Differential equations play a crucial role in modeling natural phenomena.
In epidemiological studies, they help describe changes in the populations of susceptible, infected, and recovered individuals over time.In the SIR model, we use a system of differential equations:
- \(S' = -\beta SI\)
- \(I' = \beta SI - \gamma I\)
- \(R' = \gamma I\)
These equations indicate how each group interacts over time.
The susceptible population diminishes as people move to the infected category, then eventually to the recovered category.
The model assumes parameters \( \beta \), the transmission rate, and \( \gamma \), the recovery rate, are constants that determine the speed of these transitions.To solve these equations numerically in a spreadsheet model, we utilize a difference scheme.
Instead of looking at continuous rates of change, which is what differential equations inherently describe, we approximate by calculating differences from day to day.
This approach offers a discrete stepwise insight into how the disease affects a population over time.