# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=82

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**Page:** 83

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## [Convergence of inverse problem of heat equation with PINN](https://discourse.julialang.org/t/convergence-of-inverse-problem-of-heat-equation-with-pinn/119866)

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**Author:** [@AliaNajwaMY](https://discourse.julialang.org/u/AliaNajwaMY)\
**Replies:** 0\
**Last updated:** [September 25, 2024, 1:41pm UTC](https://discourse.julialang.org/t/convergence-of-inverse-problem-of-heat-equation-with-pinn/119866 "2024-09-25T13:41:49Z")

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I’m having trouble getting my inverse problem of heat equation with multiple parameters to converge using the neuromancer package (which encodes the PINN model). I am coding using python but was told that I still could a…

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## [Accessing remote server data locally for 3D plotting purposes](https://discourse.julialang.org/t/accessing-remote-server-data-locally-for-3d-plotting-purposes/119853)

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**Author:** [@Gavin\_Held](https://discourse.julialang.org/u/Gavin_Held)\
**Replies:** 2\
**Last updated:** [September 25, 2024, 11:35am UTC](https://discourse.julialang.org/t/accessing-remote-server-data-locally-for-3d-plotting-purposes/119853 "2024-09-25T11:35:50Z")

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Hello, I work with large simulation data, on the order of 100s GB- 1TB, through a remote server. The clusters on which I run and store data do not play well with GLMakie/3D plotting as the login nodes do not have a gpu…

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## [Is ModelingToolkit.getdefault deprecated?](https://discourse.julialang.org/t/is-modelingtoolkit-getdefault-deprecated/119748)

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**Author:** [@kraqbi](https://discourse.julialang.org/u/kraqbi)\
**Replies:** 3\
**Last updated:** [September 25, 2024, 10:59am UTC](https://discourse.julialang.org/t/is-modelingtoolkit-getdefault-deprecated/119748 "2024-09-25T10:59:25Z")

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Hello, In ModelingToolkit, I find it usefull to have a function to access the default values of parameters. It took me some times to find the function ModelingToolkit.getdefault() I could not find it in the tutorial a…

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## [Initial and final affect for timed periodic event in ModelingToolkeit](https://discourse.julialang.org/t/initial-and-final-affect-for-timed-periodic-event-in-modelingtoolkeit/119849)

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**Author:** [@jmaedler](https://discourse.julialang.org/u/jmaedler)\
**Replies:** 3\
**Last updated:** [September 25, 2024, 9:57am UTC](https://discourse.julialang.org/t/initial-and-final-affect-for-timed-periodic-event-in-modelingtoolkeit/119849 "2024-09-25T09:57:30Z")

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Hi everyone, I am working on an adapter for virtual commissioning using ModelingToolkit.jl. More specifically, I use discrete callbacks (timed → periodic) to read inputs from and write output to a soft-controller. Is th…

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## [Makie: how to plot/draw above axis splines?](https://discourse.julialang.org/t/makie-how-to-plot-draw-above-axis-splines/119850)

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**Author:** [@Datseris](https://discourse.julialang.org/u/Datseris)\
**Replies:** 1\
**Last updated:** [September 25, 2024, 9:14am UTC](https://discourse.julialang.org/t/makie-how-to-plot-draw-above-axis-splines/119850 "2024-09-25T09:14:06Z")

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I have this plot: the markers with white stroke are scatter! plot. How do I make them plot above the axis splines so that they are shown in full instead of being cut out by the axis? The keyword overdraw = true does…

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## [Known disturbances in JuliaSimControl MPC](https://discourse.julialang.org/t/known-disturbances-in-juliasimcontrol-mpc/119810)

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**Author:** [@bertrand](https://discourse.julialang.org/u/bertrand)\
**Replies:** 3\
**Last updated:** [September 25, 2024, 8:00am UTC](https://discourse.julialang.org/t/known-disturbances-in-juliasimcontrol-mpc/119810 "2024-09-25T08:00:49Z")

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Hi, I’m writing an MPC with known external disturbances using JuliaSimControl. I’m currently passing the known disturbances w as part of the parameter vector into the dynamics function, i.e. function dynamics(x, u, p,…

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## [Performance issues with Turing and NUTS](https://discourse.julialang.org/t/performance-issues-with-turing-and-nuts/119749)

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**Author:** [@Benjamin\_Zanger](https://discourse.julialang.org/u/Benjamin_Zanger)\
**Replies:** 4\
**Last updated:** [September 24, 2024, 10:08pm UTC](https://discourse.julialang.org/t/performance-issues-with-turing-and-nuts/119749 "2024-09-24T22:08:16Z")

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Hello, I am new to Turing and try to do MCMC sampling from a simple linear forward model with gaussian prior. I got the following model: A = randn(20, 1000) m = size(A, 1) n = size(A, 2) x\_true = randn(n) σ\_prior = 0…

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## [How to loop through all the species and write additional reactions based on that](https://discourse.julialang.org/t/how-to-loop-through-all-the-species-and-write-additional-reactions-based-on-that/115438)

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**Author:** [@Wenzhe\_Ma](https://discourse.julialang.org/u/Wenzhe_Ma)\
**Replies:** 2\
**Last updated:** [September 24, 2024, 7:52pm UTC](https://discourse.julialang.org/t/how-to-loop-through-all-the-species-and-write-additional-reactions-based-on-that/115438 "2024-09-24T19:52:15Z")

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What I want to do is to build a few models based on ReactionSystem in Catalyst.jl, named as m1, m2… Each of them has some common species s1, s2… I want to have a function with m1, m2 as arguments, which will automaticall…

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## [Multipage Stipple webapp](https://discourse.julialang.org/t/multipage-stipple-webapp/67852)

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**Author:** [@julien\_goo](https://discourse.julialang.org/u/julien_goo)\
**Replies:** 9\
**Last updated:** [September 24, 2024, 3:58pm UTC](https://discourse.julialang.org/t/multipage-stipple-webapp/67852 "2024-09-24T15:58:32Z")

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Hi all, Is it possible to have multipage apps based on Stipple? Not necessarily with different url, but with a clickable menu just like a Shinydashboard does with the R Shiny framework. I bet there is a strong interest…

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## [How to add a legend to a figure with only a \`(fig, ax)\` tuple in hand?](https://discourse.julialang.org/t/how-to-add-a-legend-to-a-figure-with-only-a-fig-ax-tuple-in-hand/119795)

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**Author:** [@WuSiren](https://discourse.julialang.org/u/WuSiren)\
**Replies:** 6\
**Last updated:** [September 24, 2024, 8:51am UTC](https://discourse.julialang.org/t/how-to-add-a-legend-to-a-figure-with-only-a-fig-ax-tuple-in-hand/119795 "2024-09-24T08:51:27Z")

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I only have a (fig, ax) tuple of a figure in hand. Now I want to add a legend for this figure. How can I do? julia\> fig, ax (Scene (600px, 450px): 0 Plots 1 Child Scene: └ Scene (600px, 450px), Axis (5 plots)) …

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## [ModelPredictiveControl.jl vs JuliaSimControl](https://discourse.julialang.org/t/modelpredictivecontrol-jl-vs-juliasimcontrol/119496)

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**Author:** [@Bart\_van\_de\_Lint](https://discourse.julialang.org/u/Bart_van_de_Lint)\
**Replies:** 10\
**Last updated:** [September 24, 2024, 6:52am UTC](https://discourse.julialang.org/t/modelpredictivecontrol-jl-vs-juliasimcontrol/119496 "2024-09-24T06:52:02Z")

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What would be the advantages / disadvantages of using ModelPredictiveControl.jl over JuliaSimControl? I am trying to decide which one to use, and these were the first two packages I found.

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## [PowerModels active and reactive power demand](https://discourse.julialang.org/t/powermodels-active-and-reactive-power-demand/119787)

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**Author:** [@Glon](https://discourse.julialang.org/u/Glon)\
**Replies:** 2\
**Last updated:** [September 24, 2024, 6:27am UTC](https://discourse.julialang.org/t/powermodels-active-and-reactive-power-demand/119787 "2024-09-24T06:27:14Z")

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Hello all, I am new to Julia and I am trying to run an acopf problem, but having trouble on how to loop it for a whole day. I have the active and reactive power demand at each bus for every 30 minutes. Below is the code…

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## [Considering water head in SDDP.jl](https://discourse.julialang.org/t/considering-water-head-in-sddp-jl/119779)

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**Author:** [@Sorooshsa](https://discourse.julialang.org/u/Sorooshsa)\
**Replies:** 1\
**Last updated:** [September 24, 2024, 3:34am UTC](https://discourse.julialang.org/t/considering-water-head-in-sddp-jl/119779 "2024-09-24T03:34:14Z")

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Hi everyone, I’m using SDDP.jl to model hydropower production and want to include the effect of water head in the production constraint, which is typically formulated as P = release×water head×efficiency parameter. He…

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## [Creating orthogonality constraints in JuMP](https://discourse.julialang.org/t/creating-orthogonality-constraints-in-jump/47462)

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**Author:** [@jbmuir](https://discourse.julialang.org/u/jbmuir)\
**Replies:** 3\
**Last updated:** [September 24, 2024, 3:14am UTC](https://discourse.julialang.org/t/creating-orthogonality-constraints-in-jump/47462 "2024-09-24T03:14:26Z")

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I’m trying to impose some orthogonality constraints for an optimal design problem in JuMP; since these are nonlinear vector constraints I believe that I have to use the @NLconstraint macro with splatting. I can’t quite f…

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## [Cholesky Decomposition of a Sparse Symmetric Positive Semidefinite (SPSD) Singular Matrix](https://discourse.julialang.org/t/cholesky-decomposition-of-a-sparse-symmetric-positive-semidefinite-spsd-singular-matrix/119682)

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**Author:** [@RoyiAvital](https://discourse.julialang.org/u/RoyiAvital)\
**Replies:** 19\
**Last updated:** [September 23, 2024, 5:31pm UTC](https://discourse.julialang.org/t/cholesky-decomposition-of-a-sparse-symmetric-positive-semidefinite-spsd-singular-matrix/119682 "2024-09-23T17:31:44Z")

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Is there such equivalent for sparse matrix? I don’t see the pivoting option for SparseMatrixCSC. How would you handle a Sparse SPSD matrix? Currently I just use check = false. Probably small shift should help but i…

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## [Multivariate Student's T distribution?](https://discourse.julialang.org/t/multivariate-students-t-distribution/119676)

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**Author:** [@rsenne](https://discourse.julialang.org/u/rsenne)\
**Replies:** 5\
**Last updated:** [September 23, 2024, 4:05pm UTC](https://discourse.julialang.org/t/multivariate-students-t-distribution/119676 "2024-09-23T16:05:47Z")

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Does there exist any active implementations of a multivariate Student’s T distribution? I need one for a model I am implementing but the only information I could find was from a multi year old issue on the Distributions.…

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## [CUDA performing scalar indexing when used along with Distributed](https://discourse.julialang.org/t/cuda-performing-scalar-indexing-when-used-along-with-distributed/119470)

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**Author:** [@Paulo\_Refosco](https://discourse.julialang.org/u/Paulo_Refosco)\
**Replies:** 5\
**Last updated:** [September 23, 2024, 3:28pm UTC](https://discourse.julialang.org/t/cuda-performing-scalar-indexing-when-used-along-with-distributed/119470 "2024-09-23T15:28:07Z")

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Hello all! I am running a series of nested functions, some of which using CUDA.jl at high level CuArrays processing (dot products and/or matrix multiplications). When I run it single threaded it works perfectly (even if…

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## [Next\_step! resulting in slightly different results for the same inputs](https://discourse.julialang.org/t/next-step-resulting-in-slightly-different-results-for-the-same-inputs/119683)

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**Author:** [@Bart\_van\_de\_Lint](https://discourse.julialang.org/u/Bart_van_de_Lint)\
**Replies:** 13\
**Last updated:** [September 23, 2024, 12:51pm UTC](https://discourse.julialang.org/t/next-step-resulting-in-slightly-different-results-for-the-same-inputs/119683 "2024-09-23T12:51:36Z")

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I am using the following code to initialize an MTK model: dt = 0.05 tspan = (0.0, dt) solver = CVODE\_BDF() integrator = OrdinaryDiffEqCore.init(prob, solver; dt, abstol=0.0006, reltol=0.001, save\_on=false, dtmin=1e-…

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## [Python mpfr floats to Julia BigFloat / mpfr](https://discourse.julialang.org/t/python-mpfr-floats-to-julia-bigfloat-mpfr/119724)

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**Author:** [@thedeyan](https://discourse.julialang.org/u/thedeyan)\
**Replies:** 1\
**Last updated:** [September 23, 2024, 7:06am UTC](https://discourse.julialang.org/t/python-mpfr-floats-to-julia-bigfloat-mpfr/119724 "2024-09-23T07:06:39Z")

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I have a numpy array of type object and filled with gmpy2.mpfr numbers: x = np.empty(3, dtype=object) x\[0\] = mpfr("0.4", 1000) x\[1\] = mpfr("0.6", 1000) x\[2\] = mpfr("0.8", 1000) and I have a function in Julia which oper…

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## [GPU slower than CPU for simple benchmarks](https://discourse.julialang.org/t/gpu-slower-than-cpu-for-simple-benchmarks/119687)

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**Author:** [@billmclean](https://discourse.julialang.org/u/billmclean)\
**Replies:** 7\
**Last updated:** [September 23, 2024, 6:50am UTC](https://discourse.julialang.org/t/gpu-slower-than-cpu-for-simple-benchmarks/119687 "2024-09-23T06:50:09Z")

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I recently updated the CPU on my desktop: julia\> versioninfo() Julia Version 1.10.5 Commit 6f3fdf7b362 (2024-08-27 14:19 UTC) Build Info: Official https://julialang.org/ release Platform Info: OS: Linux (x86\_64-linu…

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## [MTK... linearization of zero dynamics](https://discourse.julialang.org/t/mtk-linearization-of-zero-dynamics/119546)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 7\
**Last updated:** [September 23, 2024, 4:19am UTC](https://discourse.julialang.org/t/mtk-linearization-of-zero-dynamics/119546 "2024-09-23T04:19:50Z")

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\[What is the trick of hiding/folding/collapsing code blocks?\] Consider the well-known 4-tank model by K.H. Johansson: which has been designed to illustrate multivariable zero dynamics. The system has 2 control inputs…

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## [Conditional MH() proposals fail to accept (simplified question)](https://discourse.julialang.org/t/conditional-mh-proposals-fail-to-accept-simplified-question/119531)

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**Author:** [@aws](https://discourse.julialang.org/u/aws)\
**Replies:** 1\
**Last updated:** [September 22, 2024, 9:48pm UTC](https://discourse.julialang.org/t/conditional-mh-proposals-fail-to-accept-simplified-question/119531 "2024-09-22T21:48:48Z")

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Hello, I am attempting to perform Gibbs sampling using a mixture of close formed conditional posteriors and other samplers. Ultimately, I will use this to estimate parameters in a nonlinear model where I can write out t…

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## [Requiring a NamedTuple instead of just a tuple to return multiple columns from a function for DataFrames.jl seem unintuitive. Discussion](https://discourse.julialang.org/t/requiring-a-namedtuple-instead-of-just-a-tuple-to-return-multiple-columns-from-a-function-for-dataframes-jl-seem-unintuitive-discussion/119691)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 3\
**Last updated:** [September 22, 2024, 1:06pm UTC](https://discourse.julialang.org/t/requiring-a-namedtuple-instead-of-just-a-tuple-to-return-multiple-columns-from-a-function-for-dataframes-jl-seem-unintuitive-discussion/119691 "2024-09-22T13:06:28Z")

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I tried to read the transform doc for DataFrames.jl and I have to say it’s tough going. But I think it contains lots of info. The situation I want to discuss is actually documented in the doc but the question, how do I …

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## [Failing to import (relatively) large CSV file with Julia and VSC](https://discourse.julialang.org/t/failing-to-import-relatively-large-csv-file-with-julia-and-vsc/112350)

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**Author:** [@etiennebert](https://discourse.julialang.org/u/etiennebert)\
**Replies:** 24\
**Last updated:** [September 22, 2024, 12:53pm UTC](https://discourse.julialang.org/t/failing-to-import-relatively-large-csv-file-with-julia-and-vsc/112350 "2024-09-22T12:53:54Z")

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Hello everyone, I am completly new to Julia, so please my apologies if my question is trivial. I have quickly looked for the reply and I have not found it. I need to import a large matrix (40 000 x 40 000, app 6GB) int…

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## [How to show all xlabels in violin plot](https://discourse.julialang.org/t/how-to-show-all-xlabels-in-violin-plot/119627)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 5\
**Last updated:** [September 21, 2024, 8:11pm UTC](https://discourse.julialang.org/t/how-to-show-all-xlabels-in-violin-plot/119627 "2024-09-21T20:11:29Z")

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Hi, In the code below, only evenly indexed labels display. How do I show all xlabels? Thanks! using StatsPlots x = randn(1000, 16) labels = map(x -\> randstring(3), 1:16) violin(permutedims(labels), x, rotation = 90, …

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## [Help with gradient-based optimizers](https://discourse.julialang.org/t/help-with-gradient-based-optimizers/119376)

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**Author:** [@jwalker](https://discourse.julialang.org/u/jwalker)\
**Replies:** 14\
**Last updated:** [September 21, 2024, 8:03pm UTC](https://discourse.julialang.org/t/help-with-gradient-based-optimizers/119376 "2024-09-21T20:03:11Z")

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I’m using Optimization.jl and Optim.jl to solve an optimization problem for which I have gradient information (via AD). What I’ve found is that the methods that use the gradient information perform worse than the derivat…

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## [Set defaults for a part of Symbolics.Arr](https://discourse.julialang.org/t/set-defaults-for-a-part-of-symbolics-arr/119678)

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**Author:** [@Bart\_van\_de\_Lint](https://discourse.julialang.org/u/Bart_van_de_Lint)\
**Replies:** 1\
**Last updated:** [September 21, 2024, 3:51pm UTC](https://discourse.julialang.org/t/set-defaults-for-a-part-of-symbolics-arr/119678 "2024-09-21T15:51:30Z")

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Is it possible to set defaults for only a part of a Symbolics.Arr when defining a model? So can I for example only set defaults for pos\[:, 4:8\], while not setting defaults for pos\[:, 1:3\] and pos\[:, 9:10\]? @variables …

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## [ModelingToolkit 9.39 is broken, 9.40.1 works well](https://discourse.julialang.org/t/modelingtoolkit-9-39-is-broken-9-40-1-works-well/119670)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 7\
**Last updated:** [September 21, 2024, 2:40pm UTC](https://discourse.julialang.org/t/modelingtoolkit-9-39-is-broken-9-40-1-works-well/119670 "2024-09-21T14:40:03Z")

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Steps to reproduce: git clone https://github.com/ufechner7/Tethers.jl/ cd Tethers.jl git checkout broken julia --project and then in Julia using Pkg Pkg.update() include("src/Tether\_01.jl") This gives the following …

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## [Julia Images adaptive histogram equalization vs MATLAB's implementation](https://discourse.julialang.org/t/julia-images-adaptive-histogram-equalization-vs-matlabs-implementation/119469)

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**Author:** [@cpaniaguam](https://discourse.julialang.org/u/cpaniaguam)\
**Replies:** 1\
**Last updated:** [September 21, 2024, 1:04pm UTC](https://discourse.julialang.org/t/julia-images-adaptive-histogram-equalization-vs-matlabs-implementation/119469 "2024-09-21T13:04:55Z")

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I’m hoping to get an expert’s opinion on this matter. In MATLAB: \>\> img = imread('cameraman.tif'); \>\> class(img) ans = 'uint8' \>\> sum(img(:)) ans = 7780728 \>\> img\_eq = adapthisteq(img, Range="original", …

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## [MTK - struggling with initialization](https://discourse.julialang.org/t/mtk-struggling-with-initialization/119643)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 5\
**Last updated:** [September 21, 2024, 10:38am UTC](https://discourse.julialang.org/t/mtk-struggling-with-initialization/119643 "2024-09-21T10:38:11Z")

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I’m converting a model from Modelica to ModelingToolkit \[MTK\]. The Modelica-version works fine using OpenModelica, but the ModelingToolkit has problems wrt. initialization. Here is the Julia+MTK code that is equivalent …

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