# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1145

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

**Page:** 1146

---

## [Propositions for re-cutting videos from JuliaCon 2019](https://discourse.julialang.org/t/propositions-for-re-cutting-videos-from-juliacon-2019/74988)

<div class="topic-metadata">

**Author:** [@KZiemian](https://discourse.julialang.org/u/KZiemian)\
**Replies:** 5\
**Last updated:** [January 21, 2022, 10:41pm UTC](https://discourse.julialang.org/t/propositions-for-re-cutting-videos-from-juliacon-2019/74988 "2022-01-21T22:41:30Z")

</div>

Many videos from JuliaCon 2019 have quite long openings, when we can see only poster of this JuliaCon or watch preparation for the talk. Also they can have similarly long endings. Below you can see information about 20 f…

---

## [Matrix multiplication is slower when multithreading in Julia](https://discourse.julialang.org/t/matrix-multiplication-is-slower-when-multithreading-in-julia/56227)

<div class="topic-metadata">

**Author:** [@pablof300](https://discourse.julialang.org/u/pablof300)\
**Replies:** 13\
**Last updated:** [January 21, 2022, 10:26pm UTC](https://discourse.julialang.org/t/matrix-multiplication-is-slower-when-multithreading-in-julia/56227 "2022-01-21T22:26:46Z")

</div>

I am working with big matrices (size of 30k rows and ~100 columns). I am doing some matrix multiplication and the process would take around 20 seconds. This is my code: @time begin result = -1 data =…

---

## [LegacyStrings.UTF8String](https://discourse.julialang.org/t/legacystrings-utf8string/75010)

<div class="topic-metadata">

**Author:** [@jzr](https://discourse.julialang.org/u/jzr)\
**Replies:** 1\
**Last updated:** [January 21, 2022, 9:53pm UTC](https://discourse.julialang.org/t/legacystrings-utf8string/75010 "2022-01-21T21:53:32Z")

</div>

Core.String is a utf8 string written in C. What is the difference between it and LegacyStrings.UTF8String?

---

## [Splat ComponentArray into keyword arguments](https://discourse.julialang.org/t/splat-componentarray-into-keyword-arguments/75003)

<div class="topic-metadata">

**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 4\
**Last updated:** [January 21, 2022, 9:03pm UTC](https://discourse.julialang.org/t/splat-componentarray-into-keyword-arguments/75003 "2022-01-21T21:03:53Z")

</div>

Hi all, I have a situation in which “splatting” a ComponentArray into keyword arguments would be useful. Unfortunately, it is not currently possible. I was wondering whether it would be possible in principle? Could I ad…

---

## [How run examples in AstronNbodySim](https://discourse.julialang.org/t/how-run-examples-in-astronnbodysim/74960)

<div class="topic-metadata">

**Author:** [@murrayE](https://discourse.julialang.org/u/murrayE)\
**Replies:** 2\
**Last updated:** [January 21, 2022, 8:59pm UTC](https://discourse.julialang.org/t/how-run-examples-in-astronnbodysim/74960 "2022-01-21T20:59:20Z")

</div>

From the REPL, I installed the AstroNbodySim package by \]add AstroNbodySim. Next, inside my usual ~/Documents/julia directory for projects, I used \] generate Nbody and then \] activate Nbody. I want to run some of the e…

---

## [Bug with Winston 0.15.2 and julia 1.7.1?](https://discourse.julialang.org/t/bug-with-winston-0-15-2-and-julia-1-7-1/75005)

<div class="topic-metadata">

**Author:** [@harven](https://discourse.julialang.org/u/harven)\
**Replies:** 0\
**Last updated:** [January 21, 2022, 8:44pm UTC](https://discourse.julialang.org/t/bug-with-winston-0-15-2-and-julia-1-7-1/75005 "2022-01-21T20:44:39Z")

</div>

I have upgraded to julia 1.7.1 and I encounter a weird error perhaps related to the Winston library. julia\> using Winston julia\> flatten6(A) = \[\[isa(x,Array) ? flatten6(x) : x for x in A\]...;\] flatten6 (generi…

---

## [Transform! to destructure NamedTuple into columns](https://discourse.julialang.org/t/transform-to-destructure-namedtuple-into-columns/74991)

<div class="topic-metadata">

**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 7\
**Last updated:** [January 21, 2022, 5:15pm UTC](https://discourse.julialang.org/t/transform-to-destructure-namedtuple-into-columns/74991 "2022-01-21T17:15:42Z")

</div>

Hi all, I would like to destructure a DataFrame with NamedTuples into separate columns, using the keys as column names. For a similar problem with an array, I used something like transform!(df, :col =\> :identity =\> new\_…

---

## [Adding a sysimage to a julia script - Package Complier](https://discourse.julialang.org/t/adding-a-sysimage-to-a-julia-script-package-complier/74994)

<div class="topic-metadata">

**Author:** [@maulik.bhatt](https://discourse.julialang.org/u/maulik.bhatt)\
**Replies:** 0\
**Last updated:** [January 21, 2022, 4:56pm UTC](https://discourse.julialang.org/t/adding-a-sysimage-to-a-julia-script-package-complier/74994 "2022-01-21T16:56:41Z")

</div>

I have a Julia script which uses several packages and runs several functions from them. This Julia script takes a lot of time every time I run it because every package is precompiled in julia every time I run that script…

---

## [Error deploying in AWS Lambda and Google Cloud Run](https://discourse.julialang.org/t/error-deploying-in-aws-lambda-and-google-cloud-run/60959)

<div class="topic-metadata">

**Author:** [@pedroferraz](https://discourse.julialang.org/u/pedroferraz)\
**Replies:** 5\
**Last updated:** [January 21, 2022, 4:24pm UTC](https://discourse.julialang.org/t/error-deploying-in-aws-lambda-and-google-cloud-run/60959 "2022-01-21T16:24:08Z")

</div>

I am trying to deploy a simple microservice in a docker container with a HTTP server that uses JuMP in AWS Lambda or Google Cloud Run. I based my application’s code in Jacob Quinn’s example from JuliaCon 2020 (JuliaCon 2…

---

## [Does composite algorithm work with Sundials? I get an error](https://discourse.julialang.org/t/does-composite-algorithm-work-with-sundials-i-get-an-error/74990)

<div class="topic-metadata">

**Author:** [@Shashank](https://discourse.julialang.org/u/Shashank)\
**Replies:** 2\
**Last updated:** [January 21, 2022, 3:35pm UTC](https://discourse.julialang.org/t/does-composite-algorithm-work-with-sundials-i-get-an-error/74990 "2022-01-21T15:35:48Z")

</div>

I am trying to solve a set of differential equations and I want to change the algorithm at a certain point in time. I could do it between Tsit5 and Vern7 as described in Julia documentation (commented line in the code be…

---

## [JLD2: triggering the actual writes to file](https://discourse.julialang.org/t/jld2-triggering-the-actual-writes-to-file/74981)

<div class="topic-metadata">

**Author:** [@Gregstrq](https://discourse.julialang.org/u/Gregstrq)\
**Replies:** 3\
**Last updated:** [January 21, 2022, 3:34pm UTC](https://discourse.julialang.org/t/jld2-triggering-the-actual-writes-to-file/74981 "2022-01-21T15:34:28Z")

</div>

Let’s say I saved a dataset named “dataset” to “file.jld2”: using JLD2, Random jldopen("file.jld2", "w") do fd fd\["dataset"\] = \[randn(100,100) for i=1:100\] end Now, I want to alter one of the entries in the dataset…

---

## [Franklin.pagevar("menu1.md", :title)](https://discourse.julialang.org/t/franklin-pagevar-menu1-md-title/74975)

<div class="topic-metadata">

**Author:** [@paradoxical-rhapsody](https://discourse.julialang.org/u/paradoxical-rhapsody)\
**Replies:** 3\
**Last updated:** [January 21, 2022, 3:24pm UTC](https://discourse.julialang.org/t/franklin-pagevar-menu1-md-title/74975 "2022-01-21T15:24:39Z")

</div>

After initialize a site using newsite("test"), in the interactive environment I ran the statement Franklin.pagevar("menu1.md", :title) It throws the following error msg: julia\> Franklin.pagevar("menu1.md", "title") ER…

---

## [Accumulation in the for loop](https://discourse.julialang.org/t/accumulation-in-the-for-loop/74870)

<div class="topic-metadata">

**Author:** [@xspeng](https://discourse.julialang.org/u/xspeng)\
**Replies:** 17\
**Last updated:** [January 21, 2022, 2:31pm UTC](https://discourse.julialang.org/t/accumulation-in-the-for-loop/74870 "2022-01-21T14:31:09Z")

</div>

My problem can be simply understand by the following case: when I write the following program, I hope that c=a\[1:5\]+b\[1:3\] a=\[1 2 3 4 5\] b=\[1 2 3\] c = 0 for i in 1:5, j in 1:3 c += a\[i\] + b\[j\] end but that is e…

---

## [Expansion of ODE equations](https://discourse.julialang.org/t/expansion-of-ode-equations/74859)

<div class="topic-metadata">

**Author:** [@xspeng](https://discourse.julialang.org/u/xspeng)\
**Replies:** 12\
**Last updated:** [January 21, 2022, 2:29pm UTC](https://discourse.julialang.org/t/expansion-of-ode-equations/74859 "2022-01-21T14:29:35Z")

</div>

New to julia, I have a question about how to expand the equations when solve the ODEs, here is a simple example if the initial program is function Eq(dy, y, p, t) para01, para02 = p dy\[1\] = dot(para01 \* y\[2\], …

---

## [Why Plots.jl produce figures looks not as good as other packages even with pyplot](https://discourse.julialang.org/t/why-plots-jl-produce-figures-looks-not-as-good-as-other-packages-even-with-pyplot/74946)

<div class="topic-metadata">

**Author:** [@Fred\_He](https://discourse.julialang.org/u/Fred_He)\
**Replies:** 28\
**Last updated:** [January 21, 2022, 2:17pm UTC](https://discourse.julialang.org/t/why-plots-jl-produce-figures-looks-not-as-good-as-other-packages-even-with-pyplot/74946 "2022-01-21T14:17:40Z")

</div>

Add in 21.Jan. people are trying to tell me the style can be customized, but no one explains why the default style is not pretty at all. And if you think the default is pretty just say it’s pretty. Don’t tell me that i…

---

## [Get Axis from Scene](https://discourse.julialang.org/t/get-axis-from-scene/74935)

<div class="topic-metadata">

**Author:** [@fbanning](https://discourse.julialang.org/u/fbanning)\
**Replies:** 1\
**Last updated:** [January 21, 2022, 12:45pm UTC](https://discourse.julialang.org/t/get-axis-from-scene/74935 "2022-01-21T12:45:51Z")

</div>

If I have a reference to a scene, how can I get a reference to its corresponding axis? Take the following case: fig = Figure() ax = Axis(fig\[1,1\]) s = ax.scene Now if I only have s , how can I get ax? Intuitively I’v…

---

## [Type parameters are treated differently based on their names](https://discourse.julialang.org/t/type-parameters-are-treated-differently-based-on-their-names/74972)

<div class="topic-metadata">

**Author:** [@Ranlajetech](https://discourse.julialang.org/u/Ranlajetech)\
**Replies:** 6\
**Last updated:** [January 21, 2022, 12:13pm UTC](https://discourse.julialang.org/t/type-parameters-are-treated-differently-based-on-their-names/74972 "2022-01-21T12:13:09Z")

</div>

julia\> Type === Type{T} where T true julia\> Type === Type{S} where S false julia\> Type === Type{t} where t false This is what I got in REPL(Julia v1.7.1, Windows10 64-bit). I got the same result running it as a file. …

---

## [\[SOLVED\] How can I evaluate in Main from a module?](https://discourse.julialang.org/t/solved-how-can-i-evaluate-in-main-from-a-module/74908)

<div class="topic-metadata">

**Author:** [@emmettgb](https://discourse.julialang.org/u/emmettgb)\
**Replies:** 8\
**Last updated:** [January 21, 2022, 10:37am UTC](https://discourse.julialang.org/t/solved-how-can-i-evaluate-in-main-from-a-module/74908 "2022-01-21T10:37:32Z")

</div>

Hello! I am trying to make a macro, @each, which will take each value and compare the falsehood of it to a certain condition. The problem is, while it works fine so long as the macro is globally defined, i.e. in a noteb…

---

## [Background/foreground color of Window, Buttons, etc](https://discourse.julialang.org/t/background-foreground-color-of-window-buttons-etc/74956)

<div class="topic-metadata">

**Author:** [@das](https://discourse.julialang.org/u/das)\
**Replies:** 0\
**Last updated:** [January 20, 2022, 8:32pm UTC](https://discourse.julialang.org/t/background-foreground-color-of-window-buttons-etc/74956 "2022-01-20T20:32:07Z")

</div>

Hi everyone, I can’t figure out how to set the background color of the Window and Button widgets and would be very grateful for some help. I got the text and text background to change using this: saveButton = Button(G…

---

## [NEAT implementation using FLux](https://discourse.julialang.org/t/neat-implementation-using-flux/74931)

<div class="topic-metadata">

**Author:** [@SanAlphaTau](https://discourse.julialang.org/u/SanAlphaTau)\
**Replies:** 2\
**Last updated:** [January 21, 2022, 10:00am UTC](https://discourse.julialang.org/t/neat-implementation-using-flux/74931 "2022-01-21T10:00:10Z")

</div>

Heya, I am trying to implement a simplified version of the NEAT algorithm in julia for a project. I was just wondering what the best way of mapping my genomes into actual code it. Can I build flux models “neuron by neur…

---

## [Objective bound of a model within the callback](https://discourse.julialang.org/t/objective-bound-of-a-model-within-the-callback/74941)

<div class="topic-metadata">

**Author:** [@ahmad88](https://discourse.julialang.org/u/ahmad88)\
**Replies:** 3\
**Last updated:** [January 21, 2022, 9:22am UTC](https://discourse.julialang.org/t/objective-bound-of-a-model-within-the-callback/74941 "2022-01-21T09:22:08Z")

</div>

I have a model where I try to add cuts to it within the callback, I am trying to access the objective bound of the model but it is not possible in the callback with the following error message Error evaluating cec-proce…

---

## [Plots.jl + GR backend: time to plot on windows always 2.3 seconds](https://discourse.julialang.org/t/plots-jl-gr-backend-time-to-plot-on-windows-always-2-3-seconds/74752)

<div class="topic-metadata">

**Author:** [@Olivier\_Merchiers](https://discourse.julialang.org/u/Olivier_Merchiers)\
**Replies:** 3\
**Last updated:** [January 21, 2022, 9:11am UTC](https://discourse.julialang.org/t/plots-jl-gr-backend-time-to-plot-on-windows-always-2-3-seconds/74752 "2022-01-21T09:11:03Z")

</div>

Hello everyone, Not sure if this is normal or not, but when I type in the repl the following: julia\> @time using Plots; @time display(plot(rand(10))) 3.859720 seconds (8.52 M allocations: 590.593 MiB, 7.35% gc time, …

---

## [Makie - Uneven dash distribution](https://discourse.julialang.org/t/makie-uneven-dash-distribution/70100)

<div class="topic-metadata">

**Author:** [@nandoconde](https://discourse.julialang.org/u/nandoconde)\
**Replies:** 5\
**Last updated:** [January 21, 2022, 9:05am UTC](https://discourse.julialang.org/t/makie-uneven-dash-distribution/70100 "2022-01-21T09:05:55Z")

</div>

Hello! I was experimenting with different linewidths for my paper and this happened when the :dash or the :dot linestyles were selected with a high linewidth: Is it a bug? Can it be fixed? Thanks!

---

## [Genie.jl and package compiler](https://discourse.julialang.org/t/genie-jl-and-package-compiler/74849)

<div class="topic-metadata">

**Author:** [@a3pelawi](https://discourse.julialang.org/u/a3pelawi)\
**Replies:** 2\
**Last updated:** [January 21, 2022, 8:24am UTC](https://discourse.julialang.org/t/genie-jl-and-package-compiler/74849 "2022-01-21T08:24:05Z")

</div>

Hello, I’m new in julia, but this is very promising and good. I have make a project with genie.jl. Everything run good. Like run command bin/repl or bin/server, run very good. My question is, how to make it to sytem i…

---

## [Monitoring GPU utilization and memory usage](https://discourse.julialang.org/t/monitoring-gpu-utilization-and-memory-usage/74958)

<div class="topic-metadata">

**Author:** [@johnbb](https://discourse.julialang.org/u/johnbb)\
**Replies:** 2\
**Last updated:** [January 21, 2022, 8:05am UTC](https://discourse.julialang.org/t/monitoring-gpu-utilization-and-memory-usage/74958 "2022-01-21T08:05:25Z")

</div>

While training Flux models, I would like to monitor the (Nvidia) GPU utilization and memory usage. Is there an alternative to dump output from nvidia-smi to a file and read and plot the data in Julia?

---

## [Check the sign of a number](https://discourse.julialang.org/t/check-the-sign-of-a-number/42636)

<div class="topic-metadata">

**Author:** [@Nash](https://discourse.julialang.org/u/Nash)\
**Replies:** 5\
**Last updated:** [July 6, 2020, 9:12pm UTC](https://discourse.julialang.org/t/check-the-sign-of-a-number/42636 "2020-07-06T21:12:34Z")

</div>

Does Julia have a simple way to check the sign of a number? Something like: sign(-4) = -1 sign(4) = 1

---

## [DMG & Build alternative for MacOS](https://discourse.julialang.org/t/dmg-build-alternative-for-macos/74945)

<div class="topic-metadata">

**Author:** [@pojo](https://discourse.julialang.org/u/pojo)\
**Replies:** 3\
**Last updated:** [January 21, 2022, 5:21am UTC](https://discourse.julialang.org/t/dmg-build-alternative-for-macos/74945 "2022-01-21T05:21:36Z")

</div>

Company firewall now blocks all dmg file downloads (and xcode on Macbook) so I can’t install current version of Julia or build from source! Forced to stay with 1.5 as that was the last version I can use with direct dow…

---

## [Understanding Allocations and Views](https://discourse.julialang.org/t/understanding-allocations-and-views/74967)

<div class="topic-metadata">

**Author:** [@TI36XPro](https://discourse.julialang.org/u/TI36XPro)\
**Replies:** 4\
**Last updated:** [January 21, 2022, 4:31am UTC](https://discourse.julialang.org/t/understanding-allocations-and-views/74967 "2022-01-21T04:31:50Z")

</div>

Hello, I am trying to improve some code I have, specifically to reduce the allocations it makes in a hot inner loop. I’ve been using Profile and julia --track-allocation=user to inspect on what lines the bulk of the all…

---

## [Makie mouse event](https://discourse.julialang.org/t/makie-mouse-event/74786)

<div class="topic-metadata">

**Author:** [@sransome](https://discourse.julialang.org/u/sransome)\
**Replies:** 10\
**Last updated:** [January 21, 2022, 1:49am UTC](https://discourse.julialang.org/t/makie-mouse-event/74786 "2022-01-21T01:49:27Z")

</div>

Hi, I’m using the following to respond to mouse clicks for a chart with multiple Axis, ax1, ax2,ax3. on(events(ax1.scene).mousebutton, priority = 0) do event if event.button == Mouse.left printl…

---

## [Franklin: render csv file in new browser tab](https://discourse.julialang.org/t/franklin-render-csv-file-in-new-browser-tab/74922)

<div class="topic-metadata">

**Author:** [@paradoxical-rhapsody](https://discourse.julialang.org/u/paradoxical-rhapsody)\
**Replies:** 3\
**Last updated:** [January 21, 2022, 1:15am UTC](https://discourse.julialang.org/t/franklin-render-csv-file-in-new-browser-tab/74922 "2022-01-21T01:15:56Z")

</div>

Using Franklin, I have created a static site. Now I would like to add a link to a CSV file, writen as \[data file\](example.csv) in markdown, in page home/dataexpo. The normal usage of \[data file\](example.csv) leads to do…

[Previous page](https://discourse.julialang.org/latest.md?page=1144)

[Next page](https://discourse.julialang.org/latest.md?page=1146)