# General Usage

**URL:** https://discourse.julialang.org/c/usage/6.md?page=55

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**Page:** 56

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## [Error occurs while adding packages due to dependency failed to precompile](https://discourse.julialang.org/t/error-occurs-while-adding-packages-due-to-dependency-failed-to-precompile/130243)

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**Author:** [@ddn](https://discourse.julialang.org/u/ddn)\
**Replies:** 1\
**Last updated:** [June 26, 2025, 8:37pm UTC](https://discourse.julialang.org/t/error-occurs-while-adding-packages-due-to-dependency-failed-to-precompile/130243 "2025-06-26T20:37:07Z")

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Hi there, Ive been using a package on Julia for a while and it worked fine, until today when I tried to update it, there seems to be an error about precompilation. I’m not sure how to solve it so I deleted Julia and rein…

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## [Barrier to synchronize threads](https://discourse.julialang.org/t/barrier-to-synchronize-threads/130235)

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**Author:** [@dubosipsl](https://discourse.julialang.org/u/dubosipsl)\
**Replies:** 3\
**Last updated:** [June 26, 2025, 8:37pm UTC](https://discourse.julialang.org/t/barrier-to-synchronize-threads/130235 "2025-06-26T20:37:25Z")

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Hello all, AFAIK there is now built-in way to synchronize Julia threads at a barrier (think OpenMP Barrier). The expected functionality is as follows: function test\_barrier(nt, ns) @sync begin b = Barrier(…

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## [Fitting copula with known marginal, Copulas.jl](https://discourse.julialang.org/t/fitting-copula-with-known-marginal-copulas-jl/130255)

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**Author:** [@rand5](https://discourse.julialang.org/u/rand5)\
**Replies:** 1\
**Last updated:** [June 26, 2025, 8:19pm UTC](https://discourse.julialang.org/t/fitting-copula-with-known-marginal-copulas-jl/130255 "2025-06-26T20:19:44Z")

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An example of fitting a copula using the Copulas.jl package is given as the following in the docs: MyCop = SurvivalCopula{4,ClaytonCopula,(2,4)} MyMargs = Tuple{LogNormal,Pareto,Gamma,Normal} MyD = SklarDist{MyCop, MyMa…

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## [Building environments without any artifacts involved](https://discourse.julialang.org/t/building-environments-without-any-artifacts-involved/130251)

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**Author:** [@Herve](https://discourse.julialang.org/u/Herve)\
**Replies:** 1\
**Last updated:** [June 26, 2025, 7:54pm UTC](https://discourse.julialang.org/t/building-environments-without-any-artifacts-involved/130251 "2025-06-26T19:54:30Z")

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Hi. I am wondering if there exists a tool to determine if a given package is installable without pulling any artifact. It has a meaning in different contexts: if I want to be able to review all code involved in my comp…

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## [Security Advisory: HTTP.jl, URIs.jl, Registrator.jl, GitForge.jl, and GitHub.jl](https://discourse.julialang.org/t/security-advisory-http-jl-uris-jl-registrator-jl-gitforge-jl-and-github-jl/130189)

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**Author:** [@avik](https://discourse.julialang.org/u/avik)\
**Replies:** 2\
**Last updated:** [June 26, 2025, 7:49pm UTC](https://discourse.julialang.org/t/security-advisory-http-jl-uris-jl-registrator-jl-gitforge-jl-and-github-jl/130189 "2025-06-26T19:49:42Z")

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Security vulnerabilities have been reported in a few Julia packages. We recommend all users upgrade to the latest version of these packages as soon as possible. Each vulnerability has been assigned a CVE and published as…

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## [How to Wrap Fortran Types with Opaque Pointers](https://discourse.julialang.org/t/how-to-wrap-fortran-types-with-opaque-pointers/130252)

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**Author:** [@ejmeitz](https://discourse.julialang.org/u/ejmeitz)\
**Replies:** 0\
**Last updated:** [June 26, 2025, 6:55pm UTC](https://discourse.julialang.org/t/how-to-wrap-fortran-types-with-opaque-pointers/130252 "2025-06-26T18:55:40Z")

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I am trying to create a wrapper for a rather large Fortran library. Many of the classes in this library have over a dozen fields and those fields are often their own classes. To avoid having to create a wrapper for all o…

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## [CUDA.jl on Jupyter / ubuntu 24](https://discourse.julialang.org/t/cuda-jl-on-jupyter-ubuntu-24/130246)

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**Author:** [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)\
**Replies:** 0\
**Last updated:** [June 26, 2025, 5:02pm UTC](https://discourse.julialang.org/t/cuda-jl-on-jupyter-ubuntu-24/130246 "2025-06-26T17:02:25Z")

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Hi, I’m running the latest julia + CUDA (I update regularly) on two ubuntu 24.04.2 different machines. I use to develop my codes in jupyter (also latest) and in recent weeks I’m experimenting random crashes when doing C…

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## [(VSCode//Julia language) ERROR: LoadError: TOML Parser error:](https://discourse.julialang.org/t/vscode-julia-language-error-loaderror-toml-parser-error/130245)

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**Author:** [@anafunguetto](https://discourse.julialang.org/u/anafunguetto)\
**Replies:** 0\
**Last updated:** [June 26, 2025, 4:51pm UTC](https://discourse.julialang.org/t/vscode-julia-language-error-loaderror-toml-parser-error/130245 "2025-06-26T16:51:04Z")

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I need help troubleshooting an error in VSCode. I’m working with Pumas AI using the Julia language in VSCode. When I start \>Start REPL I get the following error: ERROR: LoadError: TOML Parser error: �������������������…

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## [Weirdness of \`Type{Union{A,B}} where {B\<:SuperB}\`](https://discourse.julialang.org/t/weirdness-of-type-union-a-b-where-b-superb/130234)

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**Author:** [@MilesCranmer](https://discourse.julialang.org/u/MilesCranmer)\
**Replies:** 8\
**Last updated:** [June 26, 2025, 4:20pm UTC](https://discourse.julialang.org/t/weirdness-of-type-union-a-b-where-b-superb/130234 "2025-06-26T16:20:27Z")

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I think my mental model of Type{Union{A,B}} is incorrect because I truly do not understand the following behavior: julia\> struct Foo end julia\> Foo isa (Type{Union{Foo,T}} where {T\<:Base.IEEEFloat}) true julia\> Float3…

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## [Table with non-Symbol column names](https://discourse.julialang.org/t/table-with-non-symbol-column-names/130220)

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**Author:** [@jar1](https://discourse.julialang.org/u/jar1)\
**Replies:** 1\
**Last updated:** [June 26, 2025, 3:12pm UTC](https://discourse.julialang.org/t/table-with-non-symbol-column-names/130220 "2025-06-26T15:12:24Z")

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I would like a column-table like StructArray but with non-Symbol column names, such as for numbers, dates, etc. Does this exist? Is there a good reason it shouldn’t?

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## [How to resolve "Error: Could not parse entry for \`deps\`" for an old 1.5 Julia project](https://discourse.julialang.org/t/how-to-resolve-error-could-not-parse-entry-for-deps-for-an-old-1-5-julia-project/130237)

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**Author:** [@Datseris](https://discourse.julialang.org/u/Datseris)\
**Replies:** 2\
**Last updated:** [June 26, 2025, 2:53pm UTC](https://discourse.julialang.org/t/how-to-resolve-error-could-not-parse-entry-for-deps-for-an-old-1-5-julia-project/130237 "2025-06-26T14:53:34Z")

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Hello, about 3-4 years ago we published a textbook that utilized Julia and had code snippets integrated into the book pages. In addition, we associated with this textbook a GitHub repository in which we provide all the …

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## [Issues with librsvg-2-2.dll on Windows 11](https://discourse.julialang.org/t/issues-with-librsvg-2-2-dll-on-windows-11/130201)

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**Author:** [@rode](https://discourse.julialang.org/u/rode)\
**Replies:** 13\
**Last updated:** [June 26, 2025, 1:15pm UTC](https://discourse.julialang.org/t/issues-with-librsvg-2-2-dll-on-windows-11/130201 "2025-06-26T13:15:03Z")

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All of my packages dependent on librsvg-2-2.dll have suddenly stop working. I can confirm there is a file present in “bin”. I get a library could not load error. All packages were working until I did an update in package…

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## [Installed Julia 1.11 and error comes](https://discourse.julialang.org/t/installed-julia-1-11-and-error-comes/130209)

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**Author:** [@stefaniecg](https://discourse.julialang.org/u/stefaniecg)\
**Replies:** 6\
**Last updated:** [June 26, 2025, 11:16am UTC](https://discourse.julialang.org/t/installed-julia-1-11-and-error-comes/130209 "2025-06-26T11:16:06Z")

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I just installed Julia 1.11 and when i try to open the app, it fails as follows. I’m using MacOS Sequoia 15.5. Is this known?

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## [REPL in 1.11 freezes while typing on array indexing and field access](https://discourse.julialang.org/t/repl-in-1-11-freezes-while-typing-on-array-indexing-and-field-access/130204)

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**Author:** [@tamasgal](https://discourse.julialang.org/u/tamasgal)\
**Replies:** 4\
**Last updated:** [June 26, 2025, 6:53am UTC](https://discourse.julialang.org/t/repl-in-1-11-freezes-while-typing-on-array-indexing-and-field-access/130204 "2025-06-26T06:53:30Z")

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I have a very weird issue in the REPL with one of my packages. Unfortunately it’s very hard to boil it down to an MWE but I can already provide something which people can easily reproduce. You’ll need to add our public …

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## [Can not open this MAT file](https://discourse.julialang.org/t/can-not-open-this-mat-file/130215)

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**Author:** [@leon](https://discourse.julialang.org/u/leon)\
**Replies:** 6\
**Last updated:** [June 26, 2025, 1:14am UTC](https://discourse.julialang.org/t/can-not-open-this-mat-file/130215 "2025-06-26T01:14:33Z")

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I have two MAT files. I can open A but can not open B. When I used the command “@show(File)”. I got the below for A: F1 = MAT.MAT\_HDF5.MatlabHDF5File(HDF5.File: (read-only) /Volumes/A.mat, true, false, 1108, false) bu…

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## [Questions about Juliac](https://discourse.julialang.org/t/questions-about-juliac/130213)

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**Author:** [@Max\_Pan](https://discourse.julialang.org/u/Max_Pan)\
**Replies:** 1\
**Last updated:** [June 26, 2025, 1:41am UTC](https://discourse.julialang.org/t/questions-about-juliac/130213 "2025-06-26T01:41:11Z")

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At the moment, I am trying to use julia for a real-time system. As of so far, I have done a bunch of benchmarking for julia. So the script below attempts to measure the initial time to run matrix multiplication for two …

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## [What is the current status of GPU support in Julia?](https://discourse.julialang.org/t/what-is-the-current-status-of-gpu-support-in-julia/129613)

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**Author:** [@jsjie](https://discourse.julialang.org/u/jsjie)\
**Replies:** 19\
**Last updated:** [June 25, 2025, 11:32pm UTC](https://discourse.julialang.org/t/what-is-the-current-status-of-gpu-support-in-julia/129613 "2025-06-25T23:32:13Z")

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According to the official website, only NVIDIA GPUs using CUDA on Linux is offered tier 1 support. AMD GPUs using ROCm is only offered tier 3 support. However, the AMDGPU.jl repository does not have any warnings in the d…

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## [Finding \`Expr\`s with docstrings](https://discourse.julialang.org/t/finding-expr-s-with-docstrings/130214)

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**Author:** [@moble](https://discourse.julialang.org/u/moble)\
**Replies:** 3\
**Last updated:** [June 25, 2025, 9:30pm UTC](https://discourse.julialang.org/t/finding-expr-s-with-docstrings/130214 "2025-06-25T21:30:49Z")

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How do I detect when an Expr has a docstring? For example, if expr = quote """Here's a docstring!""" const a=1 end I can look at the result to see that it is translated into a macrocall of @doc (after skipping…

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## [Iterative 2D Convolution Optimization, Help?](https://discourse.julialang.org/t/iterative-2d-convolution-optimization-help/130200)

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**Author:** [@GA-Brady](https://discourse.julialang.org/u/GA-Brady)\
**Replies:** 1\
**Last updated:** [June 25, 2025, 8:54pm UTC](https://discourse.julialang.org/t/iterative-2d-convolution-optimization-help/130200 "2025-06-25T20:54:35Z")

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I need to write an iterative 2D convolution, i.e. Starting with a 4k sample image, run a convolution algorithm, then run the same convolution on the result. Padding is added to the image such that the result is 4K. My t…

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## [Julia SLURM + BLAS + Multithreading, threads not mapping well leading to poor performance](https://discourse.julialang.org/t/julia-slurm-blas-multithreading-threads-not-mapping-well-leading-to-poor-performance/130188)

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**Author:** [@jacksonjhayes](https://discourse.julialang.org/u/jacksonjhayes)\
**Replies:** 5\
**Last updated:** [June 25, 2025, 5:04pm UTC](https://discourse.julialang.org/t/julia-slurm-blas-multithreading-threads-not-mapping-well-leading-to-poor-performance/130188 "2025-06-25T17:04:36Z")

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I am running benchmarking of a code that uses: multithreading BLAS (multithreaded) BLAS (single threaded in parallel on Julia Threads) on NERSC Perlmutter (AMD 2x \[AMD EPYC 7763\] 64 cores x 2 hyperthreads per core) …

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## [Unable to install latest version of package in general registry](https://discourse.julialang.org/t/unable-to-install-latest-version-of-package-in-general-registry/130206)

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**Author:** [@Kirby\_Zhang](https://discourse.julialang.org/u/Kirby_Zhang)\
**Replies:** 2\
**Last updated:** [June 25, 2025, 3:41pm UTC](https://discourse.julialang.org/t/unable-to-install-latest-version-of-package-in-general-registry/130206 "2025-06-25T15:41:48Z")

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I’m specifically having trouble with SQLite\_jll@3.49. I’m using Julia 1.10. This is the SQLite\_jll.jl’s project.toml name = "SQLite\_jll" uuid = "76ed43ae-9a5d-5a62-8c75-30186b810ce8" version = "3.49.0+0" \[deps\] JLLWra…

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## [Literal expression for array of vectors](https://discourse.julialang.org/t/literal-expression-for-array-of-vectors/130184)

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**Author:** [@Sevi](https://discourse.julialang.org/u/Sevi)\
**Replies:** 12\
**Last updated:** [June 25, 2025, 1:06pm UTC](https://discourse.julialang.org/t/literal-expression-for-array-of-vectors/130184 "2025-06-25T13:06:12Z")

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Is there an array literal that gives me this object (and a variation with some integer elements in some of the vectors)? julia\> ... 3×5 Matrix{Vector{Int64}}: \[\] \[\] \[\] \[\] \[\] \[\] \[\] \[\] \[\] \[\] \[\] \[\] \[\] \[\] \[\] …

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## [Table disappearing from duckdb database?](https://discourse.julialang.org/t/table-disappearing-from-duckdb-database/130172)

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**Author:** [@floswald](https://discourse.julialang.org/u/floswald)\
**Replies:** 2\
**Last updated:** [June 25, 2025, 9:31am UTC](https://discourse.julialang.org/t/table-disappearing-from-duckdb-database/130172 "2025-06-25T09:31:11Z")

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I have an esoteric bug. I see this: # persistent database backed by file. function with\_db(f::Function) con = DBInterface.connect(DuckDB.DB, \_DB\_PATH) try return f(con) finally DBInterface.cl…

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## [Is it possible to search the julia registry for a function](https://discourse.julialang.org/t/is-it-possible-to-search-the-julia-registry-for-a-function/130182)

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**Author:** [@brianguenter](https://discourse.julialang.org/u/brianguenter)\
**Replies:** 5\
**Last updated:** [June 25, 2025, 12:16am UTC](https://discourse.julialang.org/t/is-it-possible-to-search-the-julia-registry-for-a-function/130182 "2025-06-25T00:16:08Z")

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Is there a tool that will search the packages in the Julia registry for a function name? I sometimes come across online examples that use a Julia function I would also like to use but can’t find the package that contain…

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## [Is \`Core.Compiler.return\_type\` foldable?](https://discourse.julialang.org/t/is-core-compiler-return-type-foldable/130173)

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**Author:** [@MilesCranmer](https://discourse.julialang.org/u/MilesCranmer)\
**Replies:** 19\
**Last updated:** [June 24, 2025, 10:27pm UTC](https://discourse.julialang.org/t/is-core-compiler-return-type-foldable/130173 "2025-06-24T22:27:53Z")

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Let’s say I want to introduce the following utility function in my library so I have a way of type stable get!ing on generic dictionaries: function stable\_get!(f::F, dict, key) where {F} return get!(f, dict, key)::(…

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## [Error adding package from local registry: , Class:SSH, failed to set hostkey preference](https://discourse.julialang.org/t/error-adding-package-from-local-registry-class-ssh-failed-to-set-hostkey-preference/130183)

<div class="topic-metadata">

**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 3\
**Last updated:** [June 24, 2025, 9:42pm UTC](https://discourse.julialang.org/t/error-adding-package-from-local-registry-class-ssh-failed-to-set-hostkey-preference/130183 "2025-06-24T21:42:10Z")

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I’ve been working with a local registry on a Windows computer for a while. After an update, I receive the following error: (Environment) pkg\> add TrueAndErrorModels Resolving package versions... Cloning \[260ba6b…

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## [Add elements to tuples or arrays](https://discourse.julialang.org/t/add-elements-to-tuples-or-arrays/75885)

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**Author:** [@Leticia-maria](https://discourse.julialang.org/u/Leticia-maria)\
**Replies:** 32\
**Last updated:** [June 24, 2025, 9:39pm UTC](https://discourse.julialang.org/t/add-elements-to-tuples-or-arrays/75885 "2025-06-24T21:39:03Z")

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Hi everyone, do you know a way to have this working on Julia REPL? \>\>\> a = \[1,2,3\] \>\>\> a + \[4\] \[1, 2, 3, 4\]

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## [The package \*\*FowardDiff.jl\*\* could not load because it failed to initialize](https://discourse.julialang.org/t/the-package-fowarddiff-jl-could-not-load-because-it-failed-to-initialize/130180)

<div class="topic-metadata">

**Author:** [@Miguel](https://discourse.julialang.org/u/Miguel)\
**Replies:** 3\
**Last updated:** [June 24, 2025, 9:16pm UTC](https://discourse.julialang.org/t/the-package-fowarddiff-jl-could-not-load-because-it-failed-to-initialize/130180 "2025-06-24T21:16:50Z")

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The package FowardDiff.jl could not load because it failed to initialize. That’s not nice! Things you could try: \*\*\* Restart the notebook.\*\* \*\*\* Try a different Julia version.\*\* \*\*\* Contact the developers of FowardDi…

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## [Modifying subentries in a Vector{SVector}, @set and reinterpret](https://discourse.julialang.org/t/modifying-subentries-in-a-vector-svector-set-and-reinterpret/130178)

<div class="topic-metadata">

**Author:** [@eldee](https://discourse.julialang.org/u/eldee)\
**Replies:** 1\
**Last updated:** [June 24, 2025, 7:41pm UTC](https://discourse.julialang.org/t/modifying-subentries-in-a-vector-svector-set-and-reinterpret/130178 "2025-06-24T19:41:58Z")

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Hi, Most of the time it makes conceptually more sense to store some data as a Vector{SVector{Float64, 3}} v as opposed to a Matrix{Float64} M of size (3, n). However, this makes updating (sub)entries more difficult. I.…

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## [Optional argument in macro](https://discourse.julialang.org/t/optional-argument-in-macro/130057)

<div class="topic-metadata">

**Author:** [@alex180500](https://discourse.julialang.org/u/alex180500)\
**Replies:** 8\
**Last updated:** [June 24, 2025, 12:46pm UTC](https://discourse.julialang.org/t/optional-argument-in-macro/130057 "2025-06-24T12:46:48Z")

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I’m creating my custom progress bar for my ML related loop. It’s based on ProgressMeter.jl. The macro takes an argument as input that is a dictionary associating names to vectors of data that I’m saving during the comput…

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