# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1796

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

**Page:** 1797

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## [Streaming gziped file to FASTQ.Reader - where to add method?](https://discourse.julialang.org/t/streaming-gziped-file-to-fastq-reader-where-to-add-method/36266)

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**Author:** [@kevbonham](https://discourse.julialang.org/u/kevbonham)\
**Replies:** 2\
**Last updated:** [March 20, 2020, 3:21pm UTC](https://discourse.julialang.org/t/streaming-gziped-file-to-fastq-reader-where-to-add-method/36266 "2020-03-20T15:21:15Z")

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FASTQ is a file format used for DNA sequencing, and we have a handy reader in the FASTX package. using FASTX testfile = "some/path.fastq" for record in FASTQ.Reader(open(testfile)) seq = FASTQ.sequence(record) …

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## [How to plot an annotation with datetime X](https://discourse.julialang.org/t/how-to-plot-an-annotation-with-datetime-x/36143)

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**Author:** [@Ronneesley](https://discourse.julialang.org/u/Ronneesley)\
**Replies:** 1\
**Last updated:** [March 20, 2020, 3:11pm UTC](https://discourse.julialang.org/t/how-to-plot-an-annotation-with-datetime-x/36143 "2020-03-20T15:11:51Z")

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Hello, Using Plots module I have a problem positioning annotations as you can see: using Plots x = 1 plot(\[x\], \[1\], legend=false) annotate!(\[x\], \[2\], Plots.text("Here", 16, :red, :center)) This works perfectly, pos…

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## [How to impose ordered constraints to model variables](https://discourse.julialang.org/t/how-to-impose-ordered-constraints-to-model-variables/36264)

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**Author:** [@takuizum](https://discourse.julialang.org/u/takuizum)\
**Replies:** 0\
**Last updated:** [March 20, 2020, 2:39pm UTC](https://discourse.julialang.org/t/how-to-impose-ordered-constraints-to-model-variables/36264 "2020-03-20T14:39:56Z")

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Hi, everyone. Lately, I have been learning Bayesian inference with Julia and Turing and trying to implement IRT(Item response model; logistic regression with latent variables). Today, I ask a question related to ordere…

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## [Writing simple weighted digraphs](https://discourse.julialang.org/t/writing-simple-weighted-digraphs/36263)

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**Author:** [@eaubanel](https://discourse.julialang.org/u/eaubanel)\
**Replies:** 0\
**Last updated:** [March 20, 2020, 2:37pm UTC](https://discourse.julialang.org/t/writing-simple-weighted-digraphs/36263 "2020-03-20T14:37:57Z")

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I’m using the LightGraphs package and I’m trying to write a simple weighted digraph to a file: julia\> g {32768, 467633} directed simple Int64 graph with Float64 weights julia\> savegraph("testwt.lg",g) 1 julia\> gl=loadgr…

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## [Cannot update Julia packages](https://discourse.julialang.org/t/cannot-update-julia-packages/36240)

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**Author:** [@Yifan\_Liu](https://discourse.julialang.org/u/Yifan_Liu)\
**Replies:** 4\
**Last updated:** [March 20, 2020, 1:59pm UTC](https://discourse.julialang.org/t/cannot-update-julia-packages/36240 "2020-03-20T13:59:38Z")

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I am using Julia 1.2 on Fedora 31. When I tried to update Julia packages today, I got this error message: signal (11): Segmentation fault in expression starting at none:0 unknown function (ip: 0x7f2b3abdb9f7) http\_pars…

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## [Question regarding Pkg environments](https://discourse.julialang.org/t/question-regarding-pkg-environments/36249)

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**Author:** [@skarppinen](https://discourse.julialang.org/u/skarppinen)\
**Replies:** 6\
**Last updated:** [March 20, 2020, 12:37pm UTC](https://discourse.julialang.org/t/question-regarding-pkg-environments/36249 "2020-03-20T12:37:07Z")

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Hello. I am confused about using Pkg environments. Suppose I create a new directory on my system called “NewProject”. Then I change my directory to this new folder, launch Julia, hit \] to launch Pkg and type activate …

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## [Use of constant types](https://discourse.julialang.org/t/use-of-constant-types/36251)

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**Author:** [@erlebach](https://discourse.julialang.org/u/erlebach)\
**Replies:** 2\
**Last updated:** [March 20, 2020, 12:18pm UTC](https://discourse.julialang.org/t/use-of-constant-types/36251 "2020-03-20T12:18:10Z")

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I am struggling with the issue of changing the type of a global variable. I keep a set of functions I am working on in a file “global\_functions.jl”, which I include in my main program. I then give it a shortcut in the g…

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## [In-place/fused broadcasting](https://discourse.julialang.org/t/in-place-fused-broadcasting/21067)

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**Author:** [@robsmith11](https://discourse.julialang.org/u/robsmith11)\
**Replies:** 10\
**Last updated:** [February 22, 2019, 2:32pm UTC](https://discourse.julialang.org/t/in-place-fused-broadcasting/21067 "2019-02-22T14:32:51Z")

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I often write something like exp.(rand(10^6)) which is convienent, but inefficient as it allocates 2 arrays. What I really want is x = rand(10^6) map!(exp, x, x) Is there a single-line/idiomatic way to write this op…

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## [Make is running forever](https://discourse.julialang.org/t/make-is-running-forever/35663)

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**Author:** [@the\_daemon\_lord](https://discourse.julialang.org/u/the_daemon_lord)\
**Replies:** 2\
**Last updated:** [March 20, 2020, 10:04am UTC](https://discourse.julialang.org/t/make-is-running-forever/35663 "2020-03-20T10:04:00Z")

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Greetings! I wanted to build Julia from scratch so I cloned the Julia repo today and ran make. It has been Generating precompile statements... for 10+ hours now. Is it normal for it to take so long? This is the third t…

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## [Defining traits on functions using macros](https://discourse.julialang.org/t/defining-traits-on-functions-using-macros/36210)

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**Author:** [@MaximeBouton](https://discourse.julialang.org/u/MaximeBouton)\
**Replies:** 10\
**Last updated:** [March 20, 2020, 9:19am UTC](https://discourse.julialang.org/t/defining-traits-on-functions-using-macros/36210 "2020-03-20T09:19:28Z")

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Hello, I am trying to use traits on functions and I would like to define the trait automatically based on existing methods. I have several traits like EntityFeature and FrameFeature and a function featuretype(::typeof(…

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## [Losing grid when zooming in plotlyjs in Juno](https://discourse.julialang.org/t/losing-grid-when-zooming-in-plotlyjs-in-juno/36226)

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**Author:** [@rveltz](https://discourse.julialang.org/u/rveltz)\
**Replies:** 0\
**Last updated:** [March 19, 2020, 8:54pm UTC](https://discourse.julialang.org/t/losing-grid-when-zooming-in-plotlyjs-in-juno/36226 "2020-03-19T20:54:00Z")

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Hi, When I use Plotlyjs.jl through Plots,jl in Juno (this is by the way a fantastic interactive tool), I lose the backward grid when zooming (or at least it does not adapt to the new zooming window). This is inconvenien…

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## [ANN: julia-build, jlenv, jlenv-plugins and jlenv-cookbook](https://discourse.julialang.org/t/ann-julia-build-jlenv-jlenv-plugins-and-jlenv-cookbook/30528)

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**Author:** [@taqtiqa-mark](https://discourse.julialang.org/u/taqtiqa-mark)\
**Replies:** 15\
**Last updated:** [March 20, 2020, 3:15am UTC](https://discourse.julialang.org/t/ann-julia-build-jlenv-jlenv-plugins-and-jlenv-cookbook/30528 "2020-03-20T03:15:51Z")

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Ann: jlenv & plugins - Robust Julia version management This is a 1.0.0 release of the Julia port of the rbnev/pyenv tools and plugins. As well as some projects supporting Julia configuration and version management. NOT…

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## [Simple tool for train test split](https://discourse.julialang.org/t/simple-tool-for-train-test-split/473)

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**Author:** [@klezmen](https://discourse.julialang.org/u/klezmen)\
**Replies:** 12\
**Last updated:** [March 20, 2020, 1:09am UTC](https://discourse.julialang.org/t/simple-tool-for-train-test-split/473 "2020-03-20T01:09:54Z")

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Does anyone know a tool that enables me to split a dataframe in to a training set and a test set?

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## [Error in using PyPlot in Julia](https://discourse.julialang.org/t/error-in-using-pyplot-in-julia/36234)

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**Author:** [@fksayaci](https://discourse.julialang.org/u/fksayaci)\
**Replies:** 1\
**Last updated:** [March 20, 2020, 12:44am UTC](https://discourse.julialang.org/t/error-in-using-pyplot-in-julia/36234 "2020-03-20T00:44:51Z")

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Hi, I use Julia for optimization purposes. I use PyPlot for visualization of the results. I have used Windows and Mac computer so far, and there was no problem at all. I recently switched to a Windows computer, instal…

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## [Error opening too many connections](https://discourse.julialang.org/t/error-opening-too-many-connections/29371)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 5\
**Last updated:** [March 19, 2020, 11:46pm UTC](https://discourse.julialang.org/t/error-opening-too-many-connections/29371 "2020-03-19T23:46:19Z")

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I am trying to write a parallel algorithm to write to many files. Is there a way to detect how many connections I can open? Or a way to rate limit my code? ios = open.( "file".\*(1:3000), Ref("w"), ) gives error ERROR:…

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## [StringIndexError some time comes unexpectedly](https://discourse.julialang.org/t/stringindexerror-some-time-comes-unexpectedly/36174)

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**Author:** [@BMval](https://discourse.julialang.org/u/BMval)\
**Replies:** 2\
**Last updated:** [March 19, 2020, 11:40pm UTC](https://discourse.julialang.org/t/stringindexerror-some-time-comes-unexpectedly/36174 "2020-03-19T23:40:10Z")

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StringIndexError some time comes unexpectedly. Does anybody have this type of error? How to deal with it. I just do the next code to solve the problem, just change the index from 701 to 702 =)). Does anybody suggest ot…

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## [Warm Starts in JuMP 0.21 & GLPK 0.12.1](https://discourse.julialang.org/t/warm-starts-in-jump-0-21-glpk-0-12-1/36223)

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**Author:** [@azberman](https://discourse.julialang.org/u/azberman)\
**Replies:** 1\
**Last updated:** [March 19, 2020, 9:33pm UTC](https://discourse.julialang.org/t/warm-starts-in-jump-0-21-glpk-0-12-1/36223 "2020-03-19T21:33:17Z")

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When I run a version of the code below, I receive the following error: Warning: MathOptInterface.VariablePrimalStart() is not supported by MathOptInterface.Bridges.LazyBridgeOptimizer{GLPK.Optimizer}. This information w…

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## [JuliaCon 2020 Reviewers](https://discourse.julialang.org/t/juliacon-2020-reviewers/36154)

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**Author:** [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Replies:** 7\
**Last updated:** [March 19, 2020, 9:13pm UTC](https://discourse.julialang.org/t/juliacon-2020-reviewers/36154 "2020-03-19T21:13:12Z")

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Hey everyone, we’re still looking for reviewers for JuliaCon, so if you think you’ll have some time in about two weeks, sign up!

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## [TransformVariables.jl vs Bijectors.jl](https://discourse.julialang.org/t/transformvariables-jl-vs-bijectors-jl/29159)

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**Author:** [@cscherrer](https://discourse.julialang.org/u/cscherrer)\
**Replies:** 17\
**Last updated:** [March 19, 2020, 8:27pm UTC](https://discourse.julialang.org/t/transformvariables-jl-vs-bijectors-jl/29159 "2020-03-19T20:27:42Z")

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I’ve been using @Tamas\_Papp’s TransformVariables.jl for quite a while in my probabilistic programming work, and I’m very happy with it. Not long ago (weeks? months? one of those) I learned of Bijectors.jl, which looks …

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## [Using CSV issues](https://discourse.julialang.org/t/using-csv-issues/36211)

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**Author:** [@mayar](https://discourse.julialang.org/u/mayar)\
**Replies:** 13\
**Last updated:** [March 19, 2020, 8:08pm UTC](https://discourse.julialang.org/t/using-csv-issues/36211 "2020-03-19T20:08:18Z")

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Hello. I have an easy task which is to read a CSV file. I typed in my REPL this: using Pkg Pkg.add(“CSV”) then I write using CSV and press enter I get this msg “Julia has exited Press enter to start a new session” …

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## [Warning, invalid warm-start basis discarded](https://discourse.julialang.org/t/warning-invalid-warm-start-basis-discarded/26403)

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**Author:** [@Qun](https://discourse.julialang.org/u/Qun)\
**Replies:** 18\
**Last updated:** [March 19, 2020, 8:02pm UTC](https://discourse.julialang.org/t/warning-invalid-warm-start-basis-discarded/26403 "2020-03-19T20:02:26Z")

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I just learned how to use Julia 3 weeks ago. I used to use AIMMS to solve MIP problems. The considered MIP problem is about vehicle route problem. It involves over 50,000 binary variable. Without giving initial solution,…

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## [Parsing Markdown lists add paragraph to items](https://discourse.julialang.org/t/parsing-markdown-lists-add-paragraph-to-items/36169)

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**Author:** [@cdsousa](https://discourse.julialang.org/u/cdsousa)\
**Replies:** 4\
**Last updated:** [March 19, 2020, 6:36pm UTC](https://discourse.julialang.org/t/parsing-markdown-lists-add-paragraph-to-items/36169 "2020-03-19T18:36:50Z")

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Hi all, When parsing a Markdown list, julia\> m = Markdown.parse("- qwe\\n- rty") each item gets its own paragraph. The HTML conversion of the list includes the paragraphs (\<p\>\</p\>) in each item too: julia\> println(Ma…

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## [Behaviour of sparse array variables in JuMP](https://discourse.julialang.org/t/behaviour-of-sparse-array-variables-in-jump/36185)

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**Author:** [@martincornejo](https://discourse.julialang.org/u/martincornejo)\
**Replies:** 6\
**Last updated:** [March 19, 2020, 4:53pm UTC](https://discourse.julialang.org/t/behaviour-of-sparse-array-variables-in-jump/36185 "2020-03-19T16:53:17Z")

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Take as an example a vector v which is of type Boolean and has n elements. Based on this vector we build a variable array x of the same length of v , but from which only the indices corresponding with the non-zero elemen…

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## [Find simplex that contains point in triangulation](https://discourse.julialang.org/t/find-simplex-that-contains-point-in-triangulation/36181)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 3\
**Last updated:** [March 19, 2020, 4:43pm UTC](https://discourse.julialang.org/t/find-simplex-that-contains-point-in-triangulation/36181 "2020-03-19T16:43:58Z")

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Suppose I have a triangulation on a domain in \\mathbb{R}^n, where the element simplexes are given by their vertices. What is the recommended approach for finding which simplex contains a given point? Naively, I would ju…

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## [Very easy question about utf-8 string, I can't write the symbol "\\n" into file](https://discourse.julialang.org/t/very-easy-question-about-utf-8-string-i-cant-write-the-symbol-n-into-file/36195)

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**Author:** [@BMval](https://discourse.julialang.org/u/BMval)\
**Replies:** 0\
**Last updated:** [March 19, 2020, 4:16pm UTC](https://discourse.julialang.org/t/very-easy-question-about-utf-8-string-i-cant-write-the-symbol-n-into-file/36195 "2020-03-19T16:16:41Z")

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I have dataframe, where one of the columns is utf-8 string. I don’t have any problem to write and to read the dataset from csv file, But I have problem, when want to open the file in Stata or Excel. Or I totally confus…

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## [Questions about Julia Compilation Optimization Levels](https://discourse.julialang.org/t/questions-about-julia-compilation-optimization-levels/11296)

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**Author:** [@jinliangwei](https://discourse.julialang.org/u/jinliangwei)\
**Replies:** 3\
**Last updated:** [March 19, 2020, 4:15pm UTC](https://discourse.julialang.org/t/questions-about-julia-compilation-optimization-levels/11296 "2020-03-19T16:15:38Z")

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I couldn’t find documentation on optimization flags. Is there such a documentation? I know one can pass optimization flags (e.g. O0) when calling Julia. Is this O0 the same as Clang’s O0? What is the default optimizati…

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## [Define Truss Mesh in JuAFEM](https://discourse.julialang.org/t/define-truss-mesh-in-juafem/36191)

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**Author:** [@FrootLoops](https://discourse.julialang.org/u/FrootLoops)\
**Replies:** 3\
**Last updated:** [March 19, 2020, 4:01pm UTC](https://discourse.julialang.org/t/define-truss-mesh-in-juafem/36191 "2020-03-19T16:01:58Z")

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Hello everybody :slight\_smile: I am new to Julia and JuAFEM. Now I am trying to understand the linear Elasticity demo in juAFEM see. I understood a lot but I have big problems to adjust the code for my own purpose. I w…

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## [I've done it again: compat entry missing when registering a package](https://discourse.julialang.org/t/ive-done-it-again-compat-entry-missing-when-registering-a-package/36189)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 1\
**Last updated:** [March 19, 2020, 3:23pm UTC](https://discourse.julialang.org/t/ive-done-it-again-compat-entry-missing-when-registering-a-package/36189 "2020-03-19T15:23:48Z")

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I forgot to include a compat entry for a couple of packages when firing of request for that commit to be registered. Then the automatic merging into the registry fails (" Your new version pull request does not meet the…

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## [Do rules for good problems for benchmarking Julia exists?](https://discourse.julialang.org/t/do-rules-for-good-problems-for-benchmarking-julia-exists/35900)

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**Author:** [@KZiemian](https://discourse.julialang.org/u/KZiemian)\
**Replies:** 9\
**Last updated:** [March 19, 2020, 2:54pm UTC](https://discourse.julialang.org/t/do-rules-for-good-problems-for-benchmarking-julia-exists/35900 "2020-03-19T14:54:40Z")

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Few times I read discussions here, where someone try to check Julia speed, but take problem that was ill-suited for that. Two examples. Some times ago one person post examples in which for loop compute sum of arithmetic …

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## [Nonlinear solver and interpolation of array data](https://discourse.julialang.org/t/nonlinear-solver-and-interpolation-of-array-data/36187)

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**Author:** [@jleman](https://discourse.julialang.org/u/jleman)\
**Replies:** 0\
**Last updated:** [March 19, 2020, 2:30pm UTC](https://discourse.julialang.org/t/nonlinear-solver-and-interpolation-of-array-data/36187 "2020-03-19T14:30:57Z")

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I am using NLsolve to solve a single nonlinear function V = f(V,I), where V is the unknown voltage and I is a given current. The equation involves constraint by an arrester volt-current characteristic curve which I am …

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