# Latest

**URL:** https://discourse.julialang.org/latest.md?page=674

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

**Page:** 675

---

## [Please more bureaucracy on package registrations!](https://discourse.julialang.org/t/please-more-bureaucracy-on-package-registrations/100018)

<div class="topic-metadata">

**Author:** [@Eben60](https://discourse.julialang.org/u/Eben60)\
**Replies:** 20\
**Last updated:** [June 11, 2023, 11:24am UTC](https://discourse.julialang.org/t/please-more-bureaucracy-on-package-registrations/100018 "2023-06-11T11:24:56Z")

</div>

BTW, is there a smiley for tongue-in-cheek? Inspired by the The present and the future of package registration thread, especially by the response by @Tamas\_Papp to my comment and by the reference to this PR Check that …

---

## [The present and the future of package registration](https://discourse.julialang.org/t/the-present-and-the-future-of-package-registration/99890)

<div class="topic-metadata">

**Author:** [@essenciary](https://discourse.julialang.org/u/essenciary)\
**Replies:** 80\
**Last updated:** [June 11, 2023, 11:18am UTC](https://discourse.julialang.org/t/the-present-and-the-future-of-package-registration/99890 "2023-06-11T11:18:12Z")

</div>

This has been on my mind for some time, but now that my package registration PR has been closed, I finally decided to take a few minutes to share. TLDR; Due to the fact that Julia packages are registered at “top level”…

---

## [How to plot a spectrum with dB as y-axis with PythonPlot](https://discourse.julialang.org/t/how-to-plot-a-spectrum-with-db-as-y-axis-with-pythonplot/100172)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 1\
**Last updated:** [June 11, 2023, 8:01am UTC](https://discourse.julialang.org/t/how-to-plot-a-spectrum-with-db-as-y-axis-with-pythonplot/100172 "2023-06-11T08:01:15Z")

</div>

I am using PythonPlot and want to have a logarithmic y axis formatted in dezibel (dB). In Python I could use the following code: from UliEngineering.Math.Decibel import \* import matplotlib.ticker as mtick def decibel\_fo…

---

## [How to speed up this ODEs solving code?](https://discourse.julialang.org/t/how-to-speed-up-this-odes-solving-code/100160)

<div class="topic-metadata">

**Author:** [@kkipi](https://discourse.julialang.org/u/kkipi)\
**Replies:** 5\
**Last updated:** [June 11, 2023, 7:42am UTC](https://discourse.julialang.org/t/how-to-speed-up-this-odes-solving-code/100160 "2023-06-11T07:42:36Z")

</div>

I am trying to solve a matrix ODE as: using StaticArrays using LinearOperators using BenchmarkTools using OrdinaryDiffEq using LinearAlgebra using Roots; si=SMatrix{2, 2, Complex{Float64}}(\[1 0;0 1\]); sx=SMatrix{2, 2, …

---

## [Unpacking a named tuple using field names and slurping?](https://discourse.julialang.org/t/unpacking-a-named-tuple-using-field-names-and-slurping/100035)

<div class="topic-metadata">

**Author:** [@onetonfoot](https://discourse.julialang.org/u/onetonfoot)\
**Replies:** 15\
**Last updated:** [June 11, 2023, 6:24am UTC](https://discourse.julialang.org/t/unpacking-a-named-tuple-using-field-names-and-slurping/100035 "2023-06-11T06:24:07Z")

</div>

I’ve got a named tuple with a bunch of fields and I’d like to unpack certain fields based on the key and slurp the remaining. r = (x=1, y=2, z=3) (y, rest...) = r The trouble with the above is that it will unpack bas…

---

## [Meaning of Incidence matrix?](https://discourse.julialang.org/t/meaning-of-incidence-matrix/100141)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 3\
**Last updated:** [June 11, 2023, 5:05am UTC](https://discourse.julialang.org/t/meaning-of-incidence-matrix/100141 "2023-06-11T05:05:45Z")

</div>

I defined a nonlinear model and linearized it. I get the following result: julia\> simplified\_sys Model sys with 3 equations States (3): ω(t) \[defaults to 1.04286\] Uest(t) \[defaults to 9.0\] Pgc(t) \[defaults to 2.46…

---

## [Performance of hasmethod vs try-catch on MethodError](https://discourse.julialang.org/t/performance-of-hasmethod-vs-try-catch-on-methoderror/99827)

<div class="topic-metadata">

**Author:** [@MilesCranmer](https://discourse.julialang.org/u/MilesCranmer)\
**Replies:** 22\
**Last updated:** [June 11, 2023, 4:31am UTC](https://discourse.julialang.org/t/performance-of-hasmethod-vs-try-catch-on-methoderror/99827 "2023-06-11T04:31:24Z")

</div>

To help me better understand Julia’s performance behavior, I am trying to understand the large difference between two strategies for checking for undefined methods: hasmethod vs try-catch. I’ve read through Are exceptio…

---

## [Activation functions in NeuralPDE](https://discourse.julialang.org/t/activation-functions-in-neuralpde/100153)

<div class="topic-metadata">

**Author:** [@Ethan\_Tran](https://discourse.julialang.org/u/Ethan_Tran)\
**Replies:** 5\
**Last updated:** [June 11, 2023, 3:45am UTC](https://discourse.julialang.org/t/activation-functions-in-neuralpde/100153 "2023-06-11T03:45:30Z")

</div>

Hi everyone, I am trying to use NeuralPDE to solve ODE systems. I would like to ask that whether NeuralPDE provide different activation function like Softmax, Tanh or just only Sigmoid? If yes, how could I find the in…

---

## [Why are functions that are never called getting compiled?](https://discourse.julialang.org/t/why-are-functions-that-are-never-called-getting-compiled/100072)

<div class="topic-metadata">

**Author:** [@user664303](https://discourse.julialang.org/u/user664303)\
**Replies:** 8\
**Last updated:** [June 10, 2023, 10:25pm UTC](https://discourse.julialang.org/t/why-are-functions-that-are-never-called-getting-compiled/100072 "2023-06-10T22:25:28Z")

</div>

Previously I asked about, and solved, a problem with compilation of a function inside generated code - the problem was that multiple instances of a function were getting compiled without being called. I would like to avo…

---

## [Error using an exponential function in a Hamiltonian](https://discourse.julialang.org/t/error-using-an-exponential-function-in-a-hamiltonian/99540)

<div class="topic-metadata">

**Author:** [@Anil\_Kumar](https://discourse.julialang.org/u/Anil_Kumar)\
**Replies:** 4\
**Last updated:** [June 11, 2023, 1:18am UTC](https://discourse.julialang.org/t/error-using-an-exponential-function-in-a-hamiltonian/99540 "2023-06-11T01:18:03Z")

</div>

I am trying to modify a model with some extra terms, but getting an error. using QuantumCumulants using OrdinaryDiffEq, ModelingToolkit hc = FockSpace(:cavity) hm = FockSpace(:motion) h = hc ⊗ hm t = (0.0,10000.0) @qnum…

---

## [GeoMakie: Could not find font regular, using TeX Gyre Heros Makie](https://discourse.julialang.org/t/geomakie-could-not-find-font-regular-using-tex-gyre-heros-makie/100092)

<div class="topic-metadata">

**Author:** [@thunderclouds](https://discourse.julialang.org/u/thunderclouds)\
**Replies:** 4\
**Last updated:** [June 11, 2023, 12:24am UTC](https://discourse.julialang.org/t/geomakie-could-not-find-font-regular-using-tex-gyre-heros-makie/100092 "2023-06-11T00:24:32Z")

</div>

I have a question about the fonts in GeoMakie.jl. When I run the following sample code, I get the error “Warning: Could not find font regular, using TeX Gyre Heros Makie”. It seems that this error occurs at the timing w…

---

## [Tab completion and Unicode names for values not in Julia Documentation](https://discourse.julialang.org/t/tab-completion-and-unicode-names-for-values-not-in-julia-documentation/100152)

<div class="topic-metadata">

**Author:** [@daler6](https://discourse.julialang.org/u/daler6)\
**Replies:** 1\
**Last updated:** [June 10, 2023, 10:17pm UTC](https://discourse.julialang.org/t/tab-completion-and-unicode-names-for-values-not-in-julia-documentation/100152 "2023-06-10T22:17:14Z")

</div>

I am using the book Julia as a Second Language and at points it uses symbols with Unicode points not included in the Julia documentation (see Unicode Input · The Julia Language). Specifically, it uses several from the Bo…

---

## [Inconsistent results when using Threads.@threads in a loop](https://discourse.julialang.org/t/inconsistent-results-when-using-threads-threads-in-a-loop/100134)

<div class="topic-metadata">

**Author:** [@fedcer](https://discourse.julialang.org/u/fedcer)\
**Replies:** 17\
**Last updated:** [June 10, 2023, 8:21pm UTC](https://discourse.julialang.org/t/inconsistent-results-when-using-threads-threads-in-a-loop/100134 "2023-06-10T20:21:05Z")

</div>

Hi all, I’m running into the problem of having inconsistent outputs when using the Threads.@threads macro on a loop and I struggle to understand why it’s happening. Here is a MWE function function coefs(N) v = zero…

---

## [PackageCompiler - Understand how compilation works](https://discourse.julialang.org/t/packagecompiler-understand-how-compilation-works/100142)

<div class="topic-metadata">

**Author:** [@iskyd](https://discourse.julialang.org/u/iskyd)\
**Replies:** 3\
**Last updated:** [June 10, 2023, 6:01pm UTC](https://discourse.julialang.org/t/packagecompiler-understand-how-compilation-works/100142 "2023-06-10T18:01:54Z")

</div>

I’m creating an app using PackageCompiler.jl as described here I’m trying to create an executable of a simple backend application. PackageCompiler works fine since I am able to generate a binary to run my application. W…

---

## [Maximum timestep in DIfferential solver](https://discourse.julialang.org/t/maximum-timestep-in-differential-solver/100135)

<div class="topic-metadata">

**Author:** [@Sarthak\_Choudhury](https://discourse.julialang.org/u/Sarthak_Choudhury)\
**Replies:** 4\
**Last updated:** [June 10, 2023, 5:11pm UTC](https://discourse.julialang.org/t/maximum-timestep-in-differential-solver/100135 "2023-06-10T17:11:19Z")

</div>

Hi, I am currently solving an ODE in DifferentialEquations.jl which has explicit time dependence. I arrive at a solution for a larger time t\_{max} with the solution saved at 1000 time points in between. Now I want to zo…

---

## [Is there a symbolic Integrator](https://discourse.julialang.org/t/is-there-a-symbolic-integrator/100140)

<div class="topic-metadata">

**Author:** [@bombadil224](https://discourse.julialang.org/u/bombadil224)\
**Replies:** 1\
**Last updated:** [June 10, 2023, 4:47pm UTC](https://discourse.julialang.org/t/is-there-a-symbolic-integrator/100140 "2023-06-10T16:47:17Z")

</div>

I have been writing a Homotopy approximation method solver for differential equations. This requires the use of integration, So far I have been using a very simple function for the integration of polynomials. This is cle…

---

## [Simple question about Julia types](https://discourse.julialang.org/t/simple-question-about-julia-types/100077)

<div class="topic-metadata">

**Author:** [@mmv](https://discourse.julialang.org/u/mmv)\
**Replies:** 11\
**Last updated:** [June 10, 2023, 2:25pm UTC](https://discourse.julialang.org/t/simple-question-about-julia-types/100077 "2023-06-10T14:25:13Z")

</div>

Hi! Given the following statements are true: julia\> Matrix \<: AbstractMatrix true julia\> Float64 \<: Number true why is it that julia\> Matrix{Float64} \<: AbstractMatrix{Number} false ?

---

## [Usage of imfilter() with specified type](https://discourse.julialang.org/t/usage-of-imfilter-with-specified-type/100137)

<div class="topic-metadata">

**Author:** [@Fatalon](https://discourse.julialang.org/u/Fatalon)\
**Replies:** 2\
**Last updated:** [June 10, 2023, 1:39pm UTC](https://discourse.julialang.org/t/usage-of-imfilter-with-specified-type/100137 "2023-06-10T13:39:36Z")

</div>

Hey there, I am trying to apply a simple gaussian blur to an image of type Matrix{Gray{N0f8}}, but recognized that the returned type is Matrix{Gray{Float64}}. . After looking up the documentation at Function reference …

---

## [Counting in dataframes](https://discourse.julialang.org/t/counting-in-dataframes/99907)

<div class="topic-metadata">

**Author:** [@optimist](https://discourse.julialang.org/u/optimist)\
**Replies:** 7\
**Last updated:** [June 7, 2023, 1:49pm UTC](https://discourse.julialang.org/t/counting-in-dataframes/99907 "2023-06-07T13:49:21Z")

</div>

I have a dataframe in which I need to count the number of occurences of values in a given list. Suppose I have a dataframe df: df= DataFrame(:B1 =\> \[1,1,2,2,3,4,5\], :B2 =\> \[1,7,7,2,2,5,5\],:B3 =\> \[2,2,2,3,3,3,3\] ) 7×3 …

---

## [What are the essential differences between \`include\` a file and \`using\` a module?](https://discourse.julialang.org/t/what-are-the-essential-differences-between-include-a-file-and-using-a-module/99798)

<div class="topic-metadata">

**Author:** [@WuSiren](https://discourse.julialang.org/u/WuSiren)\
**Replies:** 3\
**Last updated:** [June 10, 2023, 11:40am UTC](https://discourse.julialang.org/t/what-are-the-essential-differences-between-include-a-file-and-using-a-module/99798 "2023-06-10T11:40:29Z")

</div>

What are the essential differences between the following two workflows and what are their respective usage scenarios? Or in another word, what’s the necessity for writing a module instead of a plain .jl file? Write som…

---

## [How to set environment for local Julia package in module](https://discourse.julialang.org/t/how-to-set-environment-for-local-julia-package-in-module/100106)

<div class="topic-metadata">

**Author:** [@Torkel](https://discourse.julialang.org/u/Torkel)\
**Replies:** 8\
**Last updated:** [June 10, 2023, 10:37am UTC](https://discourse.julialang.org/t/how-to-set-environment-for-local-julia-package-in-module/100106 "2023-06-10T10:37:27Z")

</div>

I have a project which depends on a private module I am having. I have a folder in which I have my project script (“playground.jl”), which imports my module MyModule and its content. How do I make environments work for M…

---

## [MCMC Sampling Method Overview/Comparison?](https://discourse.julialang.org/t/mcmc-sampling-method-overview-comparison/88496)

<div class="topic-metadata">

**Author:** [@Alec\_Loudenback](https://discourse.julialang.org/u/Alec_Loudenback)\
**Replies:** 7\
**Last updated:** [June 10, 2023, 5:50am UTC](https://discourse.julialang.org/t/mcmc-sampling-method-overview-comparison/88496 "2023-06-10T05:50:19Z")

</div>

Is there a reference that compares the different sampling techniques available for Turing.jl? I don’t see a consistently preferred chain and it’s not clear to me (a beginner bayesian) why one would prefer a given sampler…

---

## [Very large performance difference between Turing and Stan \[Gaussian Process\]](https://discourse.julialang.org/t/very-large-performance-difference-between-turing-and-stan-gaussian-process/93663)

<div class="topic-metadata">

**Author:** [@jdossgollin](https://discourse.julialang.org/u/jdossgollin)\
**Replies:** 9\
**Last updated:** [June 10, 2023, 5:42am UTC](https://discourse.julialang.org/t/very-large-performance-difference-between-turing-and-stan-gaussian-process/93663 "2023-06-10T05:42:59Z")

</div>

A student I’m working with is working on a Gaussian Process model in Turing, but it was very slow. Out of frustration, they reimplemented in stan and it’s much faster. For context, it fits (1000 samples from 1 chain) in …

---

## [Warning: Linking two modules of different target triples: 'bcloader' ... 'start'](https://discourse.julialang.org/t/warning-linking-two-modules-of-different-target-triples-bcloader-start/93864)

<div class="topic-metadata">

**Author:** [@albheim](https://discourse.julialang.org/u/albheim)\
**Replies:** 5\
**Last updated:** [June 10, 2023, 4:28am UTC](https://discourse.julialang.org/t/warning-linking-two-modules-of-different-target-triples-bcloader-start/93864 "2023-06-10T04:28:18Z")

</div>

Started getting the warnings warning: Linking two modules of different target triples: 'bcloader' is 'x86\_64-unknown-linux-gnu' whereas 'start' is 'x86\_64-linux-gnu' warning: Linking two modules of different target tri…

---

## [Repl immediately crashes in VSCode](https://discourse.julialang.org/t/repl-immediately-crashes-in-vscode/100078)

<div class="topic-metadata">

**Author:** [@slwu89](https://discourse.julialang.org/u/slwu89)\
**Replies:** 6\
**Last updated:** [June 9, 2023, 11:39pm UTC](https://discourse.julialang.org/t/repl-immediately-crashes-in-vscode/100078 "2023-06-09T23:39:20Z")

</div>

Hi, when opening Julia from the command palette (Julia: start REPL) it immediately crashes/closes too fast for me to see any errors. I followed the FAQ at FAQ · Julia in VS Code to use Julia: Connect external repl which …

---

## [Simple Enzyme AD on CUDA GPU](https://discourse.julialang.org/t/simple-enzyme-ad-on-cuda-gpu/99966)

<div class="topic-metadata">

**Author:** [@Thaegy](https://discourse.julialang.org/u/Thaegy)\
**Replies:** 5\
**Last updated:** [June 9, 2023, 11:00pm UTC](https://discourse.julialang.org/t/simple-enzyme-ad-on-cuda-gpu/99966 "2023-06-09T23:00:08Z")

</div>

Hi there, I have just started thinking about moving some of my JAX code to Julia and wanted to have a go using Enzyme for my AD. I am looking to make use of CUDA GPUs. I have started with a simple program to verify thin…

---

## [Instability detected in solving ODE with DifferentialEquations.jl](https://discourse.julialang.org/t/instability-detected-in-solving-ode-with-differentialequations-jl/99792)

<div class="topic-metadata">

**Author:** [@Rezair](https://discourse.julialang.org/u/Rezair)\
**Replies:** 7\
**Last updated:** [June 9, 2023, 10:23pm UTC](https://discourse.julialang.org/t/instability-detected-in-solving-ode-with-differentialequations-jl/99792 "2023-06-09T22:23:22Z")

</div>

I am trying to solve an equation in Julia but I get Unstable retcode, I have solved the same eqaution in MATLAB with no issues. here is a simplified version of the code: using DifferentialEquations struct RosslerMSF …

---

## [Perform Bayesian estimations of ODE parameters when variables were not measured simultaneously](https://discourse.julialang.org/t/perform-bayesian-estimations-of-ode-parameters-when-variables-were-not-measured-simultaneously/100033)

<div class="topic-metadata">

**Author:** [@zeyang.sun](https://discourse.julialang.org/u/zeyang.sun)\
**Replies:** 3\
**Last updated:** [June 9, 2023, 10:08pm UTC](https://discourse.julialang.org/t/perform-bayesian-estimations-of-ode-parameters-when-variables-were-not-measured-simultaneously/100033 "2023-06-09T22:08:27Z")

</div>

Greetings everyone! Recently I need to use Bayesian method to estimate the parameters of a chemical kinetic model which can be described by ordinary differential equations. I found Turing.jl or DiffeqBayes.jl might be t…

---

## [This month in Julia world - 2023-05](https://discourse.julialang.org/t/this-month-in-julia-world-2023-05/99634)

<div class="topic-metadata">

**Author:** [@Krastanov](https://discourse.julialang.org/u/Krastanov)\
**Replies:** 20\
**Last updated:** [June 9, 2023, 10:04pm UTC](https://discourse.julialang.org/t/this-month-in-julia-world-2023-05/99634 "2023-06-09T22:04:04Z")

</div>

There was a call to action for someone to make a newsletter that lists interesting developments in the Julia world, in order to communicate improvements to the language that are not visible unless you track Github and Sl…

---

## [Should a reassigning begin block execute before a variable's value is set?](https://discourse.julialang.org/t/should-a-reassigning-begin-block-execute-before-a-variables-value-is-set/100038)

<div class="topic-metadata">

**Author:** [@Benny](https://discourse.julialang.org/u/Benny)\
**Replies:** 26\
**Last updated:** [June 9, 2023, 9:47pm UTC](https://discourse.julialang.org/t/should-a-reassigning-begin-block-execute-before-a-variables-value-is-set/100038 "2023-06-09T21:47:20Z")

</div>

A youtuber leddoo posed an interesting “bug” (in some other language). It’s hard to explain in words but it has to do with whether a value is set before or after a subsequent block executes. Commenters actually were not …

[Previous page](https://discourse.julialang.org/latest.md?page=673)

[Next page](https://discourse.julialang.org/latest.md?page=675)