# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1968

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

**Page:** 1969

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## [Strange promote\_rule()?](https://discourse.julialang.org/t/strange-promote-rule/25762)

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**Author:** [@tomtom](https://discourse.julialang.org/u/tomtom)\
**Replies:** 6\
**Last updated:** [July 1, 2019, 11:00am UTC](https://discourse.julialang.org/t/strange-promote-rule/25762 "2019-07-01T11:00:46Z")

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compared to promote\_type(), promote\_rule() seems to be asymmetric and wrong? julia\> promote\_type(Float16, Float32) Float32 julia\> promote\_type(Float32, Float16) Float32 julia\> promote\_rule(Float16, Float32) # why??…

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## [How to use Flux for a general non-linear minimization](https://discourse.julialang.org/t/how-to-use-flux-for-a-general-non-linear-minimization/24111)

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**Author:** [@misha\_mikhasenko](https://discourse.julialang.org/u/misha_mikhasenko)\
**Replies:** 1\
**Last updated:** [July 1, 2019, 9:58am UTC](https://discourse.julialang.org/t/how-to-use-flux-for-a-general-non-linear-minimization/24111 "2019-07-01T09:58:52Z")

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I am trying to apply great features Flux for likelihood minimization problem. Using ML language, losses for all training data points are summed up, there is just a function LLH() to be minimized. Is there an easy hack…

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## [How to remove invisible characters in JSON](https://discourse.julialang.org/t/how-to-remove-invisible-characters-in-json/25847)

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**Author:** [@Gavinclarke](https://discourse.julialang.org/u/Gavinclarke)\
**Replies:** 2\
**Last updated:** [July 1, 2019, 9:57am UTC](https://discourse.julialang.org/t/how-to-remove-invisible-characters-in-json/25847 "2019-07-01T09:57:16Z")

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I am querying a json which is returned with invisible characters at the beginning specifically 0xef, 0xbb, 0xbf in UTF8, I have tried replacing them in string from with replace with the code: clean = replace(unclean, “…

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## [CImGui Images, graphics and other stuff - one problem and documentation needed](https://discourse.julialang.org/t/cimgui-images-graphics-and-other-stuff-one-problem-and-documentation-needed/25418)

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**Author:** [@wiktorkujawa](https://discourse.julialang.org/u/wiktorkujawa)\
**Replies:** 11\
**Last updated:** [July 1, 2019, 9:57am UTC](https://discourse.julialang.org/t/cimgui-images-graphics-and-other-stuff-one-problem-and-documentation-needed/25418 "2019-07-01T09:57:01Z")

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The problem that I have is that after clicking Generate plot in my program, I want to generate new image(without the old one). After clicking Generate plot, I want to generate new image(without the old one). Here is…

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## [\[ANN\] FluxOptTools](https://discourse.julialang.org/t/ann-fluxopttools/25888)

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**Author:** [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)\
**Replies:** 0\
**Last updated:** [July 1, 2019, 9:17am UTC](https://discourse.julialang.org/t/ann-fluxopttools/25888 "2019-07-01T09:17:48Z")

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FluxOptTools.jl This package contains some utilities to enhance training of Flux.jl models. Train using Optim Optim.jl can be used to train Flux models (if Flux is on branch sf/zygote\_updated), here’s an example how u…

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## [Keychain in Julia](https://discourse.julialang.org/t/keychain-in-julia/25884)

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**Author:** [@sambitdash](https://discourse.julialang.org/u/sambitdash)\
**Replies:** 0\
**Last updated:** [July 1, 2019, 4:29am UTC](https://discourse.julialang.org/t/keychain-in-julia/25884 "2019-07-01T04:29:28Z")

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Hi All, I am looking for a keychain where I can store some cryptographic keys safely. The the keys should be encrypted for most part save actual cryptographic operations. This is mostly to avoid stealing of crypto infor…

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## [What does this mean: Plot(...)](https://discourse.julialang.org/t/what-does-this-mean-plot/25852)

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**Author:** [@GdMacmillan](https://discourse.julialang.org/u/GdMacmillan)\
**Replies:** 3\
**Last updated:** [July 1, 2019, 6:46am UTC](https://discourse.julialang.org/t/what-does-this-mean-plot/25852 "2019-07-01T06:46:23Z")

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when I type p3 = Gadfly.plot(first(sort!(df1, \[:count\], rev=true), 50), x = :word, y = :count, Geom.bar ) it plots a bar plot with vertical bars When I type p3 = Gadfly.plot(first(sort!(df1, \[:count\], rev=tru…

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## [What is the right way to construct and then run a Julia function programmatically?](https://discourse.julialang.org/t/what-is-the-right-way-to-construct-and-then-run-a-julia-function-programmatically/25845)

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**Author:** [@Nathaniel](https://discourse.julialang.org/u/Nathaniel)\
**Replies:** 13\
**Last updated:** [July 1, 2019, 3:28am UTC](https://discourse.julialang.org/t/what-is-the-right-way-to-construct-and-then-run-a-julia-function-programmatically/25845 "2019-07-01T03:28:54Z")

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I would like to write a Julia program that does the following: Build up a big, complicated Expr object using metaprogramming Compile that expression into a Julia function Call that function repeatedly with different ar…

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## [Unsatisfiable requirements detected for package JWAS](https://discourse.julialang.org/t/unsatisfiable-requirements-detected-for-package-jwas/25879)

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**Author:** [@min](https://discourse.julialang.org/u/min)\
**Replies:** 5\
**Last updated:** [July 1, 2019, 2:54am UTC](https://discourse.julialang.org/t/unsatisfiable-requirements-detected-for-package-jwas/25879 "2019-07-01T02:54:42Z")

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julia\> using Pkg julia\> Pkg.add(“JWAS”) Updating registry at C:\\Users\\iq600\\.julia\\registries\\General Updating git-repo https://github.com/JuliaRegistries/General.git Resolving package versions… ERROR: Unsatisfiable…

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## [Inverse of a view of a symmetric matrix](https://discourse.julialang.org/t/inverse-of-a-view-of-a-symmetric-matrix/25877)

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**Author:** [@fipelle](https://discourse.julialang.org/u/fipelle)\
**Replies:** 3\
**Last updated:** [July 1, 2019, 1:35am UTC](https://discourse.julialang.org/t/inverse-of-a-view-of-a-symmetric-matrix/25877 "2019-07-01T01:35:09Z")

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Hi, I am trying to compute the inverse of a view of a symmetric matrix via: using LinearAlgebra V=Symmetric(rand(10,10)+50\*I); V\_view = @view V\[1:5,1:5\]; V\_view\_inv = inv(V\_view); However, it does not work and I get t…

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## [Trouble understanding how scopes work when using @testset](https://discourse.julialang.org/t/trouble-understanding-how-scopes-work-when-using-testset/25854)

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**Author:** [@JKRT](https://discourse.julialang.org/u/JKRT)\
**Replies:** 9\
**Last updated:** [June 30, 2019, 3:12pm UTC](https://discourse.julialang.org/t/trouble-understanding-how-scopes-work-when-using-testset/25854 "2019-06-30T15:12:53Z")

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Hello! This is a continuation of the discussion here: Lettings macros get the entire scope from where it is called through implicit parameter · Issue #32453 · JuliaLang/julia · GitHub You see this really bothers me. Th…

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## [\[ANN\] UMAP.jl, a pure Julia implementation of Uniform Manifold Approximation and Projection](https://discourse.julialang.org/t/ann-umap-jl-a-pure-julia-implementation-of-uniform-manifold-approximation-and-projection/19829)

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**Author:** [@dillondaudert](https://discourse.julialang.org/u/dillondaudert)\
**Replies:** 1\
**Last updated:** [June 30, 2019, 9:47pm UTC](https://discourse.julialang.org/t/ann-umap-jl-a-pure-julia-implementation-of-uniform-manifold-approximation-and-projection/19829 "2019-06-30T21:47:55Z")

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UMAP.jl is a pure Julia implementation of the UMAP dimension reduction algorithm. From the abstract: UMAP (Uniform Manifold Approximation and Projection) is a novel manifold learning technique for dimension reduction. …

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## [Multiple Axis Plot](https://discourse.julialang.org/t/multiple-axis-plot/25869)

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**Author:** [@Santiago\_Cuervo](https://discourse.julialang.org/u/Santiago_Cuervo)\
**Replies:** 0\
**Last updated:** [June 30, 2019, 9:31pm UTC](https://discourse.julialang.org/t/multiple-axis-plot/25869 "2019-06-30T21:31:12Z")

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I’m trying to make a recipe for multiple axis plot, but I don’t know how. The twinx() keyword does not work. Here is the recipe i’m working on. I’d like to have another one or more axis to visualize this data in a bett…

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## [An Observable of an abstract type](https://discourse.julialang.org/t/an-observable-of-an-abstract-type/25865)

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**Author:** [@yakir12](https://discourse.julialang.org/u/yakir12)\
**Replies:** 1\
**Last updated:** [June 30, 2019, 8:42pm UTC](https://discourse.julialang.org/t/an-observable-of-an-abstract-type/25865 "2019-06-30T20:42:25Z")

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I have an Observable (from https://github.com/JuliaGizmos/Observables.jl) that could contain any concrete subtype of some common abstract type. Is this the best way to do it? using Observables o = Observable(Any\[\]) o\[\] …

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## [Using Cxx to interface to a C++ library](https://discourse.julialang.org/t/using-cxx-to-interface-to-a-c-library/24969)

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**Author:** [@hros](https://discourse.julialang.org/u/hros)\
**Replies:** 9\
**Last updated:** [June 30, 2019, 6:25pm UTC](https://discourse.julialang.org/t/using-cxx-to-interface-to-a-c-library/24969 "2019-06-30T18:25:54Z")

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I am trying to interface a c++ library (ntl) and am thinking of using the Cxx module. Specifically, I’m looking to use the included C++ types directly in Julia, and perform mathematical operations on them using the C++ …

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## [Stop Julia from opening at login](https://discourse.julialang.org/t/stop-julia-from-opening-at-login/25842)

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**Author:** [@rverdier](https://discourse.julialang.org/u/rverdier)\
**Replies:** 4\
**Last updated:** [June 30, 2019, 2:14pm UTC](https://discourse.julialang.org/t/stop-julia-from-opening-at-login/25842 "2019-06-30T14:14:46Z")

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On Mac OS 10.14.3, whenever I log in, Julia opens. Since I don’t want that, I clicked the ‘open at login’ option for Julia in the dock. Now it opens TWO copies whenever I log in. There are lots of solutions on the Web…

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## [It is too easy to beat AlphaGo.jl](https://discourse.julialang.org/t/it-is-too-easy-to-beat-alphago-jl/19518)

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**Author:** [@rapasite](https://discourse.julialang.org/u/rapasite)\
**Replies:** 13\
**Last updated:** [June 30, 2019, 3:51am UTC](https://discourse.julialang.org/t/it-is-too-easy-to-beat-alphago-jl/19518 "2019-06-30T03:51:48Z")

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At least on https://fluxml.ai/experiments/go/, suffice to create an “eye” and grow from it. maybe the network is not trained enough but maybe something is wrong @MikeInnes @tejank10 I am just starting machine learnin…

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## [Remote process can not call function](https://discourse.julialang.org/t/remote-process-can-not-call-function/25821)

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**Author:** [@jamblejoe](https://discourse.julialang.org/u/jamblejoe)\
**Replies:** 7\
**Last updated:** [June 29, 2019, 9:56pm UTC](https://discourse.julialang.org/t/remote-process-can-not-call-function/25821 "2019-06-29T21:56:03Z")

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Hi, this is my first try to setup remote processes in Julia and I am running into the following error: julia\> using Distributed julia\> @everywhere function worker(); println("Hi");end julia\> addprocs(\[("ip-address",1…

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## [Getindex generator](https://discourse.julialang.org/t/getindex-generator/25843)

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**Author:** [@yakir12](https://discourse.julialang.org/u/yakir12)\
**Replies:** 3\
**Last updated:** [June 29, 2019, 7:25pm UTC](https://discourse.julialang.org/t/getindex-generator/25843 "2019-06-29T19:25:47Z")

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I can’t find it, although I’m sure it’s been answered before: how do I (efficiently) access the 'n’th element of a generator? a = (i for i in 1:10^6) a\[3\]

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## [Encoding UTF16 JSONs as UTF8](https://discourse.julialang.org/t/encoding-utf16-jsons-as-utf8/25833)

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**Author:** [@Gavinclarke](https://discourse.julialang.org/u/Gavinclarke)\
**Replies:** 2\
**Last updated:** [June 29, 2019, 7:17pm UTC](https://discourse.julialang.org/t/encoding-utf16-jsons-as-utf8/25833 "2019-06-29T19:17:57Z")

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I have a Jason I am getting with http.get. However, the Jason is encoded in UTF16 and I believe this is preventing it from being parsed correctly. what is the fasI am wondering what the best way to get, encode from UTF1…

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## [Naive use of BSON not working as expected](https://discourse.julialang.org/t/naive-use-of-bson-not-working-as-expected/25740)

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**Author:** [@ablaom](https://discourse.julialang.org/u/ablaom)\
**Replies:** 15\
**Last updated:** [June 29, 2019, 7:09pm UTC](https://discourse.julialang.org/t/naive-use-of-bson-not-working-as-expected/25740 "2019-06-29T19:09:35Z")

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Sorry, I am a beginner to BSON and am a little stuck. I have a struct Foo defined entirely in some package A. Package B imports A, defines an instance f=A.Foo() and serializes that instance using BSON. Now if, in the R…

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## [Nested derivatives with DiffEqFlux.jl](https://discourse.julialang.org/t/nested-derivatives-with-diffeqflux-jl/25714)

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**Author:** [@adam-coogan](https://discourse.julialang.org/u/adam-coogan)\
**Replies:** 4\
**Last updated:** [June 29, 2019, 4:47pm UTC](https://discourse.julialang.org/t/nested-derivatives-with-diffeqflux-jl/25714 "2019-06-29T16:47:24Z")

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I’m working on a physics project where (very roughly) I need to integrate some Hamiltonian equations of motion and differentiate functions of the resulting trajectories with respect to a parameter \\alpha. More precisely,…

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## [Broadcasting in macros](https://discourse.julialang.org/t/broadcasting-in-macros/25797)

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**Author:** [@DrChainsaw](https://discourse.julialang.org/u/DrChainsaw)\
**Replies:** 4\
**Last updated:** [June 29, 2019, 4:37pm UTC](https://discourse.julialang.org/t/broadcasting-in-macros/25797 "2019-06-29T16:37:31Z")

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What is wrong with this macro: julia\> macro lessthanthree(vec) return :($vec .\< 3) end @lessthanthree (macro with 1 method) julia\> @lessthanthree 1:6 ERROR: UndefVarError: .\< not defined Stacktrace: \[1\] …

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## [Error in diffeq\_fd command of DiffEqFlux](https://discourse.julialang.org/t/error-in-diffeq-fd-command-of-diffeqflux/25837)

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**Author:** [@JunichiFukui](https://discourse.julialang.org/u/JunichiFukui)\
**Replies:** 4\
**Last updated:** [June 29, 2019, 4:05pm UTC](https://discourse.julialang.org/t/error-in-diffeq-fd-command-of-diffeqflux/25837 "2019-06-29T16:05:06Z")

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I’m trying to run neural partial differential equation code on the web site (Neural Jump SDEs (Jump Diffusions) and Neural PDEs - Stochastic Lifestyle). Thanks Chris for publishing the interest code. When I run the code…

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## [Significant decrease in performance after seemingly irrelevant changes](https://discourse.julialang.org/t/significant-decrease-in-performance-after-seemingly-irrelevant-changes/25796)

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**Author:** [@Tusike](https://discourse.julialang.org/u/Tusike)\
**Replies:** 16\
**Last updated:** [June 29, 2019, 3:29pm UTC](https://discourse.julialang.org/t/significant-decrease-in-performance-after-seemingly-irrelevant-changes/25796 "2019-06-29T15:29:57Z")

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Hi! I recently revised some aspects of a large project I’m working on, just moving around some data/functions without altering the behavior of the code. However, it resulted in significant decrease in performance in see…

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## [\[ANN\] BinningAnalysis.jl](https://discourse.julialang.org/t/ann-binninganalysis-jl/25840)

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**Author:** [@carstenbauer](https://discourse.julialang.org/u/carstenbauer)\
**Replies:** 0\
**Last updated:** [June 29, 2019, 2:07pm UTC](https://discourse.julialang.org/t/ann-binninganalysis-jl/25840 "2019-06-29T14:07:59Z")

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Hi all, let me announce the small and lightweight BinningAnalysis.jl. The package provides tools to estimate standard errors and autocorrelation times of correlated time series. A typical example is a Markov chain obta…

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## [Efficiency of matrix data operations](https://discourse.julialang.org/t/efficiency-of-matrix-data-operations/25768)

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**Author:** [@FujiwaraTakumiEH](https://discourse.julialang.org/u/FujiwaraTakumiEH)\
**Replies:** 10\
**Last updated:** [June 29, 2019, 1:01pm UTC](https://discourse.julialang.org/t/efficiency-of-matrix-data-operations/25768 "2019-06-29T13:01:59Z")

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Background: I have the following matrix is raw data,for example: a=\\left\[ \\begin{matrix} 1 & 2 & 3 \\\\ 4 & 5 & 6 \\\\ 7 & 8 & 9 \\\\ &...& \\end{matrix} \\right\] , b=\\left\[ \\begin{matrix} 1 & 2 & 3 & 5 \\\\ …

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## [How to create/display multiple plot windows in GR.jl?](https://discourse.julialang.org/t/how-to-create-display-multiple-plot-windows-in-gr-jl/25817)

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**Author:** [@Zhong\_Pan](https://discourse.julialang.org/u/Zhong_Pan)\
**Replies:** 4\
**Last updated:** [June 29, 2019, 11:58am UTC](https://discourse.julialang.org/t/how-to-create-display-multiple-plot-windows-in-gr-jl/25817 "2019-06-29T11:58:19Z")

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I searched online and found no example of doing so; the API does not seem to contain function that supports this either. I already opened an issue at the GitHub project, but no response yet. But this feature is often ne…

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## [Recommended env variables for most performant parallel/multithreading?](https://discourse.julialang.org/t/recommended-env-variables-for-most-performant-parallel-multithreading/25631)

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**Author:** [@alvrg](https://discourse.julialang.org/u/alvrg)\
**Replies:** 3\
**Last updated:** [June 25, 2019, 3:00pm UTC](https://discourse.julialang.org/t/recommended-env-variables-for-most-performant-parallel-multithreading/25631 "2019-06-25T15:00:39Z")

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Hi all, I have two questions. What are the recommended values of the env variables (JULIA\_NUM\_THREADS, MKL/OPENBLAS\_NUM\_THREADS, …) if I want to speed up my code using Threads.@threads? To what should I set those v…

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## [Axis theme for custom type in AbstractPlotting](https://discourse.julialang.org/t/axis-theme-for-custom-type-in-abstractplotting/23101)

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**Author:** [@grero](https://discourse.julialang.org/u/grero)\
**Replies:** 1\
**Last updated:** [June 29, 2019, 5:46am UTC](https://discourse.julialang.org/t/axis-theme-for-custom-type-in-abstractplotting/23101 "2019-06-29T05:46:40Z")

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Hi, I am trying out AbstractPlotting recipes for a custom type, and I have a question about theming. I understand that extending AbstractPlotting.default\_theme is the way to pass attributes to my plot, as shown the mole…

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