Published at : 23 Jan 2021
We can solve the SIR equations numerically, one step at a time, using today's values of S, I and R to determine today's rates of change S', I' and R'. From these we can estimate tomorrow's values of S, I and R, which give us tomorrow's values of S', I' and R', and so on. The same method can be used to explore the past as well. The process is somewhat tedious but it's fairly easy to program a computer to do it.