 更聰明的寫法，是把上面式子中，會重複計算到的部分提出來計算並指派給變數，讓它只計算一次，這樣會加速
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg*W2
cache_W2 = decay_rate*cache_W2 + (1 - decay_rate)*gW2*gW2
W2 -= lr0 * gW2 / (np.sqrt(cache_W2) + eps)
gb2 = derivative_b2(Ybatch, pYbatch) + reg*b2
cache_b2 = decay_rate*cache_b2 + (1 - decay_rate)*gb2*gb2
b2 -= lr0 * gb2 / (np.sqrt(cache_b2) + eps)
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1
cache_W1 = decay_rate*cache_W1 + (1 - decay_rate)*gW1*gW1
W1 -= lr0 * gW1 / (np.sqrt(cache_W1) + eps)
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1
cache_b1 = decay_rate*cache_b1 + (1 - decay_rate)*gb1*gb1
b1 -= lr0 * gb1 / (np.sqrt(cache_b1) + eps)
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_rms.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_rms.append(e)
print("Error rate:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
plt.plot(losses_batch, label='contant')
plt.plot(losses_rms, label='RMSprop')
plt.legend()
plt.show()
b2_0 = b2.copy()
# 1. batch
losses_batch = []
errors_batch = []
for i in range(max_iter):
for j in range(n_batches):
>>>>>>> upstream/master
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# print "first batch cost:", cost(pYbatch, Ybatch)
# updates
W2 -= lr*(derivative_w2(Z, Ybatch, pYbatch) + reg*W2)
b2 -= lr*(derivative_b2(Ybatch, pYbatch) + reg*b2)
W1 -= lr*(derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1)
b1 -= lr*(derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1)
if j % print_period == 0:
<<<<<<< HEAD
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_batch.append(ll)
print "Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll)
err = error_rate(pY, Ytest)
CR_batch.append(err)
print "Error rate:", err
def main():
max_iter = 20
print_period = 10
X_train, X_test, Y_train, Y_test = get_normalized_data()
lr = 0.00004
reg = 0.01
Y_train_ind = y2indicator(Y_train)
Y_test_ind = y2indicator(Y_test)
N, D = X_train.shape
batch_sz = 500
n_batches = N // batch_sz
M = 300
K = 10
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(K)
b2 = np.zeros(K)
# copy weights
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
# 1. Constant Learning rate
losses_batch = []
errors_batch = []
for i in range(max_iter):
for j in range(n_batches):
Xbatch = X_train[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Y_train_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
W2 -= lr * (derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
b2 -= lr * (derivative_b2(Ybatch, pYbatch) + reg * b2)
W1 -= lr * (derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) +
reg * W1)
b1 -= lr * (derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
if j % print_period == 0:
pY, _ = forward(X_test, W1, b1, W2, b2)
l = cost(pY, Y_test_ind)
losses_batch.append(l)
print(f'Cost at iteration i={i}, j={j} : {l}')
e = error_rate(pY, Y_test)
errors_batch.append(e)
print("error_rate", e)
pY, _ = forward(X_test, W1, b1, W2, b2)
batch_error = error_rate(pY, Y_test)
print(f"Final batch error rate: {batch_error}")
# 2. RMSProp
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
losses_RMSP = []
errors_RMSP = []
lr0 = 0.001
cache_W1 = 1
cache_b1 = 1
cache_W2 = 1
cache_b2 = 1
decay = 0.999
epsilon = 1e-10
for i in range(max_iter):
for j in range(n_batches):
Xbatch = X_train[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Y_train_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg * W2
cache_W2 = decay * cache_W2 + (1 - decay) * gW2 * gW2
W2 -= lr0 * gW2 / (np.sqrt(cache_W2) + epsilon)
gb2 = derivative_b2(Ybatch, pYbatch) + reg * b2
cache_b2 = decay * cache_b2 + (1 - decay) * gb2 * gb2
b2 -= lr0 * gb2 / (np.sqrt(cache_b2) + epsilon)
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1
cache_W1 = decay * cache_W1 + (1 - decay) * gW1 * gW1
W1 -= lr0 * gW1 / (np.sqrt(cache_W1) + epsilon)
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1
cache_b1 = decay * cache_b1 + (1 - decay) * gb1 * gb1
b1 -= lr0 * gb1 / (np.sqrt(cache_b1) + epsilon)
if j % print_period == 0:
pY, _ = forward(X_test, W1, b1, W2, b2)
l = cost(pY, Y_test_ind)
losses_RMSP.append(l)
print(f'Cost at iteration i={i}, j={j} : {l}')
e = error_rate(pY, Y_test)
errors_RMSP.append(e)
print("error_rate", e)
pY, _ = forward(X_test, W1, b1, W2, b2)
print(f"Final RMSProp error rate: {error_rate(pY, Y_test)}")
print(f"Final batch error rate: {batch_error}")
plt.plot(losses_batch, label='batch cost')
plt.plot(losses_RMSP, label='RMSProp cost')
plt.legend()
plt.show()
def main():
# compare 2 scenarios:
# 1. batch GD with RMSProp and momentum
# 2. Adam GD
max_iter = 20
print_period = 10
X, Y = get_normalized_data()
reg = 0.01
Xtrain, Ytrain = X[:-1000, :], Y[:-1000]
Xtest, Ytest = X[-1000:, :], Y[-1000:]
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
M = 300 # number of hidden layer units
K = len(set(Ytrain))
batch_size = 500
n_batches = N // batch_size
# randomly initialize weights:
W1_0 = np.random.randn(D, M) / np.sqrt(D)
b1_0 = np.zeros(M)
W2_0 = np.random.randn(M, K) / np.sqrt(M)
b2_0 = np.zeros(K)
# 1. batch GD with RMSProp and momentum:
print('\nperforming batch GD with RMSProp and momentum...')
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
LL_rm = []
CR_rm = []
# hyperparams:
lr0 = 0.001
#lr0 = 0.0001
mu = 0.9
decay = 0.999
eps = 10e-9
# momentum (velocity terms):
dW1 = 0
db1 = 0
dW2 = 0
db2 = 0
# rms-prop cache (with no bias correction):
cache_W2 = 1
cache_b2 = 1
cache_W1 = 1
cache_b1 = 1
t0 = datetime.now()
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_size:(j + 1) * batch_size, :]
Ybatch = Ytrain_ind[j * batch_size:(j + 1) * batch_size, :]
p_Ybatch, Z = forward(Xbatch, W1, b1, W2, b2)
#print(Z.shape, p_Ybatch.shape, Ybatch.shape)
#print('First batch cost:', cost(p_Ybatch, Ybatch))
# updates:
# (note: we utilize a bit different version of momentum)
gW2 = (derivative_W2(Z, Ybatch, p_Ybatch) + reg * W2)
cache_W2 = decay * cache_W2 + (1 - decay) * gW2 * gW2
dW2 = mu * dW2 + (1 - mu) * lr0 * gW2 / (np.sqrt(cache_W2 + eps))
W2 -= dW2
#dW2 = mu*dW2 - lr0*gW2 / (np.sqrt(cache_W2) + eps)
#W2 += dW2
gb2 = (derivative_b2(Ybatch, p_Ybatch) + reg * b2)
cache_b2 = decay * cache_b2 + (1 - decay) * gb2 * gb2
db2 = mu * db2 + (1 - mu) * lr0 * gb2 / (np.sqrt(cache_b2 + eps))
b2 -= db2
#db2 = mu*db2 - lr0*gb2 / (np.sqrt(cache_b2) + eps)
#b2 += db2
gW1 = (derivative_W1(Xbatch, Z, Ybatch, p_Ybatch, W2) + reg * W1)
cache_W1 = decay * cache_W1 + (1 - decay) * gW1 * gW1
dW1 = mu * dW1 + (1 - mu) * lr0 * gW1 / (np.sqrt(cache_W1 + eps))
W1 -= dW1
#dW1 = mu*dW1 - lr0*gW1 / (np.sqrt(cache_W1) + eps)
#W1 += dW1
gb1 = (derivative_b1(Z, Ybatch, p_Ybatch, W2) + reg * b1)
cache_b1 = decay * cache_b1 + (1 - decay) * gb1 * gb1
db1 = mu * db1 + (1 - mu) * lr0 * gb1 / (np.sqrt(cache_b1 + eps))
b1 -= db1
#db1 = mu*db1 - lr0*gb1 / (np.sqrt(cache_b1) + eps)
#b1 += db1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
#print('pY:', pY)
ll = cost(pY, Ytest_ind)
LL_rm.append(ll)
print('\ni: %d, j: %d, cost: %.6f' % (i, j, ll))
error = error_rate(pY, Ytest)
CR_rm.append(error)
print('error rate:', error)
dt1 = datetime.now() - t0
pY, _ = forward(Xtest, W1, b1, W2, b2)
print('\nFinal error rate:', error_rate(pY, Ytest))
print('Elapsed time for batch GD with RMSProp and momentum:', dt1)
# plot the cost
plt.plot(LL_rm)
plt.title('Cost for batch GD with RMSProp and momentum')
plt.show()
# 2. Adam optimizer
print('\nperforming Adam optimizer...')
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
# hyperparams:
lr = 0.001
beta1 = 0.9
beta2 = 0.999
eps = 10e-9
# 1st moment:
mW1 = 0
mb1 = 0
mW2 = 0
mb2 = 0
# 2nd moment:
vW1 = 0
vb1 = 0
vW2 = 0
vb2 = 0
LL_adam = []
CR_adam = []
t0 = datetime.now()
t = 1 # index; used instead of j, because j starts with 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_size:(j + 1) * batch_size, :]
Ybatch = Ytrain_ind[j * batch_size:(j + 1) * batch_size, :]
p_Ybatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates:
# gradients:
gW2 = derivative_W2(Z, Ybatch, p_Ybatch) + reg * W2
gb2 = derivative_b2(Ybatch, p_Ybatch) + reg * b2
gW1 = derivative_W1(Xbatch, Z, Ybatch, p_Ybatch, W2) + reg * W1
gb1 = derivative_b1(Z, Ybatch, p_Ybatch, W2) + reg * b1
# 1st moment:
mW2 = beta1 * mW2 + (1 - beta1) * gW2
mb2 = beta1 * mb2 + (1 - beta1) * gb2
mW1 = beta1 * mW1 + (1 - beta1) * gW1
mb1 = beta1 * mb1 + (1 - beta1) * gb1
# 2nd moment:
vW2 = beta2 * vW2 + (1 - beta2) * gW2 * gW2
vb2 = beta2 * vb2 + (1 - beta2) * gb2 * gb2
vW1 = beta2 * vW1 + (1 - beta2) * gW1 * gW1
vb1 = beta2 * vb1 + (1 - beta2) * gb1 * gb1
# bias correction:
mW2_bc = mW2 / (1 - beta1**t)
mb2_bc = mb2 / (1 - beta1**t)
mW1_bc = mW1 / (1 - beta1**t)
mb1_bc = mb1 / (1 - beta1**t)
vW2_bc = vW2 / (1 - beta2**t)
vb2_bc = vb2 / (1 - beta2**t)
vW1_bc = vW1 / (1 - beta2**t)
vb1_bc = vb1 / (1 - beta2**t)
# weights and biases (parameters):
W2 = W2 - lr * mW2_bc / np.sqrt(vW2_bc + eps)
b2 = b2 - lr * mb2_bc / np.sqrt(vb2_bc + eps)
W1 = W1 - lr * mW1_bc / np.sqrt(vW1_bc + eps)
b1 = b1 - lr * mb1_bc / np.sqrt(vb1_bc + eps)
t += 1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
ll = cost(pY, Ytest_ind)
LL_adam.append(ll)
print('\ni: %d, j: %d, cost: %.6f' % (i, j, ll))
error = error_rate(pY, Ytest)
CR_adam.append(error)
print('error rate:', error)
dt2 = datetime.now() - t0
pY, _ = forward(Xtest, W1, b1, W2, b2)
print('\nFinal error rate:', error_rate(pY, Ytest))
print('Elapsed time for Adam optimizer:', dt2)
# plot the cost
plt.plot(LL_adam)
plt.title('Cost for Adam optimizer')
plt.show()
# plot costs from the two experiments together:
plt.plot(LL_rm, label='RMSProp with momentum')
plt.plot(LL_adam, label='Adam optimizer')
plt.title('Cost')
plt.legend()
plt.show()
def main():
# compare 3:
# 1. batch SGD
# 2. batch SGD with momentum
# 3. batch SGD with Nesterov momentum
# all with L2 regularization
print_period = 10
X, Y = get_normalized_data()
lr = 0.00004
reg = 0.01
Xtrain = X[:-1000, ]
Ytrain = Y[:-1000]
Xtest = X[-1000:, ]
Ytest = Y[-1000:]
N, D = Xtrain.shape
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
M = 300
K = 10
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
# regular batch gradient descend
epochs = 30
tr_costs = []
errors_batch = []
losses_test = []
batch_size = 500
number_batches = int(N // batch_size)
#max_iter = 30
# 1.
for epoch in range(epochs):
for j in range(number_batches):
xtr = Xtrain[j * batch_size:(j * batch_size + batch_size), :]
ytr = Ytrain_ind[j * batch_size:(j * batch_size + batch_size), :]
ytr_pred, z_tr = forward(xtr, W1, b1, W2, b2)
W2 -= lr * (derivative_w2(z_tr, ytr, ytr_pred) + reg * W2)
b2 -= lr * (derivative_b2(ytr, ytr_pred) + reg * b2)
W1 -= lr * (derivative_w1(xtr, z_tr, ytr, ytr_pred, W2) + reg * W1)
b1 -= lr * (derivative_b1(z_tr, ytr, ytr_pred, W2) + reg * b1)
if j % print_period == 0:
yte_pred, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(yte_pred, Ytest_ind)
losses_test.append(l)
print("test set Cost at iteration epoch=%d, j=%d: %.6f" % (epoch, j, l))
e = error_rate(yte_pred, Ytest)
errors_batch.append(e)
print("Error rate:", e)
ctr = cost(ytr_pred, ytr)
print("traning set cost", ctr)
tr_costs.append(ctr)
pY, _ = forward(Xtest, W1, b1, W2, b2)
#plt.plot(tr_costs, label='tr_costs')
plt.plot(losses_test, label='losses_test')
#plt.plot(errors_batch, label='errors_batch')
# plt.show()
# print("tr_costs", tr_costs)
print("Final error rate:", error_rate(pY, Ytest))
# 2.
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
# regular batch gradient descend
tr_costs_momentum = []
errors_batch_momentum = []
losses_test_momentum = []
# momentum coeficient
mu = 0.9
dW1 = 0
dW2 = 0
db1 = 0
db2 = 0
for epoch in range(epochs):
for j in range(number_batches):
xtr = Xtrain[j * batch_size:(j * batch_size + batch_size), :]
ytr = Ytrain_ind[j * batch_size:(j * batch_size + batch_size), :]
ytr_pred, z_tr = forward(xtr, W1, b1, W2, b2)
# gradients
gW2 = derivative_w2(z_tr, ytr, ytr_pred) + reg * W2
gb2 = derivative_b2(ytr, ytr_pred) + reg * b2
gW1 = derivative_w1(xtr, z_tr, ytr, ytr_pred, W2) + reg * W1
gb1 = derivative_b1(z_tr, ytr, ytr_pred, W2) + reg * b1
# update velocity
dW2 = mu * dW2 - lr * gW2
db2 = mu * db2 - lr * gb2
dW1 = mu * dW1 - lr * gW1
db1 = mu * db1 - lr * gb1
# update
W2 += dW2
W1 += dW1
b2 += db2
b1 += db1
if j % print_period == 0:
yte_pred, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(yte_pred, Ytest_ind)
losses_test_momentum.append(l)
print("test set Cost at iteration epoch=%d, j=%d: %.6f" % (epoch, j, l))
e = error_rate(yte_pred, Ytest)
errors_batch_momentum.append(e)
print("Error rate:", e)
ctr = cost(ytr_pred, ytr)
print("traning set cost", ctr)
tr_costs_momentum.append(ctr)
pY, _ = forward(Xtest, W1, b1, W2, b2)
#plt.plot(tr_costs_momentum, label='tr_costs momentum')
plt.plot(losses_test_momentum, label='losses_test momentum')
#plt.plot(errors_batch, label='errors_batch')
# plt.show()
# print("tr_costs", errors_batch_momentum)
print("Final error rate:", error_rate(pY, Ytest))
# 3.
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
# regular batch gradient descend
tr_costs_nesterov = []
errors_batch_nesterov = []
losses_test_nesterov = []
# momentum coeficient
mu = 0.9
vW1 = 0
vW2 = 0
vb1 = 0
vb2 = 0
for epoch in range(epochs):
for j in range(number_batches):
xtr = Xtrain[j * batch_size:(j * batch_size + batch_size), :]
ytr = Ytrain_ind[j * batch_size:(j * batch_size + batch_size), :]
ytr_pred, z_tr = forward(xtr, W1, b1, W2, b2)
# gradients
gW2 = derivative_w2(z_tr, ytr, ytr_pred) + reg * W2
gb2 = derivative_b2(ytr, ytr_pred) + reg * b2
gW1 = derivative_w1(xtr, z_tr, ytr, ytr_pred, W2) + reg * W1
gb1 = derivative_b1(z_tr, ytr, ytr_pred, W2) + reg * b1
# update velocity
vW2 = mu * vW2 - lr * gW2
vb2 = mu * vb2 - lr * gb2
vW1 = mu * vW1 - lr * gW1
vb1 = mu * vb1 - lr * gb1
# update
W2 += mu * vW2 - lr * gW2
W1 += mu * vW1 - lr * gW1
b2 += mu * vb2 - lr * gb2
b1 += mu * vb1 - lr * gb1
if j % print_period == 0:
yte_pred, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(yte_pred, Ytest_ind)
losses_test_nesterov.append(l)
print("test set Cost at iteration epoch=%d, j=%d: %.6f" % (epoch, j, l))
e = error_rate(yte_pred, Ytest)
errors_batch_nesterov.append(e)
print("Error rate:", e)
ctr = cost(ytr_pred, ytr)
print("traning set cost", ctr)
tr_costs_nesterov.append(ctr)
pY, _ = forward(Xtest, W1, b1, W2, b2)
#plt.plot(tr_costs_nesterov, label='tr_costs_nesterov')
plt.plot(losses_test_nesterov, label='losses_test_nesterov')
#plt.plot(errors_batch_nesterov, label='errors_batch')
plt.legend()
plt.show()
# print("tr_costs_nesterov", errors_batch_momentum)
print("Final error rate nesterov:", error_rate(pY, Ytest))
def main(): ''' RMSprop is a form adaptative learning rate which decreases over time ''' max_iter = 20 #for RelU #max_iter = 30 #for sigmoid print_period = 10 X, Y = get_normalized_data() lr = 0.0004 reg = 0.01 Xtrain = X[:-1000,] Ytrain = Y[:-1000] Xtest = X[-1000:,] Ytest = Y[-1000:] Ytrain_ind = y2indicator(Ytrain) Ytest_ind = y2indicator(Ytest) N, D = Xtrain.shape batch_sz = 500 n_batches = N / batch_sz M =300 K=10 #1. batch SGD W1 = np.random.randn(D, M) / 28 b1 = np.zeros(M) W2 = np.random.randn(M, K) / np.sqrt(M) b2 = np.zeros(K) LL_batch = [] CR_batch = [] for i in xrange(max_iter): for j in xrange(n_batches): Xbatch = Xtrain[j*batch_sz:((j+1)*batch_sz), :] Ybatch = Ytrain_ind[j*batch_sz:((j+1)*batch_sz), :] pYbatch, Z = forward(Xbatch, W1, b1, W2, b2) W2 -= lr*(derivative_w2(Z, Ybatch, pYbatch) + reg*W2) b2 -= lr*(derivative_b2(Ybatch,pYbatch) + reg*b2) W1 -= lr*(derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1) b1 -= lr*(derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1) if j % print_period ==0: pY, _ = forward(Xtest, W1, b1, W2, b2) ll = cost(pY, Ytest_ind) LL_batch.append(ll) print "Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll) err = error_rate(pY, Ytest) CR_batch.append(err) print "Error rate:", err pY, _ = forward(Xtest, W1, b1, W2, b2) print "Final error rate:", error_rate(pY, Ytest) #2. RMSProp W1 = np.random.randn(D, M) / 28 b1 = np.zeros(M) W2 = np.random.randn(M, K) / np.sqrt(M) b2 = np.zeros(K) LL_rms = [] CR_rms = [] lr0 = 0.001 cache_W2 = 0 cache_b2 = 0 cache_W1 = 0 cache_b1 = 0 decay_rate = 1 - 1e-5 eps = 1e-10 for i in xrange(max_iter): for j in xrange(n_batches): Xbatch = Xtrain[j*batch_sz:((j+1)*batch_sz), :] Ybatch = Ytrain_ind[j*batch_sz:((j+1)*batch_sz), :] pYbatch, Z = forward(Xbatch, W1, b1, W2, b2) #updates gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg*W2 cache_W2 = decay_rate*cache_W2 + (1-decay_rate)*gW2*gW2 W2 -= lr0*gW2 /(np.sqrt(cache_W2) + eps) gb2 = derivative_b2(Ybatch,pYbatch) + reg*b2 cache_b2 = decay_rate*cache_b2 + (1-decay_rate)*gb2*gb2 b2 -= lr0*gb2 /(np.sqrt(cache_b2) + eps) gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1 cache_W1 = decay_rate*cache_W1 + (1-decay_rate)*gW1*gW1 W1 -= lr0*gW1 /(np.sqrt(cache_W1) + eps) gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1 cache_b1 = decay_rate*cache_b1 + (1-decay_rate)*gb1*gb1 b1 -= lr0*gb1 /(np.sqrt(cache_b1) + eps) if j % print_period ==0: pY, _ = forward(Xtest, W1, b1, W2, b2) ll = cost(pY, Ytest_ind) LL_rms.append(ll) print "RMS Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll) err = error_rate(pY, Ytest) CR_rms.append(err) print "RMS Error rate:", err pY, _ = forward(Xtest, W1, b1, W2, b2) print "RMS Final error rate:", error_rate(pY, Ytest) plt.plot(LL_batch, label='batch') plt.plot(LL_rms, label='rms') plt.legend() plt.show()
def main():
# compare 3 scenarios:
# 1. batch SGD
# 2. batch SGD with momentum
# 3. batch SGD with Nesterov momentum
max_iter = 20 # make it 30 for sigmoid
print_period = 50
Xtrain, Xtest, Ytrain, Ytest = get_normalized_data()
lr = 0.00004
reg = 0.01
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
batch_sz = 500
n_batches = N // batch_sz
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 weights
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
# 1. batch
losses_batch = []
errors_batch = []
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# print "first batch cost:", cost(pYbatch, Ybatch)
# updates
W2 -= lr*(derivative_w2(Z, Ybatch, pYbatch) + reg*W2)
b2 -= lr*(derivative_b2(Ybatch, pYbatch) + reg*b2)
W1 -= lr*(derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1)
b1 -= lr*(derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1)
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_batch.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_batch.append(e)
print("Error rate:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
# 2. batch with momentum
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
losses_momentum = []
errors_momentum = []
mu = 0.9
dW2 = 0
db2 = 0
dW1 = 0
db1 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# gradients
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg*W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg*b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1
# update velocities
dW2 = mu*dW2 - lr*gW2
db2 = mu*db2 - lr*gb2
dW1 = mu*dW1 - lr*gW1
db1 = mu*db1 - lr*gb1
# updates
W2 += dW2
b2 += db2
W1 += dW1
b1 += db1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_momentum.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_momentum.append(e)
print("Error rate:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
# 3. batch with Nesterov momentum
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
losses_nesterov = []
errors_nesterov = []
mu = 0.9
vW2 = 0
vb2 = 0
vW1 = 0
vb1 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg*W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg*b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1
# v update
vW2 = mu*vW2 - lr*gW2
vb2 = mu*vb2 - lr*gb2
vW1 = mu*vW1 - lr*gW1
vb1 = mu*vb1 - lr*gb1
# param update
W2 += mu*vW2 - lr*gW2
b2 += mu*vb2 - lr*gb2
W1 += mu*vW1 - lr*gW1
b1 += mu*vb1 - lr*gb1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
losses_nesterov.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
e = error_rate(pY, Ytest)
errors_nesterov.append(e)
print("Error rate:", e)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
plt.plot(losses_batch, label="batch")
plt.plot(losses_momentum, label="momentum")
plt.plot(losses_nesterov, label="nesterov")
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 = 10
print_period = 10
X, Y = get_normalized_data()
reg = 0.01
Xtrain = X[:-1000, ]
Ytrain = Y[:-1000]
Xtest = X[-1000:, ]
Ytest = Y[-1000:]
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
batch_sz = 500
n_batches = N // batch_sz
M = 300
K = 10
W1_0 = np.random.randn(D, M) / np.sqrt(D)
b1_0 = np.zeros(M)
W2_0 = np.random.randn(M, K) / np.sqrt(M)
b2_0 = np.zeros(K)
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
# 1st moment
mW1 = 0
mb1 = 0
mW2 = 0
mb2 = 0
# 2nd moment
vW1 = 0
vb1 = 0
vW2 = 0
vb2 = 0
# hyperparams
lr0 = 0.001
beta1 = 0.9
beta2 = 0.999
eps = 1e-8
# 1. Adam
loss_adam = []
err_adam = []
t = 1
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
# gradients
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg * W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg * b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1
# new m
mW1 = beta1 * mW1 + (1 - beta1) * gW1
mb1 = beta1 * mb1 + (1 - beta1) * gb1
mW2 = beta1 * mW2 + (1 - beta1) * gW2
mb2 = beta1 * mb2 + (1 - beta1) * gb2
# new v
vW1 = beta2 * vW1 + (1 - beta2) * gW1 * gW1
vb1 = beta2 * vb1 + (1 - beta2) * gb1 * gb1
vW2 = beta2 * vW2 + (1 - beta2) * gW2 * gW2
vb2 = beta2 * vb2 + (1 - beta2) * gb2 * gb2
# bias correction
correction1 = 1 - beta1**t
hat_mW1 = mW1 / correction1
hat_mb1 = mb1 / correction1
hat_mW2 = mW2 / correction1
hat_mb2 = mb2 / correction1
correction2 = 1 - beta2**t
hat_vW1 = vW1 / correction2
hat_vb1 = vb1 / correction2
hat_vW2 = vW2 / correction2
hat_vb2 = vb2 / correction2
# update t
t += 1
# apply updates to the params
W1 = W1 - lr0 * hat_mW1 / np.sqrt(hat_vW1 + eps)
b1 = b1 - lr0 * hat_mb1 / np.sqrt(hat_vb1 + eps)
W2 = W2 - lr0 * hat_mW2 / np.sqrt(hat_vW2 + eps)
b2 = b2 - lr0 * hat_mb2 / np.sqrt(hat_vb2 + eps)
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
loss_adam.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
err = error_rate(pY, Ytest)
err_adam.append(err)
print("Error rate:", err)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
# 2. RMSprop with momentum
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
loss_rms = []
err_rms = []
# comparable hyperparameters for fair comparison
lr0 = 0.001
mu = 0.9
decay_rate = 0.999
eps = 1e-8
# rmsprop cache
cache_W2 = 1
cache_b2 = 1
cache_W1 = 1
cache_b1 = 1
# momentum
dW1 = 0
db1 = 0
dW2 = 0
db2 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = Xtrain[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Ytrain_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg * W2
cache_W2 = decay_rate * cache_W2 + (1 - decay_rate) * gW2 * gW2
dW2 = mu * dW2 + (1 - mu) * lr0 * gW2 / (np.sqrt(cache_W2) + eps)
W2 -= dW2
gb2 = derivative_b2(Ybatch, pYbatch) + reg * b2
cache_b2 = decay_rate * cache_b2 + (1 - decay_rate) * gb2 * gb2
db2 = mu * db2 + (1 - mu) * lr0 * gb2 / (np.sqrt(cache_b2) + eps)
b2 -= db2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1
cache_W1 = decay_rate * cache_W1 + (1 - decay_rate) * gW1 * gW1
dW1 = mu * dW1 + (1 - mu) * lr0 * gW1 / (np.sqrt(cache_W1) + eps)
W1 -= dW1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1
cache_b1 = decay_rate * cache_b1 + (1 - decay_rate) * gb1 * gb1
db1 = mu * db1 + (1 - mu) * lr0 * gb1 / (np.sqrt(cache_b1) + eps)
b1 -= db1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
l = cost(pY, Ytest_ind)
loss_rms.append(l)
print("Cost at iteration i=%d, j=%d: %.6f" % (i, j, l))
err = error_rate(pY, Ytest)
err_rms.append(err)
print("Error rate:", err)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print("Final error rate:", error_rate(pY, Ytest))
plt.plot(loss_adam, label='adam')
plt.plot(loss_rms, label='rmsprop')
plt.legend()
plt.show()
def main():
max_iter = 10
print_period = 10
X_train, X_test, Y_train, Y_test = get_normalized_data()
reg = 0.01
Y_train_ind = y2indicator(Y_train)
Y_test_ind = y2indicator(Y_test)
N, D = X_train.shape
batch_sz = 500
n_batches = N // batch_sz
M = 300
K = 10
W1_0 = np.random.randn(D, M) / np.sqrt(D)
b1_0 = np.zeros(M)
W2_0 = np.random.randn(M, K) / np.sqrt(K)
b2_0 = np.zeros(K)
# .1 Adam
W1 = W1_0.copy()
W2 = W2_0.copy()
b1 = b1_0.copy()
b2 = b2_0.copy()
losses_adam = []
errors_adam = []
# 1st moment
mW1 = 0
mW2 = 0
mb1 = 0
mb2 = 0
# 2nd moment
vW1 = 0
vW2 = 0
vb1 = 0
vb2 = 0
# Hyperparams
eps = 1e-8
lr = 0.001
beta1 = 0.9
beta2 = 0.999
t = 1
for i in range(max_iter):
for j in range(n_batches):
Xbatch = X_train[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Y_train_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
# gradients
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg * W2
gb2 = derivative_b2(Ybatch, pYbatch) + reg * b2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1
# new m
mW1 = beta1 * mW1 + (1 - beta1) * gW1
mb1 = beta1 * mb1 + (1 - beta1) * gb1
mW2 = beta1 * mW2 + (1 - beta1) * gW2
mb2 = beta1 * mb2 + (1 - beta1) * gb2
# new v
vW2 = beta2 * vW2 + (1 - beta2) * gW2 * gW2
vb2 = beta2 * vb2 + (1 - beta2) * gb2 * gb2
vW1 = beta2 * vW1 + (1 - beta2) * gW1 * gW1
vb1 = beta2 * vb1 + (1 - beta2) * gb1 * gb1
# bias correction
correction1 = 1 - beta1 ** t
mW1_hat = mW1 / correction1
mb1_hat = mb1 / correction1
mW2_hat = mW2 / correction1
mb2_hat = mb2 / correction1
#
correction2 = 1 - beta2 ** t
vb2_hat = vb2 / correction2
vb1_hat = vb1 / correction2
vW2_hat = vW2 / correction2
vW1_hat = vW1 / correction2
t += 1
# weights
W1 = W1 - lr * mW1_hat / np.sqrt(vW1_hat + eps)
b1 = b1 - lr * mb1_hat / np.sqrt(vb1_hat + eps)
W2 = W2 - lr * mW2_hat / np.sqrt(vW2_hat + eps)
b2 = b2 - lr * mb2_hat / np.sqrt(vb2_hat + eps)
if j % print_period == 0:
pY, _ = forward(X_test, W1, b1, W2, b2)
l = cost(pY, Y_test_ind)
losses_adam.append(l)
print(f'Adam Cost at iteration i={i}, j={j} : {l}')
e = error_rate(pY, Y_test)
errors_adam.append(e)
print("error_rate", e)
pY, _ = forward(X_test, W1, b1, W2, b2)
adam_error = error_rate(pY, Y_test)
# 3. RMSProp with momentum
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
losses_rms = []
errors_rms = []
# comparable hyper parameters for fair
lr0 = 0.001
mu = 0.9
decay_rate = 0.999
eps = 1e-8
# rmsprop cache
cache_W2 = 1
cache_b2 = 1
cache_W1 = 1
cache_b1 = 1
# momentum
dW1 = 0
db1 = 0
dW2 = 0
db2 = 0
for i in range(max_iter):
for j in range(n_batches):
Xbatch = X_train[j * batch_sz:(j * batch_sz + batch_sz), ]
Ybatch = Y_train_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# updates
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg * W2
cache_W2 = decay_rate * cache_W2 + (1 - decay_rate) * gW2 * gW2
dW2 = mu * dW2 + (1 - mu) * lr0 * gW2 / (np.sqrt(cache_W2) + eps)
W2 -= dW2
gb2 = derivative_b2(Ybatch, pYbatch) + reg * b2
cache_b2 = decay_rate * cache_b2 + (1 - decay_rate) * gb2 * gb2
db2 = mu * db2 + (1 - mu) * lr0 * gb2 / (np.sqrt(cache_b2) + eps)
b2 -= db2
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1
cache_W1 = decay_rate * cache_W1 + (1 - decay_rate) * gW1 * gW1
dW1 = mu * dW1 + (1 - mu) * lr0 * gW1 / (np.sqrt(cache_W1) + eps)
W1 -= dW1
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1
cache_b1 = decay_rate * cache_b1 + (1 - decay_rate) * gb1 * gb1
db1 = mu * db1 + (1 - mu) * lr0 * gb1 / (np.sqrt(cache_b1) + eps)
b1 -= db1
if j % print_period == 0:
pY, _ = forward(X_test, W1, b1, W2, b2)
l = cost(pY, Y_test_ind)
losses_rms.append(l)
print(f'Cost at iteration i={i}, j={j} : {l}')
err = error_rate(pY, Y_test)
errors_rms.append(err)
print("Error rate:", err)
pY, _ = forward(X_test, W1, b1, W2, b2)
rms_error = error_rate(pY, Y_test)
print(f"Final RMSProp error rate: {rms_error}")
print(f"Final Adam error rate: {adam_error}")
plt.plot(losses_adam, label='batch cost')
plt.plot(losses_rms, label='RMSProp cost')
plt.legend()
plt.show()
def main():
max_iter = 20 # make 30 for sigmoid
print_period = 10
X, Y = get_normalized_data()
lr = 0.00004
reg = 0.01
Xtrain = X[:-1000,]
Ytrain = Y[:-1000]
Xtest = X[-1000:,]
Ytest = Y[-1000:]
N, D = Xtrain.shape
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
batch_sz = 500
n_batches = N / batch_sz
M = 300
K = 10
W1 = np.random(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
# 1. constant learning rate
LL_batch = []
CR_batch = []
for i in range(max_iter):
for j in range(n_batches):
xBatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),:]
yBatch = Ytrain[j*batch_sz:(j*batch_sz + batch_sz),:]
pYbatch, Z= forward(xBatch, W1, b1, W2, b2)
W1 -= lr*(derivative_w2(Z, yBatch, pYbatch) + reg*W2)
b1 -= lr*(derivative_b2(yBatch, pYbatch) + reg*b2)
W2 -= lr*(derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1)
b2 -= lr*(derivative_b1(Z, yBatch, pYbatch, W2) + reg*b1)
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_batch.append(ll)
print("Cost at iteration i=%d, j=%d: %.6f", % (i, j, ll))
err = error_rate(pY, Ytest)
CR_batch.append(err)
print("Error rate:", err)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print()"Final error rate:", error_rate(pY, Ytest))
# 2. RMS prop
W1 = np.random(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
LL_rms = []
CR_rms = []
lr0 = 0.001 # if too high, will result with NaN
cache_W2 = 0
cache_b2 = 0
cache_W1 = 0
cache_b1 = 0
decay_rate = 0.999
eps = 0.0000000001
for i in range(max_iter):
for j in range(n_batches):
xBatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),:]
yBatch = Ytrain[j*batch_sz:(j*batch_sz + batch_sz),:]
pYbatch, Z= forward(xBatch, W1, b1, W2, b2)
# updates
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg*W2
cache_W2 = decay_rate*cache_W2 + (1 - decay_rate)*gW2*gW2
W2 -= lr0 * gW2 / (np.sqrt(cache_W2) + eps)
gb2 = derivative_b2(Ybatch, pYbatch) + reg*b2
cache_b2 = decay_rate*cache_b2 + (1 - decay_rate)*gb2*gb2
b2 -= lr0 * gb2 / (np.sqrt(cache_b2) + eps)
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1
cache_W1 = decay_rate*cache_W1 + (1 - decay_rate)*gW1*gW1
W1 -= lr0 * gW1 / (np.sqrt(cache_W1) + eps)
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1
cache_b1 = decay_rate*cache_b1 + (1 - decay_rate)*gb1*gb1
b1 -= lr0 * gb1 / (np.sqrt(cache_b1) + eps)
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_rms.append(ll)
print("Cost at iteration i=%d, j=%d: %.6f", % (i, j, ll))
err = error_rate(pY, Ytest)
CR_rms.append(err)
print("Error rate:", err)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print()"Final error rate:", error_rate(pY, Ytest))
# 3. batch GD w/ Nesterov momentum
W1 = np.random(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
LL_nest = []
CR_nest = []
mu = 0.9
# dW2 = 0
# db2 = 0
# dW1 = 0
# db1 = 0
vW2 = 0
vb2 = 0
vW1 = 0
vb1 = 0
for i in range(max_iter):
for j in range(n_batches):
# because we want g(t) = grad(f(W(t-1) - lr*mu*dW(t-1)))
# dW(t) = mu*dW(t-1) + g(t)
# W(t) = W(t-1) - mu*dW(t)
W1_tmp = W1 - lr*mu*vW1
b1_tmp = b1 - lr*mu*vb1
W2_tmp = W2 - lr*mu*vW2
b2_tmp = b2 - lr*mu*vb2
xBatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),:]
yBatch = Ytrain[j*batch_sz:(j*batch_sz + batch_sz),:]
pYbatch, Z= forward(xBatch, W1_tmp, b1_tmp, W2_tmp, b2_tmp)
# updates
vW2 = mu*vW2 + derivative_w2(Z, Ybatch, pYbatch) + reg*W2_tmp
W2 -= lr*vW2
vb2 = mu*vb2 + derivative_b2(Ybatch, pYbatch) + reg*b2_tmp
b2 -= lr*vb2
vW1 = mu*vW1 + derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2_tmp) + reg*W1_tmp
W1 -= lr*vW1
vb1 = mu*vb1 + derivative_b1(Z, Ybatch, pYbatch, W2_tmp) + reg*b1_tmp
b1 -= lr*vb1
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_nest.append(ll)
print("Cost at iteration i=%d, j=%d: %.6f", % (i, j, ll))
err = error_rate(pY, Ytest)
CR_nest.append(err)
print("Error rate:", err)
pY, _ = forward(Xtest, W1, b1, W2, b2)
print()"Final error rate:", error_rate(pY, Ytest))
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 # make it 30 for sigmoid
print_period = 10
X, Y = get_normalized_data()
lr = 0.00004
reg = 0.01
Xtrain = X[:-1000,]
Ytrain = Y[:-1000]
Xtest = X[-1000:,]
Ytest = Y[-1000:]
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
batch_sz = 500
n_batches = N / batch_sz
M = 300
K = 10
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
# 1. const
# cost = -16
LL_batch = []
CR_batch = []
for i in xrange(max_iter):
for j in xrange(n_batches):
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# print "first batch cost:", cost(pYbatch, Ybatch)
# updates
W2 -= lr*(derivative_w2(Z, Ybatch, pYbatch) + reg*W2)
b2 -= lr*(derivative_b2(Ybatch, pYbatch) + reg*b2)
W1 -= lr*(derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1)
b1 -= lr*(derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1)
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_batch.append(ll)
print "Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll)
err = error_rate(pY, Ytest)
CR_batch.append(err)
print "Error rate:", err
pY, _ = forward(Xtest, W1, b1, W2, b2)
print "Final error rate:", error_rate(pY, Ytest)
# 2. RMSprop
W1 = np.random.randn(D, M) / 28
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
LL_rms = []
CR_rms = []
lr0 = 0.001 # if you set this too high you'll get NaN!
cache_W2 = 0
cache_b2 = 0
cache_W1 = 0
cache_b1 = 0
decay_rate = 0.999
eps = 0.0000000001
for i in xrange(max_iter):
for j in xrange(n_batches):
Xbatch = Xtrain[j*batch_sz:(j*batch_sz + batch_sz),]
Ybatch = Ytrain_ind[j*batch_sz:(j*batch_sz + batch_sz),]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
# print "first batch cost:", cost(pYbatch, Ybatch)
# updates
gW2 = derivative_w2(Z, Ybatch, pYbatch) + reg*W2
cache_W2 = decay_rate*cache_W2 + (1 - decay_rate)*gW2*gW2
W2 -= lr0 * gW2 / (np.sqrt(cache_W2) + eps)
gb2 = derivative_b2(Ybatch, pYbatch) + reg*b2
cache_b2 = decay_rate*cache_b2 + (1 - decay_rate)*gb2*gb2
b2 -= lr0 * gb2 / (np.sqrt(cache_b2) + eps)
gW1 = derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg*W1
cache_W1 = decay_rate*cache_W1 + (1 - decay_rate)*gW1*gW1
W1 -= lr0 * gW1 / (np.sqrt(cache_W1) + eps)
gb1 = derivative_b1(Z, Ybatch, pYbatch, W2) + reg*b1
cache_b1 = decay_rate*cache_b1 + (1 - decay_rate)*gb1*gb1
b1 -= lr0 * gb1 / (np.sqrt(cache_b1) + eps)
if j % print_period == 0:
# calculate just for LL
pY, _ = forward(Xtest, W1, b1, W2, b2)
# print "pY:", pY
ll = cost(pY, Ytest_ind)
LL_rms.append(ll)
print "Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll)
err = error_rate(pY, Ytest)
CR_rms.append(err)
print "Error rate:", err
pY, _ = forward(Xtest, W1, b1, W2, b2)
print "Final error rate:", error_rate(pY, Ytest)
plt.plot(LL_batch, label='const')
plt.plot(LL_rms, label='rms')
plt.legend()
plt.show()
eps = 1e-8
# 1. Adam optimizer
loss_adam = []
err_adam = []
t = 1
for i in range(max_iter):
for j in range(n_batch):
X_batch = X_train[j * batch_sz:(j * batch_sz + batch_sz), ]
Y_batch = Y_train_ind[j * batch_sz:(j * batch_sz + batch_sz), ]
pY_batch, Z = forward(X_batch, W1, b1, W2, b2)
# Update the gradiant
gW2 = derivative_w2(Z, Y_batch, pY_batch) + reg * W2
gb2 = derivative_b2(Y_batch, pY_batch) + reg * b2
gW1 = derivative_w1(X_batch, Z, Y_batch, pY_batch, W2) + reg * W1
gb1 = derivative_b1(Z, Y_batch, pY_batch, W2) + reg * b1
# Update new Moments
mW1 = beta1 * mW1 + (1 - beta1) * gW1
mb1 = beta1 * mb1 + (1 - beta1) * gb1
mW2 = beta1 * mW2 + (1 - beta1) * gW2
mb2 = beta1 * mb2 + (1 - beta1) * gb2
# Update new Velocity
vW1 = beta2 * vW1 + (1 - beta2) * gW1 * gW1
vb1 = beta2 * vb1 + (1 - beta2) * gb1 * gb1
vW2 = beta2 * vW2 + (1 - beta2) * gW2 * gW2
vb2 = beta2 * vb2 + (1 - beta2) * gb2 * gb2
def main():
# 1.batch SGD
# 2. batch SGD with momentum
# 3. batch SGD with Nesterov
max_iter = 20
print_period = 10
X, Y = get_normalized_data()
lr = 0.00004
reg = 0.01
Xtrain, Ytrain = X[:-1000], Y[:-1000]
Xtest, Ytest = X[-1000:], Y[-1000:]
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = X.shape
batch_sz = 500
n_batches = N / batch_sz
M = 300 # number of hidden neurons
K = 10 # number of output classes
W1 = np.random.randn(D, M) / np.sqrt(D + M)
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
#1. batch SGD
LL_batch = []
CR_batch = []
for i in xrange(max_iter):
for j in xrange(n_batches):
Xbatch = Xtrain[j * batch_sz:(j + 1) * batch_sz, ]
Ybatch = Ytrain_ind[j * batch_sz:(j + 1) * batch_sz, ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
W2 -= lr * (derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
b2 -= lr * (derivative_b2(Ybatch, pYbatch) + reg * b2)
W1 -= lr * (derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) +
reg * W1)
b1 -= lr * (derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
ll = cost(pY, Ytest_ind)
LL_batch.append(ll)
print "Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll)
err = error_rate(pY, Ytest)
CR_batch.append(err)
print "Error rate:", err
pY, _ = forward(Xtest, W1, b1, W2, b2)
print "Final error rate:", error_rate(pY, Ytest)
#2. batch with momentum
W1 = np.random.randn(D, M) / np.sqrt(D + M)
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
LL_momentum = []
CR_momentum = []
mu = 0.9
dW2 = 0
db2 = 0
dW1 = 0
db1 = 0
for i in xrange(max_iter):
for j in xrange(n_batches):
Xbatch = Xtrain[j * batch_sz:(j + 1) * batch_sz, ]
Ybatch = Ytrain_ind[j * batch_sz:(j + 1) * batch_sz, ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
dW2 = mu * dW2 - lr * (derivative_w2(Z, Ybatch, pYbatch) +
reg * W2)
W2 += dW2
db2 = mu * db2 - lr * (derivative_b2(Ybatch, pYbatch) + reg * b2)
b2 += db2
dW1 = mu * dW1 - lr * (
derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1)
W1 += dW1
db1 = mu * db1 - lr * (derivative_b1(Z, Ybatch, pYbatch, W2) +
reg * b1)
b1 += db1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
ll = cost(pY, Ytest_ind)
LL_momentum.append(ll)
print "Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll)
err = error_rate(pY, Ytest)
CR_momentum.append(err)
print "Error rate:", err
pY, _ = forward(Xtest, W1, b1, W2, b2)
print "Final error rate:", error_rate(pY, Ytest)
#3. batch with Nesterov momentum
W1 = np.random.randn(D, M) / np.sqrt(D + M)
b1 = np.zeros(M)
W2 = np.random.randn(M, K) / np.sqrt(M)
b2 = np.zeros(K)
LL_nesterov = []
CR_nesterov = []
mu = 0.9
dW2 = 0
db2 = 0
dW1 = 0
db1 = 0
for i in xrange(max_iter):
for j in xrange(n_batches):
Xbatch = Xtrain[j * batch_sz:(j + 1) * batch_sz, ]
Ybatch = Ytrain_ind[j * batch_sz:(j + 1) * batch_sz, ]
pYbatch, Z = forward(Xbatch, W1, b1, W2, b2)
dW2 = mu * mu * dW2 - (1 + mu) * lr * (
derivative_w2(Z, Ybatch, pYbatch) + reg * W2)
W2 += dW2
db2 = mu * mu * db2 - (1 + mu) * lr * (
derivative_b2(Ybatch, pYbatch) + reg * b2)
b2 += db2
dW1 = mu * mu * dW1 - (1 + mu) * lr * (
derivative_w1(Xbatch, Z, Ybatch, pYbatch, W2) + reg * W1)
W1 += dW1
db1 = mu * mu * db1 - (1 + mu) * lr * (
derivative_b1(Z, Ybatch, pYbatch, W2) + reg * b1)
b1 += db1
if j % print_period == 0:
pY, _ = forward(Xtest, W1, b1, W2, b2)
ll = cost(pY, Ytest_ind)
LL_nesterov.append(ll)
print "Cost at iteration i=%d, j=%d: %.6f" % (i, j, ll)
err = error_rate(pY, Ytest)
CR_nesterov.append(err)
print "Error rate:", err
pY, _ = forward(Xtest, W1, b1, W2, b2)
print "Final error rate:", error_rate(pY, Ytest)
plt.plot(LL_batch, label="batch")
plt.plot(LL_momentum, label='momentum')
plt.plot(LL_nesterov, label='nesterov')
plt.legend()
plt.show()
def main():
Xtrain, Xtest, Ytrain, Ytest = get_transformed_data()
Ytrain_ind = y2indicator(Ytrain)
Ytest_ind = y2indicator(Ytest)
N, D = Xtrain.shape
M = 300
K = len(set(Ytrain))
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 weights
W1_0 = W1.copy()
b1_0 = b1.copy()
W2_0 = W2.copy()
b2_0 = b2.copy()
lr = 0.00004
reg = 0.01
batch_sz = 500
n_batches = N // batch_sz
epochs = 20
# 1. batch
costs_batch = []
for t in range(epochs):
tmpX, tmpY = shuffle(Xtrain, Ytrain_ind)
for j in range(n_batches):
x = tmpX[j * batch_sz:(j * batch_sz + batch_sz), :]
y = tmpY[j * batch_sz:(j * batch_sz + batch_sz), :]
pY, Z = forward(x, W1, b1, W2, b2)
W2 -= lr * (derivative_W2(Z, pY, y) + reg * W2)
b2 -= lr * (derivative_b2(pY, y) + reg * b2)
W1 -= lr * (derivative_W1(x, W2, Z, pY, y) + reg * W1)
b1 -= lr * (derivative_b1(W2, Z, pY, y) + reg * b1)
if j % 10 == 0:
pY_test, _ = forward(Xtest, W1, b1, W2, b2)
c = cost(pY_test, Ytest_ind)
costs_batch.append(c)
print("Cost at iteration t=%d, j=%d: %.6f" % (t, j, c))
e = error_rate(pY_test, Ytest)
print("Error rate:", e)
print("\n")
# 2. RMSprop
W1 = W1_0.copy()
b1 = b1_0.copy()
W2 = W2_0.copy()
b2 = b2_0.copy()
cache_W2 = 1
cache_b2 = 1
cache_W1 = 1
cache_b1 = 1
decay_rate = 0.999
eps = 1e-10
lr0 = 0.001
costs_RMS = []
for t in range(epochs):
tmpX, tmpY = shuffle(Xtrain, Ytrain_ind)
for j in range(n_batches):
x = tmpX[j * batch_sz:(j * batch_sz + batch_sz), :]
y = tmpY[j * batch_sz:(j * batch_sz + batch_sz), :]
pY, Z = forward(x, W1, b1, W2, b2)
gW2 = (derivative_W2(Z, pY, y) + reg * W2)
cache_W2 = decay_rate * cache_W2 + (1 - decay_rate) * gW2 * gW2
W2 -= lr0 * gW2 / (np.sqrt(cache_W2) + eps)
gb2 = (derivative_b2(pY, y) + reg * b2)
cache_b2 = decay_rate * cache_b2 + (1 - decay_rate) * gb2 * gb2
b2 -= lr0 * gb2 / (np.sqrt(cache_b2) + eps)
gW1 = (derivative_W1(x, W2, Z, pY, y) + reg * W1)
cache_W1 = decay_rate * cache_W1 + (1 - decay_rate) * gW1 * gW1
W1 -= lr0 * gW1 / (np.sqrt(cache_W1) + eps)
gb1 = (derivative_b1(W2, Z, pY, y) + reg * b1)
cache_b1 = decay_rate * cache_b1 + (1 - decay_rate) * gb1 * gb1
b1 -= lr0 * gb1 / (np.sqrt(cache_b1) + eps)
if j % 10 == 0:
pY_test, _ = forward(Xtest, W1, b1, W2, b2)
c = cost(pY_test, Ytest_ind)
costs_RMS.append(c)
print("Cost at iteration t=%d, j=%d: %.6f" % (t, j, c))
e = error_rate(pY_test, Ytest)
print("Error rate:", e)
plt.plot(costs_batch, label="batch")
plt.plot(costs_RMS, label="rms")
plt.legend()
plt.show()