# Extracting the last dt used by solver in DifferentialEquations.jl

**URL:** <https://discourse.julialang.org/t/extracting-the-last-dt-used-by-solver-in-differentialequations-jl/90647>\
**Category:** Numerics\
**Tags:** differentialequation\
**Created:** [November 22, 2022, 2:57pm UTC](https://discourse.julialang.org/t/extracting-the-last-dt-used-by-solver-in-differentialequations-jl/90647 "2022-11-22T14:57:45Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![churli](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/churli/32/22048_2.png) [@churli](https://discourse.julialang.org/u/churli)\
**Post date:** [November 22, 2022, 2:57pm UTC](https://discourse.julialang.org/t/extracting-the-last-dt-used-by-solver-in-differentialequations-jl/90647/1 "2022-11-22T14:57:45Z")

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As per the title, I need to be able to extract the last `dt` used by the ODE solver from DifferentialEquations.jl .  
Since in my specific use case I need to extract it whenever I terminate the solver from a callback, it does not matter if it is not available in the ODESolution, as long as I can maybe extract it from the Integrator and write it somewhere that I can then access externally.

Has anyone already done it or do you have any hints for how to get this `dt`?

Thanks!

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**Author:** ![Oscar\_Smith](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/oscar_smith/32/25343_2.png) [@Oscar\_Smith](https://discourse.julialang.org/u/Oscar_Smith)\
**Post date:** [November 22, 2022, 2:59pm UTC](https://discourse.julialang.org/t/extracting-the-last-dt-used-by-solver-in-differentialequations-jl/90647/2 "2022-11-22T14:59:06Z")

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`sol.t[end]-sol.t[end-1]`?

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**Author:** ![churli](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/churli/32/22048_2.png) [@churli](https://discourse.julialang.org/u/churli)\
**Post date:** [November 22, 2022, 3:11pm UTC](https://discourse.julialang.org/t/extracting-the-last-dt-used-by-solver-in-differentialequations-jl/90647/3 "2022-11-22T15:11:40Z")

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But does the solution contain every timestep by default or just a subset?  
If this is the case, it is very easy and I feel very stupid 🫠  
Cheers!

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**Author:** ![Oscar\_Smith](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/oscar_smith/32/25343_2.png) [@Oscar\_Smith](https://discourse.julialang.org/u/Oscar_Smith)\
**Post date:** [November 22, 2022, 3:13pm UTC](https://discourse.julialang.org/t/extracting-the-last-dt-used-by-solver-in-differentialequations-jl/90647/4 "2022-11-22T15:13:22Z")

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The solution contains every timestep unless `saveat` is used.