# Latest

**URL:** https://discourse.julialang.org/latest.md?page=534

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

**Page:** 535

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## [Iterative construction of lazy Iterators leads to excessive compilation time](https://discourse.julialang.org/t/iterative-construction-of-lazy-iterators-leads-to-excessive-compilation-time/106766)

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**Author:** [@\_cao](https://discourse.julialang.org/u/_cao)\
**Replies:** 21\
**Last updated:** [December 10, 2023, 8:19pm UTC](https://discourse.julialang.org/t/iterative-construction-of-lazy-iterators-leads-to-excessive-compilation-time/106766 "2023-12-10T20:19:00Z")

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I wanted to write an iterator that lazily traverses a graph in breadth first search order, where the graph is defined implicitly by a function giving for each vertex an iterable over the adjacent vertices. This is what I…

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## [The JuliaCon 2024 CFP deadline for Mini-Symposia is Friday, 15th December, 23:59 CET](https://discourse.julialang.org/t/the-juliacon-2024-cfp-deadline-for-mini-symposia-is-friday-15th-december-23-59-cet/107384)

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**Author:** [@Steven\_Kell](https://discourse.julialang.org/u/Steven_Kell)\
**Replies:** 0\
**Last updated:** [December 10, 2023, 6:56pm UTC](https://discourse.julialang.org/t/the-juliacon-2024-cfp-deadline-for-mini-symposia-is-friday-15th-december-23-59-cet/107384 "2023-12-10T18:56:22Z")

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The JuliaCon 2024 CFP deadline for Mini-Symposia is Friday, 15th December, 23:59 CET. Please submit your ideas on pretalx #julialang #DataScience #conference

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## [How to correctly reach a Sagemaker endpoint with AWS.jl](https://discourse.julialang.org/t/how-to-correctly-reach-a-sagemaker-endpoint-with-aws-jl/107380)

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**Author:** [@Simone\_Gabbriellini](https://discourse.julialang.org/u/Simone_Gabbriellini)\
**Replies:** 0\
**Last updated:** [December 10, 2023, 4:26pm UTC](https://discourse.julialang.org/t/how-to-correctly-reach-a-sagemaker-endpoint-with-aws-jl/107380 "2023-12-10T16:26:20Z")

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I am using AWS.jl to call from my machine a Sagemaker endpoint I have on AWS like this: using JSON using AWS: @service @service Sagemaker\_Runtime; body = Dict(:inputs =\> "what is Python?", :parameters =\> Dict( :max\_new…

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## [How to convert an ODESystem to NonlinearSystem?](https://discourse.julialang.org/t/how-to-convert-an-odesystem-to-nonlinearsystem/91079)

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**Author:** [@wangyunyueyueniao](https://discourse.julialang.org/u/wangyunyueyueniao)\
**Replies:** 8\
**Last updated:** [December 10, 2023, 2:31pm UTC](https://discourse.julialang.org/t/how-to-convert-an-odesystem-to-nonlinearsystem/91079 "2023-12-10T14:31:46Z")

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I know there is a “convert\_system” function which can convert a “NonlinearSystem” to an “ODESystem”. Can we do it backwards? So that we can have both steady-state and dynamic simulation with a single code base.

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## [AWS and sign\_aws4 request made with HTTP](https://discourse.julialang.org/t/aws-and-sign-aws4-request-made-with-http/107370)

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**Author:** [@Simone\_Gabbriellini](https://discourse.julialang.org/u/Simone_Gabbriellini)\
**Replies:** 19\
**Last updated:** [December 10, 2023, 2:29pm UTC](https://discourse.julialang.org/t/aws-and-sign-aws4-request-made-with-http/107370 "2023-12-10T14:29:42Z")

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I am trying to autenticate a request to my AWS endpoint using AWS Signature 4, I see there’s a function in AWS.jl called sign\_aws4!, but I would appreciate a code example of how to use it, because I don’t really understa…

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## [Can this type of integro-differential equation be solved somewhere?](https://discourse.julialang.org/t/can-this-type-of-integro-differential-equation-be-solved-somewhere/107286)

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**Author:** [@lrnv](https://discourse.julialang.org/u/lrnv)\
**Replies:** 2\
**Last updated:** [December 10, 2023, 1:01pm UTC](https://discourse.julialang.org/t/can-this-type-of-integro-differential-equation-be-solved-somewhere/107286 "2023-12-10T13:01:24Z")

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Hey, I admit that I am a novice in differential equations solving, this problem came out of completely somthing else… I want to solve an equation that has the following form : S(t) = \\exp(- H(t)) \\partial H(t) = F(t,…

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## [GPU Compilation error when using Lux framework in NeuralPDE](https://discourse.julialang.org/t/gpu-compilation-error-when-using-lux-framework-in-neuralpde/107076)

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**Author:** [@Aakhash\_Sundaresan](https://discourse.julialang.org/u/Aakhash_Sundaresan)\
**Replies:** 13\
**Last updated:** [December 10, 2023, 12:58pm UTC](https://discourse.julialang.org/t/gpu-compilation-error-when-using-lux-framework-in-neuralpde/107076 "2023-12-10T12:58:57Z")

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ERROR: LoadError: GPU compilation of MethodInstance for (::GPUArrays.var"#broadcast\_kernel#26")(::CUDA.CuKernelContext, ::CuDeviceMatrix{Float32, 1}, ::Base.Broadcast.Broadcasted{CUDA.CuArrayStyle{2}, Tuple{Base.OneTo{In…

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## [Where do I report possible errors in documentation?](https://discourse.julialang.org/t/where-do-i-report-possible-errors-in-documentation/107375)

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**Author:** [@chandra](https://discourse.julialang.org/u/chandra)\
**Replies:** 3\
**Last updated:** [December 10, 2023, 12:31pm UTC](https://discourse.julialang.org/t/where-do-i-report-possible-errors-in-documentation/107375 "2023-12-10T12:31:53Z")

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“However, despite integration being an algorithmic procedure, integration is not.” at https://docs.juliahub.com/CalculusWithJulia/AZHbv/0.0.5/integrals/partial\_fractions.html# probably should read However, despite d…

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## [Evaluating constraints at fixed points (and extracting their variables) in JuMP](https://discourse.julialang.org/t/evaluating-constraints-at-fixed-points-and-extracting-their-variables-in-jump/47227)

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**Author:** [@1ozturkbe](https://discourse.julialang.org/u/1ozturkbe)\
**Replies:** 5\
**Last updated:** [December 10, 2023, 3:47am UTC](https://discourse.julialang.org/t/evaluating-constraints-at-fixed-points-and-extracting-their-variables-in-jump/47227 "2023-12-10T03:47:44Z")

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Hello folks, I know this has likely been addressed in a really deep thread here somewhere, but I have been having trouble evaluating constraints in JuMP for fixed variable values. So far, I am doing the following: # Wo…

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## [Parametric struct with key arguments](https://discourse.julialang.org/t/parametric-struct-with-key-arguments/107374)

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**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 1\
**Last updated:** [December 10, 2023, 3:16am UTC](https://discourse.julialang.org/t/parametric-struct-with-key-arguments/107374 "2023-12-10T03:16:17Z")

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struct SortedParticleList{N,M,T\<:Unsigned} storage::SVector{N,T} end Here we have a parametric struct with three position arguments. I can have SortedParticleList{N} and SortedParticleList{N, M} and SortedParti…

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## [Thread safe buffer which blocks retrieval when empty?](https://discourse.julialang.org/t/thread-safe-buffer-which-blocks-retrieval-when-empty/107352)

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**Author:** [@tamasgal](https://discourse.julialang.org/u/tamasgal)\
**Replies:** 11\
**Last updated:** [December 9, 2023, 11:16pm UTC](https://discourse.julialang.org/t/thread-safe-buffer-which-blocks-retrieval-when-empty/107352 "2023-12-09T23:16:50Z")

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Does anyone know of a package which implements a (circular) buffer that blocks when popping from it if it’s empty? To give a bit more context, below is a MWE for a program which has one thread running and continuously f…

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## [ModelingToolkit - how to reset integrator](https://discourse.julialang.org/t/modelingtoolkit-how-to-reset-integrator/107364)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 4\
**Last updated:** [December 9, 2023, 9:17pm UTC](https://discourse.julialang.org/t/modelingtoolkit-how-to-reset-integrator/107364 "2023-12-09T21:17:32Z")

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I have the following code: # Falling mass, attached to non-linear spring without compression stiffness, # initially moving upwards with 4 m/s. using ModelingToolkit, OrdinaryDiffEq, PyPlot, LinearAlgebra G\_EARTH = Flo…

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## [Infeasible warmstart with JuMP & HiGHS](https://discourse.julialang.org/t/infeasible-warmstart-with-jump-highs/106869)

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**Author:** [@ffevotte](https://discourse.julialang.org/u/ffevotte)\
**Replies:** 7\
**Last updated:** [December 9, 2023, 8:47pm UTC](https://discourse.julialang.org/t/infeasible-warmstart-with-jump-highs/106869 "2023-12-09T20:47:20Z")

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I’m a bit at a loss with an issue I have when trying to warmstart HiGHS on my model. EDIT: I originally did not manage to build a minimal reproducer, so I made a relatively messy post (kept below for posterity). But I j…

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## [Optimization with complex requirements](https://discourse.julialang.org/t/optimization-with-complex-requirements/107266)

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**Author:** [@AwesomeQuest](https://discourse.julialang.org/u/AwesomeQuest)\
**Replies:** 3\
**Last updated:** [December 9, 2023, 8:33pm UTC](https://discourse.julialang.org/t/optimization-with-complex-requirements/107266 "2023-12-09T20:33:12Z")

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My optimization problem can be simplified as follows. A vector of coefficients x has an upper an lower bound for each element. μ is a function of the elements of x that itself has an upper and lower bound. And μ has a…

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## [Problem to use Javis](https://discourse.julialang.org/t/problem-to-use-javis/107367)

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**Author:** [@Abdou](https://discourse.julialang.org/u/Abdou)\
**Replies:** 0\
**Last updated:** [December 9, 2023, 8:27pm UTC](https://discourse.julialang.org/t/problem-to-use-javis/107367 "2023-12-09T20:27:56Z")

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after installing the latest version of Javis(0.9) on windows 7 sp1 and trying to use it, the compilation of the package gives a lot of error messages which the first is about accessing a file in my Temp directory for re…

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## [Best way to root a pipeline directory structure inside of a package](https://discourse.julialang.org/t/best-way-to-root-a-pipeline-directory-structure-inside-of-a-package/107275)

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**Author:** [@cdawg](https://discourse.julialang.org/u/cdawg)\
**Replies:** 9\
**Last updated:** [December 9, 2023, 7:44pm UTC](https://discourse.julialang.org/t/best-way-to-root-a-pipeline-directory-structure-inside-of-a-package/107275 "2023-12-09T19:44:15Z")

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I’ve written some bioinformatics analysis scripts in julia. They are fast and impressed everyone! :heart\_eyes: Now I would like to share them with my collaborators. They act inside a pipeline that took many years to deve…

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## [Scopes: accessing a global variable hidden by a local of the same name](https://discourse.julialang.org/t/scopes-accessing-a-global-variable-hidden-by-a-local-of-the-same-name/107253)

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**Author:** [@ryofurue](https://discourse.julialang.org/u/ryofurue)\
**Replies:** 17\
**Last updated:** [December 9, 2023, 7:43pm UTC](https://discourse.julialang.org/t/scopes-accessing-a-global-variable-hidden-by-a-local-of-the-same-name/107253 "2023-12-09T19:43:56Z")

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I’m not exactly “new to Julia” but I thought this would belong here. How do you access a global variable hidden by a local variable of the same name? Reading the documentation (see the bottom of this message), I got th…

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## [Error building SymPy and PyCall when username has a space](https://discourse.julialang.org/t/error-building-sympy-and-pycall-when-username-has-a-space/107214)

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**Author:** [@cjslc008](https://discourse.julialang.org/u/cjslc008)\
**Replies:** 6\
**Last updated:** [December 9, 2023, 7:04pm UTC](https://discourse.julialang.org/t/error-building-sympy-and-pycall-when-username-has-a-space/107214 "2023-12-09T19:04:36Z")

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Hi I’m trying to use SymPy and PyCall,but there is an error of a bad installation to both of them.When I use the the command Pkg.build ,it says that there is an error of precompilation as Miniconda doesn’t support the d…

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## [Creating an package (and eventually app) with Python dependencies](https://discourse.julialang.org/t/creating-an-package-and-eventually-app-with-python-dependencies/107317)

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**Author:** [@sadish-d](https://discourse.julialang.org/u/sadish-d)\
**Replies:** 9\
**Last updated:** [December 9, 2023, 6:37pm UTC](https://discourse.julialang.org/t/creating-an-package-and-eventually-app-with-python-dependencies/107317 "2023-12-09T18:37:21Z")

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I’m working on my first package ever in any language. I want to eventually turn this package into an standalone app (using PackageCompiler.jl). I am running into some trouble. My (local) package MyPackage uses a python …

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## [GTK4 DropDown](https://discourse.julialang.org/t/gtk4-dropdown/107359)

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**Author:** [@SergeantMike67](https://discourse.julialang.org/u/SergeantMike67)\
**Replies:** 1\
**Last updated:** [December 9, 2023, 6:28pm UTC](https://discourse.julialang.org/t/gtk4-dropdown/107359 "2023-12-09T18:28:55Z")

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Keeping it simple about Drop Down widget how do you capture the item into a variable for use in a SQL query? how do you put in a list of new items into a previously created Drop Down? These seem like very basic …

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## [Allow \`CategoricalArray\` when registering a \`DataFrame\` as \`ENUM\` in DuckDB](https://discourse.julialang.org/t/allow-categoricalarray-when-registering-a-dataframe-as-enum-in-duckdb/107365)

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**Author:** [@danielw2904](https://discourse.julialang.org/u/danielw2904)\
**Replies:** 0\
**Last updated:** [December 9, 2023, 5:15pm UTC](https://discourse.julialang.org/t/allow-categoricalarray-when-registering-a-dataframe-as-enum-in-duckdb/107365 "2023-12-09T17:15:40Z")

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Currently CategoricalArrays are not supported in DuckDB but I think it would be a good idea to do so. I have started a discussion on their Github repo. Would it be possible to add this using the new optional dependencies…

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## [Why does Julia support \`::Vector \* ::Matrix\`?](https://discourse.julialang.org/t/why-does-julia-support-vector-matrix/107330)

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**Author:** [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Replies:** 7\
**Last updated:** [December 9, 2023, 3:46pm UTC](https://discourse.julialang.org/t/why-does-julia-support-vector-matrix/107330 "2023-12-09T15:46:41Z")

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For example, julia\> \[1,2\] \* \[2;;\] 2×1 Matrix{Int64}: 2 4 This reshapes the vector as a n x 1 matrix and multiplies it with the 1 x 1 matrix. This seems to go against the general idea of treating Vectors and Matrices …

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## [Difference between '::UInt64' and '::Type(UInt64)'](https://discourse.julialang.org/t/difference-between-uint64-and-type-uint64/107355)

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**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 1\
**Last updated:** [December 9, 2023, 12:02pm UTC](https://discourse.julialang.org/t/difference-between-uint64-and-type-uint64/107355 "2023-12-09T12:02:44Z")

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I saw functions defined as function check\_bitstring\_typeparams(::Val{B}, ::Val{1}, ::Type{UInt64}) where {B} if B \> 64 error("$B bits do not fit into a 64-bit chunk") end end What is the difference betw…

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## [Tullio broadcasting issue](https://discourse.julialang.org/t/tullio-broadcasting-issue/107321)

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**Author:** [@swanchristmas](https://discourse.julialang.org/u/swanchristmas)\
**Replies:** 4\
**Last updated:** [December 9, 2023, 11:46am UTC](https://discourse.julialang.org/t/tullio-broadcasting-issue/107321 "2023-12-09T11:46:28Z")

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@tensor tmp1\[m,s,n,p\] := -λ\[l,m,s\]\*ω\[l,k\]\*λ\[k,n,p\] + λ\[l,m,s\]\*g\[l,n\]\*ones(2)\[p\]) @tullio tmp2\[m,s,n,p\] := -λ\[l,m,s\]\*ω\[l,k\]\*λ\[k,n,p\] + λ\[l,m,s\]\*g\[l,n\] tmp1 turns out to be different from tmp2. It seems that @tullio perfo…

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## [What is the IO interface?](https://discourse.julialang.org/t/what-is-the-io-interface/107350)

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**Author:** [@mkitti](https://discourse.julialang.org/u/mkitti)\
**Replies:** 2\
**Last updated:** [December 9, 2023, 4:29am UTC](https://discourse.julialang.org/t/what-is-the-io-interface/107350 "2023-12-09T04:29:45Z")

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@jameson recently mentioned an IO interface in a review. The lack of documentation on this matter was mentioned several years ago. My best guess at that moment is that the core interface is inferrable from this part of …

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## [UndefVarError: 'N' not defined when solving ODE on GPU](https://discourse.julialang.org/t/undefvarerror-n-not-defined-when-solving-ode-on-gpu/107347)

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**Author:** [@ian](https://discourse.julialang.org/u/ian)\
**Replies:** 3\
**Last updated:** [December 9, 2023, 1:19am UTC](https://discourse.julialang.org/t/undefvarerror-n-not-defined-when-solving-ode-on-gpu/107347 "2023-12-09T01:19:23Z")

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Hi. I’m experimenting with using GPUs to solve large systems of ODEs. As an intial test I am running the following using DifferentialEquations, CUDA, LinearAlgebra function dynamics!(du, u, p, t) mul!(du, p, u) end…

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## [Is 'SVector' a keyword in julia?](https://discourse.julialang.org/t/is-svector-a-keyword-in-julia/107306)

<div class="topic-metadata">

**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 10\
**Last updated:** [December 8, 2023, 11:48pm UTC](https://discourse.julialang.org/t/is-svector-a-keyword-in-julia/107306 "2023-12-08T23:48:31Z")

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In a package, I see a lot of ‘SVector’. It looks like a datatype. But I cannot find it by help. help?\> SVector search: DenseVector SparseVector AbstractVector StridedVector AbstractSparseVector DenseVecOrMat Couldn't f…

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## [Issue adapting NeuralPDE.jl documentation example code to use case](https://discourse.julialang.org/t/issue-adapting-neuralpde-jl-documentation-example-code-to-use-case/107198)

<div class="topic-metadata">

**Author:** [@BenWhip](https://discourse.julialang.org/u/BenWhip)\
**Replies:** 2\
**Last updated:** [December 8, 2023, 11:45pm UTC](https://discourse.julialang.org/t/issue-adapting-neuralpde-jl-documentation-example-code-to-use-case/107198 "2023-12-08T23:45:48Z")

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Hello everyone, I am attempting to adapt the code from \[an example in the NeuralPDE documentation\], but am running into trouble. I am still fairly new at using Julia, so I apologize in advance if the solution is trivial…

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## [Package test (based on shuffle) ok locally and on GitHub CI but failing on PkgEval](https://discourse.julialang.org/t/package-test-based-on-shuffle-ok-locally-and-on-github-ci-but-failing-on-pkgeval/107334)

<div class="topic-metadata">

**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 6\
**Last updated:** [December 8, 2023, 11:35pm UTC](https://discourse.julialang.org/t/package-test-based-on-shuffle-ok-locally-and-on-github-ci-but-failing-on-pkgeval/107334 "2023-12-08T23:35:12Z")

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In my package I have a partition function that randomly partitions a set of arrays into different shares, keeping the order across the various arrays. I test it using on StableRNGs.jl and I have the test working both lo…

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## [Unique (indices) method similar to MATLAB](https://discourse.julialang.org/t/unique-indices-method-similar-to-matlab/34446)

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**Author:** [@chakravala](https://discourse.julialang.org/u/chakravala)\
**Replies:** 7\
**Last updated:** [December 8, 2023, 10:43pm UTC](https://discourse.julialang.org/t/unique-indices-method-similar-to-matlab/34446 "2023-12-08T22:43:15Z")

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Is there a method in Julia similar to MATLAB’s unique method? In Julia there is unique, but it does not have the same functionality. Specifically, I would like to get the list of indices of unique elements. julia\> uniqu…

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