# Passing simulation parameters into app

**URL:** <https://discourse.julialang.org/t/passing-simulation-parameters-into-app/117438>\
**Category:** General Usage\
**Tags:** question\
**Created:** [July 24, 2024, 7:28pm UTC](https://discourse.julialang.org/t/passing-simulation-parameters-into-app/117438 "2024-07-24T19:28:40Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![eldee](https://avatars.discourse-cdn.com/v4/letter/e/b5a626/32.png) [@eldee](https://discourse.julialang.org/u/eldee)\
**Post date:** [July 26, 2024, 9:50am UTC](https://discourse.julialang.org/t/passing-simulation-parameters-into-app/117438/2 "2024-07-26T09:50:02Z")

</div>

Your code using `include` already works for me, if I correct the brackets in `invokelatest` to `Base.invokelatest(p.b[1], 3)` and remove the `string_to_funct` line. To create an app, you should of course also move the “inputs.jl” argument into `ARGS`.

> **Full program**
>
> > **Folder structure**
> >
> > ```julia
> > Tester
> > │ Manifest.toml
> > │ precompile_app.jl
> > │ Project.toml
> > │
> > ├───compiled
> > │ ├───bin
> > │ │ julia.exe
> > │ │ ...
> > │ │ Tester.exe
> > │ │
> > │ └───share
> > │ └───julia
> > │ cert.pem
> > │ LocalPreferences.toml
> > │ Project.toml
> > │
> > ├───inputs
> > │ inputs.jl
> > │ inputs2.jl
> > │
> > └───src
> > Tester.jl
> > 
> > ```
> 
> Most of these files are created by Pkg
> 
> ```julia
> using Pkg
> Pkg.generate("Tester")
> 
> ```
> 
> and `PackageCompiler` (see below).
> 
> Manually added files are `Tester.jl`, which corresponds to your `main.jl`,
> 
> > **Tester.jl**
> >
> > ```julia
> > module Tester
> > 
> > # Load parameters from file and call solver
> > module Tester
> > 
> > # Load parameters from file and call solver
> > function julia_main()::Cint
> > include(ARGS[1]) # Loads in p
> > 	
> > # Run solver with input parameters
> > solver(p)
> > return 0
> > end
> > 
> > function solver(p)
> > println("Running solver with p = ",p)
> > println("a = ",p.a) # 1 for inputs1.jl, 3 for inputs2.jl
> > println("p.b[1] = ", p.b[1])
> > println("b[1](3) = ", Base.invokelatest(p.b[1], 3)) # 3^2 = 9 for inputs1.jl, 3^3 = 27 for inputs2.jl
> > end
> > 
> > end
> > 
> > ```
> 
> the input files
> 
> > **inputs1.jl**
> >
> > ```julia
> > p = (
> > a = 1,
> > b = [(t) -> t^2]
> > )
> > 
> > ```
> > 
> > which is your `inputs.jl`
> 
> > **inputs2.jl**
> >
> > ```julia
> > p = (
> > a = 3,
> > b = [(t) -> t^3]
> > )
> > 
> > ```
> 
> and the optional precompilation script `precompile_app.jl`, which is not really useful for this small example, but could be for your full program.
> 
> > **precompile\_app.jl**
> >
> > ```julia
> > using Tester
> > 
> > push!(ARGS, "./inputs/inputs1.jl")
> > Tester.julia_main()
> > 
> > ```
> > 
> > (cf. [PackageCompiler.jl/examples/MyApp/precompile\_app.jl at master · JuliaLang/PackageCompiler.jl · GitHub](https://github.com/JuliaLang/PackageCompiler.jl/blob/master/examples/MyApp/precompile_app.jl) and [PackageCompiler.jl how to specify ARGS for create\_app? - #2 by jsjie](https://discourse.julialang.org/t/packagecompiler-jl-how-to-specify-args-for-create-app/117405/2))
> 
> To compile, I opened Julia in the parent directory of Tester, and used
> 
> ```julia
> ]activate Tester
> using PackageCompiler
> create_app("Tester", "Tester/compiled")  
> # or: create_app("Tester", "Tester/compiled", precompile_execution_file="Tester/precompile_app.jl")
> 
> ```
> 
> (assuming ./Tester/compiled does not already exist). As output I get
> 
> ```julia
> > .\Tester\compiled\bin\Tester.exe .\Tester\inputs\inputs1.jl
> Running solver with p = (a = 1, b = [Tester.var"#1#2"()])
> a = 1
> p.b[1] = #1
> b[1](3) = 9
> > .\Tester\compiled\bin\Tester.exe .\Tester\inputs\inputs2.jl
> Running solver with p = (a = 3, b = [Tester.var"#1#2"()])
> a = 3
> p.b[1] = #1
> b[1](3) = 27
> 
> ```
> 
> You will notice that this is on Windows. If relevant, here’s my full `versioninfo()`:
> 
> > **versioninfo**
> >
> > ```julia
> > Julia Version 1.10.4
> > Commit 48d4fd4843 (2024-06-04 10:41 UTC)
> > Build Info:
> > Official https://julialang.org/ release
> > Platform Info:
> > OS: Windows (x86_64-w64-mingw32)
> > CPU: 8 × Intel(R) Core(TM) i7-7700K CPU @ 4.20GHz
> > WORD_SIZE: 64
> > LIBM: libopenlibm
> > LLVM: libLLVM-15.0.7 (ORCJIT, skylake)
> > Threads: 8 default, 0 interactive, 4 GC (on 8 virtual cores)
> > Environment:
> > JULIA_NUM_THREADS = auto
> > 
> > ```
> 
> and I am using PackageCompiler v2.1.17.

I kind of like the `include` approach you suggest, due to the amount of freedom it brings (you can just ‘import’ any object produced by Julia code), but I cannot say if there are any downsides, or what the idiomatic approach would be.

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