# Latest

**URL:** https://discourse.julialang.org/latest.md?page=580

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

**Page:** 581

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## [On the future of Flux.destructure and SciML integration](https://discourse.julialang.org/t/on-the-future-of-flux-destructure-and-sciml-integration/104760)

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**Author:** [@Bizzi](https://discourse.julialang.org/u/Bizzi)\
**Replies:** 4\
**Last updated:** [October 9, 2023, 8:24pm UTC](https://discourse.julialang.org/t/on-the-future-of-flux-destructure-and-sciml-integration/104760 "2023-10-09T20:24:50Z")

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Due to some technical limitations regarding Lux and coupling layers (1, 2, 3) and the existence of InvertibleNetworks.jl, I have chosen to use Flux for my designs. Still, my long-term objective would be to use Optimizati…

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## [How do tree hashes in registry Versions.toml work?](https://discourse.julialang.org/t/how-do-tree-hashes-in-registry-versions-toml-work/104581)

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**Author:** [@tgf314](https://discourse.julialang.org/u/tgf314)\
**Replies:** 8\
**Last updated:** [October 9, 2023, 6:32pm UTC](https://discourse.julialang.org/t/how-do-tree-hashes-in-registry-versions-toml-work/104581 "2023-10-09T18:32:00Z")

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I’m trying to create a local registry/package mirror and I’m having trouble understanding exactly how the git-tree-sha1 hashes in Versions.toml work. They do not seem to correspond to git commit hashes but instead repre…

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## [Set parameter dependent time steps using OrdinaryDiffEq](https://discourse.julialang.org/t/set-parameter-dependent-time-steps-using-ordinarydiffeq/104759)

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**Author:** [@henry2004y](https://discourse.julialang.org/u/henry2004y)\
**Replies:** 2\
**Last updated:** [October 9, 2023, 6:09pm UTC](https://discourse.julialang.org/t/set-parameter-dependent-time-steps-using-ordinarydiffeq/104759 "2023-10-09T18:09:24Z")

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Hi, I have a question about how to set time-dependent time steps (or maximum time steps) for solving an ODE. For a quick demo, say we are dealing with this simple ODE: using OrdinaryDiffEq f(u, p, t) = 1.01 \* p \* u u0…

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## [JuliaRegistries: can't update my package because of registry dirty](https://discourse.julialang.org/t/juliaregistries-cant-update-my-package-because-of-registry-dirty/89379)

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**Author:** [@leo.boisvert](https://discourse.julialang.org/u/leo.boisvert)\
**Replies:** 9\
**Last updated:** [October 9, 2023, 5:34pm UTC](https://discourse.julialang.org/t/juliaregistries-cant-update-my-package-because-of-registry-dirty/89379 "2023-10-09T17:34:59Z")

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Hi! I just joined a research lab and I’m trying to bring a little structure to the project I’m working on: GitHub - corail-research/SeaPearl.jl: Julia hybrid constraint programming solver enhanced by a reinforcement lea…

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## [Custom Markershapes in Plots jl](https://discourse.julialang.org/t/custom-markershapes-in-plots-jl/104542)

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**Author:** [@Gattu\_Mytraya](https://discourse.julialang.org/u/Gattu_Mytraya)\
**Replies:** 4\
**Last updated:** [October 4, 2023, 2:39pm UTC](https://discourse.julialang.org/t/custom-markershapes-in-plots-jl/104542 "2023-10-04T14:39:27Z")

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I would like to use custom marker shapes (I hope to import them as SVG files) in scatterplots using Plots jl. How can I do this?

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## [Filtering Dataframe date column](https://discourse.julialang.org/t/filtering-dataframe-date-column/104658)

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**Author:** [@rajmac](https://discourse.julialang.org/u/rajmac)\
**Replies:** 8\
**Last updated:** [October 9, 2023, 3:43pm UTC](https://discourse.julialang.org/t/filtering-dataframe-date-column/104658 "2023-10-09T15:43:57Z")

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I have a dataframe formed by reading in a CSV file as df3 = CSV.read(“data//weight\_filtered.csv”, dateformat=“yyyy-mm-dd”. Row │ Date Data │ Date Float32 ─────┼───────────────────── 1 │ 2022-07-01 20…

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## [Why does my Flux model return in all NaN?](https://discourse.julialang.org/t/why-does-my-flux-model-return-in-all-nan/104742)

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**Author:** [@tiZ](https://discourse.julialang.org/u/tiZ)\
**Replies:** 2\
**Last updated:** [October 9, 2023, 6:59am UTC](https://discourse.julialang.org/t/why-does-my-flux-model-return-in-all-nan/104742 "2023-10-09T06:59:38Z")

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Hi friends here, I would like to ask a question about the Flux training, and I am try to understand why my model will return NaN value after a failed training step. for example I have such a model, input shape of it is…

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## [SMatrix{2, 2, Float64} is not a concrete type?](https://discourse.julialang.org/t/smatrix-2-2-float64-is-not-a-concrete-type/104638)

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**Author:** [@bremez](https://discourse.julialang.org/u/bremez)\
**Replies:** 8\
**Last updated:** [October 9, 2023, 2:51pm UTC](https://discourse.julialang.org/t/smatrix-2-2-float64-is-not-a-concrete-type/104638 "2023-10-09T14:51:12Z")

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I’m writing some program which for the sake of aesthetics manipulates data as SMatrix{2,2, Float64}. However, I noticed that, having a collection of such SMatrices, say in variable Ms, the command sum(Ms) allocates memor…

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## [Setting up gurobi environment inside a module](https://discourse.julialang.org/t/setting-up-gurobi-environment-inside-a-module/104736)

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**Author:** [@math\_opt](https://discourse.julialang.org/u/math_opt)\
**Replies:** 8\
**Last updated:** [October 9, 2023, 2:22pm UTC](https://discourse.julialang.org/t/setting-up-gurobi-environment-inside-a-module/104736 "2023-10-09T14:22:52Z")

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I have a module that has some functions that run some optimization problems modeling using the JuMP package and the Gurobi solver. a very generic structure of the code is as follows: module TestModule using JuMP using…

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## [Precompilation Fails on HPC](https://discourse.julialang.org/t/precompilation-fails-on-hpc/104664)

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**Author:** [@aadam](https://discourse.julialang.org/u/aadam)\
**Replies:** 16\
**Last updated:** [October 9, 2023, 1:18pm UTC](https://discourse.julialang.org/t/precompilation-fails-on-hpc/104664 "2023-10-09T13:18:35Z")

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I tried adding IJulia to the base environment first, but it gave the precompilation error where it wasn’t able to precompile Parsers, JSON, Conda, IJulia. I then tried adding CSV and it again fails at the precompilation…

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## [Why does try\\catch not work in this example?](https://discourse.julialang.org/t/why-does-try-catch-not-work-in-this-example/104751)

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**Author:** [@ovt](https://discourse.julialang.org/u/ovt)\
**Replies:** 1\
**Last updated:** [October 9, 2023, 1:17pm UTC](https://discourse.julialang.org/t/why-does-try-catch-not-work-in-this-example/104751 "2023-10-09T13:17:29Z")

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julia\> using PlotlyLight julia\> try Plot(y=\[NaN,NaN\]) catch e @warn "NaN in plot" end Error showing value of type Plot: ERROR: NaN not allowed to be written in JSON spec

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## [HPC Slurm Logging Peer Check](https://discourse.julialang.org/t/hpc-slurm-logging-peer-check/104732)

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**Author:** [@TI36XPro](https://discourse.julialang.org/u/TI36XPro)\
**Replies:** 4\
**Last updated:** [October 9, 2023, 1:05pm UTC](https://discourse.julialang.org/t/hpc-slurm-logging-peer-check/104732 "2023-10-09T13:05:21Z")

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Hello, I am looking for some help understanding what is probably a familiar problem to those who run Julia regularly on an HPC with Slurm. I’ll explain the issue and then share what I’ve found. Hopefully someone can hel…

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## ["show" nested struct](https://discourse.julialang.org/t/show-nested-struct/85298)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 4\
**Last updated:** [October 9, 2023, 11:46am UTC](https://discourse.julialang.org/t/show-nested-struct/85298 "2023-10-09T11:46:13Z")

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How can I use the show method for a type that is nested in another struct? For example: julia\> struct A x::Int end julia\> Base.show(io::IO, ::MIME"text/plain", a::A) = print(io, "\>\>A$(a.x)") julia\> s…

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## [How to scale the density of violin plot](https://discourse.julialang.org/t/how-to-scale-the-density-of-violin-plot/104737)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 2\
**Last updated:** [October 9, 2023, 11:06am UTC](https://discourse.julialang.org/t/how-to-scale-the-density-of-violin-plot/104737 "2023-10-09T11:06:58Z")

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I would like to use a violin plot to display density information. For the x-axis, the scaling matters. However, only the shape of the densities matter. How can I rescale the densities to prevent occlusion? Here is a si…

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## [Scalability and Efficiency of Julia for a Multi-Agent Scheduling System?](https://discourse.julialang.org/t/scalability-and-efficiency-of-julia-for-a-multi-agent-scheduling-system/104320)

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**Author:** [@brunbjerg](https://discourse.julialang.org/u/brunbjerg)\
**Replies:** 13\
**Last updated:** [October 9, 2023, 11:06am UTC](https://discourse.julialang.org/t/scalability-and-efficiency-of-julia-for-a-multi-agent-scheduling-system/104320 "2023-10-09T11:06:08Z")

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I’m working on a Ph.D. project, trying to design a multi-agent scheduling system where I need high performance, scalability and reliability. Initially, I thought about creating a metaheuristic/Matheuristic model to solv…

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## [To convert vector of different dimension-vectors to matrix](https://discourse.julialang.org/t/to-convert-vector-of-different-dimension-vectors-to-matrix/104730)

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**Author:** [@gkeee](https://discourse.julialang.org/u/gkeee)\
**Replies:** 8\
**Last updated:** [October 9, 2023, 10:25am UTC](https://discourse.julialang.org/t/to-convert-vector-of-different-dimension-vectors-to-matrix/104730 "2023-10-09T10:25:05Z")

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a 3-element Vector{Vector{Float64}}: \[1.0\] \[1.0, -1.0\] \[1.0, -2.0, 0.5\] ı want to obtain \[1.0, 0.0, 0.0; 1.0, -1.0, 0.0; 1.0, -2.0, 0.5\] How can ı do?

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## [Unknown memory allocation when displaying pixels in Gtk.jl](https://discourse.julialang.org/t/unknown-memory-allocation-when-displaying-pixels-in-gtk-jl/82566)

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**Author:** [@Alan\_Bahm](https://discourse.julialang.org/u/Alan_Bahm)\
**Replies:** 1\
**Last updated:** [October 9, 2023, 9:47am UTC](https://discourse.julialang.org/t/unknown-memory-allocation-when-displaying-pixels-in-gtk-jl/82566 "2023-10-09T09:47:29Z")

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Hi all! I have some memory allocation I don’t understand when using Gtk, and hoping for some advice. I’ve built an application to display and tweak (many) scientifically computed 2kx2k images, and they are displayed …

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## [Adding network graph edges at each model step](https://discourse.julialang.org/t/adding-network-graph-edges-at-each-model-step/104720)

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**Author:** [@SageAnastasi](https://discourse.julialang.org/u/SageAnastasi)\
**Replies:** 1\
**Last updated:** [October 9, 2023, 9:26am UTC](https://discourse.julialang.org/t/adding-network-graph-edges-at-each-model-step/104720 "2023-10-09T09:26:40Z")

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Hi! I’m working on agent-based modelling of a social network graph. I’ve been basing my first attempt on hacking together the Schelling segregation and schoolyard examples. The model is supposed to check whether each age…

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## [LWFBrook90 simulation questions 2 (plotting and csv saving)](https://discourse.julialang.org/t/lwfbrook90-simulation-questions-2-plotting-and-csv-saving/104745)

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**Author:** [@JOY-8831](https://discourse.julialang.org/u/JOY-8831)\
**Replies:** 0\
**Last updated:** [October 9, 2023, 8:27am UTC](https://discourse.julialang.org/t/lwfbrook90-simulation-questions-2-plotting-and-csv-saving/104745 "2023-10-09T08:27:06Z")

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Hi I am using LWFBrook90 v1.9 to simulate the hydro-dynamics. I have some questions about the plots. These are the scripts I am using: using LWFBrook90 using OrdinaryDiffEq: solve using DataFrames using CSV using P…

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## [Any general ideas about reducing GC time involving DataFrames?](https://discourse.julialang.org/t/any-general-ideas-about-reducing-gc-time-involving-dataframes/104740)

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**Author:** [@liuyxpp](https://discourse.julialang.org/u/liuyxpp)\
**Replies:** 2\
**Last updated:** [October 9, 2023, 1:57am UTC](https://discourse.julialang.org/t/any-general-ideas-about-reducing-gc-time-involving-dataframes/104740 "2023-10-09T01:57:40Z")

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Say I have thousands of CSV files to be processed. For each, I will read the file into a Dataframe, process it, and then store the results in another DataFrame. During this process, it seems two main allocations (one for…

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## [\[RFC\] GraphInterface.jl: An interface proposal for Graphs.jl version 2.0](https://discourse.julialang.org/t/rfc-graphinterface-jl-an-interface-proposal-for-graphs-jl-version-2-0/104518)

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**Author:** [@CameronBieganek](https://discourse.julialang.org/u/CameronBieganek)\
**Replies:** 29\
**Last updated:** [October 8, 2023, 10:00pm UTC](https://discourse.julialang.org/t/rfc-graphinterface-jl-an-interface-proposal-for-graphs-jl-version-2-0/104518 "2023-10-08T22:00:07Z")

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Hi, all! I’ve created a new package GraphInterface.jl as a proposal for the new AbstractGraph interface for Graphs.jl version 2.0. I know that there is ongoing work in the GraphsBase.jl repository on the new version 2.0 …

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## [Plot function (from Plots) fails for simple trigonometry](https://discourse.julialang.org/t/plot-function-from-plots-fails-for-simple-trigonometry/104723)

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**Author:** [@StevenSiew](https://discourse.julialang.org/u/StevenSiew)\
**Replies:** 10\
**Last updated:** [October 8, 2023, 7:44pm UTC](https://discourse.julialang.org/t/plot-function-from-plots-fails-for-simple-trigonometry/104723 "2023-10-08T19:44:28Z")

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plot(0:0.1:2pi,\[sin(x)^1+cos(x)^1 for x=0:0.1:2pi\]) gives you But julia\> plot(0:0.1:2pi,\[sin(x)^2+cos(x)^2 for x=0:0.1:2pi\]) ┌ Warning: No strict ticks found └ @ PlotUtils ~/.julia/packages/PlotUtils/bZEEj/src/ticks…

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## [Meta — Computational Photonics Research Scientist](https://discourse.julialang.org/t/meta-computational-photonics-research-scientist/104734)

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**Author:** [@smartalecH](https://discourse.julialang.org/u/smartalecH)\
**Replies:** 0\
**Last updated:** [October 8, 2023, 7:43pm UTC](https://discourse.julialang.org/t/meta-computational-photonics-research-scientist/104734 "2023-10-08T19:43:38Z")

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My team at Meta Reality Labs Research is looking to hire a recent PhD grad specializing in computational photonics (FDTD, FEM, etc) for inverse design (eg using adjoint methods and autodiff). We use a variety of softwar…

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## [Sum of temperature values with Unitful.jl](https://discourse.julialang.org/t/sum-of-temperature-values-with-unitful-jl/104714)

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**Author:** [@fnoessler](https://discourse.julialang.org/u/fnoessler)\
**Replies:** 3\
**Last updated:** [October 8, 2023, 6:37pm UTC](https://discourse.julialang.org/t/sum-of-temperature-values-with-unitful-jl/104714 "2023-10-08T18:37:13Z")

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Hello, is there a way to calculate the (cumulative) sum of temperature values in °C with Unitful.jl? I know this does not have a direct physical meaning. Nonetheless, it would be nice to keep the °C unit attached to my…

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## [How do I find which packages are preventing DataFrames.jl from updating?](https://discourse.julialang.org/t/how-do-i-find-which-packages-are-preventing-dataframes-jl-from-updating/104703)

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**Author:** [@Soldalma](https://discourse.julialang.org/u/Soldalma)\
**Replies:** 9\
**Last updated:** [October 8, 2023, 5:04pm UTC](https://discourse.julialang.org/t/how-do-i-find-which-packages-are-preventing-dataframes-jl-from-updating/104703 "2023-10-08T17:04:41Z")

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The package DataFrames.jl is stuck in version v1.3.6 in my environment. I looked at Manifest.jl and deleted all the packages I could that were dependencies. Then I tried to update DataFrames.jl and still it did not updat…

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## [What is the mechanics of \`copy\` in the thread-parallization by \`Threads.@spawn\`? Or: Problems with copy arrays in thread parallelism](https://discourse.julialang.org/t/what-is-the-mechanics-of-copy-in-the-thread-parallization-by-threads-spawn-or-problems-with-copy-arrays-in-thread-parallelism/104729)

<div class="topic-metadata">

**Author:** [@draftman9](https://discourse.julialang.org/u/draftman9)\
**Replies:** 1\
**Last updated:** [October 8, 2023, 4:40pm UTC](https://discourse.julialang.org/t/what-is-the-mechanics-of-copy-in-the-thread-parallization-by-threads-spawn-or-problems-with-copy-arrays-in-thread-parallelism/104729 "2023-10-08T16:40:19Z")

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I hope to implement a thread-parallel sample, a common example in solving time-dependent evolution problems (e.g. main\_serial in the code. Generate a matrix arr\_task over time. This matrix is updated over loop/time and …

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## [How to adjust the spacing for a plot's title and a plot's legend using Plots.jl?](https://discourse.julialang.org/t/how-to-adjust-the-spacing-for-a-plots-title-and-a-plots-legend-using-plots-jl/104667)

<div class="topic-metadata">

**Author:** [@Hugo](https://discourse.julialang.org/u/Hugo)\
**Replies:** 1\
**Last updated:** [October 8, 2023, 3:28pm UTC](https://discourse.julialang.org/t/how-to-adjust-the-spacing-for-a-plots-title-and-a-plots-legend-using-plots-jl/104667 "2023-10-08T15:28:50Z")

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I am working with Plots.jl and I’d like to have more flexibility to adjust the spacings in the plots. I provide below a short piece of code that requires Plots.jl as an example that serves to drive the point home. For t…

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## [Question about the syntax of the @constraint command](https://discourse.julialang.org/t/question-about-the-syntax-of-the-constraint-command/104700)

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**Author:** [@Artemisa\_Fontinele](https://discourse.julialang.org/u/Artemisa_Fontinele)\
**Replies:** 7\
**Last updated:** [October 8, 2023, 10:18am UTC](https://discourse.julialang.org/t/question-about-the-syntax-of-the-constraint-command/104700 "2023-10-08T10:18:13Z")

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Hey guys! I’ve just started programming in julia and I want to implement two constraints for my code using the JuMP library. The constraints are: for i in 1:N for j in 1:N If sum of Xji == 0 then sum of Xij \>=2 If …

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## [Where is backslash (\\) implemented?](https://discourse.julialang.org/t/where-is-backslash-implemented/104693)

<div class="topic-metadata">

**Author:** [@SupernovaTitanium](https://discourse.julialang.org/u/SupernovaTitanium)\
**Replies:** 9\
**Last updated:** [October 8, 2023, 8:08am UTC](https://discourse.julialang.org/t/where-is-backslash-implemented/104693 "2023-10-08T08:08:15Z")

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Hi, I’m new to Julia. Recently, I’ve used the backslash (\\) operator to solve a linear system. However, I don’t know how it is implemented. I wanted to know it so I traced the code. I am able to locate to line 1110 at j…

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## [Local bindings from stack trace?](https://discourse.julialang.org/t/local-bindings-from-stack-trace/104727)

<div class="topic-metadata">

**Author:** [@bertschi](https://discourse.julialang.org/u/bertschi)\
**Replies:** 0\
**Last updated:** [October 8, 2023, 8:01am UTC](https://discourse.julialang.org/t/local-bindings-from-stack-trace/104727 "2023-10-08T08:01:18Z")

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Is it possible to get/recover the local variable bindings in a specific stack frame from a StackTrace? I know there is Base.@locals, but this just stores the local bindings at its specific call site. Thus, it doesn’t pr…

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