OrdinaryDiffEq.jl: DiscreteCallback at last step

General Usage
1

Is there an easy way to determine whether a DiscreteCallback is called after the last step of an integration, i.e. just before the integration terminates? I would like to call such a callback using my chosen condition(u,t,integrator) but also when this step is the last.

2

you can do other_condition || t == integrator.prob.tspan[2]

3

Thanks, Chris!

That’s along the lines of what I’ve tried (and used in the past, if I remember correctly). However, I get

julia> using OrdinaryDiffEq, DiffEqCallbacks

julia> ode = ODEProblem((u,p,t) -> -u, 1.0, (0.0, 1.0))
ODEProblem with uType Float64 and tType Float64. In-place: false
timespan: (0.0, 1.0)
u0: 1.0

julia> cb = DiscreteCallback(
           (u, t, integrator) -> t == integrator.prob.tspan[2],
           (integrator) -> println("Last step"))
DiscreteCallback{var"#3#5",var"#4#6",typeof(DiffEqBase.INITIALIZE_DEFAULT)}(var"#3#5"(), var"#4#6"(), DiffEqBase.INITIALIZE_DEFAULT, Bool[1, 1])

julia> solve(ode, Tsit5(), callback=cb);
ERROR: type ODEIntegrator has no field prob

I’m using

  • Julia v1.5.1
  • DiffEqCallbacks v2.14.1
  • OrdinaryDiffEq v5.42.8
4

integrator.sol.prob.tspan[2]

5

Thanks! :man_facepalming:I’ve forgotten the .sol. At least I don’t feel completely stupid since we made the same error at first :wink: