# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?page=18

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

**Page:** 19

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## [Seeking faster method for finding top eigenvalues of large dense matrices](https://discourse.julialang.org/t/seeking-faster-method-for-finding-top-eigenvalues-of-large-dense-matrices/134231)

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**Author:** [@Udonge](https://discourse.julialang.org/u/Udonge)\
**Replies:** 18\
**Last updated:** [December 4, 2025, 1:49pm UTC](https://discourse.julialang.org/t/seeking-faster-method-for-finding-top-eigenvalues-of-large-dense-matrices/134231 "2025-12-04T13:49:11Z")

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Hello everyone, I am new to the Julia language, and I’ve encountered a performance issue with an eigenvalue computation. Please feel free to point out any confusing statements or beginner mistakes! I need to compute th…

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## [Running external c-code function in MTK model](https://discourse.julialang.org/t/running-external-c-code-function-in-mtk-model/134265)

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**Author:** [@JulianMs](https://discourse.julialang.org/u/JulianMs)\
**Replies:** 7\
**Last updated:** [December 4, 2025, 8:59am UTC](https://discourse.julialang.org/t/running-external-c-code-function-in-mtk-model/134265 "2025-12-04T08:59:08Z")

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Hi community, I am new to Julia and in particular MTK. My goal is to simulate a battery cell and couple it with external C-code to run an extended Kalman filter for SOC estimation at a fixed sampling rate. Somehow thi…

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## [Laplacian regularisation for GLMs](https://discourse.julialang.org/t/laplacian-regularisation-for-glms/134154)

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**Author:** [@grero](https://discourse.julialang.org/u/grero)\
**Replies:** 10\
**Last updated:** [December 4, 2025, 2:59am UTC](https://discourse.julialang.org/t/laplacian-regularisation-for-glms/134154 "2025-12-04T02:59:52Z")

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I would like to use GLM to approximate an integer variable as following a Poisson distribution where the rate parameter is determined by a the independent variable X. X lives in a non-Euclidean space, and so using vanill…

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## [Failing to obtain a bifurcation plot](https://discourse.julialang.org/t/failing-to-obtain-a-bifurcation-plot/134330)

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**Author:** [@vembha](https://discourse.julialang.org/u/vembha)\
**Replies:** 0\
**Last updated:** [December 3, 2025, 3:47pm UTC](https://discourse.julialang.org/t/failing-to-obtain-a-bifurcation-plot/134330 "2025-12-03T15:47:51Z")

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Hello everyone, A long-time user of Julia/SciML. I have a system of ODEs and have been trying to obtain a bifurcation diagram using BifurcationKit.jl and ModelingToolkit.jl. While I am able to successfully obtain one br…

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## [How to evaluate a function y = f(x) for x in Interval defined by Domainset?](https://discourse.julialang.org/t/how-to-evaluate-a-function-y-f-x-for-x-in-interval-defined-by-domainset/134300)

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**Author:** [@ziolai](https://discourse.julialang.org/u/ziolai)\
**Replies:** 4\
**Last updated:** [December 3, 2025, 7:57am UTC](https://discourse.julialang.org/t/how-to-evaluate-a-function-y-f-x-for-x-in-interval-defined-by-domainset/134300 "2025-12-03T07:57:21Z")

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How to evaluate a function y = f(x) for x in an interval defined by IntervalSets.jl ? using DomainSets I = Interval(0,1.) foo(x) = x^2 How to \[foo(x) for x ∈ I\] or map(foo,I) ?

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## [Policy Graph in SDDP.jl package](https://discourse.julialang.org/t/policy-graph-in-sddp-jl-package/100062)

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**Author:** [@Sorooshsa](https://discourse.julialang.org/u/Sorooshsa)\
**Replies:** 3\
**Last updated:** [December 3, 2025, 4:59am UTC](https://discourse.julialang.org/t/policy-graph-in-sddp-jl-package/100062 "2025-12-03T04:59:08Z")

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Hi, I know that there are a few options for making the graph of our problem while we use SDDP.jl e.g. linear policy graph, Markov policy graph. I have two questions: What is the difference between the Linear and Mark…

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## [Features of FMUGeneration](https://discourse.julialang.org/t/features-of-fmugeneration/132812)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 11\
**Last updated:** [December 3, 2025, 4:54am UTC](https://discourse.julialang.org/t/features-of-fmugeneration/132812 "2025-12-03T04:54:05Z")

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The package FMUGeneration works for me now (see here). Follow-up questions: Is an FMU file always OS specific? Do I need three of them if I want to support Windows, Mac, and Linux? Does the user of an FMU need to have …

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## [RepliBuild.jl](https://discourse.julialang.org/t/replibuild-jl/134065)

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**Author:** [@obsidianjulua](https://discourse.julialang.org/u/obsidianjulua)\
**Replies:** 10\
**Last updated:** [December 2, 2025, 7:34pm UTC](https://discourse.julialang.org/t/replibuild-jl/134065 "2025-12-02T19:34:10Z")

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Been working on a julia build orchestrator, using llvm directly and clang for deps graphs and configuring to a toml, generating executables, shared libraries, or binary wrapping in julia, without the traditional hand cod…

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## [What is the most ideal predictor for predicting binary vectors?](https://discourse.julialang.org/t/what-is-the-most-ideal-predictor-for-predicting-binary-vectors/134260)

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**Author:** [@WuSiren](https://discourse.julialang.org/u/WuSiren)\
**Replies:** 6\
**Last updated:** [December 2, 2025, 3:13pm UTC](https://discourse.julialang.org/t/what-is-the-most-ideal-predictor-for-predicting-binary-vectors/134260 "2025-12-02T15:13:59Z")

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I want to predict a vector whose elements are binary. What is the most promising machine learning model for doing this at present? Is there a corresponding Julia package?

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## [Testing and tolerances for implicitly calculated functions and their AD](https://discourse.julialang.org/t/testing-and-tolerances-for-implicitly-calculated-functions-and-their-ad/133575)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 3\
**Last updated:** [December 2, 2025, 12:49pm UTC](https://discourse.julialang.org/t/testing-and-tolerances-for-implicitly-calculated-functions-and-their-ad/133575 "2025-12-02T12:49:17Z")

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To fix ideas, suppose we have a function x = g(p) defined by f(x(p), p) = 0, both arguments are scalars. The numerical implementation involves finding an x such that | f(x, p)| \\le \\mathrm{tol}, either by Newton’s metho…

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## [Modeling min() in JuMP at scale: SOS1 stops converging, Big-M is numerically unstable](https://discourse.julialang.org/t/modeling-min-in-jump-at-scale-sos1-stops-converging-big-m-is-numerically-unstable/134251)

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**Author:** [@Bhanuprakash\_Bahoju](https://discourse.julialang.org/u/Bhanuprakash_Bahoju)\
**Replies:** 11\
**Last updated:** [December 2, 2025, 11:13am UTC](https://discourse.julialang.org/t/modeling-min-in-jump-at-scale-sos1-stops-converging-big-m-is-numerically-unstable/134251 "2025-12-02T11:13:52Z")

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I’m implementing a formula engine in JuMP where users can define expressions like: z = min(x, y) and I translate these automatically into JuMP constraints. I have tried two formulations: 1. SOS1 formulation function…

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## [Png(p, file\_name) always shows the plot \[Plots.jl, GR\]](https://discourse.julialang.org/t/png-p-file-name-always-shows-the-plot-plots-jl-gr/134225)

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**Author:** [@AdamWysokinski](https://discourse.julialang.org/u/AdamWysokinski)\
**Replies:** 1\
**Last updated:** [December 1, 2025, 5:28pm UTC](https://discourse.julialang.org/t/png-p-file-name-always-shows-the-plot-plots-jl-gr/134225 "2025-12-01T17:28:49Z")

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Hi, I think the behaviour of show() has changed recently. Calling: using Plots p = plot(rand(10)); png(p, tempname()) always shows the plot. Same for: using Plots p = plot(rand(10)); io = PipeBuffer() png(p, io); # …

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## [ForwardDiff with ModelingToolkit: Type conversion error in MTKParameters with DAE systems](https://discourse.julialang.org/t/forwarddiff-with-modelingtoolkit-type-conversion-error-in-mtkparameters-with-dae-systems/134145)

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**Author:** [@Danijel-Zadravec](https://discourse.julialang.org/u/Danijel-Zadravec)\
**Replies:** 2\
**Last updated:** [December 1, 2025, 12:21pm UTC](https://discourse.julialang.org/t/forwarddiff-with-modelingtoolkit-type-conversion-error-in-mtkparameters-with-dae-systems/134145 "2025-12-01T12:21:26Z")

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Hi everyone, I’m encountering a MethodError when trying to follow this example from the ModelingToolkit documentation. The problem seems to be related with dual number propagation in ODEProblems that have the property: …

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## [Adaptive barrier method for constrained optimization](https://discourse.julialang.org/t/adaptive-barrier-method-for-constrained-optimization/134150)

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**Author:** [@slwu89](https://discourse.julialang.org/u/slwu89)\
**Replies:** 6\
**Last updated:** [December 1, 2025, 8:57am UTC](https://discourse.julialang.org/t/adaptive-barrier-method-for-constrained-optimization/134150 "2025-12-01T08:57:32Z")

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Hi all, I’m refactoring some old R code into Julia. In R I was using constrOptim: Linearly Constrained Optimization which lets us use constraints like U \\theta - c \\geq 0, where \\theta is our parameters to be optimized, U…

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## [Lagrange multipliers of a \`VectorNonlinearOracle\` after solve](https://discourse.julialang.org/t/lagrange-multipliers-of-a-vectornonlinearoracle-after-solve/134236)

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**Author:** [@franckgaga](https://discourse.julialang.org/u/franckgaga)\
**Replies:** 1\
**Last updated:** [November 30, 2025, 7:39pm UTC](https://discourse.julialang.org/t/lagrange-multipliers-of-a-vectornonlinearoracle-after-solve/134236 "2025-11-30T19:39:32Z")

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I have a nonlinear optimization problem that relies on MOI.VectorNonlinearOracle for the constraints. I would like to compute the Hessian of the Langrangian at the optimum after solving, or, in other words, fetching the r…

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## [ChainRules error when using Mooncake in Optimization.jl](https://discourse.julialang.org/t/chainrules-error-when-using-mooncake-in-optimization-jl/134240)

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**Author:** [@slwu89](https://discourse.julialang.org/u/slwu89)\
**Replies:** 0\
**Last updated:** [November 30, 2025, 7:10pm UTC](https://discourse.julialang.org/t/chainrules-error-when-using-mooncake-in-optimization-jl/134240 "2025-11-30T19:10:28Z")

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Hi all, I am testing out using the SciML ecosystem to fit constrained splines inside of an ODE (some terms on the RHS of the ODE are given by evaluating a spline where the point of evaluation on the domain of the spline …

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## [KernelAbstractions + CUDA + Reactant - how to get minimal working example](https://discourse.julialang.org/t/kernelabstractions-cuda-reactant-how-to-get-minimal-working-example/134164)

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**Author:** [@Jakub\_Mitura](https://discourse.julialang.org/u/Jakub_Mitura)\
**Replies:** 12\
**Last updated:** [November 30, 2025, 6:34am UTC](https://discourse.julialang.org/t/kernelabstractions-cuda-reactant-how-to-get-minimal-working-example/134164 "2025-11-30T06:34:06Z")

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Hello I tried to get minimal working example for reactant powered kernel abstractions plus Enzyme like using Pkg Pkg.activate(".") using Reactant using KernelAbstractions using CUDA using Enzyme using Test # Simple squ…

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## [Best way to model a piecewise linearization for \`f(x) = x^0.8\` on \`\[0, 1e5\]\` with PiecewiseLinearOpt.jl?](https://discourse.julialang.org/t/best-way-to-model-a-piecewise-linearization-for-f-x-x-0-8-on-0-1e5-with-piecewiselinearopt-jl/131963)

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**Author:** [@karei](https://discourse.julialang.org/u/karei)\
**Replies:** 3\
**Last updated:** [November 28, 2025, 10:39am UTC](https://discourse.julialang.org/t/best-way-to-model-a-piecewise-linearization-for-f-x-x-0-8-on-0-1e5-with-piecewiselinearopt-jl/131963 "2025-11-28T10:39:13Z")

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Hi all, I have an optimization model where I need to replace a concave cost term f(x) = x^{0.8} for x \\in \[0, 10^5\] with a piecewise linear (PWL) form in JuMP. The model is a minimization, and I’m considering using Pie…

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## [DiffOpt / JuMP: zero gradient for variable fixed by equality constraint](https://discourse.julialang.org/t/diffopt-jump-zero-gradient-for-variable-fixed-by-equality-constraint/134041)

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**Author:** [@yeomoon](https://discourse.julialang.org/u/yeomoon)\
**Replies:** 12\
**Last updated:** [November 28, 2025, 5:36am UTC](https://discourse.julialang.org/t/diffopt-jump-zero-gradient-for-variable-fixed-by-equality-constraint/134041 "2025-11-28T05:36:03Z")

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Hi all, I’m trying to train a neural network that is followed by a differentiable optimization layer in Julia. Conceptually it’s: Flux NN → Economic Dispatch layer (ED layer) → Loss The ED layer is implemented as a …

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## [L-moment package?](https://discourse.julialang.org/t/l-moment-package/54536)

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**Author:** [@tomtom](https://discourse.julialang.org/u/tomtom)\
**Replies:** 1\
**Last updated:** [November 28, 2025, 2:00am UTC](https://discourse.julialang.org/t/l-moment-package/54536 "2025-11-28T02:00:13Z")

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hello, I wonder if L-moment related summary statistics are available in any Julia package? thanks.

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## [Meshgrid function in Julia](https://discourse.julialang.org/t/meshgrid-function-in-julia/48679)

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**Author:** [@Hrishikesh\_Das](https://discourse.julialang.org/u/Hrishikesh_Das)\
**Replies:** 35\
**Last updated:** [November 27, 2025, 11:05am UTC](https://discourse.julialang.org/t/meshgrid-function-in-julia/48679 "2025-11-27T11:05:15Z")

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hello everyone I am new to Julia. Earlier I was using Matlab but now I have started to work in Julia. I would like to know is there any similar function available in julia like Meshgrid which is available in matlab. Plea…

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## [ModelingToolkit fails to precompile on Julia 1.12 (UndefVarError: ODESystem not defined in ModelingToolkit)](https://discourse.julialang.org/t/modelingtoolkit-fails-to-precompile-on-julia-1-12-undefvarerror-odesystem-not-defined-in-modelingtoolkit/134133)

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**Author:** [@junmorenodi99](https://discourse.julialang.org/u/junmorenodi99)\
**Replies:** 11\
**Last updated:** [November 27, 2025, 7:56am UTC](https://discourse.julialang.org/t/modelingtoolkit-fails-to-precompile-on-julia-1-12-undefvarerror-odesystem-not-defined-in-modelingtoolkit/134133 "2025-11-27T07:56:46Z")

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Hi everyone, I’m having trouble with ModelingToolkit precompilation on Julia 1.12 on Windows, and I can’t figure out what’s triggering it. In my project I’m just adding some libraries (including ModelingToolkit) : usi…

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## [Plots with log or symlog scale](https://discourse.julialang.org/t/plots-with-log-or-symlog-scale/15961)

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**Author:** [@aplavin](https://discourse.julialang.org/u/aplavin)\
**Replies:** 5\
**Last updated:** [November 27, 2025, 1:49am UTC](https://discourse.julialang.org/t/plots-with-log-or-symlog-scale/15961 "2025-11-27T01:49:35Z")

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I’m trying to make plots with log and symlog scales, but no success with Plots.jl so far. When I try cgrad(scale=:log) it gives strange results, see below. And there seem to be no other place to specify log-scale. A = r…

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## [ModelingToolkit: How to interpret "ERROR: Cyclic guesses detected in the system" during initialization?](https://discourse.julialang.org/t/modelingtoolkit-how-to-interpret-error-cyclic-guesses-detected-in-the-system-during-initialization/134146)

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**Author:** [@NicholasHemenway](https://discourse.julialang.org/u/NicholasHemenway)\
**Replies:** 2\
**Last updated:** [November 26, 2025, 10:52pm UTC](https://discourse.julialang.org/t/modelingtoolkit-how-to-interpret-error-cyclic-guesses-detected-in-the-system-during-initialization/134146 "2025-11-26T22:52:07Z")

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I’ve got a simple RC circuit with two series resistors: using ModelingToolkit, DifferentialEquations using ModelingToolkitStandardLibrary.Electrical using ModelingToolkitStandardLibrary.Blocks @mtkmodel Circuit begin …

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## [CairoMakie.jl, MathTeXEngine.jl, Small Caps](https://discourse.julialang.org/t/cairomakie-jl-mathtexengine-jl-small-caps/133985)

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**Author:** [@mpirke](https://discourse.julialang.org/u/mpirke)\
**Replies:** 7\
**Last updated:** [November 26, 2025, 8:35pm UTC](https://discourse.julialang.org/t/cairomakie-jl-mathtexengine-jl-small-caps/133985 "2025-11-26T20:35:54Z")

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Hi there! I have been struggling for the last hour with the following issue. I want to have a word in small caps within my legend in a CairoMakie plot. To get a word in small caps in Latex I just do \\textsc{Foo}. Her…

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## [Use of global variables for defining default values in ModelingToolkit bad?](https://discourse.julialang.org/t/use-of-global-variables-for-defining-default-values-in-modelingtoolkit-bad/134123)

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**Author:** [@NicholasHemenway](https://discourse.julialang.org/u/NicholasHemenway)\
**Replies:** 3\
**Last updated:** [November 26, 2025, 4:52pm UTC](https://discourse.julialang.org/t/use-of-global-variables-for-defining-default-values-in-modelingtoolkit-bad/134123 "2025-11-26T16:52:48Z")

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I’m not sure how scoping is handled when constructing and subsequently simulating a ModelingToolkit model. Would the following code be “bad practice” since the default references a globally scoped variable? Or is only th…

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## [MadNLPGPU.jl not working for simple economic dispatch](https://discourse.julialang.org/t/madnlpgpu-jl-not-working-for-simple-economic-dispatch/134084)

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**Author:** [@shakedregev](https://discourse.julialang.org/u/shakedregev)\
**Replies:** 4\
**Last updated:** [November 26, 2025, 3:14pm UTC](https://discourse.julialang.org/t/madnlpgpu-jl-not-working-for-simple-economic-dispatch/134084 "2025-11-26T15:14:01Z")

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I’m having issues using MadNLPGPU.jl, while a similar code works for MadNLP.jl. I initially tried a direct conversion, then I read that Examodels is better for GPUs. I am not attached to the particular method to solve on…

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## [Potential issues with implementation of ziggurat algorithm](https://discourse.julialang.org/t/potential-issues-with-implementation-of-ziggurat-algorithm/134130)

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**Author:** [@MrBelette](https://discourse.julialang.org/u/MrBelette)\
**Replies:** 0\
**Last updated:** [November 26, 2025, 2:03am UTC](https://discourse.julialang.org/t/potential-issues-with-implementation-of-ziggurat-algorithm/134130 "2025-11-26T02:03:09Z")

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I’m seeing intermittent failures to finish issues when repeatedly running a kernel that calls randn many times. I’m wondering if someone can independently verify this behaviour, so I can decide if a bug needs to be repo…

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## [ContinuousCallback in DifferentialEquations.jl for the The Izhikevich Model](https://discourse.julialang.org/t/continuouscallback-in-differentialequations-jl-for-the-the-izhikevich-model/133883)

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**Author:** [@mongi](https://discourse.julialang.org/u/mongi)\
**Replies:** 7\
**Last updated:** [November 25, 2025, 2:52pm UTC](https://discourse.julialang.org/t/continuouscallback-in-differentialequations-jl-for-the-the-izhikevich-model/133883 "2025-11-25T14:52:52Z")

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Greetings, Is it possible to get the The Izhikevich Model to work with ContinuousCallback as the DiscreteCallback is not accurate near the zero-crossing. # function reset!(integrator) # @show integrator.u\[1\], integr…

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## [Parallelism within Turing.jl model](https://discourse.julialang.org/t/parallelism-within-turing-jl-model/54064)

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**Author:** [@EvoArt](https://discourse.julialang.org/u/EvoArt)\
**Replies:** 10\
**Last updated:** [November 25, 2025, 2:08pm UTC](https://discourse.julialang.org/t/parallelism-within-turing-jl-model/54064 "2025-11-25T14:08:40Z")

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Hi there, just wondering how safe it is to use Threads.@threads for loops within turing models e.g. @model function my\_func(Y) alpha ~ Normal(0,1) sigma ~ Normal(0,1) Threads.@threads for i in 1:size(Y)\[2…

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