Just don't punish yourself over it. There is more information than anyone could handle. It's really a matter of realizing failure is a part of life. You can not avoid failure, but you can sure handle it.
See the supplimentary material of this paper [1]
They split the I compartment into two, one for the documented infected and one for undocumented infected.
Testing isn't part of the model at all, it operates only on the true numbers of susceptible/infected/recovered. Testing only gives you an idea of what those might be.
That said, it does have the potential to impact the perception of danger to individuals. And perception of danger should influence the β factor the author mentions. Learning that a lot of people have it or a lot of people are dying for example may cause people to take it more seriously, and thus influence β.
I don't think those kinds of exercises will teach you about functional programming... Here's why. You can understand imperative programming as a sequence of operations. But functional programming is more like a composition of transformations. It really requires study because you need to think differently.
I would suggest rewriting the standard library of a functional language.... Read the standard functions on lists, maps, tuples, folds, maps, and reimplement them...
I would ask you questions about Haskell and functional programming, if you get them right it will definitely be a plus, but if you say you know Haskell and can't write basic monads from scratch you are doomed
Elm is quite different from purescript or Haskell... It shares syntax and the purity semantics but its type system is much less expressive (no type classes); no do notation; no monads...
Elm has managed effects and purity, and I had immense satisfaction in using it... Managed effects means that doing http requests and working with DOM events are managed from a runtime and from the point of view of the programmer they are just returning values that describe the effectful actions they want to perform, and any changes to programming state from those actions are apparently as function arguments...
The language has its warts, but I would use it if it were not for the poor project management and support.
