# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=188

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

**Page:** 189

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## [Rust in HPC study](https://discourse.julialang.org/t/rust-in-hpc-study/99834)

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**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 0\
**Last updated:** [June 4, 2023, 7:24am UTC](https://discourse.julialang.org/t/rust-in-hpc-study/99834 "2023-06-04T07:24:30Z")

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OK, specific to Rust. I will happily move to another category. however this may be interesting to the audience here. Quote: The three languages used are Rust, C, and Fortran and the programme is run for serial and paral…

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## [Accelerating linear methods](https://discourse.julialang.org/t/accelerating-linear-methods/99685)

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**Author:** [@Leticia-maria](https://discourse.julialang.org/u/Leticia-maria)\
**Replies:** 11\
**Last updated:** [June 3, 2023, 11:15pm UTC](https://discourse.julialang.org/t/accelerating-linear-methods/99685 "2023-06-03T23:15:57Z")

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Dear Julia friends, I am benchmarking Julia for linear regression models and trying to optimize that for high-dimensional spaces. Any suggestions on the code below to reduce allocations and speed up the code? Thank you s…

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## [Second Fick Law -- NeuralPDE](https://discourse.julialang.org/t/second-fick-law-neuralpde/99497)

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**Author:** [@aquarelleX332](https://discourse.julialang.org/u/aquarelleX332)\
**Replies:** 9\
**Last updated:** [June 3, 2023, 8:37pm UTC](https://discourse.julialang.org/t/second-fick-law-neuralpde/99497 "2023-06-03T20:37:34Z")

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Hello everyone, I’m trying to solve Fick’s second law (1D), which is analogous to the thermal diffusion equation (or heat equation). Fick’s equation explains how a solute diffuses in a solvent. I was inspired by this c…

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## [First time using Jump](https://discourse.julialang.org/t/first-time-using-jump/99819)

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**Author:** [@A.Marx](https://discourse.julialang.org/u/A.Marx)\
**Replies:** 3\
**Last updated:** [June 3, 2023, 8:25pm UTC](https://discourse.julialang.org/t/first-time-using-jump/99819 "2023-06-03T20:25:18Z")

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Hello all, I am new to JuMP and Julia. I am getting this error: LoadError: UndefVarError: @optimize! not defined in expression starting at c:\\Users\\alex-\\Documents\\OR Lab\\Introduction to Julia JuMP.jl:49 After @opti…

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## [Legend for functions in a separate (stacked) plot](https://discourse.julialang.org/t/legend-for-functions-in-a-separate-stacked-plot/99796)

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**Author:** [@nsajko](https://discourse.julialang.org/u/nsajko)\
**Replies:** 3\
**Last updated:** [June 3, 2023, 7:20pm UTC](https://discourse.julialang.org/t/legend-for-functions-in-a-separate-stacked-plot/99796 "2023-06-03T19:20:41Z")

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TLDR: In Gadfly, what’s the best way to put a legend for a plot into a separate (stacked) plot instead? My problem Current solution I have a module like this for a specific plotting use case: module Plotting using Gad…

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## [Use DataLoader in Flux DimensionMismatch](https://discourse.julialang.org/t/use-dataloader-in-flux-dimensionmismatch/99810)

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**Author:** [@Ordens\_Ritter](https://discourse.julialang.org/u/Ordens_Ritter)\
**Replies:** 0\
**Last updated:** [June 3, 2023, 1:46pm UTC](https://discourse.julialang.org/t/use-dataloader-in-flux-dimensionmismatch/99810 "2023-06-03T13:46:38Z")

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I am trying to train this tiny net in Flux: NN = Chain( Dense(2 =\> 16, tanh), Dense(16 =\> 16, tanh), Dense(16 =\> 1) ) |\> f64 I the data comes from a single DataFrame, that I mask, convert the temp to Kelvin and…

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## [Solving stiff DAE with Float32 inputs for parallel simulations](https://discourse.julialang.org/t/solving-stiff-dae-with-float32-inputs-for-parallel-simulations/99742)

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**Author:** [@Ricardo\_Rodrigues](https://discourse.julialang.org/u/Ricardo_Rodrigues)\
**Replies:** 5\
**Last updated:** [June 3, 2023, 4:51am UTC](https://discourse.julialang.org/t/solving-stiff-dae-with-float32-inputs-for-parallel-simulations/99742 "2023-06-03T04:51:59Z")

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Hello all! I’m using DifferentialEquations.jl to solve a stiff DAE. I’ve tried both mass matrix and in-place methods with Rodas4 and IDA respectively at tolerances of 1e-8, and the result is the same (albeit IDA tends t…

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## [How to plot the output of the PI controller?](https://discourse.julialang.org/t/how-to-plot-the-output-of-the-pi-controller/99789)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 2\
**Last updated:** [June 2, 2023, 9:53pm UTC](https://discourse.julialang.org/t/how-to-plot-the-output-of-the-pi-controller/99789 "2023-06-02T21:53:40Z")

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I have the following code: using ControlSystemsBase, Plots P\_sc = 4.42616018443722e6 I\_sc = 11838.3957271545\*4 P = tf(-1.898e-8, \[1, 0.01934\]) C = -pid(P\_sc, I\_sc) FS = feedback(P\*C) I can plot the step response of t…

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## [Kolmogorov-Smirnov test for PDF](https://discourse.julialang.org/t/kolmogorov-smirnov-test-for-pdf/99771)

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**Author:** [@Sergey\_Novak](https://discourse.julialang.org/u/Sergey_Novak)\
**Replies:** 5\
**Last updated:** [June 2, 2023, 7:46pm UTC](https://discourse.julialang.org/t/kolmogorov-smirnov-test-for-pdf/99771 "2023-06-02T19:46:07Z")

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Hello! I have probability density function(PDF) for my data. I need use Kolmogorov-Smirnov test to check which distribution corresponds PDF. I have not dealt with statistics before, is it possible to throw off some ex…

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## [How to run MPI jobs on a cluster](https://discourse.julialang.org/t/how-to-run-mpi-jobs-on-a-cluster/97191)

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**Author:** [@Neo](https://discourse.julialang.org/u/Neo)\
**Replies:** 1\
**Last updated:** [June 2, 2023, 6:56pm UTC](https://discourse.julialang.org/t/how-to-run-mpi-jobs-on-a-cluster/97191 "2023-06-02T18:56:00Z")

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I want to run Julia MPI jobs on a cluster but not sure if I did it in the correct way. There is a large cluster with hundreds of nodes where each node has 128 cores. The resource management system on the cluster is SLUR…

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## [How to determine the -3dB frequency of a system](https://discourse.julialang.org/t/how-to-determine-the-3db-frequency-of-a-system/99755)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 4\
**Last updated:** [June 2, 2023, 4:06pm UTC](https://discourse.julialang.org/t/how-to-determine-the-3db-frequency-of-a-system/99755 "2023-06-02T16:06:44Z")

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I have the following system, controlled with a PI controller: using ControlSystemsBase, Plots P\_sc = 4.42616018443722e6 I\_sc = 11838.3957271545\*4 P = tf(-1.898e-8, \[1, 0.01934\]) C = -pid(P\_sc, I\_sc) PC = feedback(P\*C…

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## [How to have multiple labelcolors in legend?](https://discourse.julialang.org/t/how-to-have-multiple-labelcolors-in-legend/99745)

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**Author:** [@Gianluca\_Fuwa](https://discourse.julialang.org/u/Gianluca_Fuwa)\
**Replies:** 1\
**Last updated:** [June 2, 2023, 5:04am UTC](https://discourse.julialang.org/t/how-to-have-multiple-labelcolors-in-legend/99745 "2023-06-02T05:04:49Z")

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Hi, is there a way to have to have more than one :labelcolor in a Legend() or axislegend()? Specifically in my case, I am trying to make each label be the same color as the line it represents, like plt.legend(labelcol…

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## [About using powermodels to solve problems with SDP-OPF](https://discourse.julialang.org/t/about-using-powermodels-to-solve-problems-with-sdp-opf/99750)

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**Author:** [@lzq-zbc](https://discourse.julialang.org/u/lzq-zbc)\
**Replies:** 1\
**Last updated:** [June 2, 2023, 3:36am UTC](https://discourse.julialang.org/t/about-using-powermodels-to-solve-problems-with-sdp-opf/99750 "2023-06-02T03:36:35Z")

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I want to use the ECOS solver to solve some errors in the SDP model in OPF. using JuMP, PowerModels, Ipopt,ECOS file\_name = "E:/Vscode——data/data/case5.m" model = Model(ECOS.Optimizer) power\_model = PowerModels.instan…

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## [Neumann series expander for solving linear problem?](https://discourse.julialang.org/t/neumann-series-expander-for-solving-linear-problem/99736)

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**Author:** [@ehgus](https://discourse.julialang.org/u/ehgus)\
**Replies:** 3\
**Last updated:** [June 2, 2023, 1:48am UTC](https://discourse.julialang.org/t/neumann-series-expander-for-solving-linear-problem/99736 "2023-06-02T01:48:49Z")

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Is there a package providing Neumann series expansion for solving linear problem? I usually solve Ax = b by calculating x = b + Sb + SSb + SSSb ... where S = 1- A, and I’d like to convert my matlab code into Julia. So …

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## [Julia exits when running several models (JuMP) in a row](https://discourse.julialang.org/t/julia-exits-when-running-several-models-jump-in-a-row/99686)

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**Author:** [@Yuri\_Masakazu\_Mizusa](https://discourse.julialang.org/u/Yuri_Masakazu_Mizusa)\
**Replies:** 6\
**Last updated:** [June 1, 2023, 11:08pm UTC](https://discourse.julialang.org/t/julia-exits-when-running-several-models-jump-in-a-row/99686 "2023-06-01T23:08:01Z")

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Hi, I’m running several instances on the same model in order to compare performance, like described below. My problem is that I have 1000 instances and halfway Julia exit, probably due to memory, but I don’t really und…

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## [Makie Alpha property in colormap is not observable. What's best way to mech this?](https://discourse.julialang.org/t/makie-alpha-property-in-colormap-is-not-observable-whats-best-way-to-mech-this/99731)

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**Author:** [@Allan\_Baker](https://discourse.julialang.org/u/Allan_Baker)\
**Replies:** 2\
**Last updated:** [June 1, 2023, 6:03pm UTC](https://discourse.julialang.org/t/makie-alpha-property-in-colormap-is-not-observable-whats-best-way-to-mech-this/99731 "2023-06-01T18:03:35Z")

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I have a function that makes a plot using lines/lines!. I can pass observables into the function and get the line x,y,z, and colormap value to update dynamically. The alpha value does not update as an observable. What…

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## [Axis limits in 3D Makie plot](https://discourse.julialang.org/t/axis-limits-in-3d-makie-plot/99730)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 0\
**Last updated:** [June 1, 2023, 2:13pm UTC](https://discourse.julialang.org/t/axis-limits-in-3d-makie-plot/99730 "2023-06-01T14:13:50Z")

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How can I set the axis limits in this Makie code? using Distributions using Makie using WGLMakie N = 50 lat = rand(-20.:20., N) lon = rand(-180.:180., N) temp\_dist = Normal(85, 5) temp = rand(temp\_dist, N) dat…

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## [Speed up compilation with Zygote and PINN](https://discourse.julialang.org/t/speed-up-compilation-with-zygote-and-pinn/99652)

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**Author:** [@Matthieu\_BARREAU](https://discourse.julialang.org/u/Matthieu_BARREAU)\
**Replies:** 4\
**Last updated:** [June 1, 2023, 1:01pm UTC](https://discourse.julialang.org/t/speed-up-compilation-with-zygote-and-pinn/99652 "2023-06-01T13:01:23Z")

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Hi! I am relatively new to Julia and I am trying to move all my research projects to this new ecosystem instead of Python. However, I have trouble when my project deals with Physics informed neural network. Since I am …

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## [Heatmap using categorical colours](https://discourse.julialang.org/t/heatmap-using-categorical-colours/99717)

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**Author:** [@pascal](https://discourse.julialang.org/u/pascal)\
**Replies:** 3\
**Last updated:** [June 1, 2023, 10:18am UTC](https://discourse.julialang.org/t/heatmap-using-categorical-colours/99717 "2023-06-01T10:18:37Z")

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I plot a heatmap of as using CairoMakie x=\[1; 2; 1; 2; 501; 500; 501; 500\] f = Figure() ax = Axis(f\[1,1\]) hm = heatmap!(ax, ones(8), 1:8, x, colormap=cgrad(:viridis, 4, categorical=true)) Colorbar(f\[:, 2\], hm) f Can I …

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## [LinearAlgebra.\* hangs when in a @threads loop on Apple M2 running 1.9.0 x86\_64](https://discourse.julialang.org/t/linearalgebra-hangs-when-in-a-threads-loop-on-apple-m2-running-1-9-0-x86-64/99630)

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**Author:** [@pitsianis](https://discourse.julialang.org/u/pitsianis)\
**Replies:** 6\
**Last updated:** [June 1, 2023, 7:21am UTC](https://discourse.julialang.org/t/linearalgebra-hangs-when-in-a-threads-loop-on-apple-m2-running-1-9-0-x86-64/99630 "2023-06-01T07:21:18Z")

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MacBook-Pro-M2 ~\> file /Applications/Julia-1.9.app/Contents/Resources/julia/bin/julia /Applications/Julia-1.9.app/Contents/Resources/julia/bin/julia: Mach-O 64-bit executable x86\_64 MacBook-Pro-M2 ~\> julia -t auto …

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## [High-dimensional optimization problem with inequality constraint](https://discourse.julialang.org/t/high-dimensional-optimization-problem-with-inequality-constraint/63957)

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**Author:** [@mengxiaoliu](https://discourse.julialang.org/u/mengxiaoliu)\
**Replies:** 10\
**Last updated:** [June 1, 2023, 7:03am UTC](https://discourse.julialang.org/t/high-dimensional-optimization-problem-with-inequality-constraint/63957 "2023-06-01T07:03:33Z")

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Hello, I am solving a high-dimensional optimization problem with an inequality constraint using blackboxoptim. The objective function is differentiable, but I cannot write down the Hessians by hand. The dimensionality i…

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## [Flux runs out of memory](https://discourse.julialang.org/t/flux-runs-out-of-memory/73046)

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**Author:** [@sheevy](https://discourse.julialang.org/u/sheevy)\
**Replies:** 25\
**Last updated:** [June 1, 2023, 6:35am UTC](https://discourse.julialang.org/t/flux-runs-out-of-memory/73046 "2023-06-01T06:35:35Z")

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I’m running training conv net on 2000x2000 pixel image with Flux/Zygote on RTX 3070 (mobile) with 8GB of RAM and I’m getting out of memory exception when gradients are calculated: ERROR: LoadError: Out of GPU memory try…

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## [Higher order derivatives with ParallelStencil](https://discourse.julialang.org/t/higher-order-derivatives-with-parallelstencil/99647)

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**Author:** [@Teerthal](https://discourse.julialang.org/u/Teerthal)\
**Replies:** 2\
**Last updated:** [May 31, 2023, 6:24pm UTC](https://discourse.julialang.org/t/higher-order-derivatives-with-parallelstencil/99647 "2023-05-31T18:24:01Z")

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I am currently implementing a numerical simulation code on multiple GPUs using ParallelStencil+ImplicitGlobalGrid. I wanted to use higher order numerical differentiation schemes which I could easily do by extending the …

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## [Two subfigures with PlotlyJS.jl](https://discourse.julialang.org/t/two-subfigures-with-plotlyjs-jl/99666)

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**Author:** [@ga72kud](https://discourse.julialang.org/u/ga72kud)\
**Replies:** 1\
**Last updated:** [May 31, 2023, 4:45pm UTC](https://discourse.julialang.org/t/two-subfigures-with-plotlyjs-jl/99666 "2023-05-31T16:45:35Z")

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I am using the great PlotlyJS package for map visualization. I want to have two subfigures with USA and Europe map. I can the following code, but the subfigures do not scale adequate using PlotlyJS, DataFrames using XLS…

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## [Odd error for contour plots with PGFPlotsX](https://discourse.julialang.org/t/odd-error-for-contour-plots-with-pgfplotsx/99670)

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**Author:** [@theo](https://discourse.julialang.org/u/theo)\
**Replies:** 0\
**Last updated:** [May 31, 2023, 12:17pm UTC](https://discourse.julialang.org/t/odd-error-for-contour-plots-with-pgfplotsx/99670 "2023-05-31T12:17:40Z")

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So some of my contour plots with PGFPlotsX are breaking, others are not. I tried to find a simple way to reproduce the error and realised it breaks if I try to plot anything that’s flat… Can anyone explain this? julia\> …

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## [Training NN with Loss from Differential Equation](https://discourse.julialang.org/t/training-nn-with-loss-from-differential-equation/99669)

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**Author:** [@Duarte\_Magano](https://discourse.julialang.org/u/Duarte_Magano)\
**Replies:** 0\
**Last updated:** [May 31, 2023, 12:09pm UTC](https://discourse.julialang.org/t/training-nn-with-loss-from-differential-equation/99669 "2023-05-31T12:09:56Z")

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Hello! Say I have a differential equation of the form du/dt = NN(u), where NN(u) is the output of a neural network that takes as input the current value of u. The boundary condition is u(0) = 0. I want to train the ne…

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## [Freezing neural network parameters in Universal Differential Equation framework](https://discourse.julialang.org/t/freezing-neural-network-parameters-in-universal-differential-equation-framework/99661)

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**Author:** [@Stefano\_Giampiccolo](https://discourse.julialang.org/u/Stefano_Giampiccolo)\
**Replies:** 2\
**Last updated:** [May 31, 2023, 9:44am UTC](https://discourse.julialang.org/t/freezing-neural-network-parameters-in-universal-differential-equation-framework/99661 "2023-05-31T09:44:25Z")

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Hi, I’m working on hybrid systems with the SciML framework, approximating one of the derivatives of an ODE system with a neural network. When I attempt, using Lux.freeze, to freeze some of the network parameters that I …

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## [UndefVarError: \_pass\_variable\_names\_to\_solver not defined - Xpress solver in Julia](https://discourse.julialang.org/t/undefvarerror-pass-variable-names-to-solver-not-defined-xpress-solver-in-julia/99292)

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**Author:** [@Ignacio](https://discourse.julialang.org/u/Ignacio)\
**Replies:** 4\
**Last updated:** [May 31, 2023, 7:41am UTC](https://discourse.julialang.org/t/undefvarerror-pass-variable-names-to-solver-not-defined-xpress-solver-in-julia/99292 "2023-05-31T07:41:12Z")

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Good evening, I am building an optimization model, in which I want to pass the names of the variables and constranits to the solver, so an IIS can be built afterwards if the problem turns out to be infeasible. I am usin…

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## [Illegal memory indexing for broadcast of a recursive function](https://discourse.julialang.org/t/illegal-memory-indexing-for-broadcast-of-a-recursive-function/99534)

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**Author:** [@albertomercurio](https://discourse.julialang.org/u/albertomercurio)\
**Replies:** 6\
**Last updated:** [May 31, 2023, 7:20am UTC](https://discourse.julialang.org/t/illegal-memory-indexing-for-broadcast-of-a-recursive-function/99534 "2023-05-31T07:20:16Z")

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Hello, I’m trying to implement the generalized Laguerre function acting element-wise to the elements of a CuArray. The basic code uses a recursive function to evaluate the laguerre polynomial using CUDA using LinearAl…

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## [Second derivative in Zygote returns nothing](https://discourse.julialang.org/t/second-derivative-in-zygote-returns-nothing/99624)

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**Author:** [@jarroyoe](https://discourse.julialang.org/u/jarroyoe)\
**Replies:** 1\
**Last updated:** [May 31, 2023, 3:59am UTC](https://discourse.julialang.org/t/second-derivative-in-zygote-returns-nothing/99624 "2023-05-31T03:59:13Z")

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I need to optimize a function that depends on the gradient of another function. When I run the following code: using Zygote data = rand(1,10) f(p,x) = \[x\*p\[1\];x\*p\[2\].+p\[3\]\] truef(x) = \[x.+1;2\*x\] function loss(p) …

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