# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=9

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

**Page:** 10

---

## [New package: NewtonCQK.jl](https://discourse.julialang.org/t/new-package-newtoncqk-jl/136254)

<div class="topic-metadata">

**Author:** [@pjssilva](https://discourse.julialang.org/u/pjssilva)\
**Replies:** 0\
**Last updated:** [March 18, 2026, 1:49pm UTC](https://discourse.julialang.org/t/new-package-newtoncqk-jl/136254 "2026-03-18T13:49:34Z")

</div>

Hi, I would like to announce a new Julia package named NewtonCQK.jl. It implements a semismooth Newton method to solve the Continuous Quadratick Knapsack problem \\min\_x \\frac{1}{2}x^tDx - a^tx \\quad \\text{s.t.} \\quad …

---

## [Do JuMP Variable ensure contiguous memory to Gurobi?](https://discourse.julialang.org/t/do-jump-variable-ensure-contiguous-memory-to-gurobi/136177)

<div class="topic-metadata">

**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 7\
**Last updated:** [March 18, 2026, 6:17am UTC](https://discourse.julialang.org/t/do-jump-variable-ensure-contiguous-memory-to-gurobi/136177 "2026-03-18T06:17:38Z")

</div>

The motivation is that I notices Gurobi exposes the 3 APIs. GRBsetdblattrelement GRBsetdblattrarray GRBsetdblattrlist Allegedly, using GRBsetdblattrarray should be the fastest (than using the list counterpart, than us…

---

## [ODE stepping with discrete input](https://discourse.julialang.org/t/ode-stepping-with-discrete-input/136104)

<div class="topic-metadata">

**Author:** [@ohmsweetohm1](https://discourse.julialang.org/u/ohmsweetohm1)\
**Replies:** 5\
**Last updated:** [March 17, 2026, 10:32pm UTC](https://discourse.julialang.org/t/ode-stepping-with-discrete-input/136104 "2026-03-17T22:32:03Z")

</div>

Hi I am using DiffEq with manual solver stepping and piecewise constant inputs. This image shows an integrator \\frac{dx}{dt} = u with a switching input 0 or 1. Hence the state should never decrease, but it does. O…

---

## [MathOptInterface and MultiObjectiveAlgorithms functionality to implement a multiobjective algorithm (AUGMECON)](https://discourse.julialang.org/t/mathoptinterface-and-multiobjectivealgorithms-functionality-to-implement-a-multiobjective-algorithm-augmecon/136243)

<div class="topic-metadata">

**Author:** [@Josa9321](https://discourse.julialang.org/u/Josa9321)\
**Replies:** 1\
**Last updated:** [March 17, 2026, 8:39pm UTC](https://discourse.julialang.org/t/mathoptinterface-and-multiobjectivealgorithms-functionality-to-implement-a-multiobjective-algorithm-augmecon/136243 "2026-03-17T20:39:48Z")

</div>

Hi. I’m currently working on adapting an AUGMECON implementation in JuMP to use the MultiObjectiveAlgorithms module as its base. As part of this process, I’m adjusting AUGMECON to follow the MOA structure and implementi…

---

## [DiffEqGPU - error calling solve() for SDE driven by 2 correlated Brownians](https://discourse.julialang.org/t/diffeqgpu-error-calling-solve-for-sde-driven-by-2-correlated-brownians/136118)

<div class="topic-metadata">

**Author:** [@sob](https://discourse.julialang.org/u/sob)\
**Replies:** 7\
**Last updated:** [March 17, 2026, 12:39pm UTC](https://discourse.julialang.org/t/diffeqgpu-error-calling-solve-for-sde-driven-by-2-correlated-brownians/136118 "2026-03-17T12:39:03Z")

</div>

Julia version: latest stable 1.12.5 on Linux, up to date on packages I have a 2D SDE driven by 2 Brownians with correlation ρ, and I’m trying to solve on the GPU using SciML. I should note that I am separately able to M…

---

## [OptimizationState in Optim.jl does not have expected fields](https://discourse.julialang.org/t/optimizationstate-in-optim-jl-does-not-have-expected-fields/136212)

<div class="topic-metadata">

**Author:** [@pjssilva](https://discourse.julialang.org/u/pjssilva)\
**Replies:** 3\
**Last updated:** [March 16, 2026, 11:33pm UTC](https://discourse.julialang.org/t/optimizationstate-in-optim-jl-does-not-have-expected-fields/136212 "2026-03-16T23:33:03Z")

</div>

Hello. I am trying to use the callback functionality Optim.jl’s solvers (CG and LBFGS). However, the state passed to the callback function does not seem to have the expected fields. In fact, the state only has the fields…

---

## [Analysing TRDP-Packets](https://discourse.julialang.org/t/analysing-trdp-packets/136216)

<div class="topic-metadata">

**Author:** [@ellocco](https://discourse.julialang.org/u/ellocco)\
**Replies:** 0\
**Last updated:** [March 16, 2026, 9:08am UTC](https://discourse.julialang.org/t/analysing-trdp-packets/136216 "2026-03-16T09:08:23Z")

</div>

To listen TRDP-data-packages one can work with the domain software Wireshark and if you copy the library trdp\_spy.dll / trdp\_spy.sh into the base directory of this SW you can analyse TRDP-communication. Now I wonder if…

---

## [How to display the differential equations from Catalyst.jl?](https://discourse.julialang.org/t/how-to-display-the-differential-equations-from-catalyst-jl/136203)

<div class="topic-metadata">

**Author:** [@tp2750](https://discourse.julialang.org/u/tp2750)\
**Replies:** 1\
**Last updated:** [March 14, 2026, 5:41pm UTC](https://discourse.julialang.org/t/how-to-display-the-differential-equations-from-catalyst-jl/136203 "2026-03-14T17:41:59Z")

</div>

I can not get this example in Introduction to Catalyst · Catalyst.jl to work. It gives the following error: julia\> odesys = convert(ODESystem, rn) ERROR: MethodError: Cannot \`convert\` an object of type ReactionSystem{C…

---

## [MTK & linearization with analysis points](https://discourse.julialang.org/t/mtk-linearization-with-analysis-points/136165)

<div class="topic-metadata">

**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 9\
**Last updated:** [March 14, 2026, 11:21am UTC](https://discourse.julialang.org/t/mtk-linearization-with-analysis-points/136165 "2026-03-14T11:21:08Z")

</div>

I am playing around with MTK v11 (v11.14) and trying to understand connectors, components + signals. My code now work, and I can specify signals. I use a chemical reactor (liquid phase) as an example, where the temperatu…

---

## [How to get a numeric value for equations of an MTK system with given numeric inputs](https://discourse.julialang.org/t/how-to-get-a-numeric-value-for-equations-of-an-mtk-system-with-given-numeric-inputs/136191)

<div class="topic-metadata">

**Author:** [@mark.garnett](https://discourse.julialang.org/u/mark.garnett)\
**Replies:** 2\
**Last updated:** [March 13, 2026, 8:05pm UTC](https://discourse.julialang.org/t/how-to-get-a-numeric-value-for-equations-of-an-mtk-system-with-given-numeric-inputs/136191 "2026-03-13T20:05:34Z")

</div>

Hi all, new to Julia here. I have created a decently sized MTK system out of connected components. (Thermal fluid system, components connected via ports. That part is several hundred lines of code so I don’t want to post…

---

## [How to automatically choose legend location in Makie?](https://discourse.julialang.org/t/how-to-automatically-choose-legend-location-in-makie/136105)

<div class="topic-metadata">

**Author:** [@Abhro](https://discourse.julialang.org/u/Abhro)\
**Replies:** 5\
**Last updated:** [March 13, 2026, 1:23pm UTC](https://discourse.julialang.org/t/how-to-automatically-choose-legend-location-in-makie/136105 "2026-03-13T13:23:58Z")

</div>

When I plot a series with Makie and label it, how do I get axislegend to automatically pick the empty part of the axis to place the legend in to? Example: (don’t worry about the data source lol) Best explored in a Julia…

---

## [Mutation attempt in \`ContinuousCallback\` when solving \`SDEProblem{StaticArraysCore.SVector{2, Float64}}\`](https://discourse.julialang.org/t/mutation-attempt-in-continuouscallback-when-solving-sdeproblem-staticarrayscore-svector-2-float64/136168)

<div class="topic-metadata">

**Author:** [@NoFishLikeIan](https://discourse.julialang.org/u/NoFishLikeIan)\
**Replies:** 1\
**Last updated:** [March 13, 2026, 11:37am UTC](https://discourse.julialang.org/t/mutation-attempt-in-continuouscallback-when-solving-sdeproblem-staticarrayscore-svector-2-float64/136168 "2026-03-13T11:37:29Z")

</div>

I have an SDE where the drift function f is defined out-of-place and the state is a StaticArrays.SVector. I need to terminate! the integration using a ContinuousCallback. This raises an error, as the StochasticDiffEq pac…

---

## [Should ownership of XLSX.jl transfer to JuliaData?](https://discourse.julialang.org/t/should-ownership-of-xlsx-jl-transfer-to-juliadata/135023)

<div class="topic-metadata">

**Author:** [@TimG](https://discourse.julialang.org/u/TimG)\
**Replies:** 13\
**Last updated:** [March 13, 2026, 12:29am UTC](https://discourse.julialang.org/t/should-ownership-of-xlsx-jl-transfer-to-juliadata/135023 "2026-03-13T00:29:13Z")

</div>

XLSX.jl seems to be a well used package. It has 298 stars on GitHub, for example. Unfortunately, the package owner seems no longer to be active, and so active maintenance of the package has more or less stopped. Excel i…

---

## [Position of the Moon (topocentric) using Astrometry.jl (SOFA/ERFA) routines](https://discourse.julialang.org/t/position-of-the-moon-topocentric-using-astrometry-jl-sofa-erfa-routines/135611)

<div class="topic-metadata">

**Author:** [@tamasgal](https://discourse.julialang.org/u/tamasgal)\
**Replies:** 15\
**Last updated:** [March 12, 2026, 5:36pm UTC](https://discourse.julialang.org/t/position-of-the-moon-topocentric-using-astrometry-jl-sofa-erfa-routines/135611 "2026-03-12T17:36:34Z")

</div>

OK I finally ask for help here because I am losing my head :face\_with\_spiral\_eyes: I want to calculate the Moon coordinates in an equatorial coordinate system for an observer on Earth at a given time using Astrometry.jl…

---

## [Bridging MTK and JuMP](https://discourse.julialang.org/t/bridging-mtk-and-jump/136148)

<div class="topic-metadata">

**Author:** [@langestefan](https://discourse.julialang.org/u/langestefan)\
**Replies:** 5\
**Last updated:** [March 12, 2026, 2:19pm UTC](https://discourse.julialang.org/t/bridging-mtk-and-jump/136148 "2026-03-12T14:19:53Z")

</div>

I am doing some basic thermal modelling in MTK, and I want to use the resulting discretized dynamics in a JuMP model. I came up with the following PoC: using Pkg Pkg.activate(".") import ModelingToolkit as MTK using J…

---

## [Best Julia Package for Neural Networks](https://discourse.julialang.org/t/best-julia-package-for-neural-networks/45358)

<div class="topic-metadata">

**Author:** [@Jojo\_Dad](https://discourse.julialang.org/u/Jojo_Dad)\
**Replies:** 13\
**Last updated:** [March 12, 2026, 10:46am UTC](https://discourse.julialang.org/t/best-julia-package-for-neural-networks/45358 "2026-03-12T10:46:44Z")

</div>

What is currently the best machine learning package in Julia? First, in terms of ease of use for students. Second, in terms of capability & performance for experts?

---

## [Incorporating Splines and Offset in MixedModels.jl](https://discourse.julialang.org/t/incorporating-splines-and-offset-in-mixedmodels-jl/136025)

<div class="topic-metadata">

**Author:** [@imantha](https://discourse.julialang.org/u/imantha)\
**Replies:** 3\
**Last updated:** [March 12, 2026, 4:23am UTC](https://discourse.julialang.org/t/incorporating-splines-and-offset-in-mixedmodels-jl/136025 "2026-03-12T04:23:57Z")

</div>

Hi, I am working on project that required doing multilevel models and the dataset is quite large (7 million rows). My current implementation is in R but takes quite a bit of time using glmmTMB package. So, I was wonderi…

---

## [Evaluating arbitrary symbolic expression on ODE solution](https://discourse.julialang.org/t/evaluating-arbitrary-symbolic-expression-on-ode-solution/136130)

<div class="topic-metadata">

**Author:** [@cstjean](https://discourse.julialang.org/u/cstjean)\
**Replies:** 2\
**Last updated:** [March 11, 2026, 9:23am UTC](https://discourse.julialang.org/t/evaluating-arbitrary-symbolic-expression-on-ode-solution/136130 "2026-03-11T09:23:56Z")

</div>

If I have an ODESolution, I can evaluate some variable at some t=5 with sol(5, idxs=sys.some\_variable), but what if I have EvalAt(15)(sys.some\_variable) - EvalAt(10)(sys.other\_variable). This is a reasonable expression t…

---

## [Polynomial optimization on a domain](https://discourse.julialang.org/t/polynomial-optimization-on-a-domain/135755)

<div class="topic-metadata">

**Author:** [@geo](https://discourse.julialang.org/u/geo)\
**Replies:** 4\
**Last updated:** [March 11, 2026, 8:31am UTC](https://discourse.julialang.org/t/polynomial-optimization-on-a-domain/135755 "2026-03-11T08:31:47Z")

</div>

As I understand polynomial optimization on a domain is based on the use of Putinar’s Positivestellensatz. Does this imply that the domain needs to be compact? Or am I misunderstanding something? The SumOfSquares manuals …

---

## [How to add padding to WGLMakie figure with resize\_to = :body](https://discourse.julialang.org/t/how-to-add-padding-to-wglmakie-figure-with-resize-to-body/135061)

<div class="topic-metadata">

**Author:** [@bjarthur](https://discourse.julialang.org/u/bjarthur)\
**Replies:** 4\
**Last updated:** [March 10, 2026, 4:06pm UTC](https://discourse.julialang.org/t/how-to-add-padding-to-wglmakie-figure-with-resize-to-body/135061 "2026-03-10T16:06:02Z")

</div>

when i use resize\_to = :body when activating WGLMakie so that the figure fills the browser window no matter what the size, a DOM.div element i have at the bottom gets clipped. like this (“hi”) in the lower left: is …

---

## [Why is Flux/NNlib falling back to im2col instead of MIOpen on AMD GPU?](https://discourse.julialang.org/t/why-is-flux-nnlib-falling-back-to-im2col-instead-of-miopen-on-amd-gpu/135867)

<div class="topic-metadata">

**Author:** [@ajrohr2](https://discourse.julialang.org/u/ajrohr2)\
**Replies:** 3\
**Last updated:** [March 10, 2026, 1:30am UTC](https://discourse.julialang.org/t/why-is-flux-nnlib-falling-back-to-im2col-instead-of-miopen-on-amd-gpu/135867 "2026-03-10T01:30:35Z")

</div>

Hello! I’ve been trying to get Flux’s convolutional layers, specifically the Flux.NNlib.conv! function, to use the MIOpen version rather than im2col or direct. I’ve verified that I have MIOpen available with AMDGPU.funct…

---

## [Add newline to LaTeXString equation](https://discourse.julialang.org/t/add-newline-to-latexstring-equation/95104)

<div class="topic-metadata">

**Author:** [@Nathan\_Boyer](https://discourse.julialang.org/u/Nathan_Boyer)\
**Replies:** 10\
**Last updated:** [March 9, 2026, 2:07pm UTC](https://discourse.julialang.org/t/add-newline-to-latexstring-equation/95104 "2026-03-09T14:07:35Z")

</div>

Hello, I have a LaTeXString which is too long to fit in one page-width. How can I add a line break to the equation so that it fits? I tried to add a \\\\ in the middle, but that didn’t change the rendering at all. julia\> …

---

## [Julia's SciML and UDE in temporal networks: preprint out](https://discourse.julialang.org/t/julias-sciml-and-ude-in-temporal-networks-preprint-out/136099)

<div class="topic-metadata">

**Author:** [@gvdr](https://discourse.julialang.org/u/gvdr)\
**Replies:** 1\
**Last updated:** [March 9, 2026, 10:37am UTC](https://discourse.julialang.org/t/julias-sciml-and-ude-in-temporal-networks-preprint-out/136099 "2026-03-09T10:37:07Z")

</div>

Hi everyone, I got a new pre-print out on arXiv, that uses the Julia’s SciML ecosystem quite a bit. The base idea is: if we consider a complex network that changes in time as a dynamical system (and take a nice model …

---

## [Hidden Markov Model with fixed parameters](https://discourse.julialang.org/t/hidden-markov-model-with-fixed-parameters/126710)

<div class="topic-metadata">

**Author:** [@simonsteiger](https://discourse.julialang.org/u/simonsteiger)\
**Replies:** 13\
**Last updated:** [March 7, 2026, 6:58am UTC](https://discourse.julialang.org/t/hidden-markov-model-with-fixed-parameters/126710 "2026-03-07T06:58:40Z")

</div>

I am trying to model a sequence of behaviours with two end points as a hidden markov model. To do this, I tried fixing some parameters in the transition and emission matrices, but I ran into the following error: MethodE…

---

## [Optimizing Lux.jl and Reactant.jl performance](https://discourse.julialang.org/t/optimizing-lux-jl-and-reactant-jl-performance/135942)

<div class="topic-metadata">

**Author:** [@KSepetanc](https://discourse.julialang.org/u/KSepetanc)\
**Replies:** 3\
**Last updated:** [March 6, 2026, 8:58pm UTC](https://discourse.julialang.org/t/optimizing-lux-jl-and-reactant-jl-performance/135942 "2026-03-06T20:58:07Z")

</div>

I am facing two separate issues. One is related to setting Reactant initialization options to improve performance and the other is about avoiding unnecessary latencies in neural network training loop via compilation. No…

---

## [GPU performance degradation due to 'A \\ B' calculation](https://discourse.julialang.org/t/gpu-performance-degradation-due-to-a-b-calculation/136072)

<div class="topic-metadata">

**Author:** [@WG-ZHENG](https://discourse.julialang.org/u/WG-ZHENG)\
**Replies:** 7\
**Last updated:** [March 6, 2026, 8:35pm UTC](https://discourse.julialang.org/t/gpu-performance-degradation-due-to-a-b-calculation/136072 "2026-03-06T20:35:30Z")

</div>

I was trying to accelerate my algorithm via CUDA.jl. Howerver, it is frustrating that the GPU version of the computing runs slower than the CPU one. The CPU version of key calculations in my algorithm is defined as belo…

---

## [Does AmplNLWriter support most of the functionalities that jump natively provides through MathOptInterface?](https://discourse.julialang.org/t/does-amplnlwriter-support-most-of-the-functionalities-that-jump-natively-provides-through-mathoptinterface/135939)

<div class="topic-metadata">

**Author:** [@Mihir\_V146](https://discourse.julialang.org/u/Mihir_V146)\
**Replies:** 7\
**Last updated:** [March 6, 2026, 2:00am UTC](https://discourse.julialang.org/t/does-amplnlwriter-support-most-of-the-functionalities-that-jump-natively-provides-through-mathoptinterface/135939 "2026-03-06T02:00:53Z")

</div>

I am trying to decide if I should start making some kind of MathOptInterface for my solver to make jump interface directly with it or should i just use the AmplNLWriter to indirectly talk to jump. The solver I have alrea…

---

## [Implementing custom learning rule in Neuroblox.jl](https://discourse.julialang.org/t/implementing-custom-learning-rule-in-neuroblox-jl/133063)

<div class="topic-metadata">

**Author:** [@dmaioli](https://discourse.julialang.org/u/dmaioli)\
**Replies:** 3\
**Last updated:** [March 5, 2026, 5:45pm UTC](https://discourse.julialang.org/t/implementing-custom-learning-rule-in-neuroblox-jl/133063 "2026-03-05T17:45:40Z")

</div>

Hi, I am interested in doing spiking neural networks simulations in Julia. The package Neuroblox.jl seems very promising, and the lectures posted on MIT OpenCourseware on it make it clear that it is possible to build cu…

---

## [Conditioning stochastic inflows on lagged state variables in SDDP.jl (PAR(p) model)](https://discourse.julialang.org/t/conditioning-stochastic-inflows-on-lagged-state-variables-in-sddp-jl-par-p-model/135757)

<div class="topic-metadata">

**Author:** [@MagnoOcarlos](https://discourse.julialang.org/u/MagnoOcarlos)\
**Replies:** 9\
**Last updated:** [March 4, 2026, 11:35pm UTC](https://discourse.julialang.org/t/conditioning-stochastic-inflows-on-lagged-state-variables-in-sddp-jl-par-p-model/135757 "2026-03-04T23:35:46Z")

</div>

Conditioning stochastic inflows on lagged state variables in SDDP.jl (PAR(p) model) Hi all, I’m implementing a hydrothermal dispatch model (similar to the Brazilian NEWAVE) using SDDP.jl. The inflow process follows a Pe…

---

## [MTK with MonteCarloMeasurements Error](https://discourse.julialang.org/t/mtk-with-montecarlomeasurements-error/135988)

<div class="topic-metadata">

**Author:** [@optimal\_georg](https://discourse.julialang.org/u/optimal_georg)\
**Replies:** 7\
**Last updated:** [March 4, 2026, 2:05pm UTC](https://discourse.julialang.org/t/mtk-with-montecarlomeasurements-error/135988 "2026-03-04T14:05:21Z")

</div>

Hi out there! I am trying to use MonteCarloMeasurements.jl together with MTK to solve a differential equation with uncertain parameters. using ModelingToolkit, DifferentialEquations using MonteCarloMeasurements using C…

[Previous page](https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=8)

[Next page](https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=10)