Mathematics & Science Learning Center
Computer Laboratory

Applications of Systems of Differential Equations

Epidemiology: The Spread of Disease

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Your graph should look like this:

Look at the picture carefully, remembering that the green graph represents infected people, and the red graph represents susceptibles, and consider the following questions:

• Does the relationship between the two groups meet your expectations?
• Do you notice what is happening on the red graph at the time there is a maximum value on the green graph? Is this realistic?
• Does the fact that the two graphs seem to head towards horizontal asymptotes make physical sense, in fact, what does it mean physically?

Creating a Parametric Graph of Infecteds vs. Susceptibles

Well, we've done this next part before (with the Predator-Prey laboratory.) The command we need to create a parametric graph is:

disease1plot=
   ParametricPlot[{sus1,inf1},
   {t,0,30}, PlotRange->All]

Go do it in Mathematica now!

Let's go look at the parametric graph that you just made...

If you're lost, impatient, want an overview of this laboratory assignment, or maybe even all three, you can click on the compass button on the left to go to the table of contents for this laboratory assignment.