# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=28

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**Page:** 29

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## [State of DCP (Disciplined Convex Programming)](https://discourse.julialang.org/t/state-of-dcp-disciplined-convex-programming/131743)

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**Author:** [@langestefan](https://discourse.julialang.org/u/langestefan)\
**Replies:** 17\
**Last updated:** [August 27, 2025, 12:25pm UTC](https://discourse.julialang.org/t/state-of-dcp-disciplined-convex-programming/131743 "2025-08-27T12:25:23Z")

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Lately I have been switching back between CVXPY and JuMP.jl a lot (mainly for work). One of the many nice features CVXPY has, is that it can automatically reformulate problems which are DCP-compliant through reductions.…

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## [Is there a way to have heatmap and contours from other variables in Plots.jl with GR?](https://discourse.julialang.org/t/is-there-a-way-to-have-heatmap-and-contours-from-other-variables-in-plots-jl-with-gr/131869)

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**Author:** [@PeX](https://discourse.julialang.org/u/PeX)\
**Replies:** 2\
**Last updated:** [August 27, 2025, 11:59am UTC](https://discourse.julialang.org/t/is-there-a-way-to-have-heatmap-and-contours-from-other-variables-in-plots-jl-with-gr/131869 "2025-08-27T11:59:18Z")

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Hi all! I’m trying to plot a heat map of one variable (with all values \>\>0), but on the same plot, I want to plot contours of two other variables where they equal 0. When I try countour! after plotting the heatmap, the…

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## [Suggestions for workshop demos?](https://discourse.julialang.org/t/suggestions-for-workshop-demos/131870)

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**Author:** [@JeffreySarnoff](https://discourse.julialang.org/u/JeffreySarnoff)\
**Replies:** 1\
**Last updated:** [August 27, 2025, 12:58am UTC](https://discourse.julialang.org/t/suggestions-for-workshop-demos/131870 "2025-08-27T00:58:45Z")

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I am planning a 2hr session showing compelling demonstrations of Julia to people who are experienced with some other languages \[there will first be 1/2 hr intro to Julia\] and have a professional/academic interest in adva…

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## [Show solver steps in Symbolics.jl](https://discourse.julialang.org/t/show-solver-steps-in-symbolics-jl/131851)

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**Author:** [@HiramTheHero](https://discourse.julialang.org/u/HiramTheHero)\
**Replies:** 2\
**Last updated:** [August 26, 2025, 8:06am UTC](https://discourse.julialang.org/t/show-solver-steps-in-symbolics-jl/131851 "2025-08-26T08:06:42Z")

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Sorry if is this is a repeat post. I couldn’t find anything in the Symbolics.jl docs nor in some cursory Google searching. I have the following code: using Symbolics, Nemo @variables r P K symbolic\_solve(0 ~ r \* P \* …

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## [Understanding GLMakie 3D meshscatter transparency/alpha](https://discourse.julialang.org/t/understanding-glmakie-3d-meshscatter-transparency-alpha/121414)

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**Author:** [@trahflow](https://discourse.julialang.org/u/trahflow)\
**Replies:** 4\
**Last updated:** [August 26, 2025, 2:15am UTC](https://discourse.julialang.org/t/understanding-glmakie-3d-meshscatter-transparency-alpha/121414 "2025-08-26T02:15:26Z")

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I’m trying to visualize a weighted 3D point set using meshscatter, where the weight is visualized using transparency: Low weight means high transparency. To do this I set a color alpha value for each point. The result …

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## [Broken permutation of axis in StatsPlots.jl with error bars](https://discourse.julialang.org/t/broken-permutation-of-axis-in-statsplots-jl-with-error-bars/131826)

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**Author:** [@LucasV](https://discourse.julialang.org/u/LucasV)\
**Replies:** 4\
**Last updated:** [August 25, 2025, 1:37pm UTC](https://discourse.julialang.org/t/broken-permutation-of-axis-in-statsplots-jl-with-error-bars/131826 "2025-08-25T13:37:58Z")

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Hi everyone, recently I’ve tried to plot a grouped bar using StatsPlots.jl with error bars. The plot works fine with no errors but when I insert them it does not work porperly, as shown in the example: Code: #Permutati…

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## [Forward Diff to cast Dual type to Float64](https://discourse.julialang.org/t/forward-diff-to-cast-dual-type-to-float64/131828)

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**Author:** [@Kate](https://discourse.julialang.org/u/Kate)\
**Replies:** 2\
**Last updated:** [August 25, 2025, 9:49am UTC](https://discourse.julialang.org/t/forward-diff-to-cast-dual-type-to-float64/131828 "2025-08-25T09:49:05Z")

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Hello, I’m a complete beginner to Julia. I’m currently using ForwardDiff to compute the Jacobian matrix of a vector-valued function, and that works very well. Now, I want to continue using ForwardDiff to compute ∂JAC/∂τ\[…

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## [Warnings when using logpdf of NoncentralT](https://discourse.julialang.org/t/warnings-when-using-logpdf-of-noncentralt/131815)

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**Author:** [@Transfrogirl](https://discourse.julialang.org/u/Transfrogirl)\
**Replies:** 0\
**Last updated:** [August 24, 2025, 8:29pm UTC](https://discourse.julialang.org/t/warnings-when-using-logpdf-of-noncentralt/131815 "2025-08-24T20:29:27Z")

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logpdf(NoncentralT(v, u), x) leads to warnings «full precision may not have been achieved in ‘pnt{final}’ ». as far as abs(u)\<40 On Linux, at least

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## [How to make a series optional in AlgebraOfGraphics.jl](https://discourse.julialang.org/t/how-to-make-a-series-optional-in-algebraofgraphics-jl/131798)

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**Author:** [@Abhro](https://discourse.julialang.org/u/Abhro)\
**Replies:** 2\
**Last updated:** [August 24, 2025, 9:23am UTC](https://discourse.julialang.org/t/how-to-make-a-series-optional-in-algebraofgraphics-jl/131798 "2025-08-24T09:23:10Z")

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I have a “wide” DataFrame where one column is a shared vector of x-values, and two different columns are separate vectors of y-values. For example, df = let t = range(0, 9, length = 1000) mass\_lab\_frame = @. cos…

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## [MTK - solve: weird error message](https://discourse.julialang.org/t/mtk-solve-weird-error-message/131638)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 7\
**Last updated:** [August 24, 2025, 7:28am UTC](https://discourse.julialang.org/t/mtk-solve-weird-error-message/131638 "2025-08-24T07:28:05Z")

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I’m on Julia v1.11.6 on Windows 11 64bit, using MTK v10.19.0, OrdinaryDiffEq v6.101.0. I try to use Clapeyron v0.6.15 with the code. My code worked without a flaw (except some warnings related to arrays and Clapeyron) i…

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## [How to use Autodiff in Gridap.jl](https://discourse.julialang.org/t/how-to-use-autodiff-in-gridap-jl/131652)

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**Author:** [@Sigmund](https://discourse.julialang.org/u/Sigmund)\
**Replies:** 4\
**Last updated:** [August 23, 2025, 5:45pm UTC](https://discourse.julialang.org/t/how-to-use-autodiff-in-gridap-jl/131652 "2025-08-23T17:45:57Z")

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TLDR: I want to solve an optimal control problem using automatic differentiation (Gridap uses ForwardDiff.jl), but i get an error when i try to find the gradient of the objective function. The objective function depends …

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## [cuSOLVER: two calls to cusolverDnDgesvdj\_bufferSize, one via Juila, the other via CUDA yield (very) different results](https://discourse.julialang.org/t/cusolver-two-calls-to-cusolverdndgesvdj-buffersize-one-via-juila-the-other-via-cuda-yield-very-different-results/125904)

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**Author:** [@FHulsemann](https://discourse.julialang.org/u/FHulsemann)\
**Replies:** 2\
**Last updated:** [August 22, 2025, 5:09pm UTC](https://discourse.julialang.org/t/cusolver-two-calls-to-cusolverdndgesvdj-buffersize-one-via-juila-the-other-via-cuda-yield-very-different-results/125904 "2025-08-22T17:09:21Z")

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Hello. I was wondering whether someone could explain to me why the working space for an SVD (gesvdj to be precise) differs wildly between a call to cusolverDnDgesvdj\_bufferSize via the Julia interface and a call via CU…

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## [3D isosurface plotting in Makie](https://discourse.julialang.org/t/3d-isosurface-plotting-in-makie/131470)

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**Author:** [@mreichMPI-BGC](https://discourse.julialang.org/u/mreichMPI-BGC)\
**Replies:** 14\
**Last updated:** [August 22, 2025, 2:38pm UTC](https://discourse.julialang.org/t/3d-isosurface-plotting-in-makie/131470 "2025-08-22T14:38:11Z")

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I am using the (semi-)documented contour function for 3D-isosurfaces, cf. volume | Makie, first example. One cannot define vector of alphas (which would be nice because outer surfaces (shells) “should” be more transpare…

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## [Putting non linear optimization in a real-time closed-loop](https://discourse.julialang.org/t/putting-non-linear-optimization-in-a-real-time-closed-loop/131753)

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**Author:** [@daro.slai](https://discourse.julialang.org/u/daro.slai)\
**Replies:** 1\
**Last updated:** [August 21, 2025, 6:20pm UTC](https://discourse.julialang.org/t/putting-non-linear-optimization-in-a-real-time-closed-loop/131753 "2025-08-21T18:20:35Z")

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Hi, I’m trying to implement an Energy Management Algorithm (QCP) I built using InfiniteOpt.jl. The algo gets measurements from a WebSocket connection. My main scripting function goes as: function oneStepOpt\_test1(set…

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## [Catalyst.jl - what's the best way to extract interpolation from the reaction\_network](https://discourse.julialang.org/t/catalyst-jl-whats-the-best-way-to-extract-interpolation-from-the-reaction-network/130171)

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**Author:** [@Mindy](https://discourse.julialang.org/u/Mindy)\
**Replies:** 7\
**Last updated:** [August 21, 2025, 3:22pm UTC](https://discourse.julialang.org/t/catalyst-jl-whats-the-best-way-to-extract-interpolation-from-the-reaction-network/130171 "2025-08-21T15:22:11Z")

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Hi! If I want to extract and plot the interpolating variable - $d\_rate (temporal dynamic profile) from this example code, does catalyst.jl have any built-in function so that I can extract the results directly, instead o…

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## [What is the correct way to use multiple GPUs in Slurm cluster?](https://discourse.julialang.org/t/what-is-the-correct-way-to-use-multiple-gpus-in-slurm-cluster/131740)

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**Author:** [@ytdHuang](https://discourse.julialang.org/u/ytdHuang)\
**Replies:** 0\
**Last updated:** [August 20, 2025, 3:52pm UTC](https://discourse.julialang.org/t/what-is-the-correct-way-to-use-multiple-gpus-in-slurm-cluster/131740 "2025-08-20T15:52:11Z")

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Hello Julia community, I am trying to distribute my computation using multiple GPUs in Slurm cluster. The code can be executed correctly while I’m using single GPU board in Slurm. However, when I try to use more than on…

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## [Stereonet diagram](https://discourse.julialang.org/t/stereonet-diagram/73121)

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**Author:** [@Gravlax](https://discourse.julialang.org/u/Gravlax)\
**Replies:** 13\
**Last updated:** [August 20, 2025, 12:49pm UTC](https://discourse.julialang.org/t/stereonet-diagram/73121 "2025-08-20T12:49:14Z")

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Dear all, I was wondering if any of you have came across a package that could be use for making stereonets (stereographic projections on a Wulff/Schmidt nets), e.g.: I’ve not found any examples of such diagram constr…

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## [Viz!( ) Color mapping on many grids](https://discourse.julialang.org/t/viz-color-mapping-on-many-grids/131423)

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**Author:** [@raman\_kumar](https://discourse.julialang.org/u/raman_kumar)\
**Replies:** 4\
**Last updated:** [August 11, 2025, 11:28pm UTC](https://discourse.julialang.org/t/viz-color-mapping-on-many-grids/131423 "2025-08-11T23:28:04Z")

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I am using Meshes.jl to create a polar coordinate grid. I have different grids with different r, ϕ and nrho values. I see that there color mapping is done for each grid individually. There is repetition of colors for eve…

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## [ODE solver takes 10x more steps without tstops](https://discourse.julialang.org/t/ode-solver-takes-10x-more-steps-without-tstops/131682)

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**Author:** [@mleseach](https://discourse.julialang.org/u/mleseach)\
**Replies:** 2\
**Last updated:** [August 19, 2025, 10:28am UTC](https://discourse.julialang.org/t/ode-solver-takes-10x-more-steps-without-tstops/131682 "2025-08-19T10:28:21Z")

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Hi everyone, I’m experiencing what seems like counterintuitive performance behavior with RDPK3Sp35() and I’m wondering if this is expected or worth investigating as a potential bug. I’m solving the same ODE with RDPK3…

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## [Trying to parallelize using CUSOLVERRF.jl with @threads](https://discourse.julialang.org/t/trying-to-parallelize-using-cusolverrf-jl-with-threads/131457)

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**Author:** [@mhunke](https://discourse.julialang.org/u/mhunke)\
**Replies:** 7\
**Last updated:** [August 19, 2025, 9:09am UTC](https://discourse.julialang.org/t/trying-to-parallelize-using-cusolverrf-jl-with-threads/131457 "2025-08-19T09:09:29Z")

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Hi everyone, I’m working with CUSOLVERRF.jl to solve multiple sparse linear systems on the GPU, using the high-level RFLU API: GitHub - exanauts/CUSOLVERRF.jl: A Julia wrapper for cusolverRF All systems share the same …

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## [NonlinearSolve.jl: Possible to store solution in-place of initial guess?](https://discourse.julialang.org/t/nonlinearsolve-jl-possible-to-store-solution-in-place-of-initial-guess/131208)

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**Author:** [@DanDoe](https://discourse.julialang.org/u/DanDoe)\
**Replies:** 16\
**Last updated:** [August 19, 2025, 7:23am UTC](https://discourse.julialang.org/t/nonlinearsolve-jl-possible-to-store-solution-in-place-of-initial-guess/131208 "2025-08-19T07:23:49Z")

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The standard workfllow to access the solution of a nonlinear\_eq = NonlinearProblem is something like sol = SciMLBase.solve(nonlinear\_eq, NewtonRaphson(autodiff = AutoFiniteDiff())); Is it possible to suppress the build…

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## [Optimisation over grid of parameters with \`Optimization.jl\`](https://discourse.julialang.org/t/optimisation-over-grid-of-parameters-with-optimization-jl/131571)

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**Author:** [@NoFishLikeIan](https://discourse.julialang.org/u/NoFishLikeIan)\
**Replies:** 7\
**Last updated:** [August 18, 2025, 10:28pm UTC](https://discourse.julialang.org/t/optimisation-over-grid-of-parameters-with-optimization-jl/131571 "2025-08-18T22:28:49Z")

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I am trying to solve a low dimensional (box-)constrained optimisation problem over a large grid of parameters. Both the optimisation problem and the constraints depend on the parameters. I can assume that the optimisatio…

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## [libTracyClient Bad Image Popup](https://discourse.julialang.org/t/libtracyclient-bad-image-popup/131691)

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**Author:** [@Jake](https://discourse.julialang.org/u/Jake)\
**Replies:** 0\
**Last updated:** [August 18, 2025, 7:16pm UTC](https://discourse.julialang.org/t/libtracyclient-bad-image-popup/131691 "2025-08-18T19:16:17Z")

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I was going through some tutorials on SciML.ai website and for the second tutorial when I tried \] add DifferentialEquations I get a julia.exe - Bad Image popup. It says “C:.…julia\\artifacts\\f91…\\bin\\libTractClient.dll …

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## [Solving a Shifted Linear System of 2 Symmetric Positive Semi Definite (SPSD) Matrices](https://discourse.julialang.org/t/solving-a-shifted-linear-system-of-2-symmetric-positive-semi-definite-spsd-matrices/131636)

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**Author:** [@RoyiAvital](https://discourse.julialang.org/u/RoyiAvital)\
**Replies:** 31\
**Last updated:** [August 18, 2025, 6:20pm UTC](https://discourse.julialang.org/t/solving-a-shifted-linear-system-of-2-symmetric-positive-semi-definite-spsd-matrices/131636 "2025-08-18T18:20:18Z")

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I have the following linear system: \\left( \\boldsymbol{A} + \\lambda \\boldsymbol{C} \\right) \\boldsymbol{x} = \\boldsymbol{A}^{T} \\boldsymbol{b} Where \\boldsymbol{A}, \\boldsymbol{C} \\in \\mathcal{S}\_{+}^{n} are Symmetric …

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## [Obtain the prior distribution for a function's parameter](https://discourse.julialang.org/t/obtain-the-prior-distribution-for-a-functions-parameter/131677)

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**Author:** [@Cyan](https://discourse.julialang.org/u/Cyan)\
**Replies:** 3\
**Last updated:** [August 18, 2025, 5:50pm UTC](https://discourse.julialang.org/t/obtain-the-prior-distribution-for-a-functions-parameter/131677 "2025-08-18T17:50:23Z")

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Hi, all. I met a problem getting the prior distribution for parameters in a function f(x; b, s, q). I wish to obtain a dict ParaDict = Dict(:b =\> b, :s =\> s, :q =\> q) in form of b ~ truncated(Normal(1., 1), 0, 5) s ~ t…

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## [Strange dependence on domain for polar coordinates in optimization over disk](https://discourse.julialang.org/t/strange-dependence-on-domain-for-polar-coordinates-in-optimization-over-disk/131676)

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**Author:** [@JADekker](https://discourse.julialang.org/u/JADekker)\
**Replies:** 4\
**Last updated:** [August 18, 2025, 4:20pm UTC](https://discourse.julialang.org/t/strange-dependence-on-domain-for-polar-coordinates-in-optimization-over-disk/131676 "2025-08-18T16:20:19Z")

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Hi, I’m trying to optimize a function over a disk using a transformation to polar coordinates. When I restrict the radius to non-negative values, there is no problem, but when I allow it to be negative, I get that the al…

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## [Complex Piecewise function](https://discourse.julialang.org/t/complex-piecewise-function/131681)

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**Author:** [@Sergey\_Novak](https://discourse.julialang.org/u/Sergey_Novak)\
**Replies:** 1\
**Last updated:** [August 18, 2025, 3:48pm UTC](https://discourse.julialang.org/t/complex-piecewise-function/131681 "2025-08-18T15:48:06Z")

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Hello, Can I add this function using Symbolics.jl? I know about ifelse, but I haven’t found any examples with multiple conditions. Thanks for your help

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## [Bilinear Model in Turing](https://discourse.julialang.org/t/bilinear-model-in-turing/131614)

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**Author:** [@hdubey](https://discourse.julialang.org/u/hdubey)\
**Replies:** 2\
**Last updated:** [August 18, 2025, 3:23pm UTC](https://discourse.julialang.org/t/bilinear-model-in-turing/131614 "2025-08-18T15:23:02Z")

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Hello, I am new to Julia and I am running Bayesian inference in Turing for a Bilinear Model- Y = X \* B \* Z’ + E where Y is nxm, X is nxp, B is pxq and Z is mxq. E is also nxm and follows multivariate normal (0, Sigma)…

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## [LDLt factorization for full matrices](https://discourse.julialang.org/t/ldlt-factorization-for-full-matrices/75356)

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**Author:** [@mancolric](https://discourse.julialang.org/u/mancolric)\
**Replies:** 27\
**Last updated:** [August 18, 2025, 10:16am UTC](https://discourse.julialang.org/t/ldlt-factorization-for-full-matrices/75356 "2025-08-18T10:16:10Z")

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Is there a way to compute the LDL^T factorization of a full matrix?? It seems that currently ldlt and LDLt support only SymTridiagonal and SparseMatrixCSC. However, lu works for full matrices. For example, using Linear…

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## [How to notify JuliaMath of a PR to one of their (almost) unwatched packages](https://discourse.julialang.org/t/how-to-notify-juliamath-of-a-pr-to-one-of-their-almost-unwatched-packages/131655)

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**Author:** [@PeterSimon](https://discourse.julialang.org/u/PeterSimon)\
**Replies:** 4\
**Last updated:** [August 18, 2025, 7:41am UTC](https://discourse.julialang.org/t/how-to-notify-juliamath-of-a-pr-to-one-of-their-almost-unwatched-packages/131655 "2025-08-18T07:41:23Z")

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I recently submitted a PR to FunctionZeros.jl to implement new functionality I need for a package I’m developing. FunctionZeros.jl is in the JuliaMath organization, and I’m not sure of the proper protocol, if any, to not…

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