# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1853

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

**Page:** 1854

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## [Replicating behavior of scipy.ndimate.gaussian\_filter](https://discourse.julialang.org/t/replicating-behavior-of-scipy-ndimate-gaussian-filter/32809)

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**Author:** [@bensetterholm](https://discourse.julialang.org/u/bensetterholm)\
**Replies:** 3\
**Last updated:** [December 31, 2019, 4:49pm UTC](https://discourse.julialang.org/t/replicating-behavior-of-scipy-ndimate-gaussian-filter/32809 "2019-12-31T16:49:12Z")

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I am trying to convert an old Python script to Julia. At one point, the script makes a call to scipy.ndimage.gaussian\_filter, for which I presume the Julia equivalent should be ImageFiltering.imfilter with Kernel.gaussia…

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## [Last puzzle of 2019](https://discourse.julialang.org/t/last-puzzle-of-2019/32820)

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**Author:** [@StevenSiew](https://discourse.julialang.org/u/StevenSiew)\
**Replies:** 5\
**Last updated:** [December 31, 2019, 1:58pm UTC](https://discourse.julialang.org/t/last-puzzle-of-2019/32820 "2019-12-31T13:58:14Z")

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“I am a time traveller!” said the time traveller. “Bullshit!” said I. “I will prove it to you. Get a fair dice. Color the side 1,2 and 3 as red. Color the sides 4 and 5 as green. And finally colour the side 6 as blue.” I…

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## [How can I make this more elegant/performant?](https://discourse.julialang.org/t/how-can-i-make-this-more-elegant-performant/32797)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 8\
**Last updated:** [December 31, 2019, 12:55pm UTC](https://discourse.julialang.org/t/how-can-i-make-this-more-elegant-performant/32797 "2019-12-31T12:55:08Z")

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Based on past experience, I have a feeling that I’ve horrendously over-engineered a solution to what seems like a simple problem. I have a vector of codes (numbers represented as strings) that I need to ‘collapse’ down. …

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## [What is the agreed abstraction for the "size" of finite collections?](https://discourse.julialang.org/t/what-is-the-agreed-abstraction-for-the-size-of-finite-collections/32757)

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**Author:** [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Replies:** 38\
**Last updated:** [December 31, 2019, 12:42pm UTC](https://discourse.julialang.org/t/what-is-the-agreed-abstraction-for-the-size-of-finite-collections/32757 "2019-12-31T12:42:27Z")

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Suppose I have a type that is a collection of samples (e.g. DataFrame). Unlike a simple Vector for which the name length can be used to retrieve the number of elements, my type doesn’t have the function length, but inste…

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## [DL\_LOAD\_PATH cleared outside of module](https://discourse.julialang.org/t/dl-load-path-cleared-outside-of-module/32769)

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**Author:** [@dmillard](https://discourse.julialang.org/u/dmillard)\
**Replies:** 3\
**Last updated:** [December 31, 2019, 12:38pm UTC](https://discourse.julialang.org/t/dl-load-path-cleared-outside-of-module/32769 "2019-12-31T12:38:26Z")

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I am writing a module Foo, which depends on ccalling some code in another part of my source tree. In my module, I push!(Libdl.DL\_LOAD\_PATH, "path/to/file"), and I’m able to find the .so according to some debugging. Howe…

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## [Is it a good idea to invest time in learning Julia for creating GUI applications for Windows?](https://discourse.julialang.org/t/is-it-a-good-idea-to-invest-time-in-learning-julia-for-creating-gui-applications-for-windows/32821)

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**Author:** [@vinod\_kc](https://discourse.julialang.org/u/vinod_kc)\
**Replies:** 2\
**Last updated:** [December 31, 2019, 12:24pm UTC](https://discourse.julialang.org/t/is-it-a-good-idea-to-invest-time-in-learning-julia-for-creating-gui-applications-for-windows/32821 "2019-12-31T12:24:30Z")

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Hi all, I am a hobby programmer and would like to create some gui applications for windows. My current aim is to use win32 API but if there is any better gui toolkits in Julia, i am ok with that. So this is my question,…

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## [Confidence interval with Plots and pgfplots()](https://discourse.julialang.org/t/confidence-interval-with-plots-and-pgfplots/31440)

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**Author:** [@juliauser](https://discourse.julialang.org/u/juliauser)\
**Replies:** 35\
**Last updated:** [December 31, 2019, 11:31am UTC](https://discourse.julialang.org/t/confidence-interval-with-plots-and-pgfplots/31440 "2019-12-31T11:31:54Z")

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Hi, I would like to run this type of code using Plots pgfplots() aa = rand(10) bb = rand(10) cc = rand(10) conf = \[aa-cc bb-cc\] p = plot(collect(1:10),cc) plot!(cc,ribbon=conf) This code works well is I replace pgfpl…

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## [What library do you suggest to parse HTML page and additionally navigate through the page](https://discourse.julialang.org/t/what-library-do-you-suggest-to-parse-html-page-and-additionally-navigate-through-the-page/32814)

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**Author:** [@BMval](https://discourse.julialang.org/u/BMval)\
**Replies:** 2\
**Last updated:** [December 31, 2019, 9:57am UTC](https://discourse.julialang.org/t/what-library-do-you-suggest-to-parse-html-page-and-additionally-navigate-through-the-page/32814 "2019-12-31T09:57:13Z")

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What library do you suggest to parse a HTML page and additionally navigate through the page?

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## [Install Julia with Anaconda on Windows10](https://discourse.julialang.org/t/install-julia-with-anaconda-on-windows10/19571)

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**Author:** [@mystis](https://discourse.julialang.org/u/mystis)\
**Replies:** 1\
**Last updated:** [December 31, 2019, 8:35am UTC](https://discourse.julialang.org/t/install-julia-with-anaconda-on-windows10/19571 "2019-12-31T08:35:10Z")

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Hello everyone, I’m struggling to have a working install of Julia alongside Anaconda on Windows 10. Basically I have a bunch of environments (Python & R) and I used to simply install Julia on the side and use with Juno. …

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## [How to sample a Data frame](https://discourse.julialang.org/t/how-to-sample-a-data-frame/32791)

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**Author:** [@imrankhan\_juliaLang](https://discourse.julialang.org/u/imrankhan_juliaLang)\
**Replies:** 10\
**Last updated:** [December 31, 2019, 5:08am UTC](https://discourse.julialang.org/t/how-to-sample-a-data-frame/32791 "2019-12-31T05:08:57Z")

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How can i sampling Data Frame? Like python data.sample() method NB: replace must need

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## [Memory allocation on multiple return values](https://discourse.julialang.org/t/memory-allocation-on-multiple-return-values/32805)

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**Author:** [@lucas711642](https://discourse.julialang.org/u/lucas711642)\
**Replies:** 3\
**Last updated:** [December 31, 2019, 4:01am UTC](https://discourse.julialang.org/t/memory-allocation-on-multiple-return-values/32805 "2019-12-31T04:01:56Z")

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Is there any way to avoid allocations on functions that return multiple values, when some of these values are mutable? For example: julia\> x = \[0\]; julia\> fun1(x) = @time((x, 1)); julia\> fun2(x) = (fun1(x); nothing); j…

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## [Running MNIST from model-zoo on Flux v0.10.0/Zygote/GPU](https://discourse.julialang.org/t/running-mnist-from-model-zoo-on-flux-v0-10-0-zygote-gpu/32810)

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**Author:** [@tanhevg](https://discourse.julialang.org/u/tanhevg)\
**Replies:** 2\
**Last updated:** [December 30, 2019, 11:42pm UTC](https://discourse.julialang.org/t/running-mnist-from-model-zoo-on-flux-v0-10-0-zygote-gpu/32810 "2019-12-30T23:42:31Z")

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Hello, I am trying to run the MNIST digit recognition from model-zoo using the latest Flux version with Zygote on a GPU. I had to make some tweaks to the code to make it run: https://github.com/tanhevg/model-zoo/blob/ta…

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## [Finding uses of a method?](https://discourse.julialang.org/t/finding-uses-of-a-method/32729)

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**Author:** [@gcv](https://discourse.julialang.org/u/gcv)\
**Replies:** 3\
**Last updated:** [December 30, 2019, 7:23pm UTC](https://discourse.julialang.org/t/finding-uses-of-a-method/32729 "2019-12-30T19:23:36Z")

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Is there a way to interrogate the Julia runtime and determine places where a method has been called from? (Context: Emacs development environment for Julia. This is for implementing search by cross-references.)

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## [Can not access geqrf!() function in LinearAlgebra Standard Library Package Julia 1.3.0](https://discourse.julialang.org/t/can-not-access-geqrf-function-in-linearalgebra-standard-library-package-julia-1-3-0/32796)

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**Author:** [@dataDiver](https://discourse.julialang.org/u/dataDiver)\
**Replies:** 3\
**Last updated:** [December 30, 2019, 3:03pm UTC](https://discourse.julialang.org/t/can-not-access-geqrf-function-in-linearalgebra-standard-library-package-julia-1-3-0/32796 "2019-12-30T15:03:24Z")

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Trying to run geqrf!() function from the manual using LinearAlgebra Q = rand(10, 5); tau = zeros(5) geqrf!(Q, tau) # ERROR: UndefVarError: geqrf! not defined

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## [Keeping Julia alive while running a web server in the background](https://discourse.julialang.org/t/keeping-julia-alive-while-running-a-web-server-in-the-background/8422)

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**Author:** [@NickNack](https://discourse.julialang.org/u/NickNack)\
**Replies:** 10\
**Last updated:** [December 30, 2019, 2:48pm UTC](https://discourse.julialang.org/t/keeping-julia-alive-while-running-a-web-server-in-the-background/8422 "2019-12-30T14:48:18Z")

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I’m using Mux.jl to run a web server. My code is in a module with the following structure: module MyApp using Mux # all app functions here function startserver() # setup routes here (using the functions above) …

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## [Why does rand() in threads slowdown speed in Julia 1.3](https://discourse.julialang.org/t/why-does-rand-in-threads-slowdown-speed-in-julia-1-3/32793)

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**Author:** [@Sijun](https://discourse.julialang.org/u/Sijun)\
**Replies:** 7\
**Last updated:** [December 30, 2019, 1:49pm UTC](https://discourse.julialang.org/t/why-does-rand-in-threads-slowdown-speed-in-julia-1-3/32793 "2019-12-30T13:49:47Z")

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In Julia 1.3 each thread has its own default global RNG. Calling rand() in each thread is safe. So the following code that calculates pi returns correct result: function par\_pi(n::Int) hits = zeros(Int, nthreads()) …

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## [Permutation / combination of elements of a matrix per row](https://discourse.julialang.org/t/permutation-combination-of-elements-of-a-matrix-per-row/32750)

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**Author:** [@tog](https://discourse.julialang.org/u/tog)\
**Replies:** 2\
**Last updated:** [December 30, 2019, 11:47am UTC](https://discourse.julialang.org/t/permutation-combination-of-elements-of-a-matrix-per-row/32750 "2019-12-30T11:47:32Z")

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Hi I have created a M x N matrix from which I want to create all elements resulting from i.e. if I have A = \[ 11 12 13 14; 21 22 23 24; 31 32 33 34\], I want to create: \[11; 21; 31\] \[11; 21; 32\] \[11; 21; 33\] \[11; 21; …

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## [Difference between f(1.0e-7) & f(1.0e-8)](https://discourse.julialang.org/t/difference-between-f-1-0e-7-f-1-0e-8/32779)

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**Author:** [@Stephen](https://discourse.julialang.org/u/Stephen)\
**Replies:** 14\
**Last updated:** [December 30, 2019, 8:03am UTC](https://discourse.julialang.org/t/difference-between-f-1-0e-7-f-1-0e-8/32779 "2019-12-30T08:03:47Z")

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the limit of the following function at 0 is 1, yet f(1.0e-8) gives 0 while f(1.0e-7) gives the correct answer, why? julia\> f(x)=2\*(1-x\*exp(-x)-exp(-x))/(1-exp(-x))^2 f (generic function with 1 method) julia\> f(1.0…

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## [Set default panel locations](https://discourse.julialang.org/t/set-default-panel-locations/32789)

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**Author:** [@yuxi.liu](https://discourse.julialang.org/u/yuxi.liu)\
**Replies:** 1\
**Last updated:** [December 30, 2019, 2:59am UTC](https://discourse.julialang.org/t/set-default-panel-locations/32789 "2019-12-30T02:59:40Z")

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Every time I open a new Juno, its panels are reset to a default configuration. I’d like to set default panel locations.

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## [Update variable in logged message without printing a new line?](https://discourse.julialang.org/t/update-variable-in-logged-message-without-printing-a-new-line/32755)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 5\
**Last updated:** [December 30, 2019, 12:49am UTC](https://discourse.julialang.org/t/update-variable-in-logged-message-without-printing-a-new-line/32755 "2019-12-30T00:49:43Z")

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I’m wondering if it’s possible to update a logged message without printing a new line. I’d like to log some information to the console on each iteration of a loop but, rather than printing a new @info statement on each i…

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## [\-1^(1/2) is Complex(-1^(1/2)) ==-1.0 + 0.0im?](https://discourse.julialang.org/t/1-1-2-is-complex-1-1-2-1-0-0-0im/32776)

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**Author:** [@programista](https://discourse.julialang.org/u/programista)\
**Replies:** 8\
**Last updated:** [December 29, 2019, 8:18pm UTC](https://discourse.julialang.org/t/1-1-2-is-complex-1-1-2-1-0-0-0im/32776 "2019-12-29T20:18:13Z")

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Why Complex(-1^(1/2))== -1.0 + 0.0im ??? Version 1.3.0-rc4.1 (2019-10-15) julia\> Complex(-1^(.5)) -1.0 + 0.0im julia\> sqrt(Complex(-1)) 0.0 + 1.0im julia\> Complex(-1^(1/2)) -1.0 + 0.0im julia\> 4^(1/2) 2.0 julia\> 9…

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## [Cannot install SymEngine](https://discourse.julialang.org/t/cannot-install-symengine/32753)

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**Author:** [@s\_1291](https://discourse.julialang.org/u/s_1291)\
**Replies:** 13\
**Last updated:** [December 29, 2019, 8:11pm UTC](https://discourse.julialang.org/t/cannot-install-symengine/32753 "2019-12-29T20:11:19Z")

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Hello, I’ve encountered some technical issues while trying to install some packages in Julia 1.3.0 in Windows 7: C:\\Windows\\system32\>julia \_ \_ \_ \_(\_)\_ | Documentation: https://docs.julialan…

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## [How to debug slow memory leak from threads?](https://discourse.julialang.org/t/how-to-debug-slow-memory-leak-from-threads/32784)

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**Author:** [@robsmith11](https://discourse.julialang.org/u/robsmith11)\
**Replies:** 0\
**Last updated:** [December 29, 2019, 6:26pm UTC](https://discourse.julialang.org/t/how-to-debug-slow-memory-leak-from-threads/32784 "2019-12-29T18:26:38Z")

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I’m running a calculation about 10 million times with different parameter sets. The input data is 50MB and the output of all 10 million runs adds up to 1GB. When I use multiple threads with 8 cores, I get a nearly perf…

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## [Julia 1.2.0 and Unicode character in Windows 10](https://discourse.julialang.org/t/julia-1-2-0-and-unicode-character-in-windows-10/29697)

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**Author:** [@Giovanni\_Di\_Stefano](https://discourse.julialang.org/u/Giovanni_Di_Stefano)\
**Replies:** 9\
**Last updated:** [December 29, 2019, 4:24pm UTC](https://discourse.julialang.org/t/julia-1-2-0-and-unicode-character-in-windows-10/29697 "2019-12-29T16:24:21Z")

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Hello! I installed Julia 1.2.0 on Windows 10, but when I type :turtle: , the turtle is not displayed, why?

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## [How to do L2 regularization with new Flux and Zygote](https://discourse.julialang.org/t/how-to-do-l2-regularization-with-new-flux-and-zygote/31756)

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**Author:** [@HenriDeh](https://discourse.julialang.org/u/HenriDeh)\
**Replies:** 2\
**Last updated:** [December 29, 2019, 3:39pm UTC](https://discourse.julialang.org/t/how-to-do-l2-regularization-with-new-flux-and-zygote/31756 "2019-12-29T15:39:31Z")

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I think this MWE used to work. Now I don’t know how to compute a norm penalty because the example in Flux documentation here is still using the old Tracked stuff. using Flux m = Dense(5,1) gs = Flux.gradient(Flux.para…

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## [How to contribute to existing package](https://discourse.julialang.org/t/how-to-contribute-to-existing-package/32749)

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**Author:** [@yuxi.liu](https://discourse.julialang.org/u/yuxi.liu)\
**Replies:** 6\
**Last updated:** [December 29, 2019, 11:22am UTC](https://discourse.julialang.org/t/how-to-contribute-to-existing-package/32749 "2019-12-29T11:22:48Z")

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How to develop existing packages? If I want to develop Example.jl, should I use pkg and pkg\> develop --local Example or fork the repo and then clone to desktop? If so, how do I load my local copy of package to Julia? H…

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## [Tree view Interact.jl](https://discourse.julialang.org/t/tree-view-interact-jl/32778)

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**Author:** [@Tomas\_Pevny](https://discourse.julialang.org/u/Tomas_Pevny)\
**Replies:** 0\
**Last updated:** [December 29, 2019, 9:26am UTC](https://discourse.julialang.org/t/tree-view-interact-jl/32778 "2019-12-29T09:26:24Z")

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Hi All, I would like to ask, if anyone has created a tree view (something like this How To Create a Tree View ) for Interact.jl. I would like to interactively show the schema of jsons in my package GitHub - CTUAvastLab/…

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## [Generating a type inheritance diagram](https://discourse.julialang.org/t/generating-a-type-inheritance-diagram/32773)

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**Author:** [@yuxi.liu](https://discourse.julialang.org/u/yuxi.liu)\
**Replies:** 3\
**Last updated:** [December 29, 2019, 4:57am UTC](https://discourse.julialang.org/t/generating-a-type-inheritance-diagram/32773 "2019-12-29T04:57:30Z")

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I want to see a type inheritance diagram of Julia’s classes, such as Base. Is there a tool to view it?

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## [What does Tuple{3} mean in StaticArrays?](https://discourse.julialang.org/t/what-does-tuple-3-mean-in-staticarrays/32774)

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**Author:** [@yuxi.liu](https://discourse.julialang.org/u/yuxi.liu)\
**Replies:** 1\
**Last updated:** [December 29, 2019, 4:46am UTC](https://discourse.julialang.org/t/what-does-tuple-3-mean-in-staticarrays/32774 "2019-12-29T04:46:49Z")

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In StaticArrays example, there is this line: similar\_type(m3) == SArray{Tuple{3,3},Int64,2,9} What is Tuple{3,3}? I thought Tuple, as a parameterized concrete type constructor, can’t take values, only types. The expla…

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## [Inference extremely slow for tiny program in Julia 0.6.4](https://discourse.julialang.org/t/inference-extremely-slow-for-tiny-program-in-julia-0-6-4/13854)

<div class="topic-metadata">

**Author:** [@bennedich](https://discourse.julialang.org/u/bennedich)\
**Replies:** 8\
**Last updated:** [December 29, 2019, 2:26am UTC](https://discourse.julialang.org/t/inference-extremely-slow-for-tiny-program-in-julia-0-6-4/13854 "2019-12-29T02:26:01Z")

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The following code runs very slowly in Julia 0.6.4 (~3 seconds), but quickly in Julia 0.7.0. Any idea what’s going on? function fun2() A .\*= A ./ y B .\*= B ./ y C .\*= C ./ y end function fun1() x = 1 …

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