# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1141

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

**Page:** 1142

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## [Quantum Computing Startup, Multiple Roles](https://discourse.julialang.org/t/quantum-computing-startup-multiple-roles/75150)

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**Author:** [@ngemelke](https://discourse.julialang.org/u/ngemelke)\
**Replies:** 2\
**Last updated:** [January 26, 2022, 2:19pm UTC](https://discourse.julialang.org/t/quantum-computing-startup-multiple-roles/75150 "2022-01-26T14:19:24Z")

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QuEra Computing is looking to fill several positions in scientific programming, developers for its cloud service team, and devops. QuEra is a quantum computing startup spun out of research at Harvard and MIT that develop…

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## [NeuralPDE to simulate Burguer 1D - not a satisfactorial solution](https://discourse.julialang.org/t/neuralpde-to-simulate-burguer-1d-not-a-satisfactorial-solution/75229)

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**Author:** [@BuddhiLW](https://discourse.julialang.org/u/BuddhiLW)\
**Replies:** 6\
**Last updated:** [January 26, 2022, 1:56pm UTC](https://discourse.julialang.org/t/neuralpde-to-simulate-burguer-1d-not-a-satisfactorial-solution/75229 "2022-01-26T13:56:02Z")

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I’m writting a research in which I heavily used NeuralPDE.jl, and I would like to showcase solution vs analytical, or classical simulations vs provided by the package. In one of these instances, I’m getting an answer I …

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## [Run parts of other files from a loop](https://discourse.julialang.org/t/run-parts-of-other-files-from-a-loop/75195)

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**Author:** [@alexdmeyer](https://discourse.julialang.org/u/alexdmeyer)\
**Replies:** 9\
**Last updated:** [January 26, 2022, 12:47pm UTC](https://discourse.julialang.org/t/run-parts-of-other-files-from-a-loop/75195 "2022-01-26T12:47:30Z")

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Hi Julia folks, This is a somewhat strange/niche question, but I hope the answer ends up being useful to other users. Basically, I have one file that needs to loop over a list of other files, evaluating only the first f…

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## [Problem using \`\`\`lyapunov spectrum\`\`\`](https://discourse.julialang.org/t/problem-using-lyapunov-spectrum/75224)

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**Author:** [@pafloxy](https://discourse.julialang.org/u/pafloxy)\
**Replies:** 7\
**Last updated:** [January 26, 2022, 1:25pm UTC](https://discourse.julialang.org/t/problem-using-lyapunov-spectrum/75224 "2022-01-26T13:25:40Z")

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the follwing code cannot recognise the lyapunovspectrum function. lyapunovspectrum(ds\_3, 10 ; Ttr= 10.00) Can anyone point out the problem here ?

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## [Why I can't use mul! and plan\_fft together?](https://discourse.julialang.org/t/why-i-cant-use-mul-and-plan-fft-together/75186)

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**Author:** [@liangqimin1998](https://discourse.julialang.org/u/liangqimin1998)\
**Replies:** 4\
**Last updated:** [January 26, 2022, 12:59pm UTC](https://discourse.julialang.org/t/why-i-cant-use-mul-and-plan-fft-together/75186 "2022-01-26T12:59:02Z")

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Hi, I just started to use Julia recently, and when I try to use mul! and plan\_fft to get better performance, I always get a bug that I can’t deal with My input is u0=zeros(nz,nr) for i in 1:nz for j in 1:nr …

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## [Identifying variables in GAMS.jl errors (how do I look up JuMP variables from auto-generated name x..)](https://discourse.julialang.org/t/identifying-variables-in-gams-jl-errors-how-do-i-look-up-jump-variables-from-auto-generated-name-x/74851)

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**Author:** [@MartinBonde](https://discourse.julialang.org/u/MartinBonde)\
**Replies:** 3\
**Last updated:** [January 26, 2022, 12:55pm UTC](https://discourse.julialang.org/t/identifying-variables-in-gams-jl-errors-how-do-i-look-up-jump-variables-from-auto-generated-name-x/74851 "2022-01-26T12:55:19Z")

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I am sending a JuMP model to a GAMS solver using GAMS.jl and get an error/warning: \*\* Error in Square System: A variable tries to exceed its bound. This is perfectly familiar and I get more information by looking in th…

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## [Julia in a game engine, possibly in Unreal (or Godot, or CryEngine...)](https://discourse.julialang.org/t/julia-in-a-game-engine-possibly-in-unreal-or-godot-or-cryengine/75188)

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**Author:** [@Palli](https://discourse.julialang.org/u/Palli)\
**Replies:** 4\
**Last updated:** [January 26, 2022, 10:55am UTC](https://discourse.julialang.org/t/julia-in-a-game-engine-possibly-in-unreal-or-godot-or-cryengine/75188 "2022-01-26T10:55:46Z")

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For simple (2D) games GameZero.jl is available. For AAA (3D) games, Unreal, written in C++ as almost all are, is likely the best game engine out there. And https://godotengine.org/ likely the best open source engine (fa…

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## [HDF5 collective read using MPI goes out of memory, but write works perfectly](https://discourse.julialang.org/t/hdf5-collective-read-using-mpi-goes-out-of-memory-but-write-works-perfectly/75158)

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**Author:** [@Chiil](https://discourse.julialang.org/u/Chiil)\
**Replies:** 9\
**Last updated:** [January 26, 2022, 10:23am UTC](https://discourse.julialang.org/t/hdf5-collective-read-using-mpi-goes-out-of-memory-but-write-works-perfectly/75158 "2022-01-26T10:23:51Z")

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I have a test script that uses parallel HDF5 for reading and writing. I am testing this on a node of our cluster with ample memory available, yet the read goes out of memory. Interestingly, the write allocates only ~200…

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## [\[ANN\] Czoo.jl - project to provide examples of using ccall with Julia and C Code examples - also call for contributors](https://discourse.julialang.org/t/ann-czoo-jl-project-to-provide-examples-of-using-ccall-with-julia-and-c-code-examples-also-call-for-contributors/75034)

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**Author:** [@lawless-m](https://discourse.julialang.org/u/lawless-m)\
**Replies:** 4\
**Last updated:** [January 26, 2022, 9:57am UTC](https://discourse.julialang.org/t/ann-czoo-jl-project-to-provide-examples-of-using-ccall-with-julia-and-c-code-examples-also-call-for-contributors/75034 "2022-01-26T09:57:02Z")

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https://github.com/lawless-m/Czoo.jl The other day I had some questions about using CCALL. While the Julia code was MWE the C code needed 25Gb of data ! As a beginner to interfacing with C libraries I thought I would b…

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## [Defining functions which use other functions](https://discourse.julialang.org/t/defining-functions-which-use-other-functions/75208)

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**Author:** [@Nathan\_Boyer](https://discourse.julialang.org/u/Nathan_Boyer)\
**Replies:** 7\
**Last updated:** [January 26, 2022, 7:11am UTC](https://discourse.julialang.org/t/defining-functions-which-use-other-functions/75208 "2022-01-26T07:11:39Z")

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ΔK(ϕ,λ,Δσ,a,c,Q,f) = λ(ϕ,a,c) \* Δσ \* sqrt(π \* a / Q(a,c)) \* f(ϕ) dadN(λ,Δσ,a,c,Q,f) = ΔK(ϕ=90, ...) Should I include all functions, function inputs, and raw inputs in a higher level function signature, or is it better …

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## [How to properly bisect Julia's git history in search of bugs?](https://discourse.julialang.org/t/how-to-properly-bisect-julias-git-history-in-search-of-bugs/75193)

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**Author:** [@Krastanov](https://discourse.julialang.org/u/Krastanov)\
**Replies:** 3\
**Last updated:** [January 26, 2022, 4:06am UTC](https://discourse.julialang.org/t/how-to-properly-bisect-julias-git-history-in-search-of-bugs/75193 "2022-01-26T04:06:57Z")

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I noticed that current nightly is slower to import packages than 1.7.1. Julia is easy enough to compile from scratch, so I tried to use git bisect to find when that happened. Naively I tried bisecting between v1.7.1 and m…

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## [How to use ForwardDiff with CuArrays](https://discourse.julialang.org/t/how-to-use-forwarddiff-with-cuarrays/39542)

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**Author:** [@clinton](https://discourse.julialang.org/u/clinton)\
**Replies:** 11\
**Last updated:** [January 26, 2022, 3:55am UTC](https://discourse.julialang.org/t/how-to-use-forwarddiff-with-cuarrays/39542 "2022-01-26T03:55:13Z")

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I want to use CuArrays to accelerate a Jacobian calculation for a function \\Re^m \\mapsto \\Re^n where n\>\>m, which seems like a pretty good use case for ForwardDiff. I saw some usage of ForwardDiff in the tests for CuArray…

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## [Flight Dynamic Models](https://discourse.julialang.org/t/flight-dynamic-models/31455)

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**Author:** [@tog](https://discourse.julialang.org/u/tog)\
**Replies:** 15\
**Last updated:** [January 26, 2022, 3:29am UTC](https://discourse.julialang.org/t/flight-dynamic-models/31455 "2022-01-26T03:29:17Z")

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Hi All I am discovering the Julia community after a presentation from a colleagues and it looks amazing. I discovered that there exist a Satellite Toolbox. Is there already an initiative for building a flight dynamics…

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## [Allocation with Union Nothing](https://discourse.julialang.org/t/allocation-with-union-nothing/75163)

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**Author:** [@RomainPct](https://discourse.julialang.org/u/RomainPct)\
**Replies:** 2\
**Last updated:** [January 26, 2022, 1:12am UTC](https://discourse.julialang.org/t/allocation-with-union-nothing/75163 "2022-01-26T01:12:17Z")

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Hello, I discovered this behavior that created some weird allocations in my code. I feel like I get it now, but I would be interested in some relevant comments/explanations. f\_allocates(x) = isempty(x) ? nothing : (0, …

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## [Question About @allocated](https://discourse.julialang.org/t/question-about-allocated/75155)

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**Author:** [@TI36XPro](https://discourse.julialang.org/u/TI36XPro)\
**Replies:** 2\
**Last updated:** [January 26, 2022, 1:11am UTC](https://discourse.julialang.org/t/question-about-allocated/75155 "2022-01-26T01:11:39Z")

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I am observing some behavior and I don’t understand it. I would appreciate any thoughts. For context, I’m using VSCode with the Julia extension, interactively evaluating each line of my code by highlighting it and pressi…

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## [Improving performance of dynamic programming problem of households in a labor market model](https://discourse.julialang.org/t/improving-performance-of-dynamic-programming-problem-of-households-in-a-labor-market-model/74892)

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**Author:** [@Mario\_Silva](https://discourse.julialang.org/u/Mario_Silva)\
**Replies:** 25\
**Last updated:** [January 26, 2022, 12:13am UTC](https://discourse.julialang.org/t/improving-performance-of-dynamic-programming-problem-of-households-in-a-labor-market-model/74892 "2022-01-26T00:13:04Z")

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Greetings: I am working on solving a heterogeneous-agent economics model in Julia. The most demanding part is solving the household problem using dynamic programming. Households can be either employed or unemployed. The…

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## [How to reference JuMP constraint from solver index?](https://discourse.julialang.org/t/how-to-reference-jump-constraint-from-solver-index/57865)

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**Author:** [@claytonpbarrows](https://discourse.julialang.org/u/claytonpbarrows)\
**Replies:** 6\
**Last updated:** [January 25, 2022, 10:29pm UTC](https://discourse.julialang.org/t/how-to-reference-jump-constraint-from-solver-index/57865 "2022-01-25T22:29:35Z")

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Some solvers will indicate the constraints causing infeasibilities (e.g. Gurobi, Xpress, …) like this: User MIP start violates constraint R33048 by 0.493000000 Is there a way to retrieve the JuMP constraint ref corresp…

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## [Vscode: tag new version failing](https://discourse.julialang.org/t/vscode-tag-new-version-failing/73456)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 2\
**Last updated:** [January 25, 2022, 9:54pm UTC](https://discourse.julialang.org/t/vscode-tag-new-version-failing/73456 "2022-01-25T21:54:08Z")

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I am getting this error when using the “tag new version” feature of the VSCode extension: ┌ Warning: The active manifest file is an older format with no julia version entry. Dependencies may have been resolved with a d…

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## [Undetected numerical issues with GLPK](https://discourse.julialang.org/t/undetected-numerical-issues-with-glpk/75196)

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**Author:** [@sstroemer](https://discourse.julialang.org/u/sstroemer)\
**Replies:** 1\
**Last updated:** [January 25, 2022, 9:48pm UTC](https://discourse.julialang.org/t/undetected-numerical-issues-with-glpk/75196 "2022-01-25T21:48:32Z")

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I’ve ran across an issue in some unit tests (of a JuMP model), that were hard to track down. Those are only using GLPK since that is easy to integrate into the testing. I noticed that models with numerical issues seem to…

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## [Call julia function from python](https://discourse.julialang.org/t/call-julia-function-from-python/75202)

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**Author:** [@xspeng](https://discourse.julialang.org/u/xspeng)\
**Replies:** 2\
**Last updated:** [January 25, 2022, 9:48pm UTC](https://discourse.julialang.org/t/call-julia-function-from-python/75202 "2022-01-25T21:48:24Z")

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Hi, guys, I use bayesion optimization of python plus subfunction of julia to do my simulation, and I can successfully run the simple function see here, maybe I should ask another question, if I want to combine the speed…

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## [How to pass colors from xcolor in pgfplotsx?](https://discourse.julialang.org/t/how-to-pass-colors-from-xcolor-in-pgfplotsx/75190)

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**Author:** [@ccmejia](https://discourse.julialang.org/u/ccmejia)\
**Replies:** 1\
**Last updated:** [January 25, 2022, 9:42pm UTC](https://discourse.julialang.org/t/how-to-pass-colors-from-xcolor-in-pgfplotsx/75190 "2022-01-25T21:42:07Z")

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Hi there, I am trying to pass color name from xcolor latex package, for example the “NavyBlue” color. However, it seems that “NavyBlue” or any other “special” color is not recognized: Package xcolor Error: Undefined col…

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## [Unmatched dimensions for 3D plot](https://discourse.julialang.org/t/unmatched-dimensions-for-3d-plot/75180)

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**Author:** [@BuddhiLW](https://discourse.julialang.org/u/BuddhiLW)\
**Replies:** 14\
**Last updated:** [January 25, 2022, 8:48pm UTC](https://discourse.julialang.org/t/unmatched-dimensions-for-3d-plot/75180 "2022-01-25T20:48:00Z")

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I have a program to solve 1D Burguer’s equation. I have the following values/dimensions, which are giving me a dimensional error. I don’t understand what is going wrong. If anyone can help me, I appreciate it. julia\> si…

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## [JuMP nonlinear optimization constraints broken to O(1e-9)](https://discourse.julialang.org/t/jump-nonlinear-optimization-constraints-broken-to-o-1e-9/75182)

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**Author:** [@Kevin\_Shen1](https://discourse.julialang.org/u/Kevin_Shen1)\
**Replies:** 7\
**Last updated:** [January 25, 2022, 7:51pm UTC](https://discourse.julialang.org/t/jump-nonlinear-optimization-constraints-broken-to-o-1e-9/75182 "2022-01-25T19:51:51Z")

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I’m running nonlinear optimization using the Ipopt optimizer. My objective/cost function relies on the constraints being adhered to strictly. However on some iterations the constraint are being broken. Specifically, my …

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## [Missing functions in Zygote](https://discourse.julialang.org/t/missing-functions-in-zygote/75187)

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**Author:** [@jsbyrnes](https://discourse.julialang.org/u/jsbyrnes)\
**Replies:** 6\
**Last updated:** [January 25, 2022, 6:55pm UTC](https://discourse.julialang.org/t/missing-functions-in-zygote/75187 "2022-01-25T18:55:57Z")

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I am trying to use the jacobian functions in Zygote, but I can’t find them. In what has to be the dumbest questions ever posted here, there’s very little in Zygote for me. Heres the problem: julia\> using Zygote julia\> …

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## [Precompilation does not see added dependecy](https://discourse.julialang.org/t/precompilation-does-not-see-added-dependecy/75192)

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**Author:** [@Gregstrq](https://discourse.julialang.org/u/Gregstrq)\
**Replies:** 0\
**Last updated:** [January 25, 2022, 5:52pm UTC](https://discourse.julialang.org/t/precompilation-does-not-see-added-dependecy/75192 "2022-01-25T17:52:21Z")

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I have added “Infiltrator” as a dependency to my locally developed package “SpinGauss”. However, it produced an error at precompilation stage. When I run import Pkg; Pkg.precompile() as suggested by the error log, I ge…

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## [Question about any possible text manipulation tools for 'fine-tuning' introspection (reflection) output](https://discourse.julialang.org/t/question-about-any-possible-text-manipulation-tools-for-fine-tuning-introspection-reflection-output/75175)

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**Author:** [@maxild](https://discourse.julialang.org/u/maxild)\
**Replies:** 6\
**Last updated:** [January 25, 2022, 5:38pm UTC](https://discourse.julialang.org/t/question-about-any-possible-text-manipulation-tools-for-fine-tuning-introspection-reflection-output/75175 "2022-01-25T17:38:27Z")

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Is it possible to use some kind of ‘pattern/string match’ in the REPL when inspecting dispatch tables of functions with hundreds of methods. Like… methods(convert) | grep 'some pattern like \<: Number or :\> Number' I …

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## [Backpropagating through orthogonal projection operator](https://discourse.julialang.org/t/backpropagating-through-orthogonal-projection-operator/63083)

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**Author:** [@rkube](https://discourse.julialang.org/u/rkube)\
**Replies:** 2\
**Last updated:** [January 25, 2022, 5:32pm UTC](https://discourse.julialang.org/t/backpropagating-through-orthogonal-projection-operator/63083 "2022-01-25T17:32:34Z")

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Hi, I have a neural network whose loss functions requires to calculate orthogonal projections onto the output of the network. The code runs fine on the CPU, albeit slow. Porting it to the GPU is difficult and I’m stuck.…

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## [Best way to install julia with CLI on linux enviroment?](https://discourse.julialang.org/t/best-way-to-install-julia-with-cli-on-linux-enviroment/75151)

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**Author:** [@rmsmsgood](https://discourse.julialang.org/u/rmsmsgood)\
**Replies:** 3\
**Last updated:** [January 25, 2022, 4:51pm UTC](https://discourse.julialang.org/t/best-way-to-install-julia-with-cli-on-linux-enviroment/75151 "2022-01-25T16:51:09Z")

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Recently, i am interested in distributed computing and spend much time for install julia on our servers. But as i know, the installation of julia with CLI is very inconvenient until now. I want command like below can in…

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## [Makie.jl - How can I have a label on top of an image plot?](https://discourse.julialang.org/t/makie-jl-how-can-i-have-a-label-on-top-of-an-image-plot/74536)

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**Author:** [@klafyvel](https://discourse.julialang.org/u/klafyvel)\
**Replies:** 2\
**Last updated:** [January 25, 2022, 4:39pm UTC](https://discourse.julialang.org/t/makie-jl-how-can-i-have-a-label-on-top-of-an-image-plot/74536 "2022-01-25T16:39:28Z")

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Hi, I am trying to label some plots containing images, but somehow I fail to have a label on top of an image. Here is a minimal working example : using GLMakie, FileIO img = load(assetpath("cow.png")) f = Figure() imag…

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## [No idea what a crash report means](https://discourse.julialang.org/t/no-idea-what-a-crash-report-means/75172)

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**Author:** [@linkz](https://discourse.julialang.org/u/linkz)\
**Replies:** 1\
**Last updated:** [January 25, 2022, 3:18pm UTC](https://discourse.julialang.org/t/no-idea-what-a-crash-report-means/75172 "2022-01-25T15:18:04Z")

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Hello all, I am using Flux, DiffEqFlux and DifferentialEquations to train a custom model involving neural ODEs. I recently moved from Julia 1.6.3 to Julia 1.7.1. In 1.6.3 used to train a relatively simpler version of th…

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