# General Usage

**URL:** https://discourse.julialang.org/c/usage/6.md?page=673

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**Page:** 674

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## [DiffEqFlux.sciml\_train giving UndefVarError: ProgressLogging not defined](https://discourse.julialang.org/t/diffeqflux-sciml-train-giving-undefvarerror-progresslogging-not-defined/45478)

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**Author:** [@anon22248738](https://discourse.julialang.org/u/anon22248738)\
**Replies:** 7\
**Last updated:** [November 25, 2020, 1:31am UTC](https://discourse.julialang.org/t/diffeqflux-sciml-train-giving-undefvarerror-progresslogging-not-defined/45478 "2020-11-25T01:31:10Z")

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When running the Optimization of Ordinary Differential Equations tutorial in the DiffEqFlux documentation, I get the following error ERROR: LoadError: UndefVarError: ProgressLogging not defined Stacktrace: \[1\] default\_…

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## [Latest version of docs not published (github actions/TagBot)](https://discourse.julialang.org/t/latest-version-of-docs-not-published-github-actions-tagbot/50634)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 24\
**Last updated:** [November 24, 2020, 10:43pm UTC](https://discourse.julialang.org/t/latest-version-of-docs-not-published-github-actions-tagbot/50634 "2020-11-24T22:43:29Z")

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I released some days ago a new stable version of a package. The TagBot created the tag correctly, but the docs of the stable version were not released, and keep pointing to the previous version. The CI run of the docume…

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## [Character n-grams in array](https://discourse.julialang.org/t/character-n-grams-in-array/50630)

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**Author:** [@lorb24](https://discourse.julialang.org/u/lorb24)\
**Replies:** 6\
**Last updated:** [November 24, 2020, 8:28pm UTC](https://discourse.julialang.org/t/character-n-grams-in-array/50630 "2020-11-24T20:28:37Z")

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I’m trying to get the character n-grams for a list of words. For example: julia\> s = "apple" julia\> s=reduce(vcat, permutedims.(collect.(s))) \['a', 'p', 'p', 'l', 'e'\] julia\> ngram(s,n) = join(\[view(s,i:i+n-1) for i=1:l…

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## [Sum of Any - Why sum of empty set is not zero?](https://discourse.julialang.org/t/sum-of-any-why-sum-of-empty-set-is-not-zero/50706)

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**Author:** [@programista](https://discourse.julialang.org/u/programista)\
**Replies:** 5\
**Last updated:** [November 24, 2020, 7:57pm UTC](https://discourse.julialang.org/t/sum-of-any-why-sum-of-empty-set-is-not-zero/50706 "2020-11-24T19:57:19Z")

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Why sum of empty set is not zero ? julia\> eltype(dane) Any julia\> sum(dane\[:,9\]) 6.54132454e8 julia\> dane\[(mies20) .& (dane\[:,7\].==dealerzy\[1\]),9\] 1-element Array{Any,1}: 2032.0 julia\> dane\[(mies20) .& (dane\[:,7\].==dea…

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## [Setting correctly package dependencies](https://discourse.julialang.org/t/setting-correctly-package-dependencies/50703)

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**Author:** [@lrnv](https://discourse.julialang.org/u/lrnv)\
**Replies:** 9\
**Last updated:** [November 24, 2020, 6:24pm UTC](https://discourse.julialang.org/t/setting-correctly-package-dependencies/50703 "2020-11-24T18:24:44Z")

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Hey, I’m starting the developpement of a package, and i have errors in the CI that i dont get on my machine, without me understanding how to fix them. Look at the log there. Seems like some package ‘Artifacts’ has cont…

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## [Casting \`Vector{Complex{T}}\` to \`Vector{T}\` of twice the size](https://discourse.julialang.org/t/casting-vector-complex-t-to-vector-t-of-twice-the-size/50689)

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**Author:** [@jlbosse](https://discourse.julialang.org/u/jlbosse)\
**Replies:** 3\
**Last updated:** [November 24, 2020, 6:14pm UTC](https://discourse.julialang.org/t/casting-vector-complex-t-to-vector-t-of-twice-the-size/50689 "2020-11-24T18:14:49Z")

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I have an Vector of complex numbers and want to interpret it as a vector of real numbers with twice the length. Currently I allocate a new vector and then manually fill it, but I wonder if there is a faster way without …

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## [How to debug inlining fails?](https://discourse.julialang.org/t/how-to-debug-inlining-fails/50658)

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**Author:** [@dlfivefifty](https://discourse.julialang.org/u/dlfivefifty)\
**Replies:** 1\
**Last updated:** [November 24, 2020, 6:11pm UTC](https://discourse.julialang.org/t/how-to-debug-inlining-fails/50658 "2020-11-24T18:11:23Z")

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I have a trait based system in LazyArrays.jl that isn’t inlining, which seems to be breaking type inference. Are there any tips for debugging why this is? Sorry for the non-MWE but the code is below. For some reason @i…

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## [Problem saving SharedArrays with JLD type](https://discourse.julialang.org/t/problem-saving-sharedarrays-with-jld-type/44754)

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**Author:** [@gideonsimpson](https://discourse.julialang.org/u/gideonsimpson)\
**Replies:** 3\
**Last updated:** [November 24, 2020, 5:10pm UTC](https://discourse.julialang.org/t/problem-saving-sharedarrays-with-jld-type/44754 "2020-11-24T17:10:32Z")

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I’ve got the following issue. I generate data using the Distributed module, storing it in a SharedArray, and then dumping it to disk via FileIO. The problem I have is that if I save it as .jld when I try to load back i…

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## [Distributed Or , julia logicals operators](https://discourse.julialang.org/t/distributed-or-julia-logicals-operators/50698)

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**Author:** [@rapasite](https://discourse.julialang.org/u/rapasite)\
**Replies:** 0\
**Last updated:** [November 24, 2020, 5:03pm UTC](https://discourse.julialang.org/t/distributed-or-julia-logicals-operators/50698 "2020-11-24T17:03:25Z")

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I asked a question on https://julialang.org/slack/. Question was: Is there any way to write something like x == (4 | 5) witch return true if x == 4 or if x == 5? The regular answer is: x in (4,5) or any other way …

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## [Iterative, looping split-apply-combines in Julia](https://discourse.julialang.org/t/iterative-looping-split-apply-combines-in-julia/50654)

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**Author:** [@newtojulia1](https://discourse.julialang.org/u/newtojulia1)\
**Replies:** 17\
**Last updated:** [November 24, 2020, 3:45pm UTC](https://discourse.julialang.org/t/iterative-looping-split-apply-combines-in-julia/50654 "2020-11-24T15:45:19Z")

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I am new to Julia (and the forum - apologies on my formatting!) and struggling to implement complex split-apply-combine functions, in particular when these involve iterative looping across columns. I could really use som…

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## [Differential Equations Solve - top not defined](https://discourse.julialang.org/t/differential-equations-solve-top-not-defined/44510)

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**Author:** [@totorotoby](https://discourse.julialang.org/u/totorotoby)\
**Replies:** 21\
**Last updated:** [November 24, 2020, 2:57pm UTC](https://discourse.julialang.org/t/differential-equations-solve-top-not-defined/44510 "2020-11-24T14:57:24Z")

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When running using DifferentialEquations f(u,p,t) = 1.01\*u u0 = 1/2 tspan = (0.0,1.0) prob = ODEProblem(f,u0,tspan) sol = solve(prob, Tsit5(), reltol=1e-8, abstol=1e-8) As taken off the DifferentialEquations.jl Documen…

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## [Dynamic cluster without head node?](https://discourse.julialang.org/t/dynamic-cluster-without-head-node/49583)

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**Author:** [@Sukera](https://discourse.julialang.org/u/Sukera)\
**Replies:** 1\
**Last updated:** [November 23, 2020, 10:41pm UTC](https://discourse.julialang.org/t/dynamic-cluster-without-head-node/49583 "2020-11-23T22:41:51Z")

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Hi there, I’m looking for a sort of dynamically sized cluster manager, but without the requirement for a dedicated head node that’s responsible for adding and removing worker nodes. I know of ElasticManager from Cluster…

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## [How to parellalizing many matrix solves](https://discourse.julialang.org/t/how-to-parellalizing-many-matrix-solves/50603)

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**Author:** [@Pulpo](https://discourse.julialang.org/u/Pulpo)\
**Replies:** 5\
**Last updated:** [November 23, 2020, 10:44pm UTC](https://discourse.julialang.org/t/how-to-parellalizing-many-matrix-solves/50603 "2020-11-23T22:44:45Z")

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I am trying to solve many matrix equations Ax=b of fixed size. A simplified version of the code is as follows: function ser\_solve(A,b,res,nu) for i in(1:nu) res\[i,:\]=A\[i,:,:\]\\b\[i,:\] end return res; e…

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## [No syntax highlighting in the new vscode Jupyter notebook extension](https://discourse.julialang.org/t/no-syntax-highlighting-in-the-new-vscode-jupyter-notebook-extension/50602)

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**Author:** [@affans](https://discourse.julialang.org/u/affans)\
**Replies:** 4\
**Last updated:** [November 23, 2020, 10:13pm UTC](https://discourse.julialang.org/t/no-syntax-highlighting-in-the-new-vscode-jupyter-notebook-extension/50602 "2020-11-23T22:13:08Z")

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Upon launching the notebook, there is syntax highlighting (I am guessing default syntax highlighting for Python). As soon as it connects to the Julia kernel, there is no syntax highlighting at all. Running on WSL 2.

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## [Unit tests reports in xml](https://discourse.julialang.org/t/unit-tests-reports-in-xml/22415)

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**Author:** [@poldavezac](https://discourse.julialang.org/u/poldavezac)\
**Replies:** 1\
**Last updated:** [November 23, 2020, 9:37pm UTC](https://discourse.julialang.org/t/unit-tests-reports-in-xml/22415 "2020-11-23T21:37:12Z")

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I would like to report unit tests in junit format, this in order to integrate into a continuous integration tool (not Travis). Has anybody done such a thing successfully? I did find an oxinabox/TestReports.jl but it see…

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## [Jupyter Won't Spawn ENOENT, unable to export pdf](https://discourse.julialang.org/t/jupyter-wont-spawn-enoent-unable-to-export-pdf/50648)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 16\
**Last updated:** [November 23, 2020, 9:30pm UTC](https://discourse.julialang.org/t/jupyter-wont-spawn-enoent-unable-to-export-pdf/50648 "2020-11-23T21:30:06Z")

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I had Jupyter working for the first time yesterday, and was able use the latest version of Julia Pro, to run most files. Today though, It says something about unable to spawn ENOENT, and none of the features work. \> ~\\…

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## [Unsolvable dynamic dispatch in a \`for\` loop](https://discourse.julialang.org/t/unsolvable-dynamic-dispatch-in-a-for-loop/50643)

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**Author:** [@drarnau](https://discourse.julialang.org/u/drarnau)\
**Replies:** 3\
**Last updated:** [November 23, 2020, 9:11pm UTC](https://discourse.julialang.org/t/unsolvable-dynamic-dispatch-in-a-for-loop/50643 "2020-11-23T21:11:34Z")

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Hello, I posted about this problem last week. I think now I have the most simple example to illustrate it: function my2outputs(a::Float64, g::Function) myRange = LinRange(-10.0,10.0,100) myMax, myLoc = findmax(…

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## [Eigs on huge SparseArrays doesn't use all BLAS threads](https://discourse.julialang.org/t/eigs-on-huge-sparsearrays-doesnt-use-all-blas-threads/50626)

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**Author:** [@Ahmed\_Abouelkomsan](https://discourse.julialang.org/u/Ahmed_Abouelkomsan)\
**Replies:** 7\
**Last updated:** [November 23, 2020, 8:27pm UTC](https://discourse.julialang.org/t/eigs-on-huge-sparsearrays-doesnt-use-all-blas-threads/50626 "2020-11-23T20:27:29Z")

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Hi all, I am dealing with huge sparse arrays of dimensions greater than 10^6. I am interested in finding only few extremal eigenvalues. To this end, I tried to use the Arpack package but I noticed that if the size of th…

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## [How do I distribute Mamba mcmc function iterations on different processors?](https://discourse.julialang.org/t/how-do-i-distribute-mamba-mcmc-function-iterations-on-different-processors/50462)

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**Author:** [@EllieA](https://discourse.julialang.org/u/EllieA)\
**Replies:** 3\
**Last updated:** [November 23, 2020, 7:48pm UTC](https://discourse.julialang.org/t/how-do-i-distribute-mamba-mcmc-function-iterations-on-different-processors/50462 "2020-11-23T19:48:08Z")

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Hi all, I am new to Mamba package, I know that it has automated paralleling for different “chains” but as my data set is a huge one, I would like to distribute the iterations on different processors. Is it possible?

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## [Conversion, promotion, user API?](https://discourse.julialang.org/t/conversion-promotion-user-api/50629)

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**Author:** [@tamasgal](https://discourse.julialang.org/u/tamasgal)\
**Replies:** 12\
**Last updated:** [November 23, 2020, 6:14pm UTC](https://discourse.julialang.org/t/conversion-promotion-user-api/50629 "2020-11-23T18:14:44Z")

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I am struggling to find the right design due to the shear amount of possibilities, so I need help :wink: Given a type FooID, which is a simple number with a bit of additional convenience attributes (I added that to to s…

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## [Assign vector to slices and allocation](https://discourse.julialang.org/t/assign-vector-to-slices-and-allocation/49887)

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**Author:** [@cricci](https://discourse.julialang.org/u/cricci)\
**Replies:** 7\
**Last updated:** [November 23, 2020, 6:06pm UTC](https://discourse.julialang.org/t/assign-vector-to-slices-and-allocation/49887 "2020-11-23T18:06:50Z")

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I am trying to optimize my code by reducing all unnecessary memory allocation. In particular I have a some assignment I need to repeat many many times. Hence I pre-allocate all necessary vectors and matrices in order to …

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## [Code to calculate characteristic polynomial?](https://discourse.julialang.org/t/code-to-calculate-characteristic-polynomial/19903)

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**Author:** [@purplishrock](https://discourse.julialang.org/u/purplishrock)\
**Replies:** 5\
**Last updated:** [November 23, 2020, 3:27pm UTC](https://discourse.julialang.org/t/code-to-calculate-characteristic-polynomial/19903 "2020-11-23T15:27:43Z")

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I’m referring to det(\\lambda I - A) I’m not finding a function to calculate this (it’s charpoly in Matlab). Happy to write my own, just want to make sure i’m not duplicating effort. Thanks p.s. well actually i’m pro…

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## [Single colorbar for heatmap grid layout](https://discourse.julialang.org/t/single-colorbar-for-heatmap-grid-layout/50609)

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**Author:** [@martincornejo](https://discourse.julialang.org/u/martincornejo)\
**Replies:** 4\
**Last updated:** [November 23, 2020, 10:54am UTC](https://discourse.julialang.org/t/single-colorbar-for-heatmap-grid-layout/50609 "2020-11-23T10:54:29Z")

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Take for example: using Plots plot( heatmap(rand(10,10)), heatmap(rand(10,10)), heatmap(rand(10,10)), heatmap(rand(10,10)); layout=4 ) How could it be possible to have a single colorbar for all h…

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## [Animation slider in Pluto.jl](https://discourse.julialang.org/t/animation-slider-in-pluto-jl/50580)

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**Author:** [@Skoffer](https://discourse.julialang.org/u/Skoffer)\
**Replies:** 2\
**Last updated:** [November 23, 2020, 8:32am UTC](https://discourse.julialang.org/t/animation-slider-in-pluto-jl/50580 "2020-11-23T08:32:16Z")

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I wonder if this functionality already exists, that is why I am asking before trying to reinvent the bicycle. Is there an existing component to create a visual UI, which can run animation? What I have in mind, is some …

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## [Could this simple function go faster?](https://discourse.julialang.org/t/could-this-simple-function-go-faster/50034)

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**Author:** [@lrnv](https://discourse.julialang.org/u/lrnv)\
**Replies:** 15\
**Last updated:** [November 22, 2020, 7:46pm UTC](https://discourse.julialang.org/t/could-this-simple-function-go-faster/50034 "2020-11-22T19:46:52Z")

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Hi, First time ever writing julia code. I’ve spend some time trying to optimise this function, mainly making it type-stable, and separate some precomputations. But maybe this is not the best way to go. The resulting co…

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## [Distributed.pgenerate not working as documented](https://discourse.julialang.org/t/distributed-pgenerate-not-working-as-documented/50615)

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**Author:** [@marius311](https://discourse.julialang.org/u/marius311)\
**Replies:** 0\
**Last updated:** [November 23, 2020, 6:28am UTC](https://discourse.julialang.org/t/distributed-pgenerate-not-working-as-documented/50615 "2020-11-23T06:28:04Z")

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The docstring for Distributed.pgenerate says Results are returned in order as they become available. which is exactly what I need. However, it doesn’t seem to be working this way, instead, the results are only return…

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## [Copying a QR decomposition matrix Q is extremely slow](https://discourse.julialang.org/t/copying-a-qr-decomposition-matrix-q-is-extremely-slow/50430)

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**Author:** [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Replies:** 7\
**Last updated:** [November 22, 2020, 8:58am UTC](https://discourse.julialang.org/t/copying-a-qr-decomposition-matrix-q-is-extremely-slow/50430 "2020-11-22T08:58:40Z")

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This is on julia 1.5.3 julia\> f = qr(ones(100, 20), Val(true)); julia\> copy(f.Q); @time copy(f.Q); 0.057310 seconds (40.00 k allocations: 338.516 MiB, 10.85% gc time) julia\> copy(Array(f.Q)); @time copy(Array(f.Q));…

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## [How to do technical analysis charts / visualizations using Julia?](https://discourse.julialang.org/t/how-to-do-technical-analysis-charts-visualizations-using-julia/40562)

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**Author:** [@MaxHayden](https://discourse.julialang.org/u/MaxHayden)\
**Replies:** 8\
**Last updated:** [November 22, 2020, 10:09pm UTC](https://discourse.julialang.org/t/how-to-do-technical-analysis-charts-visualizations-using-julia/40562 "2020-11-22T22:09:44Z")

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I am trying to improve my financial research workflow and need some help figuring out how to create some custom charts/visualizations. I don’t like my current mish-mash of C++, R, Python, and some proprietary charting p…

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## [Way to make SharedArray over fixed length Strings?](https://discourse.julialang.org/t/way-to-make-sharedarray-over-fixed-length-strings/7082)

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**Author:** [@djsegal](https://discourse.julialang.org/u/djsegal)\
**Replies:** 15\
**Last updated:** [November 22, 2020, 1:56pm UTC](https://discourse.julialang.org/t/way-to-make-sharedarray-over-fixed-length-strings/7082 "2020-11-22T13:56:20Z")

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if you do SharedArray{AbstractString}(10, 1) you get the following error: ERROR: ArgumentError: type of SharedArray elements must be bits types, got AbstractString Is there a package for making fixed length strings to…

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## [Fonts with consistent ligature support for Julia](https://discourse.julialang.org/t/fonts-with-consistent-ligature-support-for-julia/43584)

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**Author:** [@pauljurczak](https://discourse.julialang.org/u/pauljurczak)\
**Replies:** 14\
**Last updated:** [November 22, 2020, 11:05am UTC](https://discourse.julialang.org/t/fonts-with-consistent-ligature-support-for-julia/43584 "2020-11-22T11:05:18Z")

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I’ve used JetBrains Mono for coding before and I kept using it for Julia, but I’m not happy with some ligatures, especially the dot operator: There was a post mentioning the same issue with Fira Code (Fira Code Font a…

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