# General Usage

**URL:** https://discourse.julialang.org/c/usage/6.md?page=13

[Latest](https://discourse.julialang.org/latest.md) · [Categories](https://discourse.julialang.org/categories.md) · [Tags](https://discourse.julialang.org/tags.md)

**Page:** 14

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## [Equivalent of numpy.tobytes and numpy.frombuffer in Julia](https://discourse.julialang.org/t/equivalent-of-numpy-tobytes-and-numpy-frombuffer-in-julia/136554)

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**Author:** [@lilachint](https://discourse.julialang.org/u/lilachint)\
**Replies:** 4\
**Last updated:** [April 4, 2026, 4:05pm UTC](https://discourse.julialang.org/t/equivalent-of-numpy-tobytes-and-numpy-frombuffer-in-julia/136554 "2026-04-04T16:05:48Z")

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Hi! As the topic stated, I once built a Python package that uses numpy.tobytes (source) and numpy.frombuffer (source) when caching things with SQLite. In Julia, I want to do this with BitArrays instead to save even more…

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## [Emit LaTeX document from Julia](https://discourse.julialang.org/t/emit-latex-document-from-julia/136273)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 12\
**Last updated:** [April 4, 2026, 1:53pm UTC](https://discourse.julialang.org/t/emit-latex-document-from-julia/136273 "2026-04-04T13:53:31Z")

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I am generating a lot of plots and tables (in Julia) for a research project, to be shared with coauthors. It used to be that I would dump the tables in a directory and tried to be good with file naming, but it got beyond…

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## [Some update broke our project - how to fix faster](https://discourse.julialang.org/t/some-update-broke-our-project-how-to-fix-faster/136551)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 1\
**Last updated:** [April 4, 2026, 10:46am UTC](https://discourse.julialang.org/t/some-update-broke-our-project-how-to-fix-faster/136551 "2026-04-04T10:46:12Z")

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Some update of the sciml packages broke our project, see: Now I want to change \`Project.toml to make it work again, but this is very time-consuming, because after the first package that fails to pre-compile, it continu…

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## [Contradictory nested function performance and allocation](https://discourse.julialang.org/t/contradictory-nested-function-performance-and-allocation/136548)

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**Author:** [@lilachint](https://discourse.julialang.org/u/lilachint)\
**Replies:** 2\
**Last updated:** [April 4, 2026, 8:38am UTC](https://discourse.julialang.org/t/contradictory-nested-function-performance-and-allocation/136548 "2026-04-04T08:38:44Z")

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Recently when working on sorting data with Hilbert curves, I noticed something very peculiar when benchmarking. function hilbert\_sort(m::AbstractMatrix{\<:Integer}, b::Integer; rev::Bool = false) return m\[:, hilbert\_…

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## ["Dual" ticks on colourbar](https://discourse.julialang.org/t/dual-ticks-on-colourbar/136540)

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**Author:** [@dolefeast](https://discourse.julialang.org/u/dolefeast)\
**Replies:** 0\
**Last updated:** [April 3, 2026, 10:42am UTC](https://discourse.julialang.org/t/dual-ticks-on-colourbar/136540 "2026-04-03T10:42:28Z")

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I have two functions f, g with different ranges but same domain. I visualize function f through a heatmap and function g through a contour map. To be able to plot them together I have to rescale g as seen in the code bel…

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## [Multithreading performance in different Julia versions](https://discourse.julialang.org/t/multithreading-performance-in-different-julia-versions/136538)

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**Author:** [@songjhaha](https://discourse.julialang.org/u/songjhaha)\
**Replies:** 0\
**Last updated:** [April 3, 2026, 8:05am UTC](https://discourse.julialang.org/t/multithreading-performance-in-different-julia-versions/136538 "2026-04-03T08:05:40Z")

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I found an example performances quite diff in Julia 1.10 vs other version in MWE: # GC.enable\_logging(true) function myinterp1(X, V, Xq, method) complex.( \_myinterp1(X, real(V), Xq, method), \_myinterp1(X, imag(…

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## [Cannot install OrdinaryDiffEq in Julia 1.10.11](https://discourse.julialang.org/t/cannot-install-ordinarydiffeq-in-julia-1-10-11/136518)

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**Author:** [@dmitry-kabanov](https://discourse.julialang.org/u/dmitry-kabanov)\
**Replies:** 16\
**Last updated:** [April 2, 2026, 4:50pm UTC](https://discourse.julialang.org/t/cannot-install-ordinarydiffeq-in-julia-1-10-11/136518 "2026-04-02T16:50:06Z")

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Hi, I was trying to install a new Julia (well, old) version to find a bug. So, I have used juliaup add 1.10 which results in the installation of the version 1.10.11. I have started that version with julia +1.10 --projec…

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## [Renaming an existing package with changed capitalization](https://discourse.julialang.org/t/renaming-an-existing-package-with-changed-capitalization/136511)

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**Author:** [@becker0210](https://discourse.julialang.org/u/becker0210)\
**Replies:** 2\
**Last updated:** [April 1, 2026, 6:22pm UTC](https://discourse.julialang.org/t/renaming-an-existing-package-with-changed-capitalization/136511 "2026-04-01T18:22:07Z")

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Our organization is considering rebranding our software tool suite (several application interfaces and code-bases) which has been around for a long time (15+ years) and the name and capitalization is reflected in the cur…

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## [Filtering stack trace](https://discourse.julialang.org/t/filtering-stack-trace/136489)

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**Author:** [@Lincoln\_Hannah](https://discourse.julialang.org/u/Lincoln_Hannah)\
**Replies:** 2\
**Last updated:** [April 1, 2026, 5:38pm UTC](https://discourse.julialang.org/t/filtering-stack-trace/136489 "2026-04-01T17:38:14Z")

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Can I set a filter so the error message stack trace only shows lines from my .jl files? Not base Julia or downloaded packages. Or could you add a link at the top of the error message to the line in the stack trace that…

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## [Unable to add an issue in LinearSolve.jl](https://discourse.julialang.org/t/unable-to-add-an-issue-in-linearsolve-jl/136508)

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**Author:** [@John\_Washbourne](https://discourse.julialang.org/u/John_Washbourne)\
**Replies:** 2\
**Last updated:** [April 1, 2026, 5:14pm UTC](https://discourse.julialang.org/t/unable-to-add-an-issue-in-linearsolve-jl/136508 "2026-04-01T17:14:23Z")

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I am unable to add an issue or question at GitHub - SciML/LinearSolve.jl: LinearSolve.jl: High-Performance Unified Interface for Linear Solvers in Julia. Easily switch between factorization and Krylov methods, add precon…

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## [CI Failing due to not having a package installed](https://discourse.julialang.org/t/ci-failing-due-to-not-having-a-package-installed/136463)

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**Author:** [@Mitch\_Phillipson](https://discourse.julialang.org/u/Mitch_Phillipson)\
**Replies:** 4\
**Last updated:** [April 1, 2026, 10:47am UTC](https://discourse.julialang.org/t/ci-failing-due-to-not-having-a-package-installed/136463 "2026-04-01T10:47:23Z")

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Hello, I have a package running a suite of tests on a few different Julia versions and OSs. I am getting a strange error on Julia-nightly - Windows-latest: ERROR: LoadError: ArgumentError: Package DataFrames \[a93c6f00-…

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## [Enzyme/Reactant: second-order AD (Laplacian) not working with Lux on GPU](https://discourse.julialang.org/t/enzyme-reactant-second-order-ad-laplacian-not-working-with-lux-on-gpu/136444)

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**Author:** [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)\
**Replies:** 5\
**Last updated:** [April 1, 2026, 6:39am UTC](https://discourse.julialang.org/t/enzyme-reactant-second-order-ad-laplacian-not-working-with-lux-on-gpu/136444 "2026-04-01T06:39:23Z")

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Hi all, I’m implementing VMC (Variational Monte Carlo) for quantum many-body systems in the continuum, where I need to compute the Laplacian ∇²logψ/ψ of a neural network wavefunction. I’m trying to use Lux + Reactant +…

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## [Associativity / Commutativity for Boolean operations in SymbolicUtils.jl](https://discourse.julialang.org/t/associativity-commutativity-for-boolean-operations-in-symbolicutils-jl/136468)

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**Author:** [@logic](https://discourse.julialang.org/u/logic)\
**Replies:** 5\
**Last updated:** [March 31, 2026, 5:11pm UTC](https://discourse.julialang.org/t/associativity-commutativity-for-boolean-operations-in-symbolicutils-jl/136468 "2026-03-31T17:11:58Z")

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I’m working on a Boolean Algebra Rewriter with SymbolicUtils.jl, and I’ve noticed that for some reason, associativity and commutativity are not being properly applied for Boolean operations, which makes defining rules pa…

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## [How to debug a silent crash?](https://discourse.julialang.org/t/how-to-debug-a-silent-crash/136383)

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**Author:** [@AwesomeQuest](https://discourse.julialang.org/u/AwesomeQuest)\
**Replies:** 8\
**Last updated:** [March 31, 2026, 3:35pm UTC](https://discourse.julialang.org/t/how-to-debug-a-silent-crash/136383 "2026-03-31T15:35:07Z")

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I’m writing a script which calls a C library and the program is just stopping prematurely with no output. How do I debug this? A little context: I’m passing a Julia function as a callback to the SimpleBLE C library th…

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## [Equivalent of numpy.gradient in Julia](https://discourse.julialang.org/t/equivalent-of-numpy-gradient-in-julia/93172)

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**Author:** [@fdekerme](https://discourse.julialang.org/u/fdekerme)\
**Replies:** 24\
**Last updated:** [March 31, 2026, 10:52am UTC](https://discourse.julialang.org/t/equivalent-of-numpy-gradient-in-julia/93172 "2026-03-31T10:52:42Z")

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Hello, :grin: I need to calculate the gradient of a 3 dimensional matrix. Is there today in 2023 an equivalent of numpy.gradient in Julia?(numpy.gradient — NumPy v1.24 Manual) This question had already been asked, but …

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## [Problem trying to install jetls](https://discourse.julialang.org/t/problem-trying-to-install-jetls/136453)

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**Author:** [@brianguenter](https://discourse.julialang.org/u/brianguenter)\
**Replies:** 3\
**Last updated:** [March 29, 2026, 10:01pm UTC](https://discourse.julialang.org/t/problem-trying-to-install-jetls/136453 "2026-03-29T22:01:04Z")

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I’m getting this error when trying to install the jetls language server (@v1.12) pkg\> add https://github.com/aviatesk/JETLS.jl#release Updating git-repo \`https://github.com/aviatesk/JETLS.jl\` Resolving package ve…

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## [Idiomatic way to avoid the closure capture bug?](https://discourse.julialang.org/t/idiomatic-way-to-avoid-the-closure-capture-bug/136435)

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**Author:** [@araujoms](https://discourse.julialang.org/u/araujoms)\
**Replies:** 13\
**Last updated:** [March 29, 2026, 3:32pm UTC](https://discourse.julialang.org/t/idiomatic-way-to-avoid-the-closure-capture-bug/136435 "2026-03-29T15:32:53Z")

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I’ve been looking for ways to generate tuples without falling prey to the infamous closure capture bug. I’ve found essentially four different ways, and wanted to know if it makes a difference which one I use, or whether …

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## [DAG sorting and op rewriting for IR-level structural diffing — anyone worked on this?](https://discourse.julialang.org/t/dag-sorting-and-op-rewriting-for-ir-level-structural-diffing-anyone-worked-on-this/136419)

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**Author:** [@obsidianjulua](https://discourse.julialang.org/u/obsidianjulua)\
**Replies:** 1\
**Last updated:** [March 27, 2026, 10:29pm UTC](https://discourse.julialang.org/t/dag-sorting-and-op-rewriting-for-ir-level-structural-diffing-anyone-worked-on-this/136419 "2026-03-27T22:29:51Z")

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I’m working on a compiler infrastructure project (RepliBuild.jl) that needs to diff two DAGs — one representing Julia IR and one representing C++ IR derived from DWARF metadata — and identify structural mismatches by byt…

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## [CondaPkg installs incompatible free-threaded NumPy](https://discourse.julialang.org/t/condapkg-installs-incompatible-free-threaded-numpy/136421)

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**Author:** [@Benny](https://discourse.julialang.org/u/Benny)\
**Replies:** 13\
**Last updated:** [March 27, 2026, 10:13pm UTC](https://discourse.julialang.org/t/condapkg-installs-incompatible-free-threaded-numpy/136421 "2026-03-27T22:13:53Z")

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I’ve been working on a small Python project recently, and I’m now considering using PythonCall again to speed up a few places more easily. But when I went to make a fresh Julia environment with current versions, I hit a …

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## [About Pkg Apps and Extentions](https://discourse.julialang.org/t/about-pkg-apps-and-extentions/136418)

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**Author:** [@BambOoxX](https://discourse.julialang.org/u/BambOoxX)\
**Replies:** 8\
**Last updated:** [March 27, 2026, 9:14pm UTC](https://discourse.julialang.org/t/about-pkg-apps-and-extentions/136418 "2026-03-27T21:14:22Z")

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While reading 6. Apps · Pkg.jl, I was wondering if one could define a app (with its own submodule) inside of a package or if it needed to be another package altogether. In particular, what I would ideally like to do is …

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## [Strange error when using the FBDF solver](https://discourse.julialang.org/t/strange-error-when-using-the-fbdf-solver/136405)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 1\
**Last updated:** [March 27, 2026, 12:58pm UTC](https://discourse.julialang.org/t/strange-error-when-using-the-fbdf-solver/136405 "2026-03-27T12:58:54Z")

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When I run the following script Tethers.jl/src/Tether\_06c.jl at main · ufechner7/Tethers.jl · GitHub on Windows with continues callbacks using the FBDF solver I get the following error: 4 ┌ Warning: \`ODESystem(args...; …

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## [Reactant.jl + Enzyme: ~10 min compilation overhead triggered by hidden-to-hidden Dense layers](https://discourse.julialang.org/t/reactant-jl-enzyme-10-min-compilation-overhead-triggered-by-hidden-to-hidden-dense-layers/136374)

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**Author:** [@Yuan-Ru-Lin](https://discourse.julialang.org/u/Yuan-Ru-Lin)\
**Replies:** 1\
**Last updated:** [March 27, 2026, 11:22am UTC](https://discourse.julialang.org/t/reactant-jl-enzyme-10-min-compilation-overhead-triggered-by-hidden-to-hidden-dense-layers/136374 "2026-03-27T11:22:11Z")

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I’ve been investigating compilation times with Reactant.jl + Lux + AutoEnzyme() on an NVIDIA GPU and found a reproducible jump in TTFT (Time-To-First-Training) when a model includes hidden-to-hidden Dense layers. Minima…

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## [Functions with identical native code but different benchmarks](https://discourse.julialang.org/t/functions-with-identical-native-code-but-different-benchmarks/136336)

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**Author:** [@matthias314](https://discourse.julialang.org/u/matthias314)\
**Replies:** 14\
**Last updated:** [March 27, 2026, 4:27am UTC](https://discourse.julialang.org/t/functions-with-identical-native-code-but-different-benchmarks/136336 "2026-03-27T04:27:13Z")

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I’m currently rewriting some low-level code in one of my packages. I’m seeing that the new function runs 2-3 times slower than the old one (~12ns instead of ~5ns) although @code\_native shows exactly the same code. The sl…

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## [Installing IJulia for all users for JupyterHub](https://discourse.julialang.org/t/installing-ijulia-for-all-users-for-jupyterhub/42528)

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**Author:** [@camtheman256](https://discourse.julialang.org/u/camtheman256)\
**Replies:** 7\
**Last updated:** [March 26, 2026, 12:32pm UTC](https://discourse.julialang.org/t/installing-ijulia-for-all-users-for-jupyterhub/42528 "2026-03-26T12:32:17Z")

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Hi, I’m trying to figure out how to setup IJulia for all users on my JupyterHub server. I know that Julia has “depots” in global locations, but I’m not sure how to install packages there. When I run Pkg.depots(), I see …

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## [Testing with GLMakie](https://discourse.julialang.org/t/testing-with-glmakie/136404)

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**Author:** [@ohmsweetohm1](https://discourse.julialang.org/u/ohmsweetohm1)\
**Replies:** 1\
**Last updated:** [March 26, 2026, 10:45am UTC](https://discourse.julialang.org/t/testing-with-glmakie/136404 "2026-03-26T10:45:07Z")

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I have a package that produces a plot for a type. The package also has a GLMakie extension, but when I run the CI tests I get this: ┌ Warning: OpenGL/GLFW wasn't loaded correctly or couldn't be initialized. │ Th…

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## [How to display dynamic value for each agent in interactive plot](https://discourse.julialang.org/t/how-to-display-dynamic-value-for-each-agent-in-interactive-plot/136361)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 5\
**Last updated:** [March 25, 2026, 9:15am UTC](https://discourse.julialang.org/t/how-to-display-dynamic-value-for-each-agent-in-interactive-plot/136361 "2026-03-25T09:15:15Z")

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Hello, I am using Agents.jl and I would like to plot a value for each agent dynamically with abmplot with enable\_inspection = true. This example shows how to generate a static plot of this variety (here is the plot). …

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## [Complex workaround needed. Why?](https://discourse.julialang.org/t/complex-workaround-needed-why/136371)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 3\
**Last updated:** [March 25, 2026, 7:31am UTC](https://discourse.julialang.org/t/complex-workaround-needed-why/136371 "2026-03-25T07:31:35Z")

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I need this workaround to avoid crashes due to version conflicts od shared libraries on Linux: if \[\[ "$(uname -s)" == "Linux" \]\]; then export FONTCONFIG\_FILE=/etc/fonts/fonts.conf # On Ubuntu 22.04 the system ha…

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## [Generating structs from JSON files](https://discourse.julialang.org/t/generating-structs-from-json-files/136360)

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**Author:** [@langestefan](https://discourse.julialang.org/u/langestefan)\
**Replies:** 1\
**Last updated:** [March 24, 2026, 11:44pm UTC](https://discourse.julialang.org/t/generating-structs-from-json-files/136360 "2026-03-24T23:44:14Z")

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I need to generate structs (and enums) from a set of JSON files. It seems that only JSON3.jl currently supports this feature? The migration guide does state: If you rely heavily on this feature, continue using JSON3.j…

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## [Building a UI for a SciML biological model: Genie.jl (Web App) vs. Makie.jl (Local GUI)?](https://discourse.julialang.org/t/building-a-ui-for-a-sciml-biological-model-genie-jl-web-app-vs-makie-jl-local-gui/136344)

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**Author:** [@Luca\_Maria\_Moccia](https://discourse.julialang.org/u/Luca_Maria_Moccia)\
**Replies:** 17\
**Last updated:** [March 24, 2026, 1:38pm UTC](https://discourse.julialang.org/t/building-a-ui-for-a-sciml-biological-model-genie-jl-web-app-vs-makie-jl-local-gui/136344 "2026-03-24T13:38:56Z")

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Hi everyone, My colleague and I are currently doing our Master’s internship, and we are working on a synaptic plasticity model built with the SciML ecosystem. Our main goal right now is to build a user-friendly interfa…

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## [Styling inline results in VSCode](https://discourse.julialang.org/t/styling-inline-results-in-vscode/136358)

<div class="topic-metadata">

**Author:** [@owiecc](https://discourse.julialang.org/u/owiecc)\
**Replies:** 1\
**Last updated:** [March 24, 2026, 1:07pm UTC](https://discourse.julialang.org/t/styling-inline-results-in-vscode/136358 "2026-03-24T13:07:54Z")

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Is it possible to apply a custom style to the inline results? I am using a Nord theme and the results are a bit too visible to me. I like to have them but they do also create visual noise. I know I can clear with a short…

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