# General Usage

**URL:** https://discourse.julialang.org/c/usage/6.md?page=652

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**Page:** 653

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## [Wrong dev & instantiate order in PkgTemplates and Documenter?](https://discourse.julialang.org/t/wrong-dev-instantiate-order-in-pkgtemplates-and-documenter/54062)

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**Author:** [@sijo](https://discourse.julialang.org/u/sijo)\
**Replies:** 0\
**Last updated:** [January 27, 2021, 3:07pm UTC](https://discourse.julialang.org/t/wrong-dev-instantiate-order-in-pkgtemplates-and-documenter/54062 "2021-01-27T15:07:09Z")

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Documenter and PkgTemplates use the following to prepare a docs job: Pkg.develop(PackageSpec(path=pwd())) Pkg.instantiate()' Could it be that this order is wrong? I have a case where it fails with the following error: …

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## [Unicode characters in Plot](https://discourse.julialang.org/t/unicode-characters-in-plot/53997)

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**Author:** [@mcql](https://discourse.julialang.org/u/mcql)\
**Replies:** 8\
**Last updated:** [January 27, 2021, 2:36pm UTC](https://discourse.julialang.org/t/unicode-characters-in-plot/53997 "2021-01-27T14:36:18Z")

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Hello, I’m building a Turing model and I’m using unicode character for the third variable. Plotting the sample I obtain this: How could I correctly render the unicode symbol of the third variable? Thanks

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## [Cannot document @everywhere function](https://discourse.julialang.org/t/cannot-document-everywhere-function/54044)

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**Author:** [@matthiasbe](https://discourse.julialang.org/u/matthiasbe)\
**Replies:** 5\
**Last updated:** [January 27, 2021, 1:43pm UTC](https://discourse.julialang.org/t/cannot-document-everywhere-function/54044 "2021-01-27T13:43:48Z")

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It seems I can not document and put the @everywhere annotation at the same time. The following code """ Prints something """ @everywhere function my\_func() println("hello") end throws the error ERROR: LoadError: ca…

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## [Sundials and SecondOrderODEProblem (OrdinaryDiffEq) not compatible](https://discourse.julialang.org/t/sundials-and-secondorderodeproblem-ordinarydiffeq-not-compatible/53989)

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**Author:** [@magix](https://discourse.julialang.org/u/magix)\
**Replies:** 1\
**Last updated:** [January 27, 2021, 7:05am UTC](https://discourse.julialang.org/t/sundials-and-secondorderodeproblem-ordinarydiffeq-not-compatible/53989 "2021-01-27T07:05:23Z")

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Unfortunately I cannot get a working example of using a SecondOrderODEProblem and any Sundials solver. One workaround is to reformulate the problem as a ODEProblem, but perhaps you know more than I do. This shows the pr…

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## [Is there a way to change font of \`series\_annotations\` in the \`scatter\` plot in Plots?](https://discourse.julialang.org/t/is-there-a-way-to-change-font-of-series-annotations-in-the-scatter-plot-in-plots/54035)

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**Author:** [@paalon](https://discourse.julialang.org/u/paalon)\
**Replies:** 0\
**Last updated:** [January 27, 2021, 6:09am UTC](https://discourse.julialang.org/t/is-there-a-way-to-change-font-of-series-annotations-in-the-scatter-plot-in-plots/54035 "2021-01-27T06:09:25Z")

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Is there a way to change font of series\_annotations in the scatter plot in Plots? using Plots f = font(13, "Noto Sans CJK JP") default( titlefont = f, legendfont = f, guidefont = f, tickfont = f) pyplot(…

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## [Can't do statistics with Dates?](https://discourse.julialang.org/t/cant-do-statistics-with-dates/54020)

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**Author:** [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Replies:** 4\
**Last updated:** [January 27, 2021, 1:35am UTC](https://discourse.julialang.org/t/cant-do-statistics-with-dates/54020 "2021-01-27T01:35:28Z")

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julia\> d = diff(collect(Dates.Date(1980,1,1):Dates.Month(3):Dates.Date(2019,1,1))) 156-element Vector{Day}: 91 days 91 days 92 days 92 days ... julia\> mean(d) ERROR: InexactError: Int64(91.31410256410257)

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## [Interpolation of heatmap with semi-transparent colormaps in Makie](https://discourse.julialang.org/t/interpolation-of-heatmap-with-semi-transparent-colormaps-in-makie/53947)

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**Author:** [@sfmiller940](https://discourse.julialang.org/u/sfmiller940)\
**Replies:** 5\
**Last updated:** [January 26, 2021, 9:58pm UTC](https://discourse.julialang.org/t/interpolation-of-heatmap-with-semi-transparent-colormaps-in-makie/53947 "2021-01-26T21:58:35Z")

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Hello, I’ve been try make heatmaps using colormaps that go from transparent to either white or black. The interpolation works as expected for black but it looks terrible for white. Here’s some sample code with the res…

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## [Sum(log.(p \* C)) is 2 to 4 times slower than in NumPy](https://discourse.julialang.org/t/sum-log-p-c-is-2-to-4-times-slower-than-in-numpy/53960)

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**Author:** [@ForceBru](https://discourse.julialang.org/u/ForceBru)\
**Replies:** 19\
**Last updated:** [January 26, 2021, 11:39pm UTC](https://discourse.julialang.org/t/sum-log-p-c-is-2-to-4-times-slower-than-in-numpy/53960 "2021-01-26T23:39:03Z")

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I’m coming from Python and trying to port my Python code to Julia to gain more performance. I want to compute a lot of log-likelihoods in a loop, so I need a fast function that computes the log-likelihood. The computati…

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## [Version \* does not match other versions](https://discourse.julialang.org/t/version-does-not-match-other-versions/53995)

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**Author:** [@bluesmoon](https://discourse.julialang.org/u/bluesmoon)\
**Replies:** 8\
**Last updated:** [January 26, 2021, 10:47pm UTC](https://discourse.julialang.org/t/version-does-not-match-other-versions/53995 "2021-01-26T22:47:11Z")

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I’m using Julia 1.5.3 Trying to run my tests locally, and I get this error about PyCall version conflicts. My own package has a PyCall version dependency of \* whereas some other package (not one of mine) has a PyCall v…

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## [How to convert all nothings in dataframe to missing?](https://discourse.julialang.org/t/how-to-convert-all-nothings-in-dataframe-to-missing/54004)

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**Author:** [@Joe\_Schnetzler](https://discourse.julialang.org/u/Joe_Schnetzler)\
**Replies:** 14\
**Last updated:** [January 26, 2021, 8:43pm UTC](https://discourse.julialang.org/t/how-to-convert-all-nothings-in-dataframe-to-missing/54004 "2021-01-26T20:43:31Z")

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I have a dataframe with a bunch of nothings mixed between union columns, etc. How can I change all nothings to missings efficiently? Thanks! Best, Joe

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## [Pkg cannot find registered packages](https://discourse.julialang.org/t/pkg-cannot-find-registered-packages/54008)

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**Author:** [@SEA](https://discourse.julialang.org/u/SEA)\
**Replies:** 2\
**Last updated:** [January 26, 2021, 7:58pm UTC](https://discourse.julialang.org/t/pkg-cannot-find-registered-packages/54008 "2021-01-26T19:58:13Z")

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From one minute to another, my installation of Julia cannot add packages anymore. I tried reinstalling Julia but to no avail. How can I fix this? (@v1.5) pkg\> add DiffResults Resolving package versions... ERROR: Unsat…

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## [What happened to LinearAlgebra.full?](https://discourse.julialang.org/t/what-happened-to-linearalgebra-full/53984)

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**Author:** [@gedankenexperiment](https://discourse.julialang.org/u/gedankenexperiment)\
**Replies:** 2\
**Last updated:** [January 26, 2021, 3:36pm UTC](https://discourse.julialang.org/t/what-happened-to-linearalgebra-full/53984 "2021-01-26T15:36:01Z")

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Hi, I’m getting an UndefVarError: full not defined for using OrdinaryDiffEq, RecursiveArrayTools,LinearAlgebra const Mx = full(Tridiagonal(\[1.0 for i in 1:N-1\],\[-2.0 for i in 1:N\],\[1.0 for i in 1:N-1\])) coming from th…

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## [Call OpenCV functions from Julia](https://discourse.julialang.org/t/call-opencv-functions-from-julia/37820)

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**Author:** [@hasanOryx](https://discourse.julialang.org/u/hasanOryx)\
**Replies:** 2\
**Last updated:** [January 26, 2021, 3:21pm UTC](https://discourse.julialang.org/t/call-opencv-functions-from-julia/37820 "2021-01-26T15:21:55Z")

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In this and this the author explaining how to call OpenCV functions from C#. How can I do this from Julia? Here how to make OpenCV C++ project

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## [Opencv help needed for libcbdetect](https://discourse.julialang.org/t/opencv-help-needed-for-libcbdetect/45865)

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**Author:** [@yakir12](https://discourse.julialang.org/u/yakir12)\
**Replies:** 1\
**Last updated:** [January 26, 2021, 3:18pm UTC](https://discourse.julialang.org/t/opencv-help-needed-for-libcbdetect/45865 "2021-01-26T15:18:15Z")

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Hi! I would love to be able to auto-detect checkerboards in images for image-calibration purposes. One way forward is to utilize https://github.com/ftdlyc/libcbdetect (a C++ implementation of libcbdetect which is in Mat…

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## [Confused about intent of using/import (docs)](https://discourse.julialang.org/t/confused-about-intent-of-using-import-docs/53834)

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**Author:** [@MA\_Laforge](https://discourse.julialang.org/u/MA_Laforge)\
**Replies:** 5\
**Last updated:** [January 26, 2021, 3:16pm UTC](https://discourse.julialang.org/t/confused-about-intent-of-using-import-docs/53834 "2021-01-26T15:16:06Z")

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I was reading the (new v1.7) docs on modules (Standalone using and import): Specifically: Possibly the most common way of loading a module is using ModuleName. This loads the code associated with ModuleName, and brin…

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## [Removing characters from String](https://discourse.julialang.org/t/removing-characters-from-string/53962)

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**Author:** [@LinasBa](https://discourse.julialang.org/u/LinasBa)\
**Replies:** 15\
**Last updated:** [January 26, 2021, 3:04pm UTC](https://discourse.julialang.org/t/removing-characters-from-string/53962 "2021-01-26T15:04:18Z")

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Hello, I would like to remove some characters from String, but that seems to be really complicated in Julia :frowning: Example: str = "ž1ž1" r = r"1" idx = eachmatch(r, str) .|\> o -\> o.offset result = String(deleteat!…

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## [Using callback functions via CallbackSet](https://discourse.julialang.org/t/using-callback-functions-via-callbackset/53985)

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**Author:** [@JuliaCantisan](https://discourse.julialang.org/u/JuliaCantisan)\
**Replies:** 1\
**Last updated:** [January 26, 2021, 2:48pm UTC](https://discourse.julialang.org/t/using-callback-functions-via-callbackset/53985 "2021-01-26T14:48:39Z")

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Hi everyone, I’m trying to add two DiscreteCallbacks to my integrator using CallbackSet. Each of them seem to work when the other one is not present, but the first one does not work when the second one is present. This …

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## [Graphing a large, tiled graph with PlotlyJS](https://discourse.julialang.org/t/graphing-a-large-tiled-graph-with-plotlyjs/53979)

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**Author:** [@Smack](https://discourse.julialang.org/u/Smack)\
**Replies:** 5\
**Last updated:** [January 26, 2021, 2:30pm UTC](https://discourse.julialang.org/t/graphing-a-large-tiled-graph-with-plotlyjs/53979 "2021-01-26T14:30:13Z")

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Hi, I am trying to plot multiple scatter plots and save them in a file (svg/pdf) After creating the plots and saving them in a variable, I find the only way I can tile them is with the splatter operator: \[plots\_array……

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## [Import CSV where the rows are separated by brackets](https://discourse.julialang.org/t/import-csv-where-the-rows-are-separated-by-brackets/53971)

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**Author:** [@Okarin99](https://discourse.julialang.org/u/Okarin99)\
**Replies:** 1\
**Last updated:** [January 26, 2021, 1:50pm UTC](https://discourse.julialang.org/t/import-csv-where-the-rows-are-separated-by-brackets/53971 "2021-01-26T13:50:26Z")

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Hey, is there a simple way to import a csv file in which each row is separated by brackets? My file looks like this: \[Energie in MeV, y\_na, u\_(y\_na)\] \[0.09760250284217108, 0.3514244536139464, 0.013170188213585452\] \[0.…

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## [Is there a way to keep and manage an parallel/asyncronous task queue?](https://discourse.julialang.org/t/is-there-a-way-to-keep-and-manage-an-parallel-asyncronous-task-queue/53942)

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**Author:** [@apoor](https://discourse.julialang.org/u/apoor)\
**Replies:** 2\
**Last updated:** [January 26, 2021, 10:06am UTC](https://discourse.julialang.org/t/is-there-a-way-to-keep-and-manage-an-parallel-asyncronous-task-queue/53942 "2021-01-26T10:06:18Z")

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I’m playing around with writing a simple load tester (sort of like locust). I want to maintain a task-queue/pool of workers making requests to my web app. When the program starts, the worker pool will fill up. As some r…

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## [Performance issue with QRCompactWYQ](https://discourse.julialang.org/t/performance-issue-with-qrcompactwyq/53732)

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**Author:** [@theogf](https://discourse.julialang.org/u/theogf)\
**Replies:** 1\
**Last updated:** [January 26, 2021, 8:46am UTC](https://discourse.julialang.org/t/performance-issue-with-qrcompactwyq/53732 "2021-01-26T08:46:19Z")

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Hey, since it’s not a bug specifically but a performance issue I post it here instead on Github. In the attempt of generating random positive definite matrices I realized there was a huge performance issue with the QRCo…

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## [5 \< x != y \< 5](https://discourse.julialang.org/t/5-x-y-5/53844)

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**Author:** [@JimFromAZ](https://discourse.julialang.org/u/JimFromAZ)\
**Replies:** 18\
**Last updated:** [January 26, 2021, 3:37am UTC](https://discourse.julialang.org/t/5-x-y-5/53844 "2021-01-26T03:37:42Z")

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Hi All, I am reviewing The Fast Track to julia. In the Basics section Chaining is mentioned. Three lines of code are: x = y = z = 1 # right-to-left 0 \< x \< 3 # true 5 \< x != y \< 5 # false It’s the last line that I …

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## [New Dataframe Column from a View from Another DataFrames](https://discourse.julialang.org/t/new-dataframe-column-from-a-view-from-another-dataframes/53945)

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**Author:** [@TheCedarPrince](https://discourse.julialang.org/u/TheCedarPrince)\
**Replies:** 1\
**Last updated:** [January 26, 2021, 1:29am UTC](https://discourse.julialang.org/t/new-dataframe-column-from-a-view-from-another-dataframes/53945 "2021-01-26T01:29:24Z")

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Hi all, I have a dataframe and a column view of a another dataframe B like this: A = DataFrame(\[1 3 5; 1 3 5; 2 4 6; 2 4 6;\]) C = @view B\[col\] A looks like this: 4×3 DataFrame Row │ x1 x2 x3 │ Int64 In…

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## [Pkg.update() taking ~10min, how do I debug?](https://discourse.julialang.org/t/pkg-update-taking-10min-how-do-i-debug/53926)

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**Author:** [@marius311](https://discourse.julialang.org/u/marius311)\
**Replies:** 4\
**Last updated:** [January 25, 2021, 9:19pm UTC](https://discourse.julialang.org/t/pkg-update-taking-10min-how-do-i-debug/53926 "2021-01-25T21:19:04Z")

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On this one particular system, Pkg.update()s are unbearably slow, it spends 5-10 minutes displaying Updating registry at ~/.julia/registries/General. This system has a notorioulsy slow network filesystem, granted not thi…

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## [Hashing for big structs is slow - any alternative?](https://discourse.julialang.org/t/hashing-for-big-structs-is-slow-any-alternative/53815)

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**Author:** [@bsuwal](https://discourse.julialang.org/u/bsuwal)\
**Replies:** 12\
**Last updated:** [January 25, 2021, 7:36pm UTC](https://discourse.julialang.org/t/hashing-for-big-structs-is-slow-any-alternative/53815 "2021-01-25T19:36:06Z")

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I have three structs, one mutable and two immutable, defined as: mutable struct Node label::NodeEdge comp::Vector{UInt8} comp\_weights::Vector{UInt8} cc::UInt8 fps::Vector{F…

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## [How to Pre-check Checkboxes Using Interact.jl?](https://discourse.julialang.org/t/how-to-pre-check-checkboxes-using-interact-jl/53802)

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**Author:** [@TheCedarPrince](https://discourse.julialang.org/u/TheCedarPrince)\
**Replies:** 2\
**Last updated:** [January 25, 2021, 6:47pm UTC](https://discourse.julialang.org/t/how-to-pre-check-checkboxes-using-interact-jl/53802 "2021-01-25T18:47:38Z")

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How do I use Interact.jl to present a list of checkboxes with some of the boxes already checked off? Tried following the documentation and couldn’t figure out how to set specific checkboxes to true (i.e. checked off). W…

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## [Inducing a Task to finish](https://discourse.julialang.org/t/inducing-a-task-to-finish/53923)

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**Author:** [@Josiah\_Slack](https://discourse.julialang.org/u/Josiah_Slack)\
**Replies:** 0\
**Last updated:** [January 25, 2021, 6:37pm UTC](https://discourse.julialang.org/t/inducing-a-task-to-finish/53923 "2021-01-25T18:37:03Z")

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I’m afraid there a lot of moving parts in this question. I’ve created a Task that reads from a Channel and writes to a WebSocket. I’d like to be able to wait() for the Task to finish, and I’d like the Task to finish when…

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## [How to write scripts with quick startup time (PackageCompiler.jl?)](https://discourse.julialang.org/t/how-to-write-scripts-with-quick-startup-time-packagecompiler-jl/53900)

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**Author:** [@greatpet](https://discourse.julialang.org/u/greatpet)\
**Replies:** 2\
**Last updated:** [January 25, 2021, 6:05pm UTC](https://discourse.julialang.org/t/how-to-write-scripts-with-quick-startup-time-packagecompiler-jl/53900 "2021-01-25T18:05:26Z")

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I’d like to use Julia to write some scripts for quick tasks that could be otherwise done with Bash, sed, etc. Is there a good way to precompile the script to make it start quickly? Is PackageCompiler.jl a good option, an…

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## [Weave texw to tex/pdf](https://discourse.julialang.org/t/weave-texw-to-tex-pdf/43218)

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**Author:** [@krcools](https://discourse.julialang.org/u/krcools)\
**Replies:** 1\
**Last updated:** [January 25, 2021, 4:43pm UTC](https://discourse.julialang.org/t/weave-texw-to-tex-pdf/43218 "2021-01-25T16:43:00Z")

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Do recent versions of Weave.jl have support for weaving Julia code and output in the texw format? I have found an example file in the source but no reference in the documentation. I could not get this to work.

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## [Revise and structure-local functions](https://discourse.julialang.org/t/revise-and-structure-local-functions/53914)

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**Author:** [@fieker](https://discourse.julialang.org/u/fieker)\
**Replies:** 3\
**Last updated:** [January 25, 2021, 3:33pm UTC](https://discourse.julialang.org/t/revise-and-structure-local-functions/53914 "2021-01-25T15:33:11Z")

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Consider the following (pointless) module: module ReviseCrash struct Blah a::Int function Blah() return new(), x-\>f1() end function f1() return 3 end end function f2() return 1 end end The cons…

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