# Latest

**URL:** https://discourse.julialang.org/latest.md?page=694

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

**Page:** 695

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## [Periodic Callback and Sensitivity](https://discourse.julialang.org/t/periodic-callback-and-sensitivity/99057)

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**Author:** [@Guido\_Ballabio](https://discourse.julialang.org/u/Guido_Ballabio)\
**Replies:** 5\
**Last updated:** [May 19, 2023, 8:40pm UTC](https://discourse.julialang.org/t/periodic-callback-and-sensitivity/99057 "2023-05-19T20:40:30Z")

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I am trying to use DiffEq and SciML sensitivity to build NN controllers for physical systems. Usually everything works, however this time I need to design a fixed-frequency controller so I’ve reached to PeriodCallback w…

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## [Error During Test in wmma.jl](https://discourse.julialang.org/t/error-during-test-in-wmma-jl/99035)

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**Author:** [@huiyuxie](https://discourse.julialang.org/u/huiyuxie)\
**Replies:** 2\
**Last updated:** [May 19, 2023, 8:11pm UTC](https://discourse.julialang.org/t/error-during-test-in-wmma-jl/99035 "2023-05-19T20:11:10Z")

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Hi! I run test CUDA to ensure that everything works as expected. But some errors occurred as below. Are these errors related to the test file or the configuration of the system? How can I resolve them? Thanks! I have…

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## [Wrong word in the manual?](https://discourse.julialang.org/t/wrong-word-in-the-manual/99123)

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**Author:** [@chskcau](https://discourse.julialang.org/u/chskcau)\
**Replies:** 1\
**Last updated:** [May 19, 2023, 6:56pm UTC](https://discourse.julialang.org/t/wrong-word-in-the-manual/99123 "2023-05-19T18:56:02Z")

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Hello, I’m just in the process of learning Julia and reading the manual, and in the section on promotion I noticed the following statement: The most common usages of promote occur in outer constructors methods, provid…

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## [MethodError in Turing.jl](https://discourse.julialang.org/t/methoderror-in-turing-jl/99075)

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**Author:** [@PeX](https://discourse.julialang.org/u/PeX)\
**Replies:** 2\
**Last updated:** [May 19, 2023, 6:41pm UTC](https://discourse.julialang.org/t/methoderror-in-turing-jl/99075 "2023-05-19T18:41:28Z")

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I’m trying to do a Bayesian inference to the following ODE system: function ice(du, u, p, t) εₘ, εₖ, σ, F, d, ε = u Aₘ, Qₘ, n, pₘ, R, T, Eₖ, Eₘ, η, dₛₛ, Fₛₛ, ε₁, ε₂, S = p du\[1\] = Aₘ \* (σ/F)^n \* d^(-pₘ) \* ℯ^(-Qₘ/(…

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## [Topology optimization in gridap for structural problem](https://discourse.julialang.org/t/topology-optimization-in-gridap-for-structural-problem/98945)

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**Author:** [@mary](https://discourse.julialang.org/u/mary)\
**Replies:** 19\
**Last updated:** [May 19, 2023, 5:16pm UTC](https://discourse.julialang.org/t/topology-optimization-in-gridap-for-structural-problem/98945 "2023-05-19T17:16:35Z")

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HI, I am using gridap package to FE and then topology optimization. i just followed the tutorial 18 of gridap but I get error as below. i really appreciate if anyone help me. also my model is 2D i dont know if i should s…

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## [What is the philosophy behind arrays not being copied when assigned to another variable?](https://discourse.julialang.org/t/what-is-the-philosophy-behind-arrays-not-being-copied-when-assigned-to-another-variable/98702)

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**Author:** [@Bizzi](https://discourse.julialang.org/u/Bizzi)\
**Replies:** 24\
**Last updated:** [May 19, 2023, 4:12pm UTC](https://discourse.julialang.org/t/what-is-the-philosophy-behind-arrays-not-being-copied-when-assigned-to-another-variable/98702 "2023-05-19T16:12:30Z")

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Very basic question, but I am hoping there might be an underlying principle which could help me understand other (at first) puzzling aspects of Julia. As a heavy Matlab and C user, it is hard to imagine why someone woul…

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## [Implementing a Trie](https://discourse.julialang.org/t/implementing-a-trie/99022)

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**Author:** [@spionkaese](https://discourse.julialang.org/u/spionkaese)\
**Replies:** 6\
**Last updated:** [May 19, 2023, 4:06pm UTC](https://discourse.julialang.org/t/implementing-a-trie/99022 "2023-05-19T16:06:10Z")

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I am currently trying to implement a (bitwise?) Trie mapping Ints to some type V, and want to branch k bits at a time (resulting in 2^k children per node). For a first attempt I went with k = 1 and my nodes looked like …

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## [JuliaCon 2023 Schedule is Released!](https://discourse.julialang.org/t/juliacon-2023-schedule-is-released/99119)

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**Author:** [@ranjan](https://discourse.julialang.org/u/ranjan)\
**Replies:** 0\
**Last updated:** [May 19, 2023, 4:00pm UTC](https://discourse.julialang.org/t/juliacon-2023-schedule-is-released/99119 "2023-05-19T16:00:13Z")

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Hey everyone, This is to inform that we released the first version of the JuliaCon 2023 schedule: https://pretalx.com/juliacon2023/schedule/. Please email us at juliacon@julialang.org for any questions. Best, Ranjan …

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## [Multithreading over multiple CPU](https://discourse.julialang.org/t/multithreading-over-multiple-cpu/99106)

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**Author:** [@astro-kevin](https://discourse.julialang.org/u/astro-kevin)\
**Replies:** 8\
**Last updated:** [May 19, 2023, 3:57pm UTC](https://discourse.julialang.org/t/multithreading-over-multiple-cpu/99106 "2023-05-19T15:57:00Z")

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Is the @threads macro available for multithreading over multiple CPU, or does it only work for setups with one CPU?

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## [Construct Tuple containing NamedTuple from Tuple](https://discourse.julialang.org/t/construct-tuple-containing-namedtuple-from-tuple/98954)

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**Author:** [@baumgold](https://discourse.julialang.org/u/baumgold)\
**Replies:** 8\
**Last updated:** [May 19, 2023, 2:46pm UTC](https://discourse.julialang.org/t/construct-tuple-containing-namedtuple-from-tuple/98954 "2023-05-19T14:46:52Z")

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I’m trying to construct a Tuple containing a member NamedTuple from a Tuple. I believe this should work but it doesn’t. julia\> T = Tuple{Int64, Int64, NamedTuple{(:d, :e), Tuple{Int64, Int64}}}; julia\> vals = (1,2,(3,…

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## [How can I avoid using global variables that will vary their values?](https://discourse.julialang.org/t/how-can-i-avoid-using-global-variables-that-will-vary-their-values/99085)

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**Author:** [@AliceandBob](https://discourse.julialang.org/u/AliceandBob)\
**Replies:** 14\
**Last updated:** [May 19, 2023, 2:21pm UTC](https://discourse.julialang.org/t/how-can-i-avoid-using-global-variables-that-will-vary-their-values/99085 "2023-05-19T14:21:45Z")

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I am using Julia to solve a quantum system with a self-consistence iteration algorithm. In my current code, many global variables and arrays are used which, from many documents, are harmful to the performance. However, I…

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## [Adding new field to existing structure](https://discourse.julialang.org/t/adding-new-field-to-existing-structure/99117)

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**Author:** [@josimar](https://discourse.julialang.org/u/josimar)\
**Replies:** 2\
**Last updated:** [May 19, 2023, 1:54pm UTC](https://discourse.julialang.org/t/adding-new-field-to-existing-structure/99117 "2023-05-19T13:54:25Z")

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I am trying to learn more about the way to organize my Julia code. I know from the documentation that I can create a structure to hold some data like this: ## The structure below has lots of fields, I am just showing on…

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## [How to make a South-up map using GeoMakie](https://discourse.julialang.org/t/how-to-make-a-south-up-map-using-geomakie/96438)

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**Author:** [@dpabon](https://discourse.julialang.org/u/dpabon)\
**Replies:** 2\
**Last updated:** [March 23, 2023, 1:15pm UTC](https://discourse.julialang.org/t/how-to-make-a-south-up-map-using-geomakie/96438 "2023-03-23T13:15:17Z")

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I would like to produce a coast-lines plot using GeoMakie like this one: or this one: I tried with the dest projection, but doesn’t work well: using CairoMakie, GeoMakie fig = Figure() ga = GeoAxis( fig\[1,…

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## [Collect for CuArray composite types](https://discourse.julialang.org/t/collect-for-cuarray-composite-types/99082)

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**Author:** [@RainerHeintzmann](https://discourse.julialang.org/u/RainerHeintzmann)\
**Replies:** 2\
**Last updated:** [May 19, 2023, 11:46am UTC](https://discourse.julialang.org/t/collect-for-cuarray-composite-types/99082 "2023-05-19T11:46:44Z")

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Using CUDA.jl single index access is discouraged for good reasons. However, if I want to implement a composite type (e.g. ShiftedArrays.jl) to work well with CuArray it needs to support collect. Yet the collect mechanis…

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## [Minimising DifferentialEquations GPU memory allocation](https://discourse.julialang.org/t/minimising-differentialequations-gpu-memory-allocation/99050)

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**Author:** [@Tommy\_Fischer](https://discourse.julialang.org/u/Tommy_Fischer)\
**Replies:** 8\
**Last updated:** [May 19, 2023, 10:08am UTC](https://discourse.julialang.org/t/minimising-differentialequations-gpu-memory-allocation/99050 "2023-05-19T10:08:46Z")

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I’m simulating the Gross-Pitaevskii Equation for a three-dimensional array with M^3 values, and am running into some issues with GPU memory for large M values. In short, I’m wondering if there is anything more I can do t…

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## [Julia spawn several commands](https://discourse.julialang.org/t/julia-spawn-several-commands/7421)

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**Author:** [@tawheeler](https://discourse.julialang.org/u/tawheeler)\
**Replies:** 9\
**Last updated:** [May 19, 2023, 9:19am UTC](https://discourse.julialang.org/t/julia-spawn-several-commands/7421 "2023-05-19T09:19:57Z")

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Hi Julia users, I would like to run a command that is actually several commands separated by semi-colons. ex: run(\`ls; ls\`) I get an error that semi-colons needs to be quoted. run('ls; ls') does not work run(ls';' …

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## [Why no canvas popping up with Plots](https://discourse.julialang.org/t/why-no-canvas-popping-up-with-plots/99059)

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**Author:** [@Elisabeth](https://discourse.julialang.org/u/Elisabeth)\
**Replies:** 9\
**Last updated:** [May 19, 2023, 9:10am UTC](https://discourse.julialang.org/t/why-no-canvas-popping-up-with-plots/99059 "2023-05-19T09:10:17Z")

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Hi every one I hope you can help me out. I’m new to Julia and new to vs code. Running a simple program in vs code using plots, no plot pane shows up. If I run it in the julia terminal line by line it does show up but ru…

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## [Recompile generated function when methods get defined](https://discourse.julialang.org/t/recompile-generated-function-when-methods-get-defined/99089)

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**Author:** [@aplavin](https://discourse.julialang.org/u/aplavin)\
**Replies:** 6\
**Last updated:** [May 19, 2023, 8:32am UTC](https://discourse.julialang.org/t/recompile-generated-function-when-methods-get-defined/99089 "2023-05-19T08:32:49Z")

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Normally, generated functions can only use methods defined earlier: julia\> f(x) = 1 julia\> @generated g(x...) = f(x...) julia\> f(x, y) = 2 julia\> g(1) 1 julia\> g(1, 1) ERROR: MethodError: no method matching f(::Type{In…

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## [Installing PythonPlot fails](https://discourse.julialang.org/t/installing-pythonplot-fails/99100)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 0\
**Last updated:** [May 19, 2023, 8:32am UTC](https://discourse.julialang.org/t/installing-pythonplot-fails/99100 "2023-05-19T08:32:35Z")

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Precompiling PythonPlot on Windows with Julia 1.9 fails: (WindTurbines) pkg\> precompile Precompiling project... ✗ PythonPlot 0 dependencies successfully precompiled in 4 seconds. 201 already precompiled. ERROR: The…

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## [DateTime: how to handle "yymmdd" format?](https://discourse.julialang.org/t/datetime-how-to-handle-yymmdd-format/99074)

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**Author:** [@ryofurue](https://discourse.julialang.org/u/ryofurue)\
**Replies:** 5\
**Last updated:** [May 19, 2023, 7:51am UTC](https://discourse.julialang.org/t/datetime-how-to-handle-yymmdd-format/99074 "2023-05-19T07:51:34Z")

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I have to read a text data which uses the “yymmdd” format for the date. For example the date 2023-05-19 is expressed as “230519” in the file. How does one convert the string to a DateTime object? In Julia’s Dates packag…

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## [The board of NeuroImage resigns: Academics should pay attention](https://discourse.julialang.org/t/the-board-of-neuroimage-resigns-academics-should-pay-attention/98626)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 19\
**Last updated:** [May 19, 2023, 7:34am UTC](https://discourse.julialang.org/t/the-board-of-neuroimage-resigns-academics-should-pay-attention/98626 "2023-05-19T07:34:20Z")

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Some of the publishers out there are just outrageous. (This is the pitch: “You do all the work, for which we charge you £2,700 per article. And don’t worry, this money is not wasted, it will end up as a 40% profit marg…

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## [Performance of IdDict vs Dict](https://discourse.julialang.org/t/performance-of-iddict-vs-dict/57589)

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**Author:** [@DrChainsaw](https://discourse.julialang.org/u/DrChainsaw)\
**Replies:** 13\
**Last updated:** [May 19, 2023, 5:18am UTC](https://discourse.julialang.org/t/performance-of-iddict-vs-dict/57589 "2023-05-19T05:18:53Z")

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I have always lazily assumed that IdDict would always be faster if keying by identity is desired, but it seems like this is not the case: julia\> function benchmarkdict(DType, ks) d = DType(k =\> k for k in ks)…

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## [Problem in reading data with DLMreader package](https://discourse.julialang.org/t/problem-in-reading-data-with-dlmreader-package/99096)

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**Author:** [@akshdfyehd](https://discourse.julialang.org/u/akshdfyehd)\
**Replies:** 0\
**Last updated:** [May 19, 2023, 5:05am UTC](https://discourse.julialang.org/t/problem-in-reading-data-with-dlmreader-package/99096 "2023-05-19T05:05:03Z")

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Hi, I have the data in 11th and 13th (accommodation cost and transportation cost) column with , and USD and $ which I would like to remove, my tutor have asked specifically using DLMReader package, informat function, I h…

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## [Windows 11 versus WSL2: Need for Speed](https://discourse.julialang.org/t/windows-11-versus-wsl2-need-for-speed/99086)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 1\
**Last updated:** [May 18, 2023, 10:17pm UTC](https://discourse.julialang.org/t/windows-11-versus-wsl2-need-for-speed/99086 "2023-05-18T22:17:45Z")

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Could one gain a significant advantage using Julia in Linux running within WSL2 compared to the Windows version? Package instantiation. 239 dependencies, always starting from blank slate (no depot). Julia Version 1.9.0…

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## [How to maximize replicability of a package](https://discourse.julialang.org/t/how-to-maximize-replicability-of-a-package/99034)

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**Author:** [@Joris\_Pinkse](https://discourse.julialang.org/u/Joris_Pinkse)\
**Replies:** 16\
**Last updated:** [May 18, 2023, 9:32pm UTC](https://discourse.julialang.org/t/how-to-maximize-replicability-of-a-package/99034 "2023-05-18T21:32:38Z")

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I’m developing a new package for a broad audience with prospective users valuing replicability/reproducibility of results. On my laptop and desktop which have different versions of Ubuntu, different hardware (AMD versus…

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## [Creating symbols from strings in Symbolics package](https://discourse.julialang.org/t/creating-symbols-from-strings-in-symbolics-package/99071)

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**Author:** [@brombo](https://discourse.julialang.org/u/brombo)\
**Replies:** 2\
**Last updated:** [May 18, 2023, 8:50pm UTC](https://discourse.julialang.org/t/creating-symbols-from-strings-in-symbolics-package/99071 "2023-05-18T20:50:58Z")

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Firstly I am talking about Num and Real symbols in the Julia Symbols package. If I am talking about coding symbols in general I know I can create then from a string by X2 = Symbol("x^2") println(X2) x^2 but in the Sym…

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## [How to create an user-defined function with multiple vector as inputs](https://discourse.julialang.org/t/how-to-create-an-user-defined-function-with-multiple-vector-as-inputs/99068)

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**Author:** [@PatrickeTownsend](https://discourse.julialang.org/u/PatrickeTownsend)\
**Replies:** 1\
**Last updated:** [May 18, 2023, 8:40pm UTC](https://discourse.julialang.org/t/how-to-create-an-user-defined-function-with-multiple-vector-as-inputs/99068 "2023-05-18T20:40:21Z")

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Hello, I’m new to JuMP module and also Julia. I’m trying to perform a trajectory optimization with Hermite-Simpson direct collocation method. I’ve trying to create a function for the dynamic equations, but I’m still get…

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## [A way for identifying the code portion being re-compiled?](https://discourse.julialang.org/t/a-way-for-identifying-the-code-portion-being-re-compiled/99077)

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**Author:** [@Atiyah](https://discourse.julialang.org/u/Atiyah)\
**Replies:** 1\
**Last updated:** [May 18, 2023, 8:29pm UTC](https://discourse.julialang.org/t/a-way-for-identifying-the-code-portion-being-re-compiled/99077 "2023-05-18T20:29:57Z")

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Motivation: I done some re-structuring to my code. Afterwords, re-executing with the @time macro within REPL indicates that part of the code is getting re-compiled, e.g. .... seconds (... , 50.63% compilation time: 100%…

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## [Sending code to REPL automatically installs packages without prompt](https://discourse.julialang.org/t/sending-code-to-repl-automatically-installs-packages-without-prompt/99072)

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**Author:** [@zalky](https://discourse.julialang.org/u/zalky)\
**Replies:** 1\
**Last updated:** [May 18, 2023, 8:21pm UTC](https://discourse.julialang.org/t/sending-code-to-repl-automatically-installs-packages-without-prompt/99072 "2023-05-18T20:21:54Z")

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Hi all, So my REPL workflow involves sending code to the Julia REPL to be evaluated into the running environment. This is in contrast to typing code into the REPL manually. Unfortunately if there’s an import SomePackag…

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## [Working with MCMCChains?](https://discourse.julialang.org/t/working-with-mcmcchains/99014)

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**Author:** [@dlakelan](https://discourse.julialang.org/u/dlakelan)\
**Replies:** 9\
**Last updated:** [May 18, 2023, 6:52pm UTC](https://discourse.julialang.org/t/working-with-mcmcchains/99014 "2023-05-18T18:52:58Z")

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Suppose I’ve fit a model with Turing and I have a “Chains” object. Suppose my model has a bunch of nuisance parameters, and I’m just interested in looking at several particular parameters. I want to extract a chains obje…

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