# Latest

**URL:** https://discourse.julialang.org/latest.md?page=738

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

**Page:** 739

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## [Building with newer LLVM](https://discourse.julialang.org/t/building-with-newer-llvm/96854)

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**Author:** [@smartalecH](https://discourse.julialang.org/u/smartalecH)\
**Replies:** 3\
**Last updated:** [March 31, 2023, 3:16am UTC](https://discourse.julialang.org/t/building-with-newer-llvm/96854 "2023-03-31T03:16:27Z")

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What’s the canonical way to build julia with a newer LLVM version (I realize this is “experimental”)? Can I just download the tarball of the version I care about, and swap it out for the default (v13 for julia\_1.8.5) in…

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## [Using JuMP for variational data assimilation -- scalability and memory usage](https://discourse.julialang.org/t/using-jump-for-variational-data-assimilation-scalability-and-memory-usage/96686)

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**Author:** [@zornsllama](https://discourse.julialang.org/u/zornsllama)\
**Replies:** 9\
**Last updated:** [March 31, 2023, 1:49am UTC](https://discourse.julialang.org/t/using-jump-for-variational-data-assimilation-scalability-and-memory-usage/96686 "2023-03-31T01:49:57Z")

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Hi! I have been using JuMP over the last few months to perform variational data assimilation. Specifically, I am trying to estimate ODE parameters by direct transcription of the equations into a nonlinear program, utiliz…

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## [Question about the usage of julia](https://discourse.julialang.org/t/question-about-the-usage-of-julia/96862)

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**Author:** [@jianqixi](https://discourse.julialang.org/u/jianqixi)\
**Replies:** 3\
**Last updated:** [March 31, 2023, 12:01am UTC](https://discourse.julialang.org/t/question-about-the-usage-of-julia/96862 "2023-03-31T00:01:42Z")

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Dear All, I know in bash, we can use cat commend to concentrate some strings into one file, like: cat \> file.name \<\<! Hello world a+b+c+… ! I am wondering in Julia, can we do a similar way to achieve the goal? Thank…

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## [Simple Graphics Library](https://discourse.julialang.org/t/simple-graphics-library/96853)

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**Author:** [@Melancholic\_Octopus](https://discourse.julialang.org/u/Melancholic_Octopus)\
**Replies:** 3\
**Last updated:** [March 30, 2023, 8:30pm UTC](https://discourse.julialang.org/t/simple-graphics-library/96853 "2023-03-30T20:30:48Z")

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I would like to try do some windowed appications, and i would like a very simple graphics library. Idealy, it would just take an array as an image, and give me events, and everything else i would handle myself. I stumbl…

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## [HTTP.jl. Can I get r::Request object before HTTP.request()](https://discourse.julialang.org/t/http-jl-can-i-get-r-request-object-before-http-request/96783)

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**Author:** [@andrey2185](https://discourse.julialang.org/u/andrey2185)\
**Replies:** 1\
**Last updated:** [March 30, 2023, 8:10pm UTC](https://discourse.julialang.org/t/http-jl-can-i-get-r-request-object-before-http-request/96783 "2023-03-30T20:10:19Z")

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Hello, can I get r::Request object before HTTP.request() ? now only: import HTTP response = HTTP.request("GET", "https://docs.julialang.org/") request = response.request somewhere about: import HTTP request = ... ? …

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## [PyCall Workaround for Automatic Conversion, Looking for Alternative](https://discourse.julialang.org/t/pycall-workaround-for-automatic-conversion-looking-for-alternative/96855)

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**Author:** [@isaac.rubberducky](https://discourse.julialang.org/u/isaac.rubberducky)\
**Replies:** 3\
**Last updated:** [March 30, 2023, 7:41pm UTC](https://discourse.julialang.org/t/pycall-workaround-for-automatic-conversion-looking-for-alternative/96855 "2023-03-30T19:41:55Z")

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So here is a solved problem, but it feels like I have solved it incorrectly, and I would love to know if there is a better way. I want to create a PyObject using the Body constructor from this library. Here is a basic M…

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## [Declaration of CUDA variables in module results in undefined reference](https://discourse.julialang.org/t/declaration-of-cuda-variables-in-module-results-in-undefined-reference/96765)

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**Author:** [@dcasbol](https://discourse.julialang.org/u/dcasbol)\
**Replies:** 3\
**Last updated:** [March 30, 2023, 6:53pm UTC](https://discourse.julialang.org/t/declaration-of-cuda-variables-in-module-results-in-undefined-reference/96765 "2023-03-30T18:53:41Z")

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Hi everyone, I am working on a project that makes intensive use of GPU computation and we wanted to have some module constants that were already placed on the GPU memory, but apparently the memory is freed after the mod…

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## [Parametric types - type definition in struct name or struct argument?](https://discourse.julialang.org/t/parametric-types-type-definition-in-struct-name-or-struct-argument/96823)

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**Author:** [@sadish-d](https://discourse.julialang.org/u/sadish-d)\
**Replies:** 8\
**Last updated:** [March 30, 2023, 6:32pm UTC](https://discourse.julialang.org/t/parametric-types-type-definition-in-struct-name-or-struct-argument/96823 "2023-03-30T18:32:06Z")

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Hi. I am new to Julia and have extremely basic computer science knowledge. I am trying to learn about parametric typing. I’ve done a reasonable amount of internet search and read the documents. Here are two cases which c…

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## [Compiler optimizations for ComplexF64 vs Fortran](https://discourse.julialang.org/t/compiler-optimizations-for-complexf64-vs-fortran/96346)

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**Author:** [@bremez](https://discourse.julialang.org/u/bremez)\
**Replies:** 7\
**Last updated:** [March 30, 2023, 6:23pm UTC](https://discourse.julialang.org/t/compiler-optimizations-for-complexf64-vs-fortran/96346 "2023-03-30T18:23:49Z")

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My former colleague Michael Rutter now posted his comparison of Fortran compilers regarding their optimization of complex number arithmetic. I was wondering if anyone would like to see how Julia matches these? For examp…

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## [Parellelization for large ODEs, Multithreading fails](https://discourse.julialang.org/t/parellelization-for-large-odes-multithreading-fails/96811)

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**Author:** [@Rezair](https://discourse.julialang.org/u/Rezair)\
**Replies:** 16\
**Last updated:** [March 30, 2023, 5:49pm UTC](https://discourse.julialang.org/t/parellelization-for-large-odes-multithreading-fails/96811 "2023-03-30T17:49:48Z")

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Hey everyone, I am new to Julia and I wanted to solve a large ODE as fast as possible. I’ve tried multithreading using Threads.@threads and EnsembleThreads() approaches, but they both reduce performance. I’ve also tried …

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## [Sm90 (H100) support for cuda.jl](https://discourse.julialang.org/t/sm90-h100-support-for-cuda-jl/96809)

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**Author:** [@smartalecH](https://discourse.julialang.org/u/smartalecH)\
**Replies:** 3\
**Last updated:** [March 30, 2023, 5:43pm UTC](https://discourse.julialang.org/t/sm90-h100-support-for-cuda-jl/96809 "2023-03-30T17:43:55Z")

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Does CUDA.jl not yet support Hopper gpus (sm90)? I get the following error when trying to execute any kernels: ERROR: LoadError: CUDA error: device kernel image is invalid (code 300, ERROR\_INVALID\_SOURCE) Here’s my en…

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## [\`\`\`@turbo\`\`\` producing different (and wrong) results compared to \`\`\`@inbounds @simd\`\`\`](https://discourse.julialang.org/t/turbo-producing-different-and-wrong-results-compared-to-inbounds-simd/96851)

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**Author:** [@bremez](https://discourse.julialang.org/u/bremez)\
**Replies:** 3\
**Last updated:** [March 30, 2023, 5:34pm UTC](https://discourse.julialang.org/t/turbo-producing-different-and-wrong-results-compared-to-inbounds-simd/96851 "2023-03-30T17:34:30Z")

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I have a use case where an integer array contains only values between 1 and some maxValue, and I would like the histogram of the array values. I found that counts(array, maxValue) was too slow, and as best as I could und…

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## [Stockwell Transform in Julia](https://discourse.julialang.org/t/stockwell-transform-in-julia/96847)

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**Author:** [@marianoarnaiz](https://discourse.julialang.org/u/marianoarnaiz)\
**Replies:** 1\
**Last updated:** [March 30, 2023, 5:17pm UTC](https://discourse.julialang.org/t/stockwell-transform-in-julia/96847 "2023-03-30T17:17:32Z")

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Hi all. Any one has a Stockwell Transform code? I need to apply it to denoise some time signals :slight\_smile: Thanks! https://en.wikipedia.org/wiki/S\_transform

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## [Advanced Tutorials: PINNs](https://discourse.julialang.org/t/advanced-tutorials-pinns/80595)

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**Author:** [@LeoCott](https://discourse.julialang.org/u/LeoCott)\
**Replies:** 14\
**Last updated:** [March 30, 2023, 4:34pm UTC](https://discourse.julialang.org/t/advanced-tutorials-pinns/80595 "2023-03-30T16:34:26Z")

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Dear all, I am quite new to Julia so I maybe missed the proper documentation. May anyone suggest advanced Julia tutorials for Physics-Informed NN (a GitHub repository or something else) ? For instance, problems with co…

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## [Multithreading agents.jl with @threads for all agents](https://discourse.julialang.org/t/multithreading-agents-jl-with-threads-for-all-agents/96845)

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**Author:** [@stockholm](https://discourse.julialang.org/u/stockholm)\
**Replies:** 4\
**Last updated:** [March 30, 2023, 3:58pm UTC](https://discourse.julialang.org/t/multithreading-agents-jl-with-threads-for-all-agents/96845 "2023-03-30T15:58:06Z")

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My agents.jl users are loosely coupled. It should be possible to run them mostly in parallel. The only congestion point is the model variable, where their computational results are summed up. So I introduced @threads to…

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## [\[ANN\] PowerNetworkMatrices.jl A collection of methods to calculate network matrices commonly used in Power Systems modeling](https://discourse.julialang.org/t/ann-powernetworkmatrices-jl-a-collection-of-methods-to-calculate-network-matrices-commonly-used-in-power-systems-modeling/96848)

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**Author:** [@jdlara-berkeley](https://discourse.julialang.org/u/jdlara-berkeley)\
**Replies:** 0\
**Last updated:** [March 30, 2023, 3:47pm UTC](https://discourse.julialang.org/t/ann-powernetworkmatrices-jl-a-collection-of-methods-to-calculate-network-matrices-commonly-used-in-power-systems-modeling/96848 "2023-03-30T15:47:53Z")

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Check out the new package PowerNetworkMatrices where we implemented a series of methods to calculate the classically used network matrices in PowerSystems PTDF, LODF, Ybus and other. The methods are implemented with sca…

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## [Accuracy of method of integration DifferentialEquations.jl](https://discourse.julialang.org/t/accuracy-of-method-of-integration-differentialequations-jl/96833)

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**Author:** [@Sergey\_Novak](https://discourse.julialang.org/u/Sergey_Novak)\
**Replies:** 8\
**Last updated:** [March 30, 2023, 3:40pm UTC](https://discourse.julialang.org/t/accuracy-of-method-of-integration-differentialequations-jl/96833 "2023-03-30T15:40:26Z")

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I have limit cycle in phase space, when i scale trajectory in phase space i see different lines. This is due to the accuracy of the integration method or this is problem of CairoMakie? Code: function Res(u, p, t)…

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## [Question about type stability and struct](https://discourse.julialang.org/t/question-about-type-stability-and-struct/96834)

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**Author:** [@fdekerme](https://discourse.julialang.org/u/fdekerme)\
**Replies:** 2\
**Last updated:** [March 30, 2023, 1:07pm UTC](https://discourse.julialang.org/t/question-about-type-stability-and-struct/96834 "2023-03-30T13:07:21Z")

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Hello ! :smiley: How do you achieve type stability with handwritten structures? For example, in the following code example, what do I need to return in the second return for the function test to be type stable? It retu…

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## [Singleton Types](https://discourse.julialang.org/t/singleton-types/96817)

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**Author:** [@olynch](https://discourse.julialang.org/u/olynch)\
**Replies:** 6\
**Last updated:** [March 30, 2023, 1:02pm UTC](https://discourse.julialang.org/t/singleton-types/96817 "2023-03-30T13:02:43Z")

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Often I want to use zero-sized structs for dispatch purposes, and it’s kind of annoying to have to make up a name for both the struct and the unique instance of that struct. In Scala, they have object as a primitive, wh…

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## [Why does using structs increase allocations (and calculation time)](https://discourse.julialang.org/t/why-does-using-structs-increase-allocations-and-calculation-time/96843)

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**Author:** [@Thomas\_Van\_Giel](https://discourse.julialang.org/u/Thomas_Van_Giel)\
**Replies:** 1\
**Last updated:** [March 30, 2023, 12:52pm UTC](https://discourse.julialang.org/t/why-does-using-structs-increase-allocations-and-calculation-time/96843 "2023-03-30T12:52:50Z")

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In an effort to make my code more easily extensible, I started using more structs containing the important arrays/data as parameters for my simulations, instead of the individual arrays. Initially my old code looked lik…

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## [How do I share a script with multiple local dependencies?](https://discourse.julialang.org/t/how-do-i-share-a-script-with-multiple-local-dependencies/96810)

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**Author:** [@minetest2048](https://discourse.julialang.org/u/minetest2048)\
**Replies:** 2\
**Last updated:** [March 30, 2023, 12:41pm UTC](https://discourse.julialang.org/t/how-do-i-share-a-script-with-multiple-local-dependencies/96810 "2023-03-30T12:41:35Z")

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I’m currently developing a script with a lot of dependencies that are locally edited, some in .julia/dev, some in the working directory of the script. The problem is that if I just give my working directory with Manifes…

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## [4D dataset plotting](https://discourse.julialang.org/t/4d-dataset-plotting/96841)

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**Author:** [@abehersan](https://discourse.julialang.org/u/abehersan)\
**Replies:** 1\
**Last updated:** [March 30, 2023, 11:48am UTC](https://discourse.julialang.org/t/4d-dataset-plotting/96841 "2023-03-30T11:48:27Z")

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Hi! I have 4D experimental data that I would like to plot just like in the figure below. Does anyone have an idea how this could be done with Plots.jl? It is basically a superposition of three 3D heatmaps for which so…

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## [Error in Gridap](https://discourse.julialang.org/t/error-in-gridap/96840)

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**Author:** [@larsudb](https://discourse.julialang.org/u/larsudb)\
**Replies:** 0\
**Last updated:** [March 30, 2023, 11:33am UTC](https://discourse.julialang.org/t/error-in-gridap/96840 "2023-03-30T11:33:49Z")

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Hi All I get the following very long error message: ERROR: MethodError: no method matching Float64(::VectorValue{2, Float64}) Closest candidates are: (::Type{T})(::T) where T\<:Number at boot.jl:760 (::Type{T})(::Vec…

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## [PyCall pyimport segfault for the poliastro module](https://discourse.julialang.org/t/pycall-pyimport-segfault-for-the-poliastro-module/96812)

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**Author:** [@isaac.rubberducky](https://discourse.julialang.org/u/isaac.rubberducky)\
**Replies:** 2\
**Last updated:** [March 30, 2023, 11:02am UTC](https://discourse.julialang.org/t/pycall-pyimport-segfault-for-the-poliastro-module/96812 "2023-03-30T11:02:06Z")

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I am trying to use the package poliastro with PyCall. The following lines of code work fine: using PyCall poliastro\_body = pyimport("poliastro.bodies") poliastro\_planes = pyimport("poliastro.frames") These do not: p…

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## [Indices of a sub-dataframe](https://discourse.julialang.org/t/indices-of-a-sub-dataframe/96650)

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**Author:** [@johnbb](https://discourse.julialang.org/u/johnbb)\
**Replies:** 23\
**Last updated:** [March 30, 2023, 10:33am UTC](https://discourse.julialang.org/t/indices-of-a-sub-dataframe/96650 "2023-03-30T10:33:20Z")

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Assume I have two dataframes A and B where A is a subset of B. How can I get the rowindices of A?

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## [How to cite a paper in julia markdown](https://discourse.julialang.org/t/how-to-cite-a-paper-in-julia-markdown/96835)

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**Author:** [@korilium](https://discourse.julialang.org/u/korilium)\
**Replies:** 0\
**Last updated:** [March 30, 2023, 9:48am UTC](https://discourse.julialang.org/t/how-to-cite-a-paper-in-julia-markdown/96835 "2023-03-30T09:48:50Z")

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I want to cite certain papers in a Julia markdown file, but I do not know how. I usually use jupyter book for it where it is thoroughly explained. Can somebody help me with this? Kind regards, Korilium

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## [Array Comprehension Problem](https://discourse.julialang.org/t/array-comprehension-problem/96822)

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**Author:** [@alekee](https://discourse.julialang.org/u/alekee)\
**Replies:** 3\
**Last updated:** [March 30, 2023, 8:58am UTC](https://discourse.julialang.org/t/array-comprehension-problem/96822 "2023-03-30T08:58:52Z")

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So completely new to coding and I’m currently going through the MIT courseware intro to computational thinking in Julia and I’m pretty confused how this piece of code works: Write the third method noisify(image::Abstrac…

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## [Loading a large complex matrix or array from a \*.jl file](https://discourse.julialang.org/t/loading-a-large-complex-matrix-or-array-from-a-jl-file/96828)

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**Author:** [@physh](https://discourse.julialang.org/u/physh)\
**Replies:** 3\
**Last updated:** [March 30, 2023, 8:51am UTC](https://discourse.julialang.org/t/loading-a-large-complex-matrix-or-array-from-a-jl-file/96828 "2023-03-30T08:51:42Z")

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Dear all, I hope to find some help here regarding loading a (relatively) large complex array stored together with some other parameters within a .jl file. The .jl data file has the following structure: # A comment wit…

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## [Can I remove dependency on Pkg from my package using xxx\_jll?](https://discourse.julialang.org/t/can-i-remove-dependency-on-pkg-from-my-package-using-xxx-jll/96704)

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**Author:** [@jsjie](https://discourse.julialang.org/u/jsjie)\
**Replies:** 5\
**Last updated:** [March 30, 2023, 8:36am UTC](https://discourse.julialang.org/t/can-i-remove-dependency-on-pkg-from-my-package-using-xxx-jll/96704 "2023-03-30T08:36:58Z")

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For some reason, I want to compile my package into binaries with PackageCompiler. It generally works fine, but compiled directories always include something like libgit2, which should be of no use to my package. After s…

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## [Multipliers of limit cycles](https://discourse.julialang.org/t/multipliers-of-limit-cycles/96827)

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**Author:** [@Sergey\_Novak](https://discourse.julialang.org/u/Sergey_Novak)\
**Replies:** 4\
**Last updated:** [March 30, 2023, 8:18am UTC](https://discourse.julialang.org/t/multipliers-of-limit-cycles/96827 "2023-03-30T08:18:07Z")

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Hello Are there packages for computing multipliers of limit cycles? I know about that i can calculate Poincare map with package DynamicalSystems, but how can i get multipliers of limit cycles?

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