# OrdinaryDiffEq.jl: DiscreteCallback at last step
**URL:** https://discourse.julialang.org/t/ordinarydiffeq-jl-discretecallback-at-last-step/46795
**Category:** General Usage
**Tags:** question
**Created:** [September 17, 2020, 5:26pm UTC](https://discourse.julialang.org/t/ordinarydiffeq-jl-discretecallback-at-last-step/46795 "2020-09-17T17:26:05Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@ranocha](https://discourse.julialang.org/u/ranocha)
#### Post date: [September 17, 2020, 5:26pm UTC](https://discourse.julialang.org/t/ordinarydiffeq-jl-discretecallback-at-last-step/46795/1 "2020-09-17T17:26:06Z")
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.
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### Author:  [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)
#### Post date: [September 17, 2020, 5:56pm UTC](https://discourse.julialang.org/t/ordinarydiffeq-jl-discretecallback-at-last-step/46795/2 "2020-09-17T17:56:44Z")
you can do `other_condition || t == integrator.prob.tspan[2]`
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### Author:  [@ranocha](https://discourse.julialang.org/u/ranocha)
#### Post date: [September 17, 2020, 6:13pm UTC](https://discourse.julialang.org/t/ordinarydiffeq-jl-discretecallback-at-last-step/46795/3 "2020-09-17T18:13:18Z")
Thanks, Chris!
> [@ChrisRackauckas](#):
>
> t == integrator.prob.tspan[2]
That’s along the lines of what I’ve tried (and used in the past, if I remember correctly). However, I get
```julia
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
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### Author:  [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)
#### Post date: [September 17, 2020, 6:19pm UTC](https://discourse.julialang.org/t/ordinarydiffeq-jl-discretecallback-at-last-step/46795/4 "2020-09-17T18:19:54Z")
`integrator.sol.prob.tspan[2]`
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### Author:  [@ranocha](https://discourse.julialang.org/u/ranocha)
#### Post date: [September 17, 2020, 6:22pm UTC](https://discourse.julialang.org/t/ordinarydiffeq-jl-discretecallback-at-last-step/46795/5 "2020-09-17T18:22:11Z")
Thanks! 🤦♂️I’ve forgotten the `.sol`. At least I don’t feel completely stupid since we made the same error at first 😉