# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1926

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

**Page:** 1927

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## [Handling INFEASIBLE\_OR\_UNBOUNDED](https://discourse.julialang.org/t/handling-infeasible-or-unbounded/28354)

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**Author:** [@tomerarnon](https://discourse.julialang.org/u/tomerarnon)\
**Replies:** 2\
**Last updated:** [September 5, 2019, 6:57pm UTC](https://discourse.julialang.org/t/handling-infeasible-or-unbounded/28354 "2019-09-05T18:57:53Z")

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Using JuMP, I am getting the return code INFEASIBLE\_OR\_UNBOUNDED, but in my case, knowing whether the problem is feasible is important. I.e. I should be handling an unbounded problem differently from an infeasible one. I…

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## [Use of Memory-mapped I/O](https://discourse.julialang.org/t/use-of-memory-mapped-i-o/28311)

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**Author:** [@sergevic](https://discourse.julialang.org/u/sergevic)\
**Replies:** 9\
**Last updated:** [September 5, 2019, 5:55pm UTC](https://discourse.julialang.org/t/use-of-memory-mapped-i-o/28311 "2019-09-05T17:55:10Z")

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I have a Julia code, version 1.2, which performs a lot of operations on a 10000 x 10000 Array . Due to OutOfMemory() error when I run the code, I’m exploring other options to run it, such as CUDA or Memory-mapping. Conce…

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## [What's the expected behaviour when using vector as dict(hash) key?](https://discourse.julialang.org/t/whats-the-expected-behaviour-when-using-vector-as-dict-hash-key/28431)

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**Author:** [@runapp](https://discourse.julialang.org/u/runapp)\
**Replies:** 5\
**Last updated:** [September 5, 2019, 5:15pm UTC](https://discourse.julialang.org/t/whats-the-expected-behaviour-when-using-vector-as-dict-hash-key/28431 "2019-09-05T17:15:08Z")

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a,k=Dict(),\[1\] a\[k\]=1 k\[1\]=2 print(a," ",a\[k\]," ");print(a\[\[1\]\]," ");println(a\[\[2\]\]); a\[k\]=2 print(a," ",a\[k\]," ");print(a\[\[1\]\]," ");println(a\[\[2\]\]); What should we expect? Or should we completely forbids using vectors(…

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## [Struggling with pmap](https://discourse.julialang.org/t/struggling-with-pmap/28432)

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**Author:** [@rveltz](https://discourse.julialang.org/u/rveltz)\
**Replies:** 8\
**Last updated:** [September 5, 2019, 4:45pm UTC](https://discourse.julialang.org/t/struggling-with-pmap/28432 "2019-09-05T16:45:58Z")

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Hello, I am struggling to understand why pmap is slow. I use the following fast function rand(). using Distributed addprocs(4) @everywhere using Random @everywhere g(x) = rand() @time map(g,1:100\_000\_000); 0.697132…

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## [How to create more helpful errors in nested interfaces](https://discourse.julialang.org/t/how-to-create-more-helpful-errors-in-nested-interfaces/28380)

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**Author:** [@zsunberg](https://discourse.julialang.org/u/zsunberg)\
**Replies:** 6\
**Last updated:** [September 5, 2019, 4:06pm UTC](https://discourse.julialang.org/t/how-to-create-more-helpful-errors-in-nested-interfaces/28380 "2019-09-05T16:06:35Z")

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Hi all, I am trying to throw more helpful errors in POMDPs.jl. This package has two nested interfaces. The explicit interface deals with explicit probability distributions; the generative interface samples from distribut…

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## [Julia-client 0.10.1 failing to install in Atom](https://discourse.julialang.org/t/julia-client-0-10-1-failing-to-install-in-atom/28436)

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**Author:** [@BioTurboNick](https://discourse.julialang.org/u/BioTurboNick)\
**Replies:** 2\
**Last updated:** [September 5, 2019, 4:05pm UTC](https://discourse.julialang.org/t/julia-client-0-10-1-failing-to-install-in-atom/28436 "2019-09-05T16:05:03Z")

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julia-client 0.10.1 failing to install in Atom. Tried uninstalling and installing from terminal and found same error. Error: \> @pfitzseb/node-pty-prebuilt@0.8.1-prebuilt3 install C:\\Users\\nicho\\AppData\\Local\\Temp\\apm-i…

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## [Plot a 3D Grid when solving Partial differential Equations](https://discourse.julialang.org/t/plot-a-3d-grid-when-solving-partial-differential-equations/20636)

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**Author:** [@Santiago\_Cuervo](https://discourse.julialang.org/u/Santiago_Cuervo)\
**Replies:** 3\
**Last updated:** [September 5, 2019, 3:06pm UTC](https://discourse.julialang.org/t/plot-a-3d-grid-when-solving-partial-differential-equations/20636 "2019-09-05T15:06:42Z")

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I would like to plot a 3D grid in which each cell has different values of properties. This is to view the results of solving partial differential equations PDE. In octave I plotted with patch function thanks

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## [Function with Gurobi model and optional solver parameters](https://discourse.julialang.org/t/function-with-gurobi-model-and-optional-solver-parameters/28327)

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**Author:** [@ibabeo](https://discourse.julialang.org/u/ibabeo)\
**Replies:** 3\
**Last updated:** [September 5, 2019, 1:05pm UTC](https://discourse.julialang.org/t/function-with-gurobi-model-and-optional-solver-parameters/28327 "2019-09-05T13:05:44Z")

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I’m trying to make a function with arguments that I can pass to the model if any, otherwise stay default. function mymip(; verbose = true, timelimit=false, mipfocus=false, rins=false) model = Model(with\_optimizer(G…

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## [Calling Fortran routine within Jump objective function](https://discourse.julialang.org/t/calling-fortran-routine-within-jump-objective-function/28347)

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**Author:** [@kuwi](https://discourse.julialang.org/u/kuwi)\
**Replies:** 2\
**Last updated:** [September 5, 2019, 1:00pm UTC](https://discourse.julialang.org/t/calling-fortran-routine-within-jump-objective-function/28347 "2019-09-05T13:00:03Z")

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Hello, I have a question regarding the call of Fortran routines within a Jump objective function. With the help of several forum posts, I managed to write Julia and Fortran code so I can call the Fortran routine from Ju…

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## [What happens if Julia Computing goes away?](https://discourse.julialang.org/t/what-happens-if-julia-computing-goes-away/28136)

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**Author:** [@ninjaaron](https://discourse.julialang.org/u/ninjaaron)\
**Replies:** 18\
**Last updated:** [September 5, 2019, 10:45am UTC](https://discourse.julialang.org/t/what-happens-if-julia-computing-goes-away/28136 "2019-09-05T10:45:41Z")

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So, I’m mostly a private Julia user. I like it very much, and I try to contribute to the community with docs and code, but I’m not really in a situation to purchase anything from Julia Computing. I had a candid conversat…

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## ["using" keyword in Julia](https://discourse.julialang.org/t/using-keyword-in-julia/28419)

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**Author:** [@bsnyh](https://discourse.julialang.org/u/bsnyh)\
**Replies:** 10\
**Last updated:** [September 5, 2019, 9:30am UTC](https://discourse.julialang.org/t/using-keyword-in-julia/28419 "2019-09-05T09:30:28Z")

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I’m a bit confused about the “using” keyword in Julia. using OpenStreetMapX distance1(a::ECEF, b::ECEF) =.... The above code works. On the other hand, if inside of a module, say module myModule, module myModule using …

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## [Updated StatsPlots and got error messages. How to fix?](https://discourse.julialang.org/t/updated-statsplots-and-got-error-messages-how-to-fix/28418)

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**Author:** [@IljaK91](https://discourse.julialang.org/u/IljaK91)\
**Replies:** 2\
**Last updated:** [September 5, 2019, 9:11am UTC](https://discourse.julialang.org/t/updated-statsplots-and-got-error-messages-how-to-fix/28418 "2019-09-05T09:11:11Z")

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I just updated some package and got the following error messages. What can I do about it? Updating registry at \`C:\\Users\\Ilja\\.julia\\registries\\General\` Updating git-repo \`https://github.com/JuliaRegistries/General.gi…

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## [Reading Flux code base](https://discourse.julialang.org/t/reading-flux-code-base/28387)

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**Author:** [@kadir-gunel](https://discourse.julialang.org/u/kadir-gunel)\
**Replies:** 2\
**Last updated:** [September 5, 2019, 7:19am UTC](https://discourse.julialang.org/t/reading-flux-code-base/28387 "2019-09-05T07:19:27Z")

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Dear all, I am trying to learn how to write good and efficient Julian code and Flux seems to be a good starting point. Due to that I started to read Flux code base and immediately, under src/layers/basic.jl, a code snip…

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## [Opening and closing file overhead](https://discourse.julialang.org/t/opening-and-closing-file-overhead/10635)

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**Author:** [@alirezamecheng](https://discourse.julialang.org/u/alirezamecheng)\
**Replies:** 8\
**Last updated:** [May 1, 2018, 1:25pm UTC](https://discourse.julialang.org/t/opening-and-closing-file-overhead/10635 "2018-05-01T13:25:32Z")

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Hello everyone, I\`m somehow new to programming. I have a question. Which algorithm has a better speed? which one do you recommend? function main() opening a file for loop \<doing some stuf\> writin…

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## [Ploting periods of time](https://discourse.julialang.org/t/ploting-periods-of-time/28400)

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**Author:** [@rredays](https://discourse.julialang.org/u/rredays)\
**Replies:** 1\
**Last updated:** [September 5, 2019, 5:05am UTC](https://discourse.julialang.org/t/ploting-periods-of-time/28400 "2019-09-05T05:05:43Z")

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Hello, I have a CSV file with a variable that is intervals of time written as HH:MM:SS, how can I import this data in a type that I can manipulate and plot? Thank you!

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## [Creating functions with ModelingToolkit for parallel usage](https://discourse.julialang.org/t/creating-functions-with-modelingtoolkit-for-parallel-usage/27632)

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**Author:** [@jamblejoe](https://discourse.julialang.org/u/jamblejoe)\
**Replies:** 4\
**Last updated:** [September 5, 2019, 4:22am UTC](https://discourse.julialang.org/t/creating-functions-with-modelingtoolkit-for-parallel-usage/27632 "2019-09-05T04:22:08Z")

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Hi, after figuring out how to use ModelingToolkit to create functions/derivates etc. I would like to run code generated by ModelingToolkit in parallel. E.g. solving the Lorenz system for multiple initial states, see the…

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## [String Index for DataFrames](https://discourse.julialang.org/t/string-index-for-dataframes/28390)

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**Author:** [@yakyak](https://discourse.julialang.org/u/yakyak)\
**Replies:** 1\
**Last updated:** [September 4, 2019, 10:27pm UTC](https://discourse.julialang.org/t/string-index-for-dataframes/28390 "2019-09-04T22:27:52Z")

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I am using the DataFrames package, and I would like to set a string column of it as the index. For example, let x = │ Row │ name │ val│ │ │ String │ String │ ├─────┼────────┼────────┤ │ 1 │ A │ 1│ │ 2 │ B…

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## [Use of Vector Libraries](https://discourse.julialang.org/t/use-of-vector-libraries/28062)

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**Author:** [@Crown421](https://discourse.julialang.org/u/Crown421)\
**Replies:** 5\
**Last updated:** [September 3, 2019, 11:57pm UTC](https://discourse.julialang.org/t/use-of-vector-libraries/28062 "2019-09-03T23:57:43Z")

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Dear all, TLDR: Are bindings to external vector math libraries still a thing? I am still very new to Julia, but rapidly progressing in search of speed. In this quest I found and used AppleAccelerate to great success, …

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## [A method to remove the use of runtime eval and invokelatest, as well as support closures in generated functions! Come with an implemented proptype](https://discourse.julialang.org/t/a-method-to-remove-the-use-of-runtime-eval-and-invokelatest-as-well-as-support-closures-in-generated-functions-come-with-an-implemented-proptype/27450)

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**Author:** [@thautwarm](https://discourse.julialang.org/u/thautwarm)\
**Replies:** 19\
**Last updated:** [September 4, 2019, 9:52pm UTC](https://discourse.julialang.org/t/a-method-to-remove-the-use-of-runtime-eval-and-invokelatest-as-well-as-support-closures-in-generated-functions-come-with-an-implemented-proptype/27450 "2019-09-04T21:52:13Z")

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Hi, every one, we’ve made something very, very useful and powerful today( You can check GG.jl for what we’ve provided. It’s originally motivated by solving an issue of @cscherrer 's Soss.jl: Find a way around \`invokela…

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## [Juno support for Julia 1.2.0 not ready yet?](https://discourse.julialang.org/t/juno-support-for-julia-1-2-0-not-ready-yet/27804)

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**Author:** [@Zhong\_Pan](https://discourse.julialang.org/u/Zhong_Pan)\
**Replies:** 3\
**Last updated:** [September 4, 2019, 9:13pm UTC](https://discourse.julialang.org/t/juno-support-for-julia-1-2-0-not-ready-yet/27804 "2019-09-04T21:13:29Z")

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Tried to use Juno with the newly released Julia 1.2.0 but after I started Julia from Juno I got the following: Press Enter to start Julia. Hold on tight while we are installing some packages for you. This should only …

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## [Information on auto-switching solvers](https://discourse.julialang.org/t/information-on-auto-switching-solvers/27853)

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**Author:** [@jamblejoe](https://discourse.julialang.org/u/jamblejoe)\
**Replies:** 2\
**Last updated:** [September 4, 2019, 9:11pm UTC](https://discourse.julialang.org/t/information-on-auto-switching-solvers/27853 "2019-09-04T21:11:26Z")

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Hi, I just want to know more about how the auto-switching algorithms in DifferentialEquations work. For example, when do they switch from non-stiff to stiff solver ? when do they switch back ? what happens to switchin…

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## [Typing special characters in Plot legends and titles](https://discourse.julialang.org/t/typing-special-characters-in-plot-legends-and-titles/24771)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 11\
**Last updated:** [September 4, 2019, 8:48pm UTC](https://discourse.julialang.org/t/typing-special-characters-in-plot-legends-and-titles/24771 "2019-09-04T20:48:02Z")

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I still didn’t find a practical way to type special characters in to a plot legend. In particular, I am trying to type an Angstrom (Å) character in an axis label. The situation is the following: In the REPL I can use t…

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## [Writing function that flexibly accepts string, string array, tuple, and others as argument](https://discourse.julialang.org/t/writing-function-that-flexibly-accepts-string-string-array-tuple-and-others-as-argument/28384)

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**Author:** [@Adam\_Fleischhacker](https://discourse.julialang.org/u/Adam_Fleischhacker)\
**Replies:** 3\
**Last updated:** [September 4, 2019, 7:25pm UTC](https://discourse.julialang.org/t/writing-function-that-flexibly-accepts-string-string-array-tuple-and-others-as-argument/28384 "2019-09-04T19:25:47Z")

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I am having trouble figuring out the recommended way to write a function that flexibly accepts any argument that can be converted into an array of strings. As a simple example, say I have the following function that sim…

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## [DifferentialEquations.jl FEM example](https://discourse.julialang.org/t/differentialequations-jl-fem-example/28128)

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**Author:** [@jw3126](https://discourse.julialang.org/u/jw3126)\
**Replies:** 31\
**Last updated:** [September 4, 2019, 5:28pm UTC](https://discourse.julialang.org/t/differentialequations-jl-fem-example/28128 "2019-09-04T17:28:58Z")

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I want to solve a time-dependent PDE on a somewhat nontrivial geometry. As a step in this direction I am looking for an example how to solve a PDE using DifferentialEquations.jl + some FEM package. For instance, the heat…

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## [Definition of unary operator inside a module, removes the \`Base\` definition](https://discourse.julialang.org/t/definition-of-unary-operator-inside-a-module-removes-the-base-definition/28371)

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**Author:** [@MatFi](https://discourse.julialang.org/u/MatFi)\
**Replies:** 3\
**Last updated:** [September 4, 2019, 4:24pm UTC](https://discourse.julialang.org/t/definition-of-unary-operator-inside-a-module-removes-the-base-definition/28371 "2019-09-04T16:24:21Z")

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i have a module in which a dispatch on + is defined module DriftDiff function (+)(l::Layer, r::Layer) ... end function b() 1.0+10.0 end end If i call now the function b() julia\> DriftDiff.b() ERROR: MethodErr…

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## [BSONqs.jl v0.5.0 - high speed fork of BSON.jl](https://discourse.julialang.org/t/bsonqs-jl-v0-5-0-high-speed-fork-of-bson-jl/25918)

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**Author:** [@richiejp](https://discourse.julialang.org/u/richiejp)\
**Replies:** 8\
**Last updated:** [September 4, 2019, 1:56pm UTC](https://discourse.julialang.org/t/bsonqs-jl-v0-5-0-high-speed-fork-of-bson-jl/25918 "2019-09-04T13:56:14Z")

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In short this library is intended to make loading Julia structs/types from their BSON representation\[1\] very efficient. I already wrote a post about this package, detailing some of my reasoning and optimisations. I have…

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## [Iterate over a SparseAxisArray container to retrieve variable values and index (jump 0.18+)](https://discourse.julialang.org/t/iterate-over-a-sparseaxisarray-container-to-retrieve-variable-values-and-index-jump-0-18/19498)

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**Author:** [@willu47](https://discourse.julialang.org/u/willu47)\
**Replies:** 2\
**Last updated:** [September 4, 2019, 1:44pm UTC](https://discourse.julialang.org/t/iterate-over-a-sparseaxisarray-container-to-retrieve-variable-values-and-index-jump-0-18/19498 "2019-09-04T13:44:26Z")

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I wish to iterate over the variables contained in a JuMP.SparseAxisArray so that I can write out variable values using JuMP.value(var), where var is an entry in the array. I would also like to obtain the value of the in…

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## [Lightweight IDE](https://discourse.julialang.org/t/lightweight-ide/28111)

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**Author:** [@Yifan\_Liu](https://discourse.julialang.org/u/Yifan_Liu)\
**Replies:** 37\
**Last updated:** [September 4, 2019, 12:25pm UTC](https://discourse.julialang.org/t/lightweight-ide/28111 "2019-09-04T12:25:24Z")

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I am currently using VSCode on both my Windows and Linux desktops. I noticed that VSCode uses a lot of RAM, even though I only have two extensions, which are Julia and Bracket Pair Colorizer. One selling point of VSCode …

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## [Mark a thread as more important than other threads (with respect to \`sleep\`)?](https://discourse.julialang.org/t/mark-a-thread-as-more-important-than-other-threads-with-respect-to-sleep/28350)

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**Author:** [@Krastanov](https://discourse.julialang.org/u/Krastanov)\
**Replies:** 1\
**Last updated:** [September 4, 2019, 12:09pm UTC](https://discourse.julialang.org/t/mark-a-thread-as-more-important-than-other-threads-with-respect-to-sleep/28350 "2019-09-04T12:09:02Z")

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I started using the following code pattern: my\_tasks = \[\] for i in my\_inputs task = @spawn my\_function(i) push!(my\_tasks, task) end while !all(istaskdone.(my\_tasks)) sleep(1) println("some progress mess…

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## [Plotting 2 functions](https://discourse.julialang.org/t/plotting-2-functions/28348)

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**Author:** [@Thalorn](https://discourse.julialang.org/u/Thalorn)\
**Replies:** 7\
**Last updated:** [September 4, 2019, 11:46am UTC](https://discourse.julialang.org/t/plotting-2-functions/28348 "2019-09-04T11:46:41Z")

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Hi, Im trying to plot my Chebyshev approximation using Printf using Plots pyplot() mutable struct Cheb\_struct c::Vector{Float64} min::Float64 max::Float64 end function cheb\_coeff(min::Float64, max::Float64…

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