Predictive Coding 2D: Free-Energy Network & Error Console

The 2D companion to the 3D free-energy simulator: the same three-layer hierarchical predictive-coding network — sensory, hidden and top belief layers wired by real weight matrices, performing gradient descent on variational free energy — drawn as a flat, pannable node-and-edge diagram instead of an orbiting 3D scene. A scrolling telemetry chart plots free energy and both prediction-error norms over time, so a surprise injection's spike-and-settle is visible as a curve, not just a colour flash. Sensory precision, prior precision and inference rate sliders drive the exact same update equations as the 3D version; drag or scroll the network panel to inspect any layer up close.