# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1625

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

**Page:** 1626

---

## [JSON3 Package: ArgumentError: invalid JSON at byte .... : InvalidChar?](https://discourse.julialang.org/t/json3-package-argumenterror-invalid-json-at-byte-invalidchar/46933)

<div class="topic-metadata">

**Author:** [@DataPsycho](https://discourse.julialang.org/u/DataPsycho)\
**Replies:** 1\
**Last updated:** [September 21, 2020, 4:38am UTC](https://discourse.julialang.org/t/json3-package-argumenterror-invalid-json-at-byte-invalidchar/46933 "2020-09-21T04:38:20Z")

</div>

Suppose I have two Structs one for Tweet and another for Author of the tweet as follows: struct User id::Union{Int64, Nothing} id\_str::Union{String, Nothing} created\_at::Union{String, Nothing} name::Unio…

---

## [JuMP 0.21.5 released](https://discourse.julialang.org/t/jump-0-21-5-released/46976)

<div class="topic-metadata">

**Author:** [@odow](https://discourse.julialang.org/u/odow)\
**Replies:** 0\
**Last updated:** [September 21, 2020, 2:40am UTC](https://discourse.julialang.org/t/jump-0-21-5-released/46976 "2020-09-21T02:40:29Z")

</div>

Dear all, We are happy to announce the joint release of JuMP 0.21.5 and MathOptInterface 0.9.17! These releases are a mix of new features and some much needed performance optimizations. This should be a non-breaking rel…

---

## [Different Float64 sum on different architectures](https://discourse.julialang.org/t/different-float64-sum-on-different-architectures/46949)

<div class="topic-metadata">

**Author:** [@greg\_plowman](https://discourse.julialang.org/u/greg_plowman)\
**Replies:** 9\
**Last updated:** [September 20, 2020, 9:31pm UTC](https://discourse.julialang.org/t/different-float64-sum-on-different-architectures/46949 "2020-09-20T21:31:31Z")

</div>

I sometimes get different results for summing a vector of Float64 numbers on different Windows machines. The vectors are identical, so it seems sum can produce different results across hardware architectures (even if os …

---

## [How does BusinessDays.jl work?](https://discourse.julialang.org/t/how-does-businessdays-jl-work/46968)

<div class="topic-metadata">

**Author:** [@Derek\_Vetsch](https://discourse.julialang.org/u/Derek_Vetsch)\
**Replies:** 1\
**Last updated:** [September 20, 2020, 9:07pm UTC](https://discourse.julialang.org/t/how-does-businessdays-jl-work/46968 "2020-09-20T21:07:16Z")

</div>

I see in the BusinessDays docs that the package achieves its performance by using a cache. However, I don’t understand what a cache means in this context, and how does using one create superior performance to something l…

---

## [Benchmarking inside a module](https://discourse.julialang.org/t/benchmarking-inside-a-module/46967)

<div class="topic-metadata">

**Author:** [@pauljurczak](https://discourse.julialang.org/u/pauljurczak)\
**Replies:** 1\
**Last updated:** [September 20, 2020, 8:46pm UTC](https://discourse.julialang.org/t/benchmarking-inside-a-module/46967 "2020-09-20T20:46:41Z")

</div>

I’m trying to get benchmark results of a function inside a module displayed in REPL. Here is an example: module Ex9 using BenchmarkTools a = rand(100, 100) function foo(a) m = maximum(a) map(x -\> x\<0 ? 0 : x\<0.8m …

---

## [ANN: MaxMinFilters.jl - fast streaming maximum / minimum within moving window](https://discourse.julialang.org/t/ann-maxminfilters-jl-fast-streaming-maximum-minimum-within-moving-window/30151)

<div class="topic-metadata">

**Author:** [@sairus7](https://discourse.julialang.org/u/sairus7)\
**Replies:** 23\
**Last updated:** [September 20, 2020, 8:44pm UTC](https://discourse.julialang.org/t/ann-maxminfilters-jl-fast-streaming-maximum-minimum-within-moving-window/30151 "2020-09-20T20:44:31Z")

</div>

A detailed description at: Here I’d like to ask some questions to the Julia Community: Should this package become a part of DSP.jl? There are several packages in Julia with overlapping functionality: RollingFunctions…

---

## [With new Julia Client update, atom not working](https://discourse.julialang.org/t/with-new-julia-client-update-atom-not-working/46964)

<div class="topic-metadata">

**Author:** [@Guillermo\_Sepulveda](https://discourse.julialang.org/u/Guillermo_Sepulveda)\
**Replies:** 1\
**Last updated:** [September 20, 2020, 7:47pm UTC](https://discourse.julialang.org/t/with-new-julia-client-update-atom-not-working/46964 "2020-09-20T19:47:08Z")

</div>

I was working in Julia and it was an update for Julia Client, once it finish updating it says restart so i did, and when atom open again the left panel was gone and doesn´t appear “Press enter to start Julia”, so now i c…

---

## [Hacktoberfest 2020 x The Julia Language](https://discourse.julialang.org/t/hacktoberfest-2020-x-the-julia-language/46927)

<div class="topic-metadata">

**Author:** [@logankilpatrick](https://discourse.julialang.org/u/logankilpatrick)\
**Replies:** 5\
**Last updated:** [September 20, 2020, 5:50pm UTC](https://discourse.julialang.org/t/hacktoberfest-2020-x-the-julia-language/46927 "2020-09-20T17:50:10Z")

</div>

Hey all, Hacktoberfest 2020 is right around the corner. If you are a project maintainer/contributor, it would be awesome to tag a few beginner issues with the “hacktoberfest” tag on GitHub so we can attract some new fol…

---

## [throw(ErrorException(...)) vs. @error](https://discourse.julialang.org/t/throw-errorexception-vs-error/46955)

<div class="topic-metadata">

**Author:** [@bobcassels](https://discourse.julialang.org/u/bobcassels)\
**Replies:** 3\
**Last updated:** [September 20, 2020, 5:45pm UTC](https://discourse.julialang.org/t/throw-errorexception-vs-error/46955 "2020-09-20T17:45:15Z")

</div>

For development / debugging, I’ve been using throw(ErrorException(...)), and @assert. As this code moves to production, where it will be in a batch job running in “the cloud”, I’d like to have such errors logged. What’…

---

## [Query.jl @groupby How to specify the key selector properly?](https://discourse.julialang.org/t/query-jl-groupby-how-to-specify-the-key-selector-properly/46929)

<div class="topic-metadata">

**Author:** [@kai](https://discourse.julialang.org/u/kai)\
**Replies:** 1\
**Last updated:** [September 20, 2020, 5:19pm UTC](https://discourse.julialang.org/t/query-jl-groupby-how-to-specify-the-key-selector-properly/46929 "2020-09-20T17:19:33Z")

</div>

Hello, I wonder what is the proper way to use the @groupby function from Query.jl when the key selector is a variable of type Symbol? Example: using DataFrames, Query df = DataFrame(name=\["John", "Sally", "Kirk"\], age=…

---

## [Running package tests really slow](https://discourse.julialang.org/t/running-package-tests-really-slow/46587)

<div class="topic-metadata">

**Author:** [@floswald](https://discourse.julialang.org/u/floswald)\
**Replies:** 12\
**Last updated:** [September 20, 2020, 2:43pm UTC](https://discourse.julialang.org/t/running-package-tests-really-slow/46587 "2020-09-20T14:43:01Z")

</div>

I’m a bit surprised that running unit tests for a simple trial package takes a lot fo time. I am wondering what I’m doing wrong. running \] test in this example takes 36 seconds. Note that there is no computation involv…

---

## [Plots.PlotlyJSBackend () is displayed as GR ()](https://discourse.julialang.org/t/plots-plotlyjsbackend-is-displayed-as-gr/46902)

<div class="topic-metadata">

**Author:** [@HerAdri](https://discourse.julialang.org/u/HerAdri)\
**Replies:** 20\
**Last updated:** [September 20, 2020, 2:30pm UTC](https://discourse.julialang.org/t/plots-plotlyjsbackend-is-displayed-as-gr/46902 "2020-09-20T14:30:43Z")

</div>

When running the following lines of code I receive the same graphic, and the last lines are expected to deliver an interactive graphic. Julia\>versioninfo() Julia Version 1.5.1 Commit 697e782ab8 (2020-08-25 20:08 UTC) Pl…

---

## [Applying group selection conditions using groupeddataframes](https://discourse.julialang.org/t/applying-group-selection-conditions-using-groupeddataframes/46060)

<div class="topic-metadata">

**Author:** [@jo-fleck](https://discourse.julialang.org/u/jo-fleck)\
**Replies:** 21\
**Last updated:** [September 20, 2020, 11:40am UTC](https://discourse.julialang.org/t/applying-group-selection-conditions-using-groupeddataframes/46060 "2020-09-20T11:40:48Z")

</div>

I need to select groups of observations from a large dataframe (about 2.9 mio rows) using a number of conditions which apply to different observations in each group (so I cannot select on individual rows only). Using a …

---

## [Random seeds in parallel computing](https://discourse.julialang.org/t/random-seeds-in-parallel-computing/46899)

<div class="topic-metadata">

**Author:** [@AAL](https://discourse.julialang.org/u/AAL)\
**Replies:** 5\
**Last updated:** [September 20, 2020, 8:57am UTC](https://discourse.julialang.org/t/random-seeds-in-parallel-computing/46899 "2020-09-20T08:57:13Z")

</div>

I am trying to run a simulation in parallel and I am having trouble understanding how random numbers are generated in this setting. It seems like I can generate pseudorandom numbers in several cores with the same random …

---

## [Plots: bars side by side](https://discourse.julialang.org/t/plots-bars-side-by-side/6655)

<div class="topic-metadata">

**Author:** [@kaslusimoes](https://discourse.julialang.org/u/kaslusimoes)\
**Replies:** 14\
**Last updated:** [September 20, 2020, 9:46am UTC](https://discourse.julialang.org/t/plots-bars-side-by-side/6655 "2020-09-20T09:46:58Z")

</div>

Hi there, I’m using Plots.jl (with PyPlot as the backend) and trying to plot some bars side by side, as in the following example from matplotlib: http://matplotlib.org/examples/api/barchart\_demo.html (figure below) L…

---

## [Fall in GitHub code frequency](https://discourse.julialang.org/t/fall-in-github-code-frequency/46941)

<div class="topic-metadata">

**Author:** [@rakesh4real](https://discourse.julialang.org/u/rakesh4real)\
**Replies:** 7\
**Last updated:** [September 20, 2020, 1:47am UTC](https://discourse.julialang.org/t/fall-in-github-code-frequency/46941 "2020-09-20T01:47:30Z")

</div>

Hi, I work extensively in deep learning projects and had known Julia for quite a while. Today, I was skimming through code frequency graph and the fall really concerned me. Can I know if is something that I should worry…

---

## [SciML is now a NumFOCUS Sponsored Project!](https://discourse.julialang.org/t/sciml-is-now-a-numfocus-sponsored-project/46892)

<div class="topic-metadata">

**Author:** [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Replies:** 4\
**Last updated:** [September 20, 2020, 12:04am UTC](https://discourse.julialang.org/t/sciml-is-now-a-numfocus-sponsored-project/46892 "2020-09-20T00:04:48Z")

</div>

Hello everyone, We are pleased to announce that SciML is now a NumFOCUS Sponsored Project! We thank the Julia community which has been instrumental in helping grow to this point. The purpose of the SciML organization…

---

## [SQLite.jl execute with "pragma" not working](https://discourse.julialang.org/t/sqlite-jl-execute-with-pragma-not-working/46935)

<div class="topic-metadata">

**Author:** [@andrey2185](https://discourse.julialang.org/u/andrey2185)\
**Replies:** 1\
**Last updated:** [September 19, 2020, 10:04pm UTC](https://discourse.julialang.org/t/sqlite-jl-execute-with-pragma-not-working/46935 "2020-09-19T22:04:12Z")

</div>

Hello, why this not working? I do using SQLite db = SQLite.DB("SQLite\_test.db") SQLite.execute(db, "PRAGMA count\_changes=true;") but then count\_changes=false in my database

---

## [Stanford Alum Seeking Engineering or Software Role :)](https://discourse.julialang.org/t/stanford-alum-seeking-engineering-or-software-role/46936)

<div class="topic-metadata">

**Author:** [@pxshen](https://discourse.julialang.org/u/pxshen)\
**Replies:** 0\
**Last updated:** [September 19, 2020, 8:50pm UTC](https://discourse.julialang.org/t/stanford-alum-seeking-engineering-or-software-role/46936 "2020-09-19T20:50:28Z")

</div>

Hello! I’m a Stanford alum (MS Electrical Engineering, BS Math) seeking roles in machine learning, reinforcement learning, signal processing, control systems, data science, computational modeling… I love Julia and am al…

---

## [\[ANN\] JSON3.jl - Yet another JSON package for Julia](https://discourse.julialang.org/t/ann-json3-jl-yet-another-json-package-for-julia/25625)

<div class="topic-metadata">

**Author:** [@quinnj](https://discourse.julialang.org/u/quinnj)\
**Replies:** 23\
**Last updated:** [September 19, 2020, 8:38pm UTC](https://discourse.julialang.org/t/ann-json3-jl-yet-another-json-package-for-julia/25625 "2020-09-19T20:38:00Z")

</div>

I’m pleased to share the registration of a new package, JSON3.jl, in the General registry, available immediately. Let’s cut right to the chase and answer the elephant questions in the proverbial discourse room: why do w…

---

## [How do I make multiple figures in PGFPlotsX and add a table?](https://discourse.julialang.org/t/how-do-i-make-multiple-figures-in-pgfplotsx-and-add-a-table/46904)

<div class="topic-metadata">

**Author:** [@Ahmed\_Salih](https://discourse.julialang.org/u/Ahmed_Salih)\
**Replies:** 9\
**Last updated:** [September 19, 2020, 7:56pm UTC](https://discourse.julialang.org/t/how-do-i-make-multiple-figures-in-pgfplotsx-and-add-a-table/46904 "2020-09-19T19:56:41Z")

</div>

Hello! If I wanted to construct something like this: As far as for the code I see he is using multiple “\\begin{axis}”, but I don’t know if that is possible in PGFPlotsX. I had a look at the gallery here: https://k…

---

## [Slow Cholesky factorization for sparse matrices?](https://discourse.julialang.org/t/slow-cholesky-factorization-for-sparse-matrices/46909)

<div class="topic-metadata">

**Author:** [@Albert\_de\_montserrat](https://discourse.julialang.org/u/Albert_de_montserrat)\
**Replies:** 6\
**Last updated:** [September 19, 2020, 7:45pm UTC](https://discourse.julialang.org/t/slow-cholesky-factorization-for-sparse-matrices/46909 "2020-09-19T19:45:05Z")

</div>

I am trying to compare Julia’s Cholesky factorization against MATLAB for sparse matrices, and Julia seems almost 2 times slower than MATLAB. Julia: using SparseArrays,BenchmarkTools, LinearAlgebra n = Int(5e3) A = rand…

---

## [Disabling emoji suggestion?](https://discourse.julialang.org/t/disabling-emoji-suggestion/46928)

<div class="topic-metadata">

**Author:** [@Mehrdad\_Anvar](https://discourse.julialang.org/u/Mehrdad_Anvar)\
**Replies:** 0\
**Last updated:** [September 19, 2020, 7:09pm UTC](https://discourse.julialang.org/t/disabling-emoji-suggestion/46928 "2020-09-19T19:09:22Z")

</div>

Does anyone know how to disable emoji suggestion in Atom while typing code? I am trying to get autocompletion for a file path and atom constantly suggest emojis when I use double backtikcs

---

## [Memoize Pkg? Bad use of Metaprogramming?](https://discourse.julialang.org/t/memoize-pkg-bad-use-of-metaprogramming/46874)

<div class="topic-metadata">

**Author:** [@anon92994695](https://discourse.julialang.org/u/anon92994695)\
**Replies:** 14\
**Last updated:** [September 19, 2020, 5:21pm UTC](https://discourse.julialang.org/t/memoize-pkg-bad-use-of-metaprogramming/46874 "2020-09-19T17:21:19Z")

</div>

Been doing some long-running computations. I mean … long. So I am doing the obvious thing, storing results to disk along the way. For reproducibility reasons I’d like to be able to memoize lots of intermediate results al…

---

## [Improving Barnes-Hut n-body simulation performance](https://discourse.julialang.org/t/improving-barnes-hut-n-body-simulation-performance/20864)

<div class="topic-metadata">

**Author:** [@novoselrok](https://discourse.julialang.org/u/novoselrok)\
**Replies:** 14\
**Last updated:** [September 19, 2020, 5:03pm UTC](https://discourse.julialang.org/t/improving-barnes-hut-n-body-simulation-performance/20864 "2020-09-19T17:03:17Z")

</div>

Hi. I’m writing a Barnes-Hut simulator in Julia but I’m experiencing a slowdown compared to the C version. For 80k bodies: C - 25 seconds Julia - 35 seconds As expected it spends 99.9% time in the compute\_force func…

---

## [Its possible to use all cores or parallel cores to do some project/calculations?](https://discourse.julialang.org/t/its-possible-to-use-all-cores-or-parallel-cores-to-do-some-project-calculations/46639)

<div class="topic-metadata">

**Author:** [@Lucas\_Pollito](https://discourse.julialang.org/u/Lucas_Pollito)\
**Replies:** 41\
**Last updated:** [September 19, 2020, 4:05pm UTC](https://discourse.julialang.org/t/its-possible-to-use-all-cores-or-parallel-cores-to-do-some-project-calculations/46639 "2020-09-19T16:05:58Z")

</div>

I have three different and independent task/calculation to do. function interpQa() ag = 0.01:0.05:3 aσ = 0.03 : 0.025 : 0.63 if PrimeiraVez mQ = \[Q(g,sigma) for g in ag, sigma in aσ\] w…

---

## [How to get the rendered window size when directly using PlotlyJS](https://discourse.julialang.org/t/how-to-get-the-rendered-window-size-when-directly-using-plotlyjs/26610)

<div class="topic-metadata">

**Author:** [@kobussch](https://discourse.julialang.org/u/kobussch)\
**Replies:** 1\
**Last updated:** [September 19, 2020, 3:57pm UTC](https://discourse.julialang.org/t/how-to-get-the-rendered-window-size-when-directly-using-plotlyjs/26610 "2020-09-19T15:57:37Z")

</div>

I am using Spencer Lyon’s PlotlyJS package as basis for an interactive data visualization tool. It is fantastic, but I am stuck on a particular issue: how to get the rendered size of the plot area (in pixels) when it is …

---

## [Managing GitHub influx of notification emails](https://discourse.julialang.org/t/managing-github-influx-of-notification-emails/46737)

<div class="topic-metadata">

**Author:** [@mohamed82008](https://discourse.julialang.org/u/mohamed82008)\
**Replies:** 4\
**Last updated:** [September 19, 2020, 3:31pm UTC](https://discourse.julialang.org/t/managing-github-influx-of-notification-emails/46737 "2020-09-19T15:31:13Z")

</div>

I suspect many people here involved in many GitHub projects or following many people on GitHub receive 10s or 100s of emails every day regarding various things happening on GitHub. Some emails are more important than oth…

---

## [Most elegant way to fill an Array inside for loop?](https://discourse.julialang.org/t/most-elegant-way-to-fill-an-array-inside-for-loop/46914)

<div class="topic-metadata">

**Author:** [@JohannesUl](https://discourse.julialang.org/u/JohannesUl)\
**Replies:** 2\
**Last updated:** [September 19, 2020, 2:30pm UTC](https://discourse.julialang.org/t/most-elegant-way-to-fill-an-array-inside-for-loop/46914 "2020-09-19T14:30:15Z")

</div>

Hi, I am kind of new to the Julia language. I am looking for the most elegant way to fill an Array like in the following code section? (which does not work) dr = Date(2020,9,12):Day(1):Date(2020,9,18) openingHours = Ar…

---

## [@NamedTuple fails](https://discourse.julialang.org/t/namedtuple-fails/46916)

<div class="topic-metadata">

**Author:** [@Inbar\_Maimon](https://discourse.julialang.org/u/Inbar_Maimon)\
**Replies:** 2\
**Last updated:** [September 19, 2020, 2:27pm UTC](https://discourse.julialang.org/t/namedtuple-fails/46916 "2020-09-19T14:27:06Z")

</div>

Hi there, I copied this line: @NamedTuple{a::Int, b::String} from the manual to the REPL and instead of the expected NamedTuple{(:a, :b),Tuple{Int64,String}} it returned an error: ERROR: syntax: invalid macro usage…

[Previous page](https://discourse.julialang.org/latest.md?page=1624)

[Next page](https://discourse.julialang.org/latest.md?page=1626)