# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=75

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**Page:** 76

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## [Why is FITSIO slow compared with python astropy?](https://discourse.julialang.org/t/why-is-fitsio-slow-compared-with-python-astropy/121926)

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**Author:** [@thevalentino](https://discourse.julialang.org/u/thevalentino)\
**Replies:** 4\
**Last updated:** [November 2, 2024, 7:04pm UTC](https://discourse.julialang.org/t/why-is-fitsio-slow-compared-with-python-astropy/121926 "2024-11-02T19:04:34Z")

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Hi there, I’m new to Julia and I’m trying to incorporate it to my work. I am trying to work with a FITS table that is fairly big (1.8 Gb). In astropy it’s easy to read it and load it into a pandas dataframe, it takes ~1…

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## [Sparse LU factorization on GPU](https://discourse.julialang.org/t/sparse-lu-factorization-on-gpu/122012)

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**Author:** [@IvanBioli](https://discourse.julialang.org/u/IvanBioli)\
**Replies:** 12\
**Last updated:** [November 2, 2024, 5:26pm UTC](https://discourse.julialang.org/t/sparse-lu-factorization-on-gpu/122012 "2024-11-02T17:26:39Z")

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Hi, I am working with a CuSparseMatrixCSR{Float64, Int32} matrix A on the GPU to solve a linear system multiple times during the training of an ML model. I’m hoping to perform a sparse LU factorization (with optional re…

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## [Storing the LU decomposition of a matrix](https://discourse.julialang.org/t/storing-the-lu-decomposition-of-a-matrix/122138)

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**Author:** [@Gattu\_Mytraya](https://discourse.julialang.org/u/Gattu_Mytraya)\
**Replies:** 5\
**Last updated:** [November 1, 2024, 7:57pm UTC](https://discourse.julialang.org/t/storing-the-lu-decomposition-of-a-matrix/122138 "2024-11-01T19:57:46Z")

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Hi! I have a calculation in which I need the determinant and possibly the inverse of a matrix (let’s call it X). I am, therefore, trying to store the LU decomposition of X and then use it later. To this end, I have the …

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## [Impossible to perform autodiff on simple ODE](https://discourse.julialang.org/t/impossible-to-perform-autodiff-on-simple-ode/120861)

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**Author:** [@albertomercurio](https://discourse.julialang.org/u/albertomercurio)\
**Replies:** 22\
**Last updated:** [November 1, 2024, 10:47am UTC](https://discourse.julialang.org/t/impossible-to-perform-autodiff-on-simple-ode/120861 "2024-11-01T10:47:16Z")

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Hello, I was trying to differentiate a simple ODE using Zygote.jl, but it returns the following error: ERROR: \`p\` is not a SciMLStructure. This is required for adjoint sensitivity analysis. For more information, see th…

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## [Reusing a JuMP \`Model\` for several, different optimization problems](https://discourse.julialang.org/t/reusing-a-jump-model-for-several-different-optimization-problems/122031)

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**Author:** [@tchr](https://discourse.julialang.org/u/tchr)\
**Replies:** 9\
**Last updated:** [November 1, 2024, 10:29am UTC](https://discourse.julialang.org/t/reusing-a-jump-model-for-several-different-optimization-problems/122031 "2024-11-01T10:29:53Z")

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I am using JuMP to solve many (~tens to hundreds of thousands) small integer-feasibility problems (variants of a subset sum problem). Each individual problem is parameterized by different integers but the structure is qu…

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## [Real-time input and plotting with ModelingToolkit](https://discourse.julialang.org/t/real-time-input-and-plotting-with-modelingtoolkit/120713)

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**Author:** [@cstjean](https://discourse.julialang.org/u/cstjean)\
**Replies:** 9\
**Last updated:** [November 1, 2024, 8:37am UTC](https://discourse.julialang.org/t/real-time-input-and-plotting-with-modelingtoolkit/120713 "2024-11-01T08:37:00Z")

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I’d like to have an MTK model like D(x) = k\*x, and plot the solution in real time (after 1 second, the plot shows the solution from t=0 to t=1, etc.) I’d like k to be supplied by a real-time interactive slider (so that …

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## [Performance gains from using ParametricOptInterface.jl vs variables](https://discourse.julialang.org/t/performance-gains-from-using-parametricoptinterface-jl-vs-variables/121762)

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**Author:** [@nealhughes](https://discourse.julialang.org/u/nealhughes)\
**Replies:** 7\
**Last updated:** [November 1, 2024, 6:27am UTC](https://discourse.julialang.org/t/performance-gains-from-using-parametricoptinterface-jl-vs-variables/121762 "2024-11-01T06:27:48Z")

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I have a model coded in JuMP which needs to be solved multiple times in a loop. It is an inter-temporal / rolling horizon problem where the model is solved for one time period at a time, then various “parameters” need to…

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## [Failed to precompile Gurobi](https://discourse.julialang.org/t/failed-to-precompile-gurobi/122069)

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**Author:** [@Y\_Naruse](https://discourse.julialang.org/u/Y_Naruse)\
**Replies:** 4\
**Last updated:** [November 1, 2024, 2:29am UTC](https://discourse.julialang.org/t/failed-to-precompile-gurobi/122069 "2024-11-01T02:29:53Z")

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I want to use Gurobi on Julia. When I try to add Gurobi like this, it fails. julia\> import Pkg julia\> Pkg.add("Gurobi") Resolving package versions... No Changes to \`C:\\Users\\N185062\\.julia\\environments\\v1.11\\Proje…

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## [Help with NUFFT (NFFT) vs FFT in Radial MRI applications](https://discourse.julialang.org/t/help-with-nufft-nfft-vs-fft-in-radial-mri-applications/122106)

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**Author:** [@matividalg](https://discourse.julialang.org/u/matividalg)\
**Replies:** 0\
**Last updated:** [November 1, 2024, 12:52am UTC](https://discourse.julialang.org/t/help-with-nufft-nfft-vs-fft-in-radial-mri-applications/122106 "2024-11-01T00:52:02Z")

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Hi there! I have a few problems when generating a “fHat” matrix of a NFFT (using package NFFT) vs when dealing with the inverse fft of my own (imperfect) adquisition. Let me illustrate. I’m simulating a regular Gradient…

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## [Tooling for inference and simulation on temporal point processes?](https://discourse.julialang.org/t/tooling-for-inference-and-simulation-on-temporal-point-processes/121885)

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**Author:** [@slwu89](https://discourse.julialang.org/u/slwu89)\
**Replies:** 0\
**Last updated:** [October 28, 2024, 5:08pm UTC](https://discourse.julialang.org/t/tooling-for-inference-and-simulation-on-temporal-point-processes/121885 "2024-10-28T17:08:27Z")

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Hi all, I’m looking for advice (statistical and computational) to do something like the following simulation/inference for nonhomogeneous point processes (temporal, not considering space): Specify a “prior” for the in…

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## [Correct way of computing adjoints/gradients with dense solution of ODE](https://discourse.julialang.org/t/correct-way-of-computing-adjoints-gradients-with-dense-solution-of-ode/121964)

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**Author:** [@facusapienza](https://discourse.julialang.org/u/facusapienza)\
**Replies:** 5\
**Last updated:** [October 31, 2024, 6:17pm UTC](https://discourse.julialang.org/t/correct-way-of-computing-adjoints-gradients-with-dense-solution-of-ode/121964 "2024-10-31T18:17:18Z")

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Hi all, I am trying to use the interpolated solution of my ODE for adjoint sensitivity analysis. Since I have a very small system of ODEs (n=3), I am interested in evaluating the performance of continuous adjoint method…

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## [Can I use CuSpareMatrixCSC with Complex entries for ODE solving?](https://discourse.julialang.org/t/can-i-use-cusparematrixcsc-with-complex-entries-for-ode-solving/122080)

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**Author:** [@joseph-t-lee](https://discourse.julialang.org/u/joseph-t-lee)\
**Replies:** 1\
**Last updated:** [October 31, 2024, 6:02pm UTC](https://discourse.julialang.org/t/can-i-use-cusparematrixcsc-with-complex-entries-for-ode-solving/122080 "2024-10-31T18:02:47Z")

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(Apologies if this is confusing - this is my first post, and first time I haven’t been able to find my answer already on the forum!) I have been trying to rewrite some old CPU code that used Sparse Matrices with Complex…

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## [Slow JuMP model creation](https://discourse.julialang.org/t/slow-jump-model-creation/122005)

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**Author:** [@jakubp](https://discourse.julialang.org/u/jakubp)\
**Replies:** 3\
**Last updated:** [October 31, 2024, 5:52pm UTC](https://discourse.julialang.org/t/slow-jump-model-creation/122005 "2024-10-31T17:52:30Z")

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I am trying to solve a very large (N=100M variables) and very sparse (density ~ 1/N) QUBO problem, using CPLEX interfaced via JuMP. To this end, I’m using the following function function solve\_with\_CPLEX(Q) L = size(…

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## [CairoMakie - Controlling radial axes in polar plots](https://discourse.julialang.org/t/cairomakie-controlling-radial-axes-in-polar-plots/122008)

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**Author:** [@togo59](https://discourse.julialang.org/u/togo59)\
**Replies:** 3\
**Last updated:** [October 31, 2024, 5:37pm UTC](https://discourse.julialang.org/t/cairomakie-controlling-radial-axes-in-polar-plots/122008 "2024-10-31T17:37:42Z")

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I can’t quite fathom the logic CM uses for the radial axes interval for polar plots. The default seems to be 45 degrees, but if (say) the thetalimits = (-pi/6 to +pi/6), the axes are at 10 degree intervals. In the docume…

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## [Change mesh color in Plots.jl?](https://discourse.julialang.org/t/change-mesh-color-in-plots-jl/76625)

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**Author:** [@BambOoxX](https://discourse.julialang.org/u/BambOoxX)\
**Replies:** 5\
**Last updated:** [October 31, 2024, 5:10pm UTC](https://discourse.julialang.org/t/change-mesh-color-in-plots-jl/76625 "2024-10-31T17:10:13Z")

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I am trying to get a hold on Plots.jl capability to plot meshes. The mesh3d seems to be the good choice for that. With the following example, I manage to plot a uniformly colored mesh with the plotlyjs backed. using Pl…

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## [Understanding Neural Networks (and Lux)](https://discourse.julialang.org/t/understanding-neural-networks-and-lux/122073)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 3\
**Last updated:** [October 31, 2024, 2:52pm UTC](https://discourse.julialang.org/t/understanding-neural-networks-and-lux/122073 "2024-10-31T14:52:38Z")

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0. Overview I’m trying to understand neural networks and Lux in particular, and how it is related to interpolation and least squares regression. So this post is more on fundamental understanding than Lux-technicalities. …

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## [Large scale model using Gurobi causes machine crushed](https://discourse.julialang.org/t/large-scale-model-using-gurobi-causes-machine-crushed/121988)

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**Author:** [@Betristor](https://discourse.julialang.org/u/Betristor)\
**Replies:** 11\
**Last updated:** [October 31, 2024, 2:40am UTC](https://discourse.julialang.org/t/large-scale-model-using-gurobi-causes-machine-crushed/121988 "2024-10-31T02:40:50Z")

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For the record, I still have not found the reason why my server crushed solving some large models using JuMP+Gurobi. But I have experienced like dozens of times. Here is the situation. Each time I constructed a JuMP mod…

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## [Bizarre behaviour of WGLMakie](https://discourse.julialang.org/t/bizarre-behaviour-of-wglmakie/122021)

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**Author:** [@adhalanay](https://discourse.julialang.org/u/adhalanay)\
**Replies:** 0\
**Last updated:** [October 30, 2024, 9:43pm UTC](https://discourse.julialang.org/t/bizarre-behaviour-of-wglmakie/122021 "2024-10-30T21:43:52Z")

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I am trying to create an interactive plot to be shown in jupyterlab. The content of the cell is using WGLMakie using Bonito x0=0.01 fig=Figure() ax=Axis(fig\[1,1\]) slr=WGLMakie.SliderGrid(fig\[2, 1\], (label="r",rang…

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## [Reformulating Logarithmic Objective Function for Gurobi in Julia with JuMP](https://discourse.julialang.org/t/reformulating-logarithmic-objective-function-for-gurobi-in-julia-with-jump/121961)

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**Author:** [@Beyza\_Aydin](https://discourse.julialang.org/u/Beyza_Aydin)\
**Replies:** 3\
**Last updated:** [October 30, 2024, 8:25pm UTC](https://discourse.julialang.org/t/reformulating-logarithmic-objective-function-for-gurobi-in-julia-with-jump/121961 "2024-10-30T20:25:20Z")

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Hi, I’m working on an optimization problem in Julia where I need to maximize a logarithmic objective function (maximize sum of logs ): @objective(model, Max, sum(alp\[i\] \* log( p\[i\]) for i in 1:n)) where alp is vector…

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## [Odd warning and issues with optimization only when inside Optimization.jl. Zygote.hessian works fine](https://discourse.julialang.org/t/odd-warning-and-issues-with-optimization-only-when-inside-optimization-jl-zygote-hessian-works-fine/121967)

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**Author:** [@Hareruya](https://discourse.julialang.org/u/Hareruya)\
**Replies:** 8\
**Last updated:** [October 30, 2024, 7:39pm UTC](https://discourse.julialang.org/t/odd-warning-and-issues-with-optimization-only-when-inside-optimization-jl-zygote-hessian-works-fine/121967 "2024-10-30T19:39:55Z")

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Greetings, everyone. Apologies if the query is too basic, as it does not impede optimization in one case. I have graduated from my PhD program and have gotten a job at a company that offers me freedom in what programmin…

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## [Running CUDA.jl test results in my PC with Ubuntu 22.04 to freeze and become unresponsive\`](https://discourse.julialang.org/t/running-cuda-jl-test-results-in-my-pc-with-ubuntu-22-04-to-freeze-and-become-unresponsive/118434)

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**Author:** [@Mend-Amar\_Badral](https://discourse.julialang.org/u/Mend-Amar_Badral)\
**Replies:** 12\
**Last updated:** [October 30, 2024, 4:03pm UTC](https://discourse.julialang.org/t/running-cuda-jl-test-results-in-my-pc-with-ubuntu-22-04-to-freeze-and-become-unresponsive/118434 "2024-10-30T16:03:00Z")

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I have a PC that runs Ubuntu that has nvidia gpu(3080ti). I’ve installed CUDA.jl recently, and I believe pc has met all the requirements. It has Nvidia drivers installed. But when I enter pkg\> test CUDA There was an er…

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## [Makie Observable Bug](https://discourse.julialang.org/t/makie-observable-bug/121724)

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**Author:** [@Allan\_Baker](https://discourse.julialang.org/u/Allan_Baker)\
**Replies:** 4\
**Last updated:** [October 29, 2024, 9:27pm UTC](https://discourse.julialang.org/t/makie-observable-bug/121724 "2024-10-29T21:27:07Z")

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I can’t figure out how to squash this. I’ve never had this problem before when using Observables and Makie. What’s the secret. For a surface plot, when I update the x-vector and change its size, and update the Z vecto…

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## [Performing max-min optimization with optimization.jl](https://discourse.julialang.org/t/performing-max-min-optimization-with-optimization-jl/121991)

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**Author:** [@KianH](https://discourse.julialang.org/u/KianH)\
**Replies:** 0\
**Last updated:** [October 30, 2024, 12:36pm UTC](https://discourse.julialang.org/t/performing-max-min-optimization-with-optimization-jl/121991 "2024-10-30T12:36:01Z")

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Hello, I was wondering if it is possible to solve minimax optimization problems using Optimization.jl for neural networks? I am currently performing the optimization using Optimization.solve(...). I am specifically inte…

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## [Confusion in terminology dt & timing in agents.jl continuous time/EBM model](https://discourse.julialang.org/t/confusion-in-terminology-dt-timing-in-agents-jl-continuous-time-ebm-model/121748)

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**Author:** [@Sahil\_Khan](https://discourse.julialang.org/u/Sahil_Khan)\
**Replies:** 3\
**Last updated:** [October 30, 2024, 7:11am UTC](https://discourse.julialang.org/t/confusion-in-terminology-dt-timing-in-agents-jl-continuous-time-ebm-model/121748 "2024-10-30T07:11:34Z")

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Hello everyone, Im working with EBM continuous time model. Im little confused between dt given in model initiation function and timing term while defining events for model. It will be really helpful if someone can desc…

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## [How to perform practical identifiability in Julia?](https://discourse.julialang.org/t/how-to-perform-practical-identifiability-in-julia/121671)

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**Author:** [@Nick1](https://discourse.julialang.org/u/Nick1)\
**Replies:** 3\
**Last updated:** [October 30, 2024, 6:59am UTC](https://discourse.julialang.org/t/how-to-perform-practical-identifiability-in-julia/121671 "2024-10-30T06:59:20Z")

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Is there a way to perform practical identifiability in Julia? I have a systems biology problem with limited data and want to determine which parameters are practically identifiable.

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## [JuMP, moi wrapper, interface problem](https://discourse.julialang.org/t/jump-moi-wrapper-interface-problem/121776)

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**Author:** [@zhenweilin](https://discourse.julialang.org/u/zhenweilin)\
**Replies:** 8\
**Last updated:** [October 30, 2024, 3:11am UTC](https://discourse.julialang.org/t/jump-moi-wrapper-interface-problem/121776 "2024-10-30T03:11:55Z")

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JuMP, moi wrapper, interface problem. I am currently developing an SOCP solver designed to address the following optimization problem. min\_{x=(x\_1,x\_2),l \\leq x\_1 \\leq u, x\_2\\in\\mathcal{K}}c^\\top x \\text{ s.t.}Gx-h\\in …

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## [Scheduler errors when trying to graph agents](https://discourse.julialang.org/t/scheduler-errors-when-trying-to-graph-agents/121706)

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**Author:** [@tfranks](https://discourse.julialang.org/u/tfranks)\
**Replies:** 4\
**Last updated:** [October 29, 2024, 10:35pm UTC](https://discourse.julialang.org/t/scheduler-errors-when-trying-to-graph-agents/121706 "2024-10-29T22:35:05Z")

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Hello, I’ve created an agent-based model where depositor agents withdraw money from bank agents. I’m now trying to create a visual of the network by using Graphs.jl to show the banks as nodes and the depositors’ paths a…

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## [Sampling from custom distribution: "No method matching iterate..."](https://discourse.julialang.org/t/sampling-from-custom-distribution-no-method-matching-iterate/121925)

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**Author:** [@alexdmeyer](https://discourse.julialang.org/u/alexdmeyer)\
**Replies:** 5\
**Last updated:** [October 29, 2024, 10:24pm UTC](https://discourse.julialang.org/t/sampling-from-custom-distribution-no-method-matching-iterate/121925 "2024-10-29T22:24:10Z")

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Hello fellow Julians, I’m trying to use a custom distribution/sampleable for inference in Turing.jl, and I’ve encountered a problem I can’t solve. Following the instructions on the Turing docs, I made the following mini…

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## [Non-linear analysis](https://discourse.julialang.org/t/non-linear-analysis/121890)

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**Author:** [@SergeantMike67](https://discourse.julialang.org/u/SergeantMike67)\
**Replies:** 18\
**Last updated:** [October 29, 2024, 9:34pm UTC](https://discourse.julialang.org/t/non-linear-analysis/121890 "2024-10-29T21:34:30Z")

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Having a bit of an issue and I don’t quite know where to turn. I have insect emergence data that fits a Gompertz model quite well. Example Data Row │ ED Wasp │ Float64 Float64 ─────┼────────────────── 1 │ 14…

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## [Using a sparse Hessian in Optim.jl](https://discourse.julialang.org/t/using-a-sparse-hessian-in-optim-jl/121768)

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**Author:** [@rsenne](https://discourse.julialang.org/u/rsenne)\
**Replies:** 21\
**Last updated:** [October 29, 2024, 1:05pm UTC](https://discourse.julialang.org/t/using-a-sparse-hessian-in-optim-jl/121768 "2024-10-29T13:05:02Z")

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I’m currently trying to make code for a package I’m developing as performant as possible. One function I’m writing is to perform smoothing for a state-space model using a method advocated in this paper: where one uses…

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