# Latest

**URL:** https://discourse.julialang.org/latest.md?page=315

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

**Page:** 316

---

## [Why fft with MEASURE plan 10x slower than calling fft directly with CUDA.CUFFT?](https://discourse.julialang.org/t/why-fft-with-measure-plan-10x-slower-than-calling-fft-directly-with-cuda-cufft/119679)

<div class="topic-metadata">

**Author:** [@liuyxpp](https://discourse.julialang.org/u/liuyxpp)\
**Replies:** 7\
**Last updated:** [September 22, 2024, 4:53am UTC](https://discourse.julialang.org/t/why-fft-with-measure-plan-10x-slower-than-calling-fft-directly-with-cuda-cufft/119679 "2024-09-22T04:53:10Z")

</div>

using CUDA using CUDA.CUFFT using BenchmarkTools: @benchmark import FFTW a\_gpu = CUDA.rand(Float32, 128, 128, 128) @benchmark CUDA.@sync fft($a\_gpu) which gives: BenchmarkTools.Trial: 1744 samples with 1 evaluation. …

---

## [Can Julia detect that it is running in headless machine?](https://discourse.julialang.org/t/can-julia-detect-that-it-is-running-in-headless-machine/119696)

<div class="topic-metadata">

**Author:** [@HMegh](https://discourse.julialang.org/u/HMegh)\
**Replies:** 4\
**Last updated:** [September 22, 2024, 4:53pm UTC](https://discourse.julialang.org/t/can-julia-detect-that-it-is-running-in-headless-machine/119696 "2024-09-22T16:53:00Z")

</div>

Hi, I have a small project that I am running on my computer, as well as on a remote server. On my laptop, I typically use Plots.jl or Makie.jl for visualization, but on the server I am typically interested in saving my …

---

## [Can you call a julia function in REPL shell mode?](https://discourse.julialang.org/t/can-you-call-a-julia-function-in-repl-shell-mode/119709)

<div class="topic-metadata">

**Author:** [@devel-chm](https://discourse.julialang.org/u/devel-chm)\
**Replies:** 0\
**Last updated:** [September 22, 2024, 4:31pm UTC](https://discourse.julialang.org/t/can-you-call-a-julia-function-in-repl-shell-mode/119709 "2024-09-22T16:31:00Z")

</div>

Background: I use cygwin on win11 with its /bin in my julia PATH so I can use the cygwin stuff from the REPL shell mode. As I am in a mixed windows (julia and the host OS) and cygwin (the wonderful POSIX world) I’m t…

---

## [Drop in performance after saving data with jldsave](https://discourse.julialang.org/t/drop-in-performance-after-saving-data-with-jldsave/119595)

<div class="topic-metadata">

**Author:** [@J\_B\_R](https://discourse.julialang.org/u/J_B_R)\
**Replies:** 4\
**Last updated:** [September 22, 2024, 3:02pm UTC](https://discourse.julialang.org/t/drop-in-performance-after-saving-data-with-jldsave/119595 "2024-09-22T15:02:02Z")

</div>

Hi I run my Julia code on a cluster and save the output data frequently into a jld2 file by using jldsave. On the desktop computer, performance remains constant, but on the cluster, the performance drops significantly a…

---

## [Requiring a NamedTuple instead of just a tuple to return multiple columns from a function for DataFrames.jl seem unintuitive. Discussion](https://discourse.julialang.org/t/requiring-a-namedtuple-instead-of-just-a-tuple-to-return-multiple-columns-from-a-function-for-dataframes-jl-seem-unintuitive-discussion/119691)

<div class="topic-metadata">

**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 3\
**Last updated:** [September 22, 2024, 1:06pm UTC](https://discourse.julialang.org/t/requiring-a-namedtuple-instead-of-just-a-tuple-to-return-multiple-columns-from-a-function-for-dataframes-jl-seem-unintuitive-discussion/119691 "2024-09-22T13:06:28Z")

</div>

I tried to read the transform doc for DataFrames.jl and I have to say it’s tough going. But I think it contains lots of info. The situation I want to discuss is actually documented in the doc but the question, how do I …

---

## [Failing to import (relatively) large CSV file with Julia and VSC](https://discourse.julialang.org/t/failing-to-import-relatively-large-csv-file-with-julia-and-vsc/112350)

<div class="topic-metadata">

**Author:** [@etiennebert](https://discourse.julialang.org/u/etiennebert)\
**Replies:** 24\
**Last updated:** [September 22, 2024, 12:53pm UTC](https://discourse.julialang.org/t/failing-to-import-relatively-large-csv-file-with-julia-and-vsc/112350 "2024-09-22T12:53:54Z")

</div>

Hello everyone, I am completly new to Julia, so please my apologies if my question is trivial. I have quickly looked for the reply and I have not found it. I need to import a large matrix (40 000 x 40 000, app 6GB) int…

---

## [Confusing Results When Comparing Arrays in Julia](https://discourse.julialang.org/t/confusing-results-when-comparing-arrays-in-julia/119689)

<div class="topic-metadata">

**Author:** [@Kaiyue](https://discourse.julialang.org/u/Kaiyue)\
**Replies:** 5\
**Last updated:** [September 22, 2024, 12:34pm UTC](https://discourse.julialang.org/t/confusing-results-when-comparing-arrays-in-julia/119689 "2024-09-22T12:34:41Z")

</div>

Hi, I’m using Julia version 1.10.5 (2024-08-27) on Ubuntu 22.04. I’ve been experimenting with comparing arrays, but I’m getting some confusing results. Here’s my code: u = \[1;2;3\] v = \[1 2 3\] A = \[1 2 3; 4 5 6\] print(A…

---

## [Converting transformer to predict time series code from Transformers = "~0.1.15" to Transformers = "~0.2.8"](https://discourse.julialang.org/t/converting-transformer-to-predict-time-series-code-from-transformers-0-1-15-to-transformers-0-2-8/119695)

<div class="topic-metadata">

**Author:** [@kondjenim](https://discourse.julialang.org/u/kondjenim)\
**Replies:** 0\
**Last updated:** [September 22, 2024, 11:33am UTC](https://discourse.julialang.org/t/converting-transformer-to-predict-time-series-code-from-transformers-0-1-15-to-transformers-0-2-8/119695 "2024-09-22T11:33:46Z")

</div>

Hi all, Anyone to help me in converting the Use transformer to predict time series code GitHub - iwasnothing/julia\_transformer\_ts: Time series prediction using transformer in Julia from Transformers = “~0.1.15” to Trans…

---

## [Changing the basic type of a Unitful quantity](https://discourse.julialang.org/t/changing-the-basic-type-of-a-unitful-quantity/119665)

<div class="topic-metadata">

**Author:** [@Maurizio\_Tomasi](https://discourse.julialang.org/u/Maurizio_Tomasi)\
**Replies:** 2\
**Last updated:** [September 22, 2024, 10:26am UTC](https://discourse.julialang.org/t/changing-the-basic-type-of-a-unitful-quantity/119665 "2024-09-22T10:26:34Z")

</div>

I’m developing some electromagnetic code and want to use Unitful.jl thoroughly to make sure that data structures and algorithms are physically consistent. One feature I would like to have is the ability to quickly set u…

---

## [Accessing the macOS Keychain from Julia](https://discourse.julialang.org/t/accessing-the-macos-keychain-from-julia/119693)

<div class="topic-metadata">

**Author:** [@e3c6](https://discourse.julialang.org/u/e3c6)\
**Replies:** 1\
**Last updated:** [September 22, 2024, 10:21am UTC](https://discourse.julialang.org/t/accessing-the-macos-keychain-from-julia/119693 "2024-09-22T10:21:08Z")

</div>

How can one access the macOS Keychain from Julia ? To store or retrieve passwords.

---

## [Coding different iterations over a dataset](https://discourse.julialang.org/t/coding-different-iterations-over-a-dataset/119675)

<div class="topic-metadata">

**Author:** [@gideonsimpson](https://discourse.julialang.org/u/gideonsimpson)\
**Replies:** 3\
**Last updated:** [September 22, 2024, 6:26am UTC](https://discourse.julialang.org/t/coding-different-iterations-over-a-dataset/119675 "2024-09-22T06:26:32Z")

</div>

I have some code currently implemented via multiple dispatch that looks vaguely like: function process\_data(data,n) for i in 1:n # apply operation to entire data set, data end end function process\_data(data\_se…

---

## [MLJ for XGBoost - extracting feature gain](https://discourse.julialang.org/t/mlj-for-xgboost-extracting-feature-gain/93518)

<div class="topic-metadata">

**Author:** [@Ivan](https://discourse.julialang.org/u/Ivan)\
**Replies:** 4\
**Last updated:** [September 22, 2024, 5:13am UTC](https://discourse.julialang.org/t/mlj-for-xgboost-extracting-feature-gain/93518 "2024-09-22T05:13:23Z")

</div>

I have used MLJ for XGBoost in the past, and was able to explore the feature importances doing the following: using MLJ, DataFrames @load XGBoostRegressor pkg=XGBoost X = DataFrame(rand((0, 1), (200, 5)), :auto) y = ran…

---

## [How to show all xlabels in violin plot](https://discourse.julialang.org/t/how-to-show-all-xlabels-in-violin-plot/119627)

<div class="topic-metadata">

**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 5\
**Last updated:** [September 21, 2024, 8:11pm UTC](https://discourse.julialang.org/t/how-to-show-all-xlabels-in-violin-plot/119627 "2024-09-21T20:11:29Z")

</div>

Hi, In the code below, only evenly indexed labels display. How do I show all xlabels? Thanks! using StatsPlots x = randn(1000, 16) labels = map(x -\> randstring(3), 1:16) violin(permutedims(labels), x, rotation = 90, …

---

## [Help with gradient-based optimizers](https://discourse.julialang.org/t/help-with-gradient-based-optimizers/119376)

<div class="topic-metadata">

**Author:** [@jwalker](https://discourse.julialang.org/u/jwalker)\
**Replies:** 14\
**Last updated:** [September 21, 2024, 8:03pm UTC](https://discourse.julialang.org/t/help-with-gradient-based-optimizers/119376 "2024-09-21T20:03:11Z")

</div>

I’m using Optimization.jl and Optim.jl to solve an optimization problem for which I have gradient information (via AD). What I’ve found is that the methods that use the gradient information perform worse than the derivat…

---

## [Cholesky decomposition of low-rank positive-semidefinite matrix](https://discourse.julialang.org/t/cholesky-decomposition-of-low-rank-positive-semidefinite-matrix/70397)

<div class="topic-metadata">

**Author:** [@Shuvomoy\_Das\_Gupta](https://discourse.julialang.org/u/Shuvomoy_Das_Gupta)\
**Replies:** 3\
**Last updated:** [October 26, 2021, 12:54pm UTC](https://discourse.julialang.org/t/cholesky-decomposition-of-low-rank-positive-semidefinite-matrix/70397 "2021-10-26T12:54:43Z")

</div>

Dear All, I have a rank r positive-semidefinite matrix M, which I am trying to decompose via lower-triangularlar Cholesky factorization M=LL^\\top, but I am particularly interested in computing an L that has r positive d…

---

## [Lux.jl vs Jax](https://discourse.julialang.org/t/lux-jl-vs-jax/119654)

<div class="topic-metadata">

**Author:** [@ijk](https://discourse.julialang.org/u/ijk)\
**Replies:** 6\
**Last updated:** [September 21, 2024, 6:12pm UTC](https://discourse.julialang.org/t/lux-jl-vs-jax/119654 "2024-09-21T18:12:02Z")

</div>

I’ve started using Julia this semester, and would like to reimplement some ML models from Jax to Lux.jl. I have three concerns: I noticed there aren’t constructs like vmap. My existing Jax code has quite a few vmap cal…

---

## [JUHPC: HPC setup for Juliaup, Julia and some HPC key packages](https://discourse.julialang.org/t/juhpc-hpc-setup-for-juliaup-julia-and-some-hpc-key-packages/119556)

<div class="topic-metadata">

**Author:** [@samo](https://discourse.julialang.org/u/samo)\
**Replies:** 0\
**Last updated:** [September 18, 2024, 3:06pm UTC](https://discourse.julialang.org/t/juhpc-hpc-setup-for-juliaup-julia-and-some-hpc-key-packages/119556 "2024-09-18T15:06:19Z")

</div>

@channel Dear Julia HPC community! After an odyssey through stacked environments with pre-installed packages and other unsatisfying solutions, the Julia HPC community is now able to do a good Julia HPC setup. Yet, the …

---

## [Set defaults for a part of Symbolics.Arr](https://discourse.julialang.org/t/set-defaults-for-a-part-of-symbolics-arr/119678)

<div class="topic-metadata">

**Author:** [@Bart\_van\_de\_Lint](https://discourse.julialang.org/u/Bart_van_de_Lint)\
**Replies:** 1\
**Last updated:** [September 21, 2024, 3:51pm UTC](https://discourse.julialang.org/t/set-defaults-for-a-part-of-symbolics-arr/119678 "2024-09-21T15:51:30Z")

</div>

Is it possible to set defaults for only a part of a Symbolics.Arr when defining a model? So can I for example only set defaults for pos\[:, 4:8\], while not setting defaults for pos\[:, 1:3\] and pos\[:, 9:10\]? @variables …

---

## [\[ANN\] TypedMatrices.jl – An Extensible Julia Matrix Collection Utilizing Type System](https://discourse.julialang.org/t/ann-typedmatrices-jl-an-extensible-julia-matrix-collection-utilizing-type-system/119668)

<div class="topic-metadata">

**Author:** [@Andy\_Zhang](https://discourse.julialang.org/u/Andy_Zhang)\
**Replies:** 0\
**Last updated:** [September 21, 2024, 9:31am UTC](https://discourse.julialang.org/t/ann-typedmatrices-jl-an-extensible-julia-matrix-collection-utilizing-type-system/119668 "2024-09-21T09:31:02Z")

</div>

Hi everyone, I’m excited to announce the release of TypedMatrices.jl, a new package designed to extend the Julia matrix ecosystem with a focus on performance and flexibility, leveraging Julia’s powerful type system. Ov…

---

## [String optimisation in Julia](https://discourse.julialang.org/t/string-optimisation-in-julia/119301)

<div class="topic-metadata">

**Author:** [@sivakon](https://discourse.julialang.org/u/sivakon)\
**Replies:** 21\
**Last updated:** [September 21, 2024, 2:42pm UTC](https://discourse.julialang.org/t/string-optimisation-in-julia/119301 "2024-09-21T14:42:29Z")

</div>

Came across this benchmark that tries to create large string and save to file. The difference between Julia and Java is very high. (I’m assuming Java version the string is being saved and reused without allocating?). …

---

## [ModelingToolkit 9.39 is broken, 9.40.1 works well](https://discourse.julialang.org/t/modelingtoolkit-9-39-is-broken-9-40-1-works-well/119670)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 7\
**Last updated:** [September 21, 2024, 2:40pm UTC](https://discourse.julialang.org/t/modelingtoolkit-9-39-is-broken-9-40-1-works-well/119670 "2024-09-21T14:40:03Z")

</div>

Steps to reproduce: git clone https://github.com/ufechner7/Tethers.jl/ cd Tethers.jl git checkout broken julia --project and then in Julia using Pkg Pkg.update() include("src/Tether\_01.jl") This gives the following …

---

## [Embedded julia in multithread c++: examples and doc](https://discourse.julialang.org/t/embedded-julia-in-multithread-c-examples-and-doc/119011)

<div class="topic-metadata">

**Author:** [@Sergey](https://discourse.julialang.org/u/Sergey)\
**Replies:** 4\
**Last updated:** [September 21, 2024, 2:18pm UTC](https://discourse.julialang.org/t/embedded-julia-in-multithread-c-examples-and-doc/119011 "2024-09-21T14:18:44Z")

</div>

Hi! Im searching for a scripting language which scripts could be run in different threads. No data share, only separate tasks. (with different math modules) Julia seems to be able to work this way, but i found non of …

---

## [Spark.jl and Kafka](https://discourse.julialang.org/t/spark-jl-and-kafka/119677)

<div class="topic-metadata">

**Author:** [@Jose\_Ghislain\_Quenum](https://discourse.julialang.org/u/Jose_Ghislain_Quenum)\
**Replies:** 0\
**Last updated:** [September 21, 2024, 2:08pm UTC](https://discourse.julialang.org/t/spark-jl-and-kafka/119677 "2024-09-21T14:08:59Z")

</div>

How can I get spark.jl to read a stream from Kafka?

---

## [Julia user meetup in Trondheim?](https://discourse.julialang.org/t/julia-user-meetup-in-trondheim/99391)

<div class="topic-metadata">

**Author:** [@kellertuer](https://discourse.julialang.org/u/kellertuer)\
**Replies:** 29\
**Last updated:** [September 21, 2024, 1:34pm UTC](https://discourse.julialang.org/t/julia-user-meetup-in-trondheim/99391 "2024-09-21T13:34:25Z")

</div>

:wave: from Gløshaugen. If there are enough Julia users in Trondheim we should maybe start a small meet-up.

---

## [Connect REPL to jupyter notebook kernel](https://discourse.julialang.org/t/connect-repl-to-jupyter-notebook-kernel/86632)

<div class="topic-metadata">

**Author:** [@daharn](https://discourse.julialang.org/u/daharn)\
**Replies:** 7\
**Last updated:** [September 21, 2024, 10:43am UTC](https://discourse.julialang.org/t/connect-repl-to-jupyter-notebook-kernel/86632 "2024-09-21T10:43:53Z")

</div>

I am using the jupyter notebook Julia extension for VS Code and find it quite nice. However, when debugging my commands I often find myself reproducing my notebook steps in a script and then run them in a REPL to be able…

---

## [(Statistical) Modeling of climate hazards - tropical cyclone](https://discourse.julialang.org/t/statistical-modeling-of-climate-hazards-tropical-cyclone/119648)

<div class="topic-metadata">

**Author:** [@aramirezreyes](https://discourse.julialang.org/u/aramirezreyes)\
**Replies:** 5\
**Last updated:** [September 21, 2024, 10:40am UTC](https://discourse.julialang.org/t/statistical-modeling-of-climate-hazards-tropical-cyclone/119648 "2024-09-21T10:40:09Z")

</div>

Hi! My team at Moody’s (London Office :uk: ) is hiring a tropical cyclone modeler :cyclone:. The job description mentions :julia: but I must warn that our main workhorse is the R language. I personally use julia in my ex…

---

## [MTK - struggling with initialization](https://discourse.julialang.org/t/mtk-struggling-with-initialization/119643)

<div class="topic-metadata">

**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 5\
**Last updated:** [September 21, 2024, 10:38am UTC](https://discourse.julialang.org/t/mtk-struggling-with-initialization/119643 "2024-09-21T10:38:11Z")

</div>

I’m converting a model from Modelica to ModelingToolkit \[MTK\]. The Modelica-version works fine using OpenModelica, but the ModelingToolkit has problems wrt. initialization. Here is the Julia+MTK code that is equivalent …

---

## [Why does the speed of Julia in AOT compilation differ from UX4?](https://discourse.julialang.org/t/why-does-the-speed-of-julia-in-aot-compilation-differ-from-ux4/119657)

<div class="topic-metadata">

**Author:** [@aaoo](https://discourse.julialang.org/u/aaoo)\
**Replies:** 12\
**Last updated:** [September 21, 2024, 3:14am UTC](https://discourse.julialang.org/t/why-does-the-speed-of-julia-in-aot-compilation-differ-from-ux4/119657 "2024-09-21T03:14:26Z")

</div>

As the following picture shows, there are two different Julia versions in the speed comparison. The AOT compiled version reaches speeds as fast as Fortran, etc. However, the other version is slower and closer to Python. …

---

## [Logical "and", &&, and mapreduce](https://discourse.julialang.org/t/logical-and-and-mapreduce/119659)

<div class="topic-metadata">

**Author:** [@jlapeyre](https://discourse.julialang.org/u/jlapeyre)\
**Replies:** 8\
**Last updated:** [September 21, 2024, 8:23am UTC](https://discourse.julialang.org/t/logical-and-and-mapreduce/119659 "2024-09-21T08:23:07Z")

</div>

I wonder if a function like and(x::Bool, y::Bool) = x && y would be useful. You can currently do mapreduce(f, &, x, y), where f takes two arguments and returns Bool. But and always returns Bool (only has this one meth…

---

## [\`@profview\` blank in VSCode when profiling Flux](https://discourse.julialang.org/t/profview-blank-in-vscode-when-profiling-flux/119602)

<div class="topic-metadata">

**Author:** [@BioTurboNick](https://discourse.julialang.org/u/BioTurboNick)\
**Replies:** 4\
**Last updated:** [September 21, 2024, 6:51am UTC](https://discourse.julialang.org/t/profview-blank-in-vscode-when-profiling-flux/119602 "2024-09-21T06:51:30Z")

</div>

I’ve been experiencing a blank window when using @profview while profiling a Flux model. The editor shows the blue/red bars for time spent in each line properly. But I can’t even save the profile to HTML - I select a sa…

[Previous page](https://discourse.julialang.org/latest.md?page=314)

[Next page](https://discourse.julialang.org/latest.md?page=316)