# Latest

**URL:** https://discourse.julialang.org/latest.md?page=475

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

**Page:** 476

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## [Inconsistent CPU utilisation in @threads loops](https://discourse.julialang.org/t/inconsistent-cpu-utilisation-in-threads-loops/110512)

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**Author:** [@ysh](https://discourse.julialang.org/u/ysh)\
**Replies:** 20\
**Last updated:** [February 23, 2024, 8:55pm UTC](https://discourse.julialang.org/t/inconsistent-cpu-utilisation-in-threads-loops/110512 "2024-02-23T20:55:43Z")

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Consider a MWE where some moderately-heavy calculations are performed in a parallel loop. Here, I am simulating the calculations by doing eigen: using LinearAlgebra, Random BLAS.set\_num\_threads(1) # turn off BLAS parall…

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## [Is JuMP suitable for very big problems?](https://discourse.julialang.org/t/is-jump-suitable-for-very-big-problems/110642)

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**Author:** [@mrys](https://discourse.julialang.org/u/mrys)\
**Replies:** 3\
**Last updated:** [February 23, 2024, 7:24pm UTC](https://discourse.julialang.org/t/is-jump-suitable-for-very-big-problems/110642 "2024-02-23T19:24:41Z")

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This question has certainly been asked, but I couldn’t actually find a clear answer. Having the following problem: n = 10000; k = rand(n, n) ke = 0.5(k + k'); function func(x::T...) where T y = collect(x) retur…

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## [Running mulitple SQL Scripts](https://discourse.julialang.org/t/running-mulitple-sql-scripts/110652)

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**Author:** [@jjAtNxtPt](https://discourse.julialang.org/u/jjAtNxtPt)\
**Replies:** 13\
**Last updated:** [February 23, 2024, 7:17pm UTC](https://discourse.julialang.org/t/running-mulitple-sql-scripts/110652 "2024-02-23T19:17:57Z")

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Hi, all. New to Julia and trying to set up a way to run queries on SQL Server and store results into a DuckDB. I’ve got the basic program down that reads all of the SQL files from a directory, running each one in turn,…

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## [Julia cloud app design](https://discourse.julialang.org/t/julia-cloud-app-design/105030)

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**Author:** [@monty](https://discourse.julialang.org/u/monty)\
**Replies:** 2\
**Last updated:** [February 23, 2024, 7:11pm UTC](https://discourse.julialang.org/t/julia-cloud-app-design/105030 "2024-02-23T19:11:10Z")

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Our company (EnviTrace; https://envitrace.com) is seeking a quote for contract support to design Julia software and interactive web/mobile applications. The software will be deployed on the cloud. Interactive visualizat…

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## [How do I create a Makie recipe with keyword-argument?](https://discourse.julialang.org/t/how-do-i-create-a-makie-recipe-with-keyword-argument/110641)

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**Author:** [@Larbino1](https://discourse.julialang.org/u/Larbino1)\
**Replies:** 3\
**Last updated:** [February 23, 2024, 4:36pm UTC](https://discourse.julialang.org/t/how-do-i-create-a-makie-recipe-with-keyword-argument/110641 "2024-02-23T16:36:57Z")

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Let me explain my case: I want to create a plotting function that plots a 3D transformation by drawing x-y-z axes relative to the origin. I’m not decided whether or not to use scatter or give it a custom name like plot…

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## [How to connect MTK thermal Heatport?](https://discourse.julialang.org/t/how-to-connect-mtk-thermal-heatport/110586)

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**Author:** [@Zhijian](https://discourse.julialang.org/u/Zhijian)\
**Replies:** 4\
**Last updated:** [February 23, 2024, 4:35pm UTC](https://discourse.julialang.org/t/how-to-connect-mtk-thermal-heatport/110586 "2024-02-23T16:35:12Z")

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Hi guys, I am new to Julia and am using ModelingToolkit to try to build a simple heat conduction model (3R2C wall model). So it will look like this… I am trying to create a constant ambient temperature then switch t…

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## [Line caps and joins in Plots](https://discourse.julialang.org/t/line-caps-and-joins-in-plots/39826)

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**Author:** [@sgaure](https://discourse.julialang.org/u/sgaure)\
**Replies:** 2\
**Last updated:** [February 23, 2024, 4:28pm UTC](https://discourse.julialang.org/t/line-caps-and-joins-in-plots/39826 "2024-02-23T16:28:48Z")

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I have looked around in the Plots package and am unable to find out how to set the line cap style, and line join style. A simple example is this: using Plots pyplot() plot(\[0 0.5; 0.5 1\], \[1 1; 1 1\], linewidth=10) That…

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## [Help with Flux.jl, Metal.jl (Apple Silicon) and Conv layers](https://discourse.julialang.org/t/help-with-flux-jl-metal-jl-apple-silicon-and-conv-layers/105632)

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**Author:** [@JakobPeterlin](https://discourse.julialang.org/u/JakobPeterlin)\
**Replies:** 2\
**Last updated:** [February 23, 2024, 4:27pm UTC](https://discourse.julialang.org/t/help-with-flux-jl-metal-jl-apple-silicon-and-conv-layers/105632 "2024-02-23T16:27:15Z")

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Hello, after trying to use Flux.jl to reimplement some PyTorch code (SpinalVGG), I encountered some difficulties when trying to run my code on an M2 Max’s GPU with Metal.jl. The error boils down to the following code, w…

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## [Arrows in plots](https://discourse.julialang.org/t/arrows-in-plots/110629)

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**Author:** [@blob](https://discourse.julialang.org/u/blob)\
**Replies:** 1\
**Last updated:** [February 23, 2024, 3:50pm UTC](https://discourse.julialang.org/t/arrows-in-plots/110629 "2024-02-23T15:50:29Z")

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I want to plot lines with arrows at the end of the lines. Following this thread, I got: obtained from: Using Plots plot(\[0.0 1.0\]',\[0.0 -0.71\]',label="Correct, solid blue with arrow",palette=:imola100,lw=2,arrow=tr…

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## [How to create an HTML questionnaire that is driven by Julia in the background?](https://discourse.julialang.org/t/how-to-create-an-html-questionnaire-that-is-driven-by-julia-in-the-background/110644)

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**Author:** [@WuSiren](https://discourse.julialang.org/u/WuSiren)\
**Replies:** 2\
**Last updated:** [February 23, 2024, 3:41pm UTC](https://discourse.julialang.org/t/how-to-create-an-html-questionnaire-that-is-driven-by-julia-in-the-background/110644 "2024-02-23T15:41:01Z")

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I want to point a site to an HTML file (using Nginx), which is a questionnaire. For example, people who open the page are asked to fill in a number randomly and click Submit button. Julia records the number each person f…

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## [Fast solution of a two-point boundary value problem with Shooting](https://discourse.julialang.org/t/fast-solution-of-a-two-point-boundary-value-problem-with-shooting/110531)

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**Author:** [@flibe](https://discourse.julialang.org/u/flibe)\
**Replies:** 1\
**Last updated:** [February 23, 2024, 3:01pm UTC](https://discourse.julialang.org/t/fast-solution-of-a-two-point-boundary-value-problem-with-shooting/110531 "2024-02-23T15:01:05Z")

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Dear All, I am trying to find a way to solve as fast as possible a two point boundary value problem (TPBVP) related to the optimal control of a storage system (it arises from the associated optimality necessary conditio…

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## [Is there a way to look for all non-ascii unicode symbols in my project?](https://discourse.julialang.org/t/is-there-a-way-to-look-for-all-non-ascii-unicode-symbols-in-my-project/110647)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 2\
**Last updated:** [February 23, 2024, 2:56pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-look-for-all-non-ascii-unicode-symbols-in-my-project/110647 "2024-02-23T14:56:14Z")

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I want to check the usage of Unicode symbols on my package (like β, η…), is there any way to use the search project in VSCode for Unicode non-ascii symbols ?

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## [Why is this simple function allocating?](https://discourse.julialang.org/t/why-is-this-simple-function-allocating/110646)

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**Author:** [@Abhimanyu\_Susobhanan](https://discourse.julialang.org/u/Abhimanyu_Susobhanan)\
**Replies:** 4\
**Last updated:** [February 23, 2024, 2:29pm UTC](https://discourse.julialang.org/t/why-is-this-simple-function-allocating/110646 "2024-02-23T14:29:39Z")

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I have a simple struct and a corresponding oneunit method. I find that the oneunit function allocates memory when I use it on my struct. How can I avoid this behavior? using BenchmarkTools import Base.oneunit struct My…

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## [ERROR: TaskFailedException](https://discourse.julialang.org/t/error-taskfailedexception/110630)

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**Author:** [@Sahil\_Khan](https://discourse.julialang.org/u/Sahil_Khan)\
**Replies:** 1\
**Last updated:** [February 23, 2024, 1:51pm UTC](https://discourse.julialang.org/t/error-taskfailedexception/110630 "2024-02-23T13:51:45Z")

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I have a differential equation based model for which i’m doing inference using Turing. For solver I use alg = Rodas5P(linsolve = QRFactorization()). I was wondering if QRFactorization has anything to do with current err…

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## [Which matrix multiplication is more efficient? A\*B and C\*B or \[A; C\]\*B](https://discourse.julialang.org/t/which-matrix-multiplication-is-more-efficient-a-b-and-c-b-or-a-c-b/110636)

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**Author:** [@MatheusJanczkowski](https://discourse.julialang.org/u/MatheusJanczkowski)\
**Replies:** 9\
**Last updated:** [February 23, 2024, 1:07pm UTC](https://discourse.julialang.org/t/which-matrix-multiplication-is-more-efficient-a-b-and-c-b-or-a-c-b/110636 "2024-02-23T13:07:25Z")

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I have pairs of square matrix multiplications which share one of the matrices, for example: AB, CB, where A, B and C are real square matrices. My question is: is it more efficient to compute both multiplications separ…

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## [Unit testing with generated code](https://discourse.julialang.org/t/unit-testing-with-generated-code/110614)

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**Author:** [@mike.ingold](https://discourse.julialang.org/u/mike.ingold)\
**Replies:** 8\
**Last updated:** [February 23, 2024, 1:02pm UTC](https://discourse.julialang.org/t/unit-testing-with-generated-code/110614 "2024-02-23T13:02:04Z")

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Problem Statement: I have a package where a number of functions are defined with multiple-dispatch signatures like f(x::A, y::B). Say that methods may be implemented for m types A and n types B and there are p functions,…

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## [Fail to install FerriteViz package](https://discourse.julialang.org/t/fail-to-install-ferriteviz-package/110639)

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**Author:** [@Hieu\_Huynh](https://discourse.julialang.org/u/Hieu_Huynh)\
**Replies:** 0\
**Last updated:** [February 23, 2024, 12:52pm UTC](https://discourse.julialang.org/t/fail-to-install-ferriteviz-package/110639 "2024-02-23T12:52:38Z")

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Hello I’m new with Julia and trying to install the FerriteViz package. Almost everything is installed except for MathTexengine, Makie, and FerriteViz isn’t. When i tried to look for the error using julia\> err, it show P…

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## [Skipping a lot of lines in CSV.read() allocates too much memory](https://discourse.julialang.org/t/skipping-a-lot-of-lines-in-csv-read-allocates-too-much-memory/110121)

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**Author:** [@aris](https://discourse.julialang.org/u/aris)\
**Replies:** 77\
**Last updated:** [February 23, 2024, 11:30am UTC](https://discourse.julialang.org/t/skipping-a-lot-of-lines-in-csv-read-allocates-too-much-memory/110121 "2024-02-23T11:30:30Z")

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Hello everyone, Consider the following example: using CSV, DataFrames number\_of\_lines = 10^4 CSV.write("data.csv", DataFrame(rand(number\_of\_lines,10), :auto)) steps = 20 chunk = round(Int,number\_of\_lines/steps) for …

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## [Loading data sometimes very slow on HPC system](https://discourse.julialang.org/t/loading-data-sometimes-very-slow-on-hpc-system/110563)

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**Author:** [@fgerick](https://discourse.julialang.org/u/fgerick)\
**Replies:** 24\
**Last updated:** [February 23, 2024, 11:19am UTC](https://discourse.julialang.org/t/loading-data-sometimes-very-slow-on-hpc-system/110563 "2024-02-23T11:19:13Z")

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Hi there, I am processing a bunch of JLD2 files (O(10GB)) on my local cluster. Sometimes (not always), loading a file takes ages (\>10min), but sometimes it only takes ~10 seconds. Usually after loading it slowly once, t…

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## [Cast Polygon to Multipolygon with ArchGDAL.jl](https://discourse.julialang.org/t/cast-polygon-to-multipolygon-with-archgdal-jl/110592)

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**Author:** [@Jakob](https://discourse.julialang.org/u/Jakob)\
**Replies:** 2\
**Last updated:** [February 23, 2024, 8:32am UTC](https://discourse.julialang.org/t/cast-polygon-to-multipolygon-with-archgdal-jl/110592 "2024-02-23T08:32:31Z")

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I have a Vector{IGeometry{wkbMultiPolygon}} which I need to simplify for plotting. However, doing ArchGDAL.simplify.(geoms, 0.001) results in some wkbMultiPolygons becoming wkbPolygons and Makie is not happy about the h…

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## [Supporting syntax \`x not in y\` as alias for \`!(x in y)\`](https://discourse.julialang.org/t/supporting-syntax-x-not-in-y-as-alias-for-x-in-y/110146)

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**Author:** [@fingolfin](https://discourse.julialang.org/u/fingolfin)\
**Replies:** 48\
**Last updated:** [February 23, 2024, 7:01am UTC](https://discourse.julialang.org/t/supporting-syntax-x-not-in-y-as-alias-for-x-in-y/110146 "2024-02-23T07:01:17Z")

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One thing I like in Python is that they allow writing x not in y instead of !(x in y). To me this results in code that is much easier to read (obviously this is subjective). I wonder if it would be possible to support t…

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## [Is the warning about \`@assert\` or \`AssertionError\`?](https://discourse.julialang.org/t/is-the-warning-about-assert-or-assertionerror/110613)

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**Author:** [@sadish-d](https://discourse.julialang.org/u/sadish-d)\
**Replies:** 7\
**Last updated:** [February 23, 2024, 3:22am UTC](https://discourse.julialang.org/t/is-the-warning-about-assert-or-assertionerror/110613 "2024-02-23T03:22:10Z")

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I use the @assert macro all over the place, including inside struct constructors to make sure my types are following the restrictions they’re supposed to. The documentation on @assert says it is the preferred syntax for…

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## [Yolov9 example in Julia](https://discourse.julialang.org/t/yolov9-example-in-julia/110619)

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**Author:** [@Jose\_Diaz](https://discourse.julialang.org/u/Jose_Diaz)\
**Replies:** 0\
**Last updated:** [February 23, 2024, 2:03am UTC](https://discourse.julialang.org/t/yolov9-example-in-julia/110619 "2024-02-23T02:03:44Z")

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I wrote a tiny example, it’s not perfect but it can give an idea on how to use this model with onnxruntime in Julia

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## [Problems performing 1D-FDTD for dispersive dielectric uisng lorentz model in Julia](https://discourse.julialang.org/t/problems-performing-1d-fdtd-for-dispersive-dielectric-uisng-lorentz-model-in-julia/110617)

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**Author:** [@geoselenicmonkey](https://discourse.julialang.org/u/geoselenicmonkey)\
**Replies:** 0\
**Last updated:** [February 23, 2024, 1:34am UTC](https://discourse.julialang.org/t/problems-performing-1d-fdtd-for-dispersive-dielectric-uisng-lorentz-model-in-julia/110617 "2024-02-23T01:34:15Z")

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So I am trying to model a dispersive dielectric using the Lorentz model in Julia, more specifically I am trying to obtain the frequency-dependent reflectivity of the material. I am ultimately trying to replicate the resu…

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## [Zero-dimensional array interface for custom type](https://discourse.julialang.org/t/zero-dimensional-array-interface-for-custom-type/110609)

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**Author:** [@sadish-d](https://discourse.julialang.org/u/sadish-d)\
**Replies:** 1\
**Last updated:** [February 23, 2024, 1:25am UTC](https://discourse.julialang.org/t/zero-dimensional-array-interface-for-custom-type/110609 "2024-02-23T01:25:49Z")

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I have struct S the\_only\_field end For my struct to hold data, I need it to have a field, and that means I need the field to have a name. But I would like to use it without having to define something like the\_only\_fiel…

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## [Using a module defined in REPL](https://discourse.julialang.org/t/using-a-module-defined-in-repl/110611)

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**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 2\
**Last updated:** [February 23, 2024, 1:14am UTC](https://discourse.julialang.org/t/using-a-module-defined-in-repl/110611 "2024-02-23T01:14:44Z")

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julia\> module A a = 1 b = 2 end Main.A julia\> a ERROR: UndefVarError: \`a\` not defined julia\> A.a 1 julia\> A.b 2 julia\> using A ERROR: ArgumentError: Package A not found in current path, maybe you…

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## [With or without module prefix?](https://discourse.julialang.org/t/with-or-without-module-prefix/110612)

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**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 3\
**Last updated:** [February 23, 2024, 12:25am UTC](https://discourse.julialang.org/t/with-or-without-module-prefix/110612 "2024-02-23T00:25:09Z")

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I see codes like using Plots x = range(0, 2π; length = 100) y = sin.(x) plot(x, y) and also codes like julia\> using Random julia\> using Random: seed! julia\> seed!(1234); julia\> rand(2) 2-element Vector{Float64}:…

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## [Suppress Error message and draw another random numbs during simulation](https://discourse.julialang.org/t/suppress-error-message-and-draw-another-random-numbs-during-simulation/110555)

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**Author:** [@Wooheon](https://discourse.julialang.org/u/Wooheon)\
**Replies:** 6\
**Last updated:** [February 23, 2024, 12:08am UTC](https://discourse.julialang.org/t/suppress-error-message-and-draw-another-random-numbs-during-simulation/110555 "2024-02-23T00:08:50Z")

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Hi, I am trying to calculate the bias and mean squared errors, which need repetition of simulations. The problem is my optimize result sometimes gives an error message of AssertionError: isfinite(phi\_c) && isfinite(dp…

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## [Bwareaopen in Julia?](https://discourse.julialang.org/t/bwareaopen-in-julia/110603)

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**Author:** [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Replies:** 4\
**Last updated:** [February 22, 2024, 11:04pm UTC](https://discourse.julialang.org/t/bwareaopen-in-julia/110603 "2024-02-22T23:04:14Z")

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Hi, I’ve searched (basically, googled it) but could not find one, thought I’m convinced that id does exist. Anyone knows how to do what Matlab’s bwareaopen does? Thanks.

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## [Alternative to multivariatestats.jl](https://discourse.julialang.org/t/alternative-to-multivariatestats-jl/110540)

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**Author:** [@jcbritobr](https://discourse.julialang.org/u/jcbritobr)\
**Replies:** 6\
**Last updated:** [February 22, 2024, 9:45pm UTC](https://discourse.julialang.org/t/alternative-to-multivariatestats-jl/110540 "2024-02-22T21:45:13Z")

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Hello, good evening. There are alternatives to multivariatestats.jl?

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