# DifferentialEquations.jl saving data without redundant calculation of control inputs

**URL:** <https://discourse.julialang.org/t/differentialequations-jl-saving-data-without-redundant-calculation-of-control-inputs/62559>\
**Category:** General Usage\
**Tags:** diffeq\
**Created:** [June 8, 2021, 4:27am UTC](https://discourse.julialang.org/t/differentialequations-jl-saving-data-without-redundant-calculation-of-control-inputs/62559 "2021-06-08T04:27:06Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![iHany](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ihany/32/18151_2.png) [@iHany](https://discourse.julialang.org/u/iHany)\
**Post date:** [June 8, 2021, 2:12pm UTC](https://discourse.julialang.org/t/differentialequations-jl-saving-data-without-redundant-calculation-of-control-inputs/62559/3 "2021-06-08T14:12:38Z")

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Thanks for sharing a nice package!

Can I export some dynamical equations with `@log` from a custom package?  
For example,

```julia
using MyPackage: predefined_dynamics! # with @log k = 1
using SimulationLogs

prob = ODEProblem(predefined_dynamics!, x0, tspan)
sol = solve(prob)
out = get_log(sol)
@show out.k # should be an array filled with 1

```

Sorry for a weird question if I understood incorrectly (I’m not familiar with that package 🙂 ).

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