# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1887

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

**Page:** 1888

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## [Can DataFrames.jl handle multi-dimensional arrays](https://discourse.julialang.org/t/can-dataframes-jl-handle-multi-dimensional-arrays/30727)

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**Author:** [@00krishna](https://discourse.julialang.org/u/00krishna)\
**Replies:** 6\
**Last updated:** [November 6, 2019, 8:56pm UTC](https://discourse.julialang.org/t/can-dataframes-jl-handle-multi-dimensional-arrays/30727 "2019-11-06T20:56:58Z")

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I was wondering if DataFrames.jl can handle multi-dimensional arrays, meaning an array with 3 or more dimensions. I can run using DataFrames DataFrame(rand(3,4) and that works fine. But if I try: DataFrame(rand(3,4,…

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## [How to plot columns of a matrix on a single line graph in Julia](https://discourse.julialang.org/t/how-to-plot-columns-of-a-matrix-on-a-single-line-graph-in-julia/30794)

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**Author:** [@NITISH\_KUMAR](https://discourse.julialang.org/u/NITISH_KUMAR)\
**Replies:** 8\
**Last updated:** [November 6, 2019, 2:48pm UTC](https://discourse.julialang.org/t/how-to-plot-columns-of-a-matrix-on-a-single-line-graph-in-julia/30794 "2019-11-06T14:48:11Z")

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Hi everyone!. Please guide in plotting the columns of matrices (Preferably subplot type). thank you :slight\_smile:

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## [Hello: new member | old lurker](https://discourse.julialang.org/t/hello-new-member-old-lurker/29731)

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**Author:** [@pontus](https://discourse.julialang.org/u/pontus)\
**Replies:** 7\
**Last updated:** [November 6, 2019, 5:53pm UTC](https://discourse.julialang.org/t/hello-new-member-old-lurker/29731 "2019-11-06T17:53:43Z")

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Good day fine Julians! Taking a moment to introduce myself and thank you all for this wonderful community! Have an Engineering but no CS background, and am learning Julia as my first programming language, starting may…

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## [How do I plot?](https://discourse.julialang.org/t/how-do-i-plot/30783)

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**Author:** [@Emir\_Sahin](https://discourse.julialang.org/u/Emir_Sahin)\
**Replies:** 3\
**Last updated:** [November 6, 2019, 5:45pm UTC](https://discourse.julialang.org/t/how-do-i-plot/30783 "2019-11-06T17:45:32Z")

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xfirst=rand(-5:5) for n=1:100 a=rand(-0.1:0.1) xnew=xfirst+(xfirst\*a) if mainfonk(xnew)\>mainfonk(xfirst) xfirst=xnew println(mainfonk(xfirst)) end end Hi. I am working hill climbing in julia. I am trying…

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## [What's the "right" way to broadcast vector-valued functions?](https://discourse.julialang.org/t/whats-the-right-way-to-broadcast-vector-valued-functions/30232)

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**Author:** [@jlchan](https://discourse.julialang.org/u/jlchan)\
**Replies:** 4\
**Last updated:** [November 6, 2019, 4:15pm UTC](https://discourse.julialang.org/t/whats-the-right-way-to-broadcast-vector-valued-functions/30232 "2019-11-06T16:15:04Z")

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I’m trying to figure out the “right” way to combine broadcasting with functions for vector-valued inputs/outputs. For example, the following function defines foo through broadcasted operations. using LinearAlgebra fun…

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## [Get intuition on how to improve matmul code](https://discourse.julialang.org/t/get-intuition-on-how-to-improve-matmul-code/30799)

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**Author:** [@davidbp](https://discourse.julialang.org/u/davidbp)\
**Replies:** 14\
**Last updated:** [November 6, 2019, 5:31pm UTC](https://discourse.julialang.org/t/get-intuition-on-how-to-improve-matmul-code/30799 "2019-11-06T17:31:02Z")

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Hello, After playing a little bit with the most naive matmul blocked version I have found on the internet I was wondering what could I do to improve the performance. function matmul\_blocked\_1!(A, B, C) bs = 10 …

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## [How to keep a reference for C structure to avoid GC?](https://discourse.julialang.org/t/how-to-keep-a-reference-for-c-structure-to-avoid-gc/9310)

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**Author:** [@tk3369](https://discourse.julialang.org/u/tk3369)\
**Replies:** 25\
**Last updated:** [November 6, 2019, 5:14pm UTC](https://discourse.julialang.org/t/how-to-keep-a-reference-for-c-structure-to-avoid-gc/9310 "2019-11-06T17:14:16Z")

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I need to pass a struct that may contain an array of its own type to a C library. To achieve that, I use the pointer function to obtain an address and encode that in an UInt64 field (as expected by the C library). I’ve…

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## [Julia and GoogleMaps](https://discourse.julialang.org/t/julia-and-googlemaps/29693)

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**Author:** [@Dervis](https://discourse.julialang.org/u/Dervis)\
**Replies:** 11\
**Last updated:** [November 6, 2019, 4:47pm UTC](https://discourse.julialang.org/t/julia-and-googlemaps/29693 "2019-11-06T16:47:22Z")

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Dear all, I 'd like to plot my GPS points (LLA) on Googlemaps with Julia and also would like to plot a route between two GPS points on GoogleMaps again via julia. I did a little bit of research on the forums but couldn’…

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## [Julia's DataFrames.jl performance on join benchmark](https://discourse.julialang.org/t/julias-dataframes-jl-performance-on-join-benchmark/30788)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 1\
**Last updated:** [November 6, 2019, 4:09pm UTC](https://discourse.julialang.org/t/julias-dataframes-jl-performance-on-join-benchmark/30788 "2019-11-06T16:09:57Z")

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Please see Database-like ops benchmark There is a new Join benchmark where Julia’s DataFrames.jl is in the last 2 spots most of the time. And takes is 30x slower than R’s {data.table} in some of the benchmarks. This re…

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## [Code using Flux slow on GPU](https://discourse.julialang.org/t/code-using-flux-slow-on-gpu/30696)

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**Author:** [@johnbb](https://discourse.julialang.org/u/johnbb)\
**Replies:** 9\
**Last updated:** [November 6, 2019, 4:09pm UTC](https://discourse.julialang.org/t/code-using-flux-slow-on-gpu/30696 "2019-11-06T16:09:16Z")

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I am trying to make Julia code running on GPU for quantile function regression where the probability distribution is specified by a linear combination of Bernstein polynomials and its parameters are linked to the covaria…

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## [How to set xtick names in Gadfly plots?](https://discourse.julialang.org/t/how-to-set-xtick-names-in-gadfly-plots/30795)

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**Author:** [@rio](https://discourse.julialang.org/u/rio)\
**Replies:** 1\
**Last updated:** [November 6, 2019, 2:20pm UTC](https://discourse.julialang.org/t/how-to-set-xtick-names-in-gadfly-plots/30795 "2019-11-06T14:20:50Z")

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Hi all, I would like to see letters A,B,C,D in the xticks positions of the plot example below. Please, how cold I set this? using Gadfly, Random set\_default\_plot\_size(14cm, 8cm) Random.seed!(1234) plot(x=rand(10), y=ra…

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## [Some JuMP variables values are out of bounds](https://discourse.julialang.org/t/some-jump-variables-values-are-out-of-bounds/26008)

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**Author:** [@KestutisMa](https://discourse.julialang.org/u/KestutisMa)\
**Replies:** 7\
**Last updated:** [November 6, 2019, 2:20pm UTC](https://discourse.julialang.org/t/some-jump-variables-values-are-out-of-bounds/26008 "2019-11-06T14:20:35Z")

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Hi, I have problem while running optimization of our biophysical model (which is using Markov chain methodology): some parameter values during JuMP optimisation procedure are set to “0” by autodiff, but this is out of bo…

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## [Case insensitive/ Fuzzy Completions](https://discourse.julialang.org/t/case-insensitive-fuzzy-completions/29955)

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**Author:** [@jarrison](https://discourse.julialang.org/u/jarrison)\
**Replies:** 3\
**Last updated:** [November 6, 2019, 12:57pm UTC](https://discourse.julialang.org/t/case-insensitive-fuzzy-completions/29955 "2019-11-06T12:57:21Z")

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I am a very lazy person and want to know if the functionality exists for this. If not, can anyone give me a quick course in the completion handling api? I was unfortunately a little too slow to grasp the big picture from…

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## [Plotting a 3D Surface](https://discourse.julialang.org/t/plotting-a-3d-surface/17143)

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**Author:** [@oliver](https://discourse.julialang.org/u/oliver)\
**Replies:** 15\
**Last updated:** [November 5, 2019, 10:43pm UTC](https://discourse.julialang.org/t/plotting-a-3d-surface/17143 "2019-11-05T22:43:06Z")

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How would I plot the surface f(x,y)=xy-y-x+1 between \\sqrt2\\leq y\\leq2 using PyPlot; x = collect(Float16, range(-2,length=100,stop=2)); y = collect(Float16, range(sqrt(2),length=100, stop=2)); z = (x.\*y).-y.-x.+1; surf(…

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## [How can I read a MetaGraph in GML format?](https://discourse.julialang.org/t/how-can-i-read-a-metagraph-in-gml-format/30786)

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**Author:** [@Diego\_Javier\_Zea](https://discourse.julialang.org/u/Diego_Javier_Zea)\
**Replies:** 0\
**Last updated:** [November 6, 2019, 10:18am UTC](https://discourse.julialang.org/t/how-can-i-read-a-metagraph-in-gml-format/30786 "2019-11-06T10:18:26Z")

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Hi! I have a graph with edge and node metadata in GML format, how can I read it into a MetaGraph? Thanks in advance,

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## [Usage of the \`\[compat\]\` section in \`Project.toml\` and \`Compat.toml\` in the registry](https://discourse.julialang.org/t/usage-of-the-compat-section-in-project-toml-and-compat-toml-in-the-registry/30785)

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**Author:** [@heliosdrm](https://discourse.julialang.org/u/heliosdrm)\
**Replies:** 0\
**Last updated:** [November 6, 2019, 9:50am UTC](https://discourse.julialang.org/t/usage-of-the-compat-section-in-project-toml-and-compat-toml-in-the-registry/30785 "2019-11-06T09:50:06Z")

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Related to Please be mindful of version bounds and semantic versioning when tagging your packages - #86 by Tamas\_Papp, but I would like to put this as an independent question. If I understand correctly, the information …

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## [How do I turn this into arrays?](https://discourse.julialang.org/t/how-do-i-turn-this-into-arrays/30784)

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**Author:** [@AlexanderChen](https://discourse.julialang.org/u/AlexanderChen)\
**Replies:** 2\
**Last updated:** [November 6, 2019, 9:43am UTC](https://discourse.julialang.org/t/how-do-i-turn-this-into-arrays/30784 "2019-11-06T09:43:51Z")

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Hi, This code works but the output is 1 single array: \[ 10 - i - j for i in collect(0:9), j in collect(0:9) if 10- i - j \> 0\] output: \[10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 7, 6, 5, 4, 3, 2, 1, 8, 7, 6, 5, 4, 3, 2, 1,…

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## [JuliaPro Uses PowerShell Scripts](https://discourse.julialang.org/t/juliapro-uses-powershell-scripts/30770)

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**Author:** [@dburch](https://discourse.julialang.org/u/dburch)\
**Replies:** 1\
**Last updated:** [November 6, 2019, 8:49am UTC](https://discourse.julialang.org/t/juliapro-uses-powershell-scripts/30770 "2019-11-06T08:49:08Z")

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My company uses installed software that blocks PowerShell scripts from running on my computer. Because of this, I cannot start Julia inside JuliaPro. Is there a way to start Julia in JuliaPro without the PowerShell scrip…

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## [Fast solving of a cubic equation?](https://discourse.julialang.org/t/fast-solving-of-a-cubic-equation/30779)

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**Author:** [@longemen3000](https://discourse.julialang.org/u/longemen3000)\
**Replies:** 6\
**Last updated:** [November 6, 2019, 6:09am UTC](https://discourse.julialang.org/t/fast-solving-of-a-cubic-equation/30779 "2019-11-06T06:09:16Z")

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i just want to know if of all the existing polynomial root solving packages, there is one that solves cubic equations with the exact formula (cardano’s method)

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## [Repl in Juno, type enter and report an error](https://discourse.julialang.org/t/repl-in-juno-type-enter-and-report-an-error/30688)

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**Author:** [@nick-stu](https://discourse.julialang.org/u/nick-stu)\
**Replies:** 5\
**Last updated:** [November 6, 2019, 2:34am UTC](https://discourse.julialang.org/t/repl-in-juno-type-enter-and-report-an-error/30688 "2019-11-06T02:34:12Z")

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I successfully installed Julia, atom, and Juno (including july-client, etc.) julia version 0.6.4 It runs successfully directly from the command line. But in the repl in atom, pressing enter causes the following err…

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## [Doto macro?](https://discourse.julialang.org/t/doto-macro/30766)

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**Author:** [@Orbots](https://discourse.julialang.org/u/Orbots)\
**Replies:** 5\
**Last updated:** [November 6, 2019, 1:24am UTC](https://discourse.julialang.org/t/doto-macro/30766 "2019-11-06T01:24:23Z")

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Is there something like clojure’s doto macro readily available? doto - clojure.core | ClojureDocs - Community-Powered Clojure Documentation and Examples. “Evaluates x then calls all of the methods and functions with t…

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## [How do you feel about Julia Observer?](https://discourse.julialang.org/t/how-do-you-feel-about-julia-observer/18577)

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**Author:** [@djsegal](https://discourse.julialang.org/u/djsegal)\
**Replies:** 21\
**Last updated:** [November 3, 2019, 3:56am UTC](https://discourse.julialang.org/t/how-do-you-feel-about-julia-observer/18577 "2019-11-03T03:56:02Z")

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As we’re getting to the two year mark of JuliaObserver, I thought it was a good time to check in w/ you guys. Currently, the website has ~1k weekly users, with an average session time of 3-4 minutes. http://juliaobserv…

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## [Best julian way to populate empty dataframes?](https://discourse.julialang.org/t/best-julian-way-to-populate-empty-dataframes/30768)

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**Author:** [@bashonubuntu](https://discourse.julialang.org/u/bashonubuntu)\
**Replies:** 2\
**Last updated:** [November 6, 2019, 12:50am UTC](https://discourse.julialang.org/t/best-julian-way-to-populate-empty-dataframes/30768 "2019-11-06T00:50:24Z")

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Hello, Often times in what I code, I need to populate an empty dataframe based on some pre-existing dataframe which is called inside a function. For example, function populate\_meta\_data(data::R) where {R\<:DataFrame} …

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## [Backpropagate compat bounds](https://discourse.julialang.org/t/backpropagate-compat-bounds/30737)

<div class="topic-metadata">

**Author:** [@carstenbauer](https://discourse.julialang.org/u/carstenbauer)\
**Replies:** 10\
**Last updated:** [November 5, 2019, 11:53pm UTC](https://discourse.julialang.org/t/backpropagate-compat-bounds/30737 "2019-11-05T23:53:19Z")

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As has been pointed out by @fredrikekre in Please be mindful of version bounds and semantic versioning when tagging your packages - #20 by fredrikekre, compat entries do not backpropagate to older versions of a package. …

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## [Zygote foreigncall expression error](https://discourse.julialang.org/t/zygote-foreigncall-expression-error/30739)

<div class="topic-metadata">

**Author:** [@LudiWin](https://discourse.julialang.org/u/LudiWin)\
**Replies:** 3\
**Last updated:** [November 5, 2019, 9:00pm UTC](https://discourse.julialang.org/t/zygote-foreigncall-expression-error/30739 "2019-11-05T21:00:35Z")

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Hi, to get into Julia I started implementing different machine learning algorithms. Last night i implemented a GP just to see how that would work. Here’s the code so far: using LinearAlgebra, Random, Distributions us…

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## [How to start with 3D scater plots?](https://discourse.julialang.org/t/how-to-start-with-3d-scater-plots/30730)

<div class="topic-metadata">

**Author:** [@programista](https://discourse.julialang.org/u/programista)\
**Replies:** 3\
**Last updated:** [November 5, 2019, 8:47pm UTC](https://discourse.julialang.org/t/how-to-start-with-3d-scater-plots/30730 "2019-11-05T20:47:07Z")

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I am starting with 3D plots, How to start with 3D scater plots? Paul

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## [Atom Juno won't open Julia if directory path contains spaces](https://discourse.julialang.org/t/atom-juno-wont-open-julia-if-directory-path-contains-spaces/8659)

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**Author:** [@clinton](https://discourse.julialang.org/u/clinton)\
**Replies:** 2\
**Last updated:** [January 29, 2018, 8:48pm UTC](https://discourse.julialang.org/t/atom-juno-wont-open-julia-if-directory-path-contains-spaces/8659 "2018-01-29T20:48:48Z")

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I tried to switch to using the atom-integrated REPL in the latest Juno patch. However, it doesn’t seem to work with a space in the Julia directory path (this is on Windows). The full path is: C:\\Users\\Clinton Name\\AppDa…

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## ["Module Parsers is missing from the cache"](https://discourse.julialang.org/t/module-parsers-is-missing-from-the-cache/30765)

<div class="topic-metadata">

**Author:** [@BioTurboNick](https://discourse.julialang.org/u/BioTurboNick)\
**Replies:** 1\
**Last updated:** [November 5, 2019, 7:08pm UTC](https://discourse.julialang.org/t/module-parsers-is-missing-from-the-cache/30765 "2019-11-05T19:08:53Z")

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I made some changes to my package and then tried running it with workers. Now I get these errors on the workers: Warning: Module Parsers with build ID 337459641262600 is missing from the cache. Cannot write cache file …

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## [Running a function in parallel](https://discourse.julialang.org/t/running-a-function-in-parallel/30756)

<div class="topic-metadata">

**Author:** [@Patrik\_Waldmann](https://discourse.julialang.org/u/Patrik_Waldmann)\
**Replies:** 2\
**Last updated:** [November 5, 2019, 6:14pm UTC](https://discourse.julialang.org/t/running-a-function-in-parallel/30756 "2019-11-05T18:14:59Z")

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I need help getting a function to run in parallel. I want to distribute both data and packages to all workers, see the following example (which doesn’t work): #Simulated data (n observations, p variables, tr truevariabl…

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## [How to read the @objective command?](https://discourse.julialang.org/t/how-to-read-the-objective-command/30752)

<div class="topic-metadata">

**Author:** [@RaquelSantos](https://discourse.julialang.org/u/RaquelSantos)\
**Replies:** 5\
**Last updated:** [November 5, 2019, 5:33pm UTC](https://discourse.julialang.org/t/how-to-read-the-objective-command/30752 "2019-11-05T17:33:30Z")

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@objective (m,Min,sum (LS \[i, j\]\*C\[i, j\] for i, j ∈ 1:f)) How to make this expression read the for i,j. The way I did the error appears: syntax: invalid iteration specification

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