# New to Julia

**URL:** https://discourse.julialang.org/c/first-steps/8.md?page=56

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**Page:** 57

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## [Why is ' the conjugate transpose of a matrix?](https://discourse.julialang.org/t/why-is-the-conjugate-transpose-of-a-matrix/109450)

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**Author:** [@AwesomeQuest](https://discourse.julialang.org/u/AwesomeQuest)\
**Replies:** 13\
**Last updated:** [January 31, 2024, 9:21pm UTC](https://discourse.julialang.org/t/why-is-the-conjugate-transpose-of-a-matrix/109450 "2024-01-31T21:21:29Z")

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Why is the ' operator the conjugate transpose operator and not just the transpose operator or the conjugate operator?

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## [Switching to Juliaup for installation](https://discourse.julialang.org/t/switching-to-juliaup-for-installation/109525)

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**Author:** [@cby](https://discourse.julialang.org/u/cby)\
**Replies:** 2\
**Last updated:** [January 31, 2024, 8:29pm UTC](https://discourse.julialang.org/t/switching-to-juliaup-for-installation/109525 "2024-01-31T20:29:03Z")

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I’m having trouble figuring out how to switch to Juliaup for installation of a new version of Julia with Visual Studio Code. I ran curl -fsSL https://install.julialang.org | sh julia +1.10 At this point I saw that the…

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## [Kronecker doesn't work, kron yes, in this case](https://discourse.julialang.org/t/kronecker-doesnt-work-kron-yes-in-this-case/109474)

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**Author:** [@Enlil50](https://discourse.julialang.org/u/Enlil50)\
**Replies:** 8\
**Last updated:** [January 31, 2024, 7:44pm UTC](https://discourse.julialang.org/t/kronecker-doesnt-work-kron-yes-in-this-case/109474 "2024-01-31T19:44:35Z")

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This is the program I made: import Random using LinearAlgebra N::Int64 = 100 matr\_A = Array{Float64}(undef, N, N) matr\_B = Array{Float64}(undef, N, N) matr\_C = Array{Float64}(undef, N\*N, N\*N) Random.seed!(1) for j = …

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## [Right way to run external program in parallel?](https://discourse.julialang.org/t/right-way-to-run-external-program-in-parallel/109490)

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**Author:** [@Tetrakai](https://discourse.julialang.org/u/Tetrakai)\
**Replies:** 3\
**Last updated:** [January 31, 2024, 4:21am UTC](https://discourse.julialang.org/t/right-way-to-run-external-program-in-parallel/109490 "2024-01-31T04:21:21Z")

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I could not figure this out all day, until finally this answer saved me: run(\`bash -c """cd temp\_dir && some\_cmd"""\`) Is there a better way to do this? In particular I want to run a program designed to log results s…

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## ['Sol' not defined upon opening Julia?](https://discourse.julialang.org/t/sol-not-defined-upon-opening-julia/109480)

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**Author:** [@deweyfinn](https://discourse.julialang.org/u/deweyfinn)\
**Replies:** 15\
**Last updated:** [January 31, 2024, 3:27am UTC](https://discourse.julialang.org/t/sol-not-defined-upon-opening-julia/109480 "2024-01-31T03:27:43Z")

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Hi. I have this code I am trying to make for graphing the trajectory of a thrown baton. The script involves a mass matrix (of the baton) being multiplied by dydt to show its trajectory. My problem comes from the use of …

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## [Defining a function that modifies its argument in place defines a new function instead](https://discourse.julialang.org/t/defining-a-function-that-modifies-its-argument-in-place-defines-a-new-function-instead/109462)

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**Author:** [@keynescoefen](https://discourse.julialang.org/u/keynescoefen)\
**Replies:** 2\
**Last updated:** [January 30, 2024, 5:42pm UTC](https://discourse.julialang.org/t/defining-a-function-that-modifies-its-argument-in-place-defines-a-new-function-instead/109462 "2024-01-30T17:42:33Z")

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Hello! I have the following function using SpecialFunctions function CDFFoldedNormal(x,μ,σ) #follow the example: https://en.wikipedia.org/wiki/Folded\_normal\_distribution #Note that the folded normal is NOT the h…

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## [Julia installation, Linux](https://discourse.julialang.org/t/julia-installation-linux/109421)

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**Author:** [@Enlil50](https://discourse.julialang.org/u/Enlil50)\
**Replies:** 4\
**Last updated:** [January 29, 2024, 8:10pm UTC](https://discourse.julialang.org/t/julia-installation-linux/109421 "2024-01-29T20:10:31Z")

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I suck installing things. I better write them from scratch. So, I runned the script on the Julia site. At the end it said it was successful: Now installing Juliaup Installing Julia 1.10.0+0.x64.linux.gnu Configured the…

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## [Some\_thing in some\_list](https://discourse.julialang.org/t/some-thing-in-some-list/109327)

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**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 11\
**Last updated:** [January 29, 2024, 5:13pm UTC](https://discourse.julialang.org/t/some-thing-in-some-list/109327 "2024-01-29T17:13:25Z")

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I am from matlab. Codes like if some\_thing in some\_list is new to me. It of course makes coding simple, but what is the price? I guess julia just checks the elements of some\_list one by one to see whether some\_thing …

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## [Errors in creating a small, multi-file project with one module](https://discourse.julialang.org/t/errors-in-creating-a-small-multi-file-project-with-one-module/109324)

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**Author:** [@Spydercrawler](https://discourse.julialang.org/u/Spydercrawler)\
**Replies:** 10\
**Last updated:** [January 29, 2024, 4:33pm UTC](https://discourse.julialang.org/t/errors-in-creating-a-small-multi-file-project-with-one-module/109324 "2024-01-29T16:33:09Z")

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Hello! I am a new Julia user, using v1.10, and am struggling a bit to fully understand how to get multiple code files to work together. Specifically, I am finding that editing files can throw errors, and my using statem…

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## [Change location of .julia](https://discourse.julialang.org/t/change-location-of-julia/21540)

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**Author:** [@Jack\_Stillwell](https://discourse.julialang.org/u/Jack_Stillwell)\
**Replies:** 12\
**Last updated:** [January 29, 2024, 2:18pm UTC](https://discourse.julialang.org/t/change-location-of-julia/21540 "2024-01-29T14:18:11Z")

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I am currently in the process of installing Julia in the ChromeOS shell. I have julia running OK, but I cannot seem to install some packages because the .julia directory is located in the noexec home folder. I would like…

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## [Error creating a Dict with symbols as indices](https://discourse.julialang.org/t/error-creating-a-dict-with-symbols-as-indices/109367)

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**Author:** [@orebas](https://discourse.julialang.org/u/orebas)\
**Replies:** 4\
**Last updated:** [January 29, 2024, 10:02am UTC](https://discourse.julialang.org/t/error-creating-a-dict-with-symbols-as-indices/109367 "2024-01-29T10:02:59Z")

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I am trying to emulate some code I have been given, which returns a Dict that has model states from a ModelingToolkit model as indices. But the below code gives an error. Here’s the MWE: using ModelingToolkit functio…

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## [ERROR: 'path' appears to be a local path, but directory does not exist](https://discourse.julialang.org/t/error-path-appears-to-be-a-local-path-but-directory-does-not-exist/109362)

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**Author:** [@danielbl](https://discourse.julialang.org/u/danielbl)\
**Replies:** 3\
**Last updated:** [January 28, 2024, 6:03pm UTC](https://discourse.julialang.org/t/error-path-appears-to-be-a-local-path-but-directory-does-not-exist/109362 "2024-01-28T18:03:15Z")

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Hi all. This post concerns the following error: ERROR: 'path' appears to be a local path, but directory does not exist I am currently following this Readme for a Julia/Python program (BYU CCBlade.ji). I have tried both…

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## [How to change colormap for plotting with arrows()?](https://discourse.julialang.org/t/how-to-change-colormap-for-plotting-with-arrows/109323)

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**Author:** [@Midez](https://discourse.julialang.org/u/Midez)\
**Replies:** 4\
**Last updated:** [January 27, 2024, 12:49pm UTC](https://discourse.julialang.org/t/how-to-change-colormap-for-plotting-with-arrows/109323 "2024-01-27T12:49:33Z")

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Julia has an awesome documentation, including an example for arrows(). However I don’t figure, how to change the colormap that shows the strength of the arrows. I’d like to change it to :bluesreds. If you know how, let m…

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## [Minor issue with if statement and may about types?](https://discourse.julialang.org/t/minor-issue-with-if-statement-and-may-about-types/109326)

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**Author:** [@Wooheon](https://discourse.julialang.org/u/Wooheon)\
**Replies:** 5\
**Last updated:** [January 27, 2024, 3:03am UTC](https://discourse.julialang.org/t/minor-issue-with-if-statement-and-may-about-types/109326 "2024-01-27T03:03:29Z")

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Hello, I just tried to make the following function. function CRRA\_bernoulli(ω::Float16,x::Int16) if ω == 1.00 val = log( exp(1), x ) else val = ( x / ( 1 - ω ) ) ^ ( 1 - ω ) end return va…

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## [How to install packages on an offline cluster?](https://discourse.julialang.org/t/how-to-install-packages-on-an-offline-cluster/109293)

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**Author:** [@baizhan](https://discourse.julialang.org/u/baizhan)\
**Replies:** 7\
**Last updated:** [January 26, 2024, 2:00pm UTC](https://discourse.julialang.org/t/how-to-install-packages-on-an-offline-cluster/109293 "2024-01-26T14:00:16Z")

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I’m trying to use julia on a cluster, which does not have usual network, so I have to install the packages offlinely. I have read several post regarding this problem, it seems that I should upload the entire ~/.julia …

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## [zeros(Float64, 2) or zeros(2, Float64)](https://discourse.julialang.org/t/zeros-float64-2-or-zeros-2-float64/109283)

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**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 5\
**Last updated:** [January 26, 2024, 6:56am UTC](https://discourse.julialang.org/t/zeros-float64-2-or-zeros-2-float64/109283 "2024-01-26T06:56:56Z")

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julia\> a = zeros(Float64, 2) 2-element Vector{Float64}: 0.0 0.0 julia\> a = zeros(2, Float64 ) ERROR: MethodError: no method matching zeros(::Int64, ::Type{Float64}) Closest candidates are: zeros(::Union{Integer,…

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## [GLMakie remote animations through ssh](https://discourse.julialang.org/t/glmakie-remote-animations-through-ssh/109270)

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**Author:** [@lpv](https://discourse.julialang.org/u/lpv)\
**Replies:** 3\
**Last updated:** [January 25, 2024, 10:26pm UTC](https://discourse.julialang.org/t/glmakie-remote-animations-through-ssh/109270 "2024-01-25T22:26:27Z")

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Hello! I am trying to create an animation with the results from a simulation remotely through “ssh -X”. When doing locally, it is quite fast. Through the ssh, it get extremely slow. It would be easier for me to simply g…

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## [Huge memory allocation](https://discourse.julialang.org/t/huge-memory-allocation/109273)

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**Author:** [@jisutich](https://discourse.julialang.org/u/jisutich)\
**Replies:** 17\
**Last updated:** [January 25, 2024, 10:16pm UTC](https://discourse.julialang.org/t/huge-memory-allocation/109273 "2024-01-25T22:16:15Z")

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Hi, I am trying to do some calculation which involves large array (float64 arrays with length 2^30). The array is large but I think still acceptable. However, when I tried to run the codes within some loops, the memory …

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## [Create an implicit environment with package directories](https://discourse.julialang.org/t/create-an-implicit-environment-with-package-directories/109207)

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**Author:** [@francis-gagnon](https://discourse.julialang.org/u/francis-gagnon)\
**Replies:** 15\
**Last updated:** [January 25, 2024, 8:53pm UTC](https://discourse.julialang.org/t/create-an-implicit-environment-with-package-directories/109207 "2024-01-25T20:53:18Z")

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The manual mention that it’s possible to create an implicit environnement with package directories (i.e. directories without Project.toml files). Like @plafer in this post, I tried to replicate the example in the manual …

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## [Nastran OP2 and BDF](https://discourse.julialang.org/t/nastran-op2-and-bdf/108425)

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**Author:** [@Jacob53101](https://discourse.julialang.org/u/Jacob53101)\
**Replies:** 1\
**Last updated:** [January 25, 2024, 8:17pm UTC](https://discourse.julialang.org/t/nastran-op2-and-bdf/108425 "2024-01-25T20:17:39Z")

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I’m trying to work with nx nastran bdf and op2 files using julia. There’s a library in python called pyNastran that can parse these nastran files really well and save them as hdf5 files. My plan is to read these hdf5 fil…

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## [{} in function names](https://discourse.julialang.org/t/in-function-names/109240)

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**Author:** [@jiang\_ming\_zhang](https://discourse.julialang.org/u/jiang_ming_zhang)\
**Replies:** 2\
**Last updated:** [January 25, 2024, 11:05am UTC](https://discourse.julialang.org/t/in-function-names/109240 "2024-01-25T11:05:24Z")

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I see many functions or constructors with {} in their names. julia\> NTuple{4,Int64}((1,2,3,4)) (1, 2, 3, 4) julia\> function myfun{2}(x,y) return x + y end ERROR: UndefVarError: \`myfun\` not defined Stacktr…

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## [Convergence behavior in MATLAB vs Julia](https://discourse.julialang.org/t/convergence-behavior-in-matlab-vs-julia/109113)

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**Author:** [@Gast](https://discourse.julialang.org/u/Gast)\
**Replies:** 12\
**Last updated:** [January 25, 2024, 8:13am UTC](https://discourse.julialang.org/t/convergence-behavior-in-matlab-vs-julia/109113 "2024-01-25T08:13:07Z")

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I am facing challenges in replicating a nonlinear unconstrained dynamic optimization problem originally coded in MATLAB using Julia. While the convergence of the algorithm is successful in MATLAB, I cannot achieve conver…

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## [\#jsoc-mentors](https://discourse.julialang.org/t/jsoc-mentors/109213)

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**Author:** [@Hiwa](https://discourse.julialang.org/u/Hiwa)\
**Replies:** 1\
**Last updated:** [January 24, 2024, 8:54pm UTC](https://discourse.julialang.org/t/jsoc-mentors/109213 "2024-01-24T20:54:09Z")

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Hello I need to be added to #jsoc-mentors and to mentor students volunteerly, Can you please add me to the list and the group

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## [Confused by package directory environments](https://discourse.julialang.org/t/confused-by-package-directory-environments/26194)

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**Author:** [@evanfields](https://discourse.julialang.org/u/evanfields)\
**Replies:** 6\
**Last updated:** [October 21, 2021, 5:26pm UTC](https://discourse.julialang.org/t/confused-by-package-directory-environments/26194 "2021-10-21T17:26:14Z")

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I’m trying to better understand code loading, so reading that section of the manual. The manual describes package directory environments: A package directory is a directory containing the source trees of a set of packag…

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## [Recommended AI engine for translating between Julia, Python and Wolfram Mathematica](https://discourse.julialang.org/t/recommended-ai-engine-for-translating-between-julia-python-and-wolfram-mathematica/109152)

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**Author:** [@Shamrock\_812](https://discourse.julialang.org/u/Shamrock_812)\
**Replies:** 4\
**Last updated:** [January 23, 2024, 5:00pm UTC](https://discourse.julialang.org/t/recommended-ai-engine-for-translating-between-julia-python-and-wolfram-mathematica/109152 "2024-01-23T17:00:12Z")

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Hi, New to Julia and trying to translate Julia code to Python and to Wolfram Mathematica and the other way around with ChatGPT however the result is buggy and requires too much overhead to deal with. Any recommendation…

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## [Date axis in Makie](https://discourse.julialang.org/t/date-axis-in-makie/63430)

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**Author:** [@danielw2904](https://discourse.julialang.org/u/danielw2904)\
**Replies:** 11\
**Last updated:** [January 23, 2024, 11:33am UTC](https://discourse.julialang.org/t/date-axis-in-makie/63430 "2024-01-23T11:33:14Z")

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I was looking into Makie for plotting some time series but could only find an open issue for having dates on one of the axes. The first suggested fix does not work for me (I get an error when calling lines) and the secon…

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## [Performance tips for differential equation RHS](https://discourse.julialang.org/t/performance-tips-for-differential-equation-rhs/108934)

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**Author:** [@madeline](https://discourse.julialang.org/u/madeline)\
**Replies:** 22\
**Last updated:** [January 23, 2024, 5:11am UTC](https://discourse.julialang.org/t/performance-tips-for-differential-equation-rhs/108934 "2024-01-23T05:11:55Z")

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Hello, I’ve been working on a project which relies on being able to swiftly solve something like the following system: using DifferentialEquations using StaticArrays using Einsum using Random using Graphs function watt…

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## [Concatenate Vector of Vector with differents length](https://discourse.julialang.org/t/concatenate-vector-of-vector-with-differents-length/109071)

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**Author:** [@blociss](https://discourse.julialang.org/u/blociss)\
**Replies:** 8\
**Last updated:** [January 22, 2024, 5:37pm UTC](https://discourse.julialang.org/t/concatenate-vector-of-vector-with-differents-length/109071 "2024-01-22T17:37:01Z")

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Consider the following vector: v = \[ (1, \[\[11, 11, 11\], \[12, 12, 12\]\]), (2, \[\[21, 21, 21\]), (3, \[\[31, 31, 31\], \[32, 32, 32\]\]), (4, \[\[41, 41, 41\]), \] I want to get 4-element Vector{Any}: \[\[11, 11, 11\], …

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## [Best way to Re-Install Julia on new computer?](https://discourse.julialang.org/t/best-way-to-re-install-julia-on-new-computer/106103)

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**Author:** [@CosmoProf](https://discourse.julialang.org/u/CosmoProf)\
**Replies:** 32\
**Last updated:** [January 22, 2024, 7:29am UTC](https://discourse.julialang.org/t/best-way-to-re-install-julia-on-new-computer/106103 "2024-01-22T07:29:07Z")

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Hi, my computer had to be swapped for a new one, and I need to re-install Julia from scratch, making sure that all of my old Julia programs will still run correctly. The first time I installed Julia, I had a litany of p…

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## [ADAM crash](https://discourse.julialang.org/t/adam-crash/109040)

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**Author:** [@Anders\_Holtsberg](https://discourse.julialang.org/u/Anders_Holtsberg)\
**Replies:** 5\
**Last updated:** [January 21, 2024, 9:04pm UTC](https://discourse.julialang.org/t/adam-crash/109040 "2024-01-21T21:04:39Z")

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I am getting started with Flux and learning machine learning and Julia at the same time. So I had a look at some examples and loading MNIST and running stuff in Jupyter and that works fine for me. I started experimenting…

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