Fourth-order Runge-Kutta time stepping as an operation graph

You can solve the initial value problem y’=f(y) numerical by discretizing y into individual time steps. Starting with y at time n, Runge-Kutta time stepping algorithm computes y at time n+1 given f(y). Here’s what that looks like in a graph,

RungeKutta4 Graph

This is the same as what’s written algebraically on wikipedia’s entry for RK4.