PIXELS TRADE · EXPLORE THE ENGINEERING

AI Architecture Lab.

Train a network. Inspect the evidence. Control the actions.

Runs locally in your browserNo account. No data upload.

See a network learn.

A real multilayer perceptron learns to separate synthetic points. Change the architecture and observe the measured results.

Real training · CPU · Float64
Epoch0
Parameters25
Preparing the network…

Inside the network

Click a neuron to inspect it
− negative+ positiveLine width = |weight|

The coloured tiles show each node’s output over the input plane. The output node always uses tanh; colours are scores, not calibrated probabilities.

Output decision surface

Move over the plot
Training loss—
Test loss—
Training accuracy—
Test accuracy—
TrainingTest
What is calculated? Formulas, validation and limits

Node: aⱼ = φ(bⱼ + Σᵢ wᵢⱼaᵢ). Data loss: mean ½(ŷ − y)². Update: θ ← θ − η × mean gradient; regularisation applies to weights, not biases.

Backpropagation and SGD run in a browser worker. The core is adapted from TensorFlow Playground under Apache 2.0. L1 retains its original permanent link-pruning behaviour. The displayed loss excludes the regularisation penalty. Our wrapper flushes incomplete final batches and uses a documented seeded PRNG.

The test set is held out from training, but repeatedly inspecting it while choosing settings makes it an exploration set. A final independent validation is required for a real application. This lab does not train an LLM, diagnose patients or assess regulatory compliance.

The gradient check uses central finite differences on one sample, excluding the regularisation term. At ReLU kinks, the derivative is not defined. A pass validates that check only.