Momentum is an optimizer hyperparameter that carries forward update direction. It accelerates movement when optimization heads toward the target and slows movement when it veers away. Like learning rate, it must be tuned for the problem rather than treated as universally optimal. section 5.2.5
Configure momentum in PyTorch
A logistic-regression neuron uses stochastic gradient descent with momentum 0.001 and learning rate 0.02: `optimizer = SGD(model.parameters(), momentum=0.001, lr=0.02)`. Training repeatedly zeros gradients, computes loss, backpropagates, and calls `optimizer.step()` across 200 epochs.





