# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1575

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

**Page:** 1576

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## [Flux Pendulum DDPG example fails on GPU](https://discourse.julialang.org/t/flux-pendulum-ddpg-example-fails-on-gpu/49975)

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**Author:** [@lilanger](https://discourse.julialang.org/u/lilanger)\
**Replies:** 2\
**Last updated:** [November 12, 2020, 9:52am UTC](https://discourse.julialang.org/t/flux-pendulum-ddpg-example-fails-on-gpu/49975 "2020-11-12T09:52:55Z")

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I am pretty new to Flux and try to get the Pendulum environment (using a slightly modified Reinforce.jl environment: Pendulum update) running with DDPG with newer package versions (based on Flux model-zoo). It seems to …

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## [Code runs fine on Juno and Intellij-Idea but crashes on VSCode. ArgumentError: Package OffsetArrays does not have Adapt in its dependencies](https://discourse.julialang.org/t/code-runs-fine-on-juno-and-intellij-idea-but-crashes-on-vscode-argumenterror-package-offsetarrays-does-not-have-adapt-in-its-dependencies/50015)

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**Author:** [@acycliq](https://discourse.julialang.org/u/acycliq)\
**Replies:** 2\
**Last updated:** [November 12, 2020, 9:23am UTC](https://discourse.julialang.org/t/code-runs-fine-on-juno-and-intellij-idea-but-crashes-on-vscode-argumenterror-package-offsetarrays-does-not-have-adapt-in-its-dependencies/50015 "2020-11-12T09:23:26Z")

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I am trying to use some code from a GitHub repo. I have cloned it and the code has a. jl file that defines a module and I think (but not 100% sure) that I am successfully loading the module from my local directory The c…

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## [Reuse results from @example blocks](https://discourse.julialang.org/t/reuse-results-from-example-blocks/49908)

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**Author:** [@tomhaber](https://discourse.julialang.org/u/tomhaber)\
**Replies:** 2\
**Last updated:** [November 12, 2020, 9:22am UTC](https://discourse.julialang.org/t/reuse-results-from-example-blocks/49908 "2020-11-12T09:22:47Z")

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I’m writing some documentation using Documenter.jl and would like to create a sort of follow along guide (like a jupyter notebook). Currently, I’m using @example blocks for showing the code and the results of that compu…

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## [Gradients of a simple function using ForwardDiff yields errorenous results? - Or am I doing something wrong?](https://discourse.julialang.org/t/gradients-of-a-simple-function-using-forwarddiff-yields-errorenous-results-or-am-i-doing-something-wrong/50035)

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**Author:** [@vettert](https://discourse.julialang.org/u/vettert)\
**Replies:** 2\
**Last updated:** [November 12, 2020, 9:21am UTC](https://discourse.julialang.org/t/gradients-of-a-simple-function-using-forwarddiff-yields-errorenous-results-or-am-i-doing-something-wrong/50035 "2020-11-12T09:21:07Z")

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I would like to calculate the gradient of a simple function using FowardDiff.gradient, but I have been encountering problems, where I have gotten different answers from code that should seemingly be doing the same thing. …

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## [REPL text colors for white background console](https://discourse.julialang.org/t/repl-text-colors-for-white-background-console/49999)

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**Author:** [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Replies:** 3\
**Last updated:** [November 12, 2020, 8:02am UTC](https://discourse.julialang.org/t/repl-text-colors-for-white-background-console/49999 "2020-11-12T08:02:09Z")

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My Win10 Julia 1.5.2 REPL has white background and the default light yellow text (ex: ?help, matching parentheses highlighted, etc.) cannot be read. Is there a way to change this color (ex: to cyan)? I am using a Git ba…

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## [Help with deprecation warnings in tests](https://discourse.julialang.org/t/help-with-deprecation-warnings-in-tests/50011)

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**Author:** [@pdeffebach](https://discourse.julialang.org/u/pdeffebach)\
**Replies:** 1\
**Last updated:** [November 12, 2020, 7:49am UTC](https://discourse.julialang.org/t/help-with-deprecation-warnings-in-tests/50011 "2020-11-12T07:49:51Z")

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I would like to test that a function emits a deprecation warning, but I keep getting errors. Can someone please help me get the right syntax? Here is an MWE julia\> function foo() Base.depwarn("use an argument", :…

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## [GLMakie.jl crashed when building the scene](https://discourse.julialang.org/t/glmakie-jl-crashed-when-building-the-scene/50025)

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**Author:** [@AquaIndigo](https://discourse.julialang.org/u/AquaIndigo)\
**Replies:** 1\
**Last updated:** [November 12, 2020, 7:18am UTC](https://discourse.julialang.org/t/glmakie-jl-crashed-when-building-the-scene/50025 "2020-11-12T07:18:13Z")

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When I just imported the package and built a scene on my manjaro machine, crash occured(segfault): julia\> using Makie julia\> scene = Scene() signal (11): 段错误 in expression starting at none:0 \_ZN4llvm16TargetPassConfig…

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## [Writing Parquet files](https://discourse.julialang.org/t/writing-parquet-files/11221)

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**Author:** [@tk3369](https://discourse.julialang.org/u/tk3369)\
**Replies:** 28\
**Last updated:** [November 12, 2020, 6:59am UTC](https://discourse.julialang.org/t/writing-parquet-files/11221 "2020-11-12T06:59:02Z")

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Is it possible to write Parquet files from Julia? I found Parquet.jl but looks like it can read but not write…

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## [DataFrame and Missings.replace()](https://discourse.julialang.org/t/dataframe-and-missings-replace/9834)

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**Author:** [@johann.spies](https://discourse.julialang.org/u/johann.spies)\
**Replies:** 10\
**Last updated:** [November 12, 2020, 5:28am UTC](https://discourse.julialang.org/t/dataframe-and-missings-replace/9834 "2020-11-12T05:28:57Z")

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Why does this example (adapted from the DataFrames documentation) work: julia\> x = \[1, 2, missing\] 3-element Array{Union{Int64, Missings.Missing},1}: 1 2 missing julia\> df = collect(Missings.replace(x…

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## [\[Help\] Plot/export of solutions from PDE](https://discourse.julialang.org/t/help-plot-export-of-solutions-from-pde/50020)

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**Author:** [@jinkel7](https://discourse.julialang.org/u/jinkel7)\
**Replies:** 0\
**Last updated:** [November 12, 2020, 3:06am UTC](https://discourse.julialang.org/t/help-plot-export-of-solutions-from-pde/50020 "2020-11-12T03:06:30Z")

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Hello, I’m quite new to Julia. I’m having a problem with “plot” and “exporting”. Can anyone give help for a newbie? Using VoronoiFVM for one-dimensional PDE, the solution is expressed as Array{Float64,1}. I want to e…

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## [Searchsorted with by and lookup](https://discourse.julialang.org/t/searchsorted-with-by-and-lookup/49952)

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**Author:** [@endremborza](https://discourse.julialang.org/u/endremborza)\
**Replies:** 4\
**Last updated:** [November 12, 2020, 2:38am UTC](https://discourse.julialang.org/t/searchsorted-with-by-and-lookup/49952 "2020-11-12T02:38:43Z")

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a = \[1,3,2,4,1,2,1\]; is = sortperm(a); after this, I’d assume is\[searchsorted(is, q, by=x -\> a\[x\])\] should work to find indices in a that contain q, however: a\[is\[searchsorted(is, 3, by=x -\> a\[x\])\]\] 2-element Array{Int…

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## [Is there a way to make a submodule "open"](https://discourse.julialang.org/t/is-there-a-way-to-make-a-submodule-open/49641)

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**Author:** [@mhinsch](https://discourse.julialang.org/u/mhinsch)\
**Replies:** 21\
**Last updated:** [November 12, 2020, 12:33am UTC](https://discourse.julialang.org/t/is-there-a-way-to-make-a-submodule-open/49641 "2020-11-12T00:33:59Z")

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The scenario: I am writing a DSLish set of macros that create a few functions that again call code the user has provided verbatim (in the macro call), so something like this: @mymacro Bla myfun1() myfun2() end …

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## [Plots (pgfplotsx) change label from Column -\> Line](https://discourse.julialang.org/t/plots-pgfplotsx-change-label-from-column-line/50009)

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**Author:** [@JosephPollacco](https://discourse.julialang.org/u/JosephPollacco)\
**Replies:** 2\
**Last updated:** [November 11, 2020, 11:32pm UTC](https://discourse.julialang.org/t/plots-pgfplotsx-change-label-from-column-line/50009 "2020-11-11T23:32:05Z")

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A great thanks for the introduction of PgfPlotsX into Plots making the plotting accessible to everybody. I would need to transform the Label from 1 column to multiple column. This feature is particularly useful when usi…

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## [Workaround for BSON "Inexact: trunc" error for saving very large files?](https://discourse.julialang.org/t/workaround-for-bson-inexact-trunc-error-for-saving-very-large-files/49767)

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**Author:** [@CosmoProf](https://discourse.julialang.org/u/CosmoProf)\
**Replies:** 5\
**Last updated:** [November 11, 2020, 11:10pm UTC](https://discourse.julialang.org/t/workaround-for-bson-inexact-trunc-error-for-saving-very-large-files/49767 "2020-11-11T23:10:19Z")

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Hi, I’m experiencing an (apparently known) error using BSON to try to save very large files, where it throws an error: InexactError: trunc(Int32, 2299858984), when the file to be saved is too large. This has been discuss…

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## [\[ANN\] YAActL 0.2, Yet Another Actor Library (built in Julia)](https://discourse.julialang.org/t/ann-yaactl-0-2-yet-another-actor-library-built-in-julia/48637)

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**Author:** [@pbayer](https://discourse.julialang.org/u/pbayer)\
**Replies:** 43\
**Last updated:** [November 11, 2020, 10:43pm UTC](https://discourse.julialang.org/t/ann-yaactl-0-2-yet-another-actor-library-built-in-julia/48637 "2020-11-11T22:43:35Z")

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I am happy to announce YAActL, a new actor library for concurrent programming in Julia. An Actor is a computational entity that, in response to a message it receives, can concurrently: send a finite number of message…

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## [DifferentialEquations and derivatives of solutions?](https://discourse.julialang.org/t/differentialequations-and-derivatives-of-solutions/49995)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 2\
**Last updated:** [November 11, 2020, 10:23pm UTC](https://discourse.julialang.org/t/differentialequations-and-derivatives-of-solutions/49995 "2020-11-11T22:23:44Z")

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Suppose I use the DifferentialEquations.jl package and find a solution structure sol. Is there a simple way to find the derivative of the various variables in sol? In other words: suppose I have 6 states in an ODE model…

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## [Printing Jump NLexpression during solution](https://discourse.julialang.org/t/printing-jump-nlexpression-during-solution/49928)

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**Author:** [@floswald](https://discourse.julialang.org/u/floswald)\
**Replies:** 1\
**Last updated:** [November 11, 2020, 9:59pm UTC](https://discourse.julialang.org/t/printing-jump-nlexpression-during-solution/49928 "2020-11-11T21:59:38Z")

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i’m having trouble debugging my NL model in Jump. Here is a MWE: using JuMP, Ipopt function j\_test(a) m = Model(Ipopt.Optimizer) @variable(m,x \>= 1.0) @variable(m,y) @NLexpression(m, q, x^a + log(x + a) ) …

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## [Increment elements of array by index](https://discourse.julialang.org/t/increment-elements-of-array-by-index/49694)

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**Author:** [@dfdx](https://discourse.julialang.org/u/dfdx)\
**Replies:** 10\
**Last updated:** [November 11, 2020, 9:51pm UTC](https://discourse.julialang.org/t/increment-elements-of-array-by-index/49694 "2020-11-11T21:51:52Z")

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Given an array A, indices I and values v, I want to add elements of v to A at I. Something like this: A = zeros(4) I = \[1, 3\] v = \[1, 1\] # partial solution A\[I\] .+= v Now the hard part: Indices may repeat, e.g. I = …

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## [Problems using JuliaMono in VsCode](https://discourse.julialang.org/t/problems-using-juliamono-in-vscode/49936)

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**Author:** [@Carsten](https://discourse.julialang.org/u/Carsten)\
**Replies:** 12\
**Last updated:** [November 11, 2020, 9:50pm UTC](https://discourse.julialang.org/t/problems-using-juliamono-in-vscode/49936 "2020-11-11T21:50:54Z")

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I’ve got in trouble after adding the JuliaMono fonts along the description given in https://cormullion.github.io/pages/2020-07-26-JuliaMono/#windows The result within the terminal window looks like (all text are in mon…

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## [Advice for improving Monte-Carlo code](https://discourse.julialang.org/t/advice-for-improving-monte-carlo-code/49782)

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**Author:** [@s0916314](https://discourse.julialang.org/u/s0916314)\
**Replies:** 23\
**Last updated:** [November 11, 2020, 9:17pm UTC](https://discourse.julialang.org/t/advice-for-improving-monte-carlo-code/49782 "2020-11-11T21:17:43Z")

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I’m a relative beginner with Julia and was hoping someone may be able to give me some constructive feedback on a small script I’ve written. I’m mainly looking for performance tips and ways to make my code clearer or less…

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## [How do you debug in Intellj?](https://discourse.julialang.org/t/how-do-you-debug-in-intellj/49998)

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**Author:** [@acycliq](https://discourse.julialang.org/u/acycliq)\
**Replies:** 3\
**Last updated:** [November 11, 2020, 8:58pm UTC](https://discourse.julialang.org/t/how-do-you-debug-in-intellj/49998 "2020-11-11T20:58:37Z")

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I am using the Intellij Idea IDE with the Julia plugin. I am putting a breakpoint but it is getting ignored. I am pressing the bug-like icon, but flow does not stop at the breakpoint. What am I missing please? Is it r…

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## [How do I use eigen! with my input matrix?](https://discourse.julialang.org/t/how-do-i-use-eigen-with-my-input-matrix/49997)

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**Author:** [@Noel\_Araujo](https://discourse.julialang.org/u/Noel_Araujo)\
**Replies:** 4\
**Last updated:** [November 11, 2020, 7:42pm UTC](https://discourse.julialang.org/t/how-do-i-use-eigen-with-my-input-matrix/49997 "2020-11-11T19:42:35Z")

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Hello I have an idea, but i don’t know how to implemented it. I would like to pass a temporary variables to store the eigenvectors of eigen! - by default eigen! uses the original matrix. I am confident that this is pos…

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## [Postdoc position in numerical linear algebra (Uruguay-Germany)](https://discourse.julialang.org/t/postdoc-position-in-numerical-linear-algebra-uruguay-germany/49996)

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**Author:** [@mforets](https://discourse.julialang.org/u/mforets)\
**Replies:** 0\
**Last updated:** [November 11, 2020, 5:50pm UTC](https://discourse.julialang.org/t/postdoc-position-in-numerical-linear-algebra-uruguay-germany/49996 "2020-11-11T17:50:07Z")

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Hi all, There is an open postdoc position at my university (Universidad de la República, Uruguay), joint with the Max Planck Institute for Dynamics of Complex Technical Systems (Germany), see description below. While it…

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## [IJulia error syntax: undefined reference in AST](https://discourse.julialang.org/t/ijulia-error-syntax-undefined-reference-in-ast/49958)

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**Author:** [@Mason](https://discourse.julialang.org/u/Mason)\
**Replies:** 6\
**Last updated:** [November 11, 2020, 4:53pm UTC](https://discourse.julialang.org/t/ijulia-error-syntax-undefined-reference-in-ast/49958 "2020-11-11T16:53:23Z")

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Suddenly when I try to start up IJulia and run any code in a Jupyter notebook or jupyter lab (e.g. just return the number 1), I get an error: syntax: undefined reference in AST Stacktrace: \[1\] top-level scope at In\[1\]…

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## [\_generate\_2d\_nodes! in JuAFEM](https://discourse.julialang.org/t/generate-2d-nodes-in-juafem/49990)

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**Author:** [@Hrishikesh\_Das](https://discourse.julialang.org/u/Hrishikesh_Das)\
**Replies:** 0\
**Last updated:** [November 11, 2020, 4:05pm UTC](https://discourse.julialang.org/t/generate-2d-nodes-in-juafem/49990 "2020-11-11T16:05:49Z")

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I am trying to use the function \_generate\_2d\_nodes! which is available in JuAFEM. But it shows an error. Below is my code using Tensors, JuAFEM M =\_generate\_2d\_nodes!(44, 21, 21, Vec{2}((0.0,4.5)), Vec{2}((0.5,4.5)), …

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## [Sparse Gradient using Zygote & Optim](https://discourse.julialang.org/t/sparse-gradient-using-zygote-optim/49087)

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**Author:** [@sobhan](https://discourse.julialang.org/u/sobhan)\
**Replies:** 2\
**Last updated:** [November 11, 2020, 3:59pm UTC](https://discourse.julialang.org/t/sparse-gradient-using-zygote-optim/49087 "2020-11-11T15:59:31Z")

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I’m trying to minimize a function and i use Zygote to calculate the derivatives to minimize it with BFGS(from Optim), Can i get sparse gradient/hessiens and use them with optim. I really need to switch to sparse since on…

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## [Redefining modules in VS Code](https://discourse.julialang.org/t/redefining-modules-in-vs-code/49978)

<div class="topic-metadata">

**Author:** [@evanfields](https://discourse.julialang.org/u/evanfields)\
**Replies:** 1\
**Last updated:** [November 11, 2020, 3:08pm UTC](https://discourse.julialang.org/t/redefining-modules-in-vs-code/49978 "2020-11-11T15:08:25Z")

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I have a tiny file defining a module: module A using Dates: now println("Module $(@\_\_MODULE\_\_) defined at $(now())") end If I do Julia: Execute File three times, the REPL output is like so: Module Main.A defined at 20…

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## [Plotlyjs or gr](https://discourse.julialang.org/t/plotlyjs-or-gr/49984)

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**Author:** [@Debraj\_Bhal](https://discourse.julialang.org/u/Debraj_Bhal)\
**Replies:** 5\
**Last updated:** [November 11, 2020, 2:42pm UTC](https://discourse.julialang.org/t/plotlyjs-or-gr/49984 "2020-11-11T14:42:20Z")

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Is plotlyjs a separate pkg or it is a backend in plots as gr?

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## [Bug in Julia's ode solver : UndefVarError: hasproperty not defined](https://discourse.julialang.org/t/bug-in-julias-ode-solver-undefvarerror-hasproperty-not-defined/49949)

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**Author:** [@iamsuddhasattwa](https://discourse.julialang.org/u/iamsuddhasattwa)\
**Replies:** 6\
**Last updated:** [November 11, 2020, 2:28pm UTC](https://discourse.julialang.org/t/bug-in-julias-ode-solver-undefvarerror-hasproperty-not-defined/49949 "2020-11-11T14:28:41Z")

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I am having the following inexplicable error when I try to solve an ode. Can you help me interpret the error message. julia\> include("t.jl"); ERROR: LoadError: UndefVarError: hasproperty not defined Stacktrace: \[1\] che…

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## [What's the fastest CPU execution model?](https://discourse.julialang.org/t/whats-the-fastest-cpu-execution-model/49682)

<div class="topic-metadata">

**Author:** [@teriiju](https://discourse.julialang.org/u/teriiju)\
**Replies:** 6\
**Last updated:** [November 11, 2020, 1:50pm UTC](https://discourse.julialang.org/t/whats-the-fastest-cpu-execution-model/49682 "2020-11-11T13:50:13Z")

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Hi, naive question from a newbie, is a binary program execution the fastest way to execute a small program today - or - are there some CPUS models nowadays in which one could configure a set of instruction to run an equ…

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