# Latest

**URL:** https://discourse.julialang.org/latest.md?page=281

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

**Page:** 282

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## [Why does append!(df1, df2) return a DataFrame, as well as modify the argument df1?](https://discourse.julialang.org/t/why-does-append-df1-df2-return-a-dataframe-as-well-as-modify-the-argument-df1/122329)

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**Author:** [@world-peace](https://discourse.julialang.org/u/world-peace)\
**Replies:** 22\
**Last updated:** [November 7, 2024, 1:03pm UTC](https://discourse.julialang.org/t/why-does-append-df1-df2-return-a-dataframe-as-well-as-modify-the-argument-df1/122329 "2024-11-07T13:03:21Z")

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It seems like the append! function, as defined in the DataFrames package both returns a value and modifies the value of one of its arguments. This seems strange and I am struggling to understand why this happens. I pic…

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## [Programming with rich text (Jupyter notebooks or similar?) on remote servers](https://discourse.julialang.org/t/programming-with-rich-text-jupyter-notebooks-or-similar-on-remote-servers/119249)

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**Author:** [@albertomercurio](https://discourse.julialang.org/u/albertomercurio)\
**Replies:** 20\
**Last updated:** [November 7, 2024, 1:03pm UTC](https://discourse.julialang.org/t/programming-with-rich-text-jupyter-notebooks-or-similar-on-remote-servers/119249 "2024-11-07T13:03:36Z")

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Hello, I have been programming in Julia since 2020. I first used JupyterLab with IJulia.jl, and now I’m working with VSCode, still with IJulia.jl. In this last case, I actually don’t like programming using the Julia ex…

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## [Is \`empty!\` O(1)?](https://discourse.julialang.org/t/is-empty-o-1/122367)

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**Author:** [@guoyongzhi](https://discourse.julialang.org/u/guoyongzhi)\
**Replies:** 4\
**Last updated:** [November 7, 2024, 12:35pm UTC](https://discourse.julialang.org/t/is-empty-o-1/122367 "2024-11-07T12:35:49Z")

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The doc page says that empty! is nearly costless (and O(1)) for types that support this kind of preallocation. But the code of empty! and \_deleteend! show that it’s in O(n) complexity. The \_unsetindex! in iteration b…

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## [A chainrule for multi-threaded map](https://discourse.julialang.org/t/a-chainrule-for-multi-threaded-map/122357)

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**Author:** [@Tomas\_Pevny](https://discourse.julialang.org/u/Tomas_Pevny)\
**Replies:** 3\
**Last updated:** [November 7, 2024, 12:32pm UTC](https://discourse.julialang.org/t/a-chainrule-for-multi-threaded-map/122357 "2024-11-07T12:32:13Z")

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Hi All, does anyone has a a chainrule for multi-threaded map? It should be “relatively” easy to implement by adapting ChainRules.jl/src/rulesets/Base/base.jl at 955941ec31aab80942658f517a2e024b3e7c812b · JuliaDiff/Chain…

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## [@threads vs @spawn](https://discourse.julialang.org/t/threads-vs-spawn/51168)

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**Author:** [@Bryan\_So](https://discourse.julialang.org/u/Bryan_So)\
**Replies:** 9\
**Last updated:** [November 7, 2024, 12:29pm UTC](https://discourse.julialang.org/t/threads-vs-spawn/51168 "2024-11-07T12:29:28Z")

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Hi, would appreciate some feedback about this issue. I’m trying to understand the difference between @threads and @spawn. I think the former is easy to understand. I have an experiment shuffling cards, many many times…

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## [Makie (GeoMakie + GLMakie) arrows doesn't use 'alpha=' parameter](https://discourse.julialang.org/t/makie-geomakie-glmakie-arrows-doesnt-use-alpha-parameter/122339)

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**Author:** [@RobbesU](https://discourse.julialang.org/u/RobbesU)\
**Replies:** 2\
**Last updated:** [November 6, 2024, 7:23pm UTC](https://discourse.julialang.org/t/makie-geomakie-glmakie-arrows-doesnt-use-alpha-parameter/122339 "2024-11-06T19:23:28Z")

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The docs for Makie arrows state alpha Defaults to 1.0 The alpha value of the colormap or color attribute. Multiple alphas like in plot(alpha=0.2, color=(:red, 0.5), will get multiplied. However, it appears the color…

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## [UndefVarError Main.xxx issue](https://discourse.julialang.org/t/undefvarerror-main-xxx-issue/122061)

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**Author:** [@Math027d](https://discourse.julialang.org/u/Math027d)\
**Replies:** 9\
**Last updated:** [November 7, 2024, 10:52am UTC](https://discourse.julialang.org/t/undefvarerror-main-xxx-issue/122061 "2024-11-07T10:52:05Z")

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I have just bought a new computer, which is a MacBook Air with an M3 chip. Ever since installing Julia and adding the extension via Visual Studio Code I receive errors such as "UndefVarError: ‘…’ not defined in ‘Main.xxx…

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## [What interface to implement for \`round(x, digits=n)\` to work?](https://discourse.julialang.org/t/what-interface-to-implement-for-round-x-digits-n-to-work/122372)

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**Author:** [@barucden](https://discourse.julialang.org/u/barucden)\
**Replies:** 2\
**Last updated:** [November 7, 2024, 9:32am UTC](https://discourse.julialang.org/t/what-interface-to-implement-for-round-x-digits-n-to-work/122372 "2024-11-07T09:32:38Z")

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There is a section in the documentation that explains what methods to implement to support rounding on a new type: Apparently, one needs to implement round(x::ObjType, r::RoundingMode). The section even includes an exa…

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## [AlphaVantage.jl - A New Package for Getting Market Data into Julia](https://discourse.julialang.org/t/alphavantage-jl-a-new-package-for-getting-market-data-into-julia/42657)

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**Author:** [@dm13450](https://discourse.julialang.org/u/dm13450)\
**Replies:** 21\
**Last updated:** [November 7, 2024, 9:18am UTC](https://discourse.julialang.org/t/alphavantage-jl-a-new-package-for-getting-market-data-into-julia/42657 "2024-11-07T09:18:44Z")

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Hot off the general repository is a new package for using the AlphaVantage API in Julia. AlphaVantage provides a free tier of stock, fx and cyrpto data, with even intraday level of detail. You can use this package to ea…

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## [How can I change the Pluto notebook theme?](https://discourse.julialang.org/t/how-can-i-change-the-pluto-notebook-theme/122333)

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**Author:** [@selinguler94](https://discourse.julialang.org/u/selinguler94)\
**Replies:** 3\
**Last updated:** [November 7, 2024, 8:52am UTC](https://discourse.julialang.org/t/how-can-i-change-the-pluto-notebook-theme/122333 "2024-11-07T08:52:53Z")

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I genuinely failed to change the theme and I need help.

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## [PSA: Breaking change how juliaup interacts with JULIA\_DEPOT\_PATH](https://discourse.julialang.org/t/psa-breaking-change-how-juliaup-interacts-with-julia-depot-path/106497)

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**Author:** [@davidanthoff](https://discourse.julialang.org/u/davidanthoff)\
**Replies:** 12\
**Last updated:** [November 7, 2024, 7:57am UTC](https://discourse.julialang.org/t/psa-breaking-change-how-juliaup-interacts-with-julia-depot-path/106497 "2024-11-07T07:57:07Z")

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This is a short note that I am about to push a breaking update for Juliaup to everyone that changes how Juliaup interacts with JULIA\_DEPOT\_PATH. This is a pretty esoteric topic, so for most users of Juliaup, it is probab…

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## [How do i import custom python modules in Julia](https://discourse.julialang.org/t/how-do-i-import-custom-python-modules-in-julia/122370)

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**Author:** [@hangita101](https://discourse.julialang.org/u/hangita101)\
**Replies:** 1\
**Last updated:** [November 7, 2024, 6:57am UTC](https://discourse.julialang.org/t/how-do-i-import-custom-python-modules-in-julia/122370 "2024-11-07T06:57:54Z")

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I am trying to import my custom python module in julia I have stored the module in the same directory as the julia file I am using PyCall but its shows that module does not exist

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## [Many subplots with one sublot consisting of a secondary y axis](https://discourse.julialang.org/t/many-subplots-with-one-sublot-consisting-of-a-secondary-y-axis/120827)

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**Author:** [@AUK1939](https://discourse.julialang.org/u/AUK1939)\
**Replies:** 2\
**Last updated:** [November 7, 2024, 3:30am UTC](https://discourse.julialang.org/t/many-subplots-with-one-sublot-consisting-of-a-secondary-y-axis/120827 "2024-11-07T03:30:03Z")

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I was trying to extend the following example to incude more subplots I want to create subplots in which one subplot has a secondary y-axis. Everything works fine in the 2 sub plot case. my\_plot = PlotlyJS.make\_subplot…

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## [What are the current (late 2024) best practices for CLI development?](https://discourse.julialang.org/t/what-are-the-current-late-2024-best-practices-for-cli-development/122013)

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**Author:** [@kevbonham](https://discourse.julialang.org/u/kevbonham)\
**Replies:** 3\
**Last updated:** [November 7, 2024, 3:12am UTC](https://discourse.julialang.org/t/what-are-the-current-late-2024-best-practices-for-cli-development/122013 "2024-11-07T03:12:28Z")

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Say someone is developing a package, and wants to include some command line interface. What are current best practices / ways to do this? My motivation here is twofold - I am actively working on such a project, and also …

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## [Legend covers the yaxis](https://discourse.julialang.org/t/legend-covers-the-yaxis/122334)

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**Author:** [@Stephen](https://discourse.julialang.org/u/Stephen)\
**Replies:** 2\
**Last updated:** [November 7, 2024, 1:23am UTC](https://discourse.julialang.org/t/legend-covers-the-yaxis/122334 "2024-11-07T01:23:53Z")

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using Plots plotlyjs() plot!( M2, x\_台湾, 货币\_台湾.M2./货币\_台湾.全體銀行放款餘額, label = "M2/全体银行放款余额", fg\_legend = :transparent, legend = :bottomleft, tickfontsize = 11, xticks = xt…

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## [Number contours in PlotlyJS.contour](https://discourse.julialang.org/t/number-contours-in-plotlyjs-contour/122360)

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**Author:** [@miguelborrero](https://discourse.julialang.org/u/miguelborrero)\
**Replies:** 2\
**Last updated:** [November 7, 2024, 12:28am UTC](https://discourse.julialang.org/t/number-contours-in-plotlyjs-contour/122360 "2024-11-07T00:28:21Z")

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Hi there, I would like to produce a contour plot of a quadratic function and I found a nice way to do so with PlotlyJS.contour but I am not able to customize the number of contours. It seems like the documentation gives …

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## [Reducing Channel Lock Contention with Batches](https://discourse.julialang.org/t/reducing-channel-lock-contention-with-batches/122215)

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**Author:** [@mrufsvold](https://discourse.julialang.org/u/mrufsvold)\
**Replies:** 4\
**Last updated:** [November 6, 2024, 11:59pm UTC](https://discourse.julialang.org/t/reducing-channel-lock-contention-with-batches/122215 "2024-11-06T23:59:44Z")

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This has been asked before, but it looks like it didn’t go anywhere. Channels are very powerful, but the lock overhead makes it slow for iterating. Bundling items into batches before take!/put! would help with this overh…

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## [A Julia I Ching hexagram generator using a QRNG](https://discourse.julialang.org/t/a-julia-i-ching-hexagram-generator-using-a-qrng/121405)

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**Author:** [@Barzin](https://discourse.julialang.org/u/Barzin)\
**Replies:** 2\
**Last updated:** [November 6, 2024, 9:12pm UTC](https://discourse.julialang.org/t/a-julia-i-ching-hexagram-generator-using-a-qrng/121405 "2024-11-06T21:12:12Z")

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Friends and fellas, I present the most off-topicest of posts: you can now use Julia to throw the I Ching using completely indeterministic quantum random numbers. https://github.com/BarzinL/Qing May your divining hand b…

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## [What's the syntax to create a collapsable section on Discourse?](https://discourse.julialang.org/t/whats-the-syntax-to-create-a-collapsable-section-on-discourse/122354)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 1\
**Last updated:** [November 6, 2024, 8:15pm UTC](https://discourse.julialang.org/t/whats-the-syntax-to-create-a-collapsable-section-on-discourse/122354 "2024-11-06T20:15:44Z")

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Different thing: what is the mark-up syntax for inserting this collapsible code? Ah… figured it out \<details\> \<summary\> Click \</summary\> ...test \</details\>

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## [MTK - equation with sqrt(x) vs. x^0.5?](https://discourse.julialang.org/t/mtk-equation-with-sqrt-x-vs-x-0-5/122341)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 8\
**Last updated:** [November 6, 2024, 8:06pm UTC](https://discourse.julialang.org/t/mtk-equation-with-sqrt-x-vs-x-0-5/122341 "2024-11-06T20:06:35Z")

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I run a model (MTK) where one term of an equation does log(x^0.5). This seems to work sometimes, but also crashes for some parameter values when I do Monte Carlo simulation. If I change the term to log(sqrt(x)), the sim…

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## [Splat operator](https://discourse.julialang.org/t/splat-operator/122351)

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**Author:** [@martin\_sanchez](https://discourse.julialang.org/u/martin_sanchez)\
**Replies:** 3\
**Last updated:** [November 6, 2024, 8:03pm UTC](https://discourse.julialang.org/t/splat-operator/122351 "2024-11-06T20:03:39Z")

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Going to edit the question: My doubt is why, even when I use the splat operator in a function definition, I can still refer to it as an iterator. To be more concrete: function mysum(args...) sum=0 for i in args …

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## [Extending type functionality in Python and Julia](https://discourse.julialang.org/t/extending-type-functionality-in-python-and-julia/122222)

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**Author:** [@Nikos\_Gianniotis](https://discourse.julialang.org/u/Nikos_Gianniotis)\
**Replies:** 7\
**Last updated:** [November 6, 2024, 7:35pm UTC](https://discourse.julialang.org/t/extending-type-functionality-in-python-and-julia/122222 "2024-11-06T19:35:18Z")

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I have been using Julia for the last 9 years. As one of the few (if not the only one) users of Julia in the institute I work, I was asked to give a talk about it. One of the things I want to talk about is the ease with w…

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## [Open- or Closed-source for AI?](https://discourse.julialang.org/t/open-or-closed-source-for-ai/117779)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 1\
**Last updated:** [November 6, 2024, 6:45pm UTC](https://discourse.julialang.org/t/open-or-closed-source-for-ai/117779 "2024-11-06T18:45:12Z")

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Keep the code behind AI open, say two entrepreneurs (economist.com) vs. Not all AI models should be freely available, argues a legal scholar (economist.com)

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## [Minimal loading of OrdinaryDiffEq](https://discourse.julialang.org/t/minimal-loading-of-ordinarydiffeq/122335)

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**Author:** [@svretina](https://discourse.julialang.org/u/svretina)\
**Replies:** 4\
**Last updated:** [November 6, 2024, 5:32pm UTC](https://discourse.julialang.org/t/minimal-loading-of-ordinarydiffeq/122335 "2024-11-06T17:32:34Z")

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I was wondering if it is possible (or if there are plans to do so) to load a minimal subspace of functionalities that one needs. The precompilation times are high and for my usage they deter me from using it. I would lik…

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## [Why does \`A .= sign.(view(A, diagind(A))) .\* A\` allocate?](https://discourse.julialang.org/t/why-does-a-sign-view-a-diagind-a-a-allocate/122332)

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**Author:** [@zsoerenm](https://discourse.julialang.org/u/zsoerenm)\
**Replies:** 9\
**Last updated:** [November 6, 2024, 5:23pm UTC](https://discourse.julialang.org/t/why-does-a-sign-view-a-diagind-a-a-allocate/122332 "2024-11-06T17:23:47Z")

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Hey, consider this function: using LinearAlgebra function correct\_sign(A) A .= sign.(view(A, diagind(A))) .\* A end Why would that allocate? Am I missing something? using BenchmarkTools B = randn(3,3) @btime correct…

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## [\[ANN\] CryptoGroups.jl: A Versatile, Type-Safe Cryptographic Group Library](https://discourse.julialang.org/t/ann-cryptogroups-jl-a-versatile-type-safe-cryptographic-group-library/119200)

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**Author:** [@Janis\_Erdmanis](https://discourse.julialang.org/u/Janis_Erdmanis)\
**Replies:** 1\
**Last updated:** [November 6, 2024, 4:27pm UTC](https://discourse.julialang.org/t/ann-cryptogroups-jl-a-versatile-type-safe-cryptographic-group-library/119200 "2024-11-06T16:27:31Z")

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Hello, everyone :partying\_face: I’m thrilled to announce the release of CryptoGroups.jl, a package that brings a versatile and type-safe implementation of cryptographic groups to Julia. This library has been a long-term…

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## [How to access mingw64 files in pluto notebook?](https://discourse.julialang.org/t/how-to-access-mingw64-files-in-pluto-notebook/122340)

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**Author:** [@selinguler94](https://discourse.julialang.org/u/selinguler94)\
**Replies:** 0\
**Last updated:** [November 6, 2024, 4:35pm UTC](https://discourse.julialang.org/t/how-to-access-mingw64-files-in-pluto-notebook/122340 "2024-11-06T16:35:22Z")

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I want to execute some fortran files so windows isn’t working for that, I have mingw64 to execute fortran but I can not access the files now. C:/Users/name /c/Users/name I replaced the first with the second but can’t …

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## [DCMotor example @named output throwing Latex error on analysis points](https://discourse.julialang.org/t/dcmotor-example-named-output-throwing-latex-error-on-analysis-points/121752)

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**Author:** [@RobbesU](https://discourse.julialang.org/u/RobbesU)\
**Replies:** 10\
**Last updated:** [November 6, 2024, 3:57pm UTC](https://discourse.julialang.org/t/dcmotor-example-named-output-throwing-latex-error-on-analysis-points/121752 "2024-11-06T15:57:11Z")

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Running the ModelingtoolkitStandardLibrary example DCMotor https://docs.sciml.ai/ModelingToolkitStandardLibrary/stable/tutorials/dc\_motor\_pi/ Running the code as is it throws below error in the @named model = DCMotor(): …

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## [PackageCompiler warnings](https://discourse.julialang.org/t/packagecompiler-warnings/122338)

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**Author:** [@ohmsweetohm1](https://discourse.julialang.org/u/ohmsweetohm1)\
**Replies:** 0\
**Last updated:** [November 6, 2024, 3:15pm UTC](https://discourse.julialang.org/t/packagecompiler-warnings/122338 "2024-11-06T15:15:43Z")

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I’m seeing many warnings like these: Warning: .drectve \`-exclude-symbols:jl\_pgcstack\_key\_slot ' unrecognized Warning: .drectve \`-exclude-symbols:jl\_tls\_offset ' unrecognized Warning: .drectve \`-exclude-symbols:jl\_ptls\_t…

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## [Documenter.jl is not documenting any changes](https://discourse.julialang.org/t/documenter-jl-is-not-documenting-any-changes/94781)

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**Author:** [@mdogan](https://discourse.julialang.org/u/mdogan)\
**Replies:** 17\
**Last updated:** [November 6, 2024, 10:41am UTC](https://discourse.julialang.org/t/documenter-jl-is-not-documenting-any-changes/94781 "2024-11-06T10:41:57Z")

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I don’t know what I am doing wrong. I download the project Example.jl from GitHub. JuliaLang/Example.jl: Example Julia package repo. (github.com) I only changed the content of the Example.jl under src folder; just remo…

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