# Latest

**URL:** https://discourse.julialang.org/latest.md?page=287

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

**Page:** 288

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## [RFC: macro for checking that a struct is concretely typed](https://discourse.julialang.org/t/rfc-macro-for-checking-that-a-struct-is-concretely-typed/122017)

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**Author:** [@gdalle](https://discourse.julialang.org/u/gdalle)\
**Replies:** 10\
**Last updated:** [October 31, 2024, 6:20am UTC](https://discourse.julialang.org/t/rfc-macro-for-checking-that-a-struct-is-concretely-typed/122017 "2024-10-31T06:20:25Z")

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This week I gave a tutorial on performance in Julia and helped a few beginners optimize their code. One of the most frequent mistakes was structs with abstractly-typed fields. As a pedagogical tool, @serenity4 and I wro…

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## [Curl\_multi\_assign and segmentation fault when installing package](https://discourse.julialang.org/t/curl-multi-assign-and-segmentation-fault-when-installing-package/120901)

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**Author:** [@arnerob](https://discourse.julialang.org/u/arnerob)\
**Replies:** 5\
**Last updated:** [October 4, 2024, 5:31pm UTC](https://discourse.julialang.org/t/curl-multi-assign-and-segmentation-fault-when-installing-package/120901 "2024-10-04T17:31:04Z")

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I recently switched to Apple M2 and I tried to install FFTW.jl. I did the following in a fresh REPL: julia\> using Pkg julia\> Pkg.add("FFTW") Resolving package versions... Updating \`~/.julia/environments/v1.10/Pr…

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## [Large scale model using Gurobi causes machine crushed](https://discourse.julialang.org/t/large-scale-model-using-gurobi-causes-machine-crushed/121988)

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**Author:** [@Betristor](https://discourse.julialang.org/u/Betristor)\
**Replies:** 11\
**Last updated:** [October 31, 2024, 2:40am UTC](https://discourse.julialang.org/t/large-scale-model-using-gurobi-causes-machine-crushed/121988 "2024-10-31T02:40:50Z")

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For the record, I still have not found the reason why my server crushed solving some large models using JuMP+Gurobi. But I have experienced like dozens of times. Here is the situation. Each time I constructed a JuMP mod…

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## [Cannot create 2D Cartesian points with specified units](https://discourse.julialang.org/t/cannot-create-2d-cartesian-points-with-specified-units/122020)

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**Author:** [@prittjam](https://discourse.julialang.org/u/prittjam)\
**Replies:** 12\
**Last updated:** [October 30, 2024, 10:45pm UTC](https://discourse.julialang.org/t/cannot-create-2d-cartesian-points-with-specified-units/122020 "2024-10-30T22:45:40Z")

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using CoordRefSystems, Unitful rand(Cartesian2D{NoDatum, typeof(1.0u"m")}) does not work.

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## [Emacs julia-ts-mode](https://discourse.julialang.org/t/emacs-julia-ts-mode/122018)

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**Author:** [@warnerwarner](https://discourse.julialang.org/u/warnerwarner)\
**Replies:** 2\
**Last updated:** [October 30, 2024, 10:02pm UTC](https://discourse.julialang.org/t/emacs-julia-ts-mode/122018 "2024-10-30T22:02:17Z")

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I’ve tried to set up julia-ts-mode using treesitter-auto in emacs, but whenever I open a julia .jl file there is no treesitting changes e.g. no syntax highlighting etc. I’m using it conjunection wtih julia-snail, but fro…

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## [Bizarre behaviour of WGLMakie](https://discourse.julialang.org/t/bizarre-behaviour-of-wglmakie/122021)

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**Author:** [@adhalanay](https://discourse.julialang.org/u/adhalanay)\
**Replies:** 0\
**Last updated:** [October 30, 2024, 9:43pm UTC](https://discourse.julialang.org/t/bizarre-behaviour-of-wglmakie/122021 "2024-10-30T21:43:52Z")

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I am trying to create an interactive plot to be shown in jupyterlab. The content of the cell is using WGLMakie using Bonito x0=0.01 fig=Figure() ax=Axis(fig\[1,1\]) slr=WGLMakie.SliderGrid(fig\[2, 1\], (label="r",rang…

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## [Very Slow \`DBInterface.execute\` on large duckdb relative to R](https://discourse.julialang.org/t/very-slow-dbinterface-execute-on-large-duckdb-relative-to-r/121984)

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**Author:** [@floswald](https://discourse.julialang.org/u/floswald)\
**Replies:** 4\
**Last updated:** [October 30, 2024, 9:11pm UTC](https://discourse.julialang.org/t/very-slow-dbinterface-execute-on-large-duckdb-relative-to-r/121984 "2024-10-30T21:11:59Z")

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Hi all, I’ve made a clone of @grantmcdermott 's nice workshop on duckdb and polars - adding a chapter on julia and duckdb. He had pointed out some very slow julia timings in his slides, and actually created an issue on …

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## [Reformulating Logarithmic Objective Function for Gurobi in Julia with JuMP](https://discourse.julialang.org/t/reformulating-logarithmic-objective-function-for-gurobi-in-julia-with-jump/121961)

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**Author:** [@Beyza\_Aydin](https://discourse.julialang.org/u/Beyza_Aydin)\
**Replies:** 3\
**Last updated:** [October 30, 2024, 8:25pm UTC](https://discourse.julialang.org/t/reformulating-logarithmic-objective-function-for-gurobi-in-julia-with-jump/121961 "2024-10-30T20:25:20Z")

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Hi, I’m working on an optimization problem in Julia where I need to maximize a logarithmic objective function (maximize sum of logs ): @objective(model, Max, sum(alp\[i\] \* log( p\[i\]) for i in 1:n)) where alp is vector…

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## [Odd warning and issues with optimization only when inside Optimization.jl. Zygote.hessian works fine](https://discourse.julialang.org/t/odd-warning-and-issues-with-optimization-only-when-inside-optimization-jl-zygote-hessian-works-fine/121967)

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**Author:** [@Hareruya](https://discourse.julialang.org/u/Hareruya)\
**Replies:** 8\
**Last updated:** [October 30, 2024, 7:39pm UTC](https://discourse.julialang.org/t/odd-warning-and-issues-with-optimization-only-when-inside-optimization-jl-zygote-hessian-works-fine/121967 "2024-10-30T19:39:55Z")

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Greetings, everyone. Apologies if the query is too basic, as it does not impede optimization in one case. I have graduated from my PhD program and have gotten a job at a company that offers me freedom in what programmin…

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## [BoundsError: attempt to access 55-element Vector{Float64} at index \[3-element BitVector\] OR UndefVarError: \`vertex\_counter\` not defined](https://discourse.julialang.org/t/boundserror-attempt-to-access-55-element-vector-float64-at-index-3-element-bitvector-or-undefvarerror-vertex-counter-not-defined/121955)

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**Author:** [@tfranks](https://discourse.julialang.org/u/tfranks)\
**Replies:** 7\
**Last updated:** [October 30, 2024, 6:37pm UTC](https://discourse.julialang.org/t/boundserror-attempt-to-access-55-element-vector-float64-at-index-3-element-bitvector-or-undefvarerror-vertex-counter-not-defined/121955 "2024-10-30T18:37:07Z")

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Hello, I’ve created bank and depositor agents and would now like to render as a graph with banks as the nodes and the depositors forming the edges that change at every time step. A snippet of the data frame is inserted…

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## [Webpage with reactive plot animation](https://discourse.julialang.org/t/webpage-with-reactive-plot-animation/121570)

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**Author:** [@cstjean](https://discourse.julialang.org/u/cstjean)\
**Replies:** 3\
**Last updated:** [October 30, 2024, 6:02pm UTC](https://discourse.julialang.org/t/webpage-with-reactive-plot-animation/121570 "2024-10-30T18:02:44Z")

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I’d like to have a webpage with a plot which gets updated automatically every second, and which depends on some user input. Schematically, something like: julia\> xs = \[0\]; vx = ReactiveSlider(initial\_value=1) whi…

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## [Appending new formatted lines in a file using writedlm()?](https://discourse.julialang.org/t/appending-new-formatted-lines-in-a-file-using-writedlm/121915)

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**Author:** [@ValeFed](https://discourse.julialang.org/u/ValeFed)\
**Replies:** 1\
**Last updated:** [October 30, 2024, 5:55pm UTC](https://discourse.julialang.org/t/appending-new-formatted-lines-in-a-file-using-writedlm/121915 "2024-10-30T17:55:59Z")

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Hi there. My ingredients are some coordinates and a function N that returns a 4-element Vector. I need to create a txt file that has as colums x,y, N\[1\], N\[2\], N\[3\] and N\[4\]. Two other important info are that N is creat…

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## [Reading and writing a global variable](https://discourse.julialang.org/t/reading-and-writing-a-global-variable/121996)

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**Author:** [@Matthijs\_1971](https://discourse.julialang.org/u/Matthijs_1971)\
**Replies:** 2\
**Last updated:** [October 30, 2024, 4:50pm UTC](https://discourse.julialang.org/t/reading-and-writing-a-global-variable/121996 "2024-10-30T16:50:24Z")

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Please consider the following code: module MyModule global MY\_GLOBAL = 42 function test()::Nothing println("MY\_GLOBAL ", MY\_GLOBAL) # MY\_GLOBAL = 3 return nothing end en…

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## [Create a boolean mask between arrays of different size](https://discourse.julialang.org/t/create-a-boolean-mask-between-arrays-of-different-size/121986)

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**Author:** [@Ju\_ska](https://discourse.julialang.org/u/Ju_ska)\
**Replies:** 10\
**Last updated:** [October 30, 2024, 4:43pm UTC](https://discourse.julialang.org/t/create-a-boolean-mask-between-arrays-of-different-size/121986 "2024-10-30T16:43:34Z")

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Hi, I would like to do the same thing as in python: import numpy as np a=\[1,2,3,4,5,6,7\] b=\[2,4,6\] mask=np.isin(a,b) giving \>\>\> mask array(\[False, True, False, True, False, True, False\]) In julia I can: mask = in…

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## [Do you put return type in function definitions?](https://discourse.julialang.org/t/do-you-put-return-type-in-function-definitions/32120)

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**Author:** [@tk3369](https://discourse.julialang.org/u/tk3369)\
**Replies:** 14\
**Last updated:** [May 12, 2022, 7:15pm UTC](https://discourse.julialang.org/t/do-you-put-return-type-in-function-definitions/32120 "2022-05-12T19:15:43Z")

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Do you have any opinion about annotating function definitions with return types? Like it or not and why? Here’s a dummy example: add(x, y)::Int = x + y It gives additional type checking: julia\> add(1,2) 3 julia\> ad…

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## [Running CUDA.jl test results in my PC with Ubuntu 22.04 to freeze and become unresponsive\`](https://discourse.julialang.org/t/running-cuda-jl-test-results-in-my-pc-with-ubuntu-22-04-to-freeze-and-become-unresponsive/118434)

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**Author:** [@Mend-Amar\_Badral](https://discourse.julialang.org/u/Mend-Amar_Badral)\
**Replies:** 12\
**Last updated:** [October 30, 2024, 4:03pm UTC](https://discourse.julialang.org/t/running-cuda-jl-test-results-in-my-pc-with-ubuntu-22-04-to-freeze-and-become-unresponsive/118434 "2024-10-30T16:03:00Z")

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I have a PC that runs Ubuntu that has nvidia gpu(3080ti). I’ve installed CUDA.jl recently, and I believe pc has met all the requirements. It has Nvidia drivers installed. But when I enter pkg\> test CUDA There was an er…

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## [Pointer to stackframe in Julia, VLA/alloca-like; with e.g. StaticString.jl](https://discourse.julialang.org/t/pointer-to-stackframe-in-julia-vla-alloca-like-with-e-g-staticstring-jl/121992)

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**Author:** [@Palli](https://discourse.julialang.org/u/Palli)\
**Replies:** 5\
**Last updated:** [October 30, 2024, 2:57pm UTC](https://discourse.julialang.org/t/pointer-to-stackframe-in-julia-vla-alloca-like-with-e-g-staticstring-jl/121992 "2024-10-30T14:57:05Z")

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I’m optimizing allocations away, for printing general strings (one of the last one is because of Libc.malloc(200), effectively in Julia, and it could be on the stack if Julia had such capability like in C). It IS danger…

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## [The runtime type and the variable type](https://discourse.julialang.org/t/the-runtime-type-and-the-variable-type/121868)

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**Author:** [@world-peace](https://discourse.julialang.org/u/world-peace)\
**Replies:** 17\
**Last updated:** [October 30, 2024, 1:59pm UTC](https://discourse.julialang.org/t/the-runtime-type-and-the-variable-type/121868 "2024-10-30T13:59:14Z")

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Here’s a short experiment which demonstrates that the runtime type is an independent piece of information from the type of a variable. julia\> x::Any="hello world" "hello world" julia\> typeof(x) String julia\> x=1 1 ju…

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## [Makie Observable Bug](https://discourse.julialang.org/t/makie-observable-bug/121724)

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**Author:** [@Allan\_Baker](https://discourse.julialang.org/u/Allan_Baker)\
**Replies:** 4\
**Last updated:** [October 29, 2024, 9:27pm UTC](https://discourse.julialang.org/t/makie-observable-bug/121724 "2024-10-29T21:27:07Z")

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I can’t figure out how to squash this. I’ve never had this problem before when using Observables and Makie. What’s the secret. For a surface plot, when I update the x-vector and change its size, and update the Z vecto…

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## [Why does a vector with 10 times more elements takes 2x-5x less time to pre-allocate?](https://discourse.julialang.org/t/why-does-a-vector-with-10-times-more-elements-takes-2x-5x-less-time-to-pre-allocate/121828)

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**Author:** [@Olegg](https://discourse.julialang.org/u/Olegg)\
**Replies:** 14\
**Last updated:** [October 30, 2024, 1:13pm UTC](https://discourse.julialang.org/t/why-does-a-vector-with-10-times-more-elements-takes-2x-5x-less-time-to-pre-allocate/121828 "2024-10-30T13:13:11Z")

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I’m benchmarking pre-allocation of vectors: display(@benchmark Vector{Int}(undef, 1000) ) display(@benchmark Vector{Int}(undef, 10000) ) display(@benchmark Vector{Int}(undef, 1000) ) display(@benchmark Vector{Int}(u…

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## [The One Billion Row Challenge](https://discourse.julialang.org/t/the-one-billion-row-challenge/109534)

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**Author:** [@3j5a](https://discourse.julialang.org/u/3j5a)\
**Replies:** 29\
**Last updated:** [October 30, 2024, 12:58pm UTC](https://discourse.julialang.org/t/the-one-billion-row-challenge/109534 "2024-10-30T12:58:21Z")

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There’s been a challenge in Java community that generated a considerable amount of interest I’d say: The One Billion Row Challenge “A fun exploration of how quickly 1B rows from a text file can be aggregated with Java”. …

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## [Performing max-min optimization with optimization.jl](https://discourse.julialang.org/t/performing-max-min-optimization-with-optimization-jl/121991)

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**Author:** [@KianH](https://discourse.julialang.org/u/KianH)\
**Replies:** 0\
**Last updated:** [October 30, 2024, 12:36pm UTC](https://discourse.julialang.org/t/performing-max-min-optimization-with-optimization-jl/121991 "2024-10-30T12:36:01Z")

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Hello, I was wondering if it is possible to solve minimax optimization problems using Optimization.jl for neural networks? I am currently performing the optimization using Optimization.solve(...). I am specifically inte…

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## [What are "Verbosity logging macros?"](https://discourse.julialang.org/t/what-are-verbosity-logging-macros/121791)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 15\
**Last updated:** [October 30, 2024, 12:32pm UTC](https://discourse.julialang.org/t/what-are-verbosity-logging-macros/121791 "2024-10-30T12:32:56Z")

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I am getting this warning: ┌ KiteUtils │ ┌ Warning: Verbosity logging macros are deprecated as they are not compatible with juliac-compiled programs │ │ caller = ip:0x0 │ └ @ Core :-1 └ But what are “Verbosity l…

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## [GLMakie with github CI](https://discourse.julialang.org/t/glmakie-with-github-ci/106440)

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**Author:** [@rwillcox](https://discourse.julialang.org/u/rwillcox)\
**Replies:** 4\
**Last updated:** [October 30, 2024, 10:42am UTC](https://discourse.julialang.org/t/glmakie-with-github-ci/106440 "2024-10-30T10:42:15Z")

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Hi new Julia user here, hoping this is the right community to help answer my question. I’m having issues with GLMakie and my github CI yaml. I’m aware there’s a bit of discussion about this elsewhere online, but haven’t…

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## [MKLPardisoSolver() problem](https://discourse.julialang.org/t/mklpardisosolver-problem/121882)

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**Author:** [@NTH](https://discourse.julialang.org/u/NTH)\
**Replies:** 2\
**Last updated:** [October 30, 2024, 10:13am UTC](https://discourse.julialang.org/t/mklpardisosolver-problem/121882 "2024-10-30T10:13:24Z")

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Hello everyone, I’m very new to Julia and right now I’m testing the function MKLPardisoSolver() but I always received the error: ERROR: LoadError: MKL is not available Stacktrace: \[1\] error(s::String) @ Base ./error.…

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## [How to integrate parse with split?](https://discourse.julialang.org/t/how-to-integrate-parse-with-split/121819)

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**Author:** [@hack3rcon](https://discourse.julialang.org/u/hack3rcon)\
**Replies:** 3\
**Last updated:** [October 30, 2024, 9:00am UTC](https://discourse.julialang.org/t/how-to-integrate-parse-with-split/121819 "2024-10-30T09:00:52Z")

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Hello, How can I correct the command a, b, c = parse(Int,split(readline()))? I want to receive three inputs and simultaneously convert it to an integer and assign it to each of the variables. Thank you.

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## [How to convert a cup array to a gpu array](https://discourse.julialang.org/t/how-to-convert-a-cup-array-to-a-gpu-array/121983)

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**Author:** [@Yaozhong\_Liu](https://discourse.julialang.org/u/Yaozhong_Liu)\
**Replies:** 3\
**Last updated:** [October 30, 2024, 8:10am UTC](https://discourse.julialang.org/t/how-to-convert-a-cup-array-to-a-gpu-array/121983 "2024-10-30T08:10:20Z")

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Hi. I know how to create a gpu array, but has no clue how to convert an initialized array to a gpu array in a julia file rather than the julia prompt. I tried code like this: # In a julia file A = \[1.0, 2.0, 3.0\] |\> g…

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## [Compiled binary hangs on Windows when receiving SIGABRT](https://discourse.julialang.org/t/compiled-binary-hangs-on-windows-when-receiving-sigabrt/121982)

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**Author:** [@jsjie](https://discourse.julialang.org/u/jsjie)\
**Replies:** 0\
**Last updated:** [October 30, 2024, 7:34am UTC](https://discourse.julialang.org/t/compiled-binary-hangs-on-windows-when-receiving-sigabrt/121982 "2024-10-30T07:34:09Z")

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The binary is compiled with julia 1.9.4. The following two problems both lead to hanging: Cannot protect page @0000000000000000 of size 1048576 to 0x4 (err 0x1e7) \[12024\] signal (22): SIGABRT in expression starting at …

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## [Confusion in terminology dt & timing in agents.jl continuous time/EBM model](https://discourse.julialang.org/t/confusion-in-terminology-dt-timing-in-agents-jl-continuous-time-ebm-model/121748)

<div class="topic-metadata">

**Author:** [@Sahil\_Khan](https://discourse.julialang.org/u/Sahil_Khan)\
**Replies:** 3\
**Last updated:** [October 30, 2024, 7:11am UTC](https://discourse.julialang.org/t/confusion-in-terminology-dt-timing-in-agents-jl-continuous-time-ebm-model/121748 "2024-10-30T07:11:34Z")

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Hello everyone, Im working with EBM continuous time model. Im little confused between dt given in model initiation function and timing term while defining events for model. It will be really helpful if someone can desc…

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## [How to perform practical identifiability in Julia?](https://discourse.julialang.org/t/how-to-perform-practical-identifiability-in-julia/121671)

<div class="topic-metadata">

**Author:** [@Nick1](https://discourse.julialang.org/u/Nick1)\
**Replies:** 3\
**Last updated:** [October 30, 2024, 6:59am UTC](https://discourse.julialang.org/t/how-to-perform-practical-identifiability-in-julia/121671 "2024-10-30T06:59:20Z")

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Is there a way to perform practical identifiability in Julia? I have a systems biology problem with limited data and want to determine which parameters are practically identifiable.

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