Source:
cs.stanford.edu/people/karpathy/reinforcejs/gridworld_dp.html. If the embedded frame above is blocked by your browser or network, open the link in a new tab.
Dynamic Programming
Dynamic programming on a gridworld (interactive)
Interactive browser demo by Andrej Karpathy showing policy evaluation, policy iteration, and value iteration on a configurable gridworld.
Andrej Karpathy’s ReinforceJS demo runs policy evaluation, policy iteration, and value iteration on a gridworld MDP directly in your browser. Use it as a companion to the algorithm pages above: watch state values propagate with each sweep, see the greedy policy refine, and toggle between evaluation-only and full iteration to feel the difference.