DomainError while solving ODE

[ChrisRackauckas]

@zamk

you mentioned earlier that there is a solution which goes negative and that seems to be the case. However, since this is a biological system, none of the variables should be allowed to go negative.

That’s not the point. You need to allow it to go negative in order to reject the negative solution.

@zamk

Eventually, I added u = max.(0.0,u) in the beginning of the model function and that seems to do the trick. However, I am not sure how correct this approach is.

If you have this with PositiveDomain or isoutofdomain, then it’s correct. Those will force the solution to be positive, but to act they have to allow the solution to go slightly negative to trigger. If you error during that triggering, then it can’t work.