# Latest

**URL:** https://discourse.julialang.org/latest.md?page=658

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

**Page:** 659

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## [Efficient simulation of spatially coupled ODEs on arbitrary graphs](https://discourse.julialang.org/t/efficient-simulation-of-spatially-coupled-odes-on-arbitrary-graphs/100852)

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**Author:** [@johannesnauta](https://discourse.julialang.org/u/johannesnauta)\
**Replies:** 5\
**Last updated:** [June 29, 2023, 9:00pm UTC](https://discourse.julialang.org/t/efficient-simulation-of-spatially-coupled-odes-on-arbitrary-graphs/100852 "2023-06-29T21:00:37Z")

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I know this question is not very specific, but I would like to check whether there are existing approaches for simulating coupled ODEs on nodes of (arbitrarily large) graphs/networks with diffusion between the nodes. Loo…

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## [Computing expectation of nonlinear function of multinomial logit](https://discourse.julialang.org/t/computing-expectation-of-nonlinear-function-of-multinomial-logit/80575)

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**Author:** [@samerb](https://discourse.julialang.org/u/samerb)\
**Replies:** 4\
**Last updated:** [June 29, 2023, 6:03pm UTC](https://discourse.julialang.org/t/computing-expectation-of-nonlinear-function-of-multinomial-logit/80575 "2023-06-29T18:03:25Z")

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Suppose I have constants \\{\\delta\_j\\}\_{j \\in J} and have random variables \\{\\varepsilon\_j\\}\_{j\\in J} distributed iid according to type I extreme value distribution as in a standard multinomial logit model. Let F: \\mathbb…

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## [Differentiating Jacobian-vector product for sliced score matching?](https://discourse.julialang.org/t/differentiating-jacobian-vector-product-for-sliced-score-matching/99746)

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**Author:** [@Red-Portal](https://discourse.julialang.org/u/Red-Portal)\
**Replies:** 18\
**Last updated:** [June 29, 2023, 5:56pm UTC](https://discourse.julialang.org/t/differentiating-jacobian-vector-product-for-sliced-score-matching/99746 "2023-06-29T17:56:47Z")

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Hi, I’m trying to implement score matching in Julia. Essentially, one needs to differentiate through the expression: \\mathbb{E}\_{v \\sim \\mathcal{N}(0,\\mathbf{I})} \\mathbb{E}\_{x \\sim p(x)} \\left( v^{\\top} \\nabla\_x f(x; …

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## [Getting IJulia to work inside of a mamba venv](https://discourse.julialang.org/t/getting-ijulia-to-work-inside-of-a-mamba-venv/100977)

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**Author:** [@anon56682678](https://discourse.julialang.org/u/anon56682678)\
**Replies:** 4\
**Last updated:** [June 29, 2023, 5:27pm UTC](https://discourse.julialang.org/t/getting-ijulia-to-work-inside-of-a-mamba-venv/100977 "2023-06-29T17:27:09Z")

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I am having trouble installing IJulia in Julia 1.9.1 inside a mamba environment. The crux of the issue seems to be the compiler not being able to find MbedTLS even though it is installed Looking for: \['mbedtls'\] conda-…

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## [Take positive part of weights in loss function](https://discourse.julialang.org/t/take-positive-part-of-weights-in-loss-function/100950)

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**Author:** [@clairem](https://discourse.julialang.org/u/clairem)\
**Replies:** 3\
**Last updated:** [June 29, 2023, 5:18pm UTC](https://discourse.julialang.org/t/take-positive-part-of-weights-in-loss-function/100950 "2023-06-29T17:18:07Z")

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Hi! I’m trying to constrain my weights matrix to contain only positive values. I was confused by answers to similar questions, and I thought it might make sense to implement my loss function such that, when it takes my …

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## [Request: call for NeurIPS ethics reviewers](https://discourse.julialang.org/t/request-call-for-neurips-ethics-reviewers/100984)

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**Author:** [@jiahao](https://discourse.julialang.org/u/jiahao)\
**Replies:** 0\
**Last updated:** [June 29, 2023, 3:50pm UTC](https://discourse.julialang.org/t/request-call-for-neurips-ethics-reviewers/100984 "2023-06-29T15:50:35Z")

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NeurIPS is seeking ethics reviewers, particularly in the areas of: a) Human rights and inappropriate potential applications, and b) Security and privacy. Call: NeurIPS 2023 Sign-up: NeurIPS 2023 Ethics Reviewer Invit…

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## [Define geometry for NeuralPDE?](https://discourse.julialang.org/t/define-geometry-for-neuralpde/100921)

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**Author:** [@rkube](https://discourse.julialang.org/u/rkube)\
**Replies:** 6\
**Last updated:** [June 29, 2023, 3:50pm UTC](https://discourse.julialang.org/t/define-geometry-for-neuralpde/100921 "2023-06-29T15:50:13Z")

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Hi, I’m looking into solving PDEs on a 2d domain using PINNs and would like to try the NeuralPDE package. Is there a way to define a custom geometry besides linear intervals? I can’t find it in the documentation, the e…

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## [DiffEqFlux.sciml\_train](https://discourse.julialang.org/t/diffeqflux-sciml-train/100814)

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**Author:** [@Maria\_Adelaide\_Loffa](https://discourse.julialang.org/u/Maria_Adelaide_Loffa)\
**Replies:** 4\
**Last updated:** [June 29, 2023, 2:58pm UTC](https://discourse.julialang.org/t/diffeqflux-sciml-train/100814 "2023-06-29T14:58:01Z")

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Hi, I am new to Julia and lately I was studying some examples about NeuralODEs. In many of the, “DiffEqFlux.sciml\_train” it’s used, but I am not able to run it, and i get and error about “method matching”. Even by copy…

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## [Remove top or bottom axis in :box plot](https://discourse.julialang.org/t/remove-top-or-bottom-axis-in-box-plot/100897)

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**Author:** [@cmdenis](https://discourse.julialang.org/u/cmdenis)\
**Replies:** 6\
**Last updated:** [June 29, 2023, 12:31pm UTC](https://discourse.julialang.org/t/remove-top-or-bottom-axis-in-box-plot/100897 "2023-06-29T12:31:40Z")

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Hi there, I’ve been searching for a way of doing this, but cannot find anything… I’ve been trying to make a box plot but with a missing axis. Essentially, I would like to get the results given by plot(framestyle = :bo…

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## [Lazy Constraints on MIP problems](https://discourse.julialang.org/t/lazy-constraints-on-mip-problems/100969)

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**Author:** [@Ignacio](https://discourse.julialang.org/u/Ignacio)\
**Replies:** 2\
**Last updated:** [June 29, 2023, 12:18pm UTC](https://discourse.julialang.org/t/lazy-constraints-on-mip-problems/100969 "2023-06-29T12:18:42Z")

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Hello all, I am trying trying to solve the following MIP with the Xpress solver (and I’ve also tried it with the GLPK solver) with lazy constraint. Variables of interest are x and y (non-integer), integer variable z is …

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## [Backward SDE StochasticDiffEq](https://discourse.julialang.org/t/backward-sde-stochasticdiffeq/100952)

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**Author:** [@mleprovost](https://discourse.julialang.org/u/mleprovost)\
**Replies:** 2\
**Last updated:** [June 29, 2023, 11:18am UTC](https://discourse.julialang.org/t/backward-sde-stochasticdiffeq/100952 "2023-06-29T11:18:01Z")

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Hello, I am interested in solving backward SDEs as in these papers (https://arxiv.org/pdf/2011.13456.pdf, https://papers.nips.cc/paper/2021/file/0a9fdbb17feb6ccb7ec405cfb85222c4-Paper.pdf). They talk about standard Wien…

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## [N\_adapt in NUTS()](https://discourse.julialang.org/t/n-adapt-in-nuts/100967)

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**Author:** [@Sahil\_Khan](https://discourse.julialang.org/u/Sahil_Khan)\
**Replies:** 0\
**Last updated:** [June 29, 2023, 9:01am UTC](https://discourse.julialang.org/t/n-adapt-in-nuts/100967 "2023-06-29T09:01:49Z")

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What happens if we keep n\_adapts = 0? Does it has any bad effect on whole inference or its just not giving initial burnin which you can give later manually after obtaining chain or is it something else?

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## [Heat-diffusion equation boundary condition](https://discourse.julialang.org/t/heat-diffusion-equation-boundary-condition/100592)

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**Author:** [@Reza\_AO](https://discourse.julialang.org/u/Reza_AO)\
**Replies:** 7\
**Last updated:** [June 29, 2023, 8:48am UTC](https://discourse.julialang.org/t/heat-diffusion-equation-boundary-condition/100592 "2023-06-29T08:48:39Z")

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Hi I want to solve a 1 dimensional heat diffusion equation. At the right side of my domain I got the convective boundary condition; #Tamb, Kl,h are constants h \* (T(t, Le) - Tamb) - kl \* Dx(T(t, 0)) ~ 0 When I solv…

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## [LIBSVM.jl is broken?](https://discourse.julialang.org/t/libsvm-jl-is-broken/100958)

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**Author:** [@JunDamin](https://discourse.julialang.org/u/JunDamin)\
**Replies:** 4\
**Last updated:** [June 29, 2023, 6:49am UTC](https://discourse.julialang.org/t/libsvm-jl-is-broken/100958 "2023-06-29T06:49:05Z")

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I am using LIBSVM.jl in julia 1.9.1. When I follow through algebra of graphics tutorial, julia crashed whenever I run fit! function with model. I tried many options like uninstalled and reinstall libsvm.jl, it still no…

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## [How to get value of ticks?](https://discourse.julialang.org/t/how-to-get-value-of-ticks/100938)

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**Author:** [@panbroggi](https://discourse.julialang.org/u/panbroggi)\
**Replies:** 2\
**Last updated:** [June 29, 2023, 6:44am UTC](https://discourse.julialang.org/t/how-to-get-value-of-ticks/100938 "2023-06-29T06:44:13Z")

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Hi everyone, I am trying to get the value of the ticks in a plot, but they appear to change before showing the plot. The function prints Float32\[0, 5, 10\] while the actual ticks are \[0; 0.5; 1.0\]. using GLMakie fig, a…

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## [The applicable method may be too new: running in world age 32335, while current world is 32342](https://discourse.julialang.org/t/the-applicable-method-may-be-too-new-running-in-world-age-32335-while-current-world-is-32342/100949)

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**Author:** [@parssh](https://discourse.julialang.org/u/parssh)\
**Replies:** 4\
**Last updated:** [June 29, 2023, 3:59am UTC](https://discourse.julialang.org/t/the-applicable-method-may-be-too-new-running-in-world-age-32335-while-current-world-is-32342/100949 "2023-06-29T03:59:01Z")

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Hi, Can you help me fix this, I am trying to run this as a loop for 10 fits (not showing the whole loop code). But currently I am failing on just one loop itself. The inspect function (only within Pumas Package) fails t…

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## [JSON3.jl layer for HTTP.jl](https://discourse.julialang.org/t/json3-jl-layer-for-http-jl/100678)

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**Author:** [@mkitti](https://discourse.julialang.org/u/mkitti)\
**Replies:** 3\
**Last updated:** [June 22, 2023, 7:52am UTC](https://discourse.julialang.org/t/json3-jl-layer-for-http-jl/100678 "2023-06-22T07:52:19Z")

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I was playing with some JSON based REST APIs, and I was starting to get tired of typing JSON3.read(response.body) all the time, so I came up with the following layer. julia\> module HTTPJSON3 import HTTP, JSON…

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## [\[Workgroup\] JuliaHealth Meeting -- June 30th, 2023](https://discourse.julialang.org/t/workgroup-juliahealth-meeting-june-30th-2023/100620)

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**Author:** [@TheCedarPrince](https://discourse.julialang.org/u/TheCedarPrince)\
**Replies:** 1\
**Last updated:** [June 29, 2023, 1:46am UTC](https://discourse.julialang.org/t/workgroup-juliahealth-meeting-june-30th-2023/100620 "2023-06-29T01:46:10Z")

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Hi folks, The next JuliaHealth meeting is happening next Friday June 30th, 2023 from 10 - 11AM EST! So far, I imagine this as our agenda: New member welcomes! Planning JuliaHealth Birds of a Feather Topics? Facilitat…

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## [Dual Variable](https://discourse.julialang.org/t/dual-variable/100934)

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**Author:** [@Gagan\_Meena](https://discourse.julialang.org/u/Gagan_Meena)\
**Replies:** 2\
**Last updated:** [June 29, 2023, 12:52am UTC](https://discourse.julialang.org/t/dual-variable/100934 "2023-06-29T00:52:37Z")

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using JuMP, Gurobi include("Data.jl") UnitCommitment\_dt = UC\_dt function DUC\_Clearing(UnitCommitment\_dt) # Indices ngen = length(UC\_dt.Gen\_Constraints\[:,1\]) periods = length(UC\_dt.Forecast\[1,:\]) # Sets…

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## [Assemble vector in 2d testspace](https://discourse.julialang.org/t/assemble-vector-in-2d-testspace/100945)

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**Author:** [@mary](https://discourse.julialang.org/u/mary)\
**Replies:** 0\
**Last updated:** [June 28, 2023, 8:05pm UTC](https://discourse.julialang.org/t/assemble-vector-in-2d-testspace/100945 "2023-06-28T20:05:24Z")

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Hi all i have a simple question. i really appreciate your help. i want to assemble linear vector of weak form and my testfespace in 2d but it gives me error. do you know how can i solve this? order = 1 reffe\_Disp = Ref…

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## [BSON.load(filename,@\_\_MODULE\_\_) doesn't work inside a Test Module](https://discourse.julialang.org/t/bson-load-filename-module-doesnt-work-inside-a-test-module/100955)

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**Author:** [@Allan\_Baker](https://discourse.julialang.org/u/Allan_Baker)\
**Replies:** 0\
**Last updated:** [June 29, 2023, 12:41am UTC](https://discourse.julialang.org/t/bson-load-filename-module-doesnt-work-inside-a-test-module/100955 "2023-06-29T00:41:18Z")

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I have a Module. Inside that module I have a BSON.@save and a BSON.load which takes care of saving a struct to and from disk. The function that calls the BSON.load(filename,@MODULE) works fine if called by REPL/Main, o…

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## [Displaying images in a grid layout?](https://discourse.julialang.org/t/displaying-images-in-a-grid-layout/100919)

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**Author:** [@amca01](https://discourse.julialang.org/u/amca01)\
**Replies:** 3\
**Last updated:** [June 29, 2023, 12:06am UTC](https://discourse.julialang.org/t/displaying-images-in-a-grid-layout/100919 "2023-06-29T00:06:29Z")

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What I’m after is a Julia equivalent to Matlab’s “subplots”, that allows images to be displayed in arbitrary grids. I can “stitch” two images of the same size with \[img1 img2\] as the last line of an IJulia cell. But …

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## [How do I check if a specific element in a sparse matrix is defined? (where the matrix possibly have 0-valued entries)](https://discourse.julialang.org/t/how-do-i-check-if-a-specific-element-in-a-sparse-matrix-is-defined-where-the-matrix-possibly-have-0-valued-entries/100947)

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**Author:** [@Torkel](https://discourse.julialang.org/u/Torkel)\
**Replies:** 2\
**Last updated:** [June 28, 2023, 8:41pm UTC](https://discourse.julialang.org/t/how-do-i-check-if-a-specific-element-in-a-sparse-matrix-is-defined-where-the-matrix-possibly-have-0-valued-entries/100947 "2023-06-28T20:41:21Z")

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I have a sparse 2x2 matrix: using SparseArrays sm = SparseMatrixCSC(2, 2, \[1, 3, 4\], \[1, 2, 1\], \[1.0, 0.0, 1.0\]) that looks like: 1.0 1.0 0.0 ⋅ is there a way to check whenever element \[2,2\] is filled or not? N…

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## [Why differentiate between single-element collections and their contents?](https://discourse.julialang.org/t/why-differentiate-between-single-element-collections-and-their-contents/100937)

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**Author:** [@Bizzi](https://discourse.julialang.org/u/Bizzi)\
**Replies:** 8\
**Last updated:** [June 28, 2023, 7:48pm UTC](https://discourse.julialang.org/t/why-differentiate-between-single-element-collections-and-their-contents/100937 "2023-06-28T19:48:26Z")

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Not complaining, just curious (really!) Given the strong influence Matlab has had on Julia’s development, I was surprised to find that 1., \[1.\] and (1.,) were treated as different objects. In my specific use case, this …

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## [Problem with scoping in iteration of function evaluation](https://discourse.julialang.org/t/problem-with-scoping-in-iteration-of-function-evaluation/100886)

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**Author:** [@gmazeine](https://discourse.julialang.org/u/gmazeine)\
**Replies:** 4\
**Last updated:** [June 28, 2023, 6:31pm UTC](https://discourse.julialang.org/t/problem-with-scoping-in-iteration-of-function-evaluation/100886 "2023-06-28T18:31:36Z")

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I have a function (call it feval) that takes a function guess as an argument, and outputs a new function. I want to iterate on this function until a convergence criterion is met. I am struggling to update the guessed fun…

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## [Timed wait for key press](https://discourse.julialang.org/t/timed-wait-for-key-press/100856)

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**Author:** [@Jim](https://discourse.julialang.org/u/Jim)\
**Replies:** 14\
**Last updated:** [June 28, 2023, 5:36pm UTC](https://discourse.julialang.org/t/timed-wait-for-key-press/100856 "2023-06-28T17:36:26Z")

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I am new to Julia but I can’t seem to find out how to do this… I want a function that allows an input of number of seconds to wait for a key to be pressed, if zero it returns the next key pressed in the buffer. Then it …

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## [UndefVarError: ComponentArray not defined](https://discourse.julialang.org/t/undefvarerror-componentarray-not-defined/100884)

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**Author:** [@Marco\_Nesta](https://discourse.julialang.org/u/Marco_Nesta)\
**Replies:** 10\
**Last updated:** [June 28, 2023, 3:54pm UTC](https://discourse.julialang.org/t/undefvarerror-componentarray-not-defined/100884 "2023-06-28T15:54:02Z")

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using Lux, DiffEqFlux, DifferentialEquations, Optimization, OptimizationOptimJL, Random, Plots rng = Random.default\_rng() u0 = Float32\[1.0, 1.0\] datasize = 80 tspan = (0.0f0, 10f0) tsteps = range(tspan\[1\], tspan\[2\],…

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## [Automatically Discover Missing Physics by Embedding Machine Learning into Differential Equations](https://discourse.julialang.org/t/automatically-discover-missing-physics-by-embedding-machine-learning-into-differential-equations/100928)

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**Author:** [@Marco\_Nesta](https://discourse.julialang.org/u/Marco_Nesta)\
**Replies:** 2\
**Last updated:** [June 28, 2023, 3:18pm UTC](https://discourse.julialang.org/t/automatically-discover-missing-physics-by-embedding-machine-learning-into-differential-equations/100928 "2023-06-28T15:18:56Z")

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Automatically Discover Missing Physics by Embedding Machine Learning into Differential Equations · Overview of Julia’s SciML I used the same code from this link, but the results are not the same as in the link.

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## [Creating AD-friendly functions](https://discourse.julialang.org/t/creating-ad-friendly-functions/100914)

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**Author:** [@Bizzi](https://discourse.julialang.org/u/Bizzi)\
**Replies:** 2\
**Last updated:** [June 28, 2023, 3:16pm UTC](https://discourse.julialang.org/t/creating-ad-friendly-functions/100914 "2023-06-28T15:16:26Z")

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Hello everyone. I’m in the process of creating a chained composition of functions, similar to a Flux or Lux network, which I’ll later differentiate for the purpose of solving differential equations. Following the discus…

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## [\[ANN\] DeprecateKeywords.jl – a macro for keyword deprecation](https://discourse.julialang.org/t/ann-deprecatekeywords-jl-a-macro-for-keyword-deprecation/100926)

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**Author:** [@MilesCranmer](https://discourse.julialang.org/u/MilesCranmer)\
**Replies:** 4\
**Last updated:** [June 28, 2023, 2:26pm UTC](https://discourse.julialang.org/t/ann-deprecatekeywords-jl-a-macro-for-keyword-deprecation/100926 "2023-06-28T14:26:00Z")

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DeprecateKeywords.jl DeprecateKeywords.jl is a tiny package (77 lines) which defines a macro @depkws for keyword deprecation. (I wasn’t sure if I should even post this since it’s such a tiny macro, but I thought I migh…

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