# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1317

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

**Page:** 1318

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## [Applying performance tips in library](https://discourse.julialang.org/t/applying-performance-tips-in-library/65452)

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**Author:** [@rvignolo](https://discourse.julialang.org/u/rvignolo)\
**Replies:** 0\
**Last updated:** [July 28, 2021, 4:44pm UTC](https://discourse.julialang.org/t/applying-performance-tips-in-library/65452 "2021-07-28T16:44:37Z")

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Hi all, I have implemented a neutron transport particle code in julia, NeutronTransport.jl, and I want it to be as fast as possible. Specifically, I just wanted to know if someone is interested in helping me implement: …

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## [Line thickness, marker size scales in Makie](https://discourse.julialang.org/t/line-thickness-marker-size-scales-in-makie/65447)

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**Author:** [@keithjlee](https://discourse.julialang.org/u/keithjlee)\
**Replies:** 0\
**Last updated:** [July 28, 2021, 4:17pm UTC](https://discourse.julialang.org/t/line-thickness-marker-size-scales-in-makie/65447 "2021-07-28T16:17:35Z")

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I’m currently trying to make sense of how Makie (GLMakie) deals with scaling of element sizes. I’m trying to make a quick function that visualizes structures for finite element analysis, just simple points and lines tha…

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## [Data-formatting in and out of Flux ML model](https://discourse.julialang.org/t/data-formatting-in-and-out-of-flux-ml-model/65383)

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**Author:** [@amit1](https://discourse.julialang.org/u/amit1)\
**Replies:** 1\
**Last updated:** [July 28, 2021, 4:15pm UTC](https://discourse.julialang.org/t/data-formatting-in-and-out-of-flux-ml-model/65383 "2021-07-28T16:15:29Z")

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Hi, I am still learning the ropes of Flux framework. I have experience of tensorflow and bit of pytorch, but I am interested in Flux, mostly because of the flexibility and uniformity (no more to\_numpy and vice versa!). I…

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## [Scaling for multi-threading](https://discourse.julialang.org/t/scaling-for-multi-threading/65301)

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**Author:** [@francispoulin](https://discourse.julialang.org/u/francispoulin)\
**Replies:** 10\
**Last updated:** [July 28, 2021, 4:14pm UTC](https://discourse.julialang.org/t/scaling-for-multi-threading/65301 "2021-07-28T16:14:35Z")

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A question for @luraess and @samo . In the mini-course you gave here you give a lot of different code to solve the diffusion equation in 3D, which was a lot of fun. I know that you have shown that multi-GPU can be effic…

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## [Missing "1 - Strings.ipynb" in July 23, 2021 github update of JuliaAcademy / Introduction-to-Julia](https://discourse.julialang.org/t/missing-1-strings-ipynb-in-july-23-2021-github-update-of-juliaacademy-introduction-to-julia/65445)

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**Author:** [@Seawolf2913](https://discourse.julialang.org/u/Seawolf2913)\
**Replies:** 0\
**Last updated:** [July 28, 2021, 3:23pm UTC](https://discourse.julialang.org/t/missing-1-strings-ipynb-in-july-23-2021-github-update-of-juliaacademy-introduction-to-julia/65445 "2021-07-28T15:23:43Z")

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The “1 - Strings.ipynb” file is a copy of the “0 - Getting started.ipynb” file.

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## [Simple Dykstra projection : Could it be faster?](https://discourse.julialang.org/t/simple-dykstra-projection-could-it-be-faster/65432)

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**Author:** [@lrnv](https://discourse.julialang.org/u/lrnv)\
**Replies:** 5\
**Last updated:** [July 28, 2021, 3:19pm UTC](https://discourse.julialang.org/t/simple-dykstra-projection-could-it-be-faster/65432 "2021-07-28T15:19:51Z")

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Hi, I’m writting a simple Dykstra sheme for projecting a vector start onto equality constraints Ax = b and inequelity constraints x \>= 0. It works great, but I wander if it could be faster ? Here’s the current version …

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## [404 link for a graphs talk](https://discourse.julialang.org/t/404-link-for-a-graphs-talk/65440)

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**Author:** [@zvoulgaris](https://discourse.julialang.org/u/zvoulgaris)\
**Replies:** 5\
**Last updated:** [July 28, 2021, 2:46pm UTC](https://discourse.julialang.org/t/404-link-for-a-graphs-talk/65440 "2021-07-28T14:46:40Z")

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Great! If only all the sessions worked too, how great a conference it would be! I tried accessing the Graphs talk earlier and got a 404 error. Because I know you guys are doing your best, I decided not to mention this to…

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## [Surprising (?) behaviour of assignment-update operators](https://discourse.julialang.org/t/surprising-behaviour-of-assignment-update-operators/65431)

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**Author:** [@johnomotani](https://discourse.julialang.org/u/johnomotani)\
**Replies:** 8\
**Last updated:** [July 28, 2021, 1:57pm UTC](https://discourse.julialang.org/t/surprising-behaviour-of-assignment-update-operators/65431 "2021-07-28T13:57:29Z")

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It seems like f -= a is actually exactly equivalent to f = f - a. This surprised me because I’d naively expected -= to be update-in-place, so that I wouldn’t need a View when f is an Array slice, but actually it seems I …

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## [JuliaCon 2021 is Live](https://discourse.julialang.org/t/juliacon-2021-is-live/65434)

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**Author:** [@mbauman](https://discourse.julialang.org/u/mbauman)\
**Replies:** 0\
**Last updated:** [July 28, 2021, 12:53pm UTC](https://discourse.julialang.org/t/juliacon-2021-is-live/65434 "2021-07-28T12:53:27Z")

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JuliaCon 2021 is Live! If you haven’t done so yet, register for free today so you can more fully participate in the sessions. Find the complete schedule and more details at juliacon.org.

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## [Plot with x-axis in radians with ticks at multiples of pi](https://discourse.julialang.org/t/plot-with-x-axis-in-radians-with-ticks-at-multiples-of-pi/65325)

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**Author:** [@e3c6](https://discourse.julialang.org/u/e3c6)\
**Replies:** 3\
**Last updated:** [July 27, 2021, 8:33am UTC](https://discourse.julialang.org/t/plot-with-x-axis-in-radians-with-ticks-at-multiples-of-pi/65325 "2021-07-27T08:33:27Z")

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I have a plot where the x-axis is an angle in radians. Is there an easy way to make the ticks and the tick labels be multiples of pi? For example, I would like to obtain a figure like this:

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## [How to predict X given a set of Ys in Julia?](https://discourse.julialang.org/t/how-to-predict-x-given-a-set-of-ys-in-julia/64746)

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**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 21\
**Last updated:** [July 28, 2021, 1:31pm UTC](https://discourse.julialang.org/t/how-to-predict-x-given-a-set-of-ys-in-julia/64746 "2021-07-28T13:31:51Z")

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Hello, I have a vector V of y values describing a curve for a series of time points x; I have a threshold level Yt. How can I predict the exact x value for Yt? Essentially: how do I interpolate Y to find X in Julia? I…

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## [Why no \`last(::Generator)\`?](https://discourse.julialang.org/t/why-no-last-generator/65429)

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**Author:** [@jlbosse](https://discourse.julialang.org/u/jlbosse)\
**Replies:** 3\
**Last updated:** [July 28, 2021, 1:14pm UTC](https://discourse.julialang.org/t/why-no-last-generator/65429 "2021-07-28T13:14:32Z")

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Is there a good reason, why last is not implemented for Generators? I came up with function Base.last(iter::Base.Generator) x = last(iter.iter) return iter.f(i) end which does exactly what I would expect (and a…

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## [My ConstraintSolver.jl page](https://discourse.julialang.org/t/my-constraintsolver-jl-page/65430)

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**Author:** [@Hakan\_Kjellerstrand](https://discourse.julialang.org/u/Hakan_Kjellerstrand)\
**Replies:** 2\
**Last updated:** [July 28, 2021, 12:17pm UTC](https://discourse.julialang.org/t/my-constraintsolver-jl-page/65430 "2021-07-28T12:17:38Z")

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One of my (other) Julia-related interests is Ole Kröger’s Home · ConstraintSolver . My ConstraintSolver.jl models are here: My Julia ConstraintSolver.jl page , also available at https://github.com/hakank/hakank/tree/mas…

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## [How to dispatch by value?](https://discourse.julialang.org/t/how-to-dispatch-by-value/43266)

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**Author:** [@Bryan\_So](https://discourse.julialang.org/u/Bryan_So)\
**Replies:** 25\
**Last updated:** [July 28, 2021, 12:05pm UTC](https://discourse.julialang.org/t/how-to-dispatch-by-value/43266 "2021-07-28T12:05:15Z")

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Very beginner question about using “where” in function declaration. Is it possible to do something like this? function p(c::Structure) where c.id == :x do something now I know c.id == :x end function p(c::Struct…

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## [Why does broadcast operation allocate?](https://discourse.julialang.org/t/why-does-broadcast-operation-allocate/65428)

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**Author:** [@johnomotani](https://discourse.julialang.org/u/johnomotani)\
**Replies:** 3\
**Last updated:** [July 28, 2021, 11:06am UTC](https://discourse.julialang.org/t/why-does-broadcast-operation-allocate/65428 "2021-07-28T11:06:21Z")

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Why does this broadcasting allocate? julia\> a = rand(241); b = rand(241); julia\> @time a .-= b; 0.111315 seconds (188.85 k allocations: 11.037 MiB, 99.59% compilation time) julia\> @time a .-= b; 0.000016 seconds (…

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## [Converting a Time() to an standardized Int64 or Float64](https://discourse.julialang.org/t/converting-a-time-to-an-standardized-int64-or-float64/65404)

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**Author:** [@YummyPampers2](https://discourse.julialang.org/u/YummyPampers2)\
**Replies:** 7\
**Last updated:** [July 28, 2021, 9:11am UTC](https://discourse.julialang.org/t/converting-a-time-to-an-standardized-int64-or-float64/65404 "2021-07-28T09:11:06Z")

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Hello Everyone: I instantiated a variable using Sprints = Time(00,01,00):Dates.Minute(1):Time(01,00,00) and created a data frame with: Allstars = DataFrame(Id = 1:10, BestTimes = rand(Sprints, 10)) How could I conve…

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## [Changing Gtk widget border/background colors](https://discourse.julialang.org/t/changing-gtk-widget-border-background-colors/5126)

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**Author:** [@jpsamaroo](https://discourse.julialang.org/u/jpsamaroo)\
**Replies:** 3\
**Last updated:** [July 28, 2021, 8:40am UTC](https://discourse.julialang.org/t/changing-gtk-widget-border-background-colors/5126 "2021-07-28T08:40:15Z")

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I’m having a bit of difficulty trying to understand how one would set the background or border color of a widget with Gtk.jl. I’ve taken a look at this issue, but haven’t been able to make it work with Julia 0.6 and Gtk …

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## [Inter-registry dependencies](https://discourse.julialang.org/t/inter-registry-dependencies/56932)

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**Author:** [@wildart](https://discourse.julialang.org/u/wildart)\
**Replies:** 5\
**Last updated:** [July 28, 2021, 6:50am UTC](https://discourse.julialang.org/t/inter-registry-dependencies/56932 "2021-07-28T06:50:45Z")

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Current registry design does not allow to register packages that have dependencies registered in other registries. This limitation is circumvented for any package registered in General registry because this registry is t…

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## [Packages are not installed properly](https://discourse.julialang.org/t/packages-are-not-installed-properly/65414)

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**Author:** [@AnilChincholi](https://discourse.julialang.org/u/AnilChincholi)\
**Replies:** 0\
**Last updated:** [July 28, 2021, 6:13am UTC](https://discourse.julialang.org/t/packages-are-not-installed-properly/65414 "2021-07-28T06:13:24Z")

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When i try to add/install a package i am getting the error This happens for other packages also Can anyone suggest how can i resolve the issue ?

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## [Problem with \`@reduce\` of \`FLoops\`; data race?](https://discourse.julialang.org/t/problem-with-reduce-of-floops-data-race/65410)

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**Author:** [@HJW019](https://discourse.julialang.org/u/HJW019)\
**Replies:** 2\
**Last updated:** [July 28, 2021, 4:14am UTC](https://discourse.julialang.org/t/problem-with-reduce-of-floops-data-race/65410 "2021-07-28T04:14:58Z")

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I try to use multithreading in Julia and am aware of the data race issue. I then found that FLoops provides macros that seems to be able to guard against the problem. I nevertheless encountered a strange behavior with @r…

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## [Julia 1.6 Stacktrace](https://discourse.julialang.org/t/julia-1-6-stacktrace/57981)

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**Author:** [@Kruxigt](https://discourse.julialang.org/u/Kruxigt)\
**Replies:** 20\
**Last updated:** [July 28, 2021, 1:16am UTC](https://discourse.julialang.org/t/julia-1-6-stacktrace/57981 "2021-07-28T01:16:28Z")

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Hi good folks! I like the idea of trying to make the fairly cluttered stacktrace more readable by “syntax” highlighting. However, I don’t get the choices introduced in 1.6 at all. The filename and row number are probabl…

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## [Precise control of navigation in 3D scene in Makie?](https://discourse.julialang.org/t/precise-control-of-navigation-in-3d-scene-in-makie/62387)

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**Author:** [@hacklint](https://discourse.julialang.org/u/hacklint)\
**Replies:** 7\
**Last updated:** [July 27, 2021, 11:27pm UTC](https://discourse.julialang.org/t/precise-control-of-navigation-in-3d-scene-in-makie/62387 "2021-07-27T23:27:56Z")

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Hi, I’m starting to visualize a collection of meshes in Makie, currently using the mouse to navigate the content. However, after a while the rotate, drag and zoom performed usually make me end up with parts of the conte…

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## [Styling AlgebraOfGraphics boxplots](https://discourse.julialang.org/t/styling-algebraofgraphics-boxplots/65335)

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**Author:** [@jbmuir](https://discourse.julialang.org/u/jbmuir)\
**Replies:** 13\
**Last updated:** [July 27, 2021, 10:30pm UTC](https://discourse.julialang.org/t/styling-algebraofgraphics-boxplots/65335 "2021-07-27T22:30:53Z")

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I’m amazed how easy it is to make complex and good-looking figures using AlgebraOfGraphics - it is still a little opaque as to how to use custom styles in them though. I’d like to be able to change the colors in this…

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## [How to use LAPACK and BLAS for Julia 1.6.1 in UBUNTU 20.04](https://discourse.julialang.org/t/how-to-use-lapack-and-blas-for-julia-1-6-1-in-ubuntu-20-04/65396)

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**Author:** [@Aniruddha](https://discourse.julialang.org/u/Aniruddha)\
**Replies:** 1\
**Last updated:** [July 27, 2021, 9:54pm UTC](https://discourse.julialang.org/t/how-to-use-lapack-and-blas-for-julia-1-6-1-in-ubuntu-20-04/65396 "2021-07-27T21:54:48Z")

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I am getting the following error while trying to run the Extrusion function in the Gmsh package through Julia API: Error : LU factorization and substitution requires LAPACK I think in my system, Julia cannot initiate t…

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## [How to treat one of the function arguments as a constant during broadcasting](https://discourse.julialang.org/t/how-to-treat-one-of-the-function-arguments-as-a-constant-during-broadcasting/65391)

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**Author:** [@tonygem96](https://discourse.julialang.org/u/tonygem96)\
**Replies:** 4\
**Last updated:** [July 27, 2021, 9:08pm UTC](https://discourse.julialang.org/t/how-to-treat-one-of-the-function-arguments-as-a-constant-during-broadcasting/65391 "2021-07-27T21:08:13Z")

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I wonder what is the correct way to create objects that are iterable (or broadcastable?). The code below works as expected. struct A x::Float64 y::Float64 end function foo(n,m,s::A) u = n^2 + s.x^2 v = m + s.y return…

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## [Modify a dictionary under a new name modifies the original dictionary](https://discourse.julialang.org/t/modify-a-dictionary-under-a-new-name-modifies-the-original-dictionary/65398)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 6\
**Last updated:** [July 27, 2021, 8:00pm UTC](https://discourse.julialang.org/t/modify-a-dictionary-under-a-new-name-modifies-the-original-dictionary/65398 "2021-07-27T20:00:07Z")

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x=Dict( row=\> DataFrame( y=1) ) z=x push!(z, y=2) x gives me 1,2 How do I get it to only give me 1?

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## [Package growth tips and tricks: Creating an organization, triage, better management](https://discourse.julialang.org/t/package-growth-tips-and-tricks-creating-an-organization-triage-better-management/65167)

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**Author:** [@Wikunia](https://discourse.julialang.org/u/Wikunia)\
**Replies:** 8\
**Last updated:** [July 27, 2021, 7:50pm UTC](https://discourse.julialang.org/t/package-growth-tips-and-tricks-creating-an-organization-triage-better-management/65167 "2021-07-27T19:50:44Z")

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Hey everyone, about a year ago @TheCedarPrince and I created GitHub - JuliaAnimators/Javis.jl: Julia Animations and Visualizations as a small little project to create some neat little gifs. Well it grew a “bit” more th…

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## [Why does my devectorized code keep allocating memory?](https://discourse.julialang.org/t/why-does-my-devectorized-code-keep-allocating-memory/62727)

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**Author:** [@WouterJRV](https://discourse.julialang.org/u/WouterJRV)\
**Replies:** 14\
**Last updated:** [July 27, 2021, 6:50pm UTC](https://discourse.julialang.org/t/why-does-my-devectorized-code-keep-allocating-memory/62727 "2021-07-27T18:50:17Z")

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I am trying to solve a complex Ginzburg-Landau equation in Julia, defined by function CGLfun!(du,u,p,t) NBmat,gridsize,η,g,V,α,σ=p du.=1im\*(1 .-1im\*η).\*(NBmat\*u.-4\*u)/gridsize^2 +(.-(1im).\*V+α.-(σ.+1im\*g).\*abs2.(u))…

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## [Linear interpolation in 4D?](https://discourse.julialang.org/t/linear-interpolation-in-4d/65276)

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**Author:** [@marianoarnaiz](https://discourse.julialang.org/u/marianoarnaiz)\
**Replies:** 13\
**Last updated:** [July 27, 2021, 5:52pm UTC](https://discourse.julialang.org/t/linear-interpolation-in-4d/65276 "2021-07-27T17:52:01Z")

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Hi Forum! Yes, another question on interpolation. I have this 5D data that I need linearly interpolated (spline and quadratic are good, but I need to avoid any overshoot). If anyone os curios the data is something like…

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## [Adding a linear or logistic equation to a curve plot](https://discourse.julialang.org/t/adding-a-linear-or-logistic-equation-to-a-curve-plot/65348)

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**Author:** [@YummyPampers2](https://discourse.julialang.org/u/YummyPampers2)\
**Replies:** 3\
**Last updated:** [July 27, 2021, 5:50pm UTC](https://discourse.julialang.org/t/adding-a-linear-or-logistic-equation-to-a-curve-plot/65348 "2021-07-27T17:50:03Z")

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Hello Everyone: Is there an approach to displaying the regression equation on a curve plot? I would like to avoid using PyCall.jl or SciKitLearn.jl. I am using StatsPlots.jl with a PlotlyJS backend(). Initially, I …

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