# Latest

**URL:** https://discourse.julialang.org/latest.md?page=911

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

**Page:** 912

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## [Failing to precompile Plots due to LoadError](https://discourse.julialang.org/t/failing-to-precompile-plots-due-to-loaderror/77232)

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**Author:** [@fredrikpaues](https://discourse.julialang.org/u/fredrikpaues)\
**Replies:** 12\
**Last updated:** [September 28, 2022, 9:31am UTC](https://discourse.julialang.org/t/failing-to-precompile-plots-due-to-loaderror/77232 "2022-09-28T09:31:51Z")

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I’m trying to set up Julia on my work computer and encounter a LoadError when I try to precompile Plots.jl. Help would be much appreciated! I’m on Windows 10 and use Julia 1.7.2. julia\> import Pkg; Pkg.precompile() Pre…

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## [The best way to create a AbstractArray with known first demension size](https://discourse.julialang.org/t/the-best-way-to-create-a-abstractarray-with-known-first-demension-size/87904)

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**Author:** [@Brian1](https://discourse.julialang.org/u/Brian1)\
**Replies:** 1\
**Last updated:** [September 28, 2022, 9:08am UTC](https://discourse.julialang.org/t/the-best-way-to-create-a-abstractarray-with-known-first-demension-size/87904 "2022-09-28T09:08:12Z")

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What is the best way to preallocate a Array with knowning the first demension size(that is 5), while keeping unchanged for other demension: test\_func(x::Array{T,N}) = Array{T,N}(undef,5,size(x)\[2:end\]...) a\_vec = \[1,2,…

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## [Calculus With Julia Book](https://discourse.julialang.org/t/calculus-with-julia-book/87905)

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**Author:** [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)\
**Replies:** 0\
**Last updated:** [September 28, 2022, 8:29am UTC](https://discourse.julialang.org/t/calculus-with-julia-book/87905 "2022-09-28T08:29:05Z")

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Hi all, I think it is still about Julia, but including a physical book. I was reading Calculus With Julia tutorial all this time to help me learning Calculus, still newbie and just a beginner mathematics student. https…

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## [Bikeshedding: Name of package with AbstractStrings based on NTuples](https://discourse.julialang.org/t/bikeshedding-name-of-package-with-abstractstrings-based-on-ntuples/87881)

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**Author:** [@mkitti](https://discourse.julialang.org/u/mkitti)\
**Replies:** 15\
**Last updated:** [September 28, 2022, 7:48am UTC](https://discourse.julialang.org/t/bikeshedding-name-of-package-with-abstractstrings-based-on-ntuples/87881 "2022-09-28T07:48:31Z")

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I’m in the process of creating a new package for strings based on NTuples. It is similar in concept to InlineStrings.jl, but it uses NTuple{N,UInt8} instead of primitives. It allows for more variation in N. In part, it i…

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## [Is there a way to creat a function, which can be called on the right of arguments?](https://discourse.julialang.org/t/is-there-a-way-to-creat-a-function-which-can-be-called-on-the-right-of-arguments/87901)

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**Author:** [@Brian1](https://discourse.julialang.org/u/Brian1)\
**Replies:** 5\
**Last updated:** [September 28, 2022, 7:45am UTC](https://discourse.julialang.org/t/is-there-a-way-to-creat-a-function-which-can-be-called-on-the-right-of-arguments/87901 "2022-09-28T07:45:44Z")

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A = \[\[1,2,3\] \[2,3,4\] #I can call adjoint like this A' So, is there way I can do this? ⁻¹(x::Matrix) = inv(x) (A' \* A)⁻¹

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## [Problem with first example with Flux](https://discourse.julialang.org/t/problem-with-first-example-with-flux/87899)

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**Author:** [@Richard\_Wright](https://discourse.julialang.org/u/Richard_Wright)\
**Replies:** 1\
**Last updated:** [September 28, 2022, 7:13am UTC](https://discourse.julialang.org/t/problem-with-first-example-with-flux/87899 "2022-09-28T07:13:44Z")

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Hello, I am trying the very first example in flux from Overview · Flux. The code is given below. It works fine when hcat(0:5...) but doesn’t when hcat(0:6...). Why? using Flux using Flux: train! import Random Rando…

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## [Confusion about type parameterization and method applicability](https://discourse.julialang.org/t/confusion-about-type-parameterization-and-method-applicability/87874)

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**Author:** [@Mark\_Nahabedian](https://discourse.julialang.org/u/Mark_Nahabedian)\
**Replies:** 9\
**Last updated:** [September 28, 2022, 12:37am UTC](https://discourse.julialang.org/t/confusion-about-type-parameterization-and-method-applicability/87874 "2022-09-28T00:37:39Z")

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I define the type @kwdef mutable struct Tablet{T} id = nothing a::T # ... end My program mostly operates on Vectors of these. One thing I need to do is jusxtopose such vectors to make longer vectors. I ov…

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## [Result index of attribute](https://discourse.julialang.org/t/result-index-of-attribute/87891)

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**Author:** [@Zizilabg](https://discourse.julialang.org/u/Zizilabg)\
**Replies:** 1\
**Last updated:** [September 27, 2022, 11:41pm UTC](https://discourse.julialang.org/t/result-index-of-attribute/87891 "2022-09-27T23:41:01Z")

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Hello, I wrote a model about Julia which contains 3 constraints. If I test one constraint at a time, each one works. But if I run the whole program, I get the following error message: Has anyone had this problem bef…

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## [Create static vector of variable lenght in gpu kernel](https://discourse.julialang.org/t/create-static-vector-of-variable-lenght-in-gpu-kernel/87863)

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**Author:** [@ykkan](https://discourse.julialang.org/u/ykkan)\
**Replies:** 2\
**Last updated:** [September 27, 2022, 8:59pm UTC](https://discourse.julialang.org/t/create-static-vector-of-variable-lenght-in-gpu-kernel/87863 "2022-09-27T20:59:10Z")

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Are there any ways to create a static vector of variable length for each thread in a gpu kernel? I tried this but it didn’t work. function dosomething(n) vec = @MVector zeros(n) end @cuda threads=5 dosomething(n) …

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## [Problem with Symbolic package: computation of symbolic gradient](https://discourse.julialang.org/t/problem-with-symbolic-package-computation-of-symbolic-gradient/87882)

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**Author:** [@Luca](https://discourse.julialang.org/u/Luca)\
**Replies:** 1\
**Last updated:** [September 27, 2022, 8:10pm UTC](https://discourse.julialang.org/t/problem-with-symbolic-package-computation-of-symbolic-gradient/87882 "2022-09-27T20:10:45Z")

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Dear all, I’m trying to use Symbolics package in order to implement the symbolic computation of the gradient of a function. For instance given sin(8.0\*x1\*x2), I want to compute the partial derivative w.r.t. x1. I implem…

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## [Invalidation free copyto! depending on destination?](https://discourse.julialang.org/t/invalidation-free-copyto-depending-on-destination/87824)

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**Author:** [@longemen3000](https://discourse.julialang.org/u/longemen3000)\
**Replies:** 1\
**Last updated:** [September 27, 2022, 8:12pm UTC](https://discourse.julialang.org/t/invalidation-free-copyto-depending-on-destination/87824 "2022-09-27T20:12:21Z")

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Hi. i have a type that is not a subtype of AbstractArray, but it has a notion of size: #basically, vector + metadata struct SingleParam{T,M} names::Vector{String} values::Vector{T} #same size as names metadata::M …

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## [\[ANN\] Julia back-end for LFortran](https://discourse.julialang.org/t/ann-julia-back-end-for-lfortran/87859)

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**Author:** [@lucifer1004](https://discourse.julialang.org/u/lucifer1004)\
**Replies:** 4\
**Last updated:** [September 27, 2022, 7:53pm UTC](https://discourse.julialang.org/t/ann-julia-back-end-for-lfortran/87859 "2022-09-27T19:53:51Z")

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This is not a Julia package, but is very related. I just implemented a Julia back-end for the LFortran project. Since it is still very primitive, it would be great if more users could try it and submit issues or provide…

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## [Transfer elements of an array to a shared array](https://discourse.julialang.org/t/transfer-elements-of-an-array-to-a-shared-array/87746)

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**Author:** [@jisutich](https://discourse.julialang.org/u/jisutich)\
**Replies:** 7\
**Last updated:** [September 27, 2022, 7:35pm UTC](https://discourse.julialang.org/t/transfer-elements-of-an-array-to-a-shared-array/87746 "2022-09-27T19:35:05Z")

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Hi, Suppose I have a SharedArray and now I have a normal vector which contains some values. I want to update the elements of my Shared Array by this vector. How to do it? Basically I have sample code using Distributed …

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## [Makie - improving performance with animations?](https://discourse.julialang.org/t/makie-improving-performance-with-animations/87478)

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**Author:** [@rkube](https://discourse.julialang.org/u/rkube)\
**Replies:** 4\
**Last updated:** [September 27, 2022, 7:21pm UTC](https://discourse.julialang.org/t/makie-improving-performance-with-animations/87478 "2022-09-27T19:21:19Z")

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Hi, I’m looking into animating results from a kinetic simulation using makie and got some basic animations going. Now I’m trying to improve about performance. This script kinetic\_anim.jl · GitHub animates the trajecto…

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## [Running Julia in Terminal vs. VsCode](https://discourse.julialang.org/t/running-julia-in-terminal-vs-vscode/87873)

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**Author:** [@mengxiaoliu](https://discourse.julialang.org/u/mengxiaoliu)\
**Replies:** 2\
**Last updated:** [September 27, 2022, 3:10pm UTC](https://discourse.julialang.org/t/running-julia-in-terminal-vs-vscode/87873 "2022-09-27T15:10:34Z")

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Hello, I run Julia on MacBook Air (M2, 2022) and am wondering if there is any difference between running Julia codes in VSCode versus from the Terminal. Thanks you.

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## [Symbol in type signature?](https://discourse.julialang.org/t/symbol-in-type-signature/87887)

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**Author:** [@Nathan\_Boyer](https://discourse.julialang.org/u/Nathan_Boyer)\
**Replies:** 2\
**Last updated:** [September 27, 2022, 7:15pm UTC](https://discourse.julialang.org/t/symbol-in-type-signature/87887 "2022-09-27T19:15:51Z")

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The Polynomial type from the Polynomials package has a symbol in its type signature that I don’t understand. julia\> typeof(Polynomial(\[1,2\])) Polynomial{Int64, :x} julia\> typeof(Polynomial(\[1,2\], :s)) Polynomial{Int64,…

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## [Difference between multiprocessors and multithreads](https://discourse.julialang.org/t/difference-between-multiprocessors-and-multithreads/87884)

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**Author:** [@jisutich](https://discourse.julialang.org/u/jisutich)\
**Replies:** 2\
**Last updated:** [September 27, 2022, 7:13pm UTC](https://discourse.julialang.org/t/difference-between-multiprocessors-and-multithreads/87884 "2022-09-27T19:13:18Z")

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Hi, I used to use package Distributed to do parallel computation. I may require multiple processors by addprocs() and use pmap to execute a function f on multiple cpus. But I just realize that Julia also provides multit…

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## [How to get a list of built-in functions in a package and a short description?](https://discourse.julialang.org/t/how-to-get-a-list-of-built-in-functions-in-a-package-and-a-short-description/87711)

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**Author:** [@ChrM](https://discourse.julialang.org/u/ChrM)\
**Replies:** 4\
**Last updated:** [September 27, 2022, 5:40pm UTC](https://discourse.julialang.org/t/how-to-get-a-list-of-built-in-functions-in-a-package-and-a-short-description/87711 "2022-09-27T17:40:46Z")

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Is it possible to get a list of the built-in functions within a package along with a brief description for each function? For example, in the Julia REPL, we can load the Econometrics package using Econometrics and then …

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## [What is the correct order to use factorization matrices in multiplication?](https://discourse.julialang.org/t/what-is-the-correct-order-to-use-factorization-matrices-in-multiplication/85194)

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**Author:** [@Amro](https://discourse.julialang.org/u/Amro)\
**Replies:** 28\
**Last updated:** [September 27, 2022, 4:54pm UTC](https://discourse.julialang.org/t/what-is-the-correct-order-to-use-factorization-matrices-in-multiplication/85194 "2022-09-27T16:54:17Z")

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I tried to have the result of \`\` but it gave error. So, I tried adj\_factor.L\*adj\_factor.U\*adj\_factor.F\*V but it gave different result with adj\*V. Could you please tell me what is the correct order of L,U,P to have the s…

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## [What makes bash forget the environment variable?](https://discourse.julialang.org/t/what-makes-bash-forget-the-environment-variable/87821)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 21\
**Last updated:** [September 27, 2022, 4:16pm UTC](https://discourse.julialang.org/t/what-makes-bash-forget-the-environment-variable/87821 "2022-09-27T16:16:28Z")

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My bash knows what PATH is: pkonl@Hedwig MINGW64 ~/ (main)$ echo $PATH /mingw64/bin:/usr/bin.... …

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## [Efficiently copying a tree with shared children](https://discourse.julialang.org/t/efficiently-copying-a-tree-with-shared-children/87787)

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**Author:** [@MilesCranmer](https://discourse.julialang.org/u/MilesCranmer)\
**Replies:** 20\
**Last updated:** [September 27, 2022, 4:07pm UTC](https://discourse.julialang.org/t/efficiently-copying-a-tree-with-shared-children/87787 "2022-09-27T16:07:35Z")

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What is the most efficient way to copy a tree with shared children? While this is technically a graph rather than a tree, here there is a clear root node and directionality, so it’s more intuitive to think of it as a tre…

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## [Tar for files?](https://discourse.julialang.org/t/tar-for-files/87422)

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**Author:** [@marllos](https://discourse.julialang.org/u/marllos)\
**Replies:** 5\
**Last updated:** [September 27, 2022, 3:45pm UTC](https://discourse.julialang.org/t/tar-for-files/87422 "2022-09-27T15:45:57Z")

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Hello everyone. I really liked the idea of the Tar.jl package. Can you use them for files instead of a complete folder? I have code that generates many files, and it would be interesting to compress these files into a si…

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## [Interest in a Pure Julia Luigi Pipeline?](https://discourse.julialang.org/t/interest-in-a-pure-julia-luigi-pipeline/87729)

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**Author:** [@mrufsvold](https://discourse.julialang.org/u/mrufsvold)\
**Replies:** 5\
**Last updated:** [September 27, 2022, 3:09pm UTC](https://discourse.julialang.org/t/interest-in-a-pure-julia-luigi-pipeline/87729 "2022-09-27T15:09:35Z")

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My company often uses Luigi to manage complex pipelines. We are doing more and more programming in Julia here, so I’ve been kicking around the idea of a native Julia solution for defining and managing a pipeline. Would …

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## [Block Sparse Matrix](https://discourse.julialang.org/t/block-sparse-matrix/81465)

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**Author:** [@00shiv](https://discourse.julialang.org/u/00shiv)\
**Replies:** 2\
**Last updated:** [September 27, 2022, 3:02pm UTC](https://discourse.julialang.org/t/block-sparse-matrix/81465 "2022-09-27T15:02:54Z")

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I would like to deal with very large sparse matrices with dense sub-blocks; for example, block arrow-head matrices, or a block periodic tridiagonal matrices. I know about the BlockArrays package. That supports blocking …

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## [How to use/initialize Zygote.Buffer](https://discourse.julialang.org/t/how-to-use-initialize-zygote-buffer/87653)

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**Author:** [@LeN3rd](https://discourse.julialang.org/u/LeN3rd)\
**Replies:** 3\
**Last updated:** [September 27, 2022, 2:52pm UTC](https://discourse.julialang.org/t/how-to-use-initialize-zygote-buffer/87653 "2022-09-27T14:52:10Z")

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This is probably a common question, but when i use Zygote.Buffer i cannot assign values by doing buffer .= old\_data It throws the following: ERROR: MethodError: no method matching ndims(::Type{Zygote.Buffer{Float64, Ma…

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## [LibGit2 question](https://discourse.julialang.org/t/libgit2-question/87871)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 1\
**Last updated:** [September 27, 2022, 2:15pm UTC](https://discourse.julialang.org/t/libgit2-question/87871 "2022-09-27T14:15:26Z")

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The library LibGit2 is part of Julia, I think. How can I achieve the aquivalent of: git diff --name-only --cached using LibGit2? I tried: repo = LibGit2.GitRepo(".") LibGit2.diff\_files(repo, "main", "origin/…

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## [Inconsistency of \`?\` to get help: syntax: invalid identifier name "?"](https://discourse.julialang.org/t/inconsistency-of-to-get-help-syntax-invalid-identifier-name/55260)

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**Author:** [@samerb](https://discourse.julialang.org/u/samerb)\
**Replies:** 4\
**Last updated:** [September 27, 2022, 1:26pm UTC](https://discourse.julialang.org/t/inconsistency-of-to-get-help-syntax-invalid-identifier-name/55260 "2022-09-27T13:26:53Z")

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Sometimes I use ? to get help on a function. For a given function called f, I type ?f and then run the cell and it gives info for that function. But sometimes this doesn’t work. For example right now I have two different…

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## [Why is it so hard to install packages in julia from China?](https://discourse.julialang.org/t/why-is-it-so-hard-to-install-packages-in-julia-from-china/87566)

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**Author:** [@hanchend](https://discourse.julialang.org/u/hanchend)\
**Replies:** 12\
**Last updated:** [September 27, 2022, 1:00pm UTC](https://discourse.julialang.org/t/why-is-it-so-hard-to-install-packages-in-julia-from-china/87566 "2022-09-27T13:00:35Z")

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I just installed Julia, but its so difficult to use packages, I am about to freak out. always have errors of different kind. just wont work can anyone help me a little,there is no one around me who use julia, i really e…

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## [2D FFT convolution but get inaccurate results](https://discourse.julialang.org/t/2d-fft-convolution-but-get-inaccurate-results/87816)

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**Author:** [@maphdze](https://discourse.julialang.org/u/maphdze)\
**Replies:** 9\
**Last updated:** [September 27, 2022, 12:38pm UTC](https://discourse.julialang.org/t/2d-fft-convolution-but-get-inaccurate-results/87816 "2022-09-27T12:38:07Z")

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I am trying to calculate this convlution integral a(x)=\\int{\\varphi(x,x\\prime)}w(x\\prime)\\rm{d}\\it{V\\prime},where \\varphi(x,x\\prime) is a compact support kernel function with a radius \\ell. Currently, \\varphi(x,x\\prime) …

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## [Edgelist representation as array](https://discourse.julialang.org/t/edgelist-representation-as-array/49960)

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**Author:** [@SDA](https://discourse.julialang.org/u/SDA)\
**Replies:** 1\
**Last updated:** [September 27, 2022, 11:39am UTC](https://discourse.julialang.org/t/edgelist-representation-as-array/49960 "2022-09-27T11:39:15Z")

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I am wanting to get an edgelist from my graph that can then be used as a coordinate in 2D. using LightGraphs A = \[ 0 1 1 1 0 1 1 1 0 \] G = Graph(A) EL = collect(edges(G)) How can the edge list EL be converted to an ar…

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