# Latest

**URL:** https://discourse.julialang.org/latest.md?page=535

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

**Page:** 536

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## [Providing initial values in init\_params for compositional sampling](https://discourse.julialang.org/t/providing-initial-values-in-init-params-for-compositional-sampling/107348)

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**Author:** [@ph-rast](https://discourse.julialang.org/u/ph-rast)\
**Replies:** 0\
**Last updated:** [December 8, 2023, 9:47pm UTC](https://discourse.julialang.org/t/providing-initial-values-in-init-params-for-compositional-sampling/107348 "2023-12-08T21:47:00Z")

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Hi there, when I’m passing initial values init\_vals = \[A, init\_beta, init\_eta, init\_sigma, init\_z\] to the init\_params argumenet in sampling() everything works as expected: chain = sample(model, HMC(), MCMCThreads, ... …

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## [MATLAB-like \`unique\` where you can recreate the original with indices](https://discourse.julialang.org/t/matlab-like-unique-where-you-can-recreate-the-original-with-indices/77968)

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**Author:** [@iamed2](https://discourse.julialang.org/u/iamed2)\
**Replies:** 8\
**Last updated:** [December 8, 2023, 8:05pm UTC](https://discourse.julialang.org/t/matlab-like-unique-where-you-can-recreate-the-original-with-indices/77968 "2023-12-08T20:05:30Z")

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Is there an implementation of the MATLAB 3-output unique in Julia? In particular I’m looking for an efficient way to recreate the original input from the unique elements, like C(ic) in MATLAB. Previous discussions have…

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## [How to convert Vector of Vectors to Matrix](https://discourse.julialang.org/t/how-to-convert-vector-of-vectors-to-matrix/72609)

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**Author:** [@XLVII](https://discourse.julialang.org/u/XLVII)\
**Replies:** 39\
**Last updated:** [December 8, 2023, 7:57pm UTC](https://discourse.julialang.org/t/how-to-convert-vector-of-vectors-to-matrix/72609 "2023-12-08T19:57:34Z")

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I have a vector = \[\[1,0,1\],\[ 0,0,1\]\] I am trying to convert this to → \[ 1 0 1 ; 0 0 1 \] How?

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## [Sort indices based on value](https://discourse.julialang.org/t/sort-indices-based-on-value/107299)

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**Author:** [@putianyi888](https://discourse.julialang.org/u/putianyi888)\
**Replies:** 13\
**Last updated:** [December 8, 2023, 7:28pm UTC](https://discourse.julialang.org/t/sort-indices-based-on-value/107299 "2023-12-08T19:28:46Z")

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Is there an existing method that can get a value -\> index map of a vector? For example, something that works like this: function findalls(A::Vector) d = Dict{eltype(A), Vector{Int}}() for (i,v) in enumerate(A) …

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## [Different \`@code\_llvm\` output on macos and x86](https://discourse.julialang.org/t/different-code-llvm-output-on-macos-and-x86/107338)

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**Author:** [@LaurentPlagne](https://discourse.julialang.org/u/LaurentPlagne)\
**Replies:** 4\
**Last updated:** [December 8, 2023, 7:17pm UTC](https://discourse.julialang.org/t/different-code-llvm-output-on-macos-and-x86/107338 "2023-12-08T19:17:31Z")

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Hi, I wonder about the different outputs I obtain from @code\_llvm with the same Julia version (1.10.rc2) on different architectures (arm vs x86). The following script: f(a,b) = a .+ b f (generic function with 1 method…

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## [How can I view W matrix evaluation times and the W matrices themselves?](https://discourse.julialang.org/t/how-can-i-view-w-matrix-evaluation-times-and-the-w-matrices-themselves/107301)

<div class="topic-metadata">

**Author:** [@novalex98](https://discourse.julialang.org/u/novalex98)\
**Replies:** 1\
**Last updated:** [December 8, 2023, 7:16pm UTC](https://discourse.julialang.org/t/how-can-i-view-w-matrix-evaluation-times-and-the-w-matrices-themselves/107301 "2023-12-08T19:16:24Z")

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I’m trying to solve a stubbornly unstable nonlinear ODE. When I plot the terms of my ODE its fairly obvious what time step things start to go wrong at. As seen in this graph, everything starts to fall apart at z = 35…

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## [Safe to interrupt precompilation?](https://discourse.julialang.org/t/safe-to-interrupt-precompilation/107339)

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**Author:** [@Nathan\_Boyer](https://discourse.julialang.org/u/Nathan_Boyer)\
**Replies:** 2\
**Last updated:** [December 8, 2023, 6:17pm UTC](https://discourse.julialang.org/t/safe-to-interrupt-precompilation/107339 "2023-12-08T18:17:45Z")

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If precompilation starts (e.g. when I load an environment or add a package to an environment), is it safe to interrupt that with Ctrl+c (or some other method), if I know I am going to perform another action which is goin…

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## [Error when trying to add Pluto to Julia (Mac)](https://discourse.julialang.org/t/error-when-trying-to-add-pluto-to-julia-mac/107126)

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**Author:** [@molinq](https://discourse.julialang.org/u/molinq)\
**Replies:** 23\
**Last updated:** [December 8, 2023, 5:22pm UTC](https://discourse.julialang.org/t/error-when-trying-to-add-pluto-to-julia-mac/107126 "2023-12-08T17:22:59Z")

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Hey guys, I have just downloaded Julia 1.9 on my MacBook and everytime I try to add Pluto to Julia, I get this error message: (@v1.9) pkg\> dyld: Library not loaded: @rpath/libLLVM.dylib Referenced from: /Applications/…

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## [Performance of lu(A)\\B versus inv(A)\*B to solve AX=B](https://discourse.julialang.org/t/performance-of-lu-a-b-versus-inv-a-b-to-solve-ax-b/107331)

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**Author:** [@Pablo\_Marchant](https://discourse.julialang.org/u/Pablo_Marchant)\
**Replies:** 3\
**Last updated:** [December 8, 2023, 4:48pm UTC](https://discourse.julialang.org/t/performance-of-lu-a-b-versus-inv-a-b-to-solve-ax-b/107331 "2023-12-08T16:48:56Z")

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Hi all, I’m working in a problem where I need to solve various Ax=b systems, where A is a dense (but usually not that large) matrix. Initially I was doing this by directly computing inverses and multiplying. Awful to do…

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## [Plots.jl | Heatmap legend is cut off or lays on top of the colorbar ticks](https://discourse.julialang.org/t/plots-jl-heatmap-legend-is-cut-off-or-lays-on-top-of-the-colorbar-ticks/107329)

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**Author:** [@lenardj](https://discourse.julialang.org/u/lenardj)\
**Replies:** 1\
**Last updated:** [December 8, 2023, 4:44pm UTC](https://discourse.julialang.org/t/plots-jl-heatmap-legend-is-cut-off-or-lays-on-top-of-the-colorbar-ticks/107329 "2023-12-08T16:44:27Z")

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I am using the heatmap function in Plots.jl to plot densities in a plane. The colorbar should have a legend with an explanation “…”. I use the following code: Heatmap = heatmap!(x,y,HeatmapData, c = :thermal,xlabel = “…

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## [Looping over a thousand files and checking if empty](https://discourse.julialang.org/t/looping-over-a-thousand-files-and-checking-if-empty/107291)

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**Author:** [@Balinus](https://discourse.julialang.org/u/Balinus)\
**Replies:** 15\
**Last updated:** [December 8, 2023, 4:39pm UTC](https://discourse.julialang.org/t/looping-over-a-thousand-files-and-checking-if-empty/107291 "2023-12-08T16:39:31Z")

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Hello! I have some results of an experiment. They are stored inside a folder and I need to open the files, check what is the fraction of missing values inside a file and tag it according to different level of missing va…

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## [\[ANN\] FiniteHorizonGramians.jl](https://discourse.julialang.org/t/ann-finitehorizongramians-jl/107325)

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**Author:** [@filtron](https://discourse.julialang.org/u/filtron)\
**Replies:** 0\
**Last updated:** [December 8, 2023, 12:50pm UTC](https://discourse.julialang.org/t/ann-finitehorizongramians-jl/107325 "2023-12-08T12:50:02Z")

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I’m pleased to announce FiniteHorizonGramians.jl. Given a pair of matrices (A, B), this package implements an algorithm for computing both the matrix exonential e^{A t}, and the finite horizon controllability Gramian ove…

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## [Haigh-Westergaard coordinates / π-plane plots](https://discourse.julialang.org/t/haigh-westergaard-coordinates-plane-plots/107335)

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**Author:** [@Gravlax](https://discourse.julialang.org/u/Gravlax)\
**Replies:** 0\
**Last updated:** [December 8, 2023, 3:45pm UTC](https://discourse.julialang.org/t/haigh-westergaard-coordinates-plane-plots/107335 "2023-12-08T15:45:21Z")

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Hi, Does anyone have experience with this type of visualisation? Is there a package that supports this type of diagram? cheers and thanks!

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## [Update on the JuliaCon Proceedings for 2023-24](https://discourse.julialang.org/t/update-on-the-juliacon-proceedings-for-2023-24/103411)

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**Author:** [@ranjan](https://discourse.julialang.org/u/ranjan)\
**Replies:** 3\
**Last updated:** [December 8, 2023, 3:53pm UTC](https://discourse.julialang.org/t/update-on-the-juliacon-proceedings-for-2023-24/103411 "2023-12-08T15:53:52Z")

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Hello, Here are some updates on the JuliaCon Proceedings: The editorial team has been refreshed and we will continue reviewing all of your submissions (as of this notice), including our backlog. The technical infr…

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## [How to release lock on Arrow table](https://discourse.julialang.org/t/how-to-release-lock-on-arrow-table/107046)

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**Author:** [@taotree](https://discourse.julialang.org/u/taotree)\
**Replies:** 7\
**Last updated:** [December 8, 2023, 2:23pm UTC](https://discourse.julialang.org/t/how-to-release-lock-on-arrow-table/107046 "2023-12-08T14:23:01Z")

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I need to read in an Arrow file, combine some data, and then overwrite that file. That means I need to release the file lock that happens when you read. How can I guarantee to release that lock? I’ve read that clearing o…

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## [System image with PyPlot.jl](https://discourse.julialang.org/t/system-image-with-pyplot-jl/107320)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 4\
**Last updated:** [December 8, 2023, 12:00pm UTC](https://discourse.julialang.org/t/system-image-with-pyplot-jl/107320 "2023-12-08T12:00:06Z")

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I created a small project, see: GitHub - ufechner7/Tethers.jl: Tether models For now the code is trivial, but to avoid high time-to-first plot I created a custom system image with ModelingToolkit, OrdinaryDiffEq, and P…

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## [Any way to multiple dispatch on functions?\`](https://discourse.julialang.org/t/any-way-to-multiple-dispatch-on-functions/107318)

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**Author:** [@Jad\_Zeitouni](https://discourse.julialang.org/u/Jad_Zeitouni)\
**Replies:** 7\
**Last updated:** [December 8, 2023, 9:50am UTC](https://discourse.julialang.org/t/any-way-to-multiple-dispatch-on-functions/107318 "2023-12-08T09:50:01Z")

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I defined two abstract types, call them MyType and MyFrozenType{T\<:MyType}. Subtypes SpecificFrozenType \<: MyFrozenStruct{SpecificType} are usually defined as SpecificFrozenType(x::SpecificType, v::Vector) Now, I have …

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## [Parametric types and StaticArrays](https://discourse.julialang.org/t/parametric-types-and-staticarrays/107312)

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**Author:** [@jondavis847](https://discourse.julialang.org/u/jondavis847)\
**Replies:** 2\
**Last updated:** [December 8, 2023, 9:27am UTC](https://discourse.julialang.org/t/parametric-types-and-staticarrays/107312 "2023-12-08T09:27:22Z")

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As I’ve worked through a couple projects now, I realized I don’t fully understand the nuances of parametric types, and specifically when used with StaticArrays. My goal of course is to get all the performance I can, but …

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## [How to create sum-log-likelihood of custom distribution for use in Turing.jl](https://discourse.julialang.org/t/how-to-create-sum-log-likelihood-of-custom-distribution-for-use-in-turing-jl/107011)

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**Author:** [@Bill\_Holmes](https://discourse.julialang.org/u/Bill_Holmes)\
**Replies:** 10\
**Last updated:** [December 8, 2023, 9:19am UTC](https://discourse.julialang.org/t/how-to-create-sum-log-likelihood-of-custom-distribution-for-use-in-turing-jl/107011 "2023-12-08T09:19:16Z")

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I have a seemingly simple question about working with Turing.jl and Distributions.jl I’m hoping someone can help me with. For my work, I need to be able to define custom continuous, uni-variate distributions along with t…

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## [How to preallocate for a parallel monte carlo simulation?](https://discourse.julialang.org/t/how-to-preallocate-for-a-parallel-monte-carlo-simulation/107104)

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**Author:** [@Taneli\_Tolppanen](https://discourse.julialang.org/u/Taneli_Tolppanen)\
**Replies:** 5\
**Last updated:** [December 8, 2023, 8:08am UTC](https://discourse.julialang.org/t/how-to-preallocate-for-a-parallel-monte-carlo-simulation/107104 "2023-12-08T08:08:22Z")

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I am trying to run a series of monte carlo simulations. My simulation gives as an output a matrix. I would like to preallocate this matrix for each of the simulations, and also preallocate some work vectors since I am ru…

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## [Write a table into SQLite and DuckDB in efficient manner](https://discourse.julialang.org/t/write-a-table-into-sqlite-and-duckdb-in-efficient-manner/93417)

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**Author:** [@sairus7](https://discourse.julialang.org/u/sairus7)\
**Replies:** 24\
**Last updated:** [December 8, 2023, 3:25am UTC](https://discourse.julialang.org/t/write-a-table-into-sqlite-and-duckdb-in-efficient-manner/93417 "2023-12-08T03:25:25Z")

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How can I efficiently populate DB table from very long tables (say, millions rows)? I try to compare SQlite vs DuckDB in this scenario, but I think I’m doing this very inefficiently: using SQLite, DuckDB, Tables con\_sq…

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## [Getting Python and conda to work inside Jupyter Notebook in a Julia installation](https://discourse.julialang.org/t/getting-python-and-conda-to-work-inside-jupyter-notebook-in-a-julia-installation/107316)

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**Author:** [@MaxM](https://discourse.julialang.org/u/MaxM)\
**Replies:** 0\
**Last updated:** [December 8, 2023, 5:55am UTC](https://discourse.julialang.org/t/getting-python-and-conda-to-work-inside-jupyter-notebook-in-a-julia-installation/107316 "2023-12-08T05:55:26Z")

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Until yesterday, I had the following setup on my computer. I had Julia 1.9.3 installed. Whenever I wanted to code in Julia or Python I would open the REPL, type using IJulia and notebook(). This would open Jupyter Notebo…

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## [Software references in the code but the ref is ignored by the compiler](https://discourse.julialang.org/t/software-references-in-the-code-but-the-ref-is-ignored-by-the-compiler/107311)

<div class="topic-metadata">

**Author:** [@skypuppy](https://discourse.julialang.org/u/skypuppy)\
**Replies:** 0\
**Last updated:** [December 8, 2023, 3:08am UTC](https://discourse.julialang.org/t/software-references-in-the-code-but-the-ref-is-ignored-by-the-compiler/107311 "2023-12-08T03:08:04Z")

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It occurred to me today, while doing a little a little catch-up of the forum, how convenient it would be to have a reference remark (meta-bookmark?), or pointer to a function, variable, or “unreadable” code embedded righ…

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## [Function name like ‘SMatrix{N,N}’](https://discourse.julialang.org/t/function-name-like-smatrix-n-n/107309)

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**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 1\
**Last updated:** [December 8, 2023, 2:59am UTC](https://discourse.julialang.org/t/function-name-like-smatrix-n-n/107309 "2023-12-08T02:59:32Z")

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The following is a script from here. We see code SA = SMatrix{N,N}(A) Is it ok for a function name to contain the curly brackets? I guess ‘SMatrix{N,N}’ is a function, right? using BenchmarkTools using LinearAlgebra u…

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## [Automatic differentiation for Complex output w.r.t to Real inputs taking too long compared to the function evaluation](https://discourse.julialang.org/t/automatic-differentiation-for-complex-output-w-r-t-to-real-inputs-taking-too-long-compared-to-the-function-evaluation/107288)

<div class="topic-metadata">

**Author:** [@KapilKhanal](https://discourse.julialang.org/u/KapilKhanal)\
**Replies:** 3\
**Last updated:** [December 8, 2023, 1:53am UTC](https://discourse.julialang.org/t/automatic-differentiation-for-complex-output-w-r-t-to-real-inputs-taking-too-long-compared-to-the-function-evaluation/107288 "2023-12-08T01:53:16Z")

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I am using Zygote for differentiating a complex output with respect to 3 real inputs. The function evaluation itself takes about 0.088371 seconds (146.12 k allocations: 10.071 MiB, 99.23% compilation time) but the grad…

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## [Training course "Julia for HPC @ UCL", February 2024](https://discourse.julialang.org/t/training-course-julia-for-hpc-ucl-february-2024/107267)

<div class="topic-metadata">

**Author:** [@giordano](https://discourse.julialang.org/u/giordano)\
**Replies:** 0\
**Last updated:** [December 7, 2023, 11:43am UTC](https://discourse.julialang.org/t/training-course-julia-for-hpc-ucl-february-2024/107267 "2023-12-07T11:43:37Z")

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The UCL Centre for Advanced Research Computing is hosting a 4-day Julia for High-Performance Computing (HPC) training course, from February 13th to February 16th 2024. Starting from the fundamentals of the language, the…

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## [Making sorting a tree represented by vector of any types faster](https://discourse.julialang.org/t/making-sorting-a-tree-represented-by-vector-of-any-types-faster/106998)

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**Author:** [@dgsob](https://discourse.julialang.org/u/dgsob)\
**Replies:** 1\
**Last updated:** [December 7, 2023, 11:04pm UTC](https://discourse.julialang.org/t/making-sorting-a-tree-represented-by-vector-of-any-types-faster/106998 "2023-12-07T23:04:52Z")

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I have an algorithm that generates a tree by multiplying two functions. It works, but my goal is to make it faster. With profiling I’ve found that a substantial amount of time is spend on sorting. I’m wondering if the s…

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## [Turn a module into a package locally](https://discourse.julialang.org/t/turn-a-module-into-a-package-locally/37370)

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**Author:** [@lewis](https://discourse.julialang.org/u/lewis)\
**Replies:** 43\
**Last updated:** [December 7, 2023, 10:35pm UTC](https://discourse.julialang.org/t/turn-a-module-into-a-package-locally/37370 "2023-12-07T22:35:42Z")

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This topic has been asked many times. I have read many posts. Much of the information is incomplete or contradictory. I have read the package manual. It uses the word “project” in 2 very different senses. So, let’s …

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## [Separating the standard libraries from Julia executable](https://discourse.julialang.org/t/separating-the-standard-libraries-from-julia-executable/107208)

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**Author:** [@Impressium](https://discourse.julialang.org/u/Impressium)\
**Replies:** 1\
**Last updated:** [December 6, 2023, 1:36pm UTC](https://discourse.julialang.org/t/separating-the-standard-libraries-from-julia-executable/107208 "2023-12-06T13:36:59Z")

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Hi all :slight\_smile: @jeff.bezanson in your talk at JuliaCon Eindhoven you mentioned that lots of standard libraries should be separate. Here are two options I see. Do 2.0 sooner, non destructive than later take it …

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## [Is there a clean one-liner to subset a vector of vectors?](https://discourse.julialang.org/t/is-there-a-clean-one-liner-to-subset-a-vector-of-vectors/107249)

<div class="topic-metadata">

**Author:** [@Tetrakai](https://discourse.julialang.org/u/Tetrakai)\
**Replies:** 6\
**Last updated:** [December 7, 2023, 8:34pm UTC](https://discourse.julialang.org/t/is-there-a-clean-one-liner-to-subset-a-vector-of-vectors/107249 "2023-12-07T20:34:30Z")

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I have something like this: julia\> A = \[\[1,\[2,3\]\], \[4,\[5,6\]\], \[7,\[8,9\]\]\] 3-element Vector{Vector{Any}}: \[1, \[2, 3\]\] \[4, \[5, 6\]\] \[7, \[8, 9\]\] julia\> B = \[A\[i\]\[2\]\[1\] for i in 1:length(A)\] 3-element Vector{Int64}: 2 5…

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