# Latest

**URL:** https://discourse.julialang.org/latest.md?page=509

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

**Page:** 510

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## [Getting HiGHs to return when objective value doesn't move](https://discourse.julialang.org/t/getting-highs-to-return-when-objective-value-doesnt-move/103990)

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**Author:** [@nilshg](https://discourse.julialang.org/u/nilshg)\
**Replies:** 7\
**Last updated:** [January 15, 2024, 12:42pm UTC](https://discourse.julialang.org/t/getting-highs-to-return-when-objective-value-doesnt-move/103990 "2024-01-15T12:42:02Z")

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I’m trying to solve a constrained optimization problem with JuMP and HiGHs (this is for an open source package so I want to rely on an open source solver), but for some reason the optimization never terminates although t…

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## [Fosdem 2024](https://discourse.julialang.org/t/fosdem-2024/108826)

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**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 0\
**Last updated:** [January 15, 2024, 12:15pm UTC](https://discourse.julialang.org/t/fosdem-2024/108826 "2024-01-15T12:15:28Z")

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Are any Julians intending to attend the FOSDEM conference in Brussels? FOSDEM 2024 - Home I should be in the HPC Devroom on Saturday. FOSDEM 2024 - HPC, Big Data & Data Science devroom

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## [Struggling with layouting Makie plots](https://discourse.julialang.org/t/struggling-with-layouting-makie-plots/108690)

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**Author:** [@p\_f](https://discourse.julialang.org/u/p_f)\
**Replies:** 4\
**Last updated:** [January 15, 2024, 11:01am UTC](https://discourse.julialang.org/t/struggling-with-layouting-makie-plots/108690 "2024-01-15T11:01:00Z")

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Apologies, this is a very similar question to one I asked yesterday, but a bit different. Apologies as well if the answer is in the docs, but I’m struggling to find it. I’ve been playing around with various combinations …

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## [Access each element in the broadcast operation](https://discourse.julialang.org/t/access-each-element-in-the-broadcast-operation/108728)

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**Author:** [@Afonso\_Britto](https://discourse.julialang.org/u/Afonso_Britto)\
**Replies:** 6\
**Last updated:** [January 15, 2024, 8:11am UTC](https://discourse.julialang.org/t/access-each-element-in-the-broadcast-operation/108728 "2024-01-15T08:11:03Z")

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Is there anyway I can acess the current element I’m iterating through when I use a broadcast operation? I would want to make this code in just one line, so, for every pixel I’m iterating in my image I would want to perfo…

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## [Fastest \`sqrt\` and \`log\` with negative check](https://discourse.julialang.org/t/fastest-sqrt-and-log-with-negative-check/107575)

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**Author:** [@DanDoe](https://discourse.julialang.org/u/DanDoe)\
**Replies:** 17\
**Last updated:** [January 14, 2024, 12:23pm UTC](https://discourse.julialang.org/t/fastest-sqrt-and-log-with-negative-check/107575 "2024-01-14T12:23:15Z")

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NaNMath.jl implements special functions such as sqrt and log which return NaN if called with negative argument. The implementation of sqrt is given by sqrt(x::T) where {T\<:AbstractFloat} = x \< 0.0 ? T(NaN) : Base.sqrt(…

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## [How is it that new Julia programmers tend to abuse type annotations?](https://discourse.julialang.org/t/how-is-it-that-new-julia-programmers-tend-to-abuse-type-annotations/108465)

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**Author:** [@lrnv](https://discourse.julialang.org/u/lrnv)\
**Replies:** 94\
**Last updated:** [January 15, 2024, 7:25am UTC](https://discourse.julialang.org/t/how-is-it-that-new-julia-programmers-tend-to-abuse-type-annotations/108465 "2024-01-15T07:25:06Z")

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Spending some time on this forum and reading around, this strikes me as a recurring mistake of newcomers (me included some time ago of course!): Superfluous type annotations on parameters on function: it looks like peo…

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## [Is it possible to set the attribute of optimizer in the iteration of \_solve\_in\_sequence in Lexicographic?](https://discourse.julialang.org/t/is-it-possible-to-set-the-attribute-of-optimizer-in-the-iteration-of-solve-in-sequence-in-lexicographic/108793)

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**Author:** [@Hongliang\_Yang](https://discourse.julialang.org/u/Hongliang_Yang)\
**Replies:** 5\
**Last updated:** [January 15, 2024, 7:00am UTC](https://discourse.julialang.org/t/is-it-possible-to-set-the-attribute-of-optimizer-in-the-iteration-of-solve-in-sequence-in-lexicographic/108793 "2024-01-15T07:00:00Z")

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For the following code using JuMP import HiGHS import MultiObjectiveAlgorithms as MOA model = JuMP.Model(() -\> MOA.Optimizer(HiGHS.Optimizer)) set\_attribute(model, MOA.Algorithm(), MOA.Lexicographic()) Is it possible…

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## [\[Images.jl\] Projective Transform based on Matrix](https://discourse.julialang.org/t/images-jl-projective-transform-based-on-matrix/108559)

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**Author:** [@lgmendes](https://discourse.julialang.org/u/lgmendes)\
**Replies:** 2\
**Last updated:** [January 15, 2024, 6:43am UTC](https://discourse.julialang.org/t/images-jl-projective-transform-based-on-matrix/108559 "2024-01-15T06:43:18Z")

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How I can apply an Projective Transform (or an Affine) to a image based on a transform matrix ? In phyton I can do this using: tform = transform.ProjectiveTransform(matrix=matrix) An example in Python (from Documentat…

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## [Undefined Variable Error only on Github CI tests](https://discourse.julialang.org/t/undefined-variable-error-only-on-github-ci-tests/108804)

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**Author:** [@Tortar](https://discourse.julialang.org/u/Tortar)\
**Replies:** 1\
**Last updated:** [January 14, 2024, 11:34pm UTC](https://discourse.julialang.org/t/undefined-variable-error-only-on-github-ci-tests/108804 "2024-01-14T23:34:30Z")

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I got this mysterious error on github: Got exception outside of a @test On worker 2: UndefVarError: \`#323#326\` not defined along with other two very similar errors. What is really strange though is that locally …

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## [\[a...\] vs \[a\]](https://discourse.julialang.org/t/a-vs-a/108757)

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**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 7\
**Last updated:** [January 14, 2024, 11:32pm UTC](https://discourse.julialang.org/t/a-vs-a/108757 "2024-01-14T23:32:34Z")

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What does this line of code mean? adds = add isa Union{AbstractArray, Tuple}? \[add...\] : \[add\] Here ‘add’ is supposed to be a vector or a single number.

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## [How to make a Pair Plot in Plots.jl?](https://discourse.julialang.org/t/how-to-make-a-pair-plot-in-plots-jl/53785)

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**Author:** [@TheCedarPrince](https://discourse.julialang.org/u/TheCedarPrince)\
**Replies:** 5\
**Last updated:** [January 14, 2024, 11:19pm UTC](https://discourse.julialang.org/t/how-to-make-a-pair-plot-in-plots-jl/53785 "2024-01-14T23:19:38Z")

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Hey everyone, I feel like I am totally overthinking this but am running into a wall. I was able to make a pairplot using some code from a Makie discussion here. I have been trying to do the same thing using Plots.jl. In…

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## [How to pass flag-like commandline ARGS to julia -e](https://discourse.julialang.org/t/how-to-pass-flag-like-commandline-args-to-julia-e/108797)

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**Author:** [@schlichtanders](https://discourse.julialang.org/u/schlichtanders)\
**Replies:** 2\
**Last updated:** [January 14, 2024, 9:00pm UTC](https://discourse.julialang.org/t/how-to-pass-flag-like-commandline-args-to-julia-e/108797 "2024-01-14T21:00:37Z")

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Hello, I just run into the issue, that julia will interprete flags even if passed after -e. The -- also does not seem to help, because it demands a file, but I really just want the -e and no extra file.

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## [Method not found error](https://discourse.julialang.org/t/method-not-found-error/108760)

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**Author:** [@temp](https://discourse.julialang.org/u/temp)\
**Replies:** 3\
**Last updated:** [January 14, 2024, 8:37pm UTC](https://discourse.julialang.org/t/method-not-found-error/108760 "2024-01-14T20:37:04Z")

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Hi, I’m new to Julia. I can’t follow what’s going wrong here. When I run the following code in REPL, it is able to run and create a chain of convolution layers: A = Chain(\[Flux.Conv((3,3), 1=\>3, stride=1, pad=2, bias=f…

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## [Dictionary of dictionaries as decision tree](https://discourse.julialang.org/t/dictionary-of-dictionaries-as-decision-tree/108783)

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**Author:** [@leoflotor](https://discourse.julialang.org/u/leoflotor)\
**Replies:** 3\
**Last updated:** [January 14, 2024, 5:33pm UTC](https://discourse.julialang.org/t/dictionary-of-dictionaries-as-decision-tree/108783 "2024-01-14T17:33:22Z")

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Hi! I am trying to do a decision tree using my implementation of ID3 but I am having some problems with one of my functions. For example, I have the following data frame: julia\> df 14×6 DataFrame Row │ pa as …

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## [New registered package VKcurve](https://discourse.julialang.org/t/new-registered-package-vkcurve/108796)

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**Author:** [@Jean\_Michel](https://discourse.julialang.org/u/Jean_Michel)\
**Replies:** 0\
**Last updated:** [January 14, 2024, 5:18pm UTC](https://discourse.julialang.org/t/new-registered-package-vkcurve/108796 "2024-01-14T17:18:18Z")

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This is to announce the package VKcurve which is a port to Julia of the GAP3 package VKcurve written by David Bessis and Jean Michel in 2002. The main function computes the fundamental group of the complement of a c…

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## [What is the best practice for parallel dictionary comprehensions?](https://discourse.julialang.org/t/what-is-the-best-practice-for-parallel-dictionary-comprehensions/108786)

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**Author:** [@cdawg](https://discourse.julialang.org/u/cdawg)\
**Replies:** 3\
**Last updated:** [January 14, 2024, 12:51pm UTC](https://discourse.julialang.org/t/what-is-the-best-practice-for-parallel-dictionary-comprehensions/108786 "2024-01-14T12:51:14Z")

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I’m trying to work out a good template for the parallel part of my experiments. I’m looking for rock-solid example code to copy and and extend based on the current ecosystem. Usually, I’m in the embarrassingly || space…

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## [Instruction sequence for function calls](https://discourse.julialang.org/t/instruction-sequence-for-function-calls/108789)

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**Author:** [@Dichloromethane](https://discourse.julialang.org/u/Dichloromethane)\
**Replies:** 0\
**Last updated:** [January 14, 2024, 11:17am UTC](https://discourse.julialang.org/t/instruction-sequence-for-function-calls/108789 "2024-01-14T11:17:56Z")

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I was looking at some of the code generated by the compiler recently, and saw that, for some reason, the instruction sequence generated for function calls always consists of movabs rax, offset j\_func\_n call rax instead…

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## [Plot sol of differentialequation](https://discourse.julialang.org/t/plot-sol-of-differentialequation/108768)

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**Author:** [@Stephen](https://discourse.julialang.org/u/Stephen)\
**Replies:** 3\
**Last updated:** [January 14, 2024, 4:58am UTC](https://discourse.julialang.org/t/plot-sol-of-differentialequation/108768 "2024-01-14T04:58:34Z")

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using Plots, DifferentialEquations function projectile\_motion(v₀, θ) g = 9.8067 # acceleration due to gravity (m/s^2) t\_final = 2 \* v₀ \* sind(θ) / g # total flight time # Define the system of second-or…

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## [Julia is slower than matlab when it comes to matrix diagonalization?](https://discourse.julialang.org/t/julia-is-slower-than-matlab-when-it-comes-to-matrix-diagonalization/108658)

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**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 39\
**Last updated:** [January 14, 2024, 1:50am UTC](https://discourse.julialang.org/t/julia-is-slower-than-matlab-when-it-comes-to-matrix-diagonalization/108658 "2024-01-14T01:50:08Z")

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The following julia script is a literal translation of the original matlab code, using LinearAlgebra, SparseArrays using Arpack, Plots function bhm\_basis(N, M, dim, weight) basis = zeros(UInt8, M, dim) basis\[1,…

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## [Sparse Spike Deconvolution: how to perform a cross validation using JuMP?](https://discourse.julialang.org/t/sparse-spike-deconvolution-how-to-perform-a-cross-validation-using-jump/108776)

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**Author:** [@Matheus](https://discourse.julialang.org/u/Matheus)\
**Replies:** 4\
**Last updated:** [January 13, 2024, 11:38pm UTC](https://discourse.julialang.org/t/sparse-spike-deconvolution-how-to-perform-a-cross-validation-using-jump/108776 "2024-01-13T23:38:59Z")

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I’m basically trying to minimize the following matrix equation Z(the data) and c are vectors while G and A are matrices. G is a matrix that receives a scalar parameter P. To create the model, I’ve set a fix P and tri…

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## [\[ANN\] SatelliteAnalysis.jl v0.3.0](https://discourse.julialang.org/t/ann-satelliteanalysis-jl-v0-3-0/108781)

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**Author:** [@Ronis\_BR](https://discourse.julialang.org/u/Ronis_BR)\
**Replies:** 0\
**Last updated:** [January 13, 2024, 10:54pm UTC](https://discourse.julialang.org/t/ann-satelliteanalysis-jl-v0-3-0/108781 "2024-01-13T22:54:44Z")

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Hi! After a massive rewrite of the SatelliteToolbox.jl package, I finally managed to finish the first version of SatelliteAnalysis.jl after the revamp! The idea was to split the original huge SatelliteToolbox.jl packag…

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## [Having installed several versions of Julia on machine. How to open a specific version of julia from PowerShell?](https://discourse.julialang.org/t/having-installed-several-versions-of-julia-on-machine-how-to-open-a-specific-version-of-julia-from-powershell/78134)

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**Author:** [@Amro](https://discourse.julialang.org/u/Amro)\
**Replies:** 13\
**Last updated:** [January 13, 2024, 6:11pm UTC](https://discourse.julialang.org/t/having-installed-several-versions-of-julia-on-machine-how-to-open-a-specific-version-of-julia-from-powershell/78134 "2024-01-13T18:11:46Z")

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I have two versions of Julia installed on my machine 1.6.3 and 1.8.0-beta 1. When I write julia in the PowerShell, it opens 1.6.3, how can I select the demanded version? I tried something like below, but it didn’t work C…

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## [@btime inside function](https://discourse.julialang.org/t/btime-inside-function/108773)

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**Author:** [@scheinerman](https://discourse.julialang.org/u/scheinerman)\
**Replies:** 2\
**Last updated:** [January 13, 2024, 3:51pm UTC](https://discourse.julialang.org/t/btime-inside-function/108773 "2024-01-13T15:51:03Z")

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I would like to create a function to time test various operations, but it seems that invoking @btime (from BenchmarkTools) doesn’t work in this situation. Is there a way to use @btime inside a function. (Note: @time work…

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## [Warning against Unicode confusables](https://discourse.julialang.org/t/warning-against-unicode-confusables/108734)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 50\
**Last updated:** [January 13, 2024, 2:27pm UTC](https://discourse.julialang.org/t/warning-against-unicode-confusables/108734 "2024-01-13T14:27:42Z")

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Even in the internal code (the guts; which you might have to look at, coding is not just about APIs), it is possible to have fun with Unicodes: Happy hacking!

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## [Anaconda interfering with vscode](https://discourse.julialang.org/t/anaconda-interfering-with-vscode/108764)

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**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 3\
**Last updated:** [January 13, 2024, 1:55pm UTC](https://discourse.julialang.org/t/anaconda-interfering-with-vscode/108764 "2024-01-13T13:55:59Z")

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I have both vscode and anaconda on my windows desktop. Both can be used to run julia and python. Each time I start vscode and try to run a julia script, I get the error: \[ Info: Precompiling VSCodeServer \[9f5989ce-84fe…

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## [Filter = Returns(false)](https://discourse.julialang.org/t/filter-returns-false/108758)

<div class="topic-metadata">

**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 3\
**Last updated:** [January 13, 2024, 12:46pm UTC](https://discourse.julialang.org/t/filter-returns-false/108758 "2024-01-13T12:46:28Z")

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This is used as a default keyword argument in some function. What does it mean? What does ‘Returns()’ mean? Is it a function?

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## [How to enter unicode letter with hat?](https://discourse.julialang.org/t/how-to-enter-unicode-letter-with-hat/108766)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 1\
**Last updated:** [January 13, 2024, 10:28am UTC](https://discourse.julialang.org/t/how-to-enter-unicode-letter-with-hat/108766 "2024-01-13T10:28:58Z")

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How can I enter this character \\hat U using Unicode?

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## [Issue with Differential Equation Solver](https://discourse.julialang.org/t/issue-with-differential-equation-solver/105008)

<div class="topic-metadata">

**Author:** [@A\_09](https://discourse.julialang.org/u/A_09)\
**Replies:** 35\
**Last updated:** [January 13, 2024, 10:51am UTC](https://discourse.julialang.org/t/issue-with-differential-equation-solver/105008 "2024-01-13T10:51:43Z")

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For this code: begin Parameters, variables, and derivatives @parameters t x @variables T(..) Dt = Differential(t) Dx = Differential(x) Dxx = Differential(x)^2 MOL Discretization parameters x\_max = L x\_min = 0 nc …

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## [How to plot a cube in 3D in Plots.jl](https://discourse.julialang.org/t/how-to-plot-a-cube-in-3d-in-plots-jl/86919)

<div class="topic-metadata">

**Author:** [@chelseas](https://discourse.julialang.org/u/chelseas)\
**Replies:** 10\
**Last updated:** [January 13, 2024, 8:56am UTC](https://discourse.julialang.org/t/how-to-plot-a-cube-in-3d-in-plots-jl/86919 "2024-01-13T08:56:32Z")

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I would like to plot a 3D cube in Plots.jl and I have not been able to. I know that there are solutions in Makie but I would like to use the Plots.jl interface because I want to combine this with other things plotted wi…

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## [ChatGPT Friendly Programming Languages](https://discourse.julialang.org/t/chatgpt-friendly-programming-languages/107220)

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**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 6\
**Last updated:** [January 13, 2024, 6:25am UTC](https://discourse.julialang.org/t/chatgpt-friendly-programming-languages/107220 "2024-01-13T06:25:10Z")

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Article by Doug Eadline on a paper which discusses Chat GPT generated code. "ChatGTP performs the best on Julia, with 81.5% of generated code being successfully executed, and performs the worst on C++, with only 7.3% of…

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