# General Usage

**URL:** https://discourse.julialang.org/c/usage/6.md?page=28

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**Page:** 29

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## [Flat shading in Makie](https://discourse.julialang.org/t/flat-shading-in-makie/15216)

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**Author:** [@krcools](https://discourse.julialang.org/u/krcools)\
**Replies:** 4\
**Last updated:** [November 24, 2025, 11:20pm UTC](https://discourse.julialang.org/t/flat-shading-in-makie/15216 "2025-11-24T23:20:04Z")

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Is it possible to have per face coloring/lighting for Makie.mesh (as opposed to per vertex)? This is more appropriate for the visualization of polyhedra or other shapes that have sharp corners and for the visualization o…

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## [Print all outputs of Jupyter Cell](https://discourse.julialang.org/t/print-all-outputs-of-jupyter-cell/134095)

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**Author:** [@Ismam](https://discourse.julialang.org/u/Ismam)\
**Replies:** 1\
**Last updated:** [November 24, 2025, 10:13pm UTC](https://discourse.julialang.org/t/print-all-outputs-of-jupyter-cell/134095 "2025-11-24T22:13:26Z")

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Is there a Julia equivalent to the below python code which enables Jupyter notebooks to print all outputs. from IPython.core.interactiveshell import InteractiveShell InteractiveShell.ast\_node\_interactivity = "all" I kn…

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## [Permute NamedTuple based on names of another NamedTuple](https://discourse.julialang.org/t/permute-namedtuple-based-on-names-of-another-namedtuple/134088)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 3\
**Last updated:** [November 24, 2025, 7:51pm UTC](https://discourse.julialang.org/t/permute-namedtuple-based-on-names-of-another-namedtuple/134088 "2025-11-24T19:51:19Z")

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I would like to perform a calculation in type space: given a NamedTuple{M,K} type, permute its fields so that the names match a NamedTuple{N}. Example: julia\> p1(NamedTuple{(:a,:b)}, NamedTuple{(:b,:a),Tuple{Int,Float64…

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## [Registering a Julia Package](https://discourse.julialang.org/t/registering-a-julia-package/134081)

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**Author:** [@ekneller](https://discourse.julialang.org/u/ekneller)\
**Replies:** 2\
**Last updated:** [November 24, 2025, 5:09pm UTC](https://discourse.julialang.org/t/registering-a-julia-package/134081 "2025-11-24T17:09:54Z")

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I am trying to register my first Julia package called EarthBox and have passed all of the AutoMerge requirements. However, there appears to be a non-package issue with the registration process. See this link for details …

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## [Updating via JuliaUp](https://discourse.julialang.org/t/updating-via-juliaup/134082)

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**Author:** [@Boris](https://discourse.julialang.org/u/Boris)\
**Replies:** 2\
**Last updated:** [November 24, 2025, 4:12pm UTC](https://discourse.julialang.org/t/updating-via-juliaup/134082 "2025-11-24T16:12:39Z")

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So, I wanted to go to 1.12.2 as I saw the post that it is available and when I use list, I don’t see it. Am I missing something? \> juliaup status Default Channel Version Update ---------------------…

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## [Query compiler's effect modeling](https://discourse.julialang.org/t/query-compilers-effect-modeling/134079)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 2\
**Last updated:** [November 24, 2025, 2:15pm UTC](https://discourse.julialang.org/t/query-compilers-effect-modeling/134079 "2025-11-24T14:15:46Z")

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Before using @assume\_effects, is it possible to check what the compiler already figured out about a function? I can of course do it very indirectly (call the function and see what’s eliminated), but it would be great to…

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## [Get Lagrange multipliers from Ipopt with Optimization.jl](https://discourse.julialang.org/t/get-lagrange-multipliers-from-ipopt-with-optimization-jl/134074)

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**Author:** [@nico](https://discourse.julialang.org/u/nico)\
**Replies:** 1\
**Last updated:** [November 24, 2025, 1:41pm UTC](https://discourse.julialang.org/t/get-lagrange-multipliers-from-ipopt-with-optimization-jl/134074 "2025-11-24T13:41:53Z")

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Hi everyone! I’m working with the Julia packages Optimization.jl and Ipopt.jl to solve a nonlinear programming (NLP) problem. I’m successfully solving the problem, but I need to extract the final Lagrange multipliers (…

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## [Mooncake, Turing, and CI](https://discourse.julialang.org/t/mooncake-turing-and-ci/134067)

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**Author:** [@marcobonici](https://discourse.julialang.org/u/marcobonici)\
**Replies:** 3\
**Last updated:** [November 24, 2025, 11:20am UTC](https://discourse.julialang.org/t/mooncake-turing-and-ci/134067 "2025-11-24T11:20:45Z")

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Hello, I finally am switching to DifferentiationInterface for the tests of a package of mine and I don’t think I could be happier! It lets me quickly write tests in a coherent manner, to try different backends. Amazing…

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## [\[juliacall\] Invoking functions with names not allowed by Python](https://discourse.julialang.org/t/juliacall-invoking-functions-with-names-not-allowed-by-python/134056)

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**Author:** [@tobydriscoll](https://discourse.julialang.org/u/tobydriscoll)\
**Replies:** 1\
**Last updated:** [November 23, 2025, 10:52pm UTC](https://discourse.julialang.org/t/juliacall-invoking-functions-with-names-not-allowed-by-python/134056 "2025-11-23T22:52:48Z")

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I’d like to make a Python wrapper for a Julia package that implements methods for Base operators like + and \*, among others. The wrapper class should use juliacall to create the object and then simply pass method calls t…

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## [Why can't a tuple of types have an abstract type with Type selectors?](https://discourse.julialang.org/t/why-cant-a-tuple-of-types-have-an-abstract-type-with-type-selectors/134036)

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**Author:** [@Benny](https://discourse.julialang.org/u/Benny)\
**Replies:** 7\
**Last updated:** [November 23, 2025, 11:12am UTC](https://discourse.julialang.org/t/why-cant-a-tuple-of-types-have-an-abstract-type-with-type-selectors/134036 "2025-11-23T11:12:10Z")

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julia\> 1 isa Int true julia\> (1,) isa Tuple{Int} true julia\> Int isa Type{Int} true julia\> (Int,) isa Tuple{Type{Int}} # ??? false And how does dispatch work if this doesn’t work for method signatures as tuple types? …

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## [Alternative to map() for grouped dataframe?](https://discourse.julialang.org/t/alternative-to-map-for-grouped-dataframe/134038)

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**Author:** [@Quantodeluz](https://discourse.julialang.org/u/Quantodeluz)\
**Replies:** 9\
**Last updated:** [November 22, 2025, 9:42pm UTC](https://discourse.julialang.org/t/alternative-to-map-for-grouped-dataframe/134038 "2025-11-22T21:42:04Z")

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I’m trying to do one quadratic fit per subdataframe on a grouped dataframe (using two of it’s columns obviously), but i can’t use map() to do it because it’s reserved, and doing a list comprehension throws an error becau…

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## [Dagger.jl optimising a two step matrix-vector multiplication](https://discourse.julialang.org/t/dagger-jl-optimising-a-two-step-matrix-vector-multiplication/134030)

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**Author:** [@cneverett](https://discourse.julialang.org/u/cneverett)\
**Replies:** 1\
**Last updated:** [November 22, 2025, 9:23pm UTC](https://discourse.julialang.org/t/dagger-jl-optimising-a-two-step-matrix-vector-multiplication/134030 "2025-11-22T21:23:30Z")

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Hi All, I am attempting to scale some serial code used in my code package Diplodocus.jl to be compatible with HPC systems, following suggestions to try distributing operations using Dagger.jl. My problem (in serial) is …

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## [Jupyter classic](https://discourse.julialang.org/t/jupyter-classic/133844)

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**Author:** [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)\
**Replies:** 4\
**Last updated:** [November 22, 2025, 7:20pm UTC](https://discourse.julialang.org/t/jupyter-classic/133844 "2025-11-22T19:20:48Z")

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Hi, I’m always using jupyer to create my julia notebooks, but always using the classic jupyter, not the jupyterlab one which is very, very igly looking to my eyes. Up until a few days ago I could revert back to the clas…

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## [Stream into JLD2 file](https://discourse.julialang.org/t/stream-into-jld2-file/134025)

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**Author:** [@jlbosse](https://discourse.julialang.org/u/jlbosse)\
**Replies:** 8\
**Last updated:** [November 22, 2025, 11:57am UTC](https://discourse.julialang.org/t/stream-into-jld2-file/134025 "2025-11-22T11:57:48Z")

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I am trying to write a larger than memory dataset to a JLD2 file in a streaming way. That dataset is generated by an iterator of known length and element type. So I thought I could use JLD2.create\_dataset() to create tha…

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## [Reducing over Point objects](https://discourse.julialang.org/t/reducing-over-point-objects/133540)

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**Author:** [@xor0110](https://discourse.julialang.org/u/xor0110)\
**Replies:** 9\
**Last updated:** [November 22, 2025, 10:27am UTC](https://discourse.julialang.org/t/reducing-over-point-objects/133540 "2025-11-22T10:27:25Z")

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Julia has many statistics-computing functions, typically a “reduce” kind of function, that can take either a simple vector, or go over an array and compute the output over row, columns, etc according to the dims paramete…

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## [Missing Tree Hash](https://discourse.julialang.org/t/missing-tree-hash/134039)

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**Author:** [@Chrysoberyl](https://discourse.julialang.org/u/Chrysoberyl)\
**Replies:** 2\
**Last updated:** [November 22, 2025, 8:46am UTC](https://discourse.julialang.org/t/missing-tree-hash/134039 "2025-11-22T08:46:03Z")

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In the versioning file of GNNGraphs: General/G/GNNGraphs/Versions.toml at master · JuliaRegistries/General · GitHub There is this line: \["1.4.2"\] git-tree-sha1 = "b3d3e4edd78a75d90089b4c13df1650895fbc7b2" but after cl…

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## [Why is a \`isfoo(x) = x === foo\` method defined for some singleton types?](https://discourse.julialang.org/t/why-is-a-isfoo-x-x-foo-method-defined-for-some-singleton-types/134018)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 19\
**Last updated:** [November 22, 2025, 1:00am UTC](https://discourse.julialang.org/t/why-is-a-isfoo-x-x-foo-method-defined-for-some-singleton-types/134018 "2025-11-22T01:00:32Z")

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Base and some libraries introduce a function to test for singleton types (ismissing, isnothing) that is basically an application of ===. I am curious about the rationale for this API choice. (Not questioning how it is i…

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## [Confusion about type constraints in where clauses](https://discourse.julialang.org/t/confusion-about-type-constraints-in-where-clauses/134019)

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**Author:** [@Graham\_Gill](https://discourse.julialang.org/u/Graham_Gill)\
**Replies:** 4\
**Last updated:** [November 21, 2025, 11:02pm UTC](https://discourse.julialang.org/t/confusion-about-type-constraints-in-where-clauses/134019 "2025-11-21T23:02:49Z")

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Why this julia\> g(::Type{S}, ::Type{T}) where {T, S\>:T} = (S,T) g (generic function with 1 method) julia\> g(Integer, Int) ERROR: UndefVarError: \`S\` not defined in static parameter matching Suggestion: run Test.detect\_u…

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## [Juliaup (nightly) download not working](https://discourse.julialang.org/t/juliaup-nightly-download-not-working/132411)

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**Author:** [@Palli](https://discourse.julialang.org/u/Palli)\
**Replies:** 2\
**Last updated:** [November 21, 2025, 8:19pm UTC](https://discourse.julialang.org/t/juliaup-nightly-download-not-working/132411 "2025-11-21T20:19:12Z")

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Can other confirm, or if only problem for me locally, know why? \[I’ve done this before, worked then, couldn’t update either so I tried this after removing.\] $ juliaup add nightly Installing Julia latest-linux-x86\_64 Er…

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## [Reinterpret interleaved real and imaginary numbers to an Abstract Vector](https://discourse.julialang.org/t/reinterpret-interleaved-real-and-imaginary-numbers-to-an-abstract-vector/134033)

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**Author:** [@Jake](https://discourse.julialang.org/u/Jake)\
**Replies:** 1\
**Last updated:** [November 21, 2025, 4:19pm UTC](https://discourse.julialang.org/t/reinterpret-interleaved-real-and-imaginary-numbers-to-an-abstract-vector/134033 "2025-11-21T16:19:10Z")

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I am reading interleaved complex data as (abscissa, real, imaginary) numbers in one vector. Elements 1, 4 ,7, … are the abscissa, and elements (2,3), (4,5), … are the (real, imaginary) components of the complex numbers.…

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## [Segmentation fault at rmprocs()](https://discourse.julialang.org/t/segmentation-fault-at-rmprocs/134022)

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**Author:** [@mancolric](https://discourse.julialang.org/u/mancolric)\
**Replies:** 4\
**Last updated:** [November 21, 2025, 3:12pm UTC](https://discourse.julialang.org/t/segmentation-fault-at-rmprocs/134022 "2025-11-21T15:12:36Z")

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Hello, I am trying to run this simple MWE.jl file in a HPC: using Distributed addprocs(2) println("Processes added") rmprocs(workers()) println("Processes removed") If I run julia MWE.jl in my laptop, it works fine.…

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## [Seg fault when using julia (pakcage installation, profiling)](https://discourse.julialang.org/t/seg-fault-when-using-julia-pakcage-installation-profiling/133991)

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**Author:** [@Ahmed\_ALKAF](https://discourse.julialang.org/u/Ahmed_ALKAF)\
**Replies:** 15\
**Last updated:** [November 21, 2025, 2:56pm UTC](https://discourse.julialang.org/t/seg-fault-when-using-julia-pakcage-installation-profiling/133991 "2025-11-21T14:56:15Z")

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Hello, I’m new to Julia so I don’t know if seg faults are a classic thing but anyway, I have one and I don’t know why. I installed Julia using Juliaup I’m on linux, so I just ran the command curl -fsSL https://instal…

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## [Makie：ERROR: MethodError: no method matching create\_dim\_conversion(::Type{Union{Missing, Float64}}) The function \`create\_dim\_conversion\` exists, but no method is defined for this combination of argument types](https://discourse.julialang.org/t/makie-error-methoderror-no-method-matching-create-dim-conversion-type-union-missing-float64-the-function-create-dim-conversion-exists-but-no-method-is-defined-for-this-combination-of-argument-types/131156)

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**Author:** [@dk-zen](https://discourse.julialang.org/u/dk-zen)\
**Replies:** 5\
**Last updated:** [November 21, 2025, 2:39pm UTC](https://discourse.julialang.org/t/makie-error-methoderror-no-method-matching-create-dim-conversion-type-union-missing-float64-the-function-create-dim-conversion-exists-but-no-method-is-defined-for-this-combination-of-argument-types/131156 "2025-11-21T14:39:05Z")

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I upgraded Makie and the code that was working fine before started to give errors. Has anyone encountered this problem? or Would it be better to go back to the previous version? ERROR: MethodError: no method matching c…

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## [Multidimensional array comprehension](https://discourse.julialang.org/t/multidimensional-array-comprehension/134004)

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**Author:** [@fps](https://discourse.julialang.org/u/fps)\
**Replies:** 13\
**Last updated:** [November 21, 2025, 8:31am UTC](https://discourse.julialang.org/t/multidimensional-array-comprehension/134004 "2025-11-21T08:31:59Z")

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I wonder it is possible to get the following matrix with a single array comprehension that’s also efficient to evaluate: (1, 1, 1) (1, 2, 1) (1, 1, 2) (1, 2, 2) (1, 1, 3) (1, 2, 3).... (2, 1, 1) (2, 2, 1) (2, 1, 2) (2…

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## [Is there any way to use cd with multithreading?](https://discourse.julialang.org/t/is-there-any-way-to-use-cd-with-multithreading/133984)

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**Author:** [@eott-siz](https://discourse.julialang.org/u/eott-siz)\
**Replies:** 2\
**Last updated:** [November 21, 2025, 8:00am UTC](https://discourse.julialang.org/t/is-there-any-way-to-use-cd-with-multithreading/133984 "2025-11-21T08:00:53Z")

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I’m currently working on a simulation server for running simulations with our simulation engine. The simulation input is uploaded via a Python flask API, but the simulation code and the code handling execution is in Juli…

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## [Best practices for optimization problems with ODE solves and eigen calls](https://discourse.julialang.org/t/best-practices-for-optimization-problems-with-ode-solves-and-eigen-calls/133995)

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**Author:** [@Gavin-Rockwood](https://discourse.julialang.org/u/Gavin-Rockwood)\
**Replies:** 12\
**Last updated:** [November 21, 2025, 7:47am UTC](https://discourse.julialang.org/t/best-practices-for-optimization-problems-with-ode-solves-and-eigen-calls/133995 "2025-11-21T07:47:22Z")

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I am working on an optimization which has the following structure Build some Hamiltonian large matrices which are functions of the parameters I am optimizing over Project onto the lowest couple of energy levels Calcula…

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## [Problems with GLMakie](https://discourse.julialang.org/t/problems-with-glmakie/133922)

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**Author:** [@Mervyn\_Larrier](https://discourse.julialang.org/u/Mervyn_Larrier)\
**Replies:** 6\
**Last updated:** [November 21, 2025, 2:49am UTC](https://discourse.julialang.org/t/problems-with-glmakie/133922 "2025-11-21T02:49:59Z")

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I’m trying to learn how to use GLMakie having had a lot of success with CairoMakie. But I immediately ran into issues. VSCode is my main text editor, and whereas I’ve never had an issue with CairoMakie, I can’t say the s…

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## [VSC update screwed the REPL?](https://discourse.julialang.org/t/vsc-update-screwed-the-repl/134012)

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**Author:** [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Replies:** 3\
**Last updated:** [November 21, 2025, 1:20am UTC](https://discourse.julialang.org/t/vsc-update-screwed-the-repl/134012 "2025-11-21T01:20:07Z")

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Hi, is it only me or the last VSC update screwed the ability to open the Julia REPL? It happened to me after the last update but even when I installed a September version I was also not able to open the REPL. The big sh…

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## [Very best way to concatenate an array of arrays](https://discourse.julialang.org/t/very-best-way-to-concatenate-an-array-of-arrays/8672)

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**Author:** [@ExpandingMan](https://discourse.julialang.org/u/ExpandingMan)\
**Replies:** 49\
**Last updated:** [November 20, 2025, 11:39pm UTC](https://discourse.julialang.org/t/very-best-way-to-concatenate-an-array-of-arrays/8672 "2025-11-20T23:39:00Z")

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I’ve been wondering about this for a while. Suppose I want to concatenate arrays of arrays. Currently the only way I know of doing that is vcat(A...) (or could be hcat, whatever). My understanding is that this is doub…

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## [JLD2 - load from IOBuffer](https://discourse.julialang.org/t/jld2-load-from-iobuffer/67641)

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**Author:** [@cwiese](https://discourse.julialang.org/u/cwiese)\
**Replies:** 5\
**Last updated:** [November 20, 2025, 9:04pm UTC](https://discourse.julialang.org/t/jld2-load-from-iobuffer/67641 "2025-11-20T21:04:33Z")

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I am not finding a method to load a JLD2 file using JLD2.load() from IOBuffer. This seems basic for saving and loading to cloud like S3 or Azure Blob storage (which is my case). I would like to avoid reading from a REST …

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