# Latest

**URL:** https://discourse.julialang.org/latest.md?page=248

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

**Page:** 249

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## [KrylovKit eigsolve of LinearMap giving different values in CPU and GPU](https://discourse.julialang.org/t/krylovkit-eigsolve-of-linearmap-giving-different-values-in-cpu-and-gpu/124032)

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**Author:** [@victor\_vhrn](https://discourse.julialang.org/u/victor_vhrn)\
**Replies:** 7\
**Last updated:** [December 23, 2024, 9:31pm UTC](https://discourse.julialang.org/t/krylovkit-eigsolve-of-linearmap-giving-different-values-in-cpu-and-gpu/124032 "2024-12-23T21:31:07Z")

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I am trying to compare the eigsolve function using CPU and GPU, using the following code: using CUDA using CUDA.CUSPARSE using LinearAlgebra using LinearMaps using SparseArrays using Random using KrylovKit function eig…

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## [\[ANN\] HiddenMarkovModels.jl: when did HMMs get so fast?](https://discourse.julialang.org/t/ann-hiddenmarkovmodels-jl-when-did-hmms-get-so-fast/100191)

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**Author:** [@gdalle](https://discourse.julialang.org/u/gdalle)\
**Replies:** 33\
**Last updated:** [December 23, 2024, 9:29pm UTC](https://discourse.julialang.org/t/ann-hiddenmarkovmodels-jl-when-did-hmms-get-so-fast/100191 "2024-12-23T21:29:51Z")

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What the \*\*\*\* is an HMM? Skip to the good bits below if you’re in a rush Hidden Markov Models (HMMs for short) are a statistical modeling framework that is ubiquitous in signal processing, bioinformatics and plenty …

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## [Weird behavior of lyapynovspectrum from ChaosTools.jl](https://discourse.julialang.org/t/weird-behavior-of-lyapynovspectrum-from-chaostools-jl/124136)

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**Author:** [@EvgenijGr](https://discourse.julialang.org/u/EvgenijGr)\
**Replies:** 3\
**Last updated:** [December 23, 2024, 9:18pm UTC](https://discourse.julialang.org/t/weird-behavior-of-lyapynovspectrum-from-chaostools-jl/124136 "2024-12-23T21:18:12Z")

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Hello! I’ve encountered a weird behavior of lyapunovspectrum when I was investigating my nonlinear system. A MWE can be found here: using ChaosTools, DifferentialEquations, CairoMakie function couple(x, y, vThr, k, hO…

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## [Retain computation results with @btime](https://discourse.julialang.org/t/retain-computation-results-with-btime/62644)

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**Author:** [@jinml](https://discourse.julialang.org/u/jinml)\
**Replies:** 18\
**Last updated:** [December 23, 2024, 8:31pm UTC](https://discourse.julialang.org/t/retain-computation-results-with-btime/62644 "2024-12-23T20:31:30Z")

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I’m trying to time a function and keep its return value: b = @btime y = foo(x) but at the end y is not returned. How can get @btime to also return my result?

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## [Julia book to offer](https://discourse.julialang.org/t/julia-book-to-offer/124140)

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**Author:** [@HugoMVale](https://discourse.julialang.org/u/HugoMVale)\
**Replies:** 0\
**Last updated:** [December 23, 2024, 8:29pm UTC](https://discourse.julialang.org/t/julia-book-to-offer/124140 "2024-12-23T20:29:51Z")

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I would like to give away the following book: Hands-on Design Patterns and Best Practices with Julia The book is excellent and in very good condition. I am happy to send it to a research institute, group, library, or…

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## [\[ANN\] Recamans.jl Recamán's sequence](https://discourse.julialang.org/t/ann-recamans-jl-recamans-sequence/124137)

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**Author:** [@jlapeyre](https://discourse.julialang.org/u/jlapeyre)\
**Replies:** 0\
**Last updated:** [December 23, 2024, 7:52pm UTC](https://discourse.julialang.org/t/ann-recamans-jl-recamans-sequence/124137 "2024-12-23T19:52:06Z")

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The package is here: Recamans.jl Recamán’s sequence a\_0, a\_1, a\_2\\ldots is defined as: a\_n = \\begin{cases} 0 && \\text{if } n = 0 \\\\ a\_{n - 1} -n && \\text{if } a\_{n - 1} -n \> 0 \\text{ and is not already in the sequence…

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## [What causes the performance of this function to tank?](https://discourse.julialang.org/t/what-causes-the-performance-of-this-function-to-tank/124119)

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**Author:** [@world-peace](https://discourse.julialang.org/u/world-peace)\
**Replies:** 5\
**Last updated:** [December 23, 2024, 7:27pm UTC](https://discourse.julialang.org/t/what-causes-the-performance-of-this-function-to-tank/124119 "2024-12-23T19:27:23Z")

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I am doing some work to optimize a slow function call. I have reduced this function down to a simple demonstration example. Here is the “original function”. # alloc: 668.59k, 393.649 MiB function demo( dict::Dict{…

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## [Error with importing matplotlib.pyplot for use with PyCall.jl](https://discourse.julialang.org/t/error-with-importing-matplotlib-pyplot-for-use-with-pycall-jl/124062)

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**Author:** [@ericdammannjr](https://discourse.julialang.org/u/ericdammannjr)\
**Replies:** 5\
**Last updated:** [December 23, 2024, 7:35pm UTC](https://discourse.julialang.org/t/error-with-importing-matplotlib-pyplot-for-use-with-pycall-jl/124062 "2024-12-23T19:35:41Z")

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I am having an issue with PyCall.jl. For context, I am using a Windows PC with a Julia 1.11.2 and Python 3.13.1. I first created a Python virtual environment in the following directory: "C:\\Research Software\\Python\\Virt…

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## [Getting started with the Agents tutorial](https://discourse.julialang.org/t/getting-started-with-the-agents-tutorial/124063)

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**Author:** [@Niall](https://discourse.julialang.org/u/Niall)\
**Replies:** 3\
**Last updated:** [December 23, 2024, 6:55pm UTC](https://discourse.julialang.org/t/getting-started-with-the-agents-tutorial/124063 "2024-12-23T18:55:34Z")

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Hi, I just can’t seem to find out how to the Agents.jl tutorial up and running. I’ve used previous incarnations, but something’s not working this time - it’s been about a year since I last used it. The problems start wi…

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## [Request for comments: Upcoming Kmers.jl version 1.0](https://discourse.julialang.org/t/request-for-comments-upcoming-kmers-jl-version-1-0/108203)

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**Author:** [@jakobnissen](https://discourse.julialang.org/u/jakobnissen)\
**Replies:** 4\
**Last updated:** [December 23, 2024, 6:38pm UTC](https://discourse.julialang.org/t/request-for-comments-upcoming-kmers-jl-version-1-0/108203 "2024-12-23T18:38:07Z")

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Dear BioJulia users and stakeholders, I’m pleased to announce a preview of the first stable release of Kmers.jl, namely version 1.0. The release is essentially done and just needs some more testing and polishing, but b…

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## [Is there a way to find right-inverse (or left-inverse) of a matrix in Julia?](https://discourse.julialang.org/t/is-there-a-way-to-find-right-inverse-or-left-inverse-of-a-matrix-in-julia/124100)

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**Author:** [@shubh\_b](https://discourse.julialang.org/u/shubh_b)\
**Replies:** 10\
**Last updated:** [December 23, 2024, 6:23pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-find-right-inverse-or-left-inverse-of-a-matrix-in-julia/124100 "2024-12-23T18:23:41Z")

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Here is the matrix A julia\> A = \[1 2 3; 0 1 2\] 2×3 Matrix{Int64}: 1 2 3 0 1 2 Matrix A has full row-rank julia\> size(A, 1) == rank(A) true and it has a right-inverse. Can we find the right-inverse of this matri…

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## [Why does not G\\\_N\[TAB\] render Unicode for Newton's constant?](https://discourse.julialang.org/t/why-does-not-g-n-tab-render-unicode-for-newtons-constant/124130)

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**Author:** [@mocalvao](https://discourse.julialang.org/u/mocalvao)\
**Replies:** 1\
**Last updated:** [December 23, 2024, 6:16pm UTC](https://discourse.julialang.org/t/why-does-not-g-n-tab-render-unicode-for-newtons-constant/124130 "2024-12-23T18:16:38Z")

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Hi I know how to type several Unicode characters for my user-defined variable names (i.e. x\_1\[TAB\] for subscripted x indexed by 1), but I would like to know why it is not possible to type, in the REPL, G\_N\[tab\] for Newt…

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## [Global constants](https://discourse.julialang.org/t/global-constants/124105)

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**Author:** [@langestefan](https://discourse.julialang.org/u/langestefan)\
**Replies:** 6\
**Last updated:** [December 23, 2024, 6:14pm UTC](https://discourse.julialang.org/t/global-constants/124105 "2024-12-23T18:14:40Z")

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What is the best (readable, performant) way to store global constants? For example I want to store the Boltzmann constant in a central place and then use it across my package. The compiler would be able to fill this in…

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## [Developing an R package using Julia for a statistical model](https://discourse.julialang.org/t/developing-an-r-package-using-julia-for-a-statistical-model/121320)

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**Author:** [@Mateus\_Maia](https://discourse.julialang.org/u/Mateus_Maia)\
**Replies:** 21\
**Last updated:** [December 23, 2024, 3:35pm UTC](https://discourse.julialang.org/t/developing-an-r-package-using-julia-for-a-statistical-model/121320 "2024-12-23T15:35:42Z")

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Hi all, I would like to know what is the current state of using Julia as a backend for an R package. I writing a code for a statistical model, but I aware that most of the people will use R to run those analysis so I wo…

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## [JuliaCon 2025: Call for Proposals open!](https://discourse.julialang.org/t/juliacon-2025-call-for-proposals-open/124120)

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**Author:** [@ranjan](https://discourse.julialang.org/u/ranjan)\
**Replies:** 0\
**Last updated:** [December 23, 2024, 2:50pm UTC](https://discourse.julialang.org/t/juliacon-2025-call-for-proposals-open/124120 "2024-12-23T14:50:35Z")

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Hello all, We are pleased to open the Call for Proposals for the main tracks of JuliaCon 2025. Please note that this year, participants have the option of submitting a talk directly to a minisymposium, if a minisympo…

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## [ODESystem not handeling dynamic parameters](https://discourse.julialang.org/t/odesystem-not-handeling-dynamic-parameters/124118)

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**Author:** [@Sushrut\_Deshpande](https://discourse.julialang.org/u/Sushrut_Deshpande)\
**Replies:** 0\
**Last updated:** [December 23, 2024, 12:11pm UTC](https://discourse.julialang.org/t/odesystem-not-handeling-dynamic-parameters/124118 "2024-12-23T12:11:06Z")

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Hello, I have a toy problem where I have a parameter that depends on time using ModelingToolkit, DifferentialEquations using ModelingToolkit: t\_nounits as t, D\_nounits as D function test(;name) vars = @variables b…

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## [Issue occurring randomly with 1.11](https://discourse.julialang.org/t/issue-occurring-randomly-with-1-11/121233)

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**Author:** [@ffevotte](https://discourse.julialang.org/u/ffevotte)\
**Replies:** 8\
**Last updated:** [December 23, 2024, 9:51am UTC](https://discourse.julialang.org/t/issue-occurring-randomly-with-1-11/121233 "2024-12-23T09:51:42Z")

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When switching to julia 1.11 in a big project with lots of dependencies, I’ve encountered a strange issue that didn’t happen with 1.10. After some debugging, I’ve managed to isolate the following small reproducible exam…

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## [Type problem running old julia codes](https://discourse.julialang.org/t/type-problem-running-old-julia-codes/123993)

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**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 22\
**Last updated:** [December 23, 2024, 9:26am UTC](https://discourse.julialang.org/t/type-problem-running-old-julia-codes/123993 "2024-12-23T09:26:43Z")

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In running some old julia code (version 0.6.0), I encountered some error: LoadError: UndefVarError: \`T\` not defined The error comes from this line of code: function ph\_conjugate{T}(psi::Vector{T}, states::HaldaneSpher…

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## [Help using CUDA, Zygote, and random numbers](https://discourse.julialang.org/t/help-using-cuda-zygote-and-random-numbers/123458)

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**Author:** [@bgctw](https://discourse.julialang.org/u/bgctw)\
**Replies:** 4\
**Last updated:** [December 23, 2024, 8:59am UTC](https://discourse.julialang.org/t/help-using-cuda-zygote-and-random-numbers/123458 "2024-12-23T08:59:15Z")

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I get the error “llvmcall requires the compiler” when trying to take the gradient of a function that involves generating random numbers in CUDA. Here is a minimal example: using GPUArraysCore: GPUArraysCore using CUDA, …

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## [Errors Using PythonCall.jl and PythonPlot.jl with a Python Virtual Environment](https://discourse.julialang.org/t/errors-using-pythoncall-jl-and-pythonplot-jl-with-a-python-virtual-environment/124084)

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**Author:** [@ericdammannjr](https://discourse.julialang.org/u/ericdammannjr)\
**Replies:** 2\
**Last updated:** [December 22, 2024, 8:40pm UTC](https://discourse.julialang.org/t/errors-using-pythoncall-jl-and-pythonplot-jl-with-a-python-virtual-environment/124084 "2024-12-22T20:40:02Z")

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I really have been struggling with this issue and not sure what to do. For context, I have a brand-new Windows PC, and I have Julia 1.11.2 and Python 3.13.1 installed on it. I did the following: I created a Python virtu…

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## [Automatic package links](https://discourse.julialang.org/t/automatic-package-links/106275)

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**Author:** [@Mason](https://discourse.julialang.org/u/Mason)\
**Replies:** 19\
**Last updated:** [December 22, 2024, 7:42pm UTC](https://discourse.julialang.org/t/automatic-package-links/106275 "2024-12-22T19:42:34Z")

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In the Julia Zulip server, we have something called “linkifiers” which basically just use a regex to detect specific patterns in text, and turn them into links automatically. The main thing we use this for is to turn str…

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## [Why my package work locally but not with \]add](https://discourse.julialang.org/t/why-my-package-work-locally-but-not-with-add/124099)

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**Author:** [@fdekerme](https://discourse.julialang.org/u/fdekerme)\
**Replies:** 1\
**Last updated:** [December 22, 2024, 6:20pm UTC](https://discourse.julialang.org/t/why-my-package-work-locally-but-not-with-add/124099 "2024-12-22T18:20:51Z")

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Hello :smiley:. I published few month ago my first small package DICOMTree.jl, which dispatches the Tree function of Term.jl for medical DICOM data. When I run the package locally on my machine (git fork, cd DICOMtree,…

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## [Syntactic sugar for this pattern?](https://discourse.julialang.org/t/syntactic-sugar-for-this-pattern/124096)

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**Author:** [@linwaytin](https://discourse.julialang.org/u/linwaytin)\
**Replies:** 2\
**Last updated:** [December 22, 2024, 5:35pm UTC](https://discourse.julialang.org/t/syntactic-sugar-for-this-pattern/124096 "2024-12-22T17:35:59Z")

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Sorry for the vague title, but I don’t even know how to describe it in a few words. The following pseudo code describes the problem. new\_res = some\_fn() res = some\_condition(res, new\_res) ? new\_res : res In short, I ne…

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## [Invalid memory operation in delete\_object in HDF5](https://discourse.julialang.org/t/invalid-memory-operation-in-delete-object-in-hdf5/124093)

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**Author:** [@0samuraiE](https://discourse.julialang.org/u/0samuraiE)\
**Replies:** 4\
**Last updated:** [December 22, 2024, 4:45pm UTC](https://discourse.julialang.org/t/invalid-memory-operation-in-delete-object-in-hdf5/124093 "2024-12-22T16:45:52Z")

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Hi. As title suggests, my application crashes occasionally when call delete\_object. Every time I try, the error message changes. Sometimes free(): invalid pointer malloc(): unaligned tcache chunk detected Aborted (core…

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## [Small formatting issue in section 6.3 of manual (pdf specific)](https://discourse.julialang.org/t/small-formatting-issue-in-section-6-3-of-manual-pdf-specific/124094)

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**Author:** [@kern3020](https://discourse.julialang.org/u/kern3020)\
**Replies:** 1\
**Last updated:** [December 22, 2024, 3:09pm UTC](https://discourse.julialang.org/t/small-formatting-issue-in-section-6-3-of-manual-pdf-specific/124094 "2024-12-22T15:09:54Z")

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Hello, I am reading through the pdf version Manual for Julia 1.11.2 and noticed a small formatting issue. If one goes to section 6.3 “Bitwise operators” and looks at the table here, the symbol for two operators are mis…

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## [Gurobi Error 10005: Unable to retrieve attribute 'Pi'](https://discourse.julialang.org/t/gurobi-error-10005-unable-to-retrieve-attribute-pi/53691)

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**Author:** [@rezabayani](https://discourse.julialang.org/u/rezabayani)\
**Replies:** 8\
**Last updated:** [December 22, 2024, 10:08am UTC](https://discourse.julialang.org/t/gurobi-error-10005-unable-to-retrieve-attribute-pi/53691 "2024-12-22T10:08:55Z")

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I am trying to retrieve some Gurobi attributes for through MOI.get() function with direct\_model() enabled. Everything seems to be working but when I try to get “Pi” (dual value for a constraint), I encounter the error: G…

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## [CUDA.jl is slowed down after some number of iterations](https://discourse.julialang.org/t/cuda-jl-is-slowed-down-after-some-number-of-iterations/123911)

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**Author:** [@Alex90](https://discourse.julialang.org/u/Alex90)\
**Replies:** 9\
**Last updated:** [December 22, 2024, 8:27am UTC](https://discourse.julialang.org/t/cuda-jl-is-slowed-down-after-some-number-of-iterations/123911 "2024-12-22T08:27:59Z")

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Hello! When looping simple math operations it was found that CUDA.jl is slowed down after some number of iterations. In this case, most of the execution time is consumed by CuLaunchKernel procedure. I thought that a cus…

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## [How to concatenate two (file) streams](https://discourse.julialang.org/t/how-to-concatenate-two-file-streams/124082)

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**Author:** [@Abhro](https://discourse.julialang.org/u/Abhro)\
**Replies:** 1\
**Last updated:** [December 22, 2024, 6:37am UTC](https://discourse.julialang.org/t/how-to-concatenate-two-file-streams/124082 "2024-12-22T06:37:34Z")

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How to create a stream which sequentially reads from multiple other streams? This is analogous to cat in unix, but for arbitrary streams. In python, something like this might be implemented as: def cat\_streams(s1, s2): …

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## [In Set, what's decompose?](https://discourse.julialang.org/t/in-set-whats-decompose/124031)

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**Author:** [@phma](https://discourse.julialang.org/u/phma)\
**Replies:** 4\
**Last updated:** [December 22, 2024, 6:26am UTC](https://discourse.julialang.org/t/in-set-whats-decompose/124031 "2024-12-22T06:26:38Z")

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I wrote a function which computes something using a SortedSet of a type I defined, which is a fixed-size SVector with no variable-size fields. I thought that maybe using a Set would make it faster, so I changed SortedSet …

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## [VS Code debugger crashes for "Hello World"](https://discourse.julialang.org/t/vs-code-debugger-crashes-for-hello-world/124078)

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**Author:** [@mcaetano](https://discourse.julialang.org/u/mcaetano)\
**Replies:** 2\
**Last updated:** [December 22, 2024, 12:57am UTC](https://discourse.julialang.org/t/vs-code-debugger-crashes-for-hello-world/124078 "2024-12-22T00:57:35Z")

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Hello, I understand that the Julia debugging experience in VS Code is still under development, but I was never able to get the debugger to work even for the “Hello World” script set as the example on VS Code’s page. Whe…

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