def train(
model: SoftmaxModel,
datasets: typing.List[np.ndarray],
num_epochs: int,
learning_rate: float,
batch_size: int,
# Task 3 hyperparameters,
use_shuffle: bool,
use_momentum: bool,
momentum_gamma: float):
X_train, Y_train, X_val, Y_val, X_test, Y_test = datasets
# Utility variables
num_batches_per_epoch = X_train.shape[0] // batch_size
num_steps_per_val = num_batches_per_epoch // 5
# Tracking variables to track loss / accuracy
train_loss = {}
val_loss = {}
train_accuracy = {}
val_accuracy = {}
if use_momentum:
learning_rate = 0.02
global_step = 0
for epoch in range(num_epochs):
for step in range(num_batches_per_epoch):
start = step * batch_size
end = start + batch_size
X_batch, Y_batch = X_train[start:end], Y_train[start:end]
# Track train / validation loss / accuracy
# every time we progress 20% through the dataset
prev_grads = model.grads
outputs = model.forward(X_batch)
model.backward(X_batch, outputs, Y_batch)
for i in range(len(model.ws)):
if use_momentum:
model.ws[i] = model.ws[i] - learning_rate * (model.grads[i] + momentum_gamma * prev_grads[i])
else:
model.ws[i] = model.ws[i] - learning_rate * model.grads[i]
if (global_step % num_steps_per_val) == 0:
_val_loss = cross_entropy_loss(Y_val, model.forward(X_val))
val_loss[global_step] = _val_loss
_train_loss = cross_entropy_loss(Y_train, model.forward(X_train))
train_loss[global_step] = _train_loss
train_accuracy[global_step] = calculate_accuracy(
X_train, Y_train, model)
val_accuracy[global_step] = calculate_accuracy(
X_val, Y_val, model)
global_step += 1
# shuffle training examples after each epoch
if use_shuffle:
X_train, Y_train = unison_shuffled_copies(X_train, Y_train)
return model, train_loss, val_loss, train_accuracy, val_accuracy
def train(
num_epochs: int,
learning_rate: float,
batch_size: int,
l2_reg_lambda: float # Task 3 hyperparameter. Can be ignored before this.
):
"""
Function that implements logistic regression through mini-batch
gradient descent for the given hyperparameters
"""
global X_train, X_val, X_test
# Utility variables
num_batches_per_epoch = X_train.shape[0] // batch_size
num_steps_per_val = num_batches_per_epoch // 5
train_loss = {}
val_loss = {}
train_accuracy = {}
val_accuracy = {}
model = BinaryModel(l2_reg_lambda)
if X_train.shape[1] == 784:
X_train = pre_process_images(X_train)
if X_test.shape[1] == 784:
X_test = pre_process_images(X_test)
if X_val.shape[1] == 784:
X_val = pre_process_images(X_val)
global_step = 0
for epoch in range(num_epochs):
for step in range(num_batches_per_epoch):
# Select our mini-batch of images / labels
start = step * batch_size
end = start + batch_size
X_batch, Y_batch = X_train[start:end], Y_train[start:end]
y_hat = model.forward(X_batch)
model.backward(X_batch, y_hat, Y_batch)
model.w += -1 * learning_rate * model.grad
# Track training loss continuously
_train_loss = cross_entropy_loss(Y_batch, y_hat)
train_loss[global_step] = _train_loss
# Track validation loss / accuracy every time we progress 20% through the dataset
if global_step % num_steps_per_val == 0:
_val_loss = cross_entropy_loss(Y_val, model.forward(X_val))
val_loss[global_step] = _val_loss
train_accuracy[global_step] = calculate_accuracy(
X_train, Y_train, model)
val_accuracy[global_step] = calculate_accuracy(
X_val, Y_val, model)
global_step += 1
return model, train_loss, val_loss, train_accuracy, val_accuracy
def train(
model: SoftmaxModel,
datasets: typing.List[np.ndarray],
num_epochs: int,
learning_rate: float,
batch_size: int,
# Task 3 hyperparameters,
use_shuffle: bool,
use_momentum: bool,
momentum_gamma: float):
X_train, Y_train, X_val, Y_val, X_test, Y_test = datasets
# Utility variables
num_batches_per_epoch = X_train.shape[0] // batch_size
num_steps_per_val = num_batches_per_epoch // 5
# Tracking variables to track loss / accuracy
train_loss = {}
val_loss = {}
train_accuracy = {}
val_accuracy = {}
global_step = 0
for epoch in range(num_epochs):
for step in range(num_batches_per_epoch):
start = step * batch_size
end = start + batch_size
X_batch, Y_batch = X_train[start:end], Y_train[start:end]
# Track train / validation loss / accuracy
# every time we progress 20% through the dataset
outputs = model.forward(X_batch)
model.backward(X_batch, outputs, Y_batch)
# update weigths
model.ws[-1] = model.ws[-1] - learning_rate * model.grads[-1]
model.ws[-2] = model.ws[-2] - learning_rate * model.grads[-2]
if (global_step % num_steps_per_val) == 0:
_outputs_train = model.forward(X_train)
_train_loss = cross_entropy_loss(Y_train, _outputs_train)
train_loss[global_step] = _train_loss
_outputs_val = model.forward(X_val)
_val_loss = cross_entropy_loss(Y_val, _outputs_val)
val_loss[global_step] = _val_loss
train_accuracy[global_step] = calculate_accuracy(
X_train, Y_train, model)
val_accuracy[global_step] = calculate_accuracy(
X_val, Y_val, model)
global_step += 1
return model, train_loss, val_loss, train_accuracy, val_accuracy
def train_step(self, X_batch: np.ndarray, Y_batch: np.ndarray):
"""
Perform forward, backward and gradient descent step here.
The function is called once for every batch (see trainer.py) to perform the train step.
The function returns the mean loss value which is then automatically logged in our variable self.train_history.
Args:
X: one batch of images
Y: one batch of labels
Returns:
loss value (float) on batch
"""
logits = self.model.forward(X_batch)
self.model.backward(X_batch, logits, Y_batch)
loss = cross_entropy_loss(Y_batch, logits)
# updating weights
if self.use_momentum:
self.model.momentum_update_weights(self.learning_rate,
self.momentum_grads)
self.momentum_grads = self.momentum_gamma * self.model.grads.copy()
else:
self.model.update_weights(self.learning_rate)
return loss
def train_step(self, X_batch: np.ndarray, Y_batch: np.ndarray):
"""
Perform forward, backward and gradient descent step here.
The function is called once for every batch (see trainer.py) to perform the train step.
The function returns the mean loss value which is then automatically logged in our variable self.train_history.
Args:
X: one batch of images
Y: one batch of labels
Returns:
loss value (float) on batch
"""
# TODO: Implement this function (task 2c)
model = self.model
logits = model.forward(X_batch)
model.backward(X_batch, logits, Y_batch)
if (self.use_momentum):
for i, grad in enumerate(model.grads):
model.ws[i] -= self.learning_rate * self.previous_grads[i]
self.previous_grads[
i] = grad + self.momentum_gamma * self.previous_grads[i]
else:
for i, grad in enumerate(model.grads):
model.ws[i] -= self.learning_rate * grad
loss = cross_entropy_loss(Y_batch, logits) # sol
return loss
def train_step(self, X_batch: np.ndarray, Y_batch: np.ndarray):
"""
Perform forward, backward and gradient descent step here.
The function is called once for every batch (see trainer.py) to perform the train step.
The function returns the mean loss value which is then automatically logged in our variable self.train_history.
Args:
X: one batch of images
Y: one batch of labels
Returns:
loss value (float) on batch
"""
# TODO: Implement this function (task 2c)
dw_1 = 0
dw_2 = 0
logits = self.model.forward(X_batch)
self.model.backward(X_batch, logits, Y_batch)
if(self.use_momentum):
dw_1 = np.add(self.model.grads[0], self.momentum_gamma * dw_1)
dw_2 = np.add(self.model.grads[1], self.momentum_gamma * dw_2)
self.model.ws[0] = np.add(self.model.ws[0], -self.learning_rate * dw_1)
self.model.ws[1] = np.add(self.model.ws[1], -self.learning_rate * dw_2)
else:
self.model.ws[0] = np.add(self.model.ws[0], -self.learning_rate * self.model.grads[0])
self.model.ws[1] = np.add(self.model.ws[1], -self.learning_rate * self.model.grads[1])
loss = cross_entropy_loss(Y_batch, logits) # sol
return loss
def train_step(self, X_batch: np.ndarray, Y_batch: np.ndarray):
"""
Perform forward, backward and gradient descent step here.
The function is called once for every batch (see trainer.py) to perform the train step.
The function returns the mean loss value which is then automatically logged in our variable self.train_history.
Args:
X: one batch of images
Y: one batch of labels
Returns:
loss value (float) on batch
"""
# TODO: Implement this function (task 2b)
# Forward step (retrieving the predictions)
outputs = self.model.forward(X_batch)
# Backward step
self.model.backward(X_batch, outputs, Y_batch)
# Updating the weights
self.model.w -= self.model.grad * self.learning_rate
# Computing the loss
loss = cross_entropy_loss(Y_batch, outputs)
return loss
def train_step(self, X_batch: np.ndarray, Y_batch: np.ndarray):
"""
Perform forward, backward and gradient descent step here.
The function is called once for every batch (see trainer.py) to perform the train step.
The function returns the mean loss value which is then automatically logged in our variable self.train_history.
Args:
X: one batch of images
Y: one batch of labels
Returns:
loss value (float) on batch
"""
# TODO: Implement this function (task 2c)
logits = self.model.forward(X_batch)
self.model.backward(X_batch, logits, Y_batch)
# update weights
#self.model.ws = self.model.w - self.learning_rate*self.model.grad
for i in range(len(self.model.ws)):
if (self.use_momentum):
self.model.ws[i] = self.model.ws[i] - (
self.learning_rate * self.model.grads[i] +
self.momentum_gamma * self.previous_grads[i] *
self.learning_rate)
self.previous_grads[i] = self.model.grads[
i] + self.previous_grads[i] * self.momentum_gamma
else:
self.model.ws[i] = self.model.ws[
i] - self.learning_rate * self.model.grads[i]
loss = cross_entropy_loss(Y_batch, logits)
return loss
def train_step(self, X_batch: np.ndarray, Y_batch: np.ndarray):
"""
Perform forward, backward and gradient descent step here.
The function is called once for every batch (see trainer.py) to perform the train step.
The function returns the mean loss value which is then automatically logged in our variable self.train_history.
Args:
X: one batch of images
Y: one batch of labels
Returns:
loss value (float) on batch
"""
# Perform forward pass to get outputs (predictions)
Yhat_batch = self.model.forward(X_batch)
# Perform backward pass to get gradiant
self.model.backward(X_batch, Yhat_batch, Y_batch)
# Update weights in gradiant step
self.model.w = self.model.w - self.learning_rate * self.model.grad
# Calculate cross entropy loss
loss = cross_entropy_loss(Y_batch, Yhat_batch)
return loss
def train_step(self, X_batch: np.ndarray, Y_batch: np.ndarray):
"""
Perform forward, backward and gradient descent step here.
The function is called once for every batch (see trainer.py) to perform the train step.
The function returns the mean loss value which is then automatically logged in our variable self.train_history.
Args:
X: one batch of images
Y: one batch of labels
Returns:
loss value (float) on batch
"""
# TODO: Implement this function (task 2c)
outputs = self.model.forward(X_batch)
self.model.backward(X_batch, outputs, Y_batch)
if self.use_momentum:
for i in range(len(self.model.ws)):
# Momentum implementation was a bit unclear in assignment, but from Piazza question @115 I assume this is correct
self.momentum[i] = self.previous_grads[
i] + self.momentum_gamma * self.momentum[i]
self.model.ws[i] = self.model.ws[
i] - self.learning_rate * self.momentum[i]
else:
for i in range(len(self.model.ws)):
self.model.ws[i] = self.model.ws[
i] - self.learning_rate * self.model.grads[i]
self.previous_grads = np.copy(self.model.grads)
return cross_entropy_loss(Y_batch, outputs)
def train_step(self, X_batch: np.ndarray, Y_batch: np.ndarray):
"""
Perform forward, backward and gradient descent step here.
The function is called once for every batch (see trainer.py) to perform the train step.
The function returns the mean loss value which is then automatically logged in our variable self.train_history.
Args:
X: one batch of images
Y: one batch of labels
Returns:
loss value (float) on batch
"""
# TODO: Implement this function (task 2c)
loss = 0
output = self.model.forward(X_batch)
self.model.backward(X_batch, output, Y_batch)
#if without momentum do gradient step of approperiate weight, otherwise do momentum gradient step:
if not self.use_momentum:
for i, grad in zip(range(len(self.model.ws)), self.model.grads):
self.model.ws[i] = self.model.ws[i] - self.learning_rate * grad
else:
for i, grad in zip(range(len(self.model.ws)), self.model.grads):
self.vs[i] = grad + self.momentum_gamma * self.vs[i]
self.model.ws[
i] = self.model.ws[i] - self.learning_rate * self.vs[i]
loss = cross_entropy_loss(Y_batch, output)
return loss
def train_and_evaluate(
neurons_per_layer: int,
datasets: typing.List[np.ndarray],
num_epochs: int,
learning_rate: float,
batch_size: int,
# Task 3 hyperparameters,
use_shuffle: bool,
use_improved_sigmoid: bool,
use_improved_weight_init: bool,
use_momentum: bool,
momentum_gamma: float,
use_shift=False):
model = SoftmaxModel(neurons_per_layer, use_improved_sigmoid,
use_improved_weight_init)
model, train_loss, val_loss, train_accuracy, val_accuracy = train(
model,
datasets,
num_epochs=num_epochs,
learning_rate=learning_rate,
batch_size=batch_size,
use_shuffle=use_shuffle,
use_momentum=use_momentum,
momentum_gamma=momentum_gamma,
use_shift=use_shift)
print("----------", use_shuffle, use_improved_sigmoid,
use_improved_weight_init, use_momentum, momentum_gamma, "----------")
print("Final Train Cross Entropy Loss:",
cross_entropy_loss(Y_train, model.forward(X_train)))
print("Final Validation Cross Entropy Loss:",
cross_entropy_loss(Y_val, model.forward(X_val)))
print("Final Test Cross Entropy Loss:",
cross_entropy_loss(Y_test, model.forward(X_test)))
print("Final Train accuracy:", calculate_accuracy(X_train, Y_train, model))
print("Final Validation accuracy:",
calculate_accuracy(X_val, Y_val, model))
print("Final Test accuracy:", calculate_accuracy(X_test, Y_test, model))
return train_loss, val_loss, train_accuracy, val_accuracy
def validation_step(self):
"""
Perform a validation step to evaluate the model at the current step for the validation set.
Also calculates the current accuracy of the model on the train set.
Returns:
loss (float): cross entropy loss over the whole dataset
accuracy_ (float): accuracy over the whole dataset
Returns:
loss value (float) on batch
"""
# NO NEED TO CHANGE THIS FUNCTION
logits = self.model.forward(self.X_val)
loss = cross_entropy_loss(Y_val, logits)
accuracy_train = calculate_accuracy(X_train, Y_train, self.model)
accuracy_val = calculate_accuracy(X_val, Y_val, self.model)
return loss, accuracy_train, accuracy_val
def train_step(self, X_batch: np.ndarray, Y_batch: np.ndarray):
"""
Perform forward, backward and gradient descent step here.
The function is called once for every batch (see trainer.py) to perform the train step.
The function returns the mean loss value which is then automatically logged in our variable self.train_history.
Args:
X: one batch of images
Y: one batch of labels
Returns:
loss value (float) on batch
"""
out = self.model.forward(X_batch)
self.model.backward(X_batch, out, Y_batch)
self.model.w -= self.model.grad * self.learning_rate
loss = cross_entropy_loss(Y_batch, out)
return loss
def train_step(self, X_batch: np.ndarray, Y_batch: np.ndarray):
"""
Perform forward, backward and gradient descent step here.
The function is called once for every batch (see trainer.py) to perform the train step.
The function returns the mean loss value which is then automatically logged in our variable self.train_history.
Args:
X: one batch of images
Y: one batch of labels
Returns:
loss value (float) on batch
"""
# TODO: Implement this function (task 2c)
loss = 0
loss = cross_entropy_loss(Y_batch, logits) # sol
return loss
def train_step(self, X_batch: np.ndarray, Y_batch: np.ndarray):
"""
Perform forward, backward and gradient descent step here.
The function is called once for every batch (see trainer.py) to perform the train step.
The function returns the mean loss value which is then automatically logged in our variable self.train_history.
Args:
X: one batch of images
Y: one batch of labels
Returns:
loss value (float) on batch
"""
# TODO: Implement this function (task 2b)
y = self.model.forward(X_batch)
self.model.backward(X_batch, y, Y_batch) # compute the gradient
delta_W = self.model.grad
self.model.w = self.model.w - self.learning_rate * delta_W #perform gradient descent step
loss = cross_entropy_loss(Y_batch, y)
return loss
def train_step(self, X_batch: np.ndarray, Y_batch: np.ndarray):
"""
Perform forward, backward and gradient descent step here.
The function is called once for every batch (see trainer.py) to perform the train step.
The function returns the mean loss value which is then automatically logged in our variable self.train_history.
Args:
X: one batch of images
Y: one batch of labels
Returns:
loss value (float) on batch
"""
# Perform forward pass to get outputs (predictions)
Yhat_batch = self.model.forward(X_batch)
# Perform backward pass to get gradiant
self.model.backward(X_batch, Yhat_batch, Y_batch)
if self.use_momentum:
# update delta w (Formula 6)
for layer_idx, grads in enumerate(self.model.grads):
self.previous_grads[
layer_idx] = grads + self.momentum_gamma * self.previous_grads[
layer_idx]
# Update weights in gradiant step with momentum
for layer_idx, previous_grads in enumerate(self.previous_grads):
self.model.ws[layer_idx] = self.model.ws[
layer_idx] - self.learning_rate * previous_grads
else:
# Update weights in gradiant step
for layer_idx, grads in enumerate(self.model.grads):
self.model.ws[layer_idx] = self.model.ws[
layer_idx] - self.learning_rate * grads
# Calculate cross entropy loss
loss = cross_entropy_loss(Y_batch, Yhat_batch)
return loss
def train_step(self, X_batch: np.ndarray, Y_batch: np.ndarray):
"""
Perform forward, backward and gradient descent step here.
The function is called once for every batch (see trainer.py) to perform the train step.
The function returns the mean loss value which is then automatically logged in our variable self.train_history.
Args:
X: one batch of images
Y: one batch of labels
Returns:
loss value (float) on batch
"""
logits = self.model.forward(X_batch)
self.model.backward(X_batch, logits, Y_batch)
for i, w in enumerate(self.model.ws):
if self.use_momentum:
w -= self.previous_grads[i] * self.learning_rate # t
self.previous_grads[i] = self.model.grads[i] + \
self.momentum_gamma*self.previous_grads[i] # t+1
else:
w -= self.model.grads[i] * self.learning_rate
loss = cross_entropy_loss(Y_batch, logits)
return loss
def train_step(self, X_batch: np.ndarray, Y_batch: np.ndarray):
"""
Perform forward, backward and gradient descent step here.
The function is called once for every batch (see trainer.py) to perform the train step.
The function returns the mean loss value which is then automatically logged in our variable self.train_history.
Args:
X: one batch of images
Y: one batch of labels
Returns:
loss value (float) on batch
"""
# TODO: Implement this function (task 2c)
loss = 0
outputs = self.model.forward(X_batch)
self.model.backward(X_batch, outputs, Y_batch)
if (self.use_momentum):
#FIX THIS
self.previous_grads[0] = self.model.grads[
0] + self.momentum_gamma * self.previous_grads[0]
self.previous_grads[1] = self.model.grads[
1] + self.momentum_gamma * self.previous_grads[1]
self.model.ws[0] = self.model.ws[0] - self.learning_rate * (
self.previous_grads[0])
self.model.ws[1] = self.model.ws[1] - self.learning_rate * (
self.previous_grads[1])
else:
self.model.ws[0] = self.model.ws[
0] - self.model.grads[0] * self.learning_rate
self.model.ws[1] = self.model.ws[
1] - self.model.grads[1] * self.learning_rate
loss = cross_entropy_loss(Y_batch, outputs)
return loss
def train(
num_epochs: int,
learning_rate: float,
batch_size: int,
l2_reg_lambda: float # Task 3 hyperparameter. Can be ignored before this.
):
"""
Function that implements logistic regression through mini-batch
gradient descent for the given hyperparameters
"""
global X_train, X_val, X_test
# Utility variables
num_batches_per_epoch = X_train.shape[0] // batch_size
num_steps_per_val = num_batches_per_epoch // 5
train_loss = {}
val_loss = {}
train_accuracy = {}
val_accuracy = {}
model = BinaryModel(l2_reg_lambda, X_train.shape[0])
# initialize weights and outputs
model.w = np.zeros((785, 1))
# for early stopping
is_val_loss_increasing = [False] * num_increases
global_step = 0
for epoch in range(num_epochs):
for step in range(num_batches_per_epoch):
# Select our mini-batch of images / labels
start = step * batch_size
end = start + batch_size
X_batch, Y_batch = X_train[start:end], Y_train[start:end]
# forward and backward pass
output = model.forward(X_batch)
model.backward(X_batch, output, Y_batch)
# update weights
model.w = model.w - learning_rate * model.grad
# Track training loss continuously
output_train = model.forward(X_train)
_train_loss = cross_entropy_loss(Y_train, output_train)
train_loss[global_step] = _train_loss
# Track validation loss / accuracy every time we progress 20% through the dataset
if global_step % num_steps_per_val == 0:
output_val = model.forward(X_val)
_val_loss = cross_entropy_loss(Y_val, output_val)
val_loss[global_step] = _val_loss
train_accuracy[global_step] = calculate_accuracy(
X_train, Y_train, model)
val_accuracy[global_step] = calculate_accuracy(
X_val, Y_val, model)
# early stopping
stopping = False
if with_stopping == True and global_step > 0:
stopping = early_stopping(num_increases,
is_val_loss_increasing, val_loss,
global_step, num_steps_per_val)
if with_stopping == True and stopping is True:
break
global_step += 1
if with_stopping == True and stopping is True:
print('Epoch =', epoch)
break
return model, train_loss, val_loss, train_accuracy, val_accuracy
def train(
model: SoftmaxModel,
datasets: typing.List[np.ndarray],
num_epochs: int,
learning_rate: float,
batch_size: int,
# Task 3 hyperparameters,
use_shuffle: bool,
use_momentum: bool,
use_early_stopping: bool,
momentum_gamma: float):
X_train, Y_train, X_val, Y_val, X_test, Y_test = datasets
# Utility variables
num_batches_per_epoch = X_train.shape[0] // batch_size
num_steps_per_val = num_batches_per_epoch // 5
# Tracking variables to track loss / accuracy
train_loss = {}
val_loss = {}
train_accuracy = {}
val_accuracy = {}
momentum = [0 for i in range(len(model.grads))]
#Variables used for early stopping
mean_val_loss = []
list_val_losses = []
global_loss_counter = 2
global_step = 0
for epoch in range(num_epochs):
# Shuffling before next epoch
if use_shuffle == True:
shuffle_in_unison(X_train, Y_train)
for step in range(num_batches_per_epoch):
start = step * batch_size
end = start + batch_size
X_batch, Y_batch = X_train[start:end], Y_train[start:end]
y_hat = model.forward(X_batch)
model.backward(X_batch, y_hat, Y_batch)
if use_momentum == True:
momentum[0] = (1 - momentum_gamma) * model.grads[
0] + momentum_gamma * momentum[0]
momentum[1] = (1 - momentum_gamma) * model.grads[
1] + momentum_gamma * momentum[1]
model.ws[0] += -1 * learning_rate * (momentum[0])
model.ws[1] += -1 * learning_rate * (momentum[1])
else:
model.ws[0] += -1 * learning_rate * model.grads[0]
model.ws[1] += -1 * learning_rate * model.grads[1]
# Track train / validation loss / accuracy
# every time we progress 20% through the dataset
if (global_step % num_steps_per_val) == 0:
_val_loss = cross_entropy_loss(Y_val, model.forward(X_val))
val_loss[global_step] = _val_loss
_train_loss = cross_entropy_loss(Y_batch, y_hat)
train_loss[global_step] = _train_loss
train_accuracy[global_step] = calculate_accuracy(
X_train, Y_train, model)
val_accuracy[global_step] = calculate_accuracy(
X_val, Y_val, model)
#Early stopping
if use_early_stopping == True:
list_val_losses.append(_val_loss)
if global_loss_counter % 5 == 0:
mean_val_loss.append(np.mean(list_val_losses))
list_val_losses = []
if global_loss_counter % 10 == 0:
if mean_val_loss[0] < mean_val_loss[1]:
return model, train_loss, val_loss, train_accuracy, val_accuracy
mean_val_loss = []
global_loss_counter += 1
global_step += 1
return model, train_loss, val_loss, train_accuracy, val_accuracy
def train(num_epochs: int, learning_rate: float, batch_size: int,
l2_reg_lambda: float):
"""
Function that implements logistic regression through mini-batch
gradient descent for the given hyperparameters
"""
global X_train, X_val, X_test
# Utility variables
num_batches_per_epoch = X_train.shape[0] // batch_size
num_steps_per_val = num_batches_per_epoch // 5
train_loss = {}
val_loss = {}
train_accuracy = {}
val_accuracy = {}
model = BinaryModel(l2_reg_lambda)
global_step = 0
last_val_loss = 1
best_val_loss = 1
best_weights = None
for epoch in range(num_epochs):
for step in range(num_batches_per_epoch):
# Select our mini-batch of images / labels
start = step * batch_size
end = start + batch_size
X_batch, Y_batch = X_train[start:end], Y_train[start:end]
# Forward pass
train_outputs = model.forward(X_batch)
# Backward propagation
model.backward(X_batch, train_outputs, Y_batch)
model.w -= learning_rate * model.grad
# Track training loss continuously
_train_loss = cross_entropy_loss(Y_batch, train_outputs)
train_loss[global_step] = _train_loss
# Track validation loss / accuracy every time we progress 20% through the dataset
if global_step % num_steps_per_val == 0:
val_outputs = model.forward(X_val)
_val_loss = cross_entropy_loss(Y_val, val_outputs)
val_loss[global_step] = _val_loss
train_accuracy[global_step] = calculate_accuracy(
X_train, Y_train, model)
val_accuracy[global_step] = calculate_accuracy(
X_val, Y_val, model)
global_step += 1
# Compute validation loss for early stopping
val_outputs = model.forward(X_val)
_val_loss = cross_entropy_loss(Y_val, val_outputs)
if _val_loss <= best_val_loss:
best_weights = model.w
best_val_loss = _val_loss
if _val_loss > last_val_loss:
model.w = best_weights
break
last_val_loss = _val_loss
return model, train_loss, val_loss, train_accuracy, val_accuracy
X_train, Y_train, X_val, Y_val, X_test, Y_test = utils.load_binary_dataset(
category1, category2, validation_percentage)
# hyperparameters
num_epochs = 50
learning_rate = 0.2
batch_size = 128
l2_reg_lambda = 0
model, train_loss, val_loss, train_accuracy, val_accuracy = train(
num_epochs=num_epochs,
learning_rate=learning_rate,
batch_size=batch_size,
l2_reg_lambda=l2_reg_lambda)
print("Final Train Cross Entropy Loss:",
cross_entropy_loss(Y_train, model.forward(pre_process_images(X_train))))
print("Final Test Entropy Loss:",
cross_entropy_loss(Y_test, model.forward(pre_process_images(X_test))))
print("Final Validation Cross Entropy Loss:",
cross_entropy_loss(Y_val, model.forward(pre_process_images(X_val))))
print("Train accuracy:", calculate_accuracy(X_train, Y_train, model))
print("Validation accuracy:", calculate_accuracy(X_val, Y_val, model))
print("Test accuracy:", calculate_accuracy(X_test, Y_test, model))
# Plot loss
#plt.ylim([0., .4])
utils.plot_loss(train_loss, "Training Loss")
utils.plot_loss(val_loss, "Validation Loss")
plt.legend()
plt.savefig("binary_train_loss.png")
def train(
num_epochs: int,
learning_rate: float,
batch_size: int,
l2_reg_lambda: float # Task 3 hyperparameter. Can be ignored before this.
):
"""
Function that implements logistic regression through mini-batch
gradient descent for the given hyperparameters
"""
global X_train, X_val, X_test, early_stopping_step
# Utility variables
num_batches_per_epoch = X_train.shape[0] // batch_size
num_steps_per_val = num_batches_per_epoch // 5
train_loss = {}
val_loss = {}
train_accuracy = {}
val_accuracy = {}
model = BinaryModel(l2_reg_lambda)
# Early stopping var init
last_loss = INT_MAX
already_failed = 0
global_step = 0
for epoch in range(num_epochs):
for step in range(num_batches_per_epoch):
# Select our mini-batch of images / labels
start = step * batch_size
end = start + batch_size
X_batch, Y_batch = X_train[start:end], Y_train[start:end]
# The mini-batch gradient descent algorithm for m batches and a single epoch.
model.backward(X_batch, model.forward(X_batch), Y_batch)
model.w = model.w - learning_rate * model.grad
# Track training loss continuously
_train_loss = cross_entropy_loss(Y_batch, model.forward(X_batch))
train_loss[global_step] = _train_loss[0, 0]
# Track validation loss / accuracy every time we progress 20% through the dataset
if global_step % num_steps_per_val == 0:
_val_loss = cross_entropy_loss(Y_val, model.forward(X_val))
val_loss[global_step] = _val_loss[0, 0]
train_accuracy[global_step] = calculate_accuracy(
X_train, Y_train, model)
val_accuracy[global_step] = calculate_accuracy(
X_val, Y_val, model)
# Early stopping criteria
if (_val_loss[0, 0] > last_loss and already_failed > 20):
# Stop early
#print("Early stopping kicked in at epoch nr.:",epoch+1)
#return model, train_loss, val_loss, train_accuracy, val_accuracy
if early_stopping_step == 0:
early_stopping_step = global_step
# Means failed this round
elif (_val_loss[0, 0] > last_loss):
already_failed += 1
# The loss improved this round, reset counter
else:
last_loss = _val_loss[0, 0]
already_failed = 0
global_step += 1
return model, train_loss, val_loss, train_accuracy, val_accuracy
model2,
learning_rate,
batch_size,
shuffle_data,
X_train,
Y_train,
X_val,
Y_val,
)
train_history2, val_history2 = trainer2.train(num_epochs)
print("model from 4e")
print("Train accuracy:", calculate_accuracy(X_train, Y_train, model2))
print("Validation accuracy:", calculate_accuracy(X_val, Y_val, model2))
print("Final Validation Cross Entropy Loss:",
cross_entropy_loss(Y_val, model2.forward(X_val)))
#Plotting training/validation - loss/accuracy comparing the two models:
plt.figure(figsize=(20, 12))
plt.subplot(1, 2, 1)
plt.ylim([0., .9])
utils.plot_loss(train_history2["loss"], "Train - 10 hidden layers")
utils.plot_loss(train_history1["loss"], "Train - 2 hidden layers")
utils.plot_loss(train_history["loss"], "Train - 1 hidden layer")
utils.plot_loss(val_history2["loss"], "Validation - 10 hidden layers")
utils.plot_loss(val_history1["loss"], "Validation - 2 hidden layers")
utils.plot_loss(val_history["loss"], "Validation - 1 hidden layer")
#similar legend as accuracy plot:
plt.legend()
plt.xlabel("Number of Training Steps")
plt.ylabel("Training/Validation Loss")
def train(
model: SoftmaxModel,
datasets: typing.List[np.ndarray],
num_epochs: int,
learning_rate: float,
batch_size: int,
# Task 3 hyperparameters,
use_shuffle: bool,
use_momentum: bool,
momentum_gamma: float,
all_tricks=False):
X_train, Y_train, X_val, Y_val, X_test, Y_test = datasets
# Important hyper parameter setting
if use_momentum:
learning_rate = 0.02
# Utility variables
num_batches_per_epoch = X_train.shape[0] // batch_size
num_steps_per_val = num_batches_per_epoch // 5
# Tracking variables to track loss / accuracy
train_loss = {}
val_loss = {}
train_accuracy = {}
val_accuracy = {}
# Early stop variables
early_stopped_weight_j = np.zeros(
(model.ws[0].shape[0], model.ws[0].shape[1]))
early_stopped_weight_k = np.zeros(
(model.ws[1].shape[0], model.ws[1].shape[1]))
early_stop_counter = 0
best_loss = float("inf")
global_step = 0
for epoch in tqdm(range(num_epochs)):
for step in range(num_batches_per_epoch):
start = step * batch_size
end = start + batch_size
X_batch, Y_batch = X_train[start:end], Y_train[start:end]
# Compute the gradient
outputs = model.forward(X_batch)
model.backward(X_batch, outputs, Y_batch)
# Update the weights with or without task3d, momemtum gradient
for layer in range(len(model.neurons_per_layer)):
if use_momentum:
new_weights = model.ws[layer] - learning_rate * model.grads[
layer] + momentum_gamma * model.delta_w[layer]
model.delta_w[layer] = new_weights - model.ws[layer]
model.ws[layer] = new_weights
else:
model.ws[layer] = model.ws[
layer] - learning_rate * model.grads[layer]
# Track train / validation loss / accuracy
# every time we progress 20% through the dataset
if (global_step % num_steps_per_val) == 0:
# Test the validation data on the network
outputs_validation = model.forward(X_val)
_val_loss = cross_entropy_loss(Y_val, outputs_validation)
val_loss[global_step] = _val_loss
# Track training loss over the entire X_Train and not only the current batch
# once every validation epoch
outputs_training = model.forward(X_train)
_train_loss = cross_entropy_loss(Y_train, outputs_training)
train_loss[global_step] = _train_loss
# Track the accuracy
if not all_tricks:
train_accuracy[global_step] = calculate_accuracy(
outputs_training, Y_train, model)
val_accuracy[global_step] = calculate_accuracy(
outputs_validation, Y_val, model)
# Early stop implementation
# If the loss does not reduce compared to best loss, increment counter
# Otherwise, set the counter to 0 and update best loss
if _val_loss >= best_loss:
early_stop_counter += 1
else:
early_stop_counter = 0
best_loss = _val_loss
early_stopped_weight_j = model.ws[0]
early_stopped_weight_k = model.ws[1]
# If 30 times in a row a new best loss was not achieved, stop the program
if early_stop_counter == 30:
print(
"\nThe cross entropy loss for validation data increased too much, thus triggering "
"the early stop at step : " + str(global_step) +
" and epoch : " + str(epoch))
model.ws[0] = early_stopped_weight_j
model.ws[1] = early_stopped_weight_k
return model, train_loss, val_loss, train_accuracy, val_accuracy
global_step += 1
# Task 3a: Shuffle training samples after each epoch
if use_shuffle:
# Use the shuffle function from sklearn
X_train, Y_train = shuffle(X_train, Y_train)
return model, train_loss, val_loss, train_accuracy, val_accuracy
def train(
model: SoftmaxModel,
datasets: typing.List[np.ndarray],
num_epochs: int,
learning_rate: float,
batch_size: int,
# Task 3 hyperparameters,
use_shuffle: bool,
use_momentum: bool,
momentum_gamma: float):
X_train, Y_train, X_val, Y_val, X_test, Y_test = datasets
# Utility variables
num_batches_per_epoch = X_train.shape[0] // batch_size
num_steps_per_val = num_batches_per_epoch // 5
# Tracking variables to track loss / accuracy
train_loss = {}
val_loss = {}
train_accuracy = {}
val_accuracy = {}
# Early stop variables
early_stopped_weight_j = np.zeros(
(model.ws[0].shape[0], model.ws[0].shape[1]))
early_stopped_weight_k = np.zeros(
(model.ws[1].shape[0], model.ws[1].shape[1]))
early_stop_counter = 0
best_loss = float("inf")
global_step = 0
for epoch in tqdm(range(num_epochs)):
for step in range(num_batches_per_epoch):
start = step * batch_size
end = start + batch_size
X_batch, Y_batch = X_train[start:end], Y_train[start:end]
outputs = model.forward(X_batch)
model.backward(X_batch, outputs, Y_batch)
# Update the weights
model.ws[0] = model.ws[0] - learning_rate * model.grads[0]
model.ws[1] = model.ws[1] - learning_rate * model.grads[1]
# Track training loss continuously over the entire X_Train and not only the current batch
#outputs_training = model.forward(X_train)
#_train_loss = cross_entropy_loss(Y_batch, outputs)
#train_loss[global_step] = _train_loss
# Track train / validation loss / accuracy
# every time we progress 20% through the dataset
if (global_step % num_steps_per_val) == 0:
# Test the validation data on the network
outputs_validation = model.forward(X_val)
_val_loss = cross_entropy_loss(Y_val, outputs_validation)
val_loss[global_step] = _val_loss
# Track training loss over the entire X_Train and not only the current batch
# once every validation epoch
outputs_training = model.forward(X_train)
_train_loss = cross_entropy_loss(Y_train, outputs_training)
train_loss[global_step] = _train_loss
# Early stop implementation
# If the loss does not reduce compared to best loss, increment counter
# Otherwise, set the counter to 0 and update best loss
if _val_loss >= best_loss:
early_stop_counter += 1
else:
early_stop_counter = 0
best_loss = _val_loss
early_stopped_weight_j = model.ws[0]
early_stopped_weight_k = model.ws[1]
# If 30 times in a row a new best loss was not achieved, stop the program
if early_stop_counter == 30:
print(
"The cross entropy loss for validation data increased too much, thus triggering "
"the early stop at step : " + str(global_step) +
" and epoch : " + str(epoch))
model.ws[0] = early_stopped_weight_j
model.ws[1] = early_stopped_weight_k
return model, train_loss, val_loss, train_accuracy, val_accuracy
train_accuracy[global_step] = calculate_accuracy(
X_train, Y_train, model)
val_accuracy[global_step] = calculate_accuracy(
X_val, Y_val, model)
global_step += 1
return model, train_loss, val_loss, train_accuracy, val_accuracy
def train(
model: SoftmaxModel,
datasets: typing.List[np.ndarray],
num_epochs: int,
learning_rate: float,
batch_size: int,
# Task 3 hyperparameters,
use_shuffle: bool,
use_momentum: bool,
momentum_gamma: float,
use_shift=False):
X_train, Y_train, X_val, Y_val, X_test, Y_test = datasets
# Utility variables
num_batches_per_epoch = X_train.shape[0] // batch_size
num_steps_per_val = num_batches_per_epoch // 5
# Tracking variables to track loss / accuracy
train_loss = {}
val_loss = {}
train_accuracy = {}
val_accuracy = {}
#Variables for early stopping
last_val_loss = 1
best_val_loss = 1
best_weights = None
increased_last_time = False
# Store last weights update term for momentum
last_weights_update = []
for l in range(len(model.ws)):
last_weights_update.append(np.zeros_like(model.ws[l]))
global_step = 0
for epoch in range(num_epochs):
print("Epoch:", epoch)
for step in range(num_batches_per_epoch):
shift = np.random.randint(low=-2, high=3, size=batch_size)
start = step * batch_size
end = start + batch_size
X_batch, Y_batch = X_train[start:end], Y_train[start:end]
X_local = X_batch
if use_shift:
X_local = np.roll(X_batch[:, :784], shift, axis=1)
ones = np.ones((X_local.shape[0], 1))
X_local = np.concatenate((X_local, ones), axis=1)
train_output = model.forward(X_batch)
model.backward(X_batch, train_output, Y_batch)
for l in range(len(model.ws)):
if use_momentum:
update_term = momentum_gamma * last_weights_update[
l] - learning_rate * model.grads[l]
model.ws[l] += update_term
last_weights_update[l] = update_term
else:
model.ws[l] -= learning_rate * model.grads[l]
# Track train / validation loss / accuracy
# every time we progress 20% through the dataset
if (global_step % num_steps_per_val) == 0:
val_output = model.forward(X_val)
_val_loss = cross_entropy_loss(Y_val, val_output)
val_loss[global_step] = _val_loss
train_output = model.forward(X_train)
_train_loss = cross_entropy_loss(Y_train, train_output)
train_loss[global_step] = _train_loss
train_accuracy[global_step] = calculate_accuracy(
X_train, Y_train, model)
val_accuracy[global_step] = calculate_accuracy(
X_val, Y_val, model)
global_step += 1
# In order to keep labels in the right order, we shuffle an array of indices
# and then apply this ordering to both inputs and labels
if use_shuffle:
indices = np.arange(X_train.shape[0])
np.random.shuffle(indices)
X_train = X_train[indices]
Y_train = Y_train[indices]
# Compute validation loss for early stopping
val_outputs = model.forward(X_val)
_val_loss = cross_entropy_loss(Y_val, val_outputs)
if _val_loss <= best_val_loss:
best_weights = model.ws
best_val_loss = _val_loss
if _val_loss > last_val_loss:
if increased_last_time:
model.ws = best_weights
break
else:
increased_last_time = True
else:
increased_last_time = False
last_val_loss = _val_loss
return model, train_loss, val_loss, train_accuracy, val_accuracy
# ANY PARTS OF THE CODE BELOW THIS CAN BE CHANGED.
# Intialize model
model = BinaryModel()
# Train model
trainer = LogisticTrainer(
model, learning_rate, batch_size, shuffle_dataset,
early_stopping, X_train, Y_train, X_val, Y_val,
)
train_history, val_history = trainer.train(num_epochs)
# Plot and print everything you want of information
print("Final Train Cross Entropy Loss:",
cross_entropy_loss(Y_train, model.forward(X_train)))
print("Final Validation Cross Entropy Loss:",
cross_entropy_loss(Y_val, model.forward(X_val)))
print("Train accuracy:", calculate_accuracy(X_train, Y_train, model))
print("Validation accuracy:", calculate_accuracy(X_val, Y_val, model))
# Plot loss for first model (task 2b)
plt.ylim([0., .2])
utils.plot_loss(train_history["loss"],
"Training Loss", npoints_to_average=10)
utils.plot_loss(val_history["loss"], "Validation Loss")
plt.legend()
plt.xlabel("Number of Training Steps")
plt.ylabel("Cross Entropy Loss - Average")
plt.savefig("task2b_binary_train_loss.png")
plt.show()
learning_rate,
batch_size,
shuffle_data,
X_train,
Y_train,
X_val,
Y_val,
)
train_history_naked, val_history_naked = trainer_naked.train(num_epochs)
print("just basic")
print("Train accuracy:", calculate_accuracy(X_train, Y_train, model_naked))
print("Validation accuracy:", calculate_accuracy(X_val, Y_val,
model_naked))
print("Final Validation Cross Entropy Loss:",
cross_entropy_loss(Y_val, model_naked.forward(X_val)))
print("Final Train Cross Entropy Loss:",
cross_entropy_loss(Y_train, model_naked.forward(X_train)))
######1nd model - improved weights######
use_improved_sigmoid = False
use_improved_weight_init = True
use_momentum = False
model = SoftmaxModel(neurons_per_layer, use_improved_sigmoid,
use_improved_weight_init)
trainer = SoftmaxTrainer(
momentum_gamma,
use_momentum,
model,
learning_rate,
batch_size,