# How to perform practical identifiability in Julia?

**URL:** <https://discourse.julialang.org/t/how-to-perform-practical-identifiability-in-julia/121671>\
**Category:** Modelling & Simulations\
**Created:** [October 23, 2024, 8:01pm UTC](https://discourse.julialang.org/t/how-to-perform-practical-identifiability-in-julia/121671 "2024-10-23T20:01:29Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Nick1](https://avatars.discourse-cdn.com/v4/letter/n/47e85d/32.png) [@Nick1](https://discourse.julialang.org/u/Nick1)\
**Post date:** [October 23, 2024, 8:01pm UTC](https://discourse.julialang.org/t/how-to-perform-practical-identifiability-in-julia/121671/1 "2024-10-23T20:01:29Z")

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Is there a way to perform practical identifiability in Julia? I have a systems biology problem with limited data and want to determine which parameters are practically identifiable.

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**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [October 24, 2024, 4:34am UTC](https://discourse.julialang.org/t/how-to-perform-practical-identifiability-in-julia/121671/2 "2024-10-24T04:34:30Z")

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> **[GitHub - insysbio/LikelihoodProfiler.jl: LikelihoodProfiler is a Julia package for...](https://github.com/insysbio/LikelihoodProfiler.jl)**
>
> LikelihoodProfiler is a Julia package for practical identifiability analysis and confidence intervals evaluation.

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**Author:** ![Nick1](https://avatars.discourse-cdn.com/v4/letter/n/47e85d/32.png) [@Nick1](https://discourse.julialang.org/u/Nick1)\
**Post date:** [October 30, 2024, 1:30am UTC](https://discourse.julialang.org/t/how-to-perform-practical-identifiability-in-julia/121671/3 "2024-10-30T01:30:33Z")

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Thanks! I will look it up. Regarding StructuralIdentifiability.jl I get the following error:

> LoadError: MethodError: no method matching (::Nemo.QQMPolyRing)(::Float64)

probably because I have some non-rational polynomial functions. Is there a way to work around it?

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**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [October 30, 2024, 6:59am UTC](https://discourse.julialang.org/t/how-to-perform-practical-identifiability-in-julia/121671/4 "2024-10-30T06:59:20Z")

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That’s pretty fundamental to the method. It works via differentiable algebras and thus only supports rational functions. It would be good to throw a better error on that.