# Latest

**URL:** https://discourse.julialang.org/latest.md?page=270

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

**Page:** 271

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## [Juliacall with SB3 for RL in WSL bings to segmetation fault problems](https://discourse.julialang.org/t/juliacall-with-sb3-for-rl-in-wsl-bings-to-segmetation-fault-problems/122989)

<div class="topic-metadata">

**Author:** [@Claudio](https://discourse.julialang.org/u/Claudio)\
**Replies:** 0\
**Last updated:** [November 23, 2024, 10:41am UTC](https://discourse.julialang.org/t/juliacall-with-sb3-for-rl-in-wsl-bings-to-segmetation-fault-problems/122989 "2024-11-23T10:41:49Z")

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I am trying to train a RL agent using SB3, torch, and Gymnasium. I use a linux environment through wsl2 (Ubuntu-22.04), and VisualStudio Code. To speed up the step phase in my environment, I invoke Julia passing through …

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## [I want to understand Julia type system, I need some guide for this quest](https://discourse.julialang.org/t/i-want-to-understand-julia-type-system-i-need-some-guide-for-this-quest/121854)

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**Author:** [@KZiemian](https://discourse.julialang.org/u/KZiemian)\
**Replies:** 4\
**Last updated:** [November 23, 2024, 9:53am UTC](https://discourse.julialang.org/t/i-want-to-understand-julia-type-system-i-need-some-guide-for-this-quest/121854 "2024-11-23T09:53:50Z")

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I must say that I’m intrigued by Julia type system and I want to understand it more. In particular I want to understand works like this of prof. Jan Vitek and his collaborators mentioned in his 2021 JuliaCon keynote and …

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## [Implementing the log-sum-exp function](https://discourse.julialang.org/t/implementing-the-log-sum-exp-function/122946)

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**Author:** [@kangqiu](https://discourse.julialang.org/u/kangqiu)\
**Replies:** 10\
**Last updated:** [November 23, 2024, 9:23am UTC](https://discourse.julialang.org/t/implementing-the-log-sum-exp-function/122946 "2024-11-23T09:23:55Z")

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Hi everyone! I am working on stochastic model predictive control in Julia/JuMP. I am using essentially a log-sum-exp function in the objective and encountered some issues with overflow. Now I am trying to implement a re…

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## [Pivoted Cholesky: Why is rank a private field/property?](https://discourse.julialang.org/t/pivoted-cholesky-why-is-rank-a-private-field-property/122971)

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**Author:** [@ajinkya-k](https://discourse.julialang.org/u/ajinkya-k)\
**Replies:** 6\
**Last updated:** [November 23, 2024, 7:06am UTC](https://discourse.julialang.org/t/pivoted-cholesky-why-is-rank-a-private-field-property/122971 "2024-11-23T07:06:35Z")

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Hello! I am posting for the first time so please forgive me if this is naive. I am using the cholesky function with pivoting to (1) factorize a positive semidefinite matrix, (2) get its rank, and (3) do some follow-up c…

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## [Setting the foreground color of colorbar tick marks](https://discourse.julialang.org/t/setting-the-foreground-color-of-colorbar-tick-marks/122911)

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**Author:** [@marcusps](https://discourse.julialang.org/u/marcusps)\
**Replies:** 5\
**Last updated:** [November 22, 2024, 10:57pm UTC](https://discourse.julialang.org/t/setting-the-foreground-color-of-colorbar-tick-marks/122911 "2024-11-22T22:57:23Z")

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I am trying to make plot some data on black background, and setting fg\_color to :white works well except for one details. The tick marks on the color bar remain black, and thus are rendered essentially invisible. The la…

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## [How to wrap C++ function writing to FILE\*?](https://discourse.julialang.org/t/how-to-wrap-c-function-writing-to-file/122945)

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**Author:** [@Vasily\_Pisarev](https://discourse.julialang.org/u/Vasily_Pisarev)\
**Replies:** 1\
**Last updated:** [November 22, 2024, 9:11pm UTC](https://discourse.julialang.org/t/how-to-wrap-c-function-writing-to-file/122945 "2024-11-22T21:11:53Z")

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I want to wrap a C++ function writing to a file stream to be able to print to a file or to stdout (eventually I’d like to try if redirect\_stdout would work to make it print to a custom buffer). However, CxxWrap does not …

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## [Comparing model solutions - Validating solutions](https://discourse.julialang.org/t/comparing-model-solutions-validating-solutions/122294)

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**Author:** [@daro.slai](https://discourse.julialang.org/u/daro.slai)\
**Replies:** 6\
**Last updated:** [November 22, 2024, 9:37pm UTC](https://discourse.julialang.org/t/comparing-model-solutions-validating-solutions/122294 "2024-11-22T21:37:48Z")

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Hi! I’m working on an MINLP model and solving it with KNITRO. Since it’s an MINLP, the solver solution heavily depends on solver settings and I’m looking for new ways to validate it. I was trying to take the same mode…

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## [Robust and adaptive optimization support?](https://discourse.julialang.org/t/robust-and-adaptive-optimization-support/122965)

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**Author:** [@karlzhu](https://discourse.julialang.org/u/karlzhu)\
**Replies:** 3\
**Last updated:** [November 22, 2024, 9:24pm UTC](https://discourse.julialang.org/t/robust-and-adaptive-optimization-support/122965 "2024-11-22T21:24:35Z")

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Are there any currently maintained packages that extend JuMP and formulate robust and adaptive optimization models? I see there’s a JuMPeR package built many years ago, but I heard it’s unusable since it’s quite outdated…

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## [Plots.contourf and PlotlyJS.contour behaviour with regard to the x,y,z input](https://discourse.julialang.org/t/plots-contourf-and-plotlyjs-contour-behaviour-with-regard-to-the-x-y-z-input/122897)

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**Author:** [@Valery](https://discourse.julialang.org/u/Valery)\
**Replies:** 1\
**Last updated:** [November 22, 2024, 7:17pm UTC](https://discourse.julialang.org/t/plots-contourf-and-plotlyjs-contour-behaviour-with-regard-to-the-x-y-z-input/122897 "2024-11-22T19:17:52Z")

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I have been using PlotlyJS.contour() in a program to plot data, but I need to switch to Plot.contourf(). I use PlotlyJS.contour(x=x,y=y,z=z) such that x::Vector and y::Vector contain the x and y coordinates of the point…

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## [Transforming a daily DataFrame with missing values into a DataFrame with end-of-month values](https://discourse.julialang.org/t/transforming-a-daily-dataframe-with-missing-values-into-a-dataframe-with-end-of-month-values/122870)

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**Author:** [@askvorts](https://discourse.julialang.org/u/askvorts)\
**Replies:** 11\
**Last updated:** [November 22, 2024, 4:15pm UTC](https://discourse.julialang.org/t/transforming-a-daily-dataframe-with-missing-values-into-a-dataframe-with-end-of-month-values/122870 "2024-11-22T16:15:51Z")

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I am trying to transform a daily DataFrame (df) into a monthly DataFrame (monthly\_df) with end-of-month values. The following code works: monthly\_df = df\[findall(date -\> date == lastdayofmonth(date), df.date), :\] Howev…

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## [REPL hangs in Julia 1.11](https://discourse.julialang.org/t/repl-hangs-in-julia-1-11/122921)

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**Author:** [@longemen3000](https://discourse.julialang.org/u/longemen3000)\
**Replies:** 2\
**Last updated:** [November 22, 2024, 3:31am UTC](https://discourse.julialang.org/t/repl-hangs-in-julia-1-11/122921 "2024-11-22T03:31:16Z")

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Hello, I’m experiencing some failures in compilation, the REPL freezes when executing this code: julia\> using Clapeyron julia\> model = PCSAFT("water"); julia\> saturation\_pressure(model, 298.0) #REPL freezes here Using…

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## [How to simplify a symbolic expression](https://discourse.julialang.org/t/how-to-simplify-a-symbolic-expression/104381)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 11\
**Last updated:** [November 22, 2024, 3:46pm UTC](https://discourse.julialang.org/t/how-to-simplify-a-symbolic-expression/104381 "2024-11-22T15:46:16Z")

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I want to simplify an expression by replacing a sub-expression with a new variable, called Q. The following code doesn’t work: # simplify an expression using Symbolics @variables t @syms ω(t) Pg(t) Pge(t) Pgc(t) @vari…

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## [Out of VRAM (CUDA) when training MLJ + XGBoost.jl](https://discourse.julialang.org/t/out-of-vram-cuda-when-training-mlj-xgboost-jl/122966)

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**Author:** [@jling](https://discourse.julialang.org/u/jling)\
**Replies:** 0\
**Last updated:** [November 22, 2024, 3:41pm UTC](https://discourse.julialang.org/t/out-of-vram-cuda-when-training-mlj-xgboost-jl/122966 "2024-11-22T15:41:53Z")

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Currently hitting out of memory when training AND inferecing. When it only fails on inference, it looks like this: XGBoostError: (caller: XGBoosterPredictFromDMatrix) \[14:54:49\] /workspace/srcdir/xgboost/src/c\_api/../d…

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## [Performance issue in VS Code \[REPL\] (70x slower) \[was wrong setting\]](https://discourse.julialang.org/t/performance-issue-in-vs-code-repl-70x-slower-was-wrong-setting/122910)

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**Author:** [@johnb](https://discourse.julialang.org/u/johnb)\
**Replies:** 6\
**Last updated:** [November 22, 2024, 3:21pm UTC](https://discourse.julialang.org/t/performance-issue-in-vs-code-repl-70x-slower-was-wrong-setting/122910 "2024-11-22T15:21:26Z")

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I’m not sure exactly when this happened, but at some point, running code in the VS Code REPL became incredibly slow. A simple test I’ve been using to verify this is the mul!() function as below, but all code I’ve tried h…

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## [Breakpoint issues and best practices in VSCode](https://discourse.julialang.org/t/breakpoint-issues-and-best-practices-in-vscode/122914)

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**Author:** [@kevjzheng](https://discourse.julialang.org/u/kevjzheng)\
**Replies:** 2\
**Last updated:** [November 22, 2024, 3:15pm UTC](https://discourse.julialang.org/t/breakpoint-issues-and-best-practices-in-vscode/122914 "2024-11-22T15:15:48Z")

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I have been advocating Julia to my colleagues to switch from MATLAB. One of the biggest roadblocks for us is the breakpoint debug feature in VSCode. I personally have never gotten breakpoints to work. Below are the issu…

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## [About the type constraint of \`where\`](https://discourse.julialang.org/t/about-the-type-constraint-of-where/122958)

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**Author:** [@findmyway](https://discourse.julialang.org/u/findmyway)\
**Replies:** 8\
**Last updated:** [November 22, 2024, 2:46pm UTC](https://discourse.julialang.org/t/about-the-type-constraint-of-where/122958 "2024-11-22T14:46:03Z")

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This post was originally asked at 参数化方法的疑问 - 语言特性及语义 - Julia中文社区 Based on the doc at Methods · The Julia Language : julia\> function myappend(v::Vector{T}, x::T) where {T} return \[v..., x\] end myappend…

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## [Convert Union{Missing, String31} to DateTime](https://discourse.julialang.org/t/convert-union-missing-string31-to-datetime/122952)

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**Author:** [@Sounak\_Ghosh](https://discourse.julialang.org/u/Sounak_Ghosh)\
**Replies:** 3\
**Last updated:** [November 22, 2024, 2:02pm UTC](https://discourse.julialang.org/t/convert-union-missing-string31-to-datetime/122952 "2024-11-22T14:02:44Z")

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I have dataframe with a column which has some string values and some missing values. I wanted to convert this column into a DataTime column. I have used the following code df.dt = DateTime.(df.dt, dateformat"yyyy-mm-dd…

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## [Julia at FOSDEM?](https://discourse.julialang.org/t/julia-at-fosdem/5817)

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**Author:** [@barche](https://discourse.julialang.org/u/barche)\
**Replies:** 12\
**Last updated:** [November 22, 2024, 1:40pm UTC](https://discourse.julialang.org/t/julia-at-fosdem/5817 "2024-11-22T13:40:52Z")

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Hi all, I’m wondering if anyone is planning to attend FOSDEM in Brussels on February 3 and 4? There is also the possibility to spread the word on Julia a bit: Dev Room: Reserve a room for a day and have presentations …

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## [PhyloPlots](https://discourse.julialang.org/t/phyloplots/122916)

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**Author:** [@jtolopka](https://discourse.julialang.org/u/jtolopka)\
**Replies:** 2\
**Last updated:** [November 22, 2024, 1:14pm UTC](https://discourse.julialang.org/t/phyloplots/122916 "2024-11-22T13:14:10Z")

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Hi everyone, I’m encountering an issue when trying to precompile the “PhyloPlots” package in Julia. The image shows the error I’m getting. Has anyone encountered this issue, or can you suggest steps I might take to r…

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## [Julia Meetup in Brazil?](https://discourse.julialang.org/t/julia-meetup-in-brazil/122949)

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**Author:** [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Replies:** 2\
**Last updated:** [November 22, 2024, 12:55pm UTC](https://discourse.julialang.org/t/julia-meetup-in-brazil/122949 "2024-11-22T12:55:23Z")

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I am starting this thread to learn about the active community of Julia users in Brazil. Anyone interested in meeting up? If you live in Rio de Janeiro, let’s grab some drinks in a bar. If you live in a different place,…

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## [Adjusting structure of registered package](https://discourse.julialang.org/t/adjusting-structure-of-registered-package/122948)

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**Author:** [@Pablo\_Marchant](https://discourse.julialang.org/u/Pablo_Marchant)\
**Replies:** 4\
**Last updated:** [November 22, 2024, 12:55pm UTC](https://discourse.julialang.org/t/adjusting-structure-of-registered-package/122948 "2024-11-22T12:55:21Z")

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Hi all, I have a registered package (GitHub - orlox/StarStats.jl) which I initially setup such that the source for the package was contained in a subdirectory (see here, package itself is in the directory StarStats: Git…

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## [Cannot get HSL to work with AmplNLWriter](https://discourse.julialang.org/t/cannot-get-hsl-to-work-with-amplnlwriter/122903)

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**Author:** [@pulsipher](https://discourse.julialang.org/u/pulsipher)\
**Replies:** 8\
**Last updated:** [November 22, 2024, 11:37am UTC](https://discourse.julialang.org/t/cannot-get-hsl-to-work-with-amplnlwriter/122903 "2024-11-22T11:37:51Z")

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I have installed HSL\_jll.jl as provided by HSL and also installed HSL.jl. With this I can get Ipopt to work with ma27 when I use Ipopt directly: using JuMP, Ipopt, HSL, HSL\_jll model = Model(Ipopt.Optimizer) @variable(m…

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## [Possibility of factorization for ODEs produced by a mass action chemical reaction network](https://discourse.julialang.org/t/possibility-of-factorization-for-odes-produced-by-a-mass-action-chemical-reaction-network/122950)

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**Author:** [@adhalanay](https://discourse.julialang.org/u/adhalanay)\
**Replies:** 1\
**Last updated:** [November 22, 2024, 11:29am UTC](https://discourse.julialang.org/t/possibility-of-factorization-for-odes-produced-by-a-mass-action-chemical-reaction-network/122950 "2024-11-22T11:29:12Z")

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In the algebraic approach to mass action chemical reaction networks there is a very useful factorization of the RHS of the ODE system \\frac{dx}{dt}=Y\\cdot A\_k \\cdot \\Phi(x), where Y is the complex stoichiometric matr…

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## [Solve can not solve nonlinear symbolic equations](https://discourse.julialang.org/t/solve-can-not-solve-nonlinear-symbolic-equations/122942)

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**Author:** [@Bart\_van\_de\_Lint](https://discourse.julialang.org/u/Bart_van_de_Lint)\
**Replies:** 2\
**Last updated:** [November 22, 2024, 11:27am UTC](https://discourse.julialang.org/t/solve-can-not-solve-nonlinear-symbolic-equations/122942 "2024-11-22T11:27:37Z")

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It seems like symbolic\_solve doesn’t symbolically solve nonlinear equations yet. Is this a feature that will be added in the future, so that I for example could do the following? Or is there some alternative way to do th…

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## [JuliaSphere Workshop](https://discourse.julialang.org/t/juliasphere-workshop/122940)

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**Author:** [@ayushpatnaikgit](https://discourse.julialang.org/u/ayushpatnaikgit)\
**Replies:** 2\
**Last updated:** [November 22, 2024, 11:02am UTC](https://discourse.julialang.org/t/juliasphere-workshop/122940 "2024-11-22T11:02:28Z")

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xKDR Forum is a research think thank based in Mumbai. We have built several packages including: TSFrames.jl, Survey.jl, and CRRao.jl. We use these packages for our research work, as well as other Julia packages, such…

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## [Performance detoriation with the increase of array size](https://discourse.julialang.org/t/performance-detoriation-with-the-increase-of-array-size/122364)

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**Author:** [@jsjie](https://discourse.julialang.org/u/jsjie)\
**Replies:** 13\
**Last updated:** [November 22, 2024, 10:48am UTC](https://discourse.julialang.org/t/performance-detoriation-with-the-increase-of-array-size/122364 "2024-11-22T10:48:38Z")

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A MWE, in REPL, Julia 1.9.4: julia\> using BenchmarkTools julia\> function myset!(y, x, n, ind) @views for i = 1 : n x\[ind\[i\], :, :\] .= y\[:, :, i\] end …

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## [Julia v1.11.2 testing period](https://discourse.julialang.org/t/julia-v1-11-2-testing-period/122943)

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**Author:** [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)\
**Replies:** 0\
**Last updated:** [November 22, 2024, 9:45am UTC](https://discourse.julialang.org/t/julia-v1-11-2-testing-period/122943 "2024-11-22T09:45:21Z")

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The release-1.11 branch on the Julia repository now contains the set of commits we’re planning to tag as v1.11.2. The list of commits included since v1.11.1 is available here . As a patch release, it should be non-breaki…

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## [Logistic regression for data with missing values](https://discourse.julialang.org/t/logistic-regression-for-data-with-missing-values/122929)

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**Author:** [@Jakub\_Mitura](https://discourse.julialang.org/u/Jakub_Mitura)\
**Replies:** 1\
**Last updated:** [November 22, 2024, 9:34am UTC](https://discourse.julialang.org/t/logistic-regression-for-data-with-missing-values/122929 "2024-11-22T09:34:05Z")

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:100: ello I tried to adapt logistic regression for my case @model function logistic\_regression(x, y, n, σ) intercept ~ Normal(0, σ) Gabel ~ Normal(0, σ) SUVmax\_binned ~ Normal(0, σ) MTV\_binned ~ Normal…

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## [CxxWrap module rely on external dll](https://discourse.julialang.org/t/cxxwrap-module-rely-on-external-dll/122917)

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**Author:** [@Sergey](https://discourse.julialang.org/u/Sergey)\
**Replies:** 1\
**Last updated:** [November 22, 2024, 9:33am UTC](https://discourse.julialang.org/t/cxxwrap-module-rely-on-external-dll/122917 "2024-11-22T09:33:16Z")

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Hi. Is it possible to develop CxxWrap module which depend on dll lib? Since we directly load dll in jl file and one dll cant load another. module CppTypes using CxxWrap @wrapmodule(() -\> "libcore.dll", :define…

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## [Printing with nested indentation](https://discourse.julialang.org/t/printing-with-nested-indentation/122924)

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**Author:** [@jules](https://discourse.julialang.org/u/jules)\
**Replies:** 3\
**Last updated:** [November 22, 2024, 9:30am UTC](https://discourse.julialang.org/t/printing-with-nested-indentation/122924 "2024-11-22T09:30:07Z")

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Is there some generic reusable solution for the problem of printing nested objects with indentation? For example a custom show method for an array-like type where each item should be printed with an indent. But the items…

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