# Latest

**URL:** https://discourse.julialang.org/latest.md?page=802

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

**Page:** 803

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## [Question on Idiomatic Julia, Traits, and Types](https://discourse.julialang.org/t/question-on-idiomatic-julia-traits-and-types/93484)

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**Author:** [@TI36XPro](https://discourse.julialang.org/u/TI36XPro)\
**Replies:** 6\
**Last updated:** [January 25, 2023, 7:36am UTC](https://discourse.julialang.org/t/question-on-idiomatic-julia-traits-and-types/93484 "2023-01-25T07:36:39Z")

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I’m trying to better learn and understand how to write idiomatic Julia. Please consider the following example. I have a some types defined as follows. abstract type MyAbstractType end Base.@kwdef struct MyStruct\_1D \<:…

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## [Error: Package not found in current path?](https://discourse.julialang.org/t/error-package-not-found-in-current-path/80187)

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**Author:** [@math\_opt](https://discourse.julialang.org/u/math_opt)\
**Replies:** 5\
**Last updated:** [January 25, 2023, 7:19am UTC](https://discourse.julialang.org/t/error-package-not-found-in-current-path/80187 "2023-01-25T07:19:07Z")

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This post concerns the following error: ArgumentError: Package TestPkg not found in current path I started a new project TestPkg and ran into the above error. The steps I followed are as follows: I created a folder w…

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## [About extension support](https://discourse.julialang.org/t/about-extension-support/93462)

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**Author:** [@Rratic](https://discourse.julialang.org/u/Rratic)\
**Replies:** 7\
**Last updated:** [January 25, 2023, 6:48am UTC](https://discourse.julialang.org/t/about-extension-support/93462 "2023-01-25T06:48:06Z")

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I’m developing a Julia package that supports extensions. Currently I need to know: Where should I store extension data locally? Store as artifacts, store in scratchspaces or somewhere else? For the code in extensions, …

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## [How to use Julia 1.9?](https://discourse.julialang.org/t/how-to-use-julia-1-9/92442)

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**Author:** [@jar1](https://discourse.julialang.org/u/jar1)\
**Replies:** 3\
**Last updated:** [January 25, 2023, 4:49am UTC](https://discourse.julialang.org/t/how-to-use-julia-1-9/92442 "2023-01-25T04:49:15Z")

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I heard people use pre-release builds of Julia 1.9 but apparently the language server doesn’t support it. Are people using Julia without language server or what?

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## [Type-inference with two variables that must have the same type](https://discourse.julialang.org/t/type-inference-with-two-variables-that-must-have-the-same-type/93421)

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**Author:** [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Replies:** 13\
**Last updated:** [January 25, 2023, 4:32am UTC](https://discourse.julialang.org/t/type-inference-with-two-variables-that-must-have-the-same-type/93421 "2023-01-25T04:32:31Z")

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julia\> fs() = rand(Bool) ? (1,1) : (1.0, 1.0) fs (generic function with 1 method) julia\> f(fs, i) = fs()\[i\] f (generic function with 1 method) julia\> g(fs) = (f(fs, 1), f(fs, 2)) g (generic function with 1 method) jul…

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## [Add\_bridges](https://discourse.julialang.org/t/add-bridges/93478)

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**Author:** [@Stuart\_Rogers](https://discourse.julialang.org/u/Stuart_Rogers)\
**Replies:** 7\
**Last updated:** [January 25, 2023, 3:49am UTC](https://discourse.julialang.org/t/add-bridges/93478 "2023-01-25T03:49:36Z")

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What is the default value of add\_bridges when a JuMP model is created? Can this be checked via a JuMP call? For a JuMP model m, get\_optimizer\_attribute(m, MOI.add\_bridges()) doesn’t work.

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## [How exactly are Julia Arrays Implemented?](https://discourse.julialang.org/t/how-exactly-are-julia-arrays-implemented/92564)

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**Author:** [@astrobc1](https://discourse.julialang.org/u/astrobc1)\
**Replies:** 9\
**Last updated:** [January 25, 2023, 3:00am UTC](https://discourse.julialang.org/t/how-exactly-are-julia-arrays-implemented/92564 "2023-01-25T03:00:57Z")

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I’m curious how exactly Julia arrays are implemented. julia\> t = Array{Float64, 2} Matrix{Float64} (alias for Array{Float64, 2}) julia\> isabstracttype(t) false julia\> isprimitivetype(t) false julia\> isstructtype(t) t…

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## [Is there any plan to support webP exportation?](https://discourse.julialang.org/t/is-there-any-plan-to-support-webp-exportation/93485)

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**Author:** [@rmsmsgood](https://discourse.julialang.org/u/rmsmsgood)\
**Replies:** 0\
**Last updated:** [January 25, 2023, 2:55am UTC](https://discourse.julialang.org/t/is-there-any-plan-to-support-webp-exportation/93485 "2023-01-25T02:55:47Z")

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https://docs.juliaplots.org/stable/api/#Animations I know webM is supported, and just wonder about webP extension for animated figure.

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## [How to solve PDE that also contain Time Delay DDE terms?](https://discourse.julialang.org/t/how-to-solve-pde-that-also-contain-time-delay-dde-terms/93452)

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**Author:** [@Hassan\_Alam](https://discourse.julialang.org/u/Hassan_Alam)\
**Replies:** 1\
**Last updated:** [January 25, 2023, 2:46am UTC](https://discourse.julialang.org/t/how-to-solve-pde-that-also-contain-time-delay-dde-terms/93452 "2023-01-25T02:46:43Z")

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Hello, I am trying to solve a system of partial differential equations that also contains a time delay part. For DDE, people usually use “DDEProblem” and for PDE people use “ODEProblem”. But, when I am trying to solve my…

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## [Logging error TensorBoardLogger with Flux](https://discourse.julialang.org/t/logging-error-tensorboardlogger-with-flux/93482)

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**Author:** [@tchebycheff](https://discourse.julialang.org/u/tchebycheff)\
**Replies:** 0\
**Last updated:** [January 25, 2023, 2:00am UTC](https://discourse.julialang.org/t/logging-error-tensorboardlogger-with-flux/93482 "2023-01-25T02:00:45Z")

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I have trouble logging Flux training output using TensorBoardLogger. The log file created has the following error message: Error! /Users/xxx/log/events.out.tfevents.xxxxx.local is not UTF-8 encoded Saving disabled See c…

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## [Trouble writing OptimizationFunction for automatic forward differentiation during Parameter Estimation of an ODEProblem](https://discourse.julialang.org/t/trouble-writing-optimizationfunction-for-automatic-forward-differentiation-during-parameter-estimation-of-an-odeproblem/93439)

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**Author:** [@juanmvenegas](https://discourse.julialang.org/u/juanmvenegas)\
**Replies:** 2\
**Last updated:** [January 25, 2023, 12:28am UTC](https://discourse.julialang.org/t/trouble-writing-optimizationfunction-for-automatic-forward-differentiation-during-parameter-estimation-of-an-odeproblem/93439 "2023-01-25T00:28:25Z")

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I am trying to learn Julia for its potential use in parameter estimation. I am interested in estimating kinetic parameters of chemical reactions, which usually involves optimizing reaction parameters with multiple indepe…

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## [Plotting histograms with GADFLY](https://discourse.julialang.org/t/plotting-histograms-with-gadfly/93467)

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**Author:** [@ChrisVL1](https://discourse.julialang.org/u/ChrisVL1)\
**Replies:** 3\
**Last updated:** [January 24, 2023, 11:49pm UTC](https://discourse.julialang.org/t/plotting-histograms-with-gadfly/93467 "2023-01-24T23:49:27Z")

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The “density = true” function is not working on my histogram, how do I fix this? prob1 = result3.u u2 = repeat(reshape(S₀, :, 1), 1, 200) y = predict\_neuralsde(prob1, u2)\[1,:,:\]' y1 = y\[end,:\] m = S₀.\*exp.(r.\*1) y\_sort …

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## [Mysterious memory allocation](https://discourse.julialang.org/t/mysterious-memory-allocation/93431)

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**Author:** [@Ross\_Boylan](https://discourse.julialang.org/u/Ross_Boylan)\
**Replies:** 16\
**Last updated:** [January 24, 2023, 10:34pm UTC](https://discourse.julialang.org/t/mysterious-memory-allocation/93431 "2023-01-24T22:34:49Z")

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Using julia --track-allocation identifies the top hotspots in my code for memory allocation: - function zSQdensity(z::Float64, wa::WorkArea) 0 ev = wa.evaluator 0 dat::DataFrame = wa.dat …

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## [Help with student issue: GR.jl and "gks not in proper state" on Windows 10](https://discourse.julialang.org/t/help-with-student-issue-gr-jl-and-gks-not-in-proper-state-on-windows-10/93477)

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**Author:** [@isaacsas](https://discourse.julialang.org/u/isaacsas)\
**Replies:** 2\
**Last updated:** [January 24, 2023, 10:33pm UTC](https://discourse.julialang.org/t/help-with-student-issue-gr-jl-and-gks-not-in-proper-state-on-windows-10/93477 "2023-01-24T22:33:57Z")

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I have student getting “gks not in proper state” when trying to plot under Windows 10 using 1.9-beta-3 and a fresh Julia install with only the latest Plots.jl, IJulia, and GR explicitly added. Does anyone have suggestio…

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## [\`@inferred\` check for a small \`Union\` without being specific about the types](https://discourse.julialang.org/t/inferred-check-for-a-small-union-without-being-specific-about-the-types/93470)

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**Author:** [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Replies:** 1\
**Last updated:** [January 24, 2023, 8:55pm UTC](https://discourse.julialang.org/t/inferred-check-for-a-small-union-without-being-specific-about-the-types/93470 "2023-01-24T20:55:23Z")

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Suppose I have a function f(x) = x \> 1 ? 0 : x For this, I obtain julia\> @code\_warntype f(0.2) MethodInstance for f(::Float64) from f(x) @ Main REPL\[43\]:1 Arguments #self#::Core.Const(f) x::Float64 Body::Union{F…

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## [Multi-GPU single host training example](https://discourse.julialang.org/t/multi-gpu-single-host-training-example/73689)

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**Author:** [@avilay](https://discourse.julialang.org/u/avilay)\
**Replies:** 9\
**Last updated:** [January 24, 2023, 8:53pm UTC](https://discourse.julialang.org/t/multi-gpu-single-host-training-example/73689 "2023-01-24T20:53:38Z")

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Hello - I am completely new to Julia and just started playing around with it in the last couple of days over my winter break. Its a great language :slight\_smile: Thank you for building/maintaining it! Can somebody point…

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## [Makie - how to set only lower or upper axis limit?](https://discourse.julialang.org/t/makie-how-to-set-only-lower-or-upper-axis-limit/58320)

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**Author:** [@Kolaru](https://discourse.julialang.org/u/Kolaru)\
**Replies:** 4\
**Last updated:** [January 24, 2023, 6:54pm UTC](https://discourse.julialang.org/t/makie-how-to-set-only-lower-or-upper-axis-limit/58320 "2023-01-24T18:54:41Z")

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When plotting Makie automatically set axis limits. I would like to keep the automatically generated upper limit while setting the lower one to zero. How could I do that? At first I wanted to get the current limits and r…

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## [Using \`load()\` from MLJ inside a package](https://discourse.julialang.org/t/using-load-from-mlj-inside-a-package/93413)

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**Author:** [@v-i-s-h](https://discourse.julialang.org/u/v-i-s-h)\
**Replies:** 4\
**Last updated:** [January 24, 2023, 6:24pm UTC](https://discourse.julialang.org/t/using-load-from-mlj-inside-a-package/93413 "2023-01-24T18:24:32Z")

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Hi, I am trying to develop a package which will train multiple models according to the given input data and return the performance metrics (inspired from lazypredict · PyPI). I am using MLJ underneath to train multiple …

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## [Conda install matplotlib](https://discourse.julialang.org/t/conda-install-matplotlib/93476)

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**Author:** [@Kunz-David](https://discourse.julialang.org/u/Kunz-David)\
**Replies:** 0\
**Last updated:** [January 24, 2023, 6:06pm UTC](https://discourse.julialang.org/t/conda-install-matplotlib/93476 "2023-01-24T18:06:58Z")

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Hi all, I am installing an old project of mine which I had in julia. And I’m installing some packages and can’t install PyPlot. There seems to be a Conda error, which I can’t get rid of. My python ENV is here: ENV\[…

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## [StatsModels.jl: upcoming breaking changes to captured functions calls](https://discourse.julialang.org/t/statsmodels-jl-upcoming-breaking-changes-to-captured-functions-calls/93475)

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**Author:** [@dave.f.kleinschmidt](https://discourse.julialang.org/u/dave.f.kleinschmidt)\
**Replies:** 0\
**Last updated:** [January 24, 2023, 5:32pm UTC](https://discourse.julialang.org/t/statsmodels-jl-upcoming-breaking-changes-to-captured-functions-calls/93475 "2023-01-24T17:32:25Z")

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We recently merged a long-standing PR #183 (which some of you may remember from a juliacon talk in 2020 :scream: ) which is a fairly deep re-thinking of how we handle captured function calls, like the log in @formula(lo…

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## [How do I drop only rows that are fully filled with missing values?](https://discourse.julialang.org/t/how-do-i-drop-only-rows-that-are-fully-filled-with-missing-values/93471)

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**Author:** [@lazarusA](https://discourse.julialang.org/u/lazarusA)\
**Replies:** 3\
**Last updated:** [January 24, 2023, 4:56pm UTC](https://discourse.julialang.org/t/how-do-i-drop-only-rows-that-are-fully-filled-with-missing-values/93471 "2023-01-24T16:56:42Z")

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How do I drop only rows that are fully filled with missing values? df = DataFrame(a = \[missing,2,3,missing\], b = \[missing,5, 9, missing\], c=\[missing, 2,3,4\]) just remove row 1. I want to keep the other ones, even if t…

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## [How to save an array to disk in compressed form?](https://discourse.julialang.org/t/how-to-save-an-array-to-disk-in-compressed-form/40325)

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**Author:** [@andrey2185](https://discourse.julialang.org/u/andrey2185)\
**Replies:** 9\
**Last updated:** [January 24, 2023, 2:32pm UTC](https://discourse.julialang.org/t/how-to-save-an-array-to-disk-in-compressed-form/40325 "2023-01-24T14:32:14Z")

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Hello, how to save an array to disk in compressed form?

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## [Generation of multivariate polynomial basis with given degree](https://discourse.julialang.org/t/generation-of-multivariate-polynomial-basis-with-given-degree/60757)

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**Author:** [@iHany](https://discourse.julialang.org/u/iHany)\
**Replies:** 4\
**Last updated:** [January 24, 2023, 2:22pm UTC](https://discourse.julialang.org/t/generation-of-multivariate-polynomial-basis-with-given-degree/60757 "2023-01-24T14:22:07Z")

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Hi, I would like to make a multivariate polynomial with given degree. For example, the bivariate polynomial basis of a vector x = \[x1, y2\] with degree of 2 would be x -\> \[1, x1, x1^2, x2, x2^2, x1\*x2\]. It seems that …

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## [How do I select a line by clicking in Makie?](https://discourse.julialang.org/t/how-do-i-select-a-line-by-clicking-in-makie/93410)

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**Author:** [@vladdez](https://discourse.julialang.org/u/vladdez)\
**Replies:** 4\
**Last updated:** [January 24, 2023, 1:48pm UTC](https://discourse.julialang.org/t/how-do-i-select-a-line-by-clicking-in-makie/93410 "2023-01-24T13:48:29Z")

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I want to be able to select a line on the plot by clicking on it. Ideally, when I click on any line, the number of that line will appear on the screen. I wrote my code based on the tutorial, but there is no example with …

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## [Unclear number of States in simple example](https://discourse.julialang.org/t/unclear-number-of-states-in-simple-example/93446)

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**Author:** [@johhell](https://discourse.julialang.org/u/johhell)\
**Replies:** 6\
**Last updated:** [January 24, 2023, 1:01pm UTC](https://discourse.julialang.org/t/unclear-number-of-states-in-simple-example/93446 "2023-01-24T13:01:12Z")

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I tested a simple component-based electrical example with a resistor, capacitor and an inductor. An additional resistor is connected in parallel with the inductor. using ModelingToolkit using LinearAlgebra @variables t…

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## [PackageCompiler libs and Python: Passing numpy arrays (or structs)](https://discourse.julialang.org/t/packagecompiler-libs-and-python-passing-numpy-arrays-or-structs/93406)

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**Author:** [@wave\_and\_matter](https://discourse.julialang.org/u/wave_and_matter)\
**Replies:** 7\
**Last updated:** [January 24, 2023, 12:36pm UTC](https://discourse.julialang.org/t/packagecompiler-libs-and-python-passing-numpy-arrays-or-structs/93406 "2023-01-24T12:36:05Z")

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I have succesfully tried out the PackageCompiler library + Python Ctypes example from Sadly the example is extremely simple and does not show how to pass parameters, especially arrays from python. I would be thankful …

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## [Getting different result from serial and multithreaded code in Julia](https://discourse.julialang.org/t/getting-different-result-from-serial-and-multithreaded-code-in-julia/93257)

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**Author:** [@Sudipta\_Chakraborty](https://discourse.julialang.org/u/Sudipta_Chakraborty)\
**Replies:** 30\
**Last updated:** [January 24, 2023, 12:33pm UTC](https://discourse.julialang.org/t/getting-different-result-from-serial-and-multithreaded-code-in-julia/93257 "2023-01-24T12:33:59Z")

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For the following code when I am starting with export JULIA\_NUM\_THREADS=1, which is basically equivalent to a serial code it gives me a different output for matrix final\_result in comparison to when I am doing export JUL…

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## [A package for sentry.io integration - looking for testers](https://discourse.julialang.org/t/a-package-for-sentry-io-integration-looking-for-testers/64961)

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**Author:** [@pengwyn](https://discourse.julialang.org/u/pengwyn)\
**Replies:** 8\
**Last updated:** [January 24, 2023, 10:41am UTC](https://discourse.julialang.org/t/a-package-for-sentry-io-integration-looking-for-testers/64961 "2023-01-24T10:41:05Z")

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A little while ago I wrote a package SentryIntegration.jl to interface with Sentry (https://sentry.io) and I wanted to let people know of it in case it helps others and to get some feedback. A quick description on Sentr…

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## [How to produce a waterfall plot in Julia?](https://discourse.julialang.org/t/how-to-produce-a-waterfall-plot-in-julia/93441)

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**Author:** [@fusion809](https://discourse.julialang.org/u/fusion809)\
**Replies:** 6\
**Last updated:** [January 24, 2023, 12:22pm UTC](https://discourse.julialang.org/t/how-to-produce-a-waterfall-plot-in-julia/93441 "2023-01-24T12:22:28Z")

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I want to produce a waterfall plot, sort of like this: in Julia. The above plot was created in MATLAB with the command: waterfall(xi, tdata, abs(u1data')) where xi and tdata was 1d arrays and u1data is a 2d array c…

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## [What about an \`undefs\` function in \`Base\`?](https://discourse.julialang.org/t/what-about-an-undefs-function-in-base/92690)

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**Author:** [@alex-s-gardner](https://discourse.julialang.org/u/alex-s-gardner)\
**Replies:** 64\
**Last updated:** [January 24, 2023, 10:58am UTC](https://discourse.julialang.org/t/what-about-an-undefs-function-in-base/92690 "2023-01-24T10:58:38Z")

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It would be nice to have an undefs function that operates the same way as zeros and ones. The syntax for initializing an array of zeros or ones is more concise than initializing an array of undefs but is not as efficient…

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