# Latest

**URL:** https://discourse.julialang.org/latest.md?page=177

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

**Page:** 178

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## [Singular Exception with LKJCholesky](https://discourse.julialang.org/t/singular-exception-with-lkjcholesky/85020)

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**Author:** [@joshualeond](https://discourse.julialang.org/u/joshualeond)\
**Replies:** 24\
**Last updated:** [April 25, 2025, 4:41pm UTC](https://discourse.julialang.org/t/singular-exception-with-lkjcholesky/85020 "2025-04-25T16:41:08Z")

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Hi there, I’ve seen the recent development for the LKJCholesky implementations within Distributions.jl and am attempting to put it to use within Turing.jl. I understand that Turing.jl doesn’t yet support Cholesky Variat…

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## [Sub-arrays of static arrays](https://discourse.julialang.org/t/sub-arrays-of-static-arrays/128406)

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**Author:** [@TimHargreaves](https://discourse.julialang.org/u/TimHargreaves)\
**Replies:** 6\
**Last updated:** [April 25, 2025, 5:53pm UTC](https://discourse.julialang.org/t/sub-arrays-of-static-arrays/128406 "2025-04-25T17:53:47Z")

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From a previous step in my computations, I have a static array and I would now like to perform an operation, say a QR decomposition, on a sub-array. This is performance critical code so I would like to squeeze as much sp…

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## [Nextfloat is slower on 2D array than on 1D array](https://discourse.julialang.org/t/nextfloat-is-slower-on-2d-array-than-on-1d-array/128380)

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**Author:** [@hawahe](https://discourse.julialang.org/u/hawahe)\
**Replies:** 14\
**Last updated:** [April 25, 2025, 4:27pm UTC](https://discourse.julialang.org/t/nextfloat-is-slower-on-2d-array-than-on-1d-array/128380 "2025-04-25T16:27:36Z")

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Running the following function with a 2D array is much slower than running it with the same array but flattened to a 1D array, and both return the same result. Why is the 2D version slower? function test(data::Array{Flo…

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## [Why Are Statically Sized Arrays Immutable?](https://discourse.julialang.org/t/why-are-statically-sized-arrays-immutable/128331)

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**Author:** [@cadojo](https://discourse.julialang.org/u/cadojo)\
**Replies:** 30\
**Last updated:** [April 25, 2025, 3:06pm UTC](https://discourse.julialang.org/t/why-are-statically-sized-arrays-immutable/128331 "2025-04-25T15:06:20Z")

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I often hear that StaticArrays.SArray is immutable because it is stack allocated. I’m sure this is a misunderstanding on my end, though, because stack allocated types in other languages can be mutated in other languages. …

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## [Using Catalyst ODEproblem and algebraic equations](https://discourse.julialang.org/t/using-catalyst-odeproblem-and-algebraic-equations/128375)

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**Author:** [@AnthonySoive](https://discourse.julialang.org/u/AnthonySoive)\
**Replies:** 4\
**Last updated:** [April 25, 2025, 12:50pm UTC](https://discourse.julialang.org/t/using-catalyst-odeproblem-and-algebraic-equations/128375 "2025-04-25T12:50:33Z")

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Dear all, I am trying to add algebraic equations to a Catalyst reaction system. I read old post on this subject where It was not possible to do with ODEproblem function. Is it still the case? For example, I’ve tried thi…

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## [Could \`svd!\` support option \`check=false\` like \`lu!\` and other factorizations?](https://discourse.julialang.org/t/could-svd-support-option-check-false-like-lu-and-other-factorizations/128386)

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**Author:** [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Replies:** 5\
**Last updated:** [April 25, 2025, 12:17pm UTC](https://discourse.julialang.org/t/could-svd-support-option-check-false-like-lu-and-other-factorizations/128386 "2025-04-25T12:17:38Z")

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The check=false option present in lu!, bunchkaufman! and other factorization routines is super useful to handle exceptions efficiently. Unfortunately, the svd! doesn’t have this option and I am getting LinearAlgebra.LAPA…

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## [\[ANN\] Spectra.jl: new major release!](https://discourse.julialang.org/t/ann-spectra-jl-new-major-release/128396)

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**Author:** [@charlesll](https://discourse.julialang.org/u/charlesll)\
**Replies:** 0\
**Last updated:** [April 25, 2025, 11:40am UTC](https://discourse.julialang.org/t/ann-spectra-jl-new-major-release/128396 "2025-04-25T11:40:48Z")

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Spectra.jl version 2.0.1 is just out! Spectra.jl is a package aimed at helping spectroscopic (Raman, Infrared, Nuclear Magnetic Resonance, XAS…) data treatment under Julia. The aim is to provide a simplest way to perfor…

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## [Violin plot](https://discourse.julialang.org/t/violin-plot/128381)

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**Author:** [@miguelborrero](https://discourse.julialang.org/u/miguelborrero)\
**Replies:** 8\
**Last updated:** [April 25, 2025, 11:27am UTC](https://discourse.julialang.org/t/violin-plot/128381 "2025-04-25T11:27:17Z")

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Hi there, It seems like violin plots truncate the support of the data. My understanding is that violin plots are kernel density estimates of the data but I’m struggling to find more information about the actual details. …

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## [StackOverflow when passing dictionary to ODE solver?](https://discourse.julialang.org/t/stackoverflow-when-passing-dictionary-to-ode-solver/128363)

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**Author:** [@Theodore\_Rieger](https://discourse.julialang.org/u/Theodore_Rieger)\
**Replies:** 2\
**Last updated:** [April 25, 2025, 11:21am UTC](https://discourse.julialang.org/t/stackoverflow-when-passing-dictionary-to-ode-solver/128363 "2025-04-25T11:21:17Z")

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Hi, I’m getting a stackoverflow error (full error message below) when I try to pass my parameters as a dictionary. Simple example: using DifferentialEquations using Plots using StatsKit function lorenz!(du, u, p, t) …

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## [Initial guess for array-valued variables not passed to NonlinearProblem](https://discourse.julialang.org/t/initial-guess-for-array-valued-variables-not-passed-to-nonlinearproblem/128372)

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**Author:** [@sass-jacob](https://discourse.julialang.org/u/sass-jacob)\
**Replies:** 1\
**Last updated:** [April 25, 2025, 11:07am UTC](https://discourse.julialang.org/t/initial-guess-for-array-valued-variables-not-passed-to-nonlinearproblem/128372 "2025-04-25T11:07:35Z")

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I have created a MWE in which it seems the initial guess for array-valued variables set as irreducible is not passed to NonlinearProblem. Please advise if there is an alternative way to do this or if an issue should be p…

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## [Using operator relative entropy cone in Julia](https://discourse.julialang.org/t/using-operator-relative-entropy-cone-in-julia/128285)

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**Author:** [@zhouhh17](https://discourse.julialang.org/u/zhouhh17)\
**Replies:** 7\
**Last updated:** [April 25, 2025, 11:05am UTC](https://discourse.julialang.org/t/using-operator-relative-entropy-cone-in-julia/128285 "2025-04-25T11:05:37Z")

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Question Is it possible to optimize over the following operator relative entropy cone natively in Julia: \\text{cl}\\{(A, B, C)\\in H^n\_+ \\times H^n\_+ \\times H^n: C \\succeq - A^{1/2} \\log(A^{-1/2} B A^{-1/2}) A^{1/2}\\} w…

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## [Getting a LoadError: GPUCompiler.InvalidIRError on trying to use LuxCUDA with EnsembleProblem](https://discourse.julialang.org/t/getting-a-loaderror-gpucompiler-invalidirerror-on-trying-to-use-luxcuda-with-ensembleproblem/128328)

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**Author:** [@sunaina2821](https://discourse.julialang.org/u/sunaina2821)\
**Replies:** 3\
**Last updated:** [April 25, 2025, 11:02am UTC](https://discourse.julialang.org/t/getting-a-loaderror-gpucompiler-invalidirerror-on-trying-to-use-luxcuda-with-ensembleproblem/128328 "2025-04-25T11:02:16Z")

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Here’s a MWE for my problem. I’ve been trying to use Lux with GPU and have been working on a similar problem as the MWE. The error results from the U(u, p, st)\[1\] line in most cases. At times I get it due to scalar index…

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## [Is it ok to iterate inside a \`@simd\` loop?](https://discourse.julialang.org/t/is-it-ok-to-iterate-inside-a-simd-loop/128338)

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**Author:** [@mbauman](https://discourse.julialang.org/u/mbauman)\
**Replies:** 8\
**Last updated:** [April 25, 2025, 10:29am UTC](https://discourse.julialang.org/t/is-it-ok-to-iterate-inside-a-simd-loop/128338 "2025-04-25T10:29:35Z")

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I’m delightfully surprised that this works: function mr(f, op, A, n) a1, s = iterate(A) a2, s = iterate(A, s) v = op(f(a1), f(a2)) @simd for \_ in 3:n ai, s = iterate(A, s) v = op(v, f(ai)…

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## [Weird error in GitHub action: ERROR: LoadError: KeyError: key "PrecompileTools" not found](https://discourse.julialang.org/t/weird-error-in-github-action-error-loaderror-keyerror-key-precompiletools-not-found/128377)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 7\
**Last updated:** [April 25, 2025, 8:26am UTC](https://discourse.julialang.org/t/weird-error-in-github-action-error-loaderror-keyerror-key-precompiletools-not-found/128377 "2025-04-25T08:26:39Z")

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I m trying to push a newer version of a package on GitHub. It tests fine in local, but on github actions I have the following weird error: Testing DICEModel Status \`/tmp/jl\_AC62Th/Project.toml\` ERROR: LoadEr…

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## [How does Documenter.jl import the parent package?](https://discourse.julialang.org/t/how-does-documenter-jl-import-the-parent-package/128387)

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**Author:** [@co1emi11er](https://discourse.julialang.org/u/co1emi11er)\
**Replies:** 4\
**Last updated:** [April 25, 2025, 6:49am UTC](https://discourse.julialang.org/t/how-does-documenter-jl-import-the-parent-package/128387 "2025-04-25T06:49:44Z")

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I am writing documentation for my package AISCSteel.jl. I am wanting to use my other package Handcalcs.jl to show some of the steps in the documentation. There is one limitation to Handcalcs.jl and that is that it will …

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## [\[ANN\] LibXLSXWriter.jl - Write XLSX files](https://discourse.julialang.org/t/ann-libxlsxwriter-jl-write-xlsx-files/128390)

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**Author:** [@jaakkor2](https://discourse.julialang.org/u/jaakkor2)\
**Replies:** 0\
**Last updated:** [April 25, 2025, 5:43am UTC](https://discourse.julialang.org/t/ann-libxlsxwriter-jl-write-xlsx-files/128390 "2025-04-25T05:43:31Z")

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Happy to announce LibXLSXWriter.jl, a lightweight, feature complete, and fast-loading package to write XLSX (“Excel”) files. This package provides a Julia interface to the libxlsxwriter C library, making it easy and eff…

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## [Best libraries for experimenting with small scale models?](https://discourse.julialang.org/t/best-libraries-for-experimenting-with-small-scale-models/128106)

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**Author:** [@stur86](https://discourse.julialang.org/u/stur86)\
**Replies:** 7\
**Last updated:** [April 25, 2025, 2:38am UTC](https://discourse.julialang.org/t/best-libraries-for-experimenting-with-small-scale-models/128106 "2025-04-25T02:38:27Z")

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I’m looking for tools to do ML experiments in Julia. Specifically, I’d like trying to design some small-ish models (hundreds to thousands of parameters) and experiment with different approaches that aren’t just different…

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## [Pre-allocate intermediate arrays for multi-threading](https://discourse.julialang.org/t/pre-allocate-intermediate-arrays-for-multi-threading/128312)

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**Author:** [@pulk\_jain](https://discourse.julialang.org/u/pulk_jain)\
**Replies:** 12\
**Last updated:** [April 24, 2025, 10:37pm UTC](https://discourse.julialang.org/t/pre-allocate-intermediate-arrays-for-multi-threading/128312 "2025-04-24T22:37:45Z")

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Hi, I need help in pre-allocating some inner-variables of a for loop to reduce allocations in a multi-threaded code. I am creating multiple local arrays inside the for loop for intermediate calculations. Here’s a MWE wit…

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## [@info doesn't show whole vector in task](https://discourse.julialang.org/t/info-doesnt-show-whole-vector-in-task/128385)

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**Author:** [@phma](https://discourse.julialang.org/u/phma)\
**Replies:** 0\
**Last updated:** [April 24, 2025, 7:53pm UTC](https://discourse.julialang.org/t/info-doesnt-show-whole-vector-in-task/128385 "2025-04-24T19:53:33Z")

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I added this @info message to a function which is called from a task: @info "Blending" file=basename(blendFileName) streamNum blend=OffsetArrays.no\_offset\_view(blend) I get this output: ┌ Info: Blending │ file = "gg…

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## [How do I redirect stdin to interactive Julia?](https://discourse.julialang.org/t/how-do-i-redirect-stdin-to-interactive-julia/128322)

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**Author:** [@phma](https://discourse.julialang.org/u/phma)\
**Replies:** 5\
**Last updated:** [April 24, 2025, 7:44pm UTC](https://discourse.julialang.org/t/how-do-i-redirect-stdin-to-interactive-julia/128322 "2025-04-24T19:44:47Z")

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I need to run a Pkg command on several remote boxen. I wrote a file like this: \] dev ../Foo/ ../Bar/ ../Baz/ ../Quux/ and ran julia --project -i \</path/to/file in the project directory. Julia responded: ERROR: ParseEr…

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## [Overloading and performances](https://discourse.julialang.org/t/overloading-and-performances/128342)

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**Author:** [@Gesee](https://discourse.julialang.org/u/Gesee)\
**Replies:** 10\
**Last updated:** [April 24, 2025, 4:12pm UTC](https://discourse.julialang.org/t/overloading-and-performances/128342 "2025-04-24T16:12:10Z")

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Hi, I am trying to make a symbolic system and on my way, I stumbled upon something that I can’t figure out. I created multiple node to construct the syntax but when making a tree with x = SymbNode(:x) tree = AddNode(P…

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## [Getting duals for nonlinear programming problem](https://discourse.julialang.org/t/getting-duals-for-nonlinear-programming-problem/11357)

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**Author:** [@pedroborgesmelo](https://discourse.julialang.org/u/pedroborgesmelo)\
**Replies:** 7\
**Last updated:** [April 24, 2025, 3:55pm UTC](https://discourse.julialang.org/t/getting-duals-for-nonlinear-programming-problem/11357 "2025-04-24T15:55:42Z")

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Hi Guys! I’m having problems getting the dual variables for a nonlinear problem, with Ipopt as the solver… I just found this post here of 2015, but not working here and a bit old: https://github.com/JuliaOpt/JuMP.jl/i…

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## [\]test fails in vscode](https://discourse.julialang.org/t/test-fails-in-vscode/128371)

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**Author:** [@freeman](https://discourse.julialang.org/u/freeman)\
**Replies:** 3\
**Last updated:** [April 24, 2025, 3:34pm UTC](https://discourse.julialang.org/t/test-fails-in-vscode/128371 "2025-04-24T15:34:19Z")

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(MyPkg) pkg\> test Testing MyPkg Status \`/tmp/jl\_SGBb6L/Project.toml\` \[ab5201b8\] MyPkg v1.0.0 \`~/repos/MyPkg.jl\` \[8dfed614\] Test v1.11.0 Status \`/tmp/jl\_SGBb6L/Manifest.toml\` \[ab5201b8\] MyPkg v1.0.0…

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## [Disable default tooltip in Pluto](https://discourse.julialang.org/t/disable-default-tooltip-in-pluto/128307)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 5\
**Last updated:** [April 24, 2025, 12:26pm UTC](https://discourse.julialang.org/t/disable-default-tooltip-in-pluto/128307 "2025-04-24T12:26:48Z")

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Hi, I am using @NTBond in PlutoExtras.jl to make a widget. Here is a basic example from the documentation: @NTBond "WoW" begin a = ("Description", Slider(1:10)) end I injected custom code into the tuple where “Descri…

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## [Getting GPU info](https://discourse.julialang.org/t/getting-gpu-info/30913)

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**Author:** [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)\
**Replies:** 4\
**Last updated:** [April 24, 2025, 11:41am UTC](https://discourse.julialang.org/t/getting-gpu-info/30913 "2025-04-24T11:41:40Z")

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Hi folks, I’m kinda starting with all this CUDA stuff, and am working with different GPUs on different computers (home, work, etc…). I’m building my first kernels, and one of the things that I need to know is the size o…

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## [Unitful @refunit converts to other length units](https://discourse.julialang.org/t/unitful-refunit-converts-to-other-length-units/128327)

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**Author:** [@prittjam](https://discourse.julialang.org/u/prittjam)\
**Replies:** 1\
**Last updated:** [April 24, 2025, 11:14am UTC](https://discourse.julialang.org/t/unitful-refunit-converts-to-other-length-units/128327 "2025-04-24T11:14:46Z")

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I define a pixel as a reference unit as follows @refunit px "px" Pixel Unitful.𝐋 true However, the following happens despite not defining its size, uconvert(u"mm", 1u"px") 1000 mm Is this expected?

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## [Mac mini M4 pro vs AMD Ryzen 9 9950X for Linear Algebra?](https://discourse.julialang.org/t/mac-mini-m4-pro-vs-amd-ryzen-9-9950x-for-linear-algebra/122029)

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**Author:** [@Norman](https://discourse.julialang.org/u/Norman)\
**Replies:** 56\
**Last updated:** [April 24, 2025, 11:11am UTC](https://discourse.julialang.org/t/mac-mini-m4-pro-vs-amd-ryzen-9-9950x-for-linear-algebra/122029 "2025-04-24T11:11:32Z")

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I hope it doesn’t sound too silly to talk about a product that has just been released but has not come to the market yet. My use case is mostly for doing computation that can be boiled down to some linear problems (poss…

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## [Band-gap structure of Mathieu equation](https://discourse.julialang.org/t/band-gap-structure-of-mathieu-equation/128360)

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**Author:** [@acubed](https://discourse.julialang.org/u/acubed)\
**Replies:** 0\
**Last updated:** [April 24, 2025, 10:25am UTC](https://discourse.julialang.org/t/band-gap-structure-of-mathieu-equation/128360 "2025-04-24T10:25:41Z")

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I want to plot band-gap structure (also called zone structure) for the Mathieu equation, u''(t)+(B+A\\cos t)u(t)=0. According to the Floquet theory, this structure can be obtained by the computation of the monodromy matri…

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## [Continuous callbacks checking on u works on standard ODE version but does not work in the Jump Process](https://discourse.julialang.org/t/continuous-callbacks-checking-on-u-works-on-standard-ode-version-but-does-not-work-in-the-jump-process/127390)

<div class="topic-metadata">

**Author:** [@atiyabzafar](https://discourse.julialang.org/u/atiyabzafar)\
**Replies:** 9\
**Last updated:** [April 24, 2025, 10:17am UTC](https://discourse.julialang.org/t/continuous-callbacks-checking-on-u-works-on-standard-ode-version-but-does-not-work-in-the-jump-process/127390 "2025-04-24T10:17:11Z")

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I am trying to solve a system both deterministically and stochastically. The solutions match for my system in both cases without callback. But the callback does not seem to be working. function condition1(u,t,integrato…

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## [Can Ipopt provide a dual bound?](https://discourse.julialang.org/t/can-ipopt-provide-a-dual-bound/128354)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 2\
**Last updated:** [April 24, 2025, 6:57am UTC](https://discourse.julialang.org/t/can-ipopt-provide-a-dual-bound/128354 "2025-04-24T06:57:46Z")

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Continuing the discussion from Getting duals for nonlinear programming problem: As an extension, I asked ChatGPT this problem. Can anyone tell me where is its idea from? Does its reply make sense?

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