# Latest

**URL:** https://discourse.julialang.org/latest.md?page=721

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

**Page:** 722

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## [Julia Plots compilation EXCEPTION\_ACCESS\_VIOLATION error on Windows](https://discourse.julialang.org/t/julia-plots-compilation-exception-access-violation-error-on-windows/97742)

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**Author:** [@RickardoMM](https://discourse.julialang.org/u/RickardoMM)\
**Replies:** 0\
**Last updated:** [April 21, 2023, 2:05pm UTC](https://discourse.julialang.org/t/julia-plots-compilation-exception-access-violation-error-on-windows/97742 "2023-04-21T14:05:29Z")

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I am using Julia 1.8.5 on Windows. I wanted to use the package Plots, which I was able to do in another PC, but in my current one the kernel dies whenever I try to plot anything. After reinstalling Plots and Julia, and p…

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## [Which is the error given by CompatHelper in GitHub and how to solve it?](https://discourse.julialang.org/t/which-is-the-error-given-by-compathelper-in-github-and-how-to-solve-it/97739)

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**Author:** [@martinmestre](https://discourse.julialang.org/u/martinmestre)\
**Replies:** 9\
**Last updated:** [April 21, 2023, 1:55pm UTC](https://discourse.julialang.org/t/which-is-the-error-given-by-compathelper-in-github-and-how-to-solve-it/97739 "2023-04-21T13:55:16Z")

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Hello, this is my first time with the great PkgTemplates package and interacting with GitHub repository. Apart from the title questions I would like to know how does CompatHelper work? Does it install all the packages i…

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## [Is this an expected behavior of rand.()?](https://discourse.julialang.org/t/is-this-an-expected-behavior-of-rand/97735)

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**Author:** [@ovt](https://discourse.julialang.org/u/ovt)\
**Replies:** 4\
**Last updated:** [April 21, 2023, 1:23pm UTC](https://discourse.julialang.org/t/is-this-an-expected-behavior-of-rand/97735 "2023-04-21T13:23:52Z")

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julia\> A = zeros(3,3) 3×3 Matrix{Float64}: 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 julia\> true ? A .= rand.() : nothing 3×3 Matrix{Float64}: 0.191487 0.0617435 0.279438 0.47524 0.467929 0.45603 0.212515 0…

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## [Julia function from non-Julia thread and pthread\_join](https://discourse.julialang.org/t/julia-function-from-non-julia-thread-and-pthread-join/97740)

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**Author:** [@jonas-kr](https://discourse.julialang.org/u/jonas-kr)\
**Replies:** 0\
**Last updated:** [April 21, 2023, 1:21pm UTC](https://discourse.julialang.org/t/julia-function-from-non-julia-thread-and-pthread-join/97740 "2023-04-21T13:21:19Z")

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Since 46609 has been merged, it has become possible to have non-Julia threads call Julia functions. Accordingly, I have set up the following MWE of a C++ library callback\_example compiled with g++ -shared -o callback\_exa…

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## [Help wanted with ppo implementation in flux.jl](https://discourse.julialang.org/t/help-wanted-with-ppo-implementation-in-flux-jl/97734)

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**Author:** [@aminmr1375](https://discourse.julialang.org/u/aminmr1375)\
**Replies:** 3\
**Last updated:** [April 21, 2023, 11:41am UTC](https://discourse.julialang.org/t/help-wanted-with-ppo-implementation-in-flux-jl/97734 "2023-04-21T11:41:38Z")

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my implementation works well for other environments but not working well at LunarLander-v2 (can’t reach to +200) it’s learning but doesn’t solve the env but works well on other envs like CartPole, Acrobot, also a custom…

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## [Delay Differential Equations does not provide any solution](https://discourse.julialang.org/t/delay-differential-equations-does-not-provide-any-solution/96769)

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**Author:** [@pclus](https://discourse.julialang.org/u/pclus)\
**Replies:** 7\
**Last updated:** [April 21, 2023, 10:22am UTC](https://discourse.julialang.org/t/delay-differential-equations-does-not-provide-any-solution/96769 "2023-04-21T10:22:44Z")

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I am trying to use DifferentialEquations.jl to solve a delay differential equation. However, I fail to reproduce the example provided in the documentation. I copy here the code of the example: using DifferentialEquatio…

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## [Should functions that take AbstractStrings also work for Symbols?](https://discourse.julialang.org/t/should-functions-that-take-abstractstrings-also-work-for-symbols/97687)

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**Author:** [@robsmith11](https://discourse.julialang.org/u/robsmith11)\
**Replies:** 4\
**Last updated:** [April 21, 2023, 9:34am UTC](https://discourse.julialang.org/t/should-functions-that-take-abstractstrings-also-work-for-symbols/97687 "2023-04-21T09:34:03Z")

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I often use Symbols for better efficiency in large DataFrames, but sometimes would still like to filter by calling functions on the value of the Symbols like contains, startswith, endswith, etc. or even length. Is there…

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## [Processing real-time streaming audio, controlled by a GUI](https://discourse.julialang.org/t/processing-real-time-streaming-audio-controlled-by-a-gui/96692)

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**Author:** [@cdevane](https://discourse.julialang.org/u/cdevane)\
**Replies:** 5\
**Last updated:** [April 21, 2023, 6:24am UTC](https://discourse.julialang.org/t/processing-real-time-streaming-audio-controlled-by-a-gui/96692 "2023-04-21T06:24:37Z")

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I’m a relative newcomer to Julia. I’d like to build an app that processes an audio stream in real time, with processing parameters controlled from a GUI. I’m looking for suggestions on how to approach this, or better ye…

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## [HTTP.jl async is slow compared to python+aiohttp](https://discourse.julialang.org/t/http-jl-async-is-slow-compared-to-python-aiohttp/96736)

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**Author:** [@agoodm](https://discourse.julialang.org/u/agoodm)\
**Replies:** 48\
**Last updated:** [April 21, 2023, 4:52am UTC](https://discourse.julialang.org/t/http-jl-async-is-slow-compared-to-python-aiohttp/96736 "2023-04-21T04:52:19Z")

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So @fabiangans and I have been having discussions about improving the performance of Zarr.jl. The goal is to improve the time it takes to load data from a remote zarr store (eg on HTTP, GCS, or S3). The current implement…

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## [Append a \`DataFrame\` to a partition of an existing \`ArrowTable\` without creating a new \`ArrowTable\`?](https://discourse.julialang.org/t/append-a-dataframe-to-a-partition-of-an-existing-arrowtable-without-creating-a-new-arrowtable/97461)

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**Author:** [@phantom](https://discourse.julialang.org/u/phantom)\
**Replies:** 7\
**Last updated:** [April 21, 2023, 1:28am UTC](https://discourse.julialang.org/t/append-a-dataframe-to-a-partition-of-an-existing-arrowtable-without-creating-a-new-arrowtable/97461 "2023-04-21T01:28:19Z")

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Hi! suppose I have the following GroupedDataFrame GDF1 = groupby(DataFrame(ID = \[ "Eng1", "Eng2"\] , Date = \[Date(2023,4,10),Date(2023,4,10)\], Time = \[3.85, 4.13\]), :ID) With Arrow.append I can save each subdataframe o…

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## [Macro for struct generation using symbolic parameters](https://discourse.julialang.org/t/macro-for-struct-generation-using-symbolic-parameters/97693)

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**Author:** [@bohm](https://discourse.julialang.org/u/bohm)\
**Replies:** 4\
**Last updated:** [April 21, 2023, 12:20am UTC](https://discourse.julialang.org/t/macro-for-struct-generation-using-symbolic-parameters/97693 "2023-04-21T00:20:34Z")

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Hello everyone, I try to achieve the following, and can’t find a solution. Maybe its not even possible. I have created a macro, which should help a user to define a certain type of struct. This struct needs a list of p…

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## [Test works in REPL but not as part of @testset](https://discourse.julialang.org/t/test-works-in-repl-but-not-as-part-of-testset/97703)

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**Author:** [@mmv](https://discourse.julialang.org/u/mmv)\
**Replies:** 3\
**Last updated:** [April 20, 2023, 11:54pm UTC](https://discourse.julialang.org/t/test-works-in-repl-but-not-as-part-of-testset/97703 "2023-04-20T23:54:34Z")

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Hi! I started deploying the JMtk15 project on GitHub, but this question is about my local implementation (using Julia 1.8.5 and git 2.39.2 on a recent MacBook Pro): The test function jMtkReadData\_tst\_0100.jl works as ex…

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## [Passing arrays as variable bounds without indexing them is not supported. JuMP](https://discourse.julialang.org/t/passing-arrays-as-variable-bounds-without-indexing-them-is-not-supported-jump/97697)

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**Author:** [@himgoy](https://discourse.julialang.org/u/himgoy)\
**Replies:** 5\
**Last updated:** [April 20, 2023, 11:30pm UTC](https://discourse.julialang.org/t/passing-arrays-as-variable-bounds-without-indexing-them-is-not-supported-jump/97697 "2023-04-20T23:30:19Z")

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Hello Everyone, I am working on a linear programming problem for which I am creating lower bounds and upper bounds for each variable using for loop and pushing it into an array. I have a total of 5489 variables. M = Mo…

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## [How to join multicast group on specific interface](https://discourse.julialang.org/t/how-to-join-multicast-group-on-specific-interface/97724)

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**Author:** [@perfecto25](https://discourse.julialang.org/u/perfecto25)\
**Replies:** 0\
**Last updated:** [April 20, 2023, 10:53pm UTC](https://discourse.julialang.org/t/how-to-join-multicast-group-on-specific-interface/97724 "2023-04-20T22:53:47Z")

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Hello, I need to join a MC group lets say 224.0.0.2 port 21000 and I need to join on a local interface with IP of 192.168.38.10 I want to test to see if Im recieving any data from the group looking at docs, how do I s…

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## [\[ANN\] Announcing ConfigEnv.jl - your secrets manager](https://discourse.julialang.org/t/ann-announcing-configenv-jl-your-secrets-manager/59737)

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**Author:** [@Skoffer](https://discourse.julialang.org/u/Skoffer)\
**Replies:** 2\
**Last updated:** [April 20, 2023, 10:53pm UTC](https://discourse.julialang.org/t/ann-announcing-configenv-jl-your-secrets-manager/59737 "2023-04-20T22:53:43Z")

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I am pleased to announce ConfigEnv.jl, an environment configuration package that loads environment variables from a .env file into ENV . This package was inspired by python-dotenv library and the Twelve-Factor App metho…

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## [Staged Compilation](https://discourse.julialang.org/t/staged-compilation/97682)

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**Author:** [@olynch](https://discourse.julialang.org/u/olynch)\
**Replies:** 8\
**Last updated:** [April 20, 2023, 10:36pm UTC](https://discourse.julialang.org/t/staged-compilation/97682 "2023-04-20T22:36:22Z")

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I’ve been learning more about Racket’s staged compilation system, and I’m wondering if there is any plan in Julia to have more explicit support for the kind of principled stated metaprogramming that goes on in the Racket…

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## [Plot inequality using sympy](https://discourse.julialang.org/t/plot-inequality-using-sympy/97722)

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**Author:** [@jcbritobr](https://discourse.julialang.org/u/jcbritobr)\
**Replies:** 1\
**Last updated:** [April 20, 2023, 9:41pm UTC](https://discourse.julialang.org/t/plot-inequality-using-sympy/97722 "2023-04-20T21:41:53Z")

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How to plot this inequality in sympy? I did other inequations and dont have this problem. Also this works pretty neat in python with plot\_implicit @syms x, y; ineq = Ge(x + 2y, 5); @info ineq; w = solve(…

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## [Blog post: Julia's latency: Past, present and future](https://discourse.julialang.org/t/blog-post-julias-latency-past-present-and-future/96910)

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**Author:** [@jakobnissen](https://discourse.julialang.org/u/jakobnissen)\
**Replies:** 33\
**Last updated:** [April 20, 2023, 9:05pm UTC](https://discourse.julialang.org/t/blog-post-julias-latency-past-present-and-future/96910 "2023-04-20T21:05:51Z")

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Dear all I wrote a new blog post on Julia - this time on the history and future of Julia’s latency. Comments are welcome! https://viralinstruction.com/posts/latency

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## [Error importing xlsx file](https://discourse.julialang.org/t/error-importing-xlsx-file/97719)

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**Author:** [@mgutig](https://discourse.julialang.org/u/mgutig)\
**Replies:** 2\
**Last updated:** [April 20, 2023, 8:24pm UTC](https://discourse.julialang.org/t/error-importing-xlsx-file/97719 "2023-04-20T20:24:30Z")

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Hello, I am new to Julia. My main goal is to do some basic statistical analysis and some plots of tabular data contained in a excel spreadsheet. When I try import the file using XLSX.jl I get an error that I do not under…

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## [Question about coalesced read and write to the global memory using CUDA.jl 2D grid](https://discourse.julialang.org/t/question-about-coalesced-read-and-write-to-the-global-memory-using-cuda-jl-2d-grid/97689)

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**Author:** [@fred\_wu](https://discourse.julialang.org/u/fred_wu)\
**Replies:** 1\
**Last updated:** [April 20, 2023, 8:02pm UTC](https://discourse.julialang.org/t/question-about-coalesced-read-and-write-to-the-global-memory-using-cuda-jl-2d-grid/97689 "2023-04-20T20:02:22Z")

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Hi, I’m having some confusion with a simple test of matrix transpose using a 2D grid in CUDA.jl. I wrote two matrix transpose functions, the only difference is that in the first function, “ix” is along the direction of …

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## [Efficient CuArray shift/rotation](https://discourse.julialang.org/t/efficient-cuarray-shift-rotation/86845)

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**Author:** [@swibe](https://discourse.julialang.org/u/swibe)\
**Replies:** 2\
**Last updated:** [April 20, 2023, 7:55pm UTC](https://discourse.julialang.org/t/efficient-cuarray-shift-rotation/86845 "2023-04-20T19:55:53Z")

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Hi all, I have a workload which regularly needs to perform operations on adjacent elements in an array and accumulate the result. I would sometimes like to be able to run this parallelised across the whole GPU, sometime…

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## [How to plot color in scatter3d based on the value of z direction using backends: plotlyjs](https://discourse.julialang.org/t/how-to-plot-color-in-scatter3d-based-on-the-value-of-z-direction-using-backends-plotlyjs/97712)

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**Author:** [@jianqixi](https://discourse.julialang.org/u/jianqixi)\
**Replies:** 2\
**Last updated:** [April 20, 2023, 7:43pm UTC](https://discourse.julialang.org/t/how-to-plot-color-in-scatter3d-based-on-the-value-of-z-direction-using-backends-plotlyjs/97712 "2023-04-20T19:43:37Z")

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Hi, I am trying to plot the scatter points using scatter3d, I am wondering how to color the points based on the value of z direction. Thanks

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## [Invoking Julia from the Terminal on MacOS](https://discourse.julialang.org/t/invoking-julia-from-the-terminal-on-macos/1124)

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**Author:** [@vincent](https://discourse.julialang.org/u/vincent)\
**Replies:** 11\
**Last updated:** [April 20, 2023, 6:42pm UTC](https://discourse.julialang.org/t/invoking-julia-from-the-terminal-on-macos/1124 "2023-04-20T18:42:57Z")

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hi happy to found julia after long time of hesitations in the choice of a language to make animated graphicals mathematics now, i follow the instructions on http://docs.julialang.org/en/stable/manual/getting-started/ …

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## [Writting long functions with the short function definition syntax. Equivalent? Why not?](https://discourse.julialang.org/t/writting-long-functions-with-the-short-function-definition-syntax-equivalent-why-not/97699)

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**Author:** [@spelufo](https://discourse.julialang.org/u/spelufo)\
**Replies:** 8\
**Last updated:** [April 20, 2023, 5:17pm UTC](https://discourse.julialang.org/t/writting-long-functions-with-the-short-function-definition-syntax-equivalent-why-not/97699 "2023-04-20T17:17:08Z")

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Hi! First, since I’m new let me say I’ve been wanting to use julia for a some time and finally getting into it. Enjoying the language tremendously, thanks for all the great work. There’s a way of writting long functions…

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## [Interpolating multiple parameters into a Cmd](https://discourse.julialang.org/t/interpolating-multiple-parameters-into-a-cmd/97709)

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**Author:** [@bernhard](https://discourse.julialang.org/u/bernhard)\
**Replies:** 2\
**Last updated:** [April 20, 2023, 3:32pm UTC](https://discourse.julialang.org/t/interpolating-multiple-parameters-into-a-cmd/97709 "2023-04-20T15:32:39Z")

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Thank you Steven. Raising this topic from the dead. In my scenario, concatenation of the command fails, as I get single apostrophes in the command that I don’t want, see my first comment. Any ideas how I can avoid thi…

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## [∪ doesn't parse as expected](https://discourse.julialang.org/t/doesnt-parse-as-expected/97671)

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**Author:** [@cstjean](https://discourse.julialang.org/u/cstjean)\
**Replies:** 13\
**Last updated:** [April 20, 2023, 3:26pm UTC](https://discourse.julialang.org/t/doesnt-parse-as-expected/97671 "2023-04-20T15:26:57Z")

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julia\> 1..2 ∪ 3..5 ERROR: syntax: extra token ".." after end of expression Stacktrace: \[1\] top-level scope @ none:1 That’s a bummer. I was hoping to use this syntax inside a macro expansion, but it doesn’t even pars…

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## [Hex2bytes: length of iterable must be even](https://discourse.julialang.org/t/hex2bytes-length-of-iterable-must-be-even/97704)

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**Author:** [@schlichtanders](https://discourse.julialang.org/u/schlichtanders)\
**Replies:** 15\
**Last updated:** [April 20, 2023, 3:14pm UTC](https://discourse.julialang.org/t/hex2bytes-length-of-iterable-must-be-even/97704 "2023-04-20T15:14:14Z")

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Hi there, it seems hex2bytes is really not safe, but depending on the concrete number, it will throw an error. Workaround: using "0" \* string(65537, base=16), but this looks really weird. Can someone explain why such a …

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## [sort(keys(Dict(:a =\> 1, :b =\> 2))) throws MethodError](https://discourse.julialang.org/t/sort-keys-dict-a-1-b-2-throws-methoderror/97701)

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**Author:** [@schlichtanders](https://discourse.julialang.org/u/schlichtanders)\
**Replies:** 13\
**Last updated:** [April 20, 2023, 2:28pm UTC](https://discourse.julialang.org/t/sort-keys-dict-a-1-b-2-throws-methoderror/97701 "2023-04-20T14:28:02Z")

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I guess this is rather a discussion: sort(keys(Dict(:a =\> 1, :b =\> 2))) throws the following MethodError ERROR: MethodError: no method matching sort(::Base.KeySet{Symbol, Dict{Symbol, Int64}}) Closest candidates are: …

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## [How do I dot-assign to a returned value using \`@.\`?](https://discourse.julialang.org/t/how-do-i-dot-assign-to-a-returned-value-using/97683)

<div class="topic-metadata">

**Author:** [@Kino](https://discourse.julialang.org/u/Kino)\
**Replies:** 2\
**Last updated:** [April 20, 2023, 2:34pm UTC](https://discourse.julialang.org/t/how-do-i-dot-assign-to-a-returned-value-using/97683 "2023-04-20T14:34:06Z")

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Let’s create 2 arrays first: julia\> a = rand(100); b = rand(100) Take identity(a) as an example. These works: identity(a) .= b identity(a) .+= b @. $identity(a) += b x = identity(a); @. x = b But this doesn’t: juli…

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## [Problem Saving TIFF Images](https://discourse.julialang.org/t/problem-saving-tiff-images/7267)

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**Author:** [@MLackner](https://discourse.julialang.org/u/MLackner)\
**Replies:** 2\
**Last updated:** [April 20, 2023, 2:30pm UTC](https://discourse.julialang.org/t/problem-saving-tiff-images/7267 "2023-04-20T14:30:21Z")

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Hi! I’ve got trouble saving images in .tiff format. Am I doing something seriously wrong with this code? (I’ve got ImageMagick and QuartzImageIO installed) using Images using TestImages img = testimage("moonsurface.…

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