Comparing Simulations with Solutions for Classic Differential Equation Models Daniel J. Teague NC School of Science and Mathematics teague@ncssm. edu
Context at NCSSM is a public boarding school 650 11 th and 12 th grade students from every congressional district Trimester Schedule Elective Courses: Mathematical Modeling with Differential Equations Introduction to Complex Systems Structure and Dynamics of Modern Networks Advance Probability Models
Context at NCSSM Graph Theory/Introduction to Proof Combinatorics I & II Number Theory or Group Theory Research in Mathematics
Modeling with Differential Equations One Trimester Course (10 Weeks) Focus on Modeling with Modeling and Interpreting Equations and Solutions: not solving lots of different classes of DE’s Separation of Variables, Integrating Factor, Second Order Equations, Systems of Linear Equations, Numerical Solutions
Coupled Equations Parameters are Probabilities
Infectious Disease Models
Probabilistic Model in Deterministic Form What does this equation say about Probability? How can we interpret and model the probability parameter k?
With N in the population, we have… Solve using separation of variables and partial fractions
How do we check the solution? Does our solution satisfy the differential equation? Does our solution model our observations?
What are we really modeling in this problem?
Physical Simulation Take class into the hall, give each students a die, and meet and infect each other with the appropriate probabilities.
But if we did the experiment again, we would have the same solution, but different data. How different? Let’s milk this problem for a couple of days.
Netlogo Simulations
How in well does our Differential Equation do in capturing what we see? If we have the data, do we solve the equation or fit a model to the data?
What do you see in the data vs the solution model
If we slide the model forward 3 ticks…
Suppose we had only the data? How should we estimate the parameter values?
Fit a Logistic Model to the Data
Residual Plot
DE vs LS
How does the Simulation Change if we use an SIR model instead?
Netlogo
Daniel J. Teague NC School of Science and Mathematics teague@ncssm. edu