# Latest

**URL:** https://discourse.julialang.org/latest.md?page=439

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

**Page:** 440

---

## [Downgrade CI fails with "persistent task" Aqua error](https://discourse.julialang.org/t/downgrade-ci-fails-with-persistent-task-aqua-error/112644)

<div class="topic-metadata">

**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 4\
**Last updated:** [April 7, 2024, 9:42pm UTC](https://discourse.julialang.org/t/downgrade-ci-fails-with-persistent-task-aqua-error/112644 "2024-04-07T21:42:04Z")

</div>

The CellListMap.jl package Downgrade CI is failing with the error below. Can some provide any clue on how to find what is going wrong? I’m not sure what the persistent\_task erorr is exactly, and less why it could appear…

---

## [DrWatson and github](https://discourse.julialang.org/t/drwatson-and-github/44060)

<div class="topic-metadata">

**Author:** [@erlebach](https://discourse.julialang.org/u/erlebach)\
**Replies:** 0\
**Last updated:** [July 31, 2020, 9:09pm UTC](https://discourse.julialang.org/t/drwatson-and-github/44060 "2020-07-31T21:09:01Z")

</div>

I am taking my first steps with Dr.Watson. Any words of wisdom to share? Here is a question: When using @tagsave, I am saving and committing at the same time. But its utility depends on me making sure that the source co…

---

## [Questions related to DrWatson](https://discourse.julialang.org/t/questions-related-to-drwatson/53481)

<div class="topic-metadata">

**Author:** [@dapz](https://discourse.julialang.org/u/dapz)\
**Replies:** 0\
**Last updated:** [January 17, 2021, 11:57am UTC](https://discourse.julialang.org/t/questions-related-to-drwatson/53481 "2021-01-17T11:57:44Z")

</div>

Hi, I just discovered the DrWatson package and I’m curious to see if I could use that in the future (to replace my “custom” package, which works OK until now but is not really clean/documented/extensible… :D). With my p…

---

## [Debugging saving error from tagsave DrWatson.jl](https://discourse.julialang.org/t/debugging-saving-error-from-tagsave-drwatson-jl/57301)

<div class="topic-metadata">

**Author:** [@Michaela\_Maskova](https://discourse.julialang.org/u/Michaela_Maskova)\
**Replies:** 0\
**Last updated:** [March 16, 2021, 1:30pm UTC](https://discourse.julialang.org/t/debugging-saving-error-from-tagsave-drwatson-jl/57301 "2021-03-16T13:30:06Z")

</div>

Hi, I’m having trouble understanding an error happening when running a script. It is part of a larger project, therefore it’s kinda hard to add an example. But what happens is that I run a model, train it and try to save…

---

## [Is there a built-in function for the natural length of a segment represented by an iterator?](https://discourse.julialang.org/t/is-there-a-built-in-function-for-the-natural-length-of-a-segment-represented-by-an-iterator/112414)

<div class="topic-metadata">

**Author:** [@homocomputeris](https://discourse.julialang.org/u/homocomputeris)\
**Replies:** 12\
**Last updated:** [April 4, 2024, 10:26am UTC](https://discourse.julialang.org/t/is-there-a-built-in-function-for-the-natural-length-of-a-segment-represented-by-an-iterator/112414 "2024-04-04T10:26:09Z")

</div>

Well, it’s rather simple, but maybe there is already a built-in function to do calculate this? natural\_length(s) = s\[end\]-s\[begin\] natural\_length((1,10)) natural\_length((1:10)) It annoying to copy-paste this snippet w…

---

## [How to position widgets correctly with the Gtk4 grid](https://discourse.julialang.org/t/how-to-position-widgets-correctly-with-the-gtk4-grid/112617)

<div class="topic-metadata">

**Author:** [@Alex\_73](https://discourse.julialang.org/u/Alex_73)\
**Replies:** 2\
**Last updated:** [April 7, 2024, 5:16pm UTC](https://discourse.julialang.org/t/how-to-position-widgets-correctly-with-the-gtk4-grid/112617 "2024-04-07T17:16:24Z")

</div>

I’m starting to study Gtk4 made available by https://juliagtk.github.io/Gtk4.jl/dev/manual/layout/#GtkGrid And I managed to run the example: win = GtkWindow("A new window") g = GtkGrid() a = GtkEntry() # a widget for …

---

## [Why are some packages grayed out in JuliaHub search results?](https://discourse.julialang.org/t/why-are-some-packages-grayed-out-in-juliahub-search-results/112290)

<div class="topic-metadata">

**Author:** [@matthias314](https://discourse.julialang.org/u/matthias314)\
**Replies:** 4\
**Last updated:** [April 7, 2024, 5:15pm UTC](https://discourse.julialang.org/t/why-are-some-packages-grayed-out-in-juliahub-search-results/112290 "2024-04-07T17:15:16Z")

</div>

I registered the packages SimplicialSets.jl and SymbolicSigns.jl almost three weeks ago. Installing them from the registry works fine, and the JuliaHub links in the previous sentence also work. However, when I search for…

---

## [Continue solving ODE problem when using NeuralPDE.NNODE](https://discourse.julialang.org/t/continue-solving-ode-problem-when-using-neuralpde-nnode/101580)

<div class="topic-metadata">

**Author:** [@Ethan\_Tran](https://discourse.julialang.org/u/Ethan_Tran)\
**Replies:** 2\
**Last updated:** [April 7, 2024, 5:12pm UTC](https://discourse.julialang.org/t/continue-solving-ode-problem-when-using-neuralpde-nnode/101580 "2024-04-07T17:12:27Z")

</div>

I tried to continue solving by using the previous weight as the initial weight for the new one. But the loss for the first iteration of the new one is higher than the final loss of the previous one. My code is below: u…

---

## [Associativity of promote\_type](https://discourse.julialang.org/t/associativity-of-promote-type/109958)

<div class="topic-metadata">

**Author:** [@odow](https://discourse.julialang.org/u/odow)\
**Replies:** 6\
**Last updated:** [April 7, 2024, 3:14pm UTC](https://discourse.julialang.org/t/associativity-of-promote-type/109958 "2024-04-07T15:14:45Z")

</div>

I found this via a bug report in JuMP: Error vcat(::NonlinearExpr, ::VariableRef, ::Float64) · Issue #3671 · jump-dev/JuMP.jl · GitHub. promote\_type has an implicit assumption of associativity, i.e.: promote\_type(A, pr…

---

## [DAE mass matrix formulation fails but implicit formulation works](https://discourse.julialang.org/t/dae-mass-matrix-formulation-fails-but-implicit-formulation-works/104940)

<div class="topic-metadata">

**Author:** [@aaliqureshi](https://discourse.julialang.org/u/aaliqureshi)\
**Replies:** 19\
**Last updated:** [April 7, 2024, 3:32pm UTC](https://discourse.julialang.org/t/dae-mass-matrix-formulation-fails-but-implicit-formulation-works/104940 "2024-04-07T15:32:27Z")

</div>

This question links to my previous post. I am simulating a DAE system and noticed that the mass matrix based formulation fails but the implicit DAE formulation works fine. Is this a bug or is there something else goi…

---

## [Embedding Julia through C conversion using LLVM IR and neural network transforms to convert Julia to embedable C](https://discourse.julialang.org/t/embedding-julia-through-c-conversion-using-llvm-ir-and-neural-network-transforms-to-convert-julia-to-embedable-c/112614)

<div class="topic-metadata">

**Author:** [@Allan\_Baker](https://discourse.julialang.org/u/Allan_Baker)\
**Replies:** 4\
**Last updated:** [April 7, 2024, 2:31pm UTC](https://discourse.julialang.org/t/embedding-julia-through-c-conversion-using-llvm-ir-and-neural-network-transforms-to-convert-julia-to-embedable-c/112614 "2024-04-07T14:31:58Z")

</div>

I would love to be able to use Julia to design embedable control systems and signal processing architectures. Since Julia can’t cross compile to embedable DSPs or SoCs and may not have the stability that critical system…

---

## [ContinuousDataDrivenProblem stuck if no time derivatives provided](https://discourse.julialang.org/t/continuousdatadrivenproblem-stuck-if-no-time-derivatives-provided/105758)

<div class="topic-metadata">

**Author:** [@Maxime-Fantino](https://discourse.julialang.org/u/Maxime-Fantino)\
**Replies:** 1\
**Last updated:** [April 7, 2024, 1:44pm UTC](https://discourse.julialang.org/t/continuousdatadrivenproblem-stuck-if-no-time-derivatives-provided/105758 "2024-04-07T13:44:55Z")

</div>

Hello, I am trying to do inference on particle dynamics with data coming from a simulator, using the DataDrivenDiffEq package. Similarly to what is done in the documentation (Automatically Discover Missing Physics by E…

---

## [Model discovery using Sparse Regression on UDE model](https://discourse.julialang.org/t/model-discovery-using-sparse-regression-on-ude-model/106698)

<div class="topic-metadata">

**Author:** [@gsh19](https://discourse.julialang.org/u/gsh19)\
**Replies:** 1\
**Last updated:** [April 7, 2024, 1:44pm UTC](https://discourse.julialang.org/t/model-discovery-using-sparse-regression-on-ude-model/106698 "2024-04-07T13:44:05Z")

</div>

Hi everyone, I am working on modeling the unknown physics of a non-autonomous system. The system has 5 states and 2 control inputs. The dynamics of states 1 to 3 are known precisely but those of states 4 and 5 are unkno…

---

## [Tips for Estimating Non-linear Latent SDE](https://discourse.julialang.org/t/tips-for-estimating-non-linear-latent-sde/104326)

<div class="topic-metadata">

**Author:** [@dleather](https://discourse.julialang.org/u/dleather)\
**Replies:** 1\
**Last updated:** [April 7, 2024, 1:42pm UTC](https://discourse.julialang.org/t/tips-for-estimating-non-linear-latent-sde/104326 "2024-04-07T13:42:20Z")

</div>

I was hoping to use Turing.jl alongside DifferentialEquations.jl to estimate a partially observable SDE via quasi-likelihood methods. Being new to continuous-time models, I was hoping to get some suggestions on the most …

---

## [Callbacks after integration step but before integration function](https://discourse.julialang.org/t/callbacks-after-integration-step-but-before-integration-function/103676)

<div class="topic-metadata">

**Author:** [@jondavis847](https://discourse.julialang.org/u/jondavis847)\
**Replies:** 3\
**Last updated:** [April 7, 2024, 1:38pm UTC](https://discourse.julialang.org/t/callbacks-after-integration-step-but-before-integration-function/103676 "2024-04-07T13:38:51Z")

</div>

As an alternative to DAE definition or SavingCallbacks, I’m using a FunctionCallingCallback with DifferentialEquations.jl to solve algebraic states for an ODE. The callback would need to occur after the integration times…

---

## [Help modeling advection-diffusion equation with ModelingToolkit.jl](https://discourse.julialang.org/t/help-modeling-advection-diffusion-equation-with-modelingtoolkit-jl/105028)

<div class="topic-metadata">

**Author:** [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Replies:** 27\
**Last updated:** [April 7, 2024, 1:36pm UTC](https://discourse.julialang.org/t/help-modeling-advection-diffusion-equation-with-modelingtoolkit-jl/105028 "2024-04-07T13:36:10Z")

</div>

First time trying to use ModelingToolkit.jl in a project. Appreciate if someone can help with a simple 1D example of advection-diffusion: R \\frac{\\partial c}{\\partial t} = D \\frac{\\partial^2 c}{\\partial x^2} - v \\frac{\\…

---

## [NeuralPDE debuging: is it posible to get the loss of a point in the domain?](https://discourse.julialang.org/t/neuralpde-debuging-is-it-posible-to-get-the-loss-of-a-point-in-the-domain/105427)

<div class="topic-metadata">

**Author:** [@Knud\_Sorensen](https://discourse.julialang.org/u/Knud_Sorensen)\
**Replies:** 2\
**Last updated:** [April 7, 2024, 1:32pm UTC](https://discourse.julialang.org/t/neuralpde-debuging-is-it-posible-to-get-the-loss-of-a-point-in-the-domain/105427 "2024-04-07T13:32:27Z")

</div>

Hi. I am solving some differential equations with NeuralPDE and the solutions don’t look like expected. So, I really want to plot the loss at every point in the domain to see what is going on. Is there any way to get t…

---

## [Example for integro-differential equation with NeuralPDE does not run](https://discourse.julialang.org/t/example-for-integro-differential-equation-with-neuralpde-does-not-run/104603)

<div class="topic-metadata">

**Author:** [@TommasoStentella](https://discourse.julialang.org/u/TommasoStentella)\
**Replies:** 2\
**Last updated:** [April 7, 2024, 1:24pm UTC](https://discourse.julialang.org/t/example-for-integro-differential-equation-with-neuralpde-does-not-run/104603 "2024-04-07T13:24:15Z")

</div>

I am trying to use NeuralPDE for solving an integro-differential equation with the aim of later embedding a neural network in it. To begin with, I tried the example I found in the documentation, but it gives me an error: …

---

## [Sorting a StructArray variable faster and how to update values?](https://discourse.julialang.org/t/sorting-a-structarray-variable-faster-and-how-to-update-values/112621)

<div class="topic-metadata">

**Author:** [@Ahmed\_Salih](https://discourse.julialang.org/u/Ahmed_Salih)\
**Replies:** 6\
**Last updated:** [April 7, 2024, 1:06pm UTC](https://discourse.julialang.org/t/sorting-a-structarray-variable-faster-and-how-to-update-values/112621 "2024-04-07T13:06:16Z")

</div>

Hello! I have a runnable MWE here, put into a small module to easily redefine struct as needed: module ParticleSorting export sort\_particles\_by\_density using StructArrays using StaticArrays using BenchmarkTools using…

---

## [False warning in VSCode](https://discourse.julialang.org/t/false-warning-in-vscode/112638)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 3\
**Last updated:** [April 7, 2024, 12:47pm UTC](https://discourse.julialang.org/t/false-warning-in-vscode/112638 "2024-04-07T12:47:21Z")

</div>

I have the following code: mutable struct KiteObserver length::Vector{Float64} elevation::Vector{Float64} end function KiteObserver() KiteObserver(Float64\[\], Float64\[\]) end I get the warning: Possible meth…

---

## [How to define parameters of a model built by Lux.jl in ModelingToolkit.jl and perform optimization or computation?](https://discourse.julialang.org/t/how-to-define-parameters-of-a-model-built-by-lux-jl-in-modelingtoolkit-jl-and-perform-optimization-or-computation/112631)

<div class="topic-metadata">

**Author:** [@chooron](https://discourse.julialang.org/u/chooron)\
**Replies:** 2\
**Last updated:** [April 7, 2024, 12:40pm UTC](https://discourse.julialang.org/t/how-to-define-parameters-of-a-model-built-by-lux-jl-in-modelingtoolkit-jl-and-perform-optimization-or-computation/112631 "2024-04-07T12:40:11Z")

</div>

I’ve just started using ModelingToolkit.jl recently, but I would like to describe and compute an ODE problem with a neural network model using ModelingToolkit.jl. I would like to start by testing the feasibility of this…

---

## [Parameters optimization with pinns of a RC model](https://discourse.julialang.org/t/parameters-optimization-with-pinns-of-a-rc-model/104019)

<div class="topic-metadata">

**Author:** [@Marco\_Nesta](https://discourse.julialang.org/u/Marco_Nesta)\
**Replies:** 14\
**Last updated:** [April 7, 2024, 12:16pm UTC](https://discourse.julialang.org/t/parameters-optimization-with-pinns-of-a-rc-model/104019 "2024-04-07T12:16:11Z")

</div>

I’m trying to optimize the parameters of this first state of a rc model using NeuralPDE but I get error. what am I doing wrong? using NeuralPDE, Lux, ModelingToolkit, Optimization, OptimizationOptimJL, OrdinaryDiffEq, …

---

## [Lipschitz continuity -- Neural ODEs](https://discourse.julialang.org/t/lipschitz-continuity-neural-odes/108463)

<div class="topic-metadata">

**Author:** [@RahulManavalan](https://discourse.julialang.org/u/RahulManavalan)\
**Replies:** 2\
**Last updated:** [April 7, 2024, 12:13pm UTC](https://discourse.julialang.org/t/lipschitz-continuity-neural-odes/108463 "2024-04-07T12:13:28Z")

</div>

Here’s a open ended topic that I haven’t seen people mention, explicitly in literature. In order to integrate neural ODEs, there needs to be guarentees regarding the existence of its solutions. And any arbitrary NN appr…

---

## [How to evaluate multivariate log normal distribution at arbitrary point?](https://discourse.julialang.org/t/how-to-evaluate-multivariate-log-normal-distribution-at-arbitrary-point/112608)

<div class="topic-metadata">

**Author:** [@structural](https://discourse.julialang.org/u/structural)\
**Replies:** 2\
**Last updated:** [April 7, 2024, 9:46am UTC](https://discourse.julialang.org/t/how-to-evaluate-multivariate-log-normal-distribution-at-arbitrary-point/112608 "2024-04-07T09:46:47Z")

</div>

Suppose I have the following distribution over two variables dist = MvLogNormal(mean\_a\_b, cov\_a\_b) Suppose h is an array of dimension 1000\\times 2. For each row of array h, the first entry represents the rank of the …

---

## [Release strategy for juliac?](https://discourse.julialang.org/t/release-strategy-for-juliac/112563)

<div class="topic-metadata">

**Author:** [@oheil](https://discourse.julialang.org/u/oheil)\
**Replies:** 30\
**Last updated:** [April 7, 2024, 10:56am UTC](https://discourse.julialang.org/t/release-strategy-for-juliac/112563 "2024-04-07T10:56:46Z")

</div>

In another thread @mbauman said: which, of course, triggered my inner excitement and I had to open this discussion. At the time, this, the juliac, is ready, the core Julia people together with us, the community, shou…

---

## [I've developed a new Perlin-style noise. Can you improve it?](https://discourse.julialang.org/t/ive-developed-a-new-perlin-style-noise-can-you-improve-it/112618)

<div class="topic-metadata">

**Author:** [@Tarny\_GG\_Channie](https://discourse.julialang.org/u/Tarny_GG_Channie)\
**Replies:** 3\
**Last updated:** [April 7, 2024, 10:11am UTC](https://discourse.julialang.org/t/ive-developed-a-new-perlin-style-noise-can-you-improve-it/112618 "2024-04-07T10:11:32Z")

</div>

This is a simplified version of the OpenSimplex noise (and all its versions). seed = 0x120367e73b381c44 #Modified version of random number generator by Bernard Widynski. https://arxiv.org/abs/2004.06278 get\_random\_n…

---

## [Update URL of registered package](https://discourse.julialang.org/t/update-url-of-registered-package/112637)

<div class="topic-metadata">

**Author:** [@JanLeppert](https://discourse.julialang.org/u/JanLeppert)\
**Replies:** 1\
**Last updated:** [April 7, 2024, 10:01am UTC](https://discourse.julialang.org/t/update-url-of-registered-package/112637 "2024-04-07T10:01:24Z")

</div>

I moved some of my projects to an organization and I updated the repo URL in the general registry three days ago, as suggested in GitHub - JuliaRegistries/General: The official registry of general Julia packages. All thr…

---

## [Annotating only a few points with StatsPlots](https://discourse.julialang.org/t/annotating-only-a-few-points-with-statsplots/112635)

<div class="topic-metadata">

**Author:** [@dlshew19](https://discourse.julialang.org/u/dlshew19)\
**Replies:** 1\
**Last updated:** [April 7, 2024, 9:50am UTC](https://discourse.julialang.org/t/annotating-only-a-few-points-with-statsplots/112635 "2024-04-07T09:50:09Z")

</div>

Basically I’m trying label the a few of the markers with a name column of my dataframe. I have stats on the x and y axis and I want to label the player who’s it is but I don’t want to crowd the plot. This is how the data…

---

## [What are \`autodiff\_deferred\` and \`autodiff\_thunk\` for in Enzyme?](https://discourse.julialang.org/t/what-are-autodiff-deferred-and-autodiff-thunk-for-in-enzyme/112065)

<div class="topic-metadata">

**Author:** [@gdalle](https://discourse.julialang.org/u/gdalle)\
**Replies:** 23\
**Last updated:** [April 7, 2024, 5:37am UTC](https://discourse.julialang.org/t/what-are-autodiff-deferred-and-autodiff-thunk-for-in-enzyme/112065 "2024-04-07T05:37:00Z")

</div>

I think I understand the basic autodiff function (see this post) but it has three variants: autodiff\_deferred autodiff\_thunk (which seems broken on 1.11) autodiff\_deferred\_thunk Is there someone who can explain to me: …

---

## [\[pre-ANN\] CompressedBeliefMDPs.jl: Solve large POMDPs in POMDPs.jl!](https://discourse.julialang.org/t/pre-ann-compressedbeliefmdps-jl-solve-large-pomdps-in-pomdps-jl/112625)

<div class="topic-metadata">

**Author:** [@FlyingWorkshop](https://discourse.julialang.org/u/FlyingWorkshop)\
**Replies:** 0\
**Last updated:** [April 7, 2024, 4:28am UTC](https://discourse.julialang.org/t/pre-ann-compressedbeliefmdps-jl-solve-large-pomdps-in-pomdps-jl/112625 "2024-04-07T04:28:35Z")

</div>

https://github.com/JuliaPOMDP/CompressedBeliefMDPs.jl Hello everyone! I’m excited to announce CompressedBeliefMDPs.jl (docs on repo), an upcoming addition to the POMDPs.jl ecosystem. CompressedBeliefMDPs.jl provides a …

[Previous page](https://discourse.julialang.org/latest.md?page=438)

[Next page](https://discourse.julialang.org/latest.md?page=440)