# \#parameters

**URL:** https://discourse.julialang.org/tag/parameters/1072.md

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## [Trouble using ParametricOptInterface when a parameter appears inside a min() expression in JuMP](https://discourse.julialang.org/t/trouble-using-parametricoptinterface-when-a-parameter-appears-inside-a-min-expression-in-jump/133661)

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**Author:** [@leo.ch.97](https://discourse.julialang.org/u/leo.ch.97)\
**Replies:** 2\
**Last updated:** [November 4, 2025, 7:03pm UTC](https://discourse.julialang.org/t/trouble-using-parametricoptinterface-when-a-parameter-appears-inside-a-min-expression-in-jump/133661 "2025-11-04T19:03:27Z")

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Hi everyone! I’m trying to extend a large (mixed-integer) linear model to handle Parameters, using the ParametricOptInterface.jl package. However, I’m running into an issue when a parameter is used inside a min() funct…

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## [Slow decrease of loss and an error during fitting an ODE to data](https://discourse.julialang.org/t/slow-decrease-of-loss-and-an-error-during-fitting-an-ode-to-data/126050)

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**Author:** [@Ashima\_Kalathingal](https://discourse.julialang.org/u/Ashima_Kalathingal)\
**Replies:** 4\
**Last updated:** [February 21, 2025, 6:14pm UTC](https://discourse.julialang.org/t/slow-decrease-of-loss-and-an-error-during-fitting-an-ode-to-data/126050 "2025-02-21T18:14:21Z")

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Hello, I have been trying to fit one parameter of a an ODE using the experimental data. I used the following example to write the code The problem is that the MSE loss is decreasing really really slowly even though …

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## [Elegant handling of possibly-state-dependent parameters in physical simulation](https://discourse.julialang.org/t/elegant-handling-of-possibly-state-dependent-parameters-in-physical-simulation/121640)

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**Author:** [@Ickaser](https://discourse.julialang.org/u/Ickaser)\
**Replies:** 1\
**Last updated:** [October 23, 2024, 1:34pm UTC](https://discourse.julialang.org/t/elegant-handling-of-possibly-state-dependent-parameters-in-physical-simulation/121640 "2024-10-23T13:34:44Z")

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For a couple years now, I have been using OrdinaryDiffEq for developing a handful of models for describing the process of pharmaceutical lyophilization. The more time I spend, the more I learn about more aspects of Julia…

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## [\[FR\] a new variant on method static parameter matching for getting the upper bound](https://discourse.julialang.org/t/fr-a-new-variant-on-method-static-parameter-matching-for-getting-the-upper-bound/118261)

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**Author:** [@nsajko](https://discourse.julialang.org/u/nsajko)\
**Replies:** 0\
**Last updated:** [August 16, 2024, 9:16am UTC](https://discourse.julialang.org/t/fr-a-new-variant-on-method-static-parameter-matching-for-getting-the-upper-bound/118261 "2024-08-16T09:16:48Z")

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The method static parameter matching we currently have works like so: unless the lower bound and the upper bound on the parameter are equal, the parameter is undefined. In practice, what we often actually want is just t…

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## [Using everything exported in a module and its submodules](https://discourse.julialang.org/t/using-everything-exported-in-a-module-and-its-submodules/117024)

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**Author:** [@K5Julien](https://discourse.julialang.org/u/K5Julien)\
**Replies:** 4\
**Last updated:** [July 14, 2024, 10:28am UTC](https://discourse.julialang.org/t/using-everything-exported-in-a-module-and-its-submodules/117024 "2024-07-14T10:28:12Z")

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I am currently replacing some String arguments of my mutable structure with dedicated types instead. The following MWE works perfectly fine: module MyPackage ### Some code module Options module SolveMod …

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## [Why are self-referential struct parameters impossible?](https://discourse.julialang.org/t/why-are-self-referential-struct-parameters-impossible/110982)

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**Author:** [@mnemnion](https://discourse.julialang.org/u/mnemnion)\
**Replies:** 19\
**Last updated:** [March 2, 2024, 11:46pm UTC](https://discourse.julialang.org/t/why-are-self-referential-struct-parameters-impossible/110982 "2024-03-02T23:46:18Z")

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Neither of these compiles: struct Tree{V\<:Any,T\<:Union{Tree,Nothing}} value::V left::T right::T end struct Tree{V,T} where {V\<:Any,T\<:Union{Tree,Nothing}} value::V left::T right::T end It m…

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## [Better way to name or inherit parameters with NonlinearSolve.jl?](https://discourse.julialang.org/t/better-way-to-name-or-inherit-parameters-with-nonlinearsolve-jl/110213)

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**Author:** [@Nathan\_Boyer](https://discourse.julialang.org/u/Nathan_Boyer)\
**Replies:** 3\
**Last updated:** [February 14, 2024, 7:08pm UTC](https://discourse.julialang.org/t/better-way-to-name-or-inherit-parameters-with-nonlinearsolve-jl/110213 "2024-02-14T19:08:05Z")

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I am using NonlinearSolve.jl for simple interval root finding. It is working well, but the way I am handling parameters is sticking out to me like a code smell. Is there a better way to pack and unpack the parameter ve…

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## [How to create a single shared parameter for multiple gates within a circuit directly using Yao.jl?](https://discourse.julialang.org/t/how-to-create-a-single-shared-parameter-for-multiple-gates-within-a-circuit-directly-using-yao-jl/104648)

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**Author:** [@nethaji8](https://discourse.julialang.org/u/nethaji8)\
**Replies:** 3\
**Last updated:** [October 7, 2023, 5:10am UTC](https://discourse.julialang.org/t/how-to-create-a-single-shared-parameter-for-multiple-gates-within-a-circuit-directly-using-yao-jl/104648 "2023-10-07T05:10:32Z")

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I am trying to parameterize a circuit using a single variable θ in the code below but the output is: Number of parameters in the circuit: 4 . Can someone please help me create a single shared parameter for multiple g…

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## [Inner and Outer constructors with Parameters.jl prevent incremental compilation?](https://discourse.julialang.org/t/inner-and-outer-constructors-with-parameters-jl-prevent-incremental-compilation/103061)

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**Author:** [@Iddingsite](https://discourse.julialang.org/u/Iddingsite)\
**Replies:** 2\
**Last updated:** [August 22, 2023, 4:21pm UTC](https://discourse.julialang.org/t/inner-and-outer-constructors-with-parameters-jl-prevent-incremental-compilation/103061 "2023-08-22T16:21:49Z")

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Hi all! I am trying to familiarise myself with outer and inner constructors and I would like to know if I am doing something wrong. I wrote a structure with 1 outer and 1 inner constructor, using also Parameters and Uni…

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## [Package-Compiler stops compile process because of arguments missing](https://discourse.julialang.org/t/package-compiler-stops-compile-process-because-of-arguments-missing/102472)

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**Author:** [@Miroslav-Stimac](https://discourse.julialang.org/u/Miroslav-Stimac)\
**Replies:** 0\
**Last updated:** [August 4, 2023, 7:51am UTC](https://discourse.julialang.org/t/package-compiler-stops-compile-process-because-of-arguments-missing/102472 "2023-08-04T07:51:16Z")

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Hello, I developed a program that requires a few arguments and when the program starts, it checks whether the correct arguments were given and if not, then it raises an exception. For example: # Read the arguments give…

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## [Error thrown when attempting Parameter Identifiability](https://discourse.julialang.org/t/error-thrown-when-attempting-parameter-identifiability/102440)

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**Author:** [@CurioMath](https://discourse.julialang.org/u/CurioMath)\
**Replies:** 2\
**Last updated:** [August 4, 2023, 5:29am UTC](https://discourse.julialang.org/t/error-thrown-when-attempting-parameter-identifiability/102440 "2023-08-04T05:29:06Z")

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Hi, I’m really excited to dig around the Parameter Identifiability in ODE Models, that I came across in ModelingToolkit.jl as well as in Overview of Julia’s SciML documentation. I have tried the same on my ODE model, bu…

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## [How can I see what parameters are making my code erroring when broadcasting a function call?](https://discourse.julialang.org/t/how-can-i-see-what-parameters-are-making-my-code-erroring-when-broadcasting-a-function-call/96130)

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**Author:** [@bertulli](https://discourse.julialang.org/u/bertulli)\
**Replies:** 3\
**Last updated:** [March 15, 2023, 8:59pm UTC](https://discourse.julialang.org/t/how-can-i-see-what-parameters-are-making-my-code-erroring-when-broadcasting-a-function-call/96130 "2023-03-15T20:59:04Z")

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Hi all! I have a function that raises a MethodError when broadcasted to a large vector of Strings. The error simply says julia\> df\_model\_measure\_master\[!, dest\_source\_eq\_sym\] = has\_dest\_source\_eq.(df\_model\_measure\_mast…

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## [Parameter estimation of an ODE in Julia is slower than in R](https://discourse.julialang.org/t/parameter-estimation-of-an-ode-in-julia-is-slower-than-in-r/85114)

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**Author:** [@laurar1891](https://discourse.julialang.org/u/laurar1891)\
**Replies:** 25\
**Last updated:** [August 7, 2022, 11:15pm UTC](https://discourse.julialang.org/t/parameter-estimation-of-an-ode-in-julia-is-slower-than-in-r/85114 "2022-08-07T23:15:04Z")

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I’ve been trying to estimate parameters (using max likelihood) of an ODE using the DifferentialEquations and Optim packages in Julia aiming to get a faster convergence compared to R. Problem is that I still can do it fas…

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## [Change construction type parameters for a type in a vector?](https://discourse.julialang.org/t/change-construction-type-parameters-for-a-type-in-a-vector/84441)

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**Author:** [@emmettgb](https://discourse.julialang.org/u/emmettgb)\
**Replies:** 14\
**Last updated:** [July 19, 2022, 5:52pm UTC](https://discourse.julialang.org/t/change-construction-type-parameters-for-a-type-in-a-vector/84441 "2022-07-19T17:52:17Z")

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I have an abstract type: abstract type Pickle end I have a sub-type mutable struct Dill \<: Pickle rating::Integer end If I construct a Vector{Dill}: \[Dill(5), Dill(6,)\] The type of this is Vector{Dill}. What I …

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## [How to make a function 120 times faster](https://discourse.julialang.org/t/how-to-make-a-function-120-times-faster/83848)

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**Author:** [@rocco\_sprmnt21](https://discourse.julialang.org/u/rocco_sprmnt21)\
**Replies:** 15\
**Last updated:** [July 7, 2022, 10:15am UTC](https://discourse.julialang.org/t/how-to-make-a-function-120-times-faster/83848 "2022-07-07T10:15:39Z")

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The function has the purpose of labeling the groups of “interconnected” cells \[two cells are connected if have a 1 and are side by side or one above the other\]. I had tried a first crude algorithm that did the job aroun…