# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1212

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

**Page:** 1213

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## [New package LaurentPolynomials](https://discourse.julialang.org/t/new-package-laurentpolynomials/70947)

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**Author:** [@Jean\_Michel](https://discourse.julialang.org/u/Jean_Michel)\
**Replies:** 5\
**Last updated:** [November 9, 2021, 6:36pm UTC](https://discourse.julialang.org/t/new-package-laurentpolynomials/70947 "2021-11-09T18:36:08Z")

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I want to announce two packages which go together, one for univariate and the other for multivariate polynomials. The first one is LaurentPolynomials I wanted to call this package Pols, since this is the name of the…

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## [Parallel computing on M1 Max?](https://discourse.julialang.org/t/parallel-computing-on-m1-max/70343)

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**Author:** [@ChunXi\_Zhang](https://discourse.julialang.org/u/ChunXi_Zhang)\
**Replies:** 6\
**Last updated:** [November 9, 2021, 6:22pm UTC](https://discourse.julialang.org/t/parallel-computing-on-m1-max/70343 "2021-11-09T18:22:22Z")

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With the release of 2021 macbook pro with M1 Pro/Max, I’m wondering if there is a good API/Libs for doing parallel computing on that chip? From the reviews, the computational power of that device is insane, sometimes on…

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## [How to actually replace OO structures in Julia?](https://discourse.julialang.org/t/how-to-actually-replace-oo-structures-in-julia/71198)

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**Author:** [@Bardo](https://discourse.julialang.org/u/Bardo)\
**Replies:** 5\
**Last updated:** [November 9, 2021, 5:35pm UTC](https://discourse.julialang.org/t/how-to-actually-replace-oo-structures-in-julia/71198 "2021-11-09T17:35:03Z")

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Hi, I need your help with the following common task which, when described using classes looks like below. We start with a reference or idealized model. Later, the model is going to be refined, properties and methods g…

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## [How to unfold plots](https://discourse.julialang.org/t/how-to-unfold-plots/71196)

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**Author:** [@corny85](https://discourse.julialang.org/u/corny85)\
**Replies:** 6\
**Last updated:** [November 9, 2021, 4:24pm UTC](https://discourse.julialang.org/t/how-to-unfold-plots/71196 "2021-11-09T16:24:55Z")

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Hello, I want to unfold a vector of plots but i don’t know how to do it. using Plots p = \[plot(a\[i\]\[1:end,2\],a\[i\]\[1:end,1\]) for i =1:5\] plot(p) It doesn’t work. Thanks for your help

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## [Why using JLD2 leads to LoadError: too many parameters for type in VS code?](https://discourse.julialang.org/t/why-using-jld2-leads-to-loaderror-too-many-parameters-for-type-in-vs-code/71169)

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**Author:** [@Amro](https://discourse.julialang.org/u/Amro)\
**Replies:** 4\
**Last updated:** [November 9, 2021, 2:43pm UTC](https://discourse.julialang.org/t/why-using-jld2-leads-to-loaderror-too-many-parameters-for-type-in-vs-code/71169 "2021-11-09T14:43:26Z")

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@simonster @lhupe @staticfloat @ararslan @tim.holy @giordano @jeff.bezanson @gdkrmr @JonasIsensee I am working on VS code with julia v1.4.3 extension. When I call the using JLD2, I have the bellow error. However…

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## [\[ANN\] I started a package for writing CAD design in Julia](https://discourse.julialang.org/t/ann-i-started-a-package-for-writing-cad-design-in-julia/53299)

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**Author:** [@circonflexe](https://discourse.julialang.org/u/circonflexe)\
**Replies:** 12\
**Last updated:** [November 9, 2021, 6:52am UTC](https://discourse.julialang.org/t/ann-i-started-a-package-for-writing-cad-design-in-julia/53299 "2021-11-09T06:52:22Z")

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As the title says, I started writing a package for defining CAD objects in Julia. Why would this be useful? I believe it is useful to have an alternative to OpenSCAD which offers all the advantages of a full-fledged pr…

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## [Reducing allocations when subtracting vectors and multiplying by scalars](https://discourse.julialang.org/t/reducing-allocations-when-subtracting-vectors-and-multiplying-by-scalars/71203)

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**Author:** [@jewh](https://discourse.julialang.org/u/jewh)\
**Replies:** 9\
**Last updated:** [November 9, 2021, 1:32pm UTC](https://discourse.julialang.org/t/reducing-allocations-when-subtracting-vectors-and-multiplying-by-scalars/71203 "2021-11-09T13:32:34Z")

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Is it possible to re-write the following function foo(x, y), such that it only uses one allocation? using BenchmarkTools function foo(x::Vector{Float64}, y::Vector{Float64}) (x .- y) .\* 3.0 end This currently yie…

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## [Error "Julia package not part of current environment"](https://discourse.julialang.org/t/error-julia-package-not-part-of-current-environment/42903)

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**Author:** [@Juan](https://discourse.julialang.org/u/Juan)\
**Replies:** 2\
**Last updated:** [November 9, 2021, 12:37pm UTC](https://discourse.julialang.org/t/error-julia-package-not-part-of-current-environment/42903 "2021-11-09T12:37:38Z")

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Hello. When I start VS Code (with Julia 1.5 and extension julia-vscode 0.17.2 and some olders too) I get this error: You opened a julia package that is not part of your current environment. Do you want to activate a …

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## [Unitful and automatic differentiation?](https://discourse.julialang.org/t/unitful-and-automatic-differentiation/71145)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 18\
**Last updated:** [November 9, 2021, 11:41am UTC](https://discourse.julialang.org/t/unitful-and-automatic-differentiation/71145 "2021-11-09T11:41:55Z")

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Automatic differentiation (at least with ForwarDiff) does not support Unitful quantitites: julia\> using Unitful, ForwardDiff julia\> f(x) = x^2 f (generic function with 1 method) julia\> x = 2.0u"nm" 2.0 nm julia\> Forw…

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## [\[cluster\] Understanding parallel performance. Is GC triggered too early?](https://discourse.julialang.org/t/cluster-understanding-parallel-performance-is-gc-triggered-too-early/71197)

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**Author:** [@carlo](https://discourse.julialang.org/u/carlo)\
**Replies:** 0\
**Last updated:** [November 9, 2021, 9:42am UTC](https://discourse.julialang.org/t/cluster-understanding-parallel-performance-is-gc-triggered-too-early/71197 "2021-11-09T09:42:15Z")

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Good morning, everyone! After weeks of lurking in the forum to fix other of my problems (thanks, it’s a precious resource) I decided to go on and ask my own particular question. I am facing the following problem: I am …

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## [\`convert\` is ambiguous](https://discourse.julialang.org/t/convert-is-ambiguous/71192)

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**Author:** [@goerch](https://discourse.julialang.org/u/goerch)\
**Replies:** 1\
**Last updated:** [November 9, 2021, 8:57am UTC](https://discourse.julialang.org/t/convert-is-ambiguous/71192 "2021-11-09T08:57:57Z")

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Surprising for me (Julia 1.6.3): julia\> a = \[nothing\] 1-element Vector{Nothing}: nothing julia\> a\[1\] = (0,) ERROR: MethodError: convert(::Type{Union{}}, ::Tuple{Int64}) is ambiguous. Candidates: convert(::Type{T}, x…

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## [Issue with plots in vscode](https://discourse.julialang.org/t/issue-with-plots-in-vscode/71158)

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**Author:** [@bww00](https://discourse.julialang.org/u/bww00)\
**Replies:** 3\
**Last updated:** [November 9, 2021, 8:50am UTC](https://discourse.julialang.org/t/issue-with-plots-in-vscode/71158 "2021-11-09T08:50:50Z")

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in a command window the following produces a plot (2 messages). Run in vscode doesnt produc a plot. julia\> using Plots (process:23960): GLib-GIO-WARNING \*\*: 09:56:57.906: Unexpectedly, UWP app Microsoft.Office.OneNote…

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## [Gadfly can't do Time values?](https://discourse.julialang.org/t/gadfly-cant-do-time-values/71187)

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**Author:** [@luc-j-bourhis](https://discourse.julialang.org/u/luc-j-bourhis)\
**Replies:** 0\
**Last updated:** [November 9, 2021, 8:20am UTC](https://discourse.julialang.org/t/gadfly-cant-do-time-values/71187 "2021-11-09T08:20:13Z")

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It seems that Gadly cannot handle Time on the x-axis (from Dates) as shown below. Would there be a package that could plug that hole? Or do I have to use Period instead as suggested by the error message? Or am I missing …

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## [DataFrames : Removing values from column](https://discourse.julialang.org/t/dataframes-removing-values-from-column/71153)

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**Author:** [@jnewbie](https://discourse.julialang.org/u/jnewbie)\
**Replies:** 3\
**Last updated:** [November 9, 2021, 8:09am UTC](https://discourse.julialang.org/t/dataframes-removing-values-from-column/71153 "2021-11-09T08:09:56Z")

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Hey everyone, I would like to remove values that are equal to datetime2unix(DateTime(0)) from my column : replace!(df\[:,:col2\], datetime2unix(DateTime(0)) =\> nothing) OR df\[:,:col2\] = replace(df\[:,:col2\], datetime2un…

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## [I want to replicate with Named Tuples what I do with Dictionaries but I can't](https://discourse.julialang.org/t/i-want-to-replicate-with-named-tuples-what-i-do-with-dictionaries-but-i-cant/70522)

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**Author:** [@Soldalma](https://discourse.julialang.org/u/Soldalma)\
**Replies:** 9\
**Last updated:** [November 9, 2021, 7:51am UTC](https://discourse.julialang.org/t/i-want-to-replicate-with-named-tuples-what-i-do-with-dictionaries-but-i-cant/70522 "2021-11-09T07:51:48Z")

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I wrote some code that fills an array of dictionaries step by step. I did not use Int64 for the values because in “real life” I do not know the types of the values in advance. my\_dicts = \[Dict{String,Any}() for \_ in 1…

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## [Fastest possible trilinear interpolation with \`Interpolations.jl\`](https://discourse.julialang.org/t/fastest-possible-trilinear-interpolation-with-interpolations-jl/71184)

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**Author:** [@Chiil](https://discourse.julialang.org/u/Chiil)\
**Replies:** 1\
**Last updated:** [November 9, 2021, 7:47am UTC](https://discourse.julialang.org/t/fastest-possible-trilinear-interpolation-with-interpolations-jl/71184 "2021-11-09T07:47:40Z")

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I am working on developing a machine learning application in which two instances of our CFD code work simultaneously at different resolutions and data is passed between the two instances. For this, I need to have fastest…

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## [GalacticOptim with AmplNLWriter optimizer](https://discourse.julialang.org/t/galacticoptim-with-amplnlwriter-optimizer/71137)

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**Author:** [@ver\_kh](https://discourse.julialang.org/u/ver_kh)\
**Replies:** 10\
**Last updated:** [November 9, 2021, 1:33am UTC](https://discourse.julialang.org/t/galacticoptim-with-amplnlwriter-optimizer/71137 "2021-11-09T01:33:43Z")

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Hello! I’m trying to use GalacticOptim.jl with AmplNLWriter.jl optimizer but it’s not working. using GalacticOptim, AmplNLWriter, Ipopt\_jll rosenbrock(x,p) = (p\[1\] - x\[1\])^2 + p\[2\] \* (x\[2\] - x\[1\]^2)^2 x0 = zeros(2) …

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## [\`@everywhere begin ... end\` errors when loading packages (but only once)](https://discourse.julialang.org/t/everywhere-begin-end-errors-when-loading-packages-but-only-once/64774)

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**Author:** [@StevenWhitaker](https://discourse.julialang.org/u/StevenWhitaker)\
**Replies:** 5\
**Last updated:** [November 8, 2021, 11:25pm UTC](https://discourse.julialang.org/t/everywhere-begin-end-errors-when-loading-packages-but-only-once/64774 "2021-11-08T23:25:38Z")

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Consider a directory that contains only the following two files. # one.jl using Distributed addprocs(4 - nprocs() + 1) @everywhere begin using Pkg Pkg.activate(".") using MAT end println("done") # two.jl …

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## [\[ANN\] Trixi.jl v0.4: New features and performance improvements for hyperbolic PDEs](https://discourse.julialang.org/t/ann-trixi-jl-v0-4-new-features-and-performance-improvements-for-hyperbolic-pdes/69995)

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**Author:** [@ranocha](https://discourse.julialang.org/u/ranocha)\
**Replies:** 15\
**Last updated:** [November 8, 2021, 9:53pm UTC](https://discourse.julialang.org/t/ann-trixi-jl-v0-4-new-features-and-performance-improvements-for-hyperbolic-pdes/69995 "2021-11-08T21:53:01Z")

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We are pleased to announce the release of v0.4 of Trixi.jl, our Julia package providing adaptive high-order numerical simulations of hyperbolic PDEs. Compared to the initial release of v0.3, we have introduced a ton of n…

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## [LoadError: UndefVarError: @variables not defined](https://discourse.julialang.org/t/loaderror-undefvarerror-variables-not-defined/71170)

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**Author:** [@GoH](https://discourse.julialang.org/u/GoH)\
**Replies:** 2\
**Last updated:** [November 8, 2021, 9:24pm UTC](https://discourse.julialang.org/t/loaderror-undefvarerror-variables-not-defined/71170 "2021-11-08T21:24:08Z")

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I got the error ‘LoadError: UndefVarError: @variables not defined’ while testing the code provided by ModelingToolkits webpage Solving Nonlinear Systems with NLsolve · ModelingToolkit.jl Here is the code: begin using …

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## [Different ways to calculate rowwise sums?](https://discourse.julialang.org/t/different-ways-to-calculate-rowwise-sums/71026)

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**Author:** [@Juan](https://discourse.julialang.org/u/Juan)\
**Replies:** 7\
**Last updated:** [November 8, 2021, 8:52pm UTC](https://discourse.julialang.org/t/different-ways-to-calculate-rowwise-sums/71026 "2021-11-08T20:52:55Z")

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Random.seed!(1234); df = DataFrame(randn(10, 4), :auto); Row │ x1 x2 x3 ────┼────────────────────────────────── 1 │ 0.867347 2.21188 -0.560501 2 │ -0.901744 0.532813 -0.0192918 3 │ -0.…

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## [How to choose a file by open\_dialog prompt?](https://discourse.julialang.org/t/how-to-choose-a-file-by-open-dialog-prompt/71157)

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**Author:** [@Amro](https://discourse.julialang.org/u/Amro)\
**Replies:** 9\
**Last updated:** [November 8, 2021, 8:27pm UTC](https://discourse.julialang.org/t/how-to-choose-a-file-by-open-dialog-prompt/71157 "2021-11-08T20:27:23Z")

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I am trying to select a file by using open\_dialog() instead of defining the path of the file. However, after the prompt window is opened and I navigate to the file, I cannot really select it and the prompt window is not …

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## [Does DecisionTreeClassifier support missing data in the predictors?](https://discourse.julialang.org/t/does-decisiontreeclassifier-support-missing-data-in-the-predictors/71013)

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**Author:** [@Rahul](https://discourse.julialang.org/u/Rahul)\
**Replies:** 3\
**Last updated:** [November 8, 2021, 8:26pm UTC](https://discourse.julialang.org/t/does-decisiontreeclassifier-support-missing-data-in-the-predictors/71013 "2021-11-08T20:26:43Z")

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I cannot pass missing data to train DecisionTreeClassifier in MLJ. Is this not supported? Although the machine function gave me a warning, I tried to run fit! and it threw and error that the scitype of X isn’t supported. …

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## [\[ANN\] GraphNeuralNetworks.jl](https://discourse.julialang.org/t/ann-graphneuralnetworks-jl/71129)

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**Author:** [@CarloLucibello](https://discourse.julialang.org/u/CarloLucibello)\
**Replies:** 0\
**Last updated:** [November 8, 2021, 8:12am UTC](https://discourse.julialang.org/t/ann-graphneuralnetworks-jl/71129 "2021-11-08T08:12:33Z")

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I am happy to announce GraphNeuralNetworks.jl (GNN.jl in short), a graph neural network library written in Julia and based on the deep learning framework Flux.jl. I have been working on it for the past few months and put…

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## [Closures: pass by value or reference?](https://discourse.julialang.org/t/closures-pass-by-value-or-reference/71155)

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**Author:** [@Bardo](https://discourse.julialang.org/u/Bardo)\
**Replies:** 9\
**Last updated:** [November 8, 2021, 7:13pm UTC](https://discourse.julialang.org/t/closures-pass-by-value-or-reference/71155 "2021-11-08T19:13:49Z")

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Is the following true? “When copied inside a function, variables become local and functions become closures.” (unknown) What causes then the different behavior below? solver(f,x) = f(x) a, b, c = 1, 2, 3; g(x) = a\*x…

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## [Problem in expressing the nonlinear objective](https://discourse.julialang.org/t/problem-in-expressing-the-nonlinear-objective/71127)

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**Author:** [@FH96](https://discourse.julialang.org/u/FH96)\
**Replies:** 3\
**Last updated:** [November 8, 2021, 5:50pm UTC](https://discourse.julialang.org/t/problem-in-expressing-the-nonlinear-objective/71127 "2021-11-08T17:50:48Z")

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Hi, I’m trying to express the NLobjective of a problem which is something like this : sum((A\*v\_j -v\_exp)^2) (A is a matrix) I tried different forms and I got error in each case #@NLobjective(model,Min,sum((dot(module\_f…

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## [How to add unicode special character in Julia](https://discourse.julialang.org/t/how-to-add-unicode-special-character-in-julia/71023)

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**Author:** [@leon](https://discourse.julialang.org/u/leon)\
**Replies:** 17\
**Last updated:** [November 8, 2021, 5:37pm UTC](https://discourse.julialang.org/t/how-to-add-unicode-special-character-in-julia/71023 "2021-11-08T17:37:44Z")

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I’m able to find this list: Unicode Input · The Julia Language. In Matlab, if I want to draw something in a figure like “μmol”, all you need to do is to code it this way: “\\mumol”. I tried to do the same thing in Julia…

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## [Excessive memory consumption when using powermod() with BigInt](https://discourse.julialang.org/t/excessive-memory-consumption-when-using-powermod-with-bigint/71163)

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**Author:** [@rbngz](https://discourse.julialang.org/u/rbngz)\
**Replies:** 2\
**Last updated:** [November 8, 2021, 5:24pm UTC](https://discourse.julialang.org/t/excessive-memory-consumption-when-using-powermod-with-bigint/71163 "2021-11-08T17:24:15Z")

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I want to brute force an 64-bit RSA encrypted text using a meet-in-the-middle attack (This is for university, nothing malicious). To do this, I essentially created a Julia vector with 2^34 BigInt values and broadcasted …

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## [Label vectors in Plots](https://discourse.julialang.org/t/label-vectors-in-plots/71156)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 2\
**Last updated:** [November 8, 2021, 5:21pm UTC](https://discourse.julialang.org/t/label-vectors-in-plots/71156 "2021-11-08T17:21:56Z")

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Hi all, Is it possible to label vectors in a plot rather than in the legend? Here is an example where I would like to label the vectors A and B. using Plots plot( sqrt.(\[0,.5\]), sqrt.(\[0,.5\]), xlims = (-1.…

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## [No Julia option in packages menu](https://discourse.julialang.org/t/no-julia-option-in-packages-menu/71067)

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**Author:** [@Reddeerpie](https://discourse.julialang.org/u/Reddeerpie)\
**Replies:** 7\
**Last updated:** [November 8, 2021, 4:46pm UTC](https://discourse.julialang.org/t/no-julia-option-in-packages-menu/71067 "2021-11-08T16:46:47Z")

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Hi, I want to open a console , there is no julia option in the packages menu and the hot key option doesn’t work . Any ideas as to what the problem might be ?

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