# General Usage

**URL:** https://discourse.julialang.org/c/usage/6.md?page=495

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**Page:** 496

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## [Package update / Unsatisfiable requirements](https://discourse.julialang.org/t/package-update-unsatisfiable-requirements/74745)

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**Author:** [@Bardo](https://discourse.julialang.org/u/Bardo)\
**Replies:** 1\
**Last updated:** [January 17, 2022, 1:46pm UTC](https://discourse.julialang.org/t/package-update-unsatisfiable-requirements/74745 "2022-01-17T13:46:48Z")

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I had an issue with Symbolics.jl and raised an issue. Turned out that Pkg.update() did not fetch the latest version, without further warning. julia\> Pkg.add(PackageSpec(name="Symbolics", version="4.3.0")) ... ERROR: Un…

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## [Should Documenter be part of Project.toml?](https://discourse.julialang.org/t/should-documenter-be-part-of-project-toml/73692)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 3\
**Last updated:** [January 17, 2022, 11:48am UTC](https://discourse.julialang.org/t/should-documenter-be-part-of-project-toml/73692 "2022-01-17T11:48:04Z")

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I have a main Project.toml, and a second one in the folder docs. I removed Documenter from the main Project.toml, but now I cannot build any longer the documentation locally, even though the Project.toml in the docs fol…

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## [Runtime (memory) on M1 Macbooks: something is not right](https://discourse.julialang.org/t/runtime-memory-on-m1-macbooks-something-is-not-right/74721)

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**Author:** [@Schneeschaufel](https://discourse.julialang.org/u/Schneeschaufel)\
**Replies:** 10\
**Last updated:** [January 17, 2022, 11:38am UTC](https://discourse.julialang.org/t/runtime-memory-on-m1-macbooks-something-is-not-right/74721 "2022-01-17T11:38:05Z")

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The following link: Trying to understand memory usage If I do this (see link above) on my Macbook 13" with M1 processor and 8GB RAM and SSD (Julia Rosetta Version 1.7.1 (2021-12-22)): julia\> using LinearAlgebra julia\> …

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## [Filter Dict()](https://discourse.julialang.org/t/filter-dict/22882)

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**Author:** [@yan25y](https://discourse.julialang.org/u/yan25y)\
**Replies:** 3\
**Last updated:** [August 24, 2021, 10:46am UTC](https://discourse.julialang.org/t/filter-dict/22882 "2021-08-24T10:46:38Z")

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I have a very basic question. When I was looking up how to filter values in Dict(), I came across this documentation What does p represent, and what do last(p) and first(p) mean?

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## [Test involving thread spawning failed in GitHub Actions](https://discourse.julialang.org/t/test-involving-thread-spawning-failed-in-github-actions/74731)

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**Author:** [@lucifer1004](https://discourse.julialang.org/u/lucifer1004)\
**Replies:** 1\
**Last updated:** [January 17, 2022, 5:21am UTC](https://discourse.julialang.org/t/test-involving-thread-spawning-failed-in-github-actions/74731 "2022-01-17T05:21:36Z")

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There is a test in my testset involving thread spawning. @test begin ... repl\_closed = Condition() start\_repl() = begin m.start\_repl(; output = output) notify(repl\_closed) end rep…

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## [Variables @over dimensions](https://discourse.julialang.org/t/variables-over-dimensions/74730)

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**Author:** [@Lincoln\_Hannah](https://discourse.julialang.org/u/Lincoln_Hannah)\
**Replies:** 2\
**Last updated:** [January 17, 2022, 4:42am UTC](https://discourse.julialang.org/t/variables-over-dimensions/74730 "2022-01-17T04:42:05Z")

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Does a package like this exist? Define variables @over dimensions / keys. System then creates the underlying DataFrames. PK-FK relationships remove the need for joins and lookup staetemnts. @over :X = 0:2 #…

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## [Pluto: highlighters in PrettyTables not working](https://discourse.julialang.org/t/pluto-highlighters-in-prettytables-not-working/73742)

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**Author:** [@VivMendes](https://discourse.julialang.org/u/VivMendes)\
**Replies:** 4\
**Last updated:** [January 16, 2022, 9:18pm UTC](https://discourse.julialang.org/t/pluto-highlighters-in-prettytables-not-working/73742 "2022-01-16T21:18:58Z")

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Hi, I am using Pluto. I have a matrix, and I want to highlight some of its entries using highlighters in PrettyTables. I can get the matrix printed out in the REPL, but unfortunately, the highlighters seem to be not wor…

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## [Output\_padding and Padding\_mode not found in ConvTranspose function](https://discourse.julialang.org/t/output-padding-and-padding-mode-not-found-in-convtranspose-function/74713)

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**Author:** [@Emory\_Raphael](https://discourse.julialang.org/u/Emory_Raphael)\
**Replies:** 0\
**Last updated:** [January 16, 2022, 6:37pm UTC](https://discourse.julialang.org/t/output-padding-and-padding-mode-not-found-in-convtranspose-function/74713 "2022-01-16T18:37:36Z")

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Hi, I am attempting to reimplement a version of CycleGan from pytorch to julia. But I have a doubt about how to use a package from Flux. Looking at the example code from Pytorch, there is a property in ConvTranspose2d c…

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## [Julia vs Zig surprise](https://discourse.julialang.org/t/julia-vs-zig-surprise/74540)

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**Author:** [@Bardo](https://discourse.julialang.org/u/Bardo)\
**Replies:** 16\
**Last updated:** [January 16, 2022, 4:29pm UTC](https://discourse.julialang.org/t/julia-vs-zig-surprise/74540 "2022-01-16T16:29:38Z")

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Recently ran into two performance comparisons including Julia. THE LINEAR ALGEBRA MAPPING PROBLEM. CURRENT STATE OF LINEAR ALGEBRA LANGUAGES AND LIBRARIES. shows that using BLAS for dense matrix operations, all librar…

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## [Julia TagBot app deprecation warning out of date](https://discourse.julialang.org/t/julia-tagbot-app-deprecation-warning-out-of-date/66141)

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**Author:** [@jlapeyre](https://discourse.julialang.org/u/jlapeyre)\
**Replies:** 2\
**Last updated:** [January 16, 2022, 2:44pm UTC](https://discourse.julialang.org/t/julia-tagbot-app-deprecation-warning-out-of-date/66141 "2022-01-16T14:44:09Z")

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go to a Julia package github repo. 2. click Settings. 3 click integrations. 4. click Configure on Julia TagBot. The resulting deprecation warning points to a discourse post that includes a TagBot.yml file. But, this fi…

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## [Using TagBot without the registry](https://discourse.julialang.org/t/using-tagbot-without-the-registry/63528)

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**Author:** [@cadojo](https://discourse.julialang.org/u/cadojo)\
**Replies:** 0\
**Last updated:** [June 25, 2021, 4:43am UTC](https://discourse.julialang.org/t/using-tagbot-without-the-registry/63528 "2021-06-25T04:43:08Z")

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I’d like to release versions of my package on GitHub without registering it with Julia’s registry. Ideally, I could commit a version change to my project’s Project.toml, and I’d have a GitHub Action that checks periodica…

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## [Type stability with variable arguments](https://discourse.julialang.org/t/type-stability-with-variable-arguments/74640)

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**Author:** [@atteson](https://discourse.julialang.org/u/atteson)\
**Replies:** 16\
**Last updated:** [January 16, 2022, 12:07am UTC](https://discourse.julialang.org/t/type-stability-with-variable-arguments/74640 "2022-01-16T00:07:54Z")

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Is there a way to maintain type stability with variable arguments? Below is some simplified code illustrating the issue. I’d like f(x,y,z) to perform like g(x,y,z): function f( args... ) s = 0.0 for arg in arg…

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## [Application of MPC to an existing code of 1-Dimensional heat equation](https://discourse.julialang.org/t/application-of-mpc-to-an-existing-code-of-1-dimensional-heat-equation/74679)

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**Author:** [@krusharth.shah](https://discourse.julialang.org/u/krusharth.shah)\
**Replies:** 0\
**Last updated:** [January 15, 2022, 6:06pm UTC](https://discourse.julialang.org/t/application-of-mpc-to-an-existing-code-of-1-dimensional-heat-equation/74679 "2022-01-15T18:06:38Z")

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Hello Julia community. I am working on a heat equation of 1D heat rod on which I want to apply the Model Predictive Controller. I have pasted my edited code with this message. I wanted some help to how can I solve the er…

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## [Precompiling Plots LoadError Display not defined](https://discourse.julialang.org/t/precompiling-plots-loaderror-display-not-defined/74661)

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**Author:** [@fadil](https://discourse.julialang.org/u/fadil)\
**Replies:** 0\
**Last updated:** [January 15, 2022, 11:35am UTC](https://discourse.julialang.org/t/precompiling-plots-loaderror-display-not-defined/74661 "2022-01-15T11:35:21Z")

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I used Plots successfully. But now, when writing using Plots, I get the error: \[ Info: Precompiling Plots \[91a5bcdd-55d7-5caf-9e0b-520d859cae80\] ERROR: LoadError: UndefVarError: Display not defined What to do?

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## [Create histogram with missing values](https://discourse.julialang.org/t/create-histogram-with-missing-values/74617)

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**Author:** [@Norbert-droid](https://discourse.julialang.org/u/Norbert-droid)\
**Replies:** 6\
**Last updated:** [January 15, 2022, 8:20am UTC](https://discourse.julialang.org/t/create-histogram-with-missing-values/74617 "2022-01-15T08:20:53Z")

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I want to make a histogram with the data in a column of a data frame; the column has a lot of missing values. I don’t want to drop the missing values in the data frame or create a new array without missing values. How do…

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## [Why is BitArray so slow?](https://discourse.julialang.org/t/why-is-bitarray-so-slow/14383)

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**Author:** [@mbeach42](https://discourse.julialang.org/u/mbeach42)\
**Replies:** 28\
**Last updated:** [January 14, 2022, 10:43pm UTC](https://discourse.julialang.org/t/why-is-bitarray-so-slow/14383 "2022-01-14T22:43:46Z")

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I was playing around with flipping numbers of an array, and I was surprised that doing so with BitArrays is much slower. I think the code below is pretty clear, using BenchmarkTools using Random a = rand(-1:2:1, 26, 11…

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## [Julia Thread Affinity not persistent when calling MKL function](https://discourse.julialang.org/t/julia-thread-affinity-not-persistent-when-calling-mkl-function/74560)

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**Author:** [@carstenbauer](https://discourse.julialang.org/u/carstenbauer)\
**Replies:** 2\
**Last updated:** [January 14, 2022, 8:10pm UTC](https://discourse.julialang.org/t/julia-thread-affinity-not-persistent-when-calling-mkl-function/74560 "2022-01-14T20:10:45Z")

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I observe a subtle issue where the pinning of Julia threads to specific cores is spoiled massively by running a seemingly harmless computation. By spoiled I mean that after running the computation all threads are pinned …

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## [3D object rotation in Makie doesn't seem to work well on wide aspect ratio monitors](https://discourse.julialang.org/t/3d-object-rotation-in-makie-doesnt-seem-to-work-well-on-wide-aspect-ratio-monitors/74582)

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**Author:** [@brianguenter](https://discourse.julialang.org/u/brianguenter)\
**Replies:** 2\
**Last updated:** [January 14, 2022, 7:58pm UTC](https://discourse.julialang.org/t/3d-object-rotation-in-makie-doesnt-seem-to-work-well-on-wide-aspect-ratio-monitors/74582 "2022-01-14T19:58:16Z")

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On my 21:9 aspect ratio monitor the rotation increment angle is so large that the teeniest movement of the mouse makes the object rotate by such a large angle that it is impossible to orient objects the way you want them…

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## [Why am I getting OutOfMemoryError() and how do I avoid it?](https://discourse.julialang.org/t/why-am-i-getting-outofmemoryerror-and-how-do-i-avoid-it/74639)

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**Author:** [@Soldalma](https://discourse.julialang.org/u/Soldalma)\
**Replies:** 4\
**Last updated:** [January 14, 2022, 7:26pm UTC](https://discourse.julialang.org/t/why-am-i-getting-outofmemoryerror-and-how-do-i-avoid-it/74639 "2022-01-14T19:26:14Z")

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I am trying to generate combinations of integers in the range from 1 to 12. Using 8 as an argument for the function below I get an OutOfMemory() error. The function works as expected for N \< 8. My PC has 32GB of memory o…

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## [Am I going about solving this PDE system the right way...?](https://discourse.julialang.org/t/am-i-going-about-solving-this-pde-system-the-right-way/74621)

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**Author:** [@Thaegy](https://discourse.julialang.org/u/Thaegy)\
**Replies:** 8\
**Last updated:** [January 14, 2022, 5:10pm UTC](https://discourse.julialang.org/t/am-i-going-about-solving-this-pde-system-the-right-way/74621 "2022-01-14T17:10:00Z")

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I have been transitioning my MATLAB code to Julia and managed to get working a sort of analogue to my MATLAB code. My PDE system has 2 coupled (1+1)D nonlinear PDEs: -\\mathrm{i}\\left(\\frac{\\partial \\psi}{\\partial X}\\r…

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## [Incorrect volume estimate in Qhull.jl](https://discourse.julialang.org/t/incorrect-volume-estimate-in-qhull-jl/74622)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 11\
**Last updated:** [January 14, 2022, 3:56pm UTC](https://discourse.julialang.org/t/incorrect-volume-estimate-in-qhull-jl/74622 "2022-01-14T15:56:32Z")

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I am trying to use QHull.jl to estimate the volume of points in high dimensional space. Unfortunately, some of the results from simple 2D examples seem to be in correct. Here is a MWE: using Plots, QHull, Random Rando…

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## [SQLite.jl NOT NULL constraint failed](https://discourse.julialang.org/t/sqlite-jl-not-null-constraint-failed/74628)

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**Author:** [@Jeremy](https://discourse.julialang.org/u/Jeremy)\
**Replies:** 0\
**Last updated:** [January 14, 2022, 2:52pm UTC](https://discourse.julialang.org/t/sqlite-jl-not-null-constraint-failed/74628 "2022-01-14T14:52:04Z")

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Since updating Julia from v1.6.2 (SQLite v1.2.0) to v1.7.1 (SQLite v 1.3.0) I get an error while trying to add data to an existing table in my database. julia\> dataBiomet |\> SQLite.load!(db,"Biomet") ERROR: SQLiteExcept…

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## [Benders Decomposition with callback](https://discourse.julialang.org/t/benders-decomposition-with-callback/74620)

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**Author:** [@ahmad88](https://discourse.julialang.org/u/ahmad88)\
**Replies:** 0\
**Last updated:** [January 14, 2022, 1:28pm UTC](https://discourse.julialang.org/t/benders-decomposition-with-callback/74620 "2022-01-14T13:28:53Z")

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I am trying to implement Benders Decomposition for a graph problem, I have a master problem and subproblem and in each iteration, I have to solve the master problem change the RHS of the subproblem constraint and solve t…

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## [Using Turing with ad-hoc likelihood](https://discourse.julialang.org/t/using-turing-with-ad-hoc-likelihood/74601)

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**Author:** [@Marco\_Lombardi](https://discourse.julialang.org/u/Marco_Lombardi)\
**Replies:** 1\
**Last updated:** [January 14, 2022, 12:57pm UTC](https://discourse.julialang.org/t/using-turing-with-ad-hoc-likelihood/74601 "2022-01-14T12:57:04Z")

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I am new to probabilistic programming an I would like to use Turing to perform statistical inference for a relatively complex physical problem, involving a specific model and a set of observations. The model has a few nu…

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## [Efficient conditional in-place assignment for arrays?](https://discourse.julialang.org/t/efficient-conditional-in-place-assignment-for-arrays/74593)

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**Author:** [@robsmith11](https://discourse.julialang.org/u/robsmith11)\
**Replies:** 7\
**Last updated:** [January 14, 2022, 12:26pm UTC](https://discourse.julialang.org/t/efficient-conditional-in-place-assignment-for-arrays/74593 "2022-01-14T12:26:29Z")

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Is there any way to the get the efficient assignment of f1 with the nicer syntax of f2? Something like a view or conditional SubArray? julia\> function f1!(xs) for i in eachindex(xs) if xs\[i\] \< 0.5 …

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## [Dictionary Initialization and Usage](https://discourse.julialang.org/t/dictionary-initialization-and-usage/74609)

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**Author:** [@Rajat\_Chaudhari](https://discourse.julialang.org/u/Rajat_Chaudhari)\
**Replies:** 4\
**Last updated:** [January 14, 2022, 12:23pm UTC](https://discourse.julialang.org/t/dictionary-initialization-and-usage/74609 "2022-01-14T12:23:09Z")

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I started with Julia today and was experimenting with Dictionary feature. The following is the code I wrote when I faced the error. Could anyone point out as to why such error is occuring and why such usage is wrong? …

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## [ROS C++ full package tutorial](https://discourse.julialang.org/t/ros-c-full-package-tutorial/74595)

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**Author:** [@kobied](https://discourse.julialang.org/u/kobied)\
**Replies:** 0\
**Last updated:** [January 14, 2022, 6:37am UTC](https://discourse.julialang.org/t/ros-c-full-package-tutorial/74595 "2022-01-14T06:37:56Z")

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Hi, i have been looking for a full tutorial on how to build a ros cpp package using ‘ROS.jl’ but couldn’t find one. Any one knows were i can find such tutorial?

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## [Reproducible simulations](https://discourse.julialang.org/t/reproducible-simulations/74589)

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**Author:** [@stephenll](https://discourse.julialang.org/u/stephenll)\
**Replies:** 3\
**Last updated:** [January 14, 2022, 6:09am UTC](https://discourse.julialang.org/t/reproducible-simulations/74589 "2022-01-14T06:09:41Z")

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At my job it is very important to have our algorithms be as close to reproducible as possible on different systems, no matter the number of cores. Even though, in my mind, it shouldn’t matter, the powers that be want th…

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## [Best practice for script with ARGS that can also be run with \`include\`](https://discourse.julialang.org/t/best-practice-for-script-with-args-that-can-also-be-run-with-include/74435)

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**Author:** [@goerz](https://discourse.julialang.org/u/goerz)\
**Replies:** 3\
**Last updated:** [January 14, 2022, 4:11am UTC](https://discourse.julialang.org/t/best-practice-for-script-with-args-that-can-also-be-run-with-include/74435 "2022-01-14T04:11:02Z")

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I’m trying to figure out a good pattern for writing scripts that take command line arguments, and that are easy to run both from the shell (julia script.jl), and from inside the REPL/another Julia script (via include). T…

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## [Why is \`TaskLocalRNG\` faster than \`Xoshiro\` with multiple threads?](https://discourse.julialang.org/t/why-is-tasklocalrng-faster-than-xoshiro-with-multiple-threads/74577)

<div class="topic-metadata">

**Author:** [@robsmith11](https://discourse.julialang.org/u/robsmith11)\
**Replies:** 7\
**Last updated:** [January 14, 2022, 3:58am UTC](https://discourse.julialang.org/t/why-is-tasklocalrng-faster-than-xoshiro-with-multiple-threads/74577 "2022-01-14T03:58:52Z")

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I was a bit confused by the docs: In a multi-threaded program, you should generally use different RNG objects from different threads or tasks in order to be thread-safe. However, the default RNG is thread-safe as of Ju…

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