# New to Julia

**URL:** https://discourse.julialang.org/c/first-steps/8.md?page=10

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

**Page:** 11

---

## [Function signature with vector types](https://discourse.julialang.org/t/function-signature-with-vector-types/131704)

<div class="topic-metadata">

**Author:** [@Mastomaki](https://discourse.julialang.org/u/Mastomaki)\
**Replies:** 1\
**Last updated:** [August 19, 2025, 11:18am UTC](https://discourse.julialang.org/t/function-signature-with-vector-types/131704 "2025-08-19T11:18:18Z")

</div>

Suppose I have a function which plots timeseries stored in TSFrames.jl TSFrames. plot\_multirowts(x::Vector{TSFrame}}, seriesnames::Vector{String}) Sometimes, such as when subsetting dataframes, my data will have type V…

---

## [General Q's about Julia](https://discourse.julialang.org/t/general-qs-about-julia/130438)

<div class="topic-metadata">

**Author:** [@skypuppy](https://discourse.julialang.org/u/skypuppy)\
**Replies:** 16\
**Last updated:** [August 18, 2025, 10:38am UTC](https://discourse.julialang.org/t/general-qs-about-julia/130438 "2025-08-18T10:38:41Z")

</div>

Been “learning” Julia for a couple years now, off and on. It is a fascinating language and I wish to learn more. I’m on my 4th book (7 if you count E-books) and still don’t have basics down to my liking. I’m wondering…

---

## [Precompile package causing missing-from-cache errors](https://discourse.julialang.org/t/precompile-package-causing-missing-from-cache-errors/21747)

<div class="topic-metadata">

**Author:** [@Egwene\_al\_Vere](https://discourse.julialang.org/u/Egwene_al_Vere)\
**Replies:** 0\
**Last updated:** [March 11, 2019, 5:52pm UTC](https://discourse.julialang.org/t/precompile-package-causing-missing-from-cache-errors/21747 "2019-03-11T17:52:13Z")

</div>

As an example, (tested with an empty .julia folder), after precompile some package compile\_incremental(:Makie) and launch julia with the -J /path/to/precompiled/sysimg switch, loading other package can fail, e.g. usi…

---

## [Questions about Symbolics: remove small constant terms](https://discourse.julialang.org/t/questions-about-symbolics-remove-small-constant-terms/131595)

<div class="topic-metadata">

**Author:** [@agascoig](https://discourse.julialang.org/u/agascoig)\
**Replies:** 7\
**Last updated:** [August 15, 2025, 6:13pm UTC](https://discourse.julialang.org/t/questions-about-symbolics-remove-small-constant-terms/131595 "2025-08-15T18:13:49Z")

</div>

I have the following symbolic expression with small terms in Julia: (2.23606797749979 - 2.220446049250313e-16im)\*(x\[1\] + x\[4\]) + (-2.23606797749979 + 2.220446049250313e-16im)\*x\[2\] + (-2.23606797749979 + 2.22044604925031…

---

## [Load subfolder in src like in python](https://discourse.julialang.org/t/load-subfolder-in-src-like-in-python/131609)

<div class="topic-metadata">

**Author:** [@Cyan](https://discourse.julialang.org/u/Cyan)\
**Replies:** 4\
**Last updated:** [August 14, 2025, 5:33pm UTC](https://discourse.julialang.org/t/load-subfolder-in-src-like-in-python/131609 "2025-08-14T17:33:42Z")

</div>

Hi, all. I am wondering how I can load a folder as a submodule in Julia, similar to how it is done in Python. For example, I want to load the modules in SubModuleA in the form of MyPackage.SubModuleA.file\_a\_1 and MyPack…

---

## [Verner 9 Runge Kutta Interpolator Issue](https://discourse.julialang.org/t/verner-9-runge-kutta-interpolator-issue/131591)

<div class="topic-metadata">

**Author:** [@may7even](https://discourse.julialang.org/u/may7even)\
**Replies:** 3\
**Last updated:** [August 14, 2025, 4:40am UTC](https://discourse.julialang.org/t/verner-9-runge-kutta-interpolator-issue/131591 "2025-08-14T04:40:09Z")

</div>

Hello, I am trying to implement the vern9 runge kutta method for a side project, and so far, everything has been good, except for the interpolation of the states for a dense output. For some reason, when compared with a …

---

## [Linter/formatter for naming conventions?](https://discourse.julialang.org/t/linter-formatter-for-naming-conventions/131539)

<div class="topic-metadata">

**Author:** [@DanielSussman](https://discourse.julialang.org/u/DanielSussman)\
**Replies:** 1\
**Last updated:** [August 13, 2025, 8:20pm UTC](https://discourse.julialang.org/t/linter-formatter-for-naming-conventions/131539 "2025-08-13T20:20:21Z")

</div>

Hi all, I’m working on writing more idiomatic Julia code and trying to adhere to a common style. I know this is a relatively minor detail, but for whatever reason – old habits die hard, I guess! – I consistently fail to…

---

## [Multidispatch based on value of positional argument](https://discourse.julialang.org/t/multidispatch-based-on-value-of-positional-argument/131584)

<div class="topic-metadata">

**Author:** [@Snowy](https://discourse.julialang.org/u/Snowy)\
**Replies:** 4\
**Last updated:** [August 13, 2025, 4:35pm UTC](https://discourse.julialang.org/t/multidispatch-based-on-value-of-positional-argument/131584 "2025-08-13T16:35:55Z")

</div>

Hi, Just to make sure I understand multidispatch correctly here: There is no way to multidispatch based on a value in a positional argument, correct? For example, something like: function multidispatch(x,y,string\_argu…

---

## [Error when downloading package -- Failed to clone from gitlab.com](https://discourse.julialang.org/t/error-when-downloading-package-failed-to-clone-from-gitlab-com/130032)

<div class="topic-metadata">

**Author:** [@Snowy](https://discourse.julialang.org/u/Snowy)\
**Replies:** 10\
**Last updated:** [August 13, 2025, 6:14pm UTC](https://discourse.julialang.org/t/error-when-downloading-package-failed-to-clone-from-gitlab-com/130032 "2025-08-13T18:14:42Z")

</div>

Hi all, I’m trying to install MLJ.jl and am running into an error when installing the package: ERROR: failed to clone from https://gitlab.com/ExpandingMan/ShowCases.jl.git, error: GitError(Code:ERROR, Class:OS, failed …

---

## [Adjust the decimals in scientific notation with Plots.jl](https://discourse.julialang.org/t/adjust-the-decimals-in-scientific-notation-with-plots-jl/131555)

<div class="topic-metadata">

**Author:** [@kraqbi](https://discourse.julialang.org/u/kraqbi)\
**Replies:** 8\
**Last updated:** [August 13, 2025, 3:24pm UTC](https://discourse.julialang.org/t/adjust-the-decimals-in-scientific-notation-with-plots-jl/131555 "2025-08-13T15:24:10Z")

</div>

Hello! I try to publish my figures so I need to edit them as nicely as possible. I have trouble adjusting the format of my ylabel. I would like to keep a scientific notation, but Plots.jl is automatically set to a two…

---

## [An IDE interface for Windows 7](https://discourse.julialang.org/t/an-ide-interface-for-windows-7/131317)

<div class="topic-metadata">

**Author:** [@hack3rcon](https://discourse.julialang.org/u/hack3rcon)\
**Replies:** 23\
**Last updated:** [August 11, 2025, 6:43pm UTC](https://discourse.julialang.org/t/an-ide-interface-for-windows-7/131317 "2025-08-11T18:43:34Z")

</div>

Hello, I managed to install Julia on Windows 7, but I’m having trouble setting up VSCodium 1.70.2: Trying to locate Julia binary... Juliaup not found, locating Julia by other means. No Julia executable was identified. …

---

## [Asynchronous tasks vs multi-threading](https://discourse.julialang.org/t/asynchronous-tasks-vs-multi-threading/131485)

<div class="topic-metadata">

**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 16\
**Last updated:** [August 10, 2025, 10:48pm UTC](https://discourse.julialang.org/t/asynchronous-tasks-vs-multi-threading/131485 "2025-08-10T22:48:01Z")

</div>

Parallel is a section of Julia’s doc containing the following 2 subsections Asynchronous “tasks”, or coroutines Multi-threading I notice that setting JULIA\_NUM\_THREADS to \>1 (proper physical multi-threading) is only r…

---

## [A problem of PkgTemplate of \`Base.retry\_load\_extensions()\`](https://discourse.julialang.org/t/a-problem-of-pkgtemplate-of-base-retry-load-extensions/131513)

<div class="topic-metadata">

**Author:** [@Cyan](https://discourse.julialang.org/u/Cyan)\
**Replies:** 1\
**Last updated:** [August 10, 2025, 4:54pm UTC](https://discourse.julialang.org/t/a-problem-of-pkgtemplate-of-base-retry-load-extensions/131513 "2025-08-10T16:54:11Z")

</div>

Hi, all. I use PkgTemplate to create a local package. When I using my package, the error shows up: Error: Error during loading of extension FillArraysStatisticsExt of FillArrays, use \`Base.retry\_load\_extensions()\` to re…

---

## [Is this an AI hallucination or my misunderstanding of Julia syntax?](https://discourse.julialang.org/t/is-this-an-ai-hallucination-or-my-misunderstanding-of-julia-syntax/131363)

<div class="topic-metadata">

**Author:** [@pvc](https://discourse.julialang.org/u/pvc)\
**Replies:** 6\
**Last updated:** [August 10, 2025, 10:08pm UTC](https://discourse.julialang.org/t/is-this-an-ai-hallucination-or-my-misunderstanding-of-julia-syntax/131363 "2025-08-10T22:08:33Z")

</div>

Just starting with Julia/VSCode - new to both so not quite sure where best to post this question. I have an “invalid identifier” error in my first program which is diagnosed by GitHub CoPilot as below. I suspect this i…

---

## [Javis: Error in the first tutorial ERROR: UndefVarError: \`Object\` not defined in \`Main\`](https://discourse.julialang.org/t/javis-error-in-the-first-tutorial-error-undefvarerror-object-not-defined-in-main/131467)

<div class="topic-metadata">

**Author:** [@tdm](https://discourse.julialang.org/u/tdm)\
**Replies:** 3\
**Last updated:** [August 8, 2025, 8:11pm UTC](https://discourse.julialang.org/t/javis-error-in-the-first-tutorial-error-undefvarerror-object-not-defined-in-main/131467 "2025-08-08T20:11:23Z")

</div>

I am following the steps in the (very well written) Javis first tutorial: Tutorial 1: Making Your First Javis Animation! · Javis.jl There are errors right off the bat when I try simple things like: julia\> Background(1:…

---

## [RigidBodySim.jl: Working setup on macOS (Julia 1.9+) with browser-based MeshCat visualization?](https://discourse.julialang.org/t/rigidbodysim-jl-working-setup-on-macos-julia-1-9-with-browser-based-meshcat-visualization/131452)

<div class="topic-metadata">

**Author:** [@drsiegmund](https://discourse.julialang.org/u/drsiegmund)\
**Replies:** 2\
**Last updated:** [August 8, 2025, 5:49pm UTC](https://discourse.julialang.org/t/rigidbodysim-jl-working-setup-on-macos-julia-1-9-with-browser-based-meshcat-visualization/131452 "2025-08-08T17:49:35Z")

</div>

Hi everyone, I’m currently setting up \`RigidBodySim.jl\` and \`RigidBodyDynamics.jl\` on a modern macOS system (MacBook Air M2, macOS Sonoma) using Julia 1.9.4 and 1.10.2. My goal is to get a complete and stable simulatio…

---

## [Performant table representation](https://discourse.julialang.org/t/performant-table-representation/129880)

<div class="topic-metadata">

**Author:** [@Gesee](https://discourse.julialang.org/u/Gesee)\
**Replies:** 11\
**Last updated:** [August 8, 2025, 1:33pm UTC](https://discourse.julialang.org/t/performant-table-representation/129880 "2025-08-08T13:33:21Z")

</div>

Actually I am trying to represent a table in Julia. Each column has a name and we should be able to add new column on the fly. Getting column and row should be fast since these are frequent operations on my work. Is th…

---

## [C:\\Users\\MMMM\\.julia\\artifacts\\GUID\\bin\\librsvg-2-2.dll is either not designed to run on Windows or it contains an error](https://discourse.julialang.org/t/c-users-mmmm-julia-artifacts-guid-bin-librsvg-2-2-dll-is-either-not-designed-to-run-on-windows-or-it-contains-an-error/131465)

<div class="topic-metadata">

**Author:** [@tdm](https://discourse.julialang.org/u/tdm)\
**Replies:** 7\
**Last updated:** [August 8, 2025, 7:14am UTC](https://discourse.julialang.org/t/c-users-mmmm-julia-artifacts-guid-bin-librsvg-2-2-dll-is-either-not-designed-to-run-on-windows-or-it-contains-an-error/131465 "2025-08-08T07:14:54Z")

</div>

Anytime I am trying to add a package that uses vector graphics, it fails precompilation with the window popup error: “C:\\Users\\MMMM.julia\\artifacts\\GUID\\bin\\librsvg-2-2.dll is either not designed to run on Windows or it…

---

## [How can I restart Julia](https://discourse.julialang.org/t/how-can-i-restart-julia/129840)

<div class="topic-metadata">

**Author:** [@Smara\_Kazenango](https://discourse.julialang.org/u/Smara_Kazenango)\
**Replies:** 9\
**Last updated:** [August 5, 2025, 12:37pm UTC](https://discourse.julialang.org/t/how-can-i-restart-julia/129840 "2025-08-05T12:37:54Z")

</div>

What command can I run to restart Julia and does this have impact on any of the packages already installed.

---

## [How to pack jl files into a local module?](https://discourse.julialang.org/t/how-to-pack-jl-files-into-a-local-module/131357)

<div class="topic-metadata">

**Author:** [@Cyan](https://discourse.julialang.org/u/Cyan)\
**Replies:** 3\
**Last updated:** [August 5, 2025, 8:55am UTC](https://discourse.julialang.org/t/how-to-pack-jl-files-into-a-local-module/131357 "2025-08-05T08:55:21Z")

</div>

Hi, all. I have several .jl files. I want to pack them into a local module and install it into my environment via pkg. How can I make it?

---

## [JuliaLang and Windows 7](https://discourse.julialang.org/t/julialang-and-windows-7/131140)

<div class="topic-metadata">

**Author:** [@hack3rcon](https://discourse.julialang.org/u/hack3rcon)\
**Replies:** 7\
**Last updated:** [August 3, 2025, 6:42am UTC](https://discourse.julialang.org/t/julialang-and-windows-7/131140 "2025-08-03T06:42:51Z")

</div>

Hello, Can I install the latest version of JuliaLang on Windows 7 x64? Thank you.

---

## [Thread setup time eating up all parallel improvement?](https://discourse.julialang.org/t/thread-setup-time-eating-up-all-parallel-improvement/131214)

<div class="topic-metadata">

**Author:** [@JJMerelo](https://discourse.julialang.org/u/JJMerelo)\
**Replies:** 21\
**Last updated:** [August 1, 2025, 9:16am UTC](https://discourse.julialang.org/t/thread-setup-time-eating-up-all-parallel-improvement/131214 "2025-08-01T09:16:31Z")

</div>

Hi, Just experimenting a bit with parallel execution, using this example here, a straightforward parallel-and-collect results. The issue here is that it’s not really improving wallclock time, although it’s spending le…

---

## [Converting Dict to DataFrames](https://discourse.julialang.org/t/converting-dict-to-dataframes/131248)

<div class="topic-metadata">

**Author:** [@Snowy](https://discourse.julialang.org/u/Snowy)\
**Replies:** 4\
**Last updated:** [July 31, 2025, 4:42pm UTC](https://discourse.julialang.org/t/converting-dict-to-dataframes/131248 "2025-07-31T16:42:23Z")

</div>

Hi all, I’m sure this is pretty simple but it’s tripping me up. Say I have a dictionary as such: using DataFrames using Dates Dates\_to\_remember = Dict(:Birthday=\> Set(\[ Date("2021-01-15"), Date("1991-08-30"),…

---

## [Using PyPlot vs Plots](https://discourse.julialang.org/t/using-pyplot-vs-plots/28313)

<div class="topic-metadata">

**Author:** [@henry2004y](https://discourse.julialang.org/u/henry2004y)\
**Replies:** 8\
**Last updated:** [July 31, 2025, 10:40am UTC](https://discourse.julialang.org/t/using-pyplot-vs-plots/28313 "2025-07-31T10:40:38Z")

</div>

Hi, When I first learned Julia, I was guided towards the Plots package for visualization. Even though it has multiple options of the backend libraries, I found it hard for me as a user who is more familiar with the MATL…

---

## [Output of @benchmark to string or table?](https://discourse.julialang.org/t/output-of-benchmark-to-string-or-table/27977)

<div class="topic-metadata">

**Author:** [@nmatzke](https://discourse.julialang.org/u/nmatzke)\
**Replies:** 3\
**Last updated:** [August 28, 2019, 2:20am UTC](https://discourse.julialang.org/t/output-of-benchmark-to-string-or-table/27977 "2019-08-28T02:20:15Z")

</div>

Hi all! This is a very simple question but I can’t find an easy answer. Any help appreciated! I am trying to @benchmark the speed of a function over several orders-of-magnitude of inputs. I would like to just do a for-…

---

## [\[10757\] signal 11 (1): Segmentation fault](https://discourse.julialang.org/t/10757-signal-11-1-segmentation-fault/131139)

<div class="topic-metadata">

**Author:** [@redti](https://discourse.julialang.org/u/redti)\
**Replies:** 37\
**Last updated:** [July 30, 2025, 4:42pm UTC](https://discourse.julialang.org/t/10757-signal-11-1-segmentation-fault/131139 "2025-07-30T16:42:04Z")

</div>

Hi, I’m completely new to Julia, I’d like to begging by expressing my appreciation for the FreeBSD installation package to the Dev responsible for it. I’m under FreeBSD 14.3 patch 1. I’m using KDE, Plasma 6.4.3. The w…

---

## [Animation keeps changing xlims ylims](https://discourse.julialang.org/t/animation-keeps-changing-xlims-ylims/131181)

<div class="topic-metadata">

**Author:** [@Leibniz](https://discourse.julialang.org/u/Leibniz)\
**Replies:** 2\
**Last updated:** [July 29, 2025, 6:31pm UTC](https://discourse.julialang.org/t/animation-keeps-changing-xlims-ylims/131181 "2025-07-29T18:31:05Z")

</div>

Greetings, I have been struggling for hours to create an animation (particles in a box) where the xlims and ylims of the plot window remain fixed during the run. @userplot SystemPlot @recipe function f(sp::SystemPlo…

---

## [Receive the success status of \`pop!(Set, element)\`](https://discourse.julialang.org/t/receive-the-success-status-of-pop-set-element/131089)

<div class="topic-metadata">

**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 6\
**Last updated:** [July 29, 2025, 7:54am UTC](https://discourse.julialang.org/t/receive-the-success-status-of-pop-set-element/131089 "2025-07-29T07:54:44Z")

</div>

Continuing the discussion from Receive the success status of \`push!(Set, element)\`: The following defined method # collect \`e\` into \`S\`, return success status collect!(S, e) = !in!(e, S) should have an inverse, which …

---

## [Best way to parallelize for loop with given thread number](https://discourse.julialang.org/t/best-way-to-parallelize-for-loop-with-given-thread-number/131141)

<div class="topic-metadata">

**Author:** [@Leibniz](https://discourse.julialang.org/u/Leibniz)\
**Replies:** 2\
**Last updated:** [July 29, 2025, 3:32am UTC](https://discourse.julialang.org/t/best-way-to-parallelize-for-loop-with-given-thread-number/131141 "2025-07-29T03:32:21Z")

</div>

Greetings, what is the most efficient way to parallelize a for loop if I only want to use n of N active global threads? The way I understand it, Threads.@threads for it in 1:nthreads will use all available threads wh…

---

## [Rrule for zygote](https://discourse.julialang.org/t/rrule-for-zygote/131069)

<div class="topic-metadata">

**Author:** [@mary](https://discourse.julialang.org/u/mary)\
**Replies:** 7\
**Last updated:** [July 29, 2025, 1:37am UTC](https://discourse.julialang.org/t/rrule-for-zygote/131069 "2025-07-29T01:37:23Z")

</div>

Hi, I am using rrule for gradient calculation in zygote. I defined a function which calculates the gradients and I just call that function inside the entire gradient calculation. Can zygote handle this type of rule? fun…

[Previous page](https://discourse.julialang.org/c/first-steps/8.md?page=9)

[Next page](https://discourse.julialang.org/c/first-steps/8.md?page=11)