# Latest

**URL:** https://discourse.julialang.org/latest.md?page=202

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

**Page:** 203

---

## [Access violation when using package JLD.jl](https://discourse.julialang.org/t/access-violation-when-using-package-jld-jl/126985)

<div class="topic-metadata">

**Author:** [@zyhsjtu](https://discourse.julialang.org/u/zyhsjtu)\
**Replies:** 5\
**Last updated:** [March 15, 2025, 2:56pm UTC](https://discourse.julialang.org/t/access-violation-when-using-package-jld-jl/126985 "2025-03-15T14:56:49Z")

</div>

Please submit a bug report with steps to reproduce this fault, and any error messages that follow (in their entirety). Thanks. Exception: EXCEPTION\_ACCESS\_VIOLATION at 0x2c1fc3ce3bf – unsafe\_load at .\\pointer.jl:153 \[in…

---

## [What packages for images, image pyramids and interpolation do you recommend?](https://discourse.julialang.org/t/what-packages-for-images-image-pyramids-and-interpolation-do-you-recommend/126950)

<div class="topic-metadata">

**Author:** [@user664303](https://discourse.julialang.org/u/user664303)\
**Replies:** 5\
**Last updated:** [March 15, 2025, 12:50pm UTC](https://discourse.julialang.org/t/what-packages-for-images-image-pyramids-and-interpolation-do-you-recommend/126950 "2025-03-15T12:50:39Z")

</div>

I’m planning to add photometric optimization (think Lucas-Kanade style model to image alignment, direct methods for visual odometry & SLAM, etc.) to my VisualGeometryOptimization package. I’d like to not re-invent the wh…

---

## [Occasional long delays in CUDA.jl](https://discourse.julialang.org/t/occasional-long-delays-in-cuda-jl/81545)

<div class="topic-metadata">

**Author:** [@jpdoane](https://discourse.julialang.org/u/jpdoane)\
**Replies:** 17\
**Last updated:** [March 15, 2025, 11:06am UTC](https://discourse.julialang.org/t/occasional-long-delays-in-cuda-jl/81545 "2025-03-15T11:06:00Z")

</div>

We have a real-time CUDA.jl application that must maintain a given time budget in order to keep up with a streaming input signal. Although the steady state performance meets timing, we occasional see fairly long delays t…

---

## [Updating a row in sparse cholesky factorisation using CHOLMOD](https://discourse.julialang.org/t/updating-a-row-in-sparse-cholesky-factorisation-using-cholmod/126683)

<div class="topic-metadata">

**Author:** [@wvanroos](https://discourse.julialang.org/u/wvanroos)\
**Replies:** 2\
**Last updated:** [March 15, 2025, 9:34am UTC](https://discourse.julialang.org/t/updating-a-row-in-sparse-cholesky-factorisation-using-cholmod/126683 "2025-03-15T09:34:52Z")

</div>

CHOLMOD allows the modification of a row of a sparse matrix and updates the factorisation, accordingly. There is a function ldlrowmod in Matlab that interfaces to rowadd and rowdel from CHOLMOD (SuiteSparse/CHOLMOD/MA…

---

## [Generic Functions Are Slow Here?](https://discourse.julialang.org/t/generic-functions-are-slow-here/126974)

<div class="topic-metadata">

**Author:** [@co1emi11er](https://discourse.julialang.org/u/co1emi11er)\
**Replies:** 3\
**Last updated:** [March 15, 2025, 5:26am UTC](https://discourse.julialang.org/t/generic-functions-are-slow-here/126974 "2025-03-15T05:26:18Z")

</div>

I write two functions that do the same thing, but one has allocations. All I change is the type from an abstract class to a concrete class. julia\> function baz((;h, t\_w, E, F\_y)::T) where T \<: AISCSteel.Shapes.IShapes.A…

---

## [VSCode Makie - Error loading webview: Error: Could not register service worker: InvalidStateError: Failed to register a ServiceWorker: The document is in an invalid state](https://discourse.julialang.org/t/vscode-makie-error-loading-webview-error-could-not-register-service-worker-invalidstateerror-failed-to-register-a-serviceworker-the-document-is-in-an-invalid-state/126972)

<div class="topic-metadata">

**Author:** [@jar1](https://discourse.julialang.org/u/jar1)\
**Replies:** 1\
**Last updated:** [March 15, 2025, 4:50am UTC](https://discourse.julialang.org/t/vscode-makie-error-loading-webview-error-could-not-register-service-worker-invalidstateerror-failed-to-register-a-serviceworker-the-document-is-in-an-invalid-state/126972 "2025-03-15T04:50:02Z")

</div>

In VSCode-Julia 1.127.2, when I try to view a Makie plot it says Error loading webview: Error: Could not register service worker: InvalidStateError: Failed to register a ServiceWorker: The document is in an invalid sta…

---

## [\[ANN\] HIENAA.jl - A pure Julia implementation of various FHE schemes](https://discourse.julialang.org/t/ann-hienaa-jl-a-pure-julia-implementation-of-various-fhe-schemes/126954)

<div class="topic-metadata">

**Author:** [@lukemin](https://discourse.julialang.org/u/lukemin)\
**Replies:** 2\
**Last updated:** [March 15, 2025, 3:00am UTC](https://discourse.julialang.org/t/ann-hienaa-jl-a-pure-julia-implementation-of-various-fhe-schemes/126954 "2025-03-15T03:00:23Z")

</div>

Github : Github Hello, everyone. I present HIENAA.jl (HE Implementation for Encrypted Numbers Arithmetic and Algorithms), which is a pure Julia implementation of a variety of FHE schemes, such as BGV/BFV/CKKS. For a qui…

---

## [Optimizing a function in optimal control problem](https://discourse.julialang.org/t/optimizing-a-function-in-optimal-control-problem/125483)

<div class="topic-metadata">

**Author:** [@yhchang](https://discourse.julialang.org/u/yhchang)\
**Replies:** 19\
**Last updated:** [March 15, 2025, 2:03am UTC](https://discourse.julialang.org/t/optimizing-a-function-in-optimal-control-problem/125483 "2025-03-15T02:03:34Z")

</div>

I’m trying to solve the following optimal control problem: minimize -\\int\_0^T v(t) dt, subject to \\frac{dv}{dt} = -\\frac{v}{\\tau} + f, v(0)=0 \\frac{de}{dt} = \\sigma - fv, e(0)=e\_0, e(t)\>=0 0\\leq f(t) \\leq f\_{max} is …

---

## [Reformulation perspectification technique: ideas embodied in a contrived example](https://discourse.julialang.org/t/reformulation-perspectification-technique-ideas-embodied-in-a-contrived-example/126804)

<div class="topic-metadata">

**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 1\
**Last updated:** [March 12, 2025, 1:36am UTC](https://discourse.julialang.org/t/reformulation-perspectification-technique-ideas-embodied-in-a-contrived-example/126804 "2025-03-12T01:36:59Z")

</div>

From Mosek’s cookbook we know: The feasibility system \\{ t \> 0, t(\\frac{x}{t})^2 \\le y \\} in \\mathbb{R}^3 can be coded as \[y + t, y - t, 2 \* x\] in JuMP.SecondOrderCone() In this tutorial we aim to solve the followin…

---

## [Symbolics.symplify must be invoked twice 2cos(x) - sin(2x)/sin(x)](https://discourse.julialang.org/t/symbolics-symplify-must-be-invoked-twice-2cos-x-sin-2x-sin-x/126944)

<div class="topic-metadata">

**Author:** [@fp4code](https://discourse.julialang.org/u/fp4code)\
**Replies:** 2\
**Last updated:** [March 15, 2025, 12:22am UTC](https://discourse.julialang.org/t/symbolics-symplify-must-be-invoked-twice-2cos-x-sin-2x-sin-x/126944 "2025-03-15T00:22:20Z")

</div>

Dear all, why do I have to invoke symplify twice? using Symbolics # v6.29.2, julia 1.11.4 @variables x v = 2cos(x) - sin(2x)/sin(x) va = simplify(v) # not simplified vb = simplify(va) # 0

---

## [Matrix (linear map function) exponential multiplied with vector in ExponentialUtilities.jl](https://discourse.julialang.org/t/matrix-linear-map-function-exponential-multiplied-with-vector-in-exponentialutilities-jl/126957)

<div class="topic-metadata">

**Author:** [@eveningsilverfox](https://discourse.julialang.org/u/eveningsilverfox)\
**Replies:** 10\
**Last updated:** [March 15, 2025, 12:04am UTC](https://discourse.julialang.org/t/matrix-linear-map-function-exponential-multiplied-with-vector-in-exponentialutilities-jl/126957 "2025-03-15T00:04:07Z")

</div>

I am trying to multiply the exponential of a matrix (available as a function which linearly maps the input vector to an output vector), to a given vector, using expv from ExponentialUtilities.jl using MKL using LinearAl…

---

## [Runtime dispatch for plan\_fft](https://discourse.julialang.org/t/runtime-dispatch-for-plan-fft/126958)

<div class="topic-metadata">

**Author:** [@henry2004y](https://discourse.julialang.org/u/henry2004y)\
**Replies:** 1\
**Last updated:** [March 14, 2025, 5:24pm UTC](https://discourse.julialang.org/t/runtime-dispatch-for-plan-fft/126958 "2025-03-14T17:24:10Z")

</div>

Hi, I am learning about JET.jl while optimizing a function that involves FFT. I happened to find that JET.jl detected a runtime dispatch for plan\_fft or plan\_fft!: using JET using FFTW julia\> @report\_opt plan\_fft!(zer…

---

## [Ipopt and non linear maximisation problem](https://discourse.julialang.org/t/ipopt-and-non-linear-maximisation-problem/126909)

<div class="topic-metadata">

**Author:** [@Ana1](https://discourse.julialang.org/u/Ana1)\
**Replies:** 6\
**Last updated:** [March 14, 2025, 4:57pm UTC](https://discourse.julialang.org/t/ipopt-and-non-linear-maximisation-problem/126909 "2025-03-14T16:57:37Z")

</div>

Hello everyone, I am working on a non linear dynamic optimization problem with ipopt solver on natural resources. I have a few questions and I hope some of you could help me. First I am wondering if I am using the righ…

---

## [Is Apple accelerate on Mac mini 4 mature enough for numerical simulation?](https://discourse.julialang.org/t/is-apple-accelerate-on-mac-mini-4-mature-enough-for-numerical-simulation/122890)

<div class="topic-metadata">

**Author:** [@photor](https://discourse.julialang.org/u/photor)\
**Replies:** 4\
**Last updated:** [March 14, 2025, 1:17pm UTC](https://discourse.julialang.org/t/is-apple-accelerate-on-mac-mini-4-mature-enough-for-numerical-simulation/122890 "2025-03-14T13:17:46Z")

</div>

I know that MATLAB has mature support for Apple accelerate. But how if we only use Python or Julia? Our numerical works are mainly dense linear algebra.

---

## [Reducing the number of allocations in a function](https://discourse.julialang.org/t/reducing-the-number-of-allocations-in-a-function/126906)

<div class="topic-metadata">

**Author:** [@andrea\_bertozzi](https://discourse.julialang.org/u/andrea_bertozzi)\
**Replies:** 14\
**Last updated:** [March 14, 2025, 12:30pm UTC](https://discourse.julialang.org/t/reducing-the-number-of-allocations-in-a-function/126906 "2025-03-14T12:30:39Z")

</div>

Hello, I have this function. When running benchmark, I get 519 allocations. Does anyone know how I can reduce those? Thank you! using LinearAlgebra struct Settings rho::Float64 g\_earth::Vector{Float64} cd…

---

## [Pkg performance on Windows Dev Drive](https://discourse.julialang.org/t/pkg-performance-on-windows-dev-drive/126948)

<div class="topic-metadata">

**Author:** [@visr](https://discourse.julialang.org/u/visr)\
**Replies:** 1\
**Last updated:** [March 14, 2025, 12:19pm UTC](https://discourse.julialang.org/t/pkg-performance-on-windows-dev-drive/126948 "2025-03-14T12:19:32Z")

</div>

I recently moved my Julia depot to a Dev Drive and am quite happy with the results, so I’m sharing my experience. This contrived benchmark sped up from 176 to 8 seconds: for i in 1:100\_000 open("file.txt", "w") do …

---

## [GeoStats.jl short-course at X Geoquanti](https://discourse.julialang.org/t/geostats-jl-short-course-at-x-geoquanti/126947)

<div class="topic-metadata">

**Author:** [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Replies:** 0\
**Last updated:** [March 14, 2025, 11:40am UTC](https://discourse.julialang.org/t/geostats-jl-short-course-at-x-geoquanti/126947 "2025-03-14T11:40:11Z")

</div>

If you are in Brazil, this is a great opportunity to learn geospatial data science with Julia. I am targeting a beginner audience with little Julia programming experience:

---

## [Right way to put code into a function?](https://discourse.julialang.org/t/right-way-to-put-code-into-a-function/126911)

<div class="topic-metadata">

**Author:** [@bpsomu](https://discourse.julialang.org/u/bpsomu)\
**Replies:** 6\
**Last updated:** [March 14, 2025, 10:14am UTC](https://discourse.julialang.org/t/right-way-to-put-code-into-a-function/126911 "2025-03-14T10:14:53Z")

</div>

I am writing a simulation code where there is an “input.toml” file which contains the initialization parameters (20 to 30 parameters) for the simulation. It works fine if I keep the code in the main where the variables s…

---

## [Quasi-static segmented tether model](https://discourse.julialang.org/t/quasi-static-segmented-tether-model/126810)

<div class="topic-metadata">

**Author:** [@Bart\_van\_de\_Lint](https://discourse.julialang.org/u/Bart_van_de_Lint)\
**Replies:** 10\
**Last updated:** [March 14, 2025, 9:47am UTC](https://discourse.julialang.org/t/quasi-static-segmented-tether-model/126810 "2025-03-14T09:47:10Z")

</div>

I want to make a quasi-static tether model of a segmented tether. This means that I want to use a nonlinear solver to find positions, such that the acceleration of the tether points is zero. For this I need to run a nonl…

---

## [How to modularize/package a large project | What kind of package/project directory structure works well?](https://discourse.julialang.org/t/how-to-modularize-package-a-large-project-what-kind-of-package-project-directory-structure-works-well/126819)

<div class="topic-metadata">

**Author:** [@world-peace](https://discourse.julialang.org/u/world-peace)\
**Replies:** 2\
**Last updated:** [March 14, 2025, 8:15am UTC](https://discourse.julialang.org/t/how-to-modularize-package-a-large-project-what-kind-of-package-project-directory-structure-works-well/126819 "2025-03-14T08:15:02Z")

</div>

I’m having some issues trying to find a directory structure for a large Julia project which works well. I have two requirements objectives. A structure which is convenient for deployment A structure which is convenien…

---

## [Building Julia master on Raspberry Pi](https://discourse.julialang.org/t/building-julia-master-on-raspberry-pi/10908)

<div class="topic-metadata">

**Author:** [@josefsachs](https://discourse.julialang.org/u/josefsachs)\
**Replies:** 10\
**Last updated:** [March 14, 2025, 4:37am UTC](https://discourse.julialang.org/t/building-julia-master-on-raspberry-pi/10908 "2025-03-14T04:37:08Z")

</div>

(I hope that Development is not an inappropriate category to use for this topic.) I had been building Julia master on Raspberry Pi from JuiliaCon 2016 until mid-February (https://github.com/JuliaLang/julia/issues/26122)…

---

## [Serializing many different arrays incrementally over time](https://discourse.julialang.org/t/serializing-many-different-arrays-incrementally-over-time/117777)

<div class="topic-metadata">

**Author:** [@tuckermcclure](https://discourse.julialang.org/u/tuckermcclure)\
**Replies:** 5\
**Last updated:** [March 14, 2025, 4:17am UTC](https://discourse.julialang.org/t/serializing-many-different-arrays-incrementally-over-time/117777 "2025-03-14T04:17:13Z")

</div>

I have a simulation that’s going to run for a long time, producing a lot of results, and I need those results to go do disk while the sim is running rather than all at once at the end (not enough RAM for all those result…

---

## [Makie plot specification?](https://discourse.julialang.org/t/makie-plot-specification/116979)

<div class="topic-metadata">

**Author:** [@tuckermcclure](https://discourse.julialang.org/u/tuckermcclure)\
**Replies:** 5\
**Last updated:** [March 14, 2025, 4:10am UTC](https://discourse.julialang.org/t/makie-plot-specification/116979 "2025-03-14T04:10:03Z")

</div>

I have a package, call it MyModels.jl, that needs to be light and fast, used mostly in backend tools that don’t want any visualization stuff in their dependencies. The package implements some mathematical models. In some …

---

## [Help with misbehaving ODE simulation](https://discourse.julialang.org/t/help-with-misbehaving-ode-simulation/126936)

<div class="topic-metadata">

**Author:** [@JonathanH](https://discourse.julialang.org/u/JonathanH)\
**Replies:** 1\
**Last updated:** [March 14, 2025, 12:43am UTC](https://discourse.julialang.org/t/help-with-misbehaving-ode-simulation/126936 "2025-03-14T00:43:24Z")

</div>

Hi all, I am having some issues with a set of ODEs I am simulating with DifferentialEquations.jl and am wondering if anyone can help. Basically, the code is simulating populations of bacteria and their viruses (phage) t…

---

## [Makie show image on surface](https://discourse.julialang.org/t/makie-show-image-on-surface/126893)

<div class="topic-metadata">

**Author:** [@grero](https://discourse.julialang.org/u/grero)\
**Replies:** 5\
**Last updated:** [March 14, 2025, 12:33am UTC](https://discourse.julialang.org/t/makie-show-image-on-surface/126893 "2025-03-14T00:33:59Z")

</div>

I’m trying to display images as posters around a 3D environment using GLMakie. For that purpose, I wrote the following code using Makie using GeometryBasics using FileIO struct Sprite{T\<:RGB,T2\<:Integer,T3\<:Point3, T4\<:…

---

## [Best way to prevent AD to differentiate through useless or zero gradient function](https://discourse.julialang.org/t/best-way-to-prevent-ad-to-differentiate-through-useless-or-zero-gradient-function/126927)

<div class="topic-metadata">

**Author:** [@FerreolS](https://discourse.julialang.org/u/FerreolS)\
**Replies:** 2\
**Last updated:** [March 13, 2025, 9:05pm UTC](https://discourse.julialang.org/t/best-way-to-prevent-ad-to-differentiate-through-useless-or-zero-gradient-function/126927 "2025-03-13T21:05:03Z")

</div>

I want to minimize a function of the type: x = \\textrm{argmin}\_x \\min\_a || f(x) a - y ||^2 as it is quadratic in a we know the optimum in a is a(x) = (f(x)^T f(x))^{-1} f(x)^T y so we minimize x = \\text{argmin}\_x …

---

## [Parallelism in NestedSamplers.jl \`Proposals\`](https://discourse.julialang.org/t/parallelism-in-nestedsamplers-jl-proposals/126933)

<div class="topic-metadata">

**Author:** [@Riccardo\_Buscicchio](https://discourse.julialang.org/u/Riccardo_Buscicchio)\
**Replies:** 0\
**Last updated:** [March 13, 2025, 8:00pm UTC](https://discourse.julialang.org/t/parallelism-in-nestedsamplers-jl-proposals/126933 "2025-03-13T20:00:30Z")

</div>

Hi all, I would be interested in extending the Proposals available in NestedSamplers.jl to allow for parallel evaluation of multiple proposals. Has anyone ever attempted to do so?

---

## [Best practice to handle type annotations](https://discourse.julialang.org/t/best-practice-to-handle-type-annotations/126925)

<div class="topic-metadata">

**Author:** [@dnldlg](https://discourse.julialang.org/u/dnldlg)\
**Replies:** 12\
**Last updated:** [March 13, 2025, 6:26pm UTC](https://discourse.julialang.org/t/best-practice-to-handle-type-annotations/126925 "2025-03-13T18:26:55Z")

</div>

From reading the Performance Tips in the Julia manual, I grasped that type declarations generally improve the performance and abstract types should be avoided. So lets say I have a function function func(x, n::Integer) …

---

## [Most efficient way to render large number of 2D objects in GLMakie in real-time?](https://discourse.julialang.org/t/most-efficient-way-to-render-large-number-of-2d-objects-in-glmakie-in-real-time/126924)

<div class="topic-metadata">

**Author:** [@mhinsch](https://discourse.julialang.org/u/mhinsch)\
**Replies:** 3\
**Last updated:** [March 13, 2025, 5:06pm UTC](https://discourse.julialang.org/t/most-efficient-way-to-render-large-number-of-2d-objects-in-glmakie-in-real-time/126924 "2025-03-13T17:06:27Z")

</div>

I’m implementing a real-time visualisation of a simulation that consists of drawing up to tens of thousands of objects on the screen where objects are represented by simple geometric shapes (or combinations thereof). Pos…

---

## [Sparse dot product: return 1x1 SparseArray, not Float64](https://discourse.julialang.org/t/sparse-dot-product-return-1x1-sparsearray-not-float64/126873)

<div class="topic-metadata">

**Author:** [@luke-kiernan](https://discourse.julialang.org/u/luke-kiernan)\
**Replies:** 6\
**Last updated:** [March 13, 2025, 4:46pm UTC](https://discourse.julialang.org/t/sparse-dot-product-return-1x1-sparsearray-not-float64/126873 "2025-03-13T16:46:49Z")

</div>

I have an array J with a known fixed sparsity structure–it’s the Jacobian of some function f(x) from R^n to R^n, but the sparsity structure doesn’t depend on x. I’m repeatedly calculating M = c\_1 I+c\_2 J(x\_1)' J(x\_2), fo…

[Previous page](https://discourse.julialang.org/latest.md?page=201)

[Next page](https://discourse.julialang.org/latest.md?page=203)