A forward pass, or feedforward step, sends an input through successive neural-network layers to produce an output. Each layer applies weights, biases, and an activation transformation before passing its result onward. section 9.7
Classifying penguins with NumPy
A two-layer network receives four penguin measurements, uses ten hidden units, and produces three class outputs. The forward-pass function evaluates each particle’s parameter vector before PSO compares its loss.







