# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1255

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

**Page:** 1256

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## [Reading string including Greek letters from SQL server](https://discourse.julialang.org/t/reading-string-including-greek-letters-from-sql-server/68682)

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**Author:** [@mobar](https://discourse.julialang.org/u/mobar)\
**Replies:** 2\
**Last updated:** [September 26, 2021, 7:40pm UTC](https://discourse.julialang.org/t/reading-string-including-greek-letters-from-sql-server/68682 "2021-09-26T19:40:57Z")

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I need to store serialized JSON strings of types that include Greek letters (such as λ) on an sql server table. Storing works just fine (field defined as nvarchar(max) data type) and sql prefixed with N) - but I’m havin…

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## [A couple of questions about arrays and "findall" function](https://discourse.julialang.org/t/a-couple-of-questions-about-arrays-and-findall-function/68785)

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**Author:** [@Jesus-117](https://discourse.julialang.org/u/Jesus-117)\
**Replies:** 3\
**Last updated:** [September 26, 2021, 7:23pm UTC](https://discourse.julialang.org/t/a-couple-of-questions-about-arrays-and-findall-function/68785 "2021-09-26T19:23:40Z")

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Hello there !! I am new to programming in general and I have a couple of questions about how to use strings, if I have an example text and I would like to count the spaces in the text like this: ExampleText= "a b c d e …

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## [Manipulating Parameters of Parametrized Types](https://discourse.julialang.org/t/manipulating-parameters-of-parametrized-types/68763)

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**Author:** [@Ian\_Slagle](https://discourse.julialang.org/u/Ian_Slagle)\
**Replies:** 6\
**Last updated:** [September 26, 2021, 7:04pm UTC](https://discourse.julialang.org/t/manipulating-parameters-of-parametrized-types/68763 "2021-09-26T19:04:26Z")

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I have a struct which is composed of N components and N - 1 weights (because they add up to 1 and I don’t need the additional degree of freedom). My attempt is below struct WeightedComponents{N} components::NTuple{N…

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## [Linnea: automatic generation of efficient linear algebra programs](https://discourse.julialang.org/t/linnea-automatic-generation-of-efficient-linear-algebra-programs/66288)

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**Author:** [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Replies:** 13\
**Last updated:** [September 26, 2021, 5:39pm UTC](https://discourse.julialang.org/t/linnea-automatic-generation-of-efficient-linear-algebra-programs/66288 "2021-09-26T17:39:21Z")

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Came across this interesting article about Linnea and would like to share it. The authors claim that the code Linnea generates almost always outperforms the recommended implementations in Matlab, Julia, Eigen and Armadi…

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## [Symbolics and substitution using broadcasting](https://discourse.julialang.org/t/symbolics-and-substitution-using-broadcasting/68705)

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**Author:** [@Gravlax](https://discourse.julialang.org/u/Gravlax)\
**Replies:** 5\
**Last updated:** [September 26, 2021, 4:50pm UTC](https://discourse.julialang.org/t/symbolics-and-substitution-using-broadcasting/68705 "2021-09-26T16:50:50Z")

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Hello everyone, I’m trying to substitute some variables by some strings in a matrix using broadcasting. The aim is to make the visually simplify the expression such that stuff like eta(Exx,Eyy,Exy) simply reads as eta …

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## [Jupyter / IJulia: Cell containing code suddenly turned blank](https://discourse.julialang.org/t/jupyter-ijulia-cell-containing-code-suddenly-turned-blank/53354)

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**Author:** [@Michael\_Barmann](https://discourse.julialang.org/u/Michael_Barmann)\
**Replies:** 11\
**Last updated:** [September 26, 2021, 1:44pm UTC](https://discourse.julialang.org/t/jupyter-ijulia-cell-containing-code-suddenly-turned-blank/53354 "2021-09-26T13:44:38Z")

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I’m working in a Jupyter Notebook and while in the midst of typing code, the cell I was typing in suddenly turned blank. When I try clicking on the blank cell, nothing happens. I can run the cell by clicking the little b…

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## [Julia could have a Tau constant](https://discourse.julialang.org/t/julia-could-have-a-tau-constant/68181)

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**Author:** [@Lucas\_Queiroz](https://discourse.julialang.org/u/Lucas_Queiroz)\
**Replies:** 33\
**Last updated:** [September 26, 2021, 1:38pm UTC](https://discourse.julialang.org/t/julia-could-have-a-tau-constant/68181 "2021-09-26T13:38:54Z")

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Python is already into the movement. Let’s get into the tau revolution? const taunumber = 6.283

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## [How mature is GalacticOptim for use NLopt algorithms](https://discourse.julialang.org/t/how-mature-is-galacticoptim-for-use-nlopt-algorithms/68764)

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**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 1\
**Last updated:** [September 26, 2021, 12:11pm UTC](https://discourse.julialang.org/t/how-mature-is-galacticoptim-for-use-nlopt-algorithms/68764 "2021-09-26T12:11:30Z")

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GalacticOptim has very convenient features like automatically constructing gradients, etc. but I am worried about its maturity given the thin documentation. Am I better off just using the NLopt.jl API directly?

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## [Compressed Sensing using StructuredOptimization.jl](https://discourse.julialang.org/t/compressed-sensing-using-structuredoptimization-jl/35098)

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**Author:** [@lstagner](https://discourse.julialang.org/u/lstagner)\
**Replies:** 12\
**Last updated:** [September 26, 2021, 11:35am UTC](https://discourse.julialang.org/t/compressed-sensing-using-structuredoptimization-jl/35098 "2021-09-26T11:35:59Z")

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Here is something cool I did: gist using LinearAlgebra using Random using FFTW using PyPlot using StructuredOptimization N = 256 P = 5 K = 32 # Pick out P random frequencies freq = randperm(Int(N/2)).-1 freq = freq\[1:…

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## [Rs Dmnorm equivalent in Julia](https://discourse.julialang.org/t/rs-dmnorm-equivalent-in-julia/68773)

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**Author:** [@djholiver](https://discourse.julialang.org/u/djholiver)\
**Replies:** 2\
**Last updated:** [September 26, 2021, 11:08am UTC](https://discourse.julialang.org/t/rs-dmnorm-equivalent-in-julia/68773 "2021-09-26T11:08:08Z")

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Hi, I am very new to statistical computing but have a need to convert an R script to Julia to mitigate high memory usage and performance challenges. I have been able to clean up quite a bit so far but the below is a sti…

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## [Ok to use Discourse for package-specific tech support?](https://discourse.julialang.org/t/ok-to-use-discourse-for-package-specific-tech-support/65379)

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**Author:** [@miles](https://discourse.julialang.org/u/miles)\
**Replies:** 13\
**Last updated:** [September 26, 2021, 10:41am UTC](https://discourse.julialang.org/t/ok-to-use-discourse-for-package-specific-tech-support/65379 "2021-09-26T10:41:12Z")

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I am one of the developers of the Julia package ITensors.jl GitHub - ITensor/ITensors.jl: A Julia library for efficient tensor computations and tensor network calculations. Currently we run our own support forum (link he…

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## [ImageEdgeDetection: The basic usage example will not compile](https://discourse.julialang.org/t/imageedgedetection-the-basic-usage-example-will-not-compile/68628)

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**Author:** [@Ondo](https://discourse.julialang.org/u/Ondo)\
**Replies:** 2\
**Last updated:** [September 26, 2021, 9:18am UTC](https://discourse.julialang.org/t/imageedgedetection-the-basic-usage-example-will-not-compile/68628 "2021-09-26T09:18:53Z")

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I am completely new to Julia. I want to use some image manipulation functions including those in the ImageEdgeDetection package but already the basic use example provided on the ImageEdgeDetection page will not run. In …

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## [Problem with \`println()\` and \`display()\`, \`display()\` can't display line breaks](https://discourse.julialang.org/t/problem-with-println-and-display-display-cant-display-line-breaks/68762)

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**Author:** [@Torkel](https://discourse.julialang.org/u/Torkel)\
**Replies:** 2\
**Last updated:** [September 26, 2021, 8:57am UTC](https://discourse.julialang.org/t/problem-with-println-and-display-display-cant-display-line-breaks/68762 "2021-09-26T08:57:51Z")

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I have a script that analyses some parameters and prints the result (in a Julia notebook). This includes both text messages and plots. I have problem finding a print format which preserved the order things are printed (l…

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## [How to call arguments from outside of the scope](https://discourse.julialang.org/t/how-to-call-arguments-from-outside-of-the-scope/68752)

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**Author:** [@Jakub\_Mitura](https://discourse.julialang.org/u/Jakub_Mitura)\
**Replies:** 4\
**Last updated:** [September 26, 2021, 8:55am UTC](https://discourse.julialang.org/t/how-to-call-arguments-from-outside-of-the-scope/68752 "2021-09-26T08:55:35Z")

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Hello is it possible to invoke a function to use variable from caller function scope using macros ? I think about sth like function innerFunction() println(a\*4) end function outerContext() a = 4 @useOutArgs innerF…

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## [Not able to load PostgreSQL into LibPQ.jl](https://discourse.julialang.org/t/not-able-to-load-postgresql-into-libpq-jl/68767)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 20\
**Last updated:** [September 26, 2021, 3:45am UTC](https://discourse.julialang.org/t/not-able-to-load-postgresql-into-libpq-jl/68767 "2021-09-26T03:45:21Z")

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I have installed postgressql, and am trying to use the LibPQ.jl . But, when I try to connect conn = LibPQ.Connection("dbname=postgres user=BrettKnoss) I’m told that. conn= could not connect to server: No such file or…

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## [Optional parameter causes type instability](https://discourse.julialang.org/t/optional-parameter-causes-type-instability/68768)

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**Author:** [@Joris\_Pinkse](https://discourse.julialang.org/u/Joris_Pinkse)\
**Replies:** 1\
**Last updated:** [September 26, 2021, 3:19am UTC](https://discourse.julialang.org/t/optional-parameter-causes-type-instability/68768 "2021-09-26T03:19:50Z")

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Using @code\_warntype, function f(x::Float64, T=Float64 ) T(x) end passes with flying colors, but function f(x::Float64; T=Float64) T(x) end causes mayhem. Why?

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## [Julia extension and VScode server](https://discourse.julialang.org/t/julia-extension-and-vscode-server/68759)

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**Author:** [@gianmariomanca](https://discourse.julialang.org/u/gianmariomanca)\
**Replies:** 3\
**Last updated:** [September 26, 2021, 12:28am UTC](https://discourse.julialang.org/t/julia-extension-and-vscode-server/68759 "2021-09-26T00:28:58Z")

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Is the Julia extension tested against VScode server https://github.com/cdr/code-server? The plot gallery didn’t seem to work last time I checked. Related: in general I know that a local VScode can connect via SSH to a …

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## [Notebook on particle simulations](https://discourse.julialang.org/t/notebook-on-particle-simulations/68496)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 27\
**Last updated:** [September 25, 2021, 8:37pm UTC](https://discourse.julialang.org/t/notebook-on-particle-simulations/68496 "2021-09-25T20:37:37Z")

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I have written a notebook on particle simulations using Julia, to be presented at the FortranCon this week: https://m3g.github.io/2021\_FortranCon/ (https://github.com/m3g/2021\_FortranCon) It may be interesting for stu…

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## [Question on Calling Julia functions from C++ with CxxWrap (and Eventually Interfacing with Julia from MATLAB)](https://discourse.julialang.org/t/question-on-calling-julia-functions-from-c-with-cxxwrap-and-eventually-interfacing-with-julia-from-matlab/68378)

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**Author:** [@GrantHecht](https://discourse.julialang.org/u/GrantHecht)\
**Replies:** 2\
**Last updated:** [September 25, 2021, 8:08pm UTC](https://discourse.julialang.org/t/question-on-calling-julia-functions-from-c-with-cxxwrap-and-eventually-interfacing-with-julia-from-matlab/68378 "2021-09-25T20:08:28Z")

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Hello everyone, I have a relatively unique use case for Julia and CxxWrap.jl. To provide some background, my current research involves employing heuristic optimization algorithms to assist in solving spacecraft trajecto…

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## [\[ANN\] Announcing GeometricMultigrid.jl](https://discourse.julialang.org/t/ann-announcing-geometricmultigrid-jl/68754)

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**Author:** [@weymouth](https://discourse.julialang.org/u/weymouth)\
**Replies:** 3\
**Last updated:** [September 25, 2021, 7:35pm UTC](https://discourse.julialang.org/t/ann-announcing-geometricmultigrid-jl/68754 "2021-09-25T19:35:43Z")

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Just a heads-up announcing GeometricMultigrid.jl is now registered, for anyone who is interested. Benchmark example for mg! solver demonstrating NlogN solution time scaling with the length of the solution vector. Th…

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## [How to align x axis in GR](https://discourse.julialang.org/t/how-to-align-x-axis-in-gr/68626)

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**Author:** [@ohmsweetohm1](https://discourse.julialang.org/u/ohmsweetohm1)\
**Replies:** 2\
**Last updated:** [September 25, 2021, 6:11pm UTC](https://discourse.julialang.org/t/how-to-align-x-axis-in-gr/68626 "2021-09-25T18:11:55Z")

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How to align the axis? p1 = Plots.plot(rand(10), label="A very loooooooooooooooong label") p2 = Plots.plot(rand(10), label="A short label") Plots.plot(p1, p2, layout=(2,1), legend=:outerright)

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## [Solving chemical systems of equations with both equilibrium and kinetic species](https://discourse.julialang.org/t/solving-chemical-systems-of-equations-with-both-equilibrium-and-kinetic-species/68755)

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**Author:** [@gagnonaa10](https://discourse.julialang.org/u/gagnonaa10)\
**Replies:** 1\
**Last updated:** [September 25, 2021, 5:52pm UTC](https://discourse.julialang.org/t/solving-chemical-systems-of-equations-with-both-equilibrium-and-kinetic-species/68755 "2021-09-25T17:52:41Z")

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This is building on a different discourse post I made previously: https://discourse.julialang.org/t/constraints-in-catalyst-jl-for-weak-acids-and-ph-equilibrium/68037/2 And on Github: https://github.com/SciML/Catalyst…

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## [How do I check if a variable is an array of numbers](https://discourse.julialang.org/t/how-do-i-check-if-a-variable-is-an-array-of-numbers/68734)

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**Author:** [@StevenSiew](https://discourse.julialang.org/u/StevenSiew)\
**Replies:** 7\
**Last updated:** [September 25, 2021, 5:31pm UTC](https://discourse.julialang.org/t/how-do-i-check-if-a-variable-is-an-array-of-numbers/68734 "2021-09-25T17:31:34Z")

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How do I check if a variable x is a subtype of an array of numbers x = \[1.1, 1.2, 1.3\] julia\> typeof(x) == Array{Float64, 1} true julia\> typeof(x) == Array{Number, 1} false julia\> typeof(x) \<: Array{Number, 1} false…

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## [Using Jetson Nano as replacement for RPi (3D printing)](https://discourse.julialang.org/t/using-jetson-nano-as-replacement-for-rpi-3d-printing/68739)

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**Author:** [@skypuppy](https://discourse.julialang.org/u/skypuppy)\
**Replies:** 1\
**Last updated:** [September 25, 2021, 2:55pm UTC](https://discourse.julialang.org/t/using-jetson-nano-as-replacement-for-rpi-3d-printing/68739 "2021-09-25T14:55:20Z")

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I’d like to use a Jetson Nano as replacement for multiple RPi’s to control several 3D printers. Octoprint is my preferred tool at the start. Octoprint is written in Python so my first labor of love is to translate it i…

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## [How to use btn\_\_toggle in Stipple](https://discourse.julialang.org/t/how-to-use-btn-toggle-in-stipple/56501)

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**Author:** [@yakir12](https://discourse.julialang.org/u/yakir12)\
**Replies:** 6\
**Last updated:** [March 4, 2021, 11:46pm UTC](https://discourse.julialang.org/t/how-to-use-btn-toggle-in-stipple/56501 "2021-03-04T23:46:20Z")

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Hi and thank you @hhaensel :smiley: How can I use btn\_\_toggle in Stipple? I think my struggle is the options property. I can’t get it to work no matter what syntax I use (copy-paste the JS from the example, vector of na…

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## [How to pass optimizer options to GalacticOptim?](https://discourse.julialang.org/t/how-to-pass-optimizer-options-to-galacticoptim/68742)

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**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 1\
**Last updated:** [September 25, 2021, 10:35am UTC](https://discourse.julialang.org/t/how-to-pass-optimizer-options-to-galacticoptim/68742 "2021-09-25T10:35:45Z")

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I’m trying to play with GalacticOptim. How can I pass options to the optimizer? In plain Optim, I can pass options like store\_trace with Optim.Options(store\_trace=true). How can I pass those options in the example below? …

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## [Anyone experimented with Jetson Nano's?](https://discourse.julialang.org/t/anyone-experimented-with-jetson-nanos/68738)

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**Author:** [@skypuppy](https://discourse.julialang.org/u/skypuppy)\
**Replies:** 2\
**Last updated:** [September 25, 2021, 10:10am UTC](https://discourse.julialang.org/t/anyone-experimented-with-jetson-nanos/68738 "2021-09-25T10:10:12Z")

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Before I buy half a dozen more Nano’s :slight\_smile: has anyone tested Julia with the GPU’s on the Nano’s? Or Xaviers?

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## [I"m just starting. julia 1.6 on vscode](https://discourse.julialang.org/t/i-m-just-starting-julia-1-6-on-vscode/68728)

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**Author:** [@boyilu266](https://discourse.julialang.org/u/boyilu266)\
**Replies:** 3\
**Last updated:** [September 25, 2021, 6:58am UTC](https://discourse.julialang.org/t/i-m-just-starting-julia-1-6-on-vscode/68728 "2021-09-25T06:58:20Z")

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what am i doing wrong please?

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## [MultiJuMP.jl - linear models](https://discourse.julialang.org/t/multijump-jl-linear-models/68695)

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**Author:** [@s154428](https://discourse.julialang.org/u/s154428)\
**Replies:** 4\
**Last updated:** [September 25, 2021, 5:17am UTC](https://discourse.julialang.org/t/multijump-jl-linear-models/68695 "2021-09-25T05:17:36Z")

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Hi I’m solving a multi objective MILP with two objectives and I’m using the package MultiJuMP.jl. When solving linear models the are two methods in MultiJuMP a WeightedSum and EpsilonCons. Why should I not provide the…

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## [I can't update Flux to the latest version, probably due to a package compat constraint. How do I fix this?](https://discourse.julialang.org/t/i-cant-update-flux-to-the-latest-version-probably-due-to-a-package-compat-constraint-how-do-i-fix-this/68672)

<div class="topic-metadata">

**Author:** [@DevJac](https://discourse.julialang.org/u/DevJac)\
**Replies:** 2\
**Last updated:** [September 25, 2021, 3:09am UTC](https://discourse.julialang.org/t/i-cant-update-flux-to-the-latest-version-probably-due-to-a-package-compat-constraint-how-do-i-fix-this/68672 "2021-09-25T03:09:24Z")

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I recently got a NVIDIA GPU and wanted to run some of my old Flux code, but there is a bug with the older version of Flux and I cannot get it to work. Long story short, I need to update to the latest version of Flux. Exp…

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