From: Medical image diagnosis based on adaptive Hybrid Quantum CNN
# Pseudo-code for Custom Learning Rate Scheduler with Momentum Calculation |
# Step 1: Define the custom learning rate scheduler |
def custom_lr_scheduler(epoch, initial_lr = 0.01): |
lr_decay = 0.1 |
lr = initial_lr * lr_decay ** epoch |
return lr |
# Step 2: Define a function to calculate momentum based on loss history |
def calculate_momentum(loss_list, current_epoch): |
if current_epoch > = 2: |
loss_t_minus_1 = loss_list[current_epoch—2] |
loss_t = loss_list[current_epoch—1] |
beta = 1.0 |
momentum = beta / (1.0 – np.exp(—(loss_t + loss_t_minus_1)) |
# Optionally, you can set a maximum momentum value (e.g., 0.999) if necessary |
# momentum = min(momentum, 0.999) |
else: |
# Set a default momentum value for the first two epochs |
momentum = 0.9 |
return momentum |
# Step 3: Initialize the list to store loss values |
init_loss = 0.0 |
loss_list = [init_loss] |
# Step 4: Create the model and other necessary variables (not shown in the provided code) |
# Step 5: Main training loop with epochs |
for epoch in range(epochs): |
# Step 5.1: Evaluate the model's loss on the test set and store it in the loss_list |
loss = model.evaluate(x_test, y_test_cat)[0] |
loss_list.append(loss) |
# Step 5.2: Calculate the momentum for the current epoch based on loss history |
momentum = calculate_momentum(loss_list, epoch) |
# Step 5.3: Update the learning rate using the custom learning rate scheduler |
learning_rate = custom_lr_scheduler(epoch) |
# Step 5.5: Perform model training with the current learning rate and momentum |
optimizer = SGD(lr = learning_rate, momentum = momentum, nesterov = False) |
model.compile(optimizer = optimizer, loss = 'categorical_crossentropy', metrics = ['accuracy']) |
model.fit(x_train, y_train_cat, epochs = 1, batch_size = batch_size) |