# Latest

**URL:** https://discourse.julialang.org/latest.md?page=236

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

**Page:** 237

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## [Proposal-A-Thon](https://discourse.julialang.org/t/proposal-a-thon/124798)

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**Author:** [@sgering](https://discourse.julialang.org/u/sgering)\
**Replies:** 0\
**Last updated:** [January 15, 2025, 4:27pm UTC](https://discourse.julialang.org/t/proposal-a-thon/124798 "2025-01-15T16:27:18Z")

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The JuliaCon 2025 Diversity, Equity, and Inclusion (DEI) Committee is excited to announce a Proprosal-A-Thon for writing your JuliaCon 2025 proposal! The call for proposals is out right now, and we are looking for both t…

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## [Calling All JuliaGPU Enthusiasts! Abstract Submissions Now Open for JuliaCon 2025 🚀](https://discourse.julialang.org/t/calling-all-juliagpu-enthusiasts-abstract-submissions-now-open-for-juliacon-2025/124858)

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**Author:** [@luraess](https://discourse.julialang.org/u/luraess)\
**Replies:** 0\
**Last updated:** [January 17, 2025, 7:56am UTC](https://discourse.julialang.org/t/calling-all-juliagpu-enthusiasts-abstract-submissions-now-open-for-juliacon-2025/124858 "2025-01-17T07:56:11Z")

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The JuliaGPU community has been a cornerstone of JuliaCon for years, delivering countless inspiring talks on GPU computing. In 2025, we’re taking it a step further with a dedicated GPU minisymposium! This event will tac…

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## [JuliaCon 2025 Updates - Jan 2025](https://discourse.julialang.org/t/juliacon-2025-updates-jan-2025/124651)

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**Author:** [@ranjan](https://discourse.julialang.org/u/ranjan)\
**Replies:** 0\
**Last updated:** [January 10, 2025, 5:44pm UTC](https://discourse.julialang.org/t/juliacon-2025-updates-jan-2025/124651 "2025-01-10T17:44:47Z")

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Hello all, Happy new year to everyone from the JuliaCon organizing committee! I just wanted to provide a general update on JuliaCon: We are starting to receive your proposals, and we love them! Please keep them coming,…

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## [Using ODE solvers for accelerator physics project](https://discourse.julialang.org/t/using-ode-solvers-for-accelerator-physics-project/124853)

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**Author:** [@Oleksii](https://discourse.julialang.org/u/Oleksii)\
**Replies:** 1\
**Last updated:** [January 17, 2025, 9:27am UTC](https://discourse.julialang.org/t/using-ode-solvers-for-accelerator-physics-project/124853 "2025-01-17T09:27:58Z")

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Hi! I would like to incorporate DiffentialEquations for our Accelerator Physicists particle tracking code. The set up is the following: ensembles of particles are moving through the sequence of magnets each having a len…

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## [How to get started modeling systems in SciML](https://discourse.julialang.org/t/how-to-get-started-modeling-systems-in-sciml/124780)

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**Author:** [@slwu89](https://discourse.julialang.org/u/slwu89)\
**Replies:** 2\
**Last updated:** [January 17, 2025, 9:26am UTC](https://discourse.julialang.org/t/how-to-get-started-modeling-systems-in-sciml/124780 "2025-01-17T09:26:59Z")

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Hi everyone. I would like to port a “systems modeling” approach from R into SciML and have some questions about how to start. Let me describe some background. Several years ago I and coauthors worked out a method to simu…

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## [Improving DAE performance](https://discourse.julialang.org/t/improving-dae-performance/124775)

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**Author:** [@clm](https://discourse.julialang.org/u/clm)\
**Replies:** 5\
**Last updated:** [January 17, 2025, 9:26am UTC](https://discourse.julialang.org/t/improving-dae-performance/124775 "2025-01-17T09:26:54Z")

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I’m looking to solve two implicitly-defined nonlinear ODEs. The system diverges toward the final integration z=H, but in a way that I expect, T\\sim1/(H-z) and u\\sim\\log(H-z), plus constants. What I’m hoping to do is int…

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## [Broadcast matrix valued function, output into existing array](https://discourse.julialang.org/t/broadcast-matrix-valued-function-output-into-existing-array/124831)

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**Author:** [@eveningsilverfox](https://discourse.julialang.org/u/eveningsilverfox)\
**Replies:** 7\
**Last updated:** [January 17, 2025, 6:42am UTC](https://discourse.julialang.org/t/broadcast-matrix-valued-function-output-into-existing-array/124831 "2025-01-17T06:42:50Z")

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How do I broadcast the function matop below such that the output car1 resembles car, i.e., car1 is an array which can be accessed as car1\[:,1,2\]? Presently, car1 looks like a vector, with size (N,), instead of (N,2,2). …

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## [Poor parallel speedup](https://discourse.julialang.org/t/poor-parallel-speedup/124782)

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**Author:** [@billmclean](https://discourse.julialang.org/u/billmclean)\
**Replies:** 2\
**Last updated:** [January 17, 2025, 3:14am UTC](https://discourse.julialang.org/t/poor-parallel-speedup/124782 "2025-01-17T03:14:49Z")

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I want to understand why some code exhibits fairly poor parallel speedup. In simplified form, I am just computing a discrete Laplacian over a 3D grid: function discrete\_laplacian!(AU::Array{T,3}, U::OffsetArray{T,3}) w…

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## [Evaluate symbol passed to macro](https://discourse.julialang.org/t/evaluate-symbol-passed-to-macro/124810)

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**Author:** [@Mikhail\_Kagalenko](https://discourse.julialang.org/u/Mikhail_Kagalenko)\
**Replies:** 7\
**Last updated:** [January 17, 2025, 12:32am UTC](https://discourse.julialang.org/t/evaluate-symbol-passed-to-macro/124810 "2025-01-17T00:32:37Z")

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I have a macro that builds some Expr from a string passed to it, a simplified MWE is module MyExpr export @my\_expr macro my\_expr(s::String) Symbol.(eachsplit(s)) end end So I can call it like this julia\> @my\_ex…

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## [Create executable file to be used in another julia project](https://discourse.julialang.org/t/create-executable-file-to-be-used-in-another-julia-project/124777)

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**Author:** [@Sandy45](https://discourse.julialang.org/u/Sandy45)\
**Replies:** 8\
**Last updated:** [January 16, 2025, 9:37pm UTC](https://discourse.julialang.org/t/create-executable-file-to-be-used-in-another-julia-project/124777 "2025-01-16T21:37:47Z")

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I am trying to create executable file(probably .so file) that can be used in my another julia project to access methods in it. I have tried to do it so using package compiler but getting below errors while using methods …

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## [Handling of saturated integrator with anti-windeup](https://discourse.julialang.org/t/handling-of-saturated-integrator-with-anti-windeup/124819)

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**Author:** [@hexaeder](https://discourse.julialang.org/u/hexaeder)\
**Replies:** 7\
**Last updated:** [January 16, 2025, 7:40pm UTC](https://discourse.julialang.org/t/handling-of-saturated-integrator-with-anti-windeup/124819 "2025-01-16T19:40:32Z")

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I want to model a saturated integrator T\\dot{u} ~ = r\_\\mathrm{ref}-u in which u follows r\_\\mathrm{ref} but is also bounded to stay within u\\in(u\_\\mathrm{min}, u\_\\mathrm{max}). To prevent windeup effects, the integrato…

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## [Why is a const binding not always a type alias?](https://discourse.julialang.org/t/why-is-a-const-binding-not-always-a-type-alias/61884)

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**Author:** [@jlapeyre](https://discourse.julialang.org/u/jlapeyre)\
**Replies:** 10\
**Last updated:** [January 16, 2025, 7:38pm UTC](https://discourse.julialang.org/t/why-is-a-const-binding-not-always-a-type-alias/61884 "2025-01-16T19:38:27Z")

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With this struct A{T} end const Dog = A{String} const Cat = A{Int} I have julia\> Dog Dog (alias for A{String}) julia\> Cat Cat (alias for A{Int64}) But with this struct A{T} end const Dog = A{String} const Cat = A…

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## [Feature request: --project=@script\_dir](https://discourse.julialang.org/t/feature-request-project-script-dir/124828)

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**Author:** [@greatpet](https://discourse.julialang.org/u/greatpet)\
**Replies:** 3\
**Last updated:** [January 16, 2025, 4:14pm UTC](https://discourse.julialang.org/t/feature-request-project-script-dir/124828 "2025-01-16T16:14:56Z")

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I’d like to run a command like julia --project=@script\_dir long/path/to/my/package/src/script.jl rather than what I currently have to use, where the path is repeated verbatim julia --project=long/path/to/my/package lo…

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## [Julia stopped working](https://discourse.julialang.org/t/julia-stopped-working/124834)

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**Author:** [@Torkel](https://discourse.julialang.org/u/Torkel)\
**Replies:** 7\
**Last updated:** [January 16, 2025, 3:47pm UTC](https://discourse.julialang.org/t/julia-stopped-working/124834 "2025-01-16T15:47:34Z")

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Julia stopped working. I came back ot my computer today (it was fine yesterday), and now it won’t start in vscode (latest version on ubuntu 24.04). I tried in terminal but get this: loman@famous-fred:~$ julia Error: The…

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## [Segfault calling into Julia from C/MPI](https://discourse.julialang.org/t/segfault-calling-into-julia-from-c-mpi/124800)

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**Author:** [@liamh](https://discourse.julialang.org/u/liamh)\
**Replies:** 1\
**Last updated:** [January 16, 2025, 3:12pm UTC](https://discourse.julialang.org/t/segfault-calling-into-julia-from-c-mpi/124800 "2025-01-16T15:12:14Z")

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I have written a Julia package and compiled a shared object library to call one @ccallable function. When I test it with a serial C program, it works fine. When I call it from a more complex program using MPI (even when …

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## [Wrong heatmap orientation with Plots.jl](https://discourse.julialang.org/t/wrong-heatmap-orientation-with-plots-jl/124822)

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**Author:** [@peremato](https://discourse.julialang.org/u/peremato)\
**Replies:** 16\
**Last updated:** [January 16, 2025, 2:53pm UTC](https://discourse.julialang.org/t/wrong-heatmap-orientation-with-plots-jl/124822 "2025-01-16T14:53:12Z")

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I do not understand what I am doing wrong plotting a 2D function. The resulted heatmap is rotated 90 deg. using Plots rosenbrock(x, y; a=1, b=100) = (a - x)^2 + b\*(y - x^2)^2 # Define the range for x and y x = -2:0.01…

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## [Is there a package for Sliding Discrete Fourier Transforms?](https://discourse.julialang.org/t/is-there-a-package-for-sliding-discrete-fourier-transforms/122320)

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**Author:** [@heliosdrm](https://discourse.julialang.org/u/heliosdrm)\
**Replies:** 4\
**Last updated:** [January 16, 2025, 2:13pm UTC](https://discourse.julialang.org/t/is-there-a-package-for-sliding-discrete-fourier-transforms/122320 "2025-01-16T14:13:53Z")

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I haven’t found any specific package for Sliding Discrete Fourier Transforms. If there is no one yet, I would be inclined to try draft one (with the simplest methods to start with), but in that case I would appreciate so…

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## [Rational Polynomial Substitution](https://discourse.julialang.org/t/rational-polynomial-substitution/124820)

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**Author:** [@gustave\_Robichon](https://discourse.julialang.org/u/gustave_Robichon)\
**Replies:** 1\
**Last updated:** [January 16, 2025, 2:12pm UTC](https://discourse.julialang.org/t/rational-polynomial-substitution/124820 "2025-01-16T14:12:54Z")

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Hello there :slight\_smile: I am using some Rational Polynomial object. I want to substitute some variables inside it. How can I do ? Here is the code : using DynamicPolynomials @polyvar eta\_var eta = (0.0 + (1.0+0.0im)…

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## [Automatic Differentiation (AD) in Julia vs. Python (or PyTorch)](https://discourse.julialang.org/t/automatic-differentiation-ad-in-julia-vs-python-or-pytorch/124553)

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**Author:** [@wsshin](https://discourse.julialang.org/u/wsshin)\
**Replies:** 14\
**Last updated:** [January 16, 2025, 11:52am UTC](https://discourse.julialang.org/t/automatic-differentiation-ad-in-julia-vs-python-or-pytorch/124553 "2025-01-16T11:52:55Z")

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(I find that there were related discussions already: Automatic Differentiation (AD) in Python compared to Julia and AD Basics Automatic differentiation - Julia implementation advantages. But they were at least 4 years…

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## [\[ANN\] Splinegrids.jl - Evaluating and optimizing locally refined or weighted spline geometries](https://discourse.julialang.org/t/ann-splinegrids-jl-evaluating-and-optimizing-locally-refined-or-weighted-spline-geometries/124824)

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**Author:** [@BdeKoning](https://discourse.julialang.org/u/BdeKoning)\
**Replies:** 0\
**Last updated:** [January 16, 2025, 10:31am UTC](https://discourse.julialang.org/t/ann-splinegrids-jl-evaluating-and-optimizing-locally-refined-or-weighted-spline-geometries/124824 "2025-01-16T10:31:38Z")

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I’m happy to announce that my package SplineGrids.jl has been registered. See my pre-announcement of a more elaborate introduction of the package. I’m especially proud of the implementation of Local refinement (THB-spli…

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## [Makie.jl: how to display labels on a waterfall chart](https://discourse.julialang.org/t/makie-jl-how-to-display-labels-on-a-waterfall-chart/124742)

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**Author:** [@ajk](https://discourse.julialang.org/u/ajk)\
**Replies:** 3\
**Last updated:** [January 16, 2025, 9:00am UTC](https://discourse.julialang.org/t/makie-jl-how-to-display-labels-on-a-waterfall-chart/124742 "2025-01-16T09:00:27Z")

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Hi, I can’t figure out how to label the bars in a Makie waterfall chart anymore. It used to be possible to pass all barplot options to waterfall(...), e.g. the following code used to run. Since updating I now have to com…

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## [Multivariate Taylor Series Problem](https://discourse.julialang.org/t/multivariate-taylor-series-problem/124807)

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**Author:** [@usaer](https://discourse.julialang.org/u/usaer)\
**Replies:** 2\
**Last updated:** [January 16, 2025, 8:50am UTC](https://discourse.julialang.org/t/multivariate-taylor-series-problem/124807 "2025-01-16T08:50:02Z")

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Hi, I was using the package TaylorSeries to find out taylor approximation of a simple multivariate function f(x,y)=x^2+y^2. For the simple approximation around point (0,0) this works fine. However, if i want to expand a…

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## [Parallel Assembly of Matrices in FEM](https://discourse.julialang.org/t/parallel-assembly-of-matrices-in-fem/124561)

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**Author:** [@priyanshuFSI](https://discourse.julialang.org/u/priyanshuFSI)\
**Replies:** 8\
**Last updated:** [January 16, 2025, 4:46am UTC](https://discourse.julialang.org/t/parallel-assembly-of-matrices-in-fem/124561 "2025-01-16T04:46:58Z")

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Hi. I am writing a CFD solver using Finite Element Methods. I encounter issues in assembling the sparse matrices( specially in regards with the performance). I construct a sparse matrix in CSC form. This function works f…

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## [Seeking clarification on Ptr vs Ref in ccall](https://discourse.julialang.org/t/seeking-clarification-on-ptr-vs-ref-in-ccall/96883)

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**Author:** [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Replies:** 11\
**Last updated:** [January 16, 2025, 12:42am UTC](https://discourse.julialang.org/t/seeking-clarification-on-ptr-vs-ref-in-ccall/96883 "2025-01-16T00:42:39Z")

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Suppose I have a C code int sum(int \*a, int n){ int s = 0; for(int i=0; i\<n; i++){ s += a\[i\]; } return s; } and I can call this from Julia as julia\> ccall((:sum, "./libsum.so"), Cint, (Ref{Cint},Cint), Cint\[1,2,…

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## [Why must the second argument of \`hash\` come from another hash function?](https://discourse.julialang.org/t/why-must-the-second-argument-of-hash-come-from-another-hash-function/124783)

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**Author:** [@GHTaarn](https://discourse.julialang.org/u/GHTaarn)\
**Replies:** 5\
**Last updated:** [January 15, 2025, 9:34pm UTC](https://discourse.julialang.org/t/why-must-the-second-argument-of-hash-come-from-another-hash-function/124783 "2025-01-15T21:34:35Z")

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The documentation for hash contains an example that has the following comment: # only use the output of another hash function as the second argument What happens if I just provide any UInt64 value as the second argumen…

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## [Debugger - Treat specific functions as compiled in package](https://discourse.julialang.org/t/debugger-treat-specific-functions-as-compiled-in-package/124802)

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**Author:** [@p\_f](https://discourse.julialang.org/u/p_f)\
**Replies:** 0\
**Last updated:** [January 15, 2025, 5:48pm UTC](https://discourse.julialang.org/t/debugger-treat-specific-functions-as-compiled-in-package/124802 "2025-01-15T17:48:02Z")

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Motivated by Extremely slow debugging in VS Code, I have become invested in understanding the VSCode debugger. Is it possible to effectively treat particular functions in my package as compiled? For example, consider …

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## [Julia hanging after producing only a few plots](https://discourse.julialang.org/t/julia-hanging-after-producing-only-a-few-plots/124808)

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**Author:** [@gtk](https://discourse.julialang.org/u/gtk)\
**Replies:** 0\
**Last updated:** [January 15, 2025, 7:06pm UTC](https://discourse.julialang.org/t/julia-hanging-after-producing-only-a-few-plots/124808 "2025-01-15T19:06:16Z")

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Hi! I am currently using VSCode to edit files in a repository through remote development on WSL2. Opening Julia and starting a new REPL is no problem, but after a while I get the following showing up in the REPL: I h…

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## [Core dumped error when differentiating wrt NN parameters using Enzyme](https://discourse.julialang.org/t/core-dumped-error-when-differentiating-wrt-nn-parameters-using-enzyme/124471)

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**Author:** [@dameka](https://discourse.julialang.org/u/dameka)\
**Replies:** 3\
**Last updated:** [January 15, 2025, 5:13pm UTC](https://discourse.julialang.org/t/core-dumped-error-when-differentiating-wrt-nn-parameters-using-enzyme/124471 "2025-01-15T17:13:02Z")

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I’m differentiating a quantity with respect to the parameters of a neural network. I’m getting a “core dumped” error, which is away above my Julia pay grade. The neural network passes through several functions on the wa…

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## [Error using Enzyme to autodiff wrt Flux neural net parameters](https://discourse.julialang.org/t/error-using-enzyme-to-autodiff-wrt-flux-neural-net-parameters/123934)

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**Author:** [@dameka](https://discourse.julialang.org/u/dameka)\
**Replies:** 10\
**Last updated:** [January 15, 2025, 5:11pm UTC](https://discourse.julialang.org/t/error-using-enzyme-to-autodiff-wrt-flux-neural-net-parameters/123934 "2025-01-15T17:11:15Z")

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I’m trying to use Enzyme to autodiff a function with respect to a neural network’s parameters. I’m running into this error: No augmented forward pass found for jl\_genericmemory\_slice at context: %93 = call nonnull "e…

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## [Warning during tests](https://discourse.julialang.org/t/warning-during-tests/124796)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 3\
**Last updated:** [January 15, 2025, 5:04pm UTC](https://discourse.julialang.org/t/warning-during-tests/124796 "2025-01-15T17:04:18Z")

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When I run the tests of KiteModels.jl I get the warning: ┌ Warning: Using a \`Bool\` for keyword argument \`autodiff\` is deprecated. Please use an \`ADType\` specifier. │ caller = \_process\_AD\_choice(ad\_alg::Bool, chunksize…

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