Discrete version of continuous SIR model
I'm working with a SIR infection model, which is
in continuous time, where S, I, and R are the proportion of Susceptible, Infected, and Recovered, respectively.
However, since I am working with fixed-width discrete-time data, I think it would be more appropriate to modify the equations accordingly. I know this is incorrect (based on getting a negative values for and , neither of which should be negative):
Ultimately, I would like to estimate and by doing regression on
or whatever the discrete version is.