# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=56

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**Page:** 57

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## [Help using cuDNN in Julia](https://discourse.julialang.org/t/help-using-cudnn-in-julia/126232)

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**Author:** [@notGiGi](https://discourse.julialang.org/u/notGiGi)\
**Replies:** 1\
**Last updated:** [February 25, 2025, 5:02pm UTC](https://discourse.julialang.org/t/help-using-cudnn-in-julia/126232 "2025-02-25T17:02:52Z")

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Hello, everyone. I’m trying to use cuDNN in Julia, but so far it’s not working as expected. I’m very confused. It is supposed to be included in CUDA.jl so that I can use using CUDA.CUDNN, but when I do that, I get the er…

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## [ModelingToolkit and Noise Processes for uniform noise definition](https://discourse.julialang.org/t/modelingtoolkit-and-noise-processes-for-uniform-noise-definition/126291)

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**Author:** [@NinaOmejc](https://discourse.julialang.org/u/NinaOmejc)\
**Replies:** 8\
**Last updated:** [February 25, 2025, 3:50pm UTC](https://discourse.julialang.org/t/modelingtoolkit-and-noise-processes-for-uniform-noise-definition/126291 "2025-02-25T15:50:15Z")

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Hi, I am using MTK to set up a hierarchical dynamical system. As the input to the (otherwise ODE) system can also be random uniform noise, I need to set up SDESystem (instead of ODESystem). However, I cannot find out ho…

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## [Strang Splitting with SplitODEProblem](https://discourse.julialang.org/t/strang-splitting-with-splitodeproblem/126255)

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**Author:** [@svretina](https://discourse.julialang.org/u/svretina)\
**Replies:** 2\
**Last updated:** [February 25, 2025, 3:27pm UTC](https://discourse.julialang.org/t/strang-splitting-with-splitodeproblem/126255 "2025-02-25T15:27:46Z")

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Hi all, I am interested in implementing a split ODE problem, I am solving the wave equation with a Finite Volume scheme such as MUSCL with a discontinuous source term. I want to implement a fractional step method and …

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## [Matrices and tensors with Symbolics.jl](https://discourse.julialang.org/t/matrices-and-tensors-with-symbolics-jl/119394)

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**Author:** [@Damiano](https://discourse.julialang.org/u/Damiano)\
**Replies:** 6\
**Last updated:** [February 25, 2025, 1:29pm UTC](https://discourse.julialang.org/t/matrices-and-tensors-with-symbolics-jl/119394 "2025-02-25T13:29:04Z")

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Hi all, three quick issues I encountered. Please correct me if I should have created different topics of if the Category is wrong. Best way to create a symmetric matrix This is the best I could come up with. A = Ar…

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## [Hidedecorations not working as expected for PolarAxis?](https://discourse.julialang.org/t/hidedecorations-not-working-as-expected-for-polaraxis/126231)

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**Author:** [@grero](https://discourse.julialang.org/u/grero)\
**Replies:** 2\
**Last updated:** [February 25, 2025, 1:17am UTC](https://discourse.julialang.org/t/hidedecorations-not-working-as-expected-for-polaraxis/126231 "2025-02-25T01:17:42Z")

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I’m putting together a fairly complicated figure, involving a mixture of line plots and polar histogram plots. Using PolarAxis for the latter, I found that they appear to take up more space than needed. To illustrate the…

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## [Re-creating MTK problems creates side effects (ModelingToolkit.jl)](https://discourse.julialang.org/t/re-creating-mtk-problems-creates-side-effects-modelingtoolkit-jl/126054)

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**Author:** [@ysfoo](https://discourse.julialang.org/u/ysfoo)\
**Replies:** 3\
**Last updated:** [February 24, 2025, 11:27pm UTC](https://discourse.julialang.org/t/re-creating-mtk-problems-creates-side-effects-modelingtoolkit-jl/126054 "2025-02-24T23:27:51Z")

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I am following the somewhat recent tutorial on re-creating MTK problems. In summary, the function loss is defined, which remakes an ODEProblem by replacing the tunable portion of the parameters with the input argument, a…

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## [Anyone have a working BBL implementation?](https://discourse.julialang.org/t/anyone-have-a-working-bbl-implementation/126266)

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**Author:** [@floswald](https://discourse.julialang.org/u/floswald)\
**Replies:** 0\
**Last updated:** [February 24, 2025, 9:18pm UTC](https://discourse.julialang.org/t/anyone-have-a-working-bbl-implementation/126266 "2025-02-24T21:18:30Z")

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Do any empirical IO folks on here have a working implementation of the BBL algorithm (Victor Aguirregabiria's Website - Computer Code) ? I did download the BBL code from there I now have GAUSS25. Erm…yeah. I find it ve…

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## [OPC UA package? ( Open Platform Communications Unified Architecture)](https://discourse.julialang.org/t/opc-ua-package-open-platform-communications-unified-architecture/94336)

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**Author:** [@ohmsweetohm1](https://discourse.julialang.org/u/ohmsweetohm1)\
**Replies:** 15\
**Last updated:** [February 24, 2025, 8:29pm UTC](https://discourse.julialang.org/t/opc-ua-package-open-platform-communications-unified-architecture/94336 "2025-02-24T20:29:56Z")

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Is there a Julia version of python-opcua or something equivalent?

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## [Different behaviour of contour in Plots and GLMakie](https://discourse.julialang.org/t/different-behaviour-of-contour-in-plots-and-glmakie/126247)

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**Author:** [@vtfanta](https://discourse.julialang.org/u/vtfanta)\
**Replies:** 4\
**Last updated:** [February 24, 2025, 7:51pm UTC](https://discourse.julialang.org/t/different-behaviour-of-contour-in-plots-and-glmakie/126247 "2025-02-24T19:51:39Z")

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When plotting a contour plot of a quadratic, behaviour is different for Plots and Makie, while Makie is correct. The motivation is to show an iteration of the Newton method. ▶ MWE Makie correctly shows the minimizer in t…

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## [Using Second-Order Cone Constraints with Logarithms in JuMP and Gurobi's C API](https://discourse.julialang.org/t/using-second-order-cone-constraints-with-logarithms-in-jump-and-gurobis-c-api/125769)

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**Author:** [@Beyza\_Aydin](https://discourse.julialang.org/u/Beyza_Aydin)\
**Replies:** 7\
**Last updated:** [February 24, 2025, 7:47pm UTC](https://discourse.julialang.org/t/using-second-order-cone-constraints-with-logarithms-in-jump-and-gurobis-c-api/125769 "2025-02-24T19:47:28Z")

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Hello, I am using JuMP with the Gurobi optimizer to solve a problem involving both second-order cone constraints and logarithmic constraints. I want to model the constraint ||x||\_1 \>= K\*||x||\_2 which I coded as: const…

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## [First solve of \`ODEProblem\` and running out of memory: compilation problems?](https://discourse.julialang.org/t/first-solve-of-odeproblem-and-running-out-of-memory-compilation-problems/126160)

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**Author:** [@johannesnauta](https://discourse.julialang.org/u/johannesnauta)\
**Replies:** 3\
**Last updated:** [February 24, 2025, 10:58am UTC](https://discourse.julialang.org/t/first-solve-of-odeproblem-and-running-out-of-memory-compilation-problems/126160 "2025-02-24T10:58:33Z")

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Hey it’s me again, I keep encountering memory-related issues with the first call to solve(prob), where prob is an ODEProblem (see details below). While this is probably expected, as it is most likely related to the “tim…

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## [Save JuMP Model to File](https://discourse.julialang.org/t/save-jump-model-to-file/126220)

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**Author:** [@Stuart\_Rogers](https://discourse.julialang.org/u/Stuart_Rogers)\
**Replies:** 2\
**Last updated:** [February 23, 2025, 8:38pm UTC](https://discourse.julialang.org/t/save-jump-model-to-file/126220 "2025-02-23T20:38:07Z")

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I want to save a JuMP model to a .MPS file without appending .MPS to the filename in the second argument to write\_to\_file, .i.e. not using write\_to\_file(model,"test.MPS"). The approach below does not work. julia\> usi…

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## [Simulating SDEs with shared noise in \`DifferentialEquations.jl\`](https://discourse.julialang.org/t/simulating-sdes-with-shared-noise-in-differentialequations-jl/126139)

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**Author:** [@NoFishLikeIan](https://discourse.julialang.org/u/NoFishLikeIan)\
**Replies:** 2\
**Last updated:** [February 23, 2025, 5:17pm UTC](https://discourse.julialang.org/t/simulating-sdes-with-shared-noise-in-differentialequations-jl/126139 "2025-02-23T17:17:01Z")

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I have a problem with two processes X\_{1, t}, X\_{2, t} \\in \\mathbb{R} which satisfy the SDEs \\begin{align} dX\_{1, t} = f\_1(t, X\_{1, t}) \\; dt + \\sigma \\; dW\_t, \\\\ dX\_{2, t} = f\_2(t, X\_{1, t}) \\; dt + \\sigma \\; dW\_t. \\en…

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## [Constraints of type MathOptInterface.ScalarNonlinearFunction-in-MathOptInterface.LessThan{Float64} are not supported by the solver](https://discourse.julialang.org/t/constraints-of-type-mathoptinterface-scalarnonlinearfunction-in-mathoptinterface-lessthan-float64-are-not-supported-by-the-solver/126178)

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**Author:** [@leonie25](https://discourse.julialang.org/u/leonie25)\
**Replies:** 7\
**Last updated:** [February 23, 2025, 4:20am UTC](https://discourse.julialang.org/t/constraints-of-type-mathoptinterface-scalarnonlinearfunction-in-mathoptinterface-lessthan-float64-are-not-supported-by-the-solver/126178 "2025-02-23T04:20:46Z")

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I am working on an optimization problem and build a model using Gurobi Optimizer with JuMP. It has some nonlinear constraints: @constraint(model, f\[i\] + func(qe\[i\])\<= M1 \* (1 - x\[(i, j)\]) + f\[j\]) where f, qe, x are non…

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## [How does a kernel function in KernelAbstractions.jl work when the backend is a CPU?](https://discourse.julialang.org/t/how-does-a-kernel-function-in-kernelabstractions-jl-work-when-the-backend-is-a-cpu/126173)

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**Author:** [@frankwswang](https://discourse.julialang.org/u/frankwswang)\
**Replies:** 1\
**Last updated:** [February 22, 2025, 4:59pm UTC](https://discourse.julialang.org/t/how-does-a-kernel-function-in-kernelabstractions-jl-work-when-the-backend-is-a-cpu/126173 "2025-02-22T16:59:50Z")

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I’m trying to add GPU-based parallelization to my code. I found KernelAbstractions.jl and liked its backend (vendor) agnostic approach, especially the fall-back support for CPU multi-threading. However, I didn’t find de…

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## [Forward Automatic Differentiation & FFTs](https://discourse.julialang.org/t/forward-automatic-differentiation-ffts/126036)

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**Author:** [@marcobonici](https://discourse.julialang.org/u/marcobonici)\
**Replies:** 13\
**Last updated:** [February 22, 2025, 10:18pm UTC](https://discourse.julialang.org/t/forward-automatic-differentiation-ffts/126036 "2025-02-22T22:18:37Z")

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I need to understand if there is a combination of packages that is able to wdo what I need. I need to do some FFTs, differentiate through them both in Forward and Backward mode with one of the Julia AD engines (it might…

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## [JuMP: declaring a vector of PSD matrices](https://discourse.julialang.org/t/jump-declaring-a-vector-of-psd-matrices/126179)

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**Author:** [@healyp](https://discourse.julialang.org/u/healyp)\
**Replies:** 1\
**Last updated:** [February 22, 2025, 6:48pm UTC](https://discourse.julialang.org/t/jump-declaring-a-vector-of-psd-matrices/126179 "2025-02-22T18:48:47Z")

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in JuMP it’s very straightforward to declare a PSD matrix variable. If S \\succeq 0, I can simply say @variable(m, S\[1:4,1:4\], PSD) But if I now want a set, or vector, of them, like, S\_i \\succeq 0, i \\in \[1,\\ldots,k\] I…

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## [Quiver plot using PlotlyJS backend not showing arrowhead](https://discourse.julialang.org/t/quiver-plot-using-plotlyjs-backend-not-showing-arrowhead/102144)

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**Author:** [@jinfreedom](https://discourse.julialang.org/u/jinfreedom)\
**Replies:** 4\
**Last updated:** [February 22, 2025, 2:16am UTC](https://discourse.julialang.org/t/quiver-plot-using-plotlyjs-backend-not-showing-arrowhead/102144 "2025-02-22T02:16:07Z")

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Hi, I’m using plotlyjs backend to make a simple quiver plot, it looks like this where arrow heads are not shown. If I switch to GR I get the following wit arrow heads So how do I make arrow heads shown with plotl…

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## [Using ApproxFun.jl to solve a Volterra equation of the second kind](https://discourse.julialang.org/t/using-approxfun-jl-to-solve-a-volterra-equation-of-the-second-kind/40203)

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**Author:** [@chisquared](https://discourse.julialang.org/u/chisquared)\
**Replies:** 4\
**Last updated:** [February 21, 2025, 5:35pm UTC](https://discourse.julialang.org/t/using-approxfun-jl-to-solve-a-volterra-equation-of-the-second-kind/40203 "2025-02-21T17:35:00Z")

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I’m trying to learn how to solve Volterra equations of the second kind using ApproxFun.jl. For example, consider the following equation, where u is an unknown function on \[0,1/2\]. The closest similar example I could …

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## [Building mass and stiffness matrix for time dependent PDE with Gridap](https://discourse.julialang.org/t/building-mass-and-stiffness-matrix-for-time-dependent-pde-with-gridap/126164)

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**Author:** [@Cirdans-Home](https://discourse.julialang.org/u/Cirdans-Home)\
**Replies:** 0\
**Last updated:** [February 21, 2025, 5:29pm UTC](https://discourse.julialang.org/t/building-mass-and-stiffness-matrix-for-time-dependent-pde-with-gridap/126164 "2025-02-21T17:29:58Z")

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Hi, I have implemented an algorithm for the solution of system of ODEs that I want to test against a method of line discretization of a PDE. My routine needs to take as input the mass matrix (assumed to be time-indepen…

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## [Title below plot](https://discourse.julialang.org/t/title-below-plot/126152)

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**Author:** [@Breizhen](https://discourse.julialang.org/u/Breizhen)\
**Replies:** 1\
**Last updated:** [February 21, 2025, 3:46pm UTC](https://discourse.julialang.org/t/title-below-plot/126152 "2025-02-21T15:46:11Z")

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Is there any way to place the title(s) below a plot or subplots using Plots.jl, without getting around the problem and using the ‘annotate’ function?

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## [Symbolics substitute - what has changed?](https://discourse.julialang.org/t/symbolics-substitute-what-has-changed/116826)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 9\
**Last updated:** [February 21, 2025, 11:11am UTC](https://discourse.julialang.org/t/symbolics-substitute-what-has-changed/116826 "2025-02-21T11:11:51Z")

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What has changed with Symbolics substitute? In the past, I could compose two substitutions, but that doesn’t seem to work any more. Concretely, I consider: Asn = substitute(As, Dict(name\_s .=\> s\_ss)) |\> x -\> substitute…

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## [Can't get the expected resolution using Rasters.resample](https://discourse.julialang.org/t/cant-get-the-expected-resolution-using-rasters-resample/126118)

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**Author:** [@MJulia](https://discourse.julialang.org/u/MJulia)\
**Replies:** 2\
**Last updated:** [February 21, 2025, 2:25am UTC](https://discourse.julialang.org/t/cant-get-the-expected-resolution-using-rasters-resample/126118 "2025-02-21T02:25:04Z")

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I tried the following code snippet to resample high-resolution data to a lower resolution. The first method works, but the second one doesn’t. It seems I missed some parameters for the “to” keyword in the resample functi…

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## [How do I properly close a DuckDb database?](https://discourse.julialang.org/t/how-do-i-properly-close-a-duckdb-database/100598)

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**Author:** [@kobusherbst](https://discourse.julialang.org/u/kobusherbst)\
**Replies:** 20\
**Last updated:** [February 21, 2025, 1:44am UTC](https://discourse.julialang.org/t/how-do-i-properly-close-a-duckdb-database/100598 "2025-02-21T01:44:28Z")

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I cannot run the following code twice in one julia session: using DuckDB using DBInterface db = DuckDB.DB("C:\\\\Temp\\\\test.duckdb") t = DBInterface.execute(db, "SELECT 1") DuckDB.close\_database(db) On the second run …

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## [How to construct a categorical colormap with one specific value corresponding to a specific color?](https://discourse.julialang.org/t/how-to-construct-a-categorical-colormap-with-one-specific-value-corresponding-to-a-specific-color/126114)

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**Author:** [@thudjx](https://discourse.julialang.org/u/thudjx)\
**Replies:** 0\
**Last updated:** [February 20, 2025, 1:32pm UTC](https://discourse.julialang.org/t/how-to-construct-a-categorical-colormap-with-one-specific-value-corresponding-to-a-specific-color/126114 "2025-02-20T13:32:11Z")

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What I want to do: I have an array of intergers that ranges over -3:2, which I want to plot with heatmap. The difficult part is that I want the 0 to be ploted by some “neutral” color, say grey in the colormap :coolwarm. …

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## [How to perform a sparse matrix dense matrix product with addition (cuda library style)](https://discourse.julialang.org/t/how-to-perform-a-sparse-matrix-dense-matrix-product-with-addition-cuda-library-style/126093)

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**Author:** [@victor\_vhrn](https://discourse.julialang.org/u/victor_vhrn)\
**Replies:** 1\
**Last updated:** [February 20, 2025, 7:33am UTC](https://discourse.julialang.org/t/how-to-perform-a-sparse-matrix-dense-matrix-product-with-addition-cuda-library-style/126093 "2025-02-20T07:33:09Z")

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I want to compute the following result = -1 \* (e \* (e' \* U)) + M \* U Where e = ones(n,1), M is a n x n CuSparseMatrixCSR and U is a n x r dense CuMatrix. Since it is my understanding that the above operation invokes 4…

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## [ModelingToolkit -- changes with \`remake\`?](https://discourse.julialang.org/t/modelingtoolkit-changes-with-remake/126004)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 2\
**Last updated:** [February 19, 2025, 7:07pm UTC](https://discourse.julialang.org/t/modelingtoolkit-changes-with-remake/126004 "2025-02-19T19:07:19Z")

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I have a @mtkbuild model named hp\_na\_ns\_oL which uses some register\_symbolic function u\_u\_v(t) that I specify via a constant value function u\_v\_const(). I want to simulate the system to steady state, and use the steady s…

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## [MultiObjectiveAlgorithms.jl (skipping infeasible solutions)](https://discourse.julialang.org/t/multiobjectivealgorithms-jl-skipping-infeasible-solutions/126003)

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**Author:** [@saikrishna-nadella](https://discourse.julialang.org/u/saikrishna-nadella)\
**Replies:** 9\
**Last updated:** [February 19, 2025, 4:32pm UTC](https://discourse.julialang.org/t/multiobjectivealgorithms-jl-skipping-infeasible-solutions/126003 "2025-02-19T16:32:16Z")

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Hi, I am using MultiObjectiveAlgorithms.jl with EpsilonConstraint method. When a small number of SolutionLimit is used, it went well and pareto front could be obtained. But, when I increase SolutionLimit to higher value…

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## [Abnormal behaviour when using callback two times in the same script](https://discourse.julialang.org/t/abnormal-behaviour-when-using-callback-two-times-in-the-same-script/126062)

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**Author:** [@Sushrut\_Deshpande](https://discourse.julialang.org/u/Sushrut_Deshpande)\
**Replies:** 1\
**Last updated:** [February 19, 2025, 12:05pm UTC](https://discourse.julialang.org/t/abnormal-behaviour-when-using-callback-two-times-in-the-same-script/126062 "2025-02-19T12:05:02Z")

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Hello, I have a MWE here for when I solve a ODE with callback two times in the same script , it solves the first one case expected and does not for the second one. using DifferentialEquations, Plots, OrdinaryDiffEq f…

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## [Differentiating through non-negative least squares solver?](https://discourse.julialang.org/t/differentiating-through-non-negative-least-squares-solver/125641)

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**Author:** [@ElOceanografo](https://discourse.julialang.org/u/ElOceanografo)\
**Replies:** 9\
**Last updated:** [February 19, 2025, 10:55am UTC](https://discourse.julialang.org/t/differentiating-through-non-negative-least-squares-solver/125641 "2025-02-19T10:55:18Z")

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Hi, I’m wondering if there’s a better way to get the gradient of a function like this one: using NonNegLeastSquares, DifferentiationInterface import FiniteDiff function f(aa, b) A = reshape(aa, size(b, 1), :) x…

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