# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1307

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

**Page:** 1308

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## [Pkg missing?](https://discourse.julialang.org/t/pkg-missing/65971)

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**Author:** [@dgpdx](https://discourse.julialang.org/u/dgpdx)\
**Replies:** 4\
**Last updated:** [August 7, 2021, 2:48am UTC](https://discourse.julialang.org/t/pkg-missing/65971 "2021-08-07T02:48:38Z")

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I’m using julia on an m1 MacBookPro. When I try to install a package using Pkg.add(PackageName) I get “Pkg not defined” What is going on here? can anyone point me in the right direction? Don Groves

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## [Choosing between Shell, Emacs, and VSCode](https://discourse.julialang.org/t/choosing-between-shell-emacs-and-vscode/65968)

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**Author:** [@greatpet](https://discourse.julialang.org/u/greatpet)\
**Replies:** 3\
**Last updated:** [August 7, 2021, 1:55am UTC](https://discourse.julialang.org/t/choosing-between-shell-emacs-and-vscode/65968 "2021-08-07T01:55:30Z")

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What are the relative strengths and weaknesses of the following three environments? 1. REPL in terminal. 2. Emacs + julia-mode + julia-repl-mode. 3. VSCode with Julia extension. Specifically, between the Julia plugins f…

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## [PlotlyJS: how to introduce shapes into time series?](https://discourse.julialang.org/t/plotlyjs-how-to-introduce-shapes-into-time-series/65955)

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**Author:** [@VivMendes](https://discourse.julialang.org/u/VivMendes)\
**Replies:** 5\
**Last updated:** [August 7, 2021, 12:25am UTC](https://discourse.julialang.org/t/plotlyjs-how-to-introduce-shapes-into-time-series/65955 "2021-08-07T00:25:27Z")

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Hi, I need to insert shapes into a time series using PlotlyJS, and name them. I know how to do it using Plots or PGFPlotsX. For example, what I want is something similar to the following plot, produced with PGFPlotsX aft…

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## [How to properly create, activate, and resume, an environment in VSCode](https://discourse.julialang.org/t/how-to-properly-create-activate-and-resume-an-environment-in-vscode/48289)

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**Author:** [@Torkel](https://discourse.julialang.org/u/Torkel)\
**Replies:** 8\
**Last updated:** [August 7, 2021, 12:21am UTC](https://discourse.julialang.org/t/how-to-properly-create-activate-and-resume-an-environment-in-vscode/48289 "2021-08-07T00:21:15Z")

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I am trying to create a new Julia environment in VSCode, and run some stuff from it. However, I have a feeling that I might not have really grasped how to do this properly. It would be good if someone could have a look a…

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## [Using variable names to parse DataFrame](https://discourse.julialang.org/t/using-variable-names-to-parse-dataframe/65969)

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**Author:** [@cwallj](https://discourse.julialang.org/u/cwallj)\
**Replies:** 6\
**Last updated:** [August 7, 2021, 12:00am UTC](https://discourse.julialang.org/t/using-variable-names-to-parse-dataframe/65969 "2021-08-07T00:00:02Z")

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Hi everyone! I’m brand new to Julia (and fairly new to coding in general). I’m currently trying to write a function that will edit an object of type DataFrame to make it workable for the Ripserer package. The function wo…

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## [Emacs + lsp mode](https://discourse.julialang.org/t/emacs-lsp-mode/53427)

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**Author:** [@dean](https://discourse.julialang.org/u/dean)\
**Replies:** 7\
**Last updated:** [August 6, 2021, 11:11pm UTC](https://discourse.julialang.org/t/emacs-lsp-mode/53427 "2021-08-06T23:11:27Z")

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Hello guys! Been following this discourse for the last two weeks and got a lot of nice tips ! :slight\_smile: So Juno is great, as well as VS code, but I am into Emacs and I would really like to make it work. I am havi…

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## [Type inference with a tuple slice](https://discourse.julialang.org/t/type-inference-with-a-tuple-slice/33650)

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**Author:** [@tomohiro\_soejima](https://discourse.julialang.org/u/tomohiro_soejima)\
**Replies:** 13\
**Last updated:** [August 6, 2021, 10:20pm UTC](https://discourse.julialang.org/t/type-inference-with-a-tuple-slice/33650 "2021-08-06T22:20:07Z")

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Hi, I’m playing around with NTuple to better familiarize myself with variable length function argument etc. In the process, I encountered an example where type inference failed. Here is a minimal example. function test…

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## [Why won't Symbolics.jl simplify \`sqrt(1)\` to \`1\`?](https://discourse.julialang.org/t/why-wont-symbolics-jl-simplify-sqrt-1-to-1/65921)

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**Author:** [@Samuel\_Ainsworth](https://discourse.julialang.org/u/Samuel_Ainsworth)\
**Replies:** 5\
**Last updated:** [August 6, 2021, 8:42pm UTC](https://discourse.julialang.org/t/why-wont-symbolics-jl-simplify-sqrt-1-to-1/65921 "2021-08-06T20:42:09Z")

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@variables x sqrt(cos(x)^2 + sin(x)^2) |\> simplify gives me sqrt(1). Why isn’t this reduced to simply 1? OTOH sqrt(0\*x+1) |\> simplify reduces to 1, no problem.

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## [DataFrames: ByRow fails in transform with PooledArrays after CSV.read](https://discourse.julialang.org/t/dataframes-byrow-fails-in-transform-with-pooledarrays-after-csv-read/65957)

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**Author:** [@hdavid16](https://discourse.julialang.org/u/hdavid16)\
**Replies:** 6\
**Last updated:** [August 6, 2021, 7:57pm UTC](https://discourse.julialang.org/t/dataframes-byrow-fails-in-transform-with-pooledarrays-after-csv-read/65957 "2021-08-06T19:57:54Z")

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I am having an issue with a transform operation on a DataFrame that is read from a .csv using CSV. I don’t have the following issue when my dataframe has few rows because the importing from the .csv file uses SentinelArr…

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## [How to include a module from a specific path directory in REPL of VS Code?](https://discourse.julialang.org/t/how-to-include-a-module-from-a-specific-path-directory-in-repl-of-vs-code/65914)

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**Author:** [@Amro](https://discourse.julialang.org/u/Amro)\
**Replies:** 5\
**Last updated:** [August 6, 2021, 7:30pm UTC](https://discourse.julialang.org/t/how-to-include-a-module-from-a-specific-path-directory-in-repl-of-vs-code/65914 "2021-08-06T19:30:32Z")

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I have a module called (SynchronousMachines) in this path directory (C:\\Work\\Julia\\Simulation\\SynchronousMachine), as seen below: I need to include this module from the RELP (not main code) in VS code. For this I am …

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## [\[ANN\] VS Code extension 1.3 released](https://discourse.julialang.org/t/ann-vs-code-extension-1-3-released/65453)

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**Author:** [@davidanthoff](https://discourse.julialang.org/u/davidanthoff)\
**Replies:** 38\
**Last updated:** [August 6, 2021, 6:49pm UTC](https://discourse.julialang.org/t/ann-vs-code-extension-1-3-released/65453 "2021-08-06T18:49:55Z")

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Hey everyone, we just released version 1.3 of the Julia extension for VS Code, which brings a bunch of new features: Experimental native Jupyter notebook support. With this feature you can work with Jupyter Notebooks …

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## [Compiler work priorities](https://discourse.julialang.org/t/compiler-work-priorities/17623)

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**Author:** [@StefanKarpinski](https://discourse.julialang.org/u/StefanKarpinski)\
**Replies:** 122\
**Last updated:** [August 6, 2021, 6:01pm UTC](https://discourse.julialang.org/t/compiler-work-priorities/17623 "2021-08-06T18:01:07Z")

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In response to I thought I might write a little post about the rough priorities of the compiler team: Correctness finding and fixing compiler and inference bugs Multithreading non-copying task stack switching (d…

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## [How to convert multi-dimensional indices into one-dimensional indices](https://discourse.julialang.org/t/how-to-convert-multi-dimensional-indices-into-one-dimensional-indices/65950)

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**Author:** [@Valery](https://discourse.julialang.org/u/Valery)\
**Replies:** 3\
**Last updated:** [August 6, 2021, 5:05pm UTC](https://discourse.julialang.org/t/how-to-convert-multi-dimensional-indices-into-one-dimensional-indices/65950 "2021-08-06T17:05:41Z")

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A = rand(3,3) b = findall(A .\> .5) For instance: 3-element Vector{CartesianIndex{2}}: CartesianIndex(1,1) CartesianIndex(3,1) CartesianIndex(2,2) How to do if I want b to contain the corresponding Int to access the ar…

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## [Findall() but returning a bool array](https://discourse.julialang.org/t/findall-but-returning-a-bool-array/65934)

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**Author:** [@Valery](https://discourse.julialang.org/u/Valery)\
**Replies:** 3\
**Last updated:** [August 6, 2021, 4:27pm UTC](https://discourse.julialang.org/t/findall-but-returning-a-bool-array/65934 "2021-08-06T16:27:08Z")

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Hi all, I would have liked the findall() function to return booleans. Code example: A = \[1 2; 3 4\] B = findall(\>(2),A) C = \[0 0; 1 1\] B == C This code will obviously return false at the B==C assertion. What should I …

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## [Length(skipmissing( )) not implemented](https://discourse.julialang.org/t/length-skipmissing-not-implemented/65943)

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**Author:** [@tomtom](https://discourse.julialang.org/u/tomtom)\
**Replies:** 7\
**Last updated:** [August 6, 2021, 4:24pm UTC](https://discourse.julialang.org/t/length-skipmissing-not-implemented/65943 "2021-08-06T16:24:48Z")

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julia\> x = \[2.0, missing, 3.0\]; julia\> length(x) 3 julia\> length(skipmissing(x)) ERROR: MethodError: no method matching length(::Base.SkipMissing{Vector{Union{Missing, Float64}}}) julia\> count(a -\> true, skipmissing(x…

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## [From a Julia program, run a ffmpeg shell command on a folder of files to make a mp4 movie](https://discourse.julialang.org/t/from-a-julia-program-run-a-ffmpeg-shell-command-on-a-folder-of-files-to-make-a-mp4-movie/65910)

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**Author:** [@nelsonah](https://discourse.julialang.org/u/nelsonah)\
**Replies:** 2\
**Last updated:** [August 6, 2021, 4:10pm UTC](https://discourse.julialang.org/t/from-a-julia-program-run-a-ffmpeg-shell-command-on-a-folder-of-files-to-make-a-mp4-movie/65910 "2021-08-06T16:10:53Z")

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Presently I have a Julia script file that generates a folder of jpeg files. Then I launch Windows PowerShell in that folder and execute my ffmpeg command such as: ffmpeg -r 50 -start\_number 10001 -i i\_%5d.jpeg -c:v lib…

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## [Key BlackBoxOptim not found](https://discourse.julialang.org/t/key-blackboxoptim-not-found/65919)

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**Author:** [@mengxiaoliu](https://discourse.julialang.org/u/mengxiaoliu)\
**Replies:** 1\
**Last updated:** [August 6, 2021, 2:49pm UTC](https://discourse.julialang.org/t/key-blackboxoptim-not-found/65919 "2021-08-06T14:49:00Z")

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Hello, I am examining the parallel computing speed in BlackBoxOptim by optimizing the Rosebrock function using codes adapted from rosenbrock\_parallel.jl by @robertfeldt. The code I run is as follows: using Distributed …

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## [Type promotion not working as expected](https://discourse.julialang.org/t/type-promotion-not-working-as-expected/65944)

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**Author:** [@AronT](https://discourse.julialang.org/u/AronT)\
**Replies:** 7\
**Last updated:** [August 6, 2021, 2:22pm UTC](https://discourse.julialang.org/t/type-promotion-not-working-as-expected/65944 "2021-08-06T14:22:26Z")

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So I am learning Julia from Erik Engheim’s book “Julia for Beginners”. I am working through the code as I read the book (I put all my work in Github if anyone else is using the book and want to compare their own code) H…

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## [A .= circshift(b, shfts) and circshift!(a, b, shfts)](https://discourse.julialang.org/t/a-circshift-b-shfts-and-circshift-a-b-shfts/65887)

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**Author:** [@ihgalq](https://discourse.julialang.org/u/ihgalq)\
**Replies:** 27\
**Last updated:** [August 6, 2021, 1:31pm UTC](https://discourse.julialang.org/t/a-circshift-b-shfts-and-circshift-a-b-shfts/65887 "2021-08-06T13:31:28Z")

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Hi all, I’m learning Julia by reimplementing some of my numerical algorithms. As far as I understand from the manual and language design, the following two operations should be equivalent: a .= circshift(b, shifts) …

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## [Quality of life improvements for ModelingToolkit/DiffEq/SciML ecosystem](https://discourse.julialang.org/t/quality-of-life-improvements-for-modelingtoolkit-diffeq-sciml-ecosystem/65939)

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**Author:** [@dawbarton](https://discourse.julialang.org/u/dawbarton)\
**Replies:** 1\
**Last updated:** [August 6, 2021, 12:14pm UTC](https://discourse.julialang.org/t/quality-of-life-improvements-for-modelingtoolkit-diffeq-sciml-ecosystem/65939 "2021-08-06T12:14:40Z")

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I’m applying for funding for a research software engineer to do some quality-of-life improvements for the ModelingToolkit/DiffEq/SciML ecosystem from one of the research councils in the UK (specifically the EPSRC Softwar…

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## [Why does Base only have Merge Insertion and Quick sorting algorithms?](https://discourse.julialang.org/t/why-does-base-only-have-merge-insertion-and-quick-sorting-algorithms/65210)

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**Author:** [@Lilith](https://discourse.julialang.org/u/Lilith)\
**Replies:** 16\
**Last updated:** [August 6, 2021, 12:07pm UTC](https://discourse.julialang.org/t/why-does-base-only-have-merge-insertion-and-quick-sorting-algorithms/65210 "2021-08-06T12:07:40Z")

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base/sort.jl has the algorithms InsertionSort, MergeSort, and QuickSort, yet I hear folks talk about counting, radix, and TimSort builtin to julia (e.g. https://julia-ylwu.readthedocs.io/en/latest/stdlib/sort.html for Ti…

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## [Savefig() in Plots.jl is slow when I scatter 13056 points](https://discourse.julialang.org/t/savefig-in-plots-jl-is-slow-when-i-scatter-13056-points/54443)

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**Author:** [@Lian\_Yunlong](https://discourse.julialang.org/u/Lian_Yunlong)\
**Replies:** 22\
**Last updated:** [August 6, 2021, 11:02am UTC](https://discourse.julialang.org/t/savefig-in-plots-jl-is-slow-when-i-scatter-13056-points/54443 "2021-08-06T11:02:38Z")

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Hi everyone, I am using Plots with pyplot() backend. I have a set of ~200 points to scatter, each of them has a unique marker size and color. I also need to plot several lines. After all steps with plot!() and scatter!(…

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## [\[ANN\] EasyML.jl v0.2.0 - a foolproof way of doing ML with GUI elements](https://discourse.julialang.org/t/ann-easyml-jl-v0-2-0-a-foolproof-way-of-doing-ml-with-gui-elements/65936)

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**Author:** [@OMLA](https://discourse.julialang.org/u/OMLA)\
**Replies:** 0\
**Last updated:** [August 6, 2021, 10:40am UTC](https://discourse.julialang.org/t/ann-easyml-jl-v0-2-0-a-foolproof-way-of-doing-ml-with-gui-elements/65936 "2021-08-06T10:40:24Z")

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A new version of EasyML.jl has been released. With our package it is possible to: Design a neural network Train a neural network Validate a neural network Apply a neural network to new data Classific…

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## [Concrete Example 0805: how to prevent using global variable in the module?](https://discourse.julialang.org/t/concrete-example-0805-how-to-prevent-using-global-variable-in-the-module/65917)

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**Author:** [@CRquantum](https://discourse.julialang.org/u/CRquantum)\
**Replies:** 6\
**Last updated:** [August 6, 2021, 10:50am UTC](https://discourse.julialang.org/t/concrete-example-0805-how-to-prevent-using-global-variable-in-the-module/65917 "2021-08-06T10:50:08Z")

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I learned from all of you that Julia discourage global variable. Thank you very much indeed! I am translating my Fortran code to Julia. It is a Monte Carlo parametric expectation maximization code. Basically using gauss…

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## [SplitODEProblem efficiency against classical ODEProblem](https://discourse.julialang.org/t/splitodeproblem-efficiency-against-classical-odeproblem/65232)

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**Author:** [@albertomercurio](https://discourse.julialang.org/u/albertomercurio)\
**Replies:** 4\
**Last updated:** [August 6, 2021, 10:34am UTC](https://discourse.julialang.org/t/splitodeproblem-efficiency-against-classical-odeproblem/65232 "2021-08-06T10:34:38Z")

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Hello, I read the documentation of the DifferentialEquations.jl package. I had an ODE problem where the RHS is f(u, p, t) = ( L + L(t) ) \* u, where L and L(t) are two sparse matrices (usually 600x600 matrix with a lot …

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## [Explicitly declaring the ODE Jacobian being less efficiently](https://discourse.julialang.org/t/explicitly-declaring-the-ode-jacobian-being-less-efficiently/65045)

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**Author:** [@Caique\_Rodrigues](https://discourse.julialang.org/u/Caique_Rodrigues)\
**Replies:** 16\
**Last updated:** [August 6, 2021, 10:22am UTC](https://discourse.julialang.org/t/explicitly-declaring-the-ode-jacobian-being-less-efficiently/65045 "2021-08-06T10:22:50Z")

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One of the problems that I am solving, without explicitly declaring the jacobian, was being solved in, roughly, 800 seconds. It isn’t that fast, the system is really stiff, but I am trying to optimize it as far as I can.…

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## [ModelingToolkit performance issue with repeated evaluations of variables in system of equations](https://discourse.julialang.org/t/modelingtoolkit-performance-issue-with-repeated-evaluations-of-variables-in-system-of-equations/64890)

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**Author:** [@ograsdijk](https://discourse.julialang.org/u/ograsdijk)\
**Replies:** 3\
**Last updated:** [August 6, 2021, 10:21am UTC](https://discourse.julialang.org/t/modelingtoolkit-performance-issue-with-repeated-evaluations-of-variables-in-system-of-equations/64890 "2021-08-06T10:21:20Z")

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Solving an ODEProblem created from an ODESystem with ModelingToolkit is slow when a simple time dependent variable (e.g. sin(t)) is added to the system of equations. For example: using ModelingToolkit using Differentia…

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## [Should there be a \`mapfilter\` function or macro?](https://discourse.julialang.org/t/should-there-be-a-mapfilter-function-or-macro/65933)

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**Author:** [@jules](https://discourse.julialang.org/u/jules)\
**Replies:** 5\
**Last updated:** [August 6, 2021, 10:18am UTC](https://discourse.julialang.org/t/should-there-be-a-mapfilter-function-or-macro/65933 "2021-08-06T10:18:58Z")

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I often encounter a scenario, where I use map but then notice in the body of the closure that I want to throw away some values. I think there’s no simple way to do this. Here’s a mockup version: itr = 1:100 mapfilter(it…

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## [Is multi-threading in Julia more like openMP or MPI?](https://discourse.julialang.org/t/is-multi-threading-in-julia-more-like-openmp-or-mpi/65930)

<div class="topic-metadata">

**Author:** [@CRquantum](https://discourse.julialang.org/u/CRquantum)\
**Replies:** 2\
**Last updated:** [August 6, 2021, 9:30am UTC](https://discourse.julialang.org/t/is-multi-threading-in-julia-more-like-openmp-or-mpi/65930 "2021-08-06T09:30:44Z")

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It is very beneficial to talk with you guys about Julia. I noticed that when you guys talking about prevent using global variables, many of you repeatedly mentioned that it can be thread safe not to use global variable. …

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## [Any implementation of 'Fixed smooth convolutional layer for avoiding checkerboard artifacts in CNNs'?](https://discourse.julialang.org/t/any-implementation-of-fixed-smooth-convolutional-layer-for-avoiding-checkerboard-artifacts-in-cnns/65881)

<div class="topic-metadata">

**Author:** [@czexana](https://discourse.julialang.org/u/czexana)\
**Replies:** 2\
**Last updated:** [August 6, 2021, 9:10am UTC](https://discourse.julialang.org/t/any-implementation-of-fixed-smooth-convolutional-layer-for-avoiding-checkerboard-artifacts-in-cnns/65881 "2021-08-06T09:10:54Z")

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Hello, I’m wondering if anyone has implemented the above paper, found at \[2002.02117\] Fixed smooth convolutional layer for avoiding checkerboard artifacts in CNNs that purports to fix checkerboard artifacts in conv and …

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