SIR Model
An SIR model is an epidemiological model that computes the theoretical number of people infected with a contagious illness in a closed population over time. The name
of this class of models derives from the fact that they involve coupled equations
relating the number of susceptible people 
, number of people infected 
, and number of people who have recovered 
. One of the simplest SIR models is the Kermack-McKendrick
model.
The Season 1 episode "Vector" (2005) of the television crime drama NUMB3RS features SIR models.
See also
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References
Callahan, J. "The Spread of a Contagious Illness." http://maven.smith.edu/~callahan/ili/pde.html.
Referenced on Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "SIR Model." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/SIRModel.html