I have previously used a spread sheet to: implement a Runge–Kutta integrator and simulate a pendulum, and implement a back propagation neural network. Both tim

I have previously used a spread sheet to: implement a Runge–Kutta integrator and simulate a pendulum, and implement a back propagation neural network. Both times I had previously tried and failed to implement them in a proper language. Errors were had to debug in a batch process (loss of energy in pendulum, no learning in the NN). Excel/OpenOffice was great for being able to instantly propagate state through N steps, whilst simultaneously debugging the transition function of said state. Once my formulas were correct I translated it to a better language of course.