# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1993

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

**Page:** 1994

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## [PowerModels and JuMP version conflict](https://discourse.julialang.org/t/powermodels-and-jump-version-conflict/24337)

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**Author:** [@jchen975](https://discourse.julialang.org/u/jchen975)\
**Replies:** 5\
**Last updated:** [May 18, 2019, 7:41pm UTC](https://discourse.julialang.org/t/powermodels-and-jump-version-conflict/24337 "2019-05-18T19:41:14Z")

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Hi there, I’m trying to use the PowerModels package for a power flow project, however I’m having the following issue: Anyone knows how to fix this?

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## [Use of MINLP in Julia](https://discourse.julialang.org/t/use-of-minlp-in-julia/22161)

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**Author:** [@angeloaliano1](https://discourse.julialang.org/u/angeloaliano1)\
**Replies:** 11\
**Last updated:** [May 18, 2019, 7:01pm UTC](https://discourse.julialang.org/t/use-of-minlp-in-julia/22161 "2019-05-18T19:01:27Z")

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Hello people, all rigth? I need to solve a nonlinear integer nonconvex problem. The objective and constraints are nonlinear functions. First question: What the ideal package and solve to solve this problem? Is there …

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## [Help me out with this syntax, please!](https://discourse.julialang.org/t/help-me-out-with-this-syntax-please/24287)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 12\
**Last updated:** [May 18, 2019, 3:47pm UTC](https://discourse.julialang.org/t/help-me-out-with-this-syntax-please/24287 "2019-05-18T15:47:28Z")

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I’m attempting to learn a new package and there is an operation being performed on two arrays in the example code that I don’t understand: +(yth\[3:end\], ysh...) yth is of type Array{Float64,1} and ysh is of type Array{…

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## [Thread to create a list of desired new packages](https://discourse.julialang.org/t/thread-to-create-a-list-of-desired-new-packages/24342)

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**Author:** [@Juan](https://discourse.julialang.org/u/Juan)\
**Replies:** 8\
**Last updated:** [May 18, 2019, 2:41pm UTC](https://discourse.julialang.org/t/thread-to-create-a-list-of-desired-new-packages/24342 "2019-05-18T14:41:42Z")

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Hello. It could be a good idea to have a thread where people show their interest in new Julia packages with features non-existent yet, and other people can also get ideas about what packages to develop. For example, I …

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## [Fixing aspect ratio and viewing angle of 3D plots using Plots.jl](https://discourse.julialang.org/t/fixing-aspect-ratio-and-viewing-angle-of-3d-plots-using-plots-jl/1556)

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**Author:** [@sonicsmooth](https://discourse.julialang.org/u/sonicsmooth)\
**Replies:** 8\
**Last updated:** [May 18, 2019, 1:17pm UTC](https://discourse.julialang.org/t/fixing-aspect-ratio-and-viewing-angle-of-3d-plots-using-plots-jl/1556 "2019-05-18T13:17:42Z")

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Hi, I’m trying out the various backends available for Plots.jl. I’m looking for the functions to set the viewing angle and aspect ratios for plot3d() plots. With gr and pyplot, the plots come out sqashed. With glvisua…

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## [Group as variable in statsplots](https://discourse.julialang.org/t/group-as-variable-in-statsplots/24352)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 0\
**Last updated:** [May 18, 2019, 12:58pm UTC](https://discourse.julialang.org/t/group-as-variable-in-statsplots/24352 "2019-05-18T12:58:15Z")

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Hi- I would like to pass a variable to the keyword group in StatsPlots, but I receive an error. Here is a simple example: using DataFrames,StatsPlots df = DataFrame(a=rand(100),b=rand(100),c=rand(1:2,100),d=rand(1:2,10…

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## [3D plot in VRML or U3D format](https://discourse.julialang.org/t/3d-plot-in-vrml-or-u3d-format/24351)

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**Author:** [@zimmermm](https://discourse.julialang.org/u/zimmermm)\
**Replies:** 0\
**Last updated:** [May 18, 2019, 12:57pm UTC](https://discourse.julialang.org/t/3d-plot-in-vrml-or-u3d-format/24351 "2019-05-18T12:57:42Z")

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Is anyone aware of a julia package that allows exporting 3d plots in VRML format? (Or better directly creates U3D pdf)

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## [PyCall imports anaconda package but fails to import package module](https://discourse.julialang.org/t/pycall-imports-anaconda-package-but-fails-to-import-package-module/24349)

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**Author:** [@zekeriya.sari](https://discourse.julialang.org/u/zekeriya.sari)\
**Replies:** 2\
**Last updated:** [May 18, 2019, 12:49pm UTC](https://discourse.julialang.org/t/pycall-imports-anaconda-package-but-fails-to-import-package-module/24349 "2019-05-18T12:49:05Z")

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I have built PyCall with anaconda python. I can import python packages, but cannot import submodules of the package. Here is the console output. julia\> versioninfo() Julia Version 1.1.0 Commit 80516ca202\* (2019-01-21 2…

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## [IJulia problem](https://discourse.julialang.org/t/ijulia-problem/24319)

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**Author:** [@Peter\_Waweru](https://discourse.julialang.org/u/Peter_Waweru)\
**Replies:** 12\
**Last updated:** [May 18, 2019, 10:36am UTC](https://discourse.julialang.org/t/ijulia-problem/24319 "2019-05-18T10:36:55Z")

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Every time i try to open a new Ijulia notebook i keep getting the following message: notebook() \[ Info: running setenv('C:\\Users\\admin\\.julia\\conda\\3\\Scripts\\jupyter.exe' notebook,\[“=::=::\\”, “USERDOMAIN\_ROAMINGPROFILE…

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## [How to launch workers on specific allocation node?](https://discourse.julialang.org/t/how-to-launch-workers-on-specific-allocation-node/24336)

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**Author:** [@aramirezreyes](https://discourse.julialang.org/u/aramirezreyes)\
**Replies:** 1\
**Last updated:** [May 17, 2019, 11:02pm UTC](https://discourse.julialang.org/t/how-to-launch-workers-on-specific-allocation-node/24336 "2019-05-17T23:02:01Z")

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Hi! I am doing some process that uses a ton of memory. The way I thought of doing it is to request 2 nodes via slurm and then send the memory-intensive part to a second node. My process looks like: salloc --nodes 2 -…

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## [Issues with undefined variables in loops?](https://discourse.julialang.org/t/issues-with-undefined-variables-in-loops/24249)

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**Author:** [@apattyn](https://discourse.julialang.org/u/apattyn)\
**Replies:** 5\
**Last updated:** [May 17, 2019, 7:39pm UTC](https://discourse.julialang.org/t/issues-with-undefined-variables-in-loops/24249 "2019-05-17T19:39:06Z")

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I am running a center finite difference method with temporally dependent boundary condition. The following code runs fine. dirichlet=1 for Δt in range(2,stop=length(t\_array)-1, step=1) for Δx in range(1,length=Nx) …

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## [Intent of \`Base.dump\` function](https://discourse.julialang.org/t/intent-of-base-dump-function/24321)

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**Author:** [@cce](https://discourse.julialang.org/u/cce)\
**Replies:** 5\
**Last updated:** [May 17, 2019, 6:55pm UTC](https://discourse.julialang.org/t/intent-of-base-dump-function/24321 "2019-05-17T18:55:50Z")

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As someone making custom data structures, I’m curious, how is dump meant to be used? Are there specific formatting constraints implied? What would constitute expected extension of this function to a user-defined type? …

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## [Itent of \`Base.summary\` function](https://discourse.julialang.org/t/itent-of-base-summary-function/24323)

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**Author:** [@cce](https://discourse.julialang.org/u/cce)\
**Replies:** 1\
**Last updated:** [May 17, 2019, 4:51pm UTC](https://discourse.julialang.org/t/itent-of-base-summary-function/24323 "2019-05-17T16:51:02Z")

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I’m curious, how is summary meant to be used? From the description, I get that summary should parrot the type information and the size of the object, but not the actual data. This seems quite useful, as a complement to d…

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## [DifferentialEquations.solve() speed](https://discourse.julialang.org/t/differentialequations-solve-speed/24329)

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**Author:** [@dg.aragones](https://discourse.julialang.org/u/dg.aragones)\
**Replies:** 3\
**Last updated:** [May 17, 2019, 4:42pm UTC](https://discourse.julialang.org/t/differentialequations-solve-speed/24329 "2019-05-17T16:42:32Z")

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I’m using DifferentialEquations.solve() to solve an ODE. It involves a lot of numerical parameters and functions. I get the solution correctly using the DifferentialEquations.VCABM3() method (Adams-Bashford-Moulton). How…

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## [Flux & Julia v. 1.1.1](https://discourse.julialang.org/t/flux-julia-v-1-1-1/24317)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 2\
**Last updated:** [May 17, 2019, 3:59pm UTC](https://discourse.julialang.org/t/flux-julia-v-1-1-1/24317 "2019-05-17T15:59:20Z")

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I just upgraded Julia to v. 1.1.1, and have updated packages. When I run using Flux, I get error messages. The status of Flux is: (v1.1) pkg\> status Flux Status \`C:\\Users\\my\_username\\.julia\\environments\\v1.1\\Projec…

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## [Back and forth transfer of data between GPU neural net and CPU simulation](https://discourse.julialang.org/t/back-and-forth-transfer-of-data-between-gpu-neural-net-and-cpu-simulation/24328)

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**Author:** [@HenriDeh](https://discourse.julialang.org/u/HenriDeh)\
**Replies:** 0\
**Last updated:** [May 17, 2019, 2:51pm UTC](https://discourse.julialang.org/t/back-and-forth-transfer-of-data-between-gpu-neural-net-and-cpu-simulation/24328 "2019-05-17T14:51:13Z")

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Hello, I have a neural network that interacts with a simulation. To accelerate its training, the network is transfered to my GPU. I implemented my simulation as a structure that handles other structures. In my toy exam…

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## [Plot x-axis with log scale](https://discourse.julialang.org/t/plot-x-axis-with-log-scale/24318)

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**Author:** [@tpylkko](https://discourse.julialang.org/u/tpylkko)\
**Replies:** 0\
**Last updated:** [May 17, 2019, 1:04pm UTC](https://discourse.julialang.org/t/plot-x-axis-with-log-scale/24318 "2019-05-17T13:04:58Z")

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I have two small questions related to plotting using the gr backend. How does one plot any plot so that the x-axis scale is log10, but that the numbers on the ticks are not 10-base exponents (i.e 1, 10 and 100 instead of…

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## [Methodswith question regarding methods from other modules](https://discourse.julialang.org/t/methodswith-question-regarding-methods-from-other-modules/24292)

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**Author:** [@Qiyamah](https://discourse.julialang.org/u/Qiyamah)\
**Replies:** 2\
**Last updated:** [May 17, 2019, 10:39am UTC](https://discourse.julialang.org/t/methodswith-question-regarding-methods-from-other-modules/24292 "2019-05-17T10:39:32Z")

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I have a question why methods with doesn’t return functions from other modules? module EE export identify identify(x::T) where T = x end module DD export f export…

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## [How use break in loop if ? ERROR: syntax: break or continue outside loop](https://discourse.julialang.org/t/how-use-break-in-loop-if-error-syntax-break-or-continue-outside-loop/24307)

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**Author:** [@programista](https://discourse.julialang.org/u/programista)\
**Replies:** 6\
**Last updated:** [May 17, 2019, 10:18am UTC](https://discourse.julialang.org/t/how-use-break-in-loop-if-error-syntax-break-or-continue-outside-loop/24307 "2019-05-17T10:18:34Z")

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julia\> if 1\>0 println("Stop") ;break else println("Go") end ERROR: syntax: break or continue outside loop Thanks Paul

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## [Problem with Macro expression evaluation](https://discourse.julialang.org/t/problem-with-macro-expression-evaluation/24281)

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**Author:** [@mwolff](https://discourse.julialang.org/u/mwolff)\
**Replies:** 9\
**Last updated:** [May 17, 2019, 9:54am UTC](https://discourse.julialang.org/t/problem-with-macro-expression-evaluation/24281 "2019-05-17T09:54:39Z")

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Hello, this is my first post and i need a little help with my macro problem macro foo(f, x) Expr(:call, f, x) end macro foo(exp) quote $(esc(exp)) end end function test(f) exp = Meta.parse(f) …

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## [Disable global RNG](https://discourse.julialang.org/t/disable-global-rng/20690)

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**Author:** [@robsmith11](https://discourse.julialang.org/u/robsmith11)\
**Replies:** 6\
**Last updated:** [May 17, 2019, 8:52am UTC](https://discourse.julialang.org/t/disable-global-rng/20690 "2019-05-17T08:52:43Z")

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In my simulation, I make frequent use of random numbers. I want everything to be reproducible, so I explicitly seed a single RNG and pass it around as needed. A few times now I’ve made the mistake of calling rand(n) ra…

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## [Directed Graph With Specific Locations](https://discourse.julialang.org/t/directed-graph-with-specific-locations/24304)

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**Author:** [@samslam](https://discourse.julialang.org/u/samslam)\
**Replies:** 1\
**Last updated:** [May 17, 2019, 6:17am UTC](https://discourse.julialang.org/t/directed-graph-with-specific-locations/24304 "2019-05-17T06:17:47Z")

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Hello As part of a university project I am solving a version of the Vehicle routing problem. I hope to illustrate the results with a directed graph. I have managed to generate such graphs using LightGraphs, but am havin…

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## [Problem calling string parse + eval from C++](https://discourse.julialang.org/t/problem-calling-string-parse-eval-from-c/23701)

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**Author:** [@alligatorme](https://discourse.julialang.org/u/alligatorme)\
**Replies:** 13\
**Last updated:** [May 17, 2019, 5:18am UTC](https://discourse.julialang.org/t/problem-calling-string-parse-eval-from-c/23701 "2019-05-17T05:18:56Z")

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s::String|\>Meta.parse|\>eval seems good in REPL,but not works when calling julia from C++. I have no idea why? but the following works in both: getproperty(Main,s::String|\>Symbol) return DataType define.jl: #!/usr/…

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## [SOS use on multidimensional arrays](https://discourse.julialang.org/t/sos-use-on-multidimensional-arrays/24282)

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**Author:** [@iharjunk](https://discourse.julialang.org/u/iharjunk)\
**Replies:** 5\
**Last updated:** [May 17, 2019, 4:48am UTC](https://discourse.julialang.org/t/sos-use-on-multidimensional-arrays/24282 "2019-05-17T04:48:23Z")

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Hello all! I am trying to use the new way of SOS2 constraints (MOI.SOS2) but since I have a 3-dimensional variable (the last dimension should be part of the SOS2 set), existing examples are not sufficient. Any hints how…

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## [Discussion: Context Dispatch - yes? no? questions? answers?](https://discourse.julialang.org/t/discussion-context-dispatch-yes-no-questions-answers/24194)

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**Author:** [@TsurHerman](https://discourse.julialang.org/u/TsurHerman)\
**Replies:** 11\
**Last updated:** [May 17, 2019, 4:20am UTC](https://discourse.julialang.org/t/discussion-context-dispatch-yes-no-questions-answers/24194 "2019-05-17T04:20:33Z")

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I wonder what the devs and community think of the direction of context dispatch as it has been recently presented in other various posts.

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## [Julia among 20 fastest growing freelancer skills in demand in US for Q1 of 2019 according to UpWork & TechRepublic](https://discourse.julialang.org/t/julia-among-20-fastest-growing-freelancer-skills-in-demand-in-us-for-q1-of-2019-according-to-upwork-techrepublic/24295)

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**Author:** [@kolia](https://discourse.julialang.org/u/kolia)\
**Replies:** 3\
**Last updated:** [May 17, 2019, 2:48am UTC](https://discourse.julialang.org/t/julia-among-20-fastest-growing-freelancer-skills-in-demand-in-us-for-q1-of-2019-according-to-upwork-techrepublic/24295 "2019-05-17T02:48:09Z")

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https://www.techrepublic.com/google-amp/article/ulia-kubernetes-and-hadoop-among-the-20-fastest-growing-freelancer-skills/ Don’t know much about how the gig market works and who tends to participate. Doesn’t sound too s…

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## [Nlopt returning zero after 0 to 2 iterations](https://discourse.julialang.org/t/nlopt-returning-zero-after-0-to-2-iterations/24293)

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**Author:** [@CPPhysics](https://discourse.julialang.org/u/CPPhysics)\
**Replies:** 0\
**Last updated:** [May 16, 2019, 7:54pm UTC](https://discourse.julialang.org/t/nlopt-returning-zero-after-0-to-2-iterations/24293 "2019-05-16T19:54:27Z")

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Firstly, I am minimizing a function which contains complex arrays and real arrays, with which there are a lot of operations and definitions which are pretty specific so I don’t know how to simplify it down into an exampl…

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## [Thread-local let bindings?](https://discourse.julialang.org/t/thread-local-let-bindings/24290)

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**Author:** [@robsmith11](https://discourse.julialang.org/u/robsmith11)\
**Replies:** 1\
**Last updated:** [May 16, 2019, 8:07pm UTC](https://discourse.julialang.org/t/thread-local-let-bindings/24290 "2019-05-16T20:07:06Z")

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I’m running into performance problems when my multithreaded code allocates heavily, so I’m trying to use let bindings to avoid reallocating large arrays, but I don’t see any way to make the bindings thread-local. For ex…

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## [\[ANN\] Nextjournal public launch](https://discourse.julialang.org/t/ann-nextjournal-public-launch/23913)

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**Author:** [@sdanisch](https://discourse.julialang.org/u/sdanisch)\
**Replies:** 7\
**Last updated:** [May 16, 2019, 7:28pm UTC](https://discourse.julialang.org/t/ann-nextjournal-public-launch/23913 "2019-05-16T19:28:45Z")

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:tada: We’ve opened signups on Nextjournal today and would love to get your feedback: Launch: Nextjournal Public Beta - Nextjournal. Nextjournal is a multi-language notebook platform with first class support for Julia (…

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## [Graph construction performance](https://discourse.julialang.org/t/graph-construction-performance/24288)

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**Author:** [@Azamat](https://discourse.julialang.org/u/Azamat)\
**Replies:** 2\
**Last updated:** [May 16, 2019, 6:15pm UTC](https://discourse.julialang.org/t/graph-construction-performance/24288 "2019-05-16T18:15:15Z")

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I need to construct a dense weighted undirected graph with ~20,000 vertices. Currently, I have the following code using LightGraphs, SimpleWeightedGraphs function main(n) g = SimpleWeightedGraph(n) for u ∈ verti…

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