MIT 6.7960 PS1 Walkthrough: From NumPy MLP to PyTorch Autograd Backprop
Hand-write NumPy MLP + backprop → verify with PyTorch Autograd, fully reproducing OCW HW1 core concepts
Hand-write NumPy MLP + backprop → verify with PyTorch Autograd, fully reproducing OCW HW1 core concepts
Week 5 enters deep learning: perceptron to multi-layer nets, backprop chain rule, loss functions, optimizers, TensorFlow/Keras modeling, CNN conv/pool. Project Traffic trains CNN to classify traffic signs.
A model uses loss to know how wrong it is and gradients to know which direction to adjust. Gradient descent repeats three things: compute loss, compute gradients, update parameters. The learning rate controls step size — too large and you overshoot, too small and training takes forever.
Lecture 12 treats a network as a computation graph: the forward pass stores intermediates, the backward pass propagates upstream gradients, and local linear, activation, and softmax rules compute every parameter gradient efficiently.
Lecture 3 decomposes neural-network training into computation graphs, local derivatives, and the chain rule: the forward pass computes a result; backprop accumulates gradients from the output so every parameter knows how to move.
Chapter 7 decomposes neural networks into composable modules and uses backpropagation and vectorization to explain how deep models can be trained efficiently.
HW5 avoids automatic differentiation so learners must track forward shapes, caches, and backward gradients themselves.