# Latest

**URL:** https://discourse.julialang.org/latest.md?page=544

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

**Page:** 545

---

## [Scope Issues of Exported Functions in Module](https://discourse.julialang.org/t/scope-issues-of-exported-functions-in-module/106784)

<div class="topic-metadata">

**Author:** [@Ian\_Harreschou](https://discourse.julialang.org/u/Ian_Harreschou)\
**Replies:** 9\
**Last updated:** [November 28, 2023, 12:44am UTC](https://discourse.julialang.org/t/scope-issues-of-exported-functions-in-module/106784 "2023-11-28T00:44:01Z")

</div>

Probably a basic question and answer I am searching for here, but I am trying to get into package development and it has been quite difficult. This time around, I have made much more progress, but just ran into issues wi…

---

## [Prime number hunting](https://discourse.julialang.org/t/prime-number-hunting/106771)

<div class="topic-metadata">

**Author:** [@Loves\_Reddit](https://discourse.julialang.org/u/Loves_Reddit)\
**Replies:** 2\
**Last updated:** [November 27, 2023, 10:16pm UTC](https://discourse.julialang.org/t/prime-number-hunting/106771 "2023-11-27T22:16:38Z")

</div>

Hello are there any Julia programs for prime number hunting similar to GIMPS?

---

## [How to document functions twice?](https://discourse.julialang.org/t/how-to-document-functions-twice/106816)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 4\
**Last updated:** [November 27, 2023, 9:45pm UTC](https://discourse.julialang.org/t/how-to-document-functions-twice/106816 "2023-11-27T21:45:08Z")

</div>

I want to refer to a function twice in my documentation, once I document the functions per file, and once per category. How can I achieve that? If I refer to a function in two files like this: \`\`\`@docs plot\_cp plot\_fou…

---

## [What is a safer way to expand other packages' function?](https://discourse.julialang.org/t/what-is-a-safer-way-to-expand-other-packages-function/106818)

<div class="topic-metadata">

**Author:** [@tiZ](https://discourse.julialang.org/u/tiZ)\
**Replies:** 8\
**Last updated:** [November 27, 2023, 9:21pm UTC](https://discourse.julialang.org/t/what-is-a-safer-way-to-expand-other-packages-function/106818 "2023-11-27T21:21:23Z")

</div>

Hi friends, I am try to expand the DataFrame function for my data struct, I defined it as: using DataFrames DataFrame(Q::mystrust) = begin # do something end it works well, but when I write above as a file and incl…

---

## [Is Julia’s destiny in the creative industry and building the virtual world?](https://discourse.julialang.org/t/is-julia-s-destiny-in-the-creative-industry-and-building-the-virtual-world/106675)

<div class="topic-metadata">

**Author:** [@Tarny\_GG\_Channie](https://discourse.julialang.org/u/Tarny_GG_Channie)\
**Replies:** 22\
**Last updated:** [November 27, 2023, 9:18pm UTC](https://discourse.julialang.org/t/is-julia-s-destiny-in-the-creative-industry-and-building-the-virtual-world/106675 "2023-11-27T21:18:29Z")

</div>

Python found its destiny in machine learning. R found its destiny with statistics. JavaScript found its destiny being the web language. Is Julia’s destiny building the virtual world? Why? Because the virtual world offe…

---

## [Can I create a reference to a section of a matrix without copying its elements?](https://discourse.julialang.org/t/can-i-create-a-reference-to-a-section-of-a-matrix-without-copying-its-elements/106813)

<div class="topic-metadata">

**Author:** [@Bottom](https://discourse.julialang.org/u/Bottom)\
**Replies:** 3\
**Last updated:** [November 27, 2023, 8:01pm UTC](https://discourse.julialang.org/t/can-i-create-a-reference-to-a-section-of-a-matrix-without-copying-its-elements/106813 "2023-11-27T20:01:24Z")

</div>

In my code I have some 3D matrices M\[m,i,j\] where I iterate much less frequent over the first index (m: timestep) than over the other two (i,j: spatial discretization). I would like to have an alias for M\[m, :, :\] so I c…

---

## [Failure to precompile Plots.jl in Linux](https://discourse.julialang.org/t/failure-to-precompile-plots-jl-in-linux/106608)

<div class="topic-metadata">

**Author:** [@Fengyu](https://discourse.julialang.org/u/Fengyu)\
**Replies:** 4\
**Last updated:** [November 27, 2023, 7:31pm UTC](https://discourse.julialang.org/t/failure-to-precompile-plots-jl-in-linux/106608 "2023-11-27T19:31:43Z")

</div>

Hi, I have trouble to precompile Plots.jl in Linux. I looked through a couple of similar questions but my problem still can not be solved. Any help will be appreciated. Below is the error msg and environment info: julia\>…

---

## [Setting the number of cores for a Gurobi license in JuMPg](https://discourse.julialang.org/t/setting-the-number-of-cores-for-a-gurobi-license-in-jumpg/106809)

<div class="topic-metadata">

**Author:** [@hdavid16](https://discourse.julialang.org/u/hdavid16)\
**Replies:** 3\
**Last updated:** [November 27, 2023, 5:46pm UTC](https://discourse.julialang.org/t/setting-the-number-of-cores-for-a-gurobi-license-in-jumpg/106809 "2023-11-27T17:46:33Z")

</div>

Any help with the following error would be much appreciated. I tried set\_optimizer\_attribute(model,"Threads",8), but still get the error… julia\> set\_optimizer(model,Gurobi.Optimizer) ERROR: Gurobi Error 10009: License i…

---

## [What does prevent a package (here Makie) to upgrade?](https://discourse.julialang.org/t/what-does-prevent-a-package-here-makie-to-upgrade/106805)

<div class="topic-metadata">

**Author:** [@davide](https://discourse.julialang.org/u/davide)\
**Replies:** 3\
**Last updated:** [November 27, 2023, 5:43pm UTC](https://discourse.julialang.org/t/what-does-prevent-a-package-here-makie-to-upgrade/106805 "2023-11-27T17:43:29Z")

</div>

I cannot figure it out from the output of status --outdated and status --outdated -m and I don’t know what I am missing. Julia v. 1.9.4 on a Linux machine. Specifically, for Makie / GLMakie / CairoMakie and AlgebraOfGr…

---

## [Makie text function no longer working](https://discourse.julialang.org/t/makie-text-function-no-longer-working/106812)

<div class="topic-metadata">

**Author:** [@p\_f](https://discourse.julialang.org/u/p_f)\
**Replies:** 2\
**Last updated:** [November 27, 2023, 5:29pm UTC](https://discourse.julialang.org/t/makie-text-function-no-longer-working/106812 "2023-11-27T17:29:26Z")

</div>

The text function from Makie is no longer working in an environment. I have updated GLMakie v0.9.1 and CairoMakie v0.11.1. It does work in my global environment using GLMakie v0.8.6 In the local environment where it do…

---

## [Using sparse matrix in CUDA kernel](https://discourse.julialang.org/t/using-sparse-matrix-in-cuda-kernel/106704)

<div class="topic-metadata">

**Author:** [@joel](https://discourse.julialang.org/u/joel)\
**Replies:** 1\
**Last updated:** [November 27, 2023, 5:05pm UTC](https://discourse.julialang.org/t/using-sparse-matrix-in-cuda-kernel/106704 "2023-11-27T17:05:24Z")

</div>

Hi, I’m trying to call nonzeros on a sparse matrix in my CUDA kernel but I’m getting a dynamic function invocation error: unsupported dynamic function invocation (call to nonzeros). Is this simply not supported or am I…

---

## [Error when implementing multidimensional kernel](https://discourse.julialang.org/t/error-when-implementing-multidimensional-kernel/106738)

<div class="topic-metadata">

**Author:** [@albertomercurio](https://discourse.julialang.org/u/albertomercurio)\
**Replies:** 6\
**Last updated:** [November 27, 2023, 5:01pm UTC](https://discourse.julialang.org/t/error-when-implementing-multidimensional-kernel/106738 "2023-11-27T17:01:07Z")

</div>

Hello, I was implementing a very simple example of kernel programming with CUDA.jl. As an example, I took the addition of two matrices. The used code is the following: function \_add\_kernel!(C, A, B, m, n) index\_i =…

---

## [Typeof on Any vs Typeof on Union?](https://discourse.julialang.org/t/typeof-on-any-vs-typeof-on-union/106806)

<div class="topic-metadata">

**Author:** [@hlbnet](https://discourse.julialang.org/u/hlbnet)\
**Replies:** 3\
**Last updated:** [November 27, 2023, 4:48pm UTC](https://discourse.julialang.org/t/typeof-on-any-vs-typeof-on-union/106806 "2023-11-27T16:48:10Z")

</div>

Hi everybody, Is there a general explanation of why typeof comparisons on Any is 20 times slower than on Union in the following example ? Especially, the huge memory allocation in one case but not in the other ? Here …

---

## [Speed of multiple dispatch](https://discourse.julialang.org/t/speed-of-multiple-dispatch/106717)

<div class="topic-metadata">

**Author:** [@hlbnet](https://discourse.julialang.org/u/hlbnet)\
**Replies:** 14\
**Last updated:** [November 27, 2023, 4:25pm UTC](https://discourse.julialang.org/t/speed-of-multiple-dispatch/106717 "2023-11-27T16:25:24Z")

</div>

Hello, In the following example, multiple dispatch is more that 10 times slower than typeof comparisons. Is it expected, or is there some issue in my code ? Ouput: Size=20000 If typeof 1006900000 1.576137 seconds…

---

## [Should Julia have a recognized set of language specific metasyntactic variables?](https://discourse.julialang.org/t/should-julia-have-a-recognized-set-of-language-specific-metasyntactic-variables/106474)

<div class="topic-metadata">

**Author:** [@jmanthony3](https://discourse.julialang.org/u/jmanthony3)\
**Replies:** 11\
**Last updated:** [November 27, 2023, 4:21pm UTC](https://discourse.julialang.org/t/should-julia-have-a-recognized-set-of-language-specific-metasyntactic-variables/106474 "2023-11-27T16:21:10Z")

</div>

Would it be appropriate for the Julia community to have a list of commonly used metasyntactic variables like other languages? For example, Python has spam, ham and eggs. I imagine that such a list could increase the leg…

---

## [What is the the Julian way to find out how to subset an arbitrary object?](https://discourse.julialang.org/t/what-is-the-the-julian-way-to-find-out-how-to-subset-an-arbitrary-object/106807)

<div class="topic-metadata">

**Author:** [@Tetrakai](https://discourse.julialang.org/u/Tetrakai)\
**Replies:** 4\
**Last updated:** [November 27, 2023, 4:18pm UTC](https://discourse.julialang.org/t/what-is-the-the-julian-way-to-find-out-how-to-subset-an-arbitrary-object/106807 "2023-11-27T16:18:12Z")

</div>

This is basically a followup to my earlier question, since perhaps the title ended up being misleading: The FastAI package has objects called “Learner”. Is there some standard way to investigate what is in these beside…

---

## [Is there a possibility to prevent task switches in a block of code?](https://discourse.julialang.org/t/is-there-a-possibility-to-prevent-task-switches-in-a-block-of-code/106798)

<div class="topic-metadata">

**Author:** [@schlichtanders](https://discourse.julialang.org/u/schlichtanders)\
**Replies:** 49\
**Last updated:** [November 27, 2023, 3:54pm UTC](https://discourse.julialang.org/t/is-there-a-possibility-to-prevent-task-switches-in-a-block-of-code/106798 "2023-11-27T15:54:16Z")

</div>

I would like to ensure that within a certain block of code no task switch can happen. A bit like an “atomic block” for async tasks

---

## [How to update Makie plot upon zooming?](https://discourse.julialang.org/t/how-to-update-makie-plot-upon-zooming/106788)

<div class="topic-metadata">

**Author:** [@Zetison](https://discourse.julialang.org/u/Zetison)\
**Replies:** 2\
**Last updated:** [November 27, 2023, 3:21pm UTC](https://discourse.julialang.org/t/how-to-update-makie-plot-upon-zooming/106788 "2023-11-27T15:21:40Z")

</div>

I’m trying to update the plot with higher resolution when zooming in a Makie plot. But it seems events(ax).scroll is not triggered. Is this a bug? The following MWE illustrates this issue: using GLMakie function updat…

---

## [\[ANN\] SkeelBerzins.jl v1.0.0 - A universal solver for 1D elliptic and parabolic PDEs](https://discourse.julialang.org/t/ann-skeelberzins-jl-v1-0-0-a-universal-solver-for-1d-elliptic-and-parabolic-pdes/106804)

<div class="topic-metadata">

**Author:** [@g\_pourtier](https://discourse.julialang.org/u/g_pourtier)\
**Replies:** 0\
**Last updated:** [November 27, 2023, 3:16pm UTC](https://discourse.julialang.org/t/ann-skeelberzins-jl-v1-0-0-a-universal-solver-for-1d-elliptic-and-parabolic-pdes/106804 "2023-11-27T15:16:17Z")

</div>

I am pleased to announce the official release of SkeelBerzins.jl v1.0.0. SkeelBerzins.jl is a universal solver for systems of one-dimensional elliptic and parabolic nonlinear partial differential equations. The package …

---

## [Discourse not showing preview for Julia docs](https://discourse.julialang.org/t/discourse-not-showing-preview-for-julia-docs/106803)

<div class="topic-metadata">

**Author:** [@jling](https://discourse.julialang.org/u/jling)\
**Replies:** 1\
**Last updated:** [November 27, 2023, 2:38pm UTC](https://discourse.julialang.org/t/discourse-not-showing-preview-for-julia-docs/106803 "2023-11-27T14:38:44Z")

</div>

https://docs.julialang.org/en/v1/base/io-network/#Base.readuntil

---

## [Huge computation error in Float32?](https://discourse.julialang.org/t/huge-computation-error-in-float32/106746)

<div class="topic-metadata">

**Author:** [@tomtom](https://discourse.julialang.org/u/tomtom)\
**Replies:** 12\
**Last updated:** [November 27, 2023, 2:37pm UTC](https://discourse.julialang.org/t/huge-computation-error-in-float32/106746 "2023-11-27T14:37:39Z")

</div>

the following shows that s1 was hugely mis-computed. It happens when doing calculations in Float32. Everything is fine in Float64. Random.seed!(1); n = 1000000; a = rand(Float32, n); b = rand(Float32, 100, n); s1 = 0f0;…

---

## [Is it possible to cut a vector into 2 pieces without allocations?](https://discourse.julialang.org/t/is-it-possible-to-cut-a-vector-into-2-pieces-without-allocations/106749)

<div class="topic-metadata">

**Author:** [@Leo\_I](https://discourse.julialang.org/u/Leo_I)\
**Replies:** 11\
**Last updated:** [November 27, 2023, 10:25am UTC](https://discourse.julialang.org/t/is-it-possible-to-cut-a-vector-into-2-pieces-without-allocations/106749 "2023-11-27T10:25:36Z")

</div>

Let’s say I have toy data m, n = 10^3, 10^6; x1 = \[rand(-1:0.001:1,s) for j=1:n for s in rand(1:m,1)\] len = \[rand(1:length(x)) for x in x1\] I wish to split each vector x1\[j\] into x1\[j\]\[1:len\[j\]\] and x1\[j\]\[len\[j\]:end…

---

## [Definition of struct written from C and read-only in Julia](https://discourse.julialang.org/t/definition-of-struct-written-from-c-and-read-only-in-julia/106667)

<div class="topic-metadata">

**Author:** [@PatrickHaecker](https://discourse.julialang.org/u/PatrickHaecker)\
**Replies:** 7\
**Last updated:** [November 27, 2023, 10:57am UTC](https://discourse.julialang.org/t/definition-of-struct-written-from-c-and-read-only-in-julia/106667 "2023-11-27T10:57:45Z")

</div>

I hand over a struct to a C library which periodically will enter values in the struct’s field and then call a Julia callback function. The struct is defined and gets created (memory allocated) in Julia, but only C write…

---

## [When I add any package, PrettyTables will get stuck here and cannot be executed. I need to control+C to close it](https://discourse.julialang.org/t/when-i-add-any-package-prettytables-will-get-stuck-here-and-cannot-be-executed-i-need-to-control-c-to-close-it/106301)

<div class="topic-metadata">

**Author:** [@wang\_ruoxu](https://discourse.julialang.org/u/wang_ruoxu)\
**Replies:** 3\
**Last updated:** [November 27, 2023, 10:24am UTC](https://discourse.julialang.org/t/when-i-add-any-package-prettytables-will-get-stuck-here-and-cannot-be-executed-i-need-to-control-c-to-close-it/106301 "2023-11-27T10:24:14Z")

</div>

what can i do to solved it . Julia Version 1.9.4 Commit 8e5136fa297 (2023-11-14 08:46 UTC) Build Info: Official https://julialang.org/ release Platform Info: OS: Linux (x86\_64-linux-gnu) CPU: 16 × Intel(R) Core™ i…

---

## [How to suppress Pkg messages?](https://discourse.julialang.org/t/how-to-suppress-pkg-messages/106776)

<div class="topic-metadata">

**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 5\
**Last updated:** [November 27, 2023, 10:07am UTC](https://discourse.julialang.org/t/how-to-suppress-pkg-messages/106776 "2023-11-27T10:07:33Z")

</div>

pkrysl@BlackCube MINGW64 /d/BoneShaker.jl (main) $ julia --quiet …

---

## [Parametric types & multiple dispatch](https://discourse.julialang.org/t/parametric-types-multiple-dispatch/106650)

<div class="topic-metadata">

**Author:** [@Lincoln\_Hannah](https://discourse.julialang.org/u/Lincoln_Hannah)\
**Replies:** 7\
**Last updated:** [November 27, 2023, 9:30am UTC](https://discourse.julialang.org/t/parametric-types-multiple-dispatch/106650 "2023-11-27T09:30:34Z")

</div>

Method choice can be determined by a parametric type struct X{x} end f(::X{:x1}) = 1 f(::X{:x2}) = 2 f(X{:x1}()) # 1 f(X{:x2}()) # 2 Why not allow it to be determined just with the parameter ? f({:x1}) = 1 f({:x2}) …

---

## [Using @eval with zipped pair of Symbols](https://discourse.julialang.org/t/using-eval-with-zipped-pair-of-symbols/106787)

<div class="topic-metadata">

**Author:** [@Daptine](https://discourse.julialang.org/u/Daptine)\
**Replies:** 3\
**Last updated:** [November 27, 2023, 7:33am UTC](https://discourse.julialang.org/t/using-eval-with-zipped-pair-of-symbols/106787 "2023-11-27T07:33:22Z")

</div>

f1(x) = x+1 f2(x) = x+2 for (t, op) in zip((:Int, :Float64),(:f1, :f2)) print(t, " ", op, "\\n") @eval begin f3($op) = begin println($t) println($op) x -\> $t($op(x) + 3) end end end f3…

---

## [Int and float functions](https://discourse.julialang.org/t/int-and-float-functions/106770)

<div class="topic-metadata">

**Author:** [@fdekerme](https://discourse.julialang.org/u/fdekerme)\
**Replies:** 7\
**Last updated:** [November 27, 2023, 6:43am UTC](https://discourse.julialang.org/t/int-and-float-functions/106770 "2023-11-27T06:43:55Z")

</div>

Hello, Just a question: Why is the Int function capitalized and the float function lower-case? julia\> 0x0001 |\> Int 1 julia\> 0x0001 |\> float 1.0 julia\> 0x0001 |\> Float ERROR: UndefVarError: \`Float\` not defined Stackt…

---

## [\[ANN\] ReactiveToolkit.jl: Build reactive, "soft" real-time systems in Julia for hardware-in-the-loop controls](https://discourse.julialang.org/t/ann-reactivetoolkit-jl-build-reactive-soft-real-time-systems-in-julia-for-hardware-in-the-loop-controls/106781)

<div class="topic-metadata">

**Author:** [@narijauskas](https://discourse.julialang.org/u/narijauskas)\
**Replies:** 0\
**Last updated:** [November 27, 2023, 5:46am UTC](https://discourse.julialang.org/t/ann-reactivetoolkit-jl-build-reactive-soft-real-time-systems-in-julia-for-hardware-in-the-loop-controls/106781 "2023-11-27T05:46:42Z")

</div>

I’m excited to announce a new package providing some tools to enable asynchronous, concurrent, reactive, “soft real-time” programming in Julia. The target audience of this package consists of roboticists working at the i…

---

## [Looking for assistance with maintaining NormalForms.jl](https://discourse.julialang.org/t/looking-for-assistance-with-maintaining-normalforms-jl/105963)

<div class="topic-metadata">

**Author:** [@brainandforce](https://discourse.julialang.org/u/brainandforce)\
**Replies:** 2\
**Last updated:** [November 27, 2023, 1:17am UTC](https://discourse.julialang.org/t/looking-for-assistance-with-maintaining-normalforms-jl/105963 "2023-11-27T01:17:13Z")

</div>

NormalForms.jl is a package which provides the Smith and Hermite normal forms, integer matrix decompositions that are useful in my domain (chemistry - I developed it as a dependency of Electrum.jl because the Smith norma…

[Previous page](https://discourse.julialang.org/latest.md?page=543)

[Next page](https://discourse.julialang.org/latest.md?page=545)