# Latest

**URL:** https://discourse.julialang.org/latest.md?page=338

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

**Page:** 339

---

## [Integral of some ModelingToolkitQuantity](https://discourse.julialang.org/t/integral-of-some-modelingtoolkitquantity/118398)

<div class="topic-metadata">

**Author:** [@cstjean](https://discourse.julialang.org/u/cstjean)\
**Replies:** 1\
**Last updated:** [August 20, 2024, 3:05am UTC](https://discourse.julialang.org/t/integral-of-some-modelingtoolkitquantity/118398 "2024-08-20T03:05:57Z")

</div>

I’m interested in computing the definite integral of some variable X, defined in ModelingToolkit. For sake of example, consider something like: X ~ Y \* Z D(Y) ~ Y \* 2 D(Z) ~ Z / t (in particular, X is an “observed” in …

---

## [How to link a JuMP model and a general algorithm together?](https://discourse.julialang.org/t/how-to-link-a-jump-model-and-a-general-algorithm-together/118356)

<div class="topic-metadata">

**Author:** [@WuSiren](https://discourse.julialang.org/u/WuSiren)\
**Replies:** 4\
**Last updated:** [August 20, 2024, 2:59am UTC](https://discourse.julialang.org/t/how-to-link-a-jump-model-and-a-general-algorithm-together/118356 "2024-08-20T02:59:51Z")

</div>

Suppose there is a general algorithm for some kind of optimization problem in a standard form, and then there is an instance of this kind of problem which is however not written in the standard form. Both of the algorit…

---

## [Erf function is not supported](https://discourse.julialang.org/t/erf-function-is-not-supported/118251)

<div class="topic-metadata">

**Author:** [@Simran\_Lakhani](https://discourse.julialang.org/u/Simran_Lakhani)\
**Replies:** 6\
**Last updated:** [August 20, 2024, 1:11am UTC](https://discourse.julialang.org/t/erf-function-is-not-supported/118251 "2024-08-20T01:11:17Z")

</div>

I have a MINLP that involves error cdf and pdf of normal distribution in the objective function. I used erf from SpecialFunctions it is not supported. I also tried approximations of erf, even that does not work. I used K…

---

## [Is there a way to delete old solutions from a JuMP model?](https://discourse.julialang.org/t/is-there-a-way-to-delete-old-solutions-from-a-jump-model/118394)

<div class="topic-metadata">

**Author:** [@dlcole3](https://discourse.julialang.org/u/dlcole3)\
**Replies:** 1\
**Last updated:** [August 20, 2024, 1:05am UTC](https://discourse.julialang.org/t/is-there-a-way-to-delete-old-solutions-from-a-jump-model/118394 "2024-08-20T01:05:01Z")

</div>

I am working on a problem where I am solving a model and then trying to get an additional feasible solution for the model by reseting the objective function (there are more details behind this, but the general idea will …

---

## [Problems with sequential update with @turbo](https://discourse.julialang.org/t/problems-with-sequential-update-with-turbo/118397)

<div class="topic-metadata">

**Author:** [@2xu2](https://discourse.julialang.org/u/2xu2)\
**Replies:** 0\
**Last updated:** [August 20, 2024, 12:42am UTC](https://discourse.julialang.org/t/problems-with-sequential-update-with-turbo/118397 "2024-08-20T00:42:53Z")

</div>

I have the following minimal working example that contains two weird behaviors of @turbo with sequential update: using LoopVectorization # Incorrect usage of @turbo function wrong\_example(n) x = 0.0 y = zeros(…

---

## [LibPQ on the Raspberry PI](https://discourse.julialang.org/t/libpq-on-the-raspberry-pi/118282)

<div class="topic-metadata">

**Author:** [@Jake](https://discourse.julialang.org/u/Jake)\
**Replies:** 1\
**Last updated:** [August 20, 2024, 12:17am UTC](https://discourse.julialang.org/t/libpq-on-the-raspberry-pi/118282 "2024-08-20T00:17:44Z")

</div>

I have LibPQ working on a Windows machine. I am now trying to get it to work on a Raspberry PI 4. The RPI has 64 bit bookworm installed as Raspberry PI OS. It is up to date. I installed Postgresql using the installat…

---

## [\`solve(::OptimizationProblem)\`: ub argument not quite respected](https://discourse.julialang.org/t/solve-optimizationproblem-ub-argument-not-quite-respected/118393)

<div class="topic-metadata">

**Author:** [@cstjean](https://discourse.julialang.org/u/cstjean)\
**Replies:** 1\
**Last updated:** [August 20, 2024, 12:09am UTC](https://discourse.julialang.org/t/solve-optimizationproblem-ub-argument-not-quite-respected/118393 "2024-08-20T00:09:33Z")

</div>

I have a fairly benign Optimization.OptimizationProblem (over an MTK problem). Passing lb, ub clearly works, but I encountered a case today where the output was retcode: Success u: 3×2 Matrix{Float64}: 10.0 15.0 18…

---

## [Symbolics vs Reduce?](https://discourse.julialang.org/t/symbolics-vs-reduce/118322)

<div class="topic-metadata">

**Author:** [@brombo](https://discourse.julialang.org/u/brombo)\
**Replies:** 11\
**Last updated:** [August 19, 2024, 10:53pm UTC](https://discourse.julialang.org/t/symbolics-vs-reduce/118322 "2024-08-19T22:53:17Z")

</div>

I have been using Symbolics in Julia and the only other symbolic algebra package I have used is sympy (from python). My question is does Julia Symbolics/SymbolicUtils use Reduce (I do see there is a Julia interface for …

---

## [Optimizing function to evaluate elementary symmetric polynomials](https://discourse.julialang.org/t/optimizing-function-to-evaluate-elementary-symmetric-polynomials/118321)

<div class="topic-metadata">

**Author:** [@Gattu\_Mytraya](https://discourse.julialang.org/u/Gattu_Mytraya)\
**Replies:** 2\
**Last updated:** [August 19, 2024, 9:40pm UTC](https://discourse.julialang.org/t/optimizing-function-to-evaluate-elementary-symmetric-polynomials/118321 "2024-08-19T21:40:50Z")

</div>

Hi, I am working on optimizing the following function: @inbounds function get\_symmetric\_polynomials!(dest::Matrix{Complex{MultiFloat{Float64, 2}}}, roots::Matrix{Complex{MultiFloat{Float64, 2}}}, b::Int64) if b ==…

---

## [The new \`invmod(n, T)\` function and even arguments](https://discourse.julialang.org/t/the-new-invmod-n-t-function-and-even-arguments/118377)

<div class="topic-metadata">

**Author:** [@Ken\_Williams](https://discourse.julialang.org/u/Ken_Williams)\
**Replies:** 2\
**Last updated:** [August 19, 2024, 8:45pm UTC](https://discourse.julialang.org/t/the-new-invmod-n-t-function-and-even-arguments/118377 "2024-08-19T20:45:59Z")

</div>

I was reading about new features in Julia 1.11 and happened upon this new invmod capability: invmod(n::BitInteger): efficient native modular inverses by StefanKarpinski · Pull Request #52180 · JuliaLang/julia · GitHub . …

---

## [Performance of loops](https://discourse.julialang.org/t/performance-of-loops/118273)

<div class="topic-metadata">

**Author:** [@Matthijs\_1971](https://discourse.julialang.org/u/Matthijs_1971)\
**Replies:** 30\
**Last updated:** [August 19, 2024, 8:20pm UTC](https://discourse.julialang.org/t/performance-of-loops/118273 "2024-08-19T20:20:45Z")

</div>

Julia has several ways to define loops or repeat code, each with advantages and disadvantages. I am looking at the performance of some also inspired by previous posts on this forum. #!/usr/bin/env julia # https://disco…

---

## [\[ANN\] Introducing the JuliaHealth Blog!](https://discourse.julialang.org/t/ann-introducing-the-juliahealth-blog/118388)

<div class="topic-metadata">

**Author:** [@TheCedarPrince](https://discourse.julialang.org/u/TheCedarPrince)\
**Replies:** 0\
**Last updated:** [August 19, 2024, 8:19pm UTC](https://discourse.julialang.org/t/ann-introducing-the-juliahealth-blog/118388 "2024-08-19T20:19:32Z")

</div>

Hi folks! :wave: Have an announcement to make: We have a public JuliaHealth Blog now! There is not much on the blog at this time beyond us just now having the dedicated space. It is built using quarto and each blog pos…

---

## [Can you overload if-else-blocks? (for bounded model checking)](https://discourse.julialang.org/t/can-you-overload-if-else-blocks-for-bounded-model-checking/118364)

<div class="topic-metadata">

**Author:** [@phK3](https://discourse.julialang.org/u/phK3)\
**Replies:** 2\
**Last updated:** [August 19, 2024, 7:19pm UTC](https://discourse.julialang.org/t/can-you-overload-if-else-blocks-for-bounded-model-checking/118364 "2024-08-19T19:19:30Z")

</div>

Recently we had a really hard-to-debug error in our code, so I was thinking about doing formal verification - especially bounded model checking - for julia. I thought that translating a piece of Julia code to an equival…

---

## [Best way to calculate B' \* A \* B](https://discourse.julialang.org/t/best-way-to-calculate-b-a-b/118382)

<div class="topic-metadata">

**Author:** [@marcsgil](https://discourse.julialang.org/u/marcsgil)\
**Replies:** 1\
**Last updated:** [August 19, 2024, 7:09pm UTC](https://discourse.julialang.org/t/best-way-to-calculate-b-a-b/118382 "2024-08-19T19:09:22Z")

</div>

I’d like to calculate B' \* A \* B, where A is Hermitian, without allocating intermediary results. Note that B will be, in general, a rectangular matrix. I’m currently using Tullio to do the calculation, but I was wonderin…

---

## [Will AI make programming languages obsolete?](https://discourse.julialang.org/t/will-ai-make-programming-languages-obsolete/118276)

<div class="topic-metadata">

**Author:** [@yvikhlya](https://discourse.julialang.org/u/yvikhlya)\
**Replies:** 4\
**Last updated:** [August 19, 2024, 6:53pm UTC](https://discourse.julialang.org/t/will-ai-make-programming-languages-obsolete/118276 "2024-08-19T18:53:11Z")

</div>

The topic is a bit provocative, but I am interested to hear opinion of people who understand how programing languages and compilers work. According to some resources dedicated to AI discussion, many software developers a…

---

## [What is the Pkg.jl package dependency resolver (solver algorithm)?](https://discourse.julialang.org/t/what-is-the-pkg-jl-package-dependency-resolver-solver-algorithm/77821)

<div class="topic-metadata">

**Author:** [@patrsc](https://discourse.julialang.org/u/patrsc)\
**Replies:** 10\
**Last updated:** [August 19, 2024, 5:35pm UTC](https://discourse.julialang.org/t/what-is-the-pkg-jl-package-dependency-resolver-solver-algorithm/77821 "2024-08-19T17:35:53Z")

</div>

According to its source code, Pkg.jl uses a dependency resolving algorithm called MaxSum to resolve the package dependency graph. However, I was not able to find any documentation about this algorithm, or any concrete re…

---

## [StatsBase.wsum doesn't work for iterators](https://discourse.julialang.org/t/statsbase-wsum-doesnt-work-for-iterators/118289)

<div class="topic-metadata">

**Author:** [@freeman](https://discourse.julialang.org/u/freeman)\
**Replies:** 1\
**Last updated:** [August 19, 2024, 4:56pm UTC](https://discourse.julialang.org/t/statsbase-wsum-doesnt-work-for-iterators/118289 "2024-08-19T16:56:28Z")

</div>

StatsBase.wsum (and others) don’t work on iterators. Is there a fundamental reason for this? And speaking of which, the docstring shows wsum(v, w::AbstractVector, \[dim\]) but in reality all methods are v::AbstractArray. …

---

## [Type issue in for loop over items in struct field](https://discourse.julialang.org/t/type-issue-in-for-loop-over-items-in-struct-field/118268)

<div class="topic-metadata">

**Author:** [@JADekker](https://discourse.julialang.org/u/JADekker)\
**Replies:** 19\
**Last updated:** [August 19, 2024, 4:45pm UTC](https://discourse.julialang.org/t/type-issue-in-for-loop-over-items-in-struct-field/118268 "2024-08-19T16:45:50Z")

</div>

Hi, I’m encountering what I think is a type(-stability?) issue in the below MWE; is there a way in which I can resolve the problem within fun\_test? (I’d rather not change the structure of Aux, BasisOperation and AOperati…

---

## [Activating and adding the packages in new folder only include the project and Manifest toml files](https://discourse.julialang.org/t/activating-and-adding-the-packages-in-new-folder-only-include-the-project-and-manifest-toml-files/118374)

<div class="topic-metadata">

**Author:** [@fasihullahsaleem](https://discourse.julialang.org/u/fasihullahsaleem)\
**Replies:** 2\
**Last updated:** [August 19, 2024, 3:44pm UTC](https://discourse.julialang.org/t/activating-and-adding-the-packages-in-new-folder-only-include-the-project-and-manifest-toml-files/118374 "2024-08-19T15:44:38Z")

</div>

Hello, so I want to ask some questions as I didn’t find answer to these. When I try to remove the Package that I installed before, it says it removed it. but when I go to the folder of packages that package exists in i…

---

## [Genie/Stipple: hot to use Plots.jl?](https://discourse.julialang.org/t/genie-stipple-hot-to-use-plots-jl/118372)

<div class="topic-metadata">

**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 1\
**Last updated:** [August 19, 2024, 2:03pm UTC](https://discourse.julialang.org/t/genie-stipple-hot-to-use-plots-jl/118372 "2024-08-19T14:03:46Z")

</div>

I am trying to run the example on the documentation: App.jlmodule App using GenieFramework, PlotlyBase @genietools function gen\_numbers(N::Int) return rand(N) end function calc\_mean(x::Vector{Float64}) return…

---

## [Counting Exchanges To Order Array with Repeats](https://discourse.julialang.org/t/counting-exchanges-to-order-array-with-repeats/118342)

<div class="topic-metadata">

**Author:** [@brombo](https://discourse.julialang.org/u/brombo)\
**Replies:** 9\
**Last updated:** [August 19, 2024, 1:57pm UTC](https://discourse.julialang.org/t/counting-exchanges-to-order-array-with-repeats/118342 "2024-08-19T13:57:56Z")

</div>

I am asking this question to avoid reinventing the wheel (also because I am lazy). I have to arrays of integers in normal order with no repeats within each array. Then I generate an array by concatenation the two array…

---

## [Determining lower bound of compat statement](https://discourse.julialang.org/t/determining-lower-bound-of-compat-statement/117248)

<div class="topic-metadata">

**Author:** [@bclyons12](https://discourse.julialang.org/u/bclyons12)\
**Replies:** 1\
**Last updated:** [August 19, 2024, 1:45pm UTC](https://discourse.julialang.org/t/determining-lower-bound-of-compat-statement/117248 "2024-08-19T13:45:19Z")

</div>

Is there a way to test the lower bound compatibility of a package systematically, say by doing a binary search to find the lowest version for which tests pass? When adding a new compat entry to a Project.toml, CompatHelp…

---

## [Documentation to pdf](https://discourse.julialang.org/t/documentation-to-pdf/118359)

<div class="topic-metadata">

**Author:** [@jackmarry](https://discourse.julialang.org/u/jackmarry)\
**Replies:** 3\
**Last updated:** [August 19, 2024, 1:36pm UTC](https://discourse.julialang.org/t/documentation-to-pdf/118359 "2024-08-19T13:36:31Z")

</div>

I want to download the documentation of the Julia package in PDF format directly and in one go. How can I do it?

---

## [ModelingToolkit fails to pre-compile](https://discourse.julialang.org/t/modelingtoolkit-fails-to-pre-compile/118361)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 3\
**Last updated:** [August 19, 2024, 11:10am UTC](https://discourse.julialang.org/t/modelingtoolkit-fails-to-pre-compile/118361 "2024-08-19T11:10:36Z")

</div>

Since this morning I cannot freshly install ModellingToolkit any longer, neither the latest nor older versions. I get this error: The following 1 direct dependency failed to precompile: ModelingToolkit \[961ee093-0014-5…

---

## [Error in Images (FFTW.dct)](https://discourse.julialang.org/t/error-in-images-fftw-dct/118344)

<div class="topic-metadata">

**Author:** [@AbdelazimHussien](https://discourse.julialang.org/u/AbdelazimHussien)\
**Replies:** 9\
**Last updated:** [August 19, 2024, 9:14am UTC](https://discourse.julialang.org/t/error-in-images-fftw-dct/118344 "2024-08-19T09:14:16Z")

</div>

Hello I have the following code using FFTW using TestImages, ImageView, Random using Plots module Codec1 function blockdct6(img::Matrix{Float32}) y, x = size(img) outx = div(x, 8) outy = d…

---

## [Jupyter Notebook nbconvert does not fail on julia error](https://discourse.julialang.org/t/jupyter-notebook-nbconvert-does-not-fail-on-julia-error/118168)

<div class="topic-metadata">

**Author:** [@Simon\_Exner](https://discourse.julialang.org/u/Simon_Exner)\
**Replies:** 3\
**Last updated:** [August 19, 2024, 9:04am UTC](https://discourse.julialang.org/t/jupyter-notebook-nbconvert-does-not-fail-on-julia-error/118168 "2024-08-19T09:04:59Z")

</div>

Hi, I have trouble with the following commands: jupyter nbconvert --ExecutePreprocessor.kernel\_name="julia-1.10" --to notebook --inplace --execute ${{ env.FILE }} jupyter nbconvert --to script ${{ env.FILE }} jupyter n…

---

## [Static structs with constant field](https://discourse.julialang.org/t/static-structs-with-constant-field/48009)

<div class="topic-metadata">

**Author:** [@Impressium](https://discourse.julialang.org/u/Impressium)\
**Replies:** 6\
**Last updated:** [August 19, 2024, 8:35am UTC](https://discourse.julialang.org/t/static-structs-with-constant-field/48009 "2024-08-19T08:35:30Z")

</div>

Hey guys, It’s there a way to declare a constant struct. const struct A a = 1 b = "value" end println(A.b) Thy for your time

---

## [Plots on Windows: failed to precompile FFMPEG](https://discourse.julialang.org/t/plots-on-windows-failed-to-precompile-ffmpeg/118360)

<div class="topic-metadata">

**Author:** [@VivMendes](https://discourse.julialang.org/u/VivMendes)\
**Replies:** 7\
**Last updated:** [August 18, 2024, 5:41pm UTC](https://discourse.julialang.org/t/plots-on-windows-failed-to-precompile-ffmpeg/118360 "2024-08-18T17:41:56Z")

</div>

Is there any news on this problem? I have the same issue on a Windows 10 machine, Julia 1.9.3, Plots v1.39.0. The error I get is the following: ERROR: LoadError: InitError: could not load library "C:\\Users\\viv\\.julia\\a…

---

## [\[ANN\] Solution of linear finite element problems with domain decomposition](https://discourse.julialang.org/t/ann-solution-of-linear-finite-element-problems-with-domain-decomposition/118346)

<div class="topic-metadata">

**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 0\
**Last updated:** [August 18, 2024, 10:53pm UTC](https://discourse.julialang.org/t/ann-solution-of-linear-finite-element-problems-with-domain-decomposition/118346 "2024-08-18T22:53:00Z")

</div>

GitHub - PetrKryslUCSD/FinEtoolsDDMethods.jl has now reached the stage when it becomes possible to use it, either in serial fashion or with MPI parallelization. Feedback and suggestions will be appreciated.

---

## [BVP Shooting method with free parameters](https://discourse.julialang.org/t/bvp-shooting-method-with-free-parameters/117955)

<div class="topic-metadata">

**Author:** [@psillano](https://discourse.julialang.org/u/psillano)\
**Replies:** 13\
**Last updated:** [August 19, 2024, 2:55am UTC](https://discourse.julialang.org/t/bvp-shooting-method-with-free-parameters/117955 "2024-08-19T02:55:29Z")

</div>

Hey, Im trying to solve a Boundary Value Problems with DifferentialEquations.jl. My system of equations is composed by 4 equations of which I know 3 initial conditions. One initial condition u\_0 and 2 free parameters (o…

[Previous page](https://discourse.julialang.org/latest.md?page=337)

[Next page](https://discourse.julialang.org/latest.md?page=339)