# Latest

**URL:** https://discourse.julialang.org/latest.md?page=858

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

**Page:** 859

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## [Question about LP format file generation](https://discourse.julialang.org/t/question-about-lp-format-file-generation/90460)

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**Author:** [@kevinqiao](https://discourse.julialang.org/u/kevinqiao)\
**Replies:** 5\
**Last updated:** [November 21, 2022, 7:14am UTC](https://discourse.julialang.org/t/question-about-lp-format-file-generation/90460 "2022-11-21T07:14:32Z")

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I’m using JuMP v1.4.0 and I want to generate an LP format file of the following model, but it doesn’t work, the file is not generated, and I don’t know why. Thanks in advance. using JuMP using Gurobi model = Model(Gur…

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## [How to export contact map/distance map in Julia?](https://discourse.julialang.org/t/how-to-export-contact-map-distance-map-in-julia/90574)

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**Author:** [@dangda](https://discourse.julialang.org/u/dangda)\
**Replies:** 0\
**Last updated:** [November 21, 2022, 6:47am UTC](https://discourse.julialang.org/t/how-to-export-contact-map-distance-map-in-julia/90574 "2022-11-21T06:47:15Z")

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I draw a protein contact map and distance map in Julia. I want to export it in a csv/png form but it doesn’t work at all. This is how I write the code using BioStructures julia\> struc=read(“ranked\_0.pdb”,PDB) cPro…

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## [Jetbrains Fleet vs VS Code](https://discourse.julialang.org/t/jetbrains-fleet-vs-vs-code/89497)

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**Author:** [@Palli](https://discourse.julialang.org/u/Palli)\
**Replies:** 1\
**Last updated:** [November 21, 2022, 5:04am UTC](https://discourse.julialang.org/t/jetbrains-fleet-vs-vs-code/89497 "2022-11-21T05:04:47Z")

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Jetbrains has good IDEs, I understand best for e.g. Java, and now Fleet. I see blog posts saying it’s good or, others not a "VS Code killer, though: Ever since it is announced many have dubbed Fleet a “VS Code killer”…

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## [MLJ Tuning and Hyperparameters , Regression](https://discourse.julialang.org/t/mlj-tuning-and-hyperparameters-regression/90546)

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**Author:** [@Mr.Benz](https://discourse.julialang.org/u/Mr.Benz)\
**Replies:** 0\
**Last updated:** [November 20, 2022, 4:16pm UTC](https://discourse.julialang.org/t/mlj-tuning-and-hyperparameters-regression/90546 "2022-11-20T16:16:01Z")

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I started with julia , new to data science. i have a quetion on MLJ tuning ang iteratied model. in a loop , Do we need to do TunedModel + IteratedModel +evaluate or IteratedModel +TunedModel +evaluate which is best wa…

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## [MLJ Tuning, MLJ](https://discourse.julialang.org/t/mlj-tuning-mlj/90544)

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**Author:** [@Mr.Benz](https://discourse.julialang.org/u/Mr.Benz)\
**Replies:** 0\
**Last updated:** [November 20, 2022, 4:06pm UTC](https://discourse.julialang.org/t/mlj-tuning-mlj/90544 "2022-11-20T16:06:14Z")

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I started with julia , new to data science. i have a quetion on MLJ tuning ang iteratied model. in a loop , Do we need to do TunedModel + IteratedModel +evaluate or IteratedModel +TunedModel +evaluate which is best…

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## [Why is qr! not available for a view?](https://discourse.julialang.org/t/why-is-qr-not-available-for-a-view/90563)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 2\
**Last updated:** [November 21, 2022, 3:24am UTC](https://discourse.julialang.org/t/why-is-qr-not-available-for-a-view/90563 "2022-11-21T03:24:24Z")

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I tried to use qr! on a view of a dense matrix, but apparently there is no method for that: LoadError: MethodError: no method matching qr!(::SubArray{Float64, 1, Matrix{Float64}, Tuple{Base.Slice{Base.OneTo{Int64}}, I…

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## [Image File Type Conversions](https://discourse.julialang.org/t/image-file-type-conversions/90554)

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**Author:** [@GameDungeon](https://discourse.julialang.org/u/GameDungeon)\
**Replies:** 1\
**Last updated:** [November 21, 2022, 1:57am UTC](https://discourse.julialang.org/t/image-file-type-conversions/90554 "2022-11-21T01:57:32Z")

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Are there any good ways to convert between image file types? For example SVG to JPG, or even a simple PNG to JPG? Edit: I guess with PNG to JPG I could just load the file and then save it. Not sure about SVG to other ty…

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## [Plummers Software Programing Language Drag Race](https://discourse.julialang.org/t/plummers-software-programing-language-drag-race/90564)

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**Author:** [@MikeeBee](https://discourse.julialang.org/u/MikeeBee)\
**Replies:** 2\
**Last updated:** [November 21, 2022, 1:26am UTC](https://discourse.julialang.org/t/plummers-software-programing-language-drag-race/90564 "2022-11-21T01:26:20Z")

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Guys, Don’t know if any of you have seen this or not. It’s a competition to see which programming language produces the fastest code. Julia doesn’t come off very well. For example, running the code on a Ryzen 9 5950X…

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## [Plots.jl GKS failing](https://discourse.julialang.org/t/plots-jl-gks-failing/90424)

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**Author:** [@alexsss](https://discourse.julialang.org/u/alexsss)\
**Replies:** 12\
**Last updated:** [November 21, 2022, 1:26am UTC](https://discourse.julialang.org/t/plots-jl-gks-failing/90424 "2022-11-21T01:26:07Z")

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Hi Having issues with the Plots.jl package after a Windows update. I receive error messages of the following form whenever I try to run any GUI command (e.g. scatter(1:10,1:10)): GKS: GKS not in proper state. GKS must …

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## [Solve a cubic equation in one variable](https://discourse.julialang.org/t/solve-a-cubic-equation-in-one-variable/90559)

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**Author:** [@GottDengDirk](https://discourse.julialang.org/u/GottDengDirk)\
**Replies:** 2\
**Last updated:** [November 20, 2022, 10:51pm UTC](https://discourse.julialang.org/t/solve-a-cubic-equation-in-one-variable/90559 "2022-11-20T22:51:49Z")

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Hi, i use PolynomialRoots.jl package. the result is but when i use Cubic Equation Calculator, there is a different result: Am I using the roots function wrong and getting different results?

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## [How to hide output from a pluto cell](https://discourse.julialang.org/t/how-to-hide-output-from-a-pluto-cell/90057)

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**Author:** [@Xavier\_Gonzalez](https://discourse.julialang.org/u/Xavier_Gonzalez)\
**Replies:** 2\
**Last updated:** [November 20, 2022, 10:04pm UTC](https://discourse.julialang.org/t/how-to-hide-output-from-a-pluto-cell/90057 "2022-11-20T22:04:49Z")

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I am using Pluto.jl I am importing some dictionaries that have as entries fairly large tensors (100x100x100). The tensors are store as BSON files, so that code is output = BSON.load(path\_to\_file); Just to make the…

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## [Documenter: how to exclude search results?](https://discourse.julialang.org/t/documenter-how-to-exclude-search-results/86785)

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**Author:** [@t-bltg](https://discourse.julialang.org/u/t-bltg)\
**Replies:** 3\
**Last updated:** [November 20, 2022, 9:36pm UTC](https://discourse.julialang.org/t/documenter-how-to-exclude-search-results/86785 "2022-11-20T21:36:55Z")

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I’d like to exclude certain pages from appearing in the search results for fixing Docs: Search results are hard to interpret for common search terms · Issue #4157 · JuliaPlots/Plots.jl · GitHub. What is the process used…

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## [Trying to figure out what a \[\] \[\] does in a macro assignment](https://discourse.julialang.org/t/trying-to-figure-out-what-a-does-in-a-macro-assignment/90556)

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**Author:** [@1153dent](https://discourse.julialang.org/u/1153dent)\
**Replies:** 4\
**Last updated:** [November 20, 2022, 8:40pm UTC](https://discourse.julialang.org/t/trying-to-figure-out-what-a-does-in-a-macro-assignment/90556 "2022-11-20T20:40:07Z")

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noob here. Trying to understand some code and am baffled as to how to figure out the utility of the TWO in the below. @use\_memo(deps::Vector{Any}) do # Expensive computation/loading end messages = @use\_memo(() -\> \[\],…

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## [Creating a new column containing DataFrames itself (e.g. from "complex" function output)](https://discourse.julialang.org/t/creating-a-new-column-containing-dataframes-itself-e-g-from-complex-function-output/90550)

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**Author:** [@mreichMPI-BGC](https://discourse.julialang.org/u/mreichMPI-BGC)\
**Replies:** 2\
**Last updated:** [November 20, 2022, 7:12pm UTC](https://discourse.julialang.org/t/creating-a-new-column-containing-dataframes-itself-e-g-from-complex-function-output/90550 "2022-11-20T19:12:02Z")

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I am not sure how to best deal with function output that is not a simple scalar, when e.g. working with combine, e.g. the follow example to Calculate deciles for each numeric variable and each group: ## Create Dataset t…

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## [Summarize all or selected columns in grouped DataFrame](https://discourse.julialang.org/t/summarize-all-or-selected-columns-in-grouped-dataframe/90509)

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**Author:** [@mreichMPI-BGC](https://discourse.julialang.org/u/mreichMPI-BGC)\
**Replies:** 8\
**Last updated:** [November 20, 2022, 6:56pm UTC](https://discourse.julialang.org/t/summarize-all-or-selected-columns-in-grouped-dataframe/90509 "2022-11-20T18:56:20Z")

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Dear community, how can I summarize all columns of a GroupedDataFrame with DataFramesMeta? Like this in DataFrames: df = DataFrame(rand(20,5), :auto) df\[!, :gr\] = repeat(1:4; inner=5) dsum=combine(groupby(df, :gr), n…

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## [\[ANN\] Implementation of the subspace iteration method for the generalized EP](https://discourse.julialang.org/t/ann-implementation-of-the-subspace-iteration-method-for-the-generalized-ep/90553)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 0\
**Last updated:** [November 20, 2022, 6:53pm UTC](https://discourse.julialang.org/t/ann-implementation-of-the-subspace-iteration-method-for-the-generalized-ep/90553 "2022-11-20T18:53:37Z")

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Interested in finding the smallest eigenvalue of the generalized EP? This package might be an alternative to Arpack. It isn’t as fast, but only a little bit slower. It is all Julia, as opposed to Arpack. If you have any…

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## [Revise.jl stopped working](https://discourse.julialang.org/t/revise-jl-stopped-working/31221)

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**Author:** [@Calum\_H](https://discourse.julialang.org/u/Calum_H)\
**Replies:** 6\
**Last updated:** [November 20, 2022, 6:38pm UTC](https://discourse.julialang.org/t/revise-jl-stopped-working/31221 "2022-11-20T18:38:27Z")

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I have been using Revise.jl for a few months on VisualStudio Code (windows). Over the weekend it has stopped working and I can’t figure out why. I’m on Julia v1.2 and Revise v2.2.2. My config/startup.jl should load Revi…

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## [JuMP set start values in new model with solution of smaller model](https://discourse.julialang.org/t/jump-set-start-values-in-new-model-with-solution-of-smaller-model/90482)

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**Author:** [@nlaws](https://discourse.julialang.org/u/nlaws)\
**Replies:** 1\
**Last updated:** [November 20, 2022, 6:20pm UTC](https://discourse.julialang.org/t/jump-set-start-values-in-new-model-with-solution-of-smaller-model/90482 "2022-11-20T18:20:20Z")

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In the JuMP docs it shows how to efficiently set start values using one model: x = all\_variables(model) x\_solution = value.(x) set\_start\_value.(x, x\_solution) However, I am looking for an efficient way to do this with …

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## [How to debug exception triggered by unit test in VSCode](https://discourse.julialang.org/t/how-to-debug-exception-triggered-by-unit-test-in-vscode/90438)

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**Author:** [@nrontsis](https://discourse.julialang.org/u/nrontsis)\
**Replies:** 1\
**Last updated:** [November 20, 2022, 6:12pm UTC](https://discourse.julialang.org/t/how-to-debug-exception-triggered-by-unit-test-in-vscode/90438 "2022-11-20T18:12:26Z")

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Suppose the following minimal example, that triggers an exception in its execution, due to the return x + 1 line: using Test function f(x) return x + 1 end @test f(\[0\]) == \[1\] I want to launch a debugging session…

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## [Allow Changing Usernames](https://discourse.julialang.org/t/allow-changing-usernames/90480)

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**Author:** [@ParadaCarleton](https://discourse.julialang.org/u/ParadaCarleton)\
**Replies:** 1\
**Last updated:** [November 20, 2022, 5:52pm UTC](https://discourse.julialang.org/t/allow-changing-usernames/90480 "2022-11-20T17:52:03Z")

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Would the Admins here be willing to allow username changes? It looks like there’s an option to allow username changes, but it has to be enabled by the administrators. Thanks!

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## [Julia 1.9.alpha1 multi thread](https://discourse.julialang.org/t/julia-1-9-alpha1-multi-thread/90526)

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**Author:** [@Mr.Benz](https://discourse.julialang.org/u/Mr.Benz)\
**Replies:** 5\
**Last updated:** [November 20, 2022, 3:00pm UTC](https://discourse.julialang.org/t/julia-1-9-alpha1-multi-thread/90526 "2022-11-20T15:00:16Z")

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I have installed julia 1.8.3 and julia 1.9.0 alpha1. when enter julia -t auto command ,julia 1.8.3 is running. how to start julia 1.9.alpha1 with mulit threads. Also,Julia 1.9.alpha1 is not supporting vs code with jup…

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## [Trend Following strategy with ETFs in Julia](https://discourse.julialang.org/t/trend-following-strategy-with-etfs-in-julia/90534)

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**Author:** [@dm13450](https://discourse.julialang.org/u/dm13450)\
**Replies:** 2\
**Last updated:** [November 20, 2022, 1:09pm UTC](https://discourse.julialang.org/t/trend-following-strategy-with-etfs-in-julia/90534 "2022-11-20T13:09:59Z")

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I’ve written a post on building out a Trend Following strategy using ETFs:

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## [Ask Whether The Plot Step function variation $x + \\lfloor x \\rfloor$ is Correct](https://discourse.julialang.org/t/ask-whether-the-plot-step-function-variation-x-lfloor-x-rfloor-is-correct/90529)

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**Author:** [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)\
**Replies:** 2\
**Last updated:** [November 20, 2022, 12:14pm UTC](https://discourse.julialang.org/t/ask-whether-the-plot-step-function-variation-x-lfloor-x-rfloor-is-correct/90529 "2022-11-20T12:14:42Z")

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Hi all I try to plot this function: x + \\lfloor x \\rfloor I have this code: using Plots,LaTeXStrings,Colors gr() f(x) = x + floor(x) x = -2:1:4 y = f.(x) plot(x\[1:2\], \[y\[1\], y\[1\]\], label=L"f(x) = x + \\lfloor x \\rfloo…

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## [Atom 1.39 won't build julia-client](https://discourse.julialang.org/t/atom-1-39-wont-build-julia-client/26696)

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**Author:** [@gabehassler](https://discourse.julialang.org/u/gabehassler)\
**Replies:** 49\
**Last updated:** [November 20, 2022, 11:48am UTC](https://discourse.julialang.org/t/atom-1-39-wont-build-julia-client/26696 "2022-11-20T11:48:22Z")

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Atom auto-updated from 1.38 to 1.39 this morning. When I started it, it sent me a message saying a needed to rebuild some out-of-date packages. I followed the prompt to rebuild, but it failed (sorry, I didn’t save the ex…

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## [Llvm code excess line?](https://discourse.julialang.org/t/llvm-code-excess-line/90532)

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**Author:** [@andrey2185](https://discourse.julialang.org/u/andrey2185)\
**Replies:** 2\
**Last updated:** [November 20, 2022, 11:22am UTC](https://discourse.julialang.org/t/llvm-code-excess-line/90532 "2022-11-20T11:22:48Z")

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hello, what is this line for? %3 = and i8 %2, 1 in this: julia\> @code\_llvm true | false define i8 @"julia\_|\_7397"(i8 zeroext %0, i8 zeroext %1) #0 { top: %2 = or i8 %1, %0 %3 = and i8 %2, 1 ret i8 %3 } it is wo…

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## [The relationship between exsting julia objects and gc time?](https://discourse.julialang.org/t/the-relationship-between-exsting-julia-objects-and-gc-time/90533)

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**Author:** [@Brian1](https://discourse.julialang.org/u/Brian1)\
**Replies:** 1\
**Last updated:** [November 20, 2022, 11:01am UTC](https://discourse.julialang.org/t/the-relationship-between-exsting-julia-objects-and-gc-time/90533 "2022-11-20T11:01:54Z")

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I found that, with more and more large objects generated in running time, the gc time will increase massively. So I have to always pay much attention on generating objects. Is there a way I can handle this properly?

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## [Can I reconstruct a network using Flux.params in Flux.jl?](https://discourse.julialang.org/t/can-i-reconstruct-a-network-using-flux-params-in-flux-jl/90531)

<div class="topic-metadata">

**Author:** [@iHany](https://discourse.julialang.org/u/iHany)\
**Replies:** 2\
**Last updated:** [November 20, 2022, 9:31am UTC](https://discourse.julialang.org/t/can-i-reconstruct-a-network-using-flux-params-in-flux-jl/90531 "2022-11-20T09:31:04Z")

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Hi, I have a custom network nn. I can get the parameters p of nn by p = Flux.params(nn). Now, I’d like to reconstruct a neural network from the parameters. Is there any some ways to do the following? nn = NN() # con…

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## [Using views with CartesianIndices: Is this a bug?](https://discourse.julialang.org/t/using-views-with-cartesianindices-is-this-a-bug/19823)

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**Author:** [@Sean\_McBane](https://discourse.julialang.org/u/Sean_McBane)\
**Replies:** 3\
**Last updated:** [November 20, 2022, 8:01am UTC](https://discourse.julialang.org/t/using-views-with-cartesianindices-is-this-a-bug/19823 "2022-11-20T08:01:56Z")

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I want to do something analogous to the following snippet: function reverse\_first\_dim(A::AbstractArray) B = similar(A) trailing = size(A)\[2:end\] |\> CartesianIndices N = size(A, 1) @views B\[N:-1:1, traili…

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## [Renaming multiple columns in Julia DataFrames](https://discourse.julialang.org/t/renaming-multiple-columns-in-julia-dataframes/83072)

<div class="topic-metadata">

**Author:** [@mbah](https://discourse.julialang.org/u/mbah)\
**Replies:** 7\
**Last updated:** [November 20, 2022, 5:40am UTC](https://discourse.julialang.org/t/renaming-multiple-columns-in-julia-dataframes/83072 "2022-11-20T05:40:35Z")

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I have the following Julia Dataframe; data\_test = DataFrame(Time = 1:2, X1 = \[0,1\], X2 = \[10,5\]) And I have a list of names as follows; technology = \["oil", "gas"\] How do I rename columns X1 and X2 using the list (ex…

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## [Plots Broken on MacOS Ventura](https://discourse.julialang.org/t/plots-broken-on-macos-ventura/89386)

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**Author:** [@liamfdoherty](https://discourse.julialang.org/u/liamfdoherty)\
**Replies:** 17\
**Last updated:** [November 20, 2022, 1:57am UTC](https://discourse.julialang.org/t/plots-broken-on-macos-ventura/89386 "2022-11-20T01:57:55Z")

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I just upgraded to MacOS Ventura (13.0), and now, when I try to do a basic plot, e.g., with using Plots xvals = LinRange(0, 1, 100) f(x) = x^2 plot(xvals, f.(xvals)) I get the following error: Error showing value of t…

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