# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1844

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

**Page:** 1845

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## [How to initialize a subset of params of a NN](https://discourse.julialang.org/t/how-to-initialize-a-subset-of-params-of-a-nn/33423)

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**Author:** [@shrirams](https://discourse.julialang.org/u/shrirams)\
**Replies:** 2\
**Last updated:** [January 16, 2020, 8:22am UTC](https://discourse.julialang.org/t/how-to-initialize-a-subset-of-params-of-a-nn/33423 "2020-01-16T08:22:21Z")

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Suppose I have a trained neural net nn1 = Flux.Chain(Dense(90, 60, relu), Dense(60, 30, relu), Dense(30,1)). I am aware that I can access the weights corresponding to the first 2 layers by params(nn1\[1\]), params(nn1…

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## [How to install Juno from the command line?](https://discourse.julialang.org/t/how-to-install-juno-from-the-command-line/33377)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 14\
**Last updated:** [January 16, 2020, 8:56am UTC](https://discourse.julialang.org/t/how-to-install-juno-from-the-command-line/33377 "2020-01-16T08:56:53Z")

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I am trying to build a docker image with Juno pre-installed. However, after adding the line RUN apm install uber-juno and when I run Atom, it will show the usually, “Juno: Installing Atom packages” pop-ups and it is q…

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## [Finite element mesh interface](https://discourse.julialang.org/t/finite-element-mesh-interface/33325)

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**Author:** [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Replies:** 19\
**Last updated:** [January 16, 2020, 8:51am UTC](https://discourse.julialang.org/t/finite-element-mesh-interface/33325 "2020-01-16T08:51:24Z")

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Dear all, Do you know a paper, book or any published material that attempts to define an interface for general finite element meshes? I am in the process of finalizing a proposal interface, and would like to share it w…

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## [Any syntax to specify whether a function should or should not be compiled?](https://discourse.julialang.org/t/any-syntax-to-specify-whether-a-function-should-or-should-not-be-compiled/33125)

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**Author:** [@nxtruong](https://discourse.julialang.org/u/nxtruong)\
**Replies:** 9\
**Last updated:** [January 16, 2020, 7:18am UTC](https://discourse.julialang.org/t/any-syntax-to-specify-whether-a-function-should-or-should-not-be-compiled/33125 "2020-01-16T07:18:37Z")

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I’m converting from Matlab (and some Python) to Julia. Honestly the time-to-first-plot issue of Julia really bothers me frequently. I almost never plot anything in Julia for that reason; instead, I save my (not so large)…

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## [Julian "trackpy" alternative?](https://discourse.julialang.org/t/julian-trackpy-alternative/32634)

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**Author:** [@francesco.alemanno](https://discourse.julialang.org/u/francesco.alemanno)\
**Replies:** 4\
**Last updated:** [January 16, 2020, 6:00am UTC](https://discourse.julialang.org/t/julian-trackpy-alternative/32634 "2020-01-16T06:00:57Z")

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does anyone know or is working on a Particle Tracking toolkit for Julia, in python there is a good package called “trackpy” : https://github.com/soft-matter/trackpy is there any workable alternative for Julia?

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## [How to save and restore a Float64 value to disk](https://discourse.julialang.org/t/how-to-save-and-restore-a-float64-value-to-disk/33378)

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**Author:** [@StevenSiew](https://discourse.julialang.org/u/StevenSiew)\
**Replies:** 8\
**Last updated:** [January 16, 2020, 5:32am UTC](https://discourse.julialang.org/t/how-to-save-and-restore-a-float64-value-to-disk/33378 "2020-01-16T05:32:02Z")

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n = sqrt(2.0) """ How do I save my Float64 value in variable n to disk in such a way that I can 1. restore back to another variable y 2. such that y is Float64 and has the exact value as n 3. This restoration will work…

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## [Concatenating iterables without allocating memory](https://discourse.julialang.org/t/concatenating-iterables-without-allocating-memory/33282)

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**Author:** [@Jakub\_Wronowski](https://discourse.julialang.org/u/Jakub_Wronowski)\
**Replies:** 34\
**Last updated:** [January 16, 2020, 4:06am UTC](https://discourse.julialang.org/t/concatenating-iterables-without-allocating-memory/33282 "2020-01-16T04:06:57Z")

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Hi, for a library I am working now I need to find minimum and maximum values. I am looking elegant way to express that. signal1 = rand(10000000) signal2 = rand(10000000) @time lo, hi = extrema(vcat(signal1, signal2)) …

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## [Problem with Mosek](https://discourse.julialang.org/t/problem-with-mosek/33427)

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**Author:** [@Shuvomoy\_Das\_Gupta](https://discourse.julialang.org/u/Shuvomoy_Das_Gupta)\
**Replies:** 4\
**Last updated:** [January 16, 2020, 1:51am UTC](https://discourse.julialang.org/t/problem-with-mosek/33427 "2020-01-16T01:51:29Z")

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Dear All, I am trying to solve an SDP using Convex.jl and Mosek. My Mosek version is 9.1.11, and Convex.jl version is 0.12.6. My Julia version is 1.3. I have installed Mosek with an academic license, and it seems to be …

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## [OpenBLAS vs MKL](https://discourse.julialang.org/t/openblas-vs-mkl/17362)

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**Author:** [@carstenbauer](https://discourse.julialang.org/u/carstenbauer)\
**Replies:** 7\
**Last updated:** [January 16, 2020, 1:01am UTC](https://discourse.julialang.org/t/openblas-vs-mkl/17362 "2020-01-16T01:01:30Z")

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I just build Julia 1.0.1 on a cluster and linked it against MKL (2019). As a simple benchmark, I compared the performance of squaring a 1000 x 1000 matrix against the Julia binaries from the website (OpenBLAS). I remembe…

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## [DataFrame | multiply set of colums](https://discourse.julialang.org/t/dataframe-multiply-set-of-colums/33421)

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**Author:** [@BMval](https://discourse.julialang.org/u/BMval)\
**Replies:** 4\
**Last updated:** [January 16, 2020, 12:09am UTC](https://discourse.julialang.org/t/dataframe-multiply-set-of-colums/33421 "2020-01-16T00:09:33Z")

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Would you suggest, I have a list of columns (many of them). How to multiply all of them. I know how to sum, but I have no idea, how to multiply sum.(eachrow(qf\[:,\[:a,:b\]\])) Thanks

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## [Looking for advice on threading](https://discourse.julialang.org/t/looking-for-advice-on-threading/33301)

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**Author:** [@Paul\_Soderlind](https://discourse.julialang.org/u/Paul_Soderlind)\
**Replies:** 6\
**Last updated:** [January 15, 2020, 9:25pm UTC](https://discourse.julialang.org/t/looking-for-advice-on-threading/33301 "2020-01-15T21:25:47Z")

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Are there any (fairly simple) examples of how to work with Threads.@threads? Background;: so far I have tried splitting up my computations in threaded chunks and eventually recombine the results from the chunks, similar…

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## [Thread- and process-based parallelisms in Transducers.jl (+ some news)](https://discourse.julialang.org/t/thread-and-process-based-parallelisms-in-transducers-jl-some-news/32285)

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**Author:** [@tkf](https://discourse.julialang.org/u/tkf)\
**Replies:** 5\
**Last updated:** [January 15, 2020, 9:06pm UTC](https://discourse.julialang.org/t/thread-and-process-based-parallelisms-in-transducers-jl-some-news/32285 "2020-01-15T21:06:04Z")

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It’s been a while since I added parallelism supports in Transducers.jl but I’ve never announced this feature properly. I just added a few utility functions and a tutorial so I think it’s good timing to do this. Quoting…

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## [Error printing custom types](https://discourse.julialang.org/t/error-printing-custom-types/33414)

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**Author:** [@RodolfoFigueroa](https://discourse.julialang.org/u/RodolfoFigueroa)\
**Replies:** 1\
**Last updated:** [January 15, 2020, 9:01pm UTC](https://discourse.julialang.org/t/error-printing-custom-types/33414 "2020-01-15T21:01:39Z")

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If we define a new show method for a custom class and then create a variable with said class, Juno will keep printing the variable to the REPL. Here is a MWE: import Base.show mutable struct foo bar end function sho…

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## [Understand how to pass the correct input(s), e.g. for atan (atan2)](https://discourse.julialang.org/t/understand-how-to-pass-the-correct-input-s-e-g-for-atan-atan2/33410)

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**Author:** [@Pablo\_J\_Gonzalez](https://discourse.julialang.org/u/Pablo_J_Gonzalez)\
**Replies:** 2\
**Last updated:** [January 15, 2020, 8:33pm UTC](https://discourse.julialang.org/t/understand-how-to-pass-the-correct-input-s-e-g-for-atan-atan2/33410 "2020-01-15T20:33:15Z")

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Hi there, I am newbie to Julia. I am learning Julia, and so I want to create a simple function to convert a set of coordinates from cartesian to polar, and backwards. This is a trivial task, but I am stuck on the correc…

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## [HPC Wire article](https://discourse.julialang.org/t/hpc-wire-article/33404)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 2\
**Last updated:** [January 15, 2020, 6:24pm UTC](https://discourse.julialang.org/t/hpc-wire-article/33404 "2020-01-15T18:24:55Z")

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EDIT: Sorry, it appears this info has already been posted (HPCwire - Julia Programming’s Dramatic Rise in HPC and Elsewhere).

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## [Error in building julia](https://discourse.julialang.org/t/error-in-building-julia/33272)

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**Author:** [@buzz](https://discourse.julialang.org/u/buzz)\
**Replies:** 6\
**Last updated:** [January 15, 2020, 6:13pm UTC](https://discourse.julialang.org/t/error-in-building-julia/33272 "2020-01-15T18:13:33Z")

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i get this error when I try to make /home/balaji/julia/deps/llvm.mk:575: \*\*\* Attempting to use gcc4 LLVM tarball, but compiling with cxx11 string ABI; set “CXXFLAGS=-D\_GLIBCXX\_USE\_CXX11\_ABI=0” to avoid linker errors. S…

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## [Alan Edelman's talk at Boeing colloquium](https://discourse.julialang.org/t/alan-edelmans-talk-at-boeing-colloquium/33403)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 0\
**Last updated:** [January 15, 2020, 4:30pm UTC](https://discourse.julialang.org/t/alan-edelmans-talk-at-boeing-colloquium/33403 "2020-01-15T16:30:52Z")

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## [LaTeX amsmath in Documenter](https://discourse.julialang.org/t/latex-amsmath-in-documenter/33356)

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**Author:** [@squirrel](https://discourse.julialang.org/u/squirrel)\
**Replies:** 2\
**Last updated:** [January 15, 2020, 3:07pm UTC](https://discourse.julialang.org/t/latex-amsmath-in-documenter/33356 "2020-01-15T15:07:34Z")

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I’d like to make a matrix with LaTeX’s amsmath package in Documenter. I found this bit on MkDocs and MathJax, but I’m not sure how to manipulate python. Could anyone help me out or direct me to a more in-depth tutorial? …

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## [Pkg instantiate a package](https://discourse.julialang.org/t/pkg-instantiate-a-package/33396)

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**Author:** [@schlichtanders](https://discourse.julialang.org/u/schlichtanders)\
**Replies:** 5\
**Last updated:** [January 15, 2020, 3:07pm UTC](https://discourse.julialang.org/t/pkg-instantiate-a-package/33396 "2020-01-15T15:07:24Z")

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Hi, I currently develop interdependent Julia packages and look for an easy way to share my work to others. The packages are all un-registered yet. What I understood so far to realize this: define dependencies by refe…

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## [HPCwire - Julia Programming’s Dramatic Rise in HPC and Elsewhere](https://discourse.julialang.org/t/hpcwire-julia-programming-s-dramatic-rise-in-hpc-and-elsewhere/33397)

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**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 0\
**Last updated:** [January 15, 2020, 2:00pm UTC](https://discourse.julialang.org/t/hpcwire-julia-programming-s-dramatic-rise-in-hpc-and-elsewhere/33397 "2020-01-15T14:00:56Z")

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Eight years ago a crack programming unit was sent to prison by a military court for a branch they didn’t commit. These men promptly escaped from a maximum-security stockade to the Cambridge, Massachusets underground. T…

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## [Weird errors in Juno](https://discourse.julialang.org/t/weird-errors-in-juno/33379)

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**Author:** [@nxtruong](https://discourse.julialang.org/u/nxtruong)\
**Replies:** 3\
**Last updated:** [January 15, 2020, 12:23pm UTC](https://discourse.julialang.org/t/weird-errors-in-juno/33379 "2020-01-15T12:23:53Z")

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I’m using the current version of Juno (uber-juno 0.3.0) on Atom 1.42.0, with Julia 1.3.0 (Julia 1.3.1 has the same issues, just slightly different error messages). I’ve been seeing weird errors that only happen in Juno, n…

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## [Difficulty defining \`==\` for a custom type](https://discourse.julialang.org/t/difficulty-defining-for-a-custom-type/33390)

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**Author:** [@ColinCaine](https://discourse.julialang.org/u/ColinCaine)\
**Replies:** 1\
**Last updated:** [January 15, 2020, 11:17am UTC](https://discourse.julialang.org/t/difficulty-defining-for-a-custom-type/33390 "2020-01-15T11:17:17Z")

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I’ve defined two == methods for a custom type, and they work, but I was a bit surprised that: There is not a symmetry fallback for == as there is for promote\_rule There is not a promotion fallback for == The code belo…

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## [GR.jl: Change backgroundcolor of savefig() image](https://discourse.julialang.org/t/gr-jl-change-backgroundcolor-of-savefig-image/33382)

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**Author:** [@al314](https://discourse.julialang.org/u/al314)\
**Replies:** 2\
**Last updated:** [January 15, 2020, 10:25am UTC](https://discourse.julialang.org/t/gr-jl-change-backgroundcolor-of-savefig-image/33382 "2020-01-15T10:25:20Z")

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Hi all, The script using GR plot(randn(199)) savefig("./test.PNG") produces a PNG picture with a transparent background. How to fix this and make it for example white? Thanks.

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## [\[ANN\] SnoopCompile 1.2 - Package Precompilation](https://discourse.julialang.org/t/ann-snoopcompile-1-2-package-precompilation/33359)

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**Author:** [@Amin\_Yahyaabadi](https://discourse.julialang.org/u/Amin_Yahyaabadi)\
**Replies:** 2\
**Last updated:** [January 15, 2020, 9:58am UTC](https://discourse.julialang.org/t/ann-snoopcompile-1-2-package-precompilation/33359 "2020-01-15T09:58:35Z")

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I am happy to announce that SnoopCompile 1.2 now has a GitHub Actions Bot, and it introduces @snoopiBot and @snoopiBench macros. You can use this feature to automatically create precompilation signatures for your packa…

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## [Managing packages for multiple julia versions](https://discourse.julialang.org/t/managing-packages-for-multiple-julia-versions/33352)

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**Author:** [@BrucePBon](https://discourse.julialang.org/u/BrucePBon)\
**Replies:** 6\
**Last updated:** [January 15, 2020, 9:27am UTC](https://discourse.julialang.org/t/managing-packages-for-multiple-julia-versions/33352 "2020-01-15T09:27:40Z")

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Hi there, I was working with Julia 1.0 in the past and now want to move my code to Julia 1.3.1. So I have downloaded the Julia 1.3.1 binaries and set a symlink to the new julia executable. When I try “using IJulia” from…

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## [Barycentric interpolation formula with interval arithmetic](https://discourse.julialang.org/t/barycentric-interpolation-formula-with-interval-arithmetic/33380)

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**Author:** [@ArjunNarayanan](https://discourse.julialang.org/u/ArjunNarayanan)\
**Replies:** 0\
**Last updated:** [January 15, 2020, 6:07am UTC](https://discourse.julialang.org/t/barycentric-interpolation-formula-with-interval-arithmetic/33380 "2020-01-15T06:07:16Z")

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Barycentric interpolation is a numerically stable algorithm to evaluate Lagrange interpolating polynomials. An implementation in Julia is available at BarycentricInterpolation.jl. The procedure takes as input a set of n…

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## [JuliaDB, handling and transforming dates](https://discourse.julialang.org/t/juliadb-handling-and-transforming-dates/33346)

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**Author:** [@rna1990](https://discourse.julialang.org/u/rna1990)\
**Replies:** 5\
**Last updated:** [January 14, 2020, 10:27pm UTC](https://discourse.julialang.org/t/juliadb-handling-and-transforming-dates/33346 "2020-01-14T22:27:45Z")

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Dear fellow julians, Quick question: let’s say I have an IndexedTable object with a column :Date which contains strings in format “01-JUL-19”. What’s the best way to transform the column into proper Date type? Thanks i…

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## [Commit Artifacts.toml?](https://discourse.julialang.org/t/commit-artifacts-toml/33366)

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**Author:** [@DrChainsaw](https://discourse.julialang.org/u/DrChainsaw)\
**Replies:** 0\
**Last updated:** [January 14, 2020, 10:12pm UTC](https://discourse.julialang.org/t/commit-artifacts-toml/33366 "2020-01-14T22:12:20Z")

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Hi, I’m using artifacts to grab some testdata files using the method from the “working with artifacts” section in this blog. Overall it is a pleasure to use it so big kudos to the developers! I do have some questions …

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## [Implementation of Norvigs spellchecker (Code critique + performance help)](https://discourse.julialang.org/t/implementation-of-norvigs-spellchecker-code-critique-performance-help/33038)

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**Author:** [@dunefox](https://discourse.julialang.org/u/dunefox)\
**Replies:** 21\
**Last updated:** [January 14, 2020, 8:21pm UTC](https://discourse.julialang.org/t/implementation-of-norvigs-spellchecker-code-critique-performance-help/33038 "2020-01-14T20:21:34Z")

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I know python relatively well and wanted to learn Julia, so for my first steps I tried to implement Norvigs spellchecker (How to Write a Spelling Corrector). It’s working as intended and I kept it as close as possible bu…

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## [Why not make + and sum() operators between Booleans act as bitwise operators?](https://discourse.julialang.org/t/why-not-make-and-sum-operators-between-booleans-act-as-bitwise-operators/33350)

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**Author:** [@Emre\_Acarturk](https://discourse.julialang.org/u/Emre_Acarturk)\
**Replies:** 5\
**Last updated:** [January 14, 2020, 7:34pm UTC](https://discourse.julialang.org/t/why-not-make-and-sum-operators-between-booleans-act-as-bitwise-operators/33350 "2020-01-14T19:34:45Z")

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I feel like this change wouldn’t affect Julia in general, but AND and OR operation between Boolean variables are usually denoted as addition and multiplication and result in a Boolean. In its current implementation, sum(…

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