Here we assemble Stock and Flow segments to build a computational model that we evaluate below. github 
//wiki.ralfbarkow.ch/assets/pages/mock-graph-data/composite.html HEIGHT 300
We can turn on and off parts of a large simulation by merging their parts into the composite graph we feed into the simulator.
pages/stock-and-flow-simulator
We run 90 steps, thinking of them as days in a quarter. Then reset to initial conditions and run again.
//wiki.ralfbarkow.ch/assets/pages/mock-graph-data/flow-sim.html
We'll speed this up and plot each run fast enough that you can get a good sense of how the controls interact.
We want to plot a timeseries where the data points shows up as they happen. We'll model this a random walk always from the same starting point. mdn mdn
See World Modeled upon which we might test our own notions of modularity.
Tom Fiddaman's model library. site
Comparison of system dynamics software. wikipedia
The Euler method is a first-order numerical procedure for solving ordinary differential equations with a given initial value. wikipedia