# New to Julia

**URL:** https://discourse.julialang.org/c/first-steps/8.md?page=52

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**Page:** 53

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## [Changes of A.jl are not understood from B.jl that includes A.jl](https://discourse.julialang.org/t/changes-of-a-jl-are-not-understood-from-b-jl-that-includes-a-jl/110498)

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**Author:** [@DoctorDro](https://discourse.julialang.org/u/DoctorDro)\
**Replies:** 96\
**Last updated:** [March 9, 2024, 10:43pm UTC](https://discourse.julialang.org/t/changes-of-a-jl-are-not-understood-from-b-jl-that-includes-a-jl/110498 "2024-03-09T22:43:19Z")

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Dear all, I am new, so many things could be different than Matlab or any other C,C++,Fortran language here. But I experienced a weird behaviour. My script B.jl starts by including a function found in another script A.jl…

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## [Mcedit syntax file](https://discourse.julialang.org/t/mcedit-syntax-file/111082)

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**Author:** [@BloodFeastMan](https://discourse.julialang.org/u/BloodFeastMan)\
**Replies:** 4\
**Last updated:** [March 8, 2024, 3:22pm UTC](https://discourse.julialang.org/t/mcedit-syntax-file/111082 "2024-03-08T15:22:29Z")

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I wonder if anyone has already made a syntax file for Mcedit?

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## [Couldn't use TransformedTargetModel() function in MLJ](https://discourse.julialang.org/t/couldnt-use-transformedtargetmodel-function-in-mlj/111347)

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**Author:** [@Realyyc](https://discourse.julialang.org/u/Realyyc)\
**Replies:** 0\
**Last updated:** [March 8, 2024, 11:26am UTC](https://discourse.julialang.org/t/couldnt-use-transformedtargetmodel-function-in-mlj/111347 "2024-03-08T11:26:10Z")

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I’ve downloaded MLJ pkg, but : using MLJ TransformedTargetModel() UndefVarError: \`TransformedTargetModel\` not defined Stacktrace: \[1\] top-level scope @ In\[22\]:10 I don’t know if the function is actually not in t…

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## [Understanding how KNearestSearch works](https://discourse.julialang.org/t/understanding-how-knearestsearch-works/111294)

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**Author:** [@xiaoming](https://discourse.julialang.org/u/xiaoming)\
**Replies:** 5\
**Last updated:** [March 7, 2024, 3:15pm UTC](https://discourse.julialang.org/t/understanding-how-knearestsearch-works/111294 "2024-03-07T15:15:55Z")

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I have a surface in three-dimensional space composed of triangles generated by Meshes.jl. Given a point in space, the function ‘search’ in Meshes.jl can find the closest triangle to this point. I want to know how this di…

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## [Stop threads after a certain condition is true](https://discourse.julialang.org/t/stop-threads-after-a-certain-condition-is-true/111062)

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**Author:** [@nickk2002](https://discourse.julialang.org/u/nickk2002)\
**Replies:** 19\
**Last updated:** [March 6, 2024, 9:30pm UTC](https://discourse.julialang.org/t/stop-threads-after-a-certain-condition-is-true/111062 "2024-03-06T21:30:52Z")

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I want to to run n threads in parallel and if one of the threads reaches cost 0 I would like to stop all the others. How can I do this? best\_expression, best\_program, program\_cost = nothing, start\_program, Inf64 lk …

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## [Fail to precompile Plots](https://discourse.julialang.org/t/fail-to-precompile-plots/111194)

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**Author:** [@ShenXin](https://discourse.julialang.org/u/ShenXin)\
**Replies:** 9\
**Last updated:** [March 6, 2024, 4:44pm UTC](https://discourse.julialang.org/t/fail-to-precompile-plots/111194 "2024-03-06T16:44:13Z")

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Hi, I’m new to Julia. The follwing question fails me to use Plots.jl. I completely have no idea what’s the error. Part of the error is listed below. ERROR: Failed to precompile Plots \[91a5bcdd-55d7-5caf-9e0b-520d859cae…

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## [No heatmap interpolation in CairoMakie?](https://discourse.julialang.org/t/no-heatmap-interpolation-in-cairomakie/79662)

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**Author:** [@poopsilon](https://discourse.julialang.org/u/poopsilon)\
**Replies:** 3\
**Last updated:** [March 6, 2024, 2:49pm UTC](https://discourse.julialang.org/t/no-heatmap-interpolation-in-cairomakie/79662 "2024-03-06T14:49:26Z")

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I am trying to plot a heatmap with color interpolation, but I can’t seem to do it. I tried do it using the example from the Makie website using CairoMakie xs = range(0, 10, length = 25) ys = range(0, 15, length = 25) z…

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## [Given up installing any plotting packages](https://discourse.julialang.org/t/given-up-installing-any-plotting-packages/110272)

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**Author:** [@neophytedave](https://discourse.julialang.org/u/neophytedave)\
**Replies:** 35\
**Last updated:** [March 6, 2024, 5:50am UTC](https://discourse.julialang.org/t/given-up-installing-any-plotting-packages/110272 "2024-03-06T05:50:06Z")

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I have given up attempting to install any plotting packages, under any version of Julia. I have tried a variety, including Plots, Makie, GLMakie, Gaston, Unicode, etc. etc. I always get the same error: “Access Denied”.…

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## [Operation does not match](https://discourse.julialang.org/t/operation-does-not-match/111210)

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**Author:** [@martin\_sanchez](https://discourse.julialang.org/u/martin_sanchez)\
**Replies:** 2\
**Last updated:** [March 5, 2024, 7:30pm UTC](https://discourse.julialang.org/t/operation-does-not-match/111210 "2024-03-05T19:30:45Z")

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If I make A=\[2/3 1/3; -1/3 1/3\]. v=\[1,-4\], and make A\*v I get -0.6666666666666666 -1.6666666666666665 Which is fine except that i I make -5/3 I get -1.6666666666666667. Is this just rounding error being different fo…

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## [Cannot use PlotlyJS](https://discourse.julialang.org/t/cannot-use-plotlyjs/105057)

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**Author:** [@Guillaume](https://discourse.julialang.org/u/Guillaume)\
**Replies:** 9\
**Last updated:** [March 5, 2024, 5:54pm UTC](https://discourse.julialang.org/t/cannot-use-plotlyjs/105057 "2024-03-05T17:54:41Z")

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Hi, I have a fresh Julia install on a new computer (windows 11). I can’t install PlotlyJS. import Pkg; Pkg.add("PlotlyJS") using PlotlyJS After the using command, the repl gets stuck indefinitely. Interrupting it retur…

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## [PlotlyJS causes errors, can't figure out how to use PlotlyLight - how to use Plotly from Julia?](https://discourse.julialang.org/t/plotlyjs-causes-errors-cant-figure-out-how-to-use-plotlylight-how-to-use-plotly-from-julia/108853)

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**Author:** [@jojob68](https://discourse.julialang.org/u/jojob68)\
**Replies:** 37\
**Last updated:** [March 5, 2024, 5:57pm UTC](https://discourse.julialang.org/t/plotlyjs-causes-errors-cant-figure-out-how-to-use-plotlylight-how-to-use-plotly-from-julia/108853 "2024-03-05T17:57:51Z")

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First post, new to Julia coming from Matlab, so please bear with me, I seem to be struggling with the most basic stuff. After lots of reading, it seems PlotlyJS is the best plotting package for my use case: interactive …

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## [Graph doesn't display in Julia Notebook (VSCode) using PyPlot](https://discourse.julialang.org/t/graph-doesnt-display-in-julia-notebook-vscode-using-pyplot/111150)

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**Author:** [@Matheus](https://discourse.julialang.org/u/Matheus)\
**Replies:** 5\
**Last updated:** [March 5, 2024, 5:48pm UTC](https://discourse.julialang.org/t/graph-doesnt-display-in-julia-notebook-vscode-using-pyplot/111150 "2024-03-05T17:48:27Z")

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I’m having trouble in making the following code work using PyPlot plot(rand(10)) The output I get is: 1-element Vector{PyCall.PyObject}: PyObject \<matplotlib.lines.Line2D object at 0x000001B97E679030\> If I use the …

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## [Help with UpROOT in Julia](https://discourse.julialang.org/t/help-with-uproot-in-julia/111149)

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**Author:** [@rushabhgala](https://discourse.julialang.org/u/rushabhgala)\
**Replies:** 7\
**Last updated:** [March 5, 2024, 5:23pm UTC](https://discourse.julialang.org/t/help-with-uproot-in-julia/111149 "2024-03-05T17:23:38Z")

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This is my code using UpROOT f = TFile("test.root") println(keys(f)) which gives the output \["raw;1", "mul;1", "lar;1", "mul\_lar;1"\] There are about a 100 histograms in raw, mul, lar, mul\_lar of type TH1F How do I p…

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## [Access iRods or Yoda directly from julia code](https://discourse.julialang.org/t/access-irods-or-yoda-directly-from-julia-code/111196)

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**Author:** [@Fenrir\_Sivar](https://discourse.julialang.org/u/Fenrir_Sivar)\
**Replies:** 0\
**Last updated:** [March 5, 2024, 2:19pm UTC](https://discourse.julialang.org/t/access-irods-or-yoda-directly-from-julia-code/111196 "2024-03-05T14:19:19Z")

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hi anyone, My institute hosts a yoda instance where all our data resides. There are a ton of python packages to work with Yoda and iRods (the underlying tech), but I haven’t come across any for Julia. Anyone with experi…

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## [Need to reactivate following errors](https://discourse.julialang.org/t/need-to-reactivate-following-errors/111190)

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**Author:** [@HAL9000](https://discourse.julialang.org/u/HAL9000)\
**Replies:** 0\
**Last updated:** [March 5, 2024, 12:06pm UTC](https://discourse.julialang.org/t/need-to-reactivate-following-errors/111190 "2024-03-05T12:06:25Z")

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Hi I am using VSCode GameZero and find that quite often I have to re-activate directory from REPL after a run error. I know I have to reactivate because I get a gamezero error when it tries to load fonts. Am I doing s…

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## [Different result as Turing.jl tutorial](https://discourse.julialang.org/t/different-result-as-turing-jl-tutorial/111142)

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**Author:** [@Zhijian](https://discourse.julialang.org/u/Zhijian)\
**Replies:** 1\
**Last updated:** [March 4, 2024, 6:23pm UTC](https://discourse.julialang.org/t/different-result-as-turing-jl-tutorial/111142 "2024-03-04T18:23:49Z")

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Hi guys, Recently I was learning parameter estimation, and was following the tutorial of Turing.jl: https://turing.ml/dev/tutorials/10-bayesian-differential-equations/ However, in the first case of The Lotka-Volterra …

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## [My first Agents.jl project - Toy model of rental market](https://discourse.julialang.org/t/my-first-agents-jl-project-toy-model-of-rental-market/111127)

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**Author:** [@Piotr\_Zakrzewski](https://discourse.julialang.org/u/Piotr_Zakrzewski)\
**Replies:** 0\
**Last updated:** [March 4, 2024, 12:21pm UTC](https://discourse.julialang.org/t/my-first-agents-jl-project-toy-model-of-rental-market/111127 "2024-03-04T12:21:07Z")

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I have long been interested in agent based simulations so I played around with Agents.jl to make a toy model of rental market. I published it here: GitHub - PiotrZakrzewski/real-estate-sim: Julia Agent Simulation of Rea…

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## [Converting 3D DelaunayTriangulation into Mesh](https://discourse.julialang.org/t/converting-3d-delaunaytriangulation-into-mesh/111073)

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**Author:** [@AliC](https://discourse.julialang.org/u/AliC)\
**Replies:** 1\
**Last updated:** [March 3, 2024, 7:42pm UTC](https://discourse.julialang.org/t/converting-3d-delaunaytriangulation-into-mesh/111073 "2024-03-03T19:42:47Z")

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I have a DelaunayTriangulation.Triangulation that contains 3D points. I want to plot it using Makie, but I’ve only seen that 2D triangulations can be plotted directly using triplot. If I try to triplot the 3D triangulat…

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## [Poor Mesh Plot from Makie - How to fix it?](https://discourse.julialang.org/t/poor-mesh-plot-from-makie-how-to-fix-it/111064)

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**Author:** [@Midez](https://discourse.julialang.org/u/Midez)\
**Replies:** 9\
**Last updated:** [March 3, 2024, 7:10pm UTC](https://discourse.julialang.org/t/poor-mesh-plot-from-makie-how-to-fix-it/111064 "2024-03-03T19:10:32Z")

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Minimal example with a dummy mesh using Makie, GLMakie, FileIO msh = load("~/TestMesh.stl") fig = Figure(resolution = (1920,1080)) axe = Axis3(fig\[1, 1\]) mesh!(msh, transparency = false, overdraw = false, shading …

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## [Test expression for instance of variable](https://discourse.julialang.org/t/test-expression-for-instance-of-variable/110740)

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**Author:** [@brombo](https://discourse.julialang.org/u/brombo)\
**Replies:** 1\
**Last updated:** [March 3, 2024, 6:37am UTC](https://discourse.julialang.org/t/test-expression-for-instance-of-variable/110740 "2024-03-03T06:37:31Z")

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Is there a way of testing a symbolic expression to see if it contains a given variable other than seeing if the derivative is zero. For example test (r\*sin(th))^2 to see if it contains th. Is there a way of looking at …

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## [Events in progress and non exclusive active events](https://discourse.julialang.org/t/events-in-progress-and-non-exclusive-active-events/111077)

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**Author:** [@JBH\_84](https://discourse.julialang.org/u/JBH_84)\
**Replies:** 0\
**Last updated:** [March 3, 2024, 12:39am UTC](https://discourse.julialang.org/t/events-in-progress-and-non-exclusive-active-events/111077 "2024-03-03T00:39:32Z")

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Hello I am trying to figure out an efficient way to set up an “events in progress” problem in dataframes.jl. I have two tables. the first is a performance log that tracks what units are doing by hour. The second is an e…

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## [Vcat for Vector{Any}](https://discourse.julialang.org/t/vcat-for-vector-any/111065)

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**Author:** [@Enlil50](https://discourse.julialang.org/u/Enlil50)\
**Replies:** 1\
**Last updated:** [March 2, 2024, 3:57pm UTC](https://discourse.julialang.org/t/vcat-for-vector-any/111065 "2024-03-02T15:57:39Z")

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I have this part of code: #can't be change len::Int64 = 4 a = rand(Float64, len) a\_1 = Int64.(floor.(@view a\[1:2:len\])) a\_2 = @view a\[2:2:len\] display(a\_1) #can be changed b = vcat\[Vector{Any}(a\_1), a\_2\] It throws th…

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## [Some errors from PlasmoPlots](https://discourse.julialang.org/t/some-errors-from-plasmoplots/111047)

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**Author:** [@lichen2023905](https://discourse.julialang.org/u/lichen2023905)\
**Replies:** 2\
**Last updated:** [March 2, 2024, 8:43am UTC](https://discourse.julialang.org/t/some-errors-from-plasmoplots/111047 "2024-03-02T08:43:21Z")

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Some functions such as matrix\_layout, layoutplot will show undefined when called UndefVarError: matrix\_layout not defined UndefVarError: layoutplot not defined

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## [Using Gridap for a 1D heat transfer equation](https://discourse.julialang.org/t/using-gridap-for-a-1d-heat-transfer-equation/111010)

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**Author:** [@Mishal](https://discourse.julialang.org/u/Mishal)\
**Replies:** 1\
**Last updated:** [March 1, 2024, 1:29pm UTC](https://discourse.julialang.org/t/using-gridap-for-a-1d-heat-transfer-equation/111010 "2024-03-01T13:29:22Z")

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Hi Guys So I have just started my journey learning Julia and really keen on Starting to use Gridap. I am still brushing up my knowledge on various topics. Please refer to the below code, this code uses the differential…

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## [Trouble with function calls](https://discourse.julialang.org/t/trouble-with-function-calls/110940)

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**Author:** [@andreasvarga](https://discourse.julialang.org/u/andreasvarga)\
**Replies:** 5\
**Last updated:** [March 1, 2024, 11:34am UTC](https://discourse.julialang.org/t/trouble-with-function-calls/110940 "2024-03-01T11:34:57Z")

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The following commands produce a side effect which I can not explain: julia\> using LinearAlgebra julia\> A = 2\*Matrix(I(2)) 2×2 Matrix{Int64}: 2 0 0 2 julia\> B = 3\*Matrix(I(2)) 2×2 Matrix{Int64}: 3 0 0 3 julia\>…

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## [Difference between \[1, 2, 3, 4\] / \[1, 2, 3, 4\] vs \[1, 2, 3, 4\] ./ \[1, 2, 3, 4\]](https://discourse.julialang.org/t/difference-between-1-2-3-4-1-2-3-4-vs-1-2-3-4-1-2-3-4/110999)

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**Author:** [@Sahil\_Khan](https://discourse.julialang.org/u/Sahil_Khan)\
**Replies:** 9\
**Last updated:** [March 1, 2024, 10:58am UTC](https://discourse.julialang.org/t/difference-between-1-2-3-4-1-2-3-4-vs-1-2-3-4-1-2-3-4/110999 "2024-03-01T10:58:50Z")

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Hello, Does someone know what exactly happens in background when we do \[1, 2, 3, 4\] / \[1, 2, 3, 4\]. For \[1, 2, 3, 4\] ./ \[1, 2, 3, 4\] is clear that it’s doing element-wise division as shown below. But what about \[1, 2…

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## [How to make a air mouse using webcam using julia](https://discourse.julialang.org/t/how-to-make-a-air-mouse-using-webcam-using-julia/110993)

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**Author:** [@Sujan\_Das](https://discourse.julialang.org/u/Sujan_Das)\
**Replies:** 0\
**Last updated:** [March 1, 2024, 4:34am UTC](https://discourse.julialang.org/t/how-to-make-a-air-mouse-using-webcam-using-julia/110993 "2024-03-01T04:34:21Z")

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Please help me out with the required packages and if possible a guide to create my project

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## [Startup.jl ...Exit.jl](https://discourse.julialang.org/t/startup-jl-exit-jl/110908)

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**Author:** [@gitboy16](https://discourse.julialang.org/u/gitboy16)\
**Replies:** 4\
**Last updated:** [February 29, 2024, 2:45pm UTC](https://discourse.julialang.org/t/startup-jl-exit-jl/110908 "2024-02-29T14:45:09Z")

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Hi, We have the option run automatically things when Julia starts using the Startup.jl file. Is there something similar when you exist Julia? If it does not exist, is it a reasonable feature to ask for? Or is there a…

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## [Help using GraphMakie to emulate GraphRecipes plot using edge\_width and number of edges](https://discourse.julialang.org/t/help-using-graphmakie-to-emulate-graphrecipes-plot-using-edge-width-and-number-of-edges/109629)

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**Author:** [@keynescoefen](https://discourse.julialang.org/u/keynescoefen)\
**Replies:** 1\
**Last updated:** [February 29, 2024, 12:20am UTC](https://discourse.julialang.org/t/help-using-graphmakie-to-emulate-graphrecipes-plot-using-edge-width-and-number-of-edges/109629 "2024-02-29T00:20:21Z")

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Hello! I started using GraphMakie mostly due to this issue here: Dots in the middle of nodes · Issue #154 · JuliaPlots/GraphRecipes.jl · GitHub Dots in the middle of labels, which afaik, persists to today. I therefore …

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## [Stripping or replacing substrings into a vector of strings](https://discourse.julialang.org/t/stripping-or-replacing-substrings-into-a-vector-of-strings/110851)

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**Author:** [@mocalvao](https://discourse.julialang.org/u/mocalvao)\
**Replies:** 9\
**Last updated:** [February 28, 2024, 5:40pm UTC](https://discourse.julialang.org/t/stripping-or-replacing-substrings-into-a-vector-of-strings/110851 "2024-02-28T17:40:27Z")

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Hi there, I have a dataframe df\_ln, whose names are: julia\> names(df\_ln) 11-element Vector{String}: "Aluno" "DRE" "Questionário: Teste 1 (T1) (Real)" "Questionário: Primeira Prova (P1) (Real)" "Questionário: Teste…

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