David Widmann

I just quickly tried an ODE version of your example (replacing `h(...)[i]` in the function with just `u[i]` and using `alg = Tsit5()`) and it fails with the same error...

Sure, in principle it works and is tested here: https://github.com/SciML/DelayDiffEq.jl/blob/bdc2887f755812102533c699afdfadd356c7a155/test/integrators/cache.jl I wonder if it's only supposed to work (by design in OrdinaryDiffEq) for in-place problems though.

@oscardssmith This PR causes a severe regression of the Waltman test problem.

Just copied from Slack for archiving purposes: > So, I think, both approaches would be useful and could be combined since they work differently. First we could base convergence/divergence on...

I don't have access to a computer right now but two initial observations: - I'm wondering if you specified `tstops` and `d_didcontinuities` incorrectly - the name `initTauU` indicates that it...

Hmm.... It seems the provided example errors since `S(t)S(t-tau_ext)` becomes negative and hence it's not possible to compute the square root of this term anymore. I guess that's also the...

Using e.g. `abstol=1e-14, reltol=1e-14` doesn't seem to help, the output is the same (naively I would also assume that the tolerance shouldn't affect the approximation of the value at 0.1...

The problem seems to be `ReverseDiffAdjoint`. Without it I get: ```julia julia> sensitivity(); isapprox(J1, J2; rtol = 0.001) = true isapprox(J1, J3; rtol = 0.001) = true isapprox(J2, J3; rtol...

Yes, hopefully the compiler is smart enough. However, there's another issue: in the same way we have to pass around `integrator` to the `tgrad`, `analytic`, etc. functions (or not). Of...

I'm working on a prototype for `ODEFunction` and I still hope that not too many changes are necessary in OrdinaryDiffEq. However, I'm not sure how to deal with the fact...