# General Usage

**URL:** https://discourse.julialang.org/c/usage/6.md?page=50

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**Page:** 51

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## [How to add information of unregistered packages on Project.toml instead of Manifest.toml?](https://discourse.julialang.org/t/how-to-add-information-of-unregistered-packages-on-project-toml-instead-of-manifest-toml/114773)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 7\
**Last updated:** [July 23, 2025, 12:02pm UTC](https://discourse.julialang.org/t/how-to-add-information-of-unregistered-packages-on-project-toml-instead-of-manifest-toml/114773 "2025-07-23T12:02:53Z")

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Hi, I am working on a set of packages that I don’t want yet to register. The issue is that when I add one as a dependency of another one, like add git@github.com:forestmod/GenFSM\_resources.jl.git in the environment of G…

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## [DocumenterVitepress examples (list of packages that use it)](https://discourse.julialang.org/t/documentervitepress-examples-list-of-packages-that-use-it/130795)

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**Author:** [@digital\_carver](https://discourse.julialang.org/u/digital_carver)\
**Replies:** 5\
**Last updated:** [July 23, 2025, 11:32am UTC](https://discourse.julialang.org/t/documentervitepress-examples-list-of-packages-that-use-it/130795 "2025-07-23T11:32:07Z")

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I made an appreciation post for DocumenterVitepress on Slack a couple of months ago, and several people shared examples of docs generated using it in the replies. (For context, DocumenterVitepress is a special backend fo…

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## [\-0.0 == 0.0, but issorted(\[0.0, -0.0\]) returns false](https://discourse.julialang.org/t/0-0-0-0-but-issorted-0-0-0-0-returns-false/130966)

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**Author:** [@heliosdrm](https://discourse.julialang.org/u/heliosdrm)\
**Replies:** 4\
**Last updated:** [July 23, 2025, 8:43am UTC](https://discourse.julialang.org/t/0-0-0-0-but-issorted-0-0-0-0-returns-false/130966 "2025-07-23T08:43:44Z")

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There is some kind of sorting order between positive and negative zeros of float types: julia\> issorted(\[-0.0, 0.0\]) true julia\> issorted(\[0.0, -0.0\]) false But this is not observed when those numbers are compared to …

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## [How to parallelize \`lu!\` factorization?](https://discourse.julialang.org/t/how-to-parallelize-lu-factorization/130933)

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**Author:** [@Leon\_Lampret](https://discourse.julialang.org/u/Leon_Lampret)\
**Replies:** 15\
**Last updated:** [July 22, 2025, 8:40pm UTC](https://discourse.julialang.org/t/how-to-parallelize-lu-factorization/130933 "2025-07-22T20:40:05Z")

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I have a generic implementation of the LU factorization of a rectangular matrix: function \_swap\_col!(X, j1, j2) @inbounds begin m=size(X,1); (j1==j2 || m\<1) && return nothing; @simd for i=1:m…

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## [How best to preallocate memory for repeated use](https://discourse.julialang.org/t/how-best-to-preallocate-memory-for-repeated-use/130814)

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**Author:** [@Joris\_Pinkse](https://discourse.julialang.org/u/Joris_Pinkse)\
**Replies:** 5\
**Last updated:** [July 22, 2025, 4:21pm UTC](https://discourse.julialang.org/t/how-best-to-preallocate-memory-for-repeated-use/130814 "2025-07-22T16:21:41Z")

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Hello, I’m trying to reduce memory allocations. The pattern is simple: I need to redo a similar problem that requires a fair bit of memory many times. So I’m preallocating sufficient memory for the largest problem and…

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## [Define struct with two fields that have the same abstract type but different specialization](https://discourse.julialang.org/t/define-struct-with-two-fields-that-have-the-same-abstract-type-but-different-specialization/130945)

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**Author:** [@zsoerenm](https://discourse.julialang.org/u/zsoerenm)\
**Replies:** 4\
**Last updated:** [July 22, 2025, 3:30pm UTC](https://discourse.julialang.org/t/define-struct-with-two-fields-that-have-the-same-abstract-type-but-different-specialization/130945 "2025-07-22T15:30:59Z")

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Let’s say I want to have a struct with two fields that both are arrays. I want both array types to be the same e.g. Array, Array or CuArray, CuArray But the specialization should be different like the first one holds f…

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## [Nothing values in constraints](https://discourse.julialang.org/t/nothing-values-in-constraints/130937)

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**Author:** [@Henk\_de\_Man](https://discourse.julialang.org/u/Henk_de_Man)\
**Replies:** 4\
**Last updated:** [July 22, 2025, 2:28pm UTC](https://discourse.julialang.org/t/nothing-values-in-constraints/130937 "2025-07-22T14:28:51Z")

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How to handle variables that have “null” value, in constraint expressions. For example in Excel when we have an expression a\*b + c, and b = empty, then Excel will just return c. How can we handle such expressions in cons…

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## [Macro utilities for working with function definitions in 2025](https://discourse.julialang.org/t/macro-utilities-for-working-with-function-definitions-in-2025/130687)

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**Author:** [@CameronBieganek](https://discourse.julialang.org/u/CameronBieganek)\
**Replies:** 17\
**Last updated:** [July 22, 2025, 2:20pm UTC](https://discourse.julialang.org/t/macro-utilities-for-working-with-function-definitions-in-2025/130687 "2025-07-22T14:20:53Z")

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What are the recommended tools these days for working with function definition expressions in macros? I’m aware of ExprTools.jl and MacroTools.jl, but I don’t know how maintained they are and whether those packages or ot…

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## [Fixed-structure CHOLMOD with in-place \`set\_nonzeros!\`](https://discourse.julialang.org/t/fixed-structure-cholmod-with-in-place-set-nonzeros/130922)

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**Author:** [@luke-kiernan](https://discourse.julialang.org/u/luke-kiernan)\
**Replies:** 3\
**Last updated:** [July 22, 2025, 3:03am UTC](https://discourse.julialang.org/t/fixed-structure-cholmod-with-in-place-set-nonzeros/130922 "2025-07-22T03:03:22Z")

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I have a large sparse matrix. Its nonzeros change over the course of the problem, but its structure doesn’t. I want to do repeated in-place Cholesky factorizations, re-using the symbolic factorization and modifying the n…

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## [Tetgen jll: Update pretty please](https://discourse.julialang.org/t/tetgen-jll-update-pretty-please/130925)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 0\
**Last updated:** [July 22, 2025, 1:44am UTC](https://discourse.julialang.org/t/tetgen-jll-update-pretty-please/130925 "2025-07-22T01:44:33Z")

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Whoever is responsible for Tetgen jll: It is stuck on 1.5.3 and that means it probably has serious bugs that have been fixed in 1.6.0. Would it be possible to update this? Also: Is it possible to update the jll manually…

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## [Julia run code problems](https://discourse.julialang.org/t/julia-run-code-problems/130899)

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**Author:** [@AndoStat](https://discourse.julialang.org/u/AndoStat)\
**Replies:** 2\
**Last updated:** [July 21, 2025, 1:07pm UTC](https://discourse.julialang.org/t/julia-run-code-problems/130899 "2025-07-21T13:07:55Z")

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I try to use VS Code with Julia language support in it and run nuts unto errors and issues, code cant be run due ongoing problems with Julia Language Server which VS Code try to start and then crashes flawlessly, somethi…

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## [Generated function with array of expressions](https://discourse.julialang.org/t/generated-function-with-array-of-expressions/129122)

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**Author:** [@PharmCat](https://discourse.julialang.org/u/PharmCat)\
**Replies:** 3\
**Last updated:** [May 23, 2025, 2:19pm UTC](https://discourse.julialang.org/t/generated-function-with-array-of-expressions/129122 "2025-05-23T14:19:52Z")

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Hi! I want to wake generated function like this: d = Dict(:a =\> :(y+1), :b =\> :(y+1)) func(y) = NamedTuple{eval(Expr(:tuple, :(keys(d)...)))}((eval(x) for x in values(d))) or like this: d = Dict(:a =\> :(y+1), :n =\> :…

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## [Tyler in VSCode Notebook Prints Two Figures with 1 Call](https://discourse.julialang.org/t/tyler-in-vscode-notebook-prints-two-figures-with-1-call/130823)

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**Author:** [@elipivo](https://discourse.julialang.org/u/elipivo)\
**Replies:** 4\
**Last updated:** [July 20, 2025, 6:32pm UTC](https://discourse.julialang.org/t/tyler-in-vscode-notebook-prints-two-figures-with-1-call/130823 "2025-07-20T18:32:05Z")

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I am using Tyler with CairoMakie in a Julia notebook in VSCode. I’m curious if there is a way to get Tyler to only display the figure with the tiles, not the first empty one.

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## [Why doesn't Random.seed! allocate for StableRNGs.LehmerRNG?](https://discourse.julialang.org/t/why-doesnt-random-seed-allocate-for-stablerngs-lehmerrng/130621)

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**Author:** [@RoyW](https://discourse.julialang.org/u/RoyW)\
**Replies:** 1\
**Last updated:** [July 20, 2025, 9:36am UTC](https://discourse.julialang.org/t/why-doesnt-random-seed-allocate-for-stablerngs-lehmerrng/130621 "2025-07-20T09:36:09Z")

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I ran the following code on my machine: import StableRNGs using BenchmarkTools, Random const T = Float64 rng = StableRNGs.LehmerRNG(0) rng2 = Random.Xoshiro(0) rng3 = Random.MersenneTwister(0) @btime randn($rng, T) @…

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## [Accessing values from XML files using XML.jl](https://discourse.julialang.org/t/accessing-values-from-xml-files-using-xml-jl/130832)

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**Author:** [@jarredclloyd](https://discourse.julialang.org/u/jarredclloyd)\
**Replies:** 5\
**Last updated:** [July 19, 2025, 10:07pm UTC](https://discourse.julialang.org/t/accessing-values-from-xml-files-using-xml-jl/130832 "2025-07-19T22:07:40Z")

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Hello, I’m struggling to understand how to use XML.jl to read a file and acquire data from it by using the tags at specific depths. Here is an abbreviated version of the XML that contains the basic structure of the XML …

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## [How to change "julia\>" prompt to "\>" in console and vscode?](https://discourse.julialang.org/t/how-to-change-julia-prompt-to-in-console-and-vscode/130861)

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**Author:** [@Alex1](https://discourse.julialang.org/u/Alex1)\
**Replies:** 8\
**Last updated:** [July 19, 2025, 4:19pm UTC](https://discourse.julialang.org/t/how-to-change-julia-prompt-to-in-console-and-vscode/130861 "2025-07-19T16:19:39Z")

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And hide Julia initial info too, so the repl will be nice and clean.

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## [Custom hash not called for field in another struct – expected?](https://discourse.julialang.org/t/custom-hash-not-called-for-field-in-another-struct-expected/130869)

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**Author:** [@MilesCranmer](https://discourse.julialang.org/u/MilesCranmer)\
**Replies:** 4\
**Last updated:** [July 19, 2025, 2:56pm UTC](https://discourse.julialang.org/t/custom-hash-not-called-for-field-in-another-struct-expected/130869 "2025-07-19T14:56:16Z")

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The Julia docs say: But when I do this, it seems to ignore my custom hash function in certain contexts: julia\> struct Foo end julia\> Base.hash(::Foo, h::UInt) = error() The following calls are what I would ex…

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## [Avoiding a copy after removing missings from a vector](https://discourse.julialang.org/t/avoiding-a-copy-after-removing-missings-from-a-vector/130866)

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**Author:** [@s-baumann](https://discourse.julialang.org/u/s-baumann)\
**Replies:** 9\
**Last updated:** [July 19, 2025, 2:27pm UTC](https://discourse.julialang.org/t/avoiding-a-copy-after-removing-missings-from-a-vector/130866 "2025-07-19T14:27:34Z")

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In Julia I am trying to write a function that will (without copying) compute something from two vectors. As an example think of Pearson correlation (although it is not that). What I have got is: function get\_valid\_entr…

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## [\[solved\] How to load Modules on demand? To speed up](https://discourse.julialang.org/t/solved-how-to-load-modules-on-demand-to-speed-up/130862)

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**Author:** [@Alex1](https://discourse.julialang.org/u/Alex1)\
**Replies:** 8\
**Last updated:** [July 19, 2025, 5:50am UTC](https://discourse.julialang.org/t/solved-how-to-load-modules-on-demand-to-speed-up/130862 "2025-07-19T05:50:04Z")

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I want to speed up running Julia script. Some code executed rarely and require heavy libraries. The problem is ERROR: LoadError: syntax: "import" expression not at top level. Eval doesn’t work ether, it complains abou…

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## [Tyler Plotting Error](https://discourse.julialang.org/t/tyler-plotting-error/130816)

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**Author:** [@elipivo](https://discourse.julialang.org/u/elipivo)\
**Replies:** 8\
**Last updated:** [July 18, 2025, 8:50pm UTC](https://discourse.julialang.org/t/tyler-plotting-error/130816 "2025-07-18T20:50:50Z")

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I’m getting the following error using Tyler right out of the box. The versions of the packages are… (temp) pkg\> st Status \`(path)\\Project.toml\` ⌃ \[e9467ef8\] GLMakie v0.10.18 ⌃ \[e170d443\] Tyler v0.1.5 ⌃ \[e9467ef8\] GLMaki…

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## [A gotcha with OffsetArrays](https://discourse.julialang.org/t/a-gotcha-with-offsetarrays/130858)

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**Author:** [@Joris\_Pinkse](https://discourse.julialang.org/u/Joris_Pinkse)\
**Replies:** 3\
**Last updated:** [July 18, 2025, 7:45pm UTC](https://discourse.julialang.org/t/a-gotcha-with-offsetarrays/130858 "2025-07-18T19:45:37Z")

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With using OffsetArrays import Base: length, size, lastindex, firstindex, eachindex, getindex, setindex!, show, display struct Polly{T} \<: AbstractVector{ T } d :: Int a :: OffsetArray{ T, 1 } functio…

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## [Reading csv files with missing lines](https://discourse.julialang.org/t/reading-csv-files-with-missing-lines/130853)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 2\
**Last updated:** [July 18, 2025, 5:45pm UTC](https://discourse.julialang.org/t/reading-csv-files-with-missing-lines/130853 "2025-07-18T17:45:35Z")

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I have to read the following csv file: #Turbine Time(s) dt(s) nacelle yaw angle (degrees) 0 20000 0.5 255 1 20000 0.5 255 2 20000 0.5 255 3 20000 0.5 255 4 20000 0.5 255 5 20000 0.5 255 6 20000 0.5 255 7 20000 …

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## [Why can svgplugin.dll not be found? (for PackageCompiler binary, bundled artifacts)](https://discourse.julialang.org/t/why-can-svgplugin-dll-not-be-found-for-packagecompiler-binary-bundled-artifacts/130848)

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**Author:** [@testmax](https://discourse.julialang.org/u/testmax)\
**Replies:** 1\
**Last updated:** [July 18, 2025, 5:31pm UTC](https://discourse.julialang.org/t/why-can-svgplugin-dll-not-be-found-for-packagecompiler-binary-bundled-artifacts/130848 "2025-07-18T17:31:47Z")

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Hello all! I would like to understand, how the DLLs are loaded by the EXE generated with PackageCompiler.jl. The issue is that I have a problem with a compiled program and the GR\_jll.jl DLLs. Specifically, when exporti…

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## [Plots.jl, GR.jl broken due to GR\_jll v0.69.1+1](https://discourse.julialang.org/t/plots-jl-gr-jl-broken-due-to-gr-jll-v0-69-1-1/89708)

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**Author:** [@mkitti](https://discourse.julialang.org/u/mkitti)\
**Replies:** 5\
**Last updated:** [July 18, 2025, 5:33pm UTC](https://discourse.julialang.org/t/plots-jl-gr-jl-broken-due-to-gr-jll-v0-69-1-1/89708 "2025-07-18T17:33:18Z")

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Hi all, I may have broken Plots.jl and GR.jl by introducing v0.69.1+1 of GR\_jll. In particular, you might see an issue when trying to use any GR plugins. For example, the bug creates an issue when using SVG output withi…

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## [Basic question about type alias](https://discourse.julialang.org/t/basic-question-about-type-alias/130844)

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**Author:** [@Nikos\_Gianniotis](https://discourse.julialang.org/u/Nikos_Gianniotis)\
**Replies:** 5\
**Last updated:** [July 18, 2025, 2:40pm UTC](https://discourse.julialang.org/t/basic-question-about-type-alias/130844 "2025-07-18T14:40:50Z")

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For the first time, I defined my own type alias and was surprised by the following behaviour: const VecScalar{T\<:Number} = Tuple{Vector{T}, T} x::VecScalar{Float64} = (\[1.0, 2.0\], 3.0) # works as expected. x::VecScal…

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## [Cleaning ImageMorphology boundary data](https://discourse.julialang.org/t/cleaning-imagemorphology-boundary-data/130561)

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**Author:** [@solace](https://discourse.julialang.org/u/solace)\
**Replies:** 8\
**Last updated:** [July 18, 2025, 1:59pm UTC](https://discourse.julialang.org/t/cleaning-imagemorphology-boundary-data/130561 "2025-07-18T13:59:09Z")

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Hi all, this is my first post on discourse so apologies in advance if I haven’t formatted things correctly. I have read the “Please read: make it easier to help you” discussion. I have a matrix of float values represent…

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## [Franklin: utils.jl produces JavaScript scripts locally but not on GitHub Pages](https://discourse.julialang.org/t/franklin-utils-jl-produces-javascript-scripts-locally-but-not-on-github-pages/130836)

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**Author:** [@fusion809](https://discourse.julialang.org/u/fusion809)\
**Replies:** 1\
**Last updated:** [July 18, 2025, 10:53am UTC](https://discourse.julialang.org/t/franklin-utils-jl-produces-javascript-scripts-locally-but-not-on-github-pages/130836 "2025-07-18T10:53:35Z")

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I’ve been trying to modularize my Franklin-powered website’s code by using Julia to build pieces of JavaScript code in the website that are fairly repetitive. To achieve this, I used this Julia code in my utils.jl file: …

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## [Weave.jl report generation fails in PackageCompiler.jl App](https://discourse.julialang.org/t/weave-jl-report-generation-fails-in-packagecompiler-jl-app/130841)

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**Author:** [@apurvdarji](https://discourse.julialang.org/u/apurvdarji)\
**Replies:** 0\
**Last updated:** [July 18, 2025, 9:29am UTC](https://discourse.julialang.org/t/weave-jl-report-generation-fails-in-packagecompiler-jl-app/130841 "2025-07-18T09:29:00Z")

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I’m encountering an issue when generating a report from a compiled application that uses Weave.jl, which I built with PackageCompiler.jl. Initially, I received the following error: ┌ Warning: Error generating report! │…

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## [Gradual Julia-ization of Python libraries](https://discourse.julialang.org/t/gradual-julia-ization-of-python-libraries/117828)

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**Author:** [@MilesCranmer](https://discourse.julialang.org/u/MilesCranmer)\
**Replies:** 36\
**Last updated:** [July 18, 2025, 9:07am UTC](https://discourse.julialang.org/t/gradual-julia-ization-of-python-libraries/117828 "2025-07-18T09:07:26Z")

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Context Python has a large community\[1\]. However, many of its most-used numerical libraries – numpy, scipy, scikit-learn, pandas, pytorch, jax – are not written in Python. Instead, a frontend API is written in Python, hi…

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## [Keeping local Manifest.toml's up to date](https://discourse.julialang.org/t/keeping-local-manifest-tomls-up-to-date/130694)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 9\
**Last updated:** [July 18, 2025, 7:50am UTC](https://discourse.julialang.org/t/keeping-local-manifest-tomls-up-to-date/130694 "2025-07-18T07:50:05Z")

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Generally, I do not commit Manifest.toml, docs/Manifest.toml and test/Manifest.toml (where applicable) to git repositories for packages. However, as a result, sometimes these become out of date for local clones of packa…

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