Help coding function for compartmental model to allow for ageing

Trying to create a deterministic mathematical model that models birth cohorts (i.e. people born in the same year are modelled individually). Expecting ageing to be exponential. Very new to R. I have adapted from published example but do not know if it is doing what I want it to.

function(times, state, parameters) {
a= c(1/diff(x), 0)
n=length(parameters$a)
x=exp(x)
I=state[1:n]
T=state[2n+1]:[3n]
with(as.list(c(state,parameters)),{
dI <-c(phi, rep(0,n-1)) - gammaI - muI - aI - LTFUI
dT <-gammaI + c(0, a[1:n]T[1:n-1]) - muT - aT - LTFU*T
return(list(c(dI, dT)))
})
}

I would like to know if the example of code above correctly accounts for moving from one-year age group to the next at each one year time step? Any assistance or resources would be greatly appreciated. - Struggling student new to R

The specific question can't be answered in the abstract--without representative data and an algebraic notion of the model to be applied.

In general, it helps to think of R as school algebra writ large, f(x) = y, involving three objects -- the function f itself, the argument(s) x and the result(s), y. A problem in R` programming comes down to designing x and y and then finding or writing one or more functions f to make the transformation.

This is facilitated by tidy data in which each observation is a row and each column is an observation. In your case, each row could be an individual or an age cohort and one or more other variables from which the model f is calculated. The data object then yields a table of results for each individual that must be summarized somehow to be stratified by cohort.

This topic was automatically closed 21 days after the last reply. New replies are no longer allowed.

If you have a query related to it or one of the replies, start a new topic and refer back with a link.

Thank you so much. Your reply was very helpful.