# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1726

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

**Page:** 1727

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## [Dependency Struggle in Local Registry](https://discourse.julialang.org/t/dependency-struggle-in-local-registry/40570)

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**Author:** [@cortner](https://discourse.julialang.org/u/cortner)\
**Replies:** 4\
**Last updated:** [June 6, 2020, 9:11pm UTC](https://discourse.julialang.org/t/dependency-struggle-in-local-registry/40570 "2020-06-06T21:11:30Z")

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I’m part of a small group maintaining our own registry for packages that are too specialised or not mature enough for General. Occasionally there are hiccups in managing dependencies, and here is another one - I hope som…

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## [Move Spines in 3d Pyplot](https://discourse.julialang.org/t/move-spines-in-3d-pyplot/40888)

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**Author:** [@Jojo\_Dad](https://discourse.julialang.org/u/Jojo_Dad)\
**Replies:** 1\
**Last updated:** [June 6, 2020, 8:04pm UTC](https://discourse.julialang.org/t/move-spines-in-3d-pyplot/40888 "2020-06-06T20:04:13Z")

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The following code is translated from Python where the last three lines move the spines: t = 0:0.1:2π x = sin.(t); y = cos.(t); fig=figure() using3D() ax = fig.add\_subplot(111,projection="3d") ax.plot(x,y,t); ax.xaxi…

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## [Passing a local to @cfunction fails](https://discourse.julialang.org/t/passing-a-local-to-cfunction-fails/40815)

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**Author:** [@nabla](https://discourse.julialang.org/u/nabla)\
**Replies:** 6\
**Last updated:** [June 6, 2020, 8:01pm UTC](https://discourse.julialang.org/t/passing-a-local-to-cfunction-fails/40815 "2020-06-06T20:01:59Z")

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I want to pass a local function via @cfunction to a library, but can’t do it. (This function is a callback, and should store some data as it’s called). Minimal non-working example of what I would like: const badlocalda…

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## [Linear Algebra with custom scalar product](https://discourse.julialang.org/t/linear-algebra-with-custom-scalar-product/40836)

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**Author:** [@Mikhail\_Kagalenko](https://discourse.julialang.org/u/Mikhail_Kagalenko)\
**Replies:** 7\
**Last updated:** [June 6, 2020, 6:33pm UTC](https://discourse.julialang.org/t/linear-algebra-with-custom-scalar-product/40836 "2020-06-06T18:33:01Z")

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Borrowing an example from the popular talk, let’s say I want to use LinearAlgebra.qr() , but with three-argument dot() introduced in Julia 1.4. So I need to define my own CustomVector that carries within it the middle ar…

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## [How to manage Julia Projects](https://discourse.julialang.org/t/how-to-manage-julia-projects/40868)

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**Author:** [@Janssena](https://discourse.julialang.org/u/Janssena)\
**Replies:** 3\
**Last updated:** [June 6, 2020, 5:10pm UTC](https://discourse.julialang.org/t/how-to-manage-julia-projects/40868 "2020-06-06T17:10:42Z")

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Hey all, I’ve recently started digging into Julia and am trying to implement some of my Python projects in Julia in order to get used to the language (these are mainly data science related projects). There is a lot I li…

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## [Specifying a branch of a package in Project.toml](https://discourse.julialang.org/t/specifying-a-branch-of-a-package-in-project-toml/32101)

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**Author:** [@Sheemon7](https://discourse.julialang.org/u/Sheemon7)\
**Replies:** 2\
**Last updated:** [June 6, 2020, 5:00pm UTC](https://discourse.julialang.org/t/specifying-a-branch-of-a-package-in-project-toml/32101 "2020-06-06T17:00:36Z")

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Is it possible to force a specific development branch of a package in Project.toml file?

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## [Using the groupby function](https://discourse.julialang.org/t/using-the-groupby-function/40839)

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**Author:** [@Chris\_Anderson](https://discourse.julialang.org/u/Chris_Anderson)\
**Replies:** 12\
**Last updated:** [June 6, 2020, 4:12pm UTC](https://discourse.julialang.org/t/using-the-groupby-function/40839 "2020-06-06T16:12:33Z")

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I have a dataframe that I would like to group by a categorical variable (4 values, let’s say a, b, c and d) and then by a continuous variable (values between 0 and 40). I’d like the continuous variable to be in groups t…

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## [Reducing BitArray with xor](https://discourse.julialang.org/t/reducing-bitarray-with-xor/20354)

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**Author:** [@ethomag](https://discourse.julialang.org/u/ethomag)\
**Replies:** 5\
**Last updated:** [June 6, 2020, 3:26pm UTC](https://discourse.julialang.org/t/reducing-bitarray-with-xor/20354 "2020-06-06T15:26:37Z")

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I am trying to xor a number of BitArray{1} vectors julia\> a=BitArray(\[1 1;1 0\]) 2×2 BitArray{2}: true true true false julia\> reduce(⊻, a, dims=1) ERROR: MethodError: no method matching reducedim\_init(::typeof(id…

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## [AOT Compiling? Performance Comparison](https://discourse.julialang.org/t/aot-compiling-performance-comparison/40870)

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**Author:** [@ok\_ok](https://discourse.julialang.org/u/ok_ok)\
**Replies:** 3\
**Last updated:** [June 6, 2020, 3:08pm UTC](https://discourse.julialang.org/t/aot-compiling-performance-comparison/40870 "2020-06-06T15:08:08Z")

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Hello Guys, i want to make a Comparison between OOP and Functional Programming. For my Performance Part i wrote an Algorithm in C++ which can run on N threads. I want to write the same code (the logic behind) in Julia a…

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## [RMSprop and Early stopping in Flux.jl](https://discourse.julialang.org/t/rmsprop-and-early-stopping-in-flux-jl/21065)

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**Author:** [@charlesll](https://discourse.julialang.org/u/charlesll)\
**Replies:** 8\
**Last updated:** [June 6, 2020, 2:57pm UTC](https://discourse.julialang.org/t/rmsprop-and-early-stopping-in-flux-jl/21065 "2020-06-06T14:57:19Z")

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Hi, I’m playing with Flux.jl and results are really nice. At the moment, I would like to use the RMSprop solver with Early Stopping. Anyone have experience with implementing those in Flux? Thanks!

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## [Trying to write a parallel for loop in Julia](https://discourse.julialang.org/t/trying-to-write-a-parallel-for-loop-in-julia/40862)

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**Author:** [@jbpatzer](https://discourse.julialang.org/u/jbpatzer)\
**Replies:** 2\
**Last updated:** [June 6, 2020, 2:06pm UTC](https://discourse.julialang.org/t/trying-to-write-a-parallel-for-loop-in-julia/40862 "2020-06-06T14:06:28Z")

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I’m new to both Julia and parallel computing and am currently trying to convert some MATLAB code that uses a parfor loop. I’m struggling with how to do this in Julia. I have read that pmap is what I need, as I have a par…

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## [Weird result in power operator](https://discourse.julialang.org/t/weird-result-in-power-operator/20824)

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**Author:** [@hesampour](https://discourse.julialang.org/u/hesampour)\
**Replies:** 13\
**Last updated:** [June 6, 2020, 1:19pm UTC](https://discourse.julialang.org/t/weird-result-in-power-operator/20824 "2020-06-06T13:19:55Z")

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hi there is a non stable result in power operator. this is the example. when I call the power with the variable the power not works. but when calling directly it julia\> a = -1.9345e6 -1.9345e6 julia\> a^1.5 ERROR: Do…

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## [Interrupt fails on Windows/Juno - enabling powershell does not help](https://discourse.julialang.org/t/interrupt-fails-on-windows-juno-enabling-powershell-does-not-help/40871)

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**Author:** [@egcjm](https://discourse.julialang.org/u/egcjm)\
**Replies:** 0\
**Last updated:** [June 6, 2020, 1:06pm UTC](https://discourse.julialang.org/t/interrupt-fails-on-windows-juno-enabling-powershell-does-not-help/40871 "2020-06-06T13:06:55Z")

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When I attempt to interrupt Julia in Juno on Windows, i get the message “Uncaught Error: Signals not supported on windows”, and “The error was thrown from the julia-client package. This issue has already been reported.…

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## [Problem in saving plot when giving color parameter](https://discourse.julialang.org/t/problem-in-saving-plot-when-giving-color-parameter/40855)

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**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 0\
**Last updated:** [June 6, 2020, 8:47am UTC](https://discourse.julialang.org/t/problem-in-saving-plot-when-giving-color-parameter/40855 "2020-06-06T08:47:44Z")

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Hello, I could save a plot using PyPlot, but when I added the custom colour parameter, I could not save the figure anymore: clf() myPlot = plot(soln.t, getindex.(soln.u, 1), soln.t, getindex.(soln.u, 2), …

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## [How to convert a symbol to a string of variable it represent](https://discourse.julialang.org/t/how-to-convert-a-symbol-to-a-string-of-variable-it-represent/40846)

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**Author:** [@StevenSiew](https://discourse.julialang.org/u/StevenSiew)\
**Replies:** 9\
**Last updated:** [June 6, 2020, 8:06am UTC](https://discourse.julialang.org/t/how-to-convert-a-symbol-to-a-string-of-variable-it-represent/40846 "2020-06-06T08:06:39Z")

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julia\> expr = :a + 3 \* :b :a + 3:b julia\> string(expr) ":a + 3:b" How do I convert an expression with symbols in it to a string representing the variables that the symbol represent? I want “a + 3 b” instead of “:a + 3…

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## [There is a \`f(g) = function(args...) broadcast(g, args...) end\` in \`Base\`?](https://discourse.julialang.org/t/there-is-a-f-g-function-args-broadcast-g-args-end-in-base/40841)

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**Author:** [@Henrique\_Becker](https://discourse.julialang.org/u/Henrique_Becker)\
**Replies:** 3\
**Last updated:** [June 6, 2020, 2:47am UTC](https://discourse.julialang.org/t/there-is-a-f-g-function-args-broadcast-g-args-end-in-base/40841 "2020-06-06T02:47:30Z")

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I know I can define a function like: wrap\_in\_broadcast(f) = function (args...) broadcast(f, args...) end I defined this function because many times I need to pass a function to another function, or use ∘ over a bro…

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## [Problem with loops or to modify the argumments of a function](https://discourse.julialang.org/t/problem-with-loops-or-to-modify-the-argumments-of-a-function/40834)

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**Author:** [@Josa9321](https://discourse.julialang.org/u/Josa9321)\
**Replies:** 6\
**Last updated:** [June 6, 2020, 12:21am UTC](https://discourse.julialang.org/t/problem-with-loops-or-to-modify-the-argumments-of-a-function/40834 "2020-06-06T00:21:53Z")

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I’m coding a Genetic Algorithm. When i put: new\_generation = \[crossing(population\[p\[1\]\], population\[p\[2\]\]) for p in parents\] My code works just fine, but I think that line, always declaring a new vector to every iterat…

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## [Problem with distributed, @everywhere using gives error on workers](https://discourse.julialang.org/t/problem-with-distributed-everywhere-using-gives-error-on-workers/40790)

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**Author:** [@pjentsch0](https://discourse.julialang.org/u/pjentsch0)\
**Replies:** 7\
**Last updated:** [June 5, 2020, 11:55pm UTC](https://discourse.julialang.org/t/problem-with-distributed-everywhere-using-gives-error-on-workers/40790 "2020-06-05T23:55:10Z")

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julia\> using MuladdMacro julia\> @everywhere using MuladdMacro ERROR: On worker 2: ArgumentError: Package MuladdMacro not found in current path: - Run \`import Pkg; Pkg.add("MuladdMacro")\` to install the MuladdMacro packa…

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## [Can I add multiple package's SnoopCompile precompile scripts to one?](https://discourse.julialang.org/t/can-i-add-multiple-packages-snoopcompile-precompile-scripts-to-one/40832)

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**Author:** [@marius311](https://discourse.julialang.org/u/marius311)\
**Replies:** 3\
**Last updated:** [June 5, 2020, 11:27pm UTC](https://discourse.julialang.org/t/can-i-add-multiple-packages-snoopcompile-precompile-scripts-to-one/40832 "2020-06-05T23:27:42Z")

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I’m trying to better understand SnoopCompile. It seems @snooping on my package creates alot of precompile statements in other modules, and my gut feeling is that for my case these are the really important ones in terms o…

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## [KrylovKit package installation hangs indefinitely](https://discourse.julialang.org/t/krylovkit-package-installation-hangs-indefinitely/37565)

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**Author:** [@iamsuddhasattwa](https://discourse.julialang.org/u/iamsuddhasattwa)\
**Replies:** 1\
**Last updated:** [June 5, 2020, 11:25pm UTC](https://discourse.julialang.org/t/krylovkit-package-installation-hangs-indefinitely/37565 "2020-06-05T23:25:51Z")

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Hi, when I try to install the KrylovKit package on my Windows computer, the execution stops indefinitely. julia\> using Pkg julia\> Pkg.add("KrylovKit”); The problem seems to be just about this package, as I was able to …

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## [JuMP 0.21: how to efficiently delete non-binding constraints in an LP?](https://discourse.julialang.org/t/jump-0-21-how-to-efficiently-delete-non-binding-constraints-in-an-lp/40650)

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**Author:** [@mike\_k](https://discourse.julialang.org/u/mike_k)\
**Replies:** 5\
**Last updated:** [June 5, 2020, 9:58pm UTC](https://discourse.julialang.org/t/jump-0-21-how-to-efficiently-delete-non-binding-constraints-in-an-lp/40650 "2020-06-05T21:58:46Z")

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Dear folks, I like to delete non-binding constraints in an LP, i.e., constraints with zero shadow price, and then re-optimize. I tried: optimize!( model ) if has\_duals( model ) num\_cons = num\_constraints(model, Gen…

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## [Tidying data: DataFrame](https://discourse.julialang.org/t/tidying-data-dataframe/40692)

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**Author:** [@Auhen\_Shauchuk](https://discourse.julialang.org/u/Auhen_Shauchuk)\
**Replies:** 12\
**Last updated:** [June 5, 2020, 9:38pm UTC](https://discourse.julialang.org/t/tidying-data-dataframe/40692 "2020-06-05T21:38:40Z")

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Hello, I have been trying to do some basic Data Analysis with Julia DataFrames and cannot find a way to tidy my data. I would like to simply use values of one of the columns to group df based on them and later plot. My …

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## [Julia programming on Eclipse Photon](https://discourse.julialang.org/t/julia-programming-on-eclipse-photon/15778)

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**Author:** [@Luis\_de\_Sousa](https://discourse.julialang.org/u/Luis_de_Sousa)\
**Replies:** 13\
**Last updated:** [June 5, 2020, 8:49pm UTC](https://discourse.julialang.org/t/julia-programming-on-eclipse-photon/15778 "2020-06-05T20:49:44Z")

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Hi everyone, I am taking the first steps with Julia. I do almost everything on Eclipse and would also like to program in Julia with it. There is an old plug-in called JuliaDT, but currently it is unusable. Are there ot…

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## [When I open Atom, I immediately receive this error](https://discourse.julialang.org/t/when-i-open-atom-i-immediately-receive-this-error/40828)

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**Author:** [@zyazdani](https://discourse.julialang.org/u/zyazdani)\
**Replies:** 3\
**Last updated:** [June 5, 2020, 8:46pm UTC](https://discourse.julialang.org/t/when-i-open-atom-i-immediately-receive-this-error/40828 "2020-06-05T20:46:39Z")

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Hi I’ve uninstalled and reinstalled Julia, Atom, as well as the packages uber-juno and julia-client. But upon opening atom I receive this error message. I think the error stems from a failed installation of juno. The ef…

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## [New Julia User Cannot Add any Packages](https://discourse.julialang.org/t/new-julia-user-cannot-add-any-packages/40365)

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**Author:** [@CosmoProf](https://discourse.julialang.org/u/CosmoProf)\
**Replies:** 13\
**Last updated:** [June 5, 2020, 8:19pm UTC](https://discourse.julialang.org/t/new-julia-user-cannot-add-any-packages/40365 "2020-06-05T20:19:35Z")

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Hi, I’ve tried installing Julia on multiple computer systems, and I keep getting error messages whenever I try to add any packages. Everything seems to go wrong after downloading “MbedTLS”, I tried methods suggested all…

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## [Writing complex Flux Models](https://discourse.julialang.org/t/writing-complex-flux-models/40439)

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**Author:** [@irhum](https://discourse.julialang.org/u/irhum)\
**Replies:** 4\
**Last updated:** [June 5, 2020, 7:14pm UTC](https://discourse.julialang.org/t/writing-complex-flux-models/40439 "2020-06-05T19:14:05Z")

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Flux’s typical go to when writing models is Chains, and for most feedforward models (with the occasional skip connection), with one input, it works quite beautifully. Problem is, when defining models as functions, we lo…

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## [Plotly not appearing in Jupyter Notebook](https://discourse.julialang.org/t/plotly-not-appearing-in-jupyter-notebook/31248)

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**Author:** [@JoeHD](https://discourse.julialang.org/u/JoeHD)\
**Replies:** 3\
**Last updated:** [June 5, 2020, 6:41pm UTC](https://discourse.julialang.org/t/plotly-not-appearing-in-jupyter-notebook/31248 "2020-06-05T18:41:59Z")

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Hi, I am running a Jupyter Notebook on an exercise that involved involved plotting, but I can’t seem to get that to work currently. Jupyter did successfully create the plot the first time I ran and installed the Plots p…

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## [Repeated assignments in Flux documentation](https://discourse.julialang.org/t/repeated-assignments-in-flux-documentation/40824)

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**Author:** [@natema](https://discourse.julialang.org/u/natema)\
**Replies:** 1\
**Last updated:** [June 5, 2020, 5:07pm UTC](https://discourse.julialang.org/t/repeated-assignments-in-flux-documentation/40824 "2020-06-05T17:07:39Z")

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In several examples of the Optimizer Reference section of the Flux docs, there is an assignment without arguments followed by the same assignment with arguments. For example, for Flux.Optimise.Descent we have opt = De…

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## [Package registrator web UI is down](https://discourse.julialang.org/t/package-registrator-web-ui-is-down/40813)

<div class="topic-metadata">

**Author:** [@anon37204545](https://discourse.julialang.org/u/anon37204545)\
**Replies:** 2\
**Last updated:** [June 5, 2020, 4:52pm UTC](https://discourse.julialang.org/t/package-registrator-web-ui-is-down/40813 "2020-06-05T16:52:14Z")

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https://pkg.julialang.org/registrator/ redirects to https://eu.pkg.julialang.org/registrator/ which throws a 404. Thus I cannot register a package via the web UI.

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## [Why can I not add methods to a function with a value?](https://discourse.julialang.org/t/why-can-i-not-add-methods-to-a-function-with-a-value/40819)

<div class="topic-metadata">

**Author:** [@derikk](https://discourse.julialang.org/u/derikk)\
**Replies:** 4\
**Last updated:** [June 5, 2020, 4:14pm UTC](https://discourse.julialang.org/t/why-can-i-not-add-methods-to-a-function-with-a-value/40819 "2020-06-05T16:14:18Z")

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I was trying to add a method to a function that accepts strings but not integers to convert integers to strings if necessary. For instance, given f = reverse, I get 16 methods, none of which apply to numerical types. N…

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