# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1172

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

**Page:** 1173

---

## [Passing pointers to workers process results in null pointers](https://discourse.julialang.org/t/passing-pointers-to-workers-process-results-in-null-pointers/73418)

<div class="topic-metadata">

**Author:** [@Bossax](https://discourse.julialang.org/u/Bossax)\
**Replies:** 4\
**Last updated:** [December 21, 2021, 8:26am UTC](https://discourse.julialang.org/t/passing-pointers-to-workers-process-results-in-null-pointers/73418 "2021-12-21T08:26:05Z")

</div>

Hi all, I am writing a code to spawn an image acquisition routine on a worker process by passing a pointer pointing to a camera device. This pointer is used by C APIs to execute camera operations via ccall. The problem …

---

## [JuliaMono displays different on Windows Notepad](https://discourse.julialang.org/t/juliamono-displays-different-on-windows-notepad/73366)

<div class="topic-metadata">

**Author:** [@nandoconde](https://discourse.julialang.org/u/nandoconde)\
**Replies:** 3\
**Last updated:** [December 21, 2021, 8:21am UTC](https://discourse.julialang.org/t/juliamono-displays-different-on-windows-notepad/73366 "2021-12-21T08:21:40Z")

</div>

Hello! I noticed a difference in how Γ\_T is displayed on Julia Terminal (with JuliaMono font) vs. Windows Notepad (with JuliaMono font). Julia Terminal Windows Notepad Do notice how the Γ is shorter in Notepad, a…

---

## [Couldn't reach Julia Chinese community for couple of days](https://discourse.julialang.org/t/couldnt-reach-julia-chinese-community-for-couple-of-days/73411)

<div class="topic-metadata">

**Author:** [@frydaydeep](https://discourse.julialang.org/u/frydaydeep)\
**Replies:** 1\
**Last updated:** [December 21, 2021, 3:49am UTC](https://discourse.julialang.org/t/couldnt-reach-julia-chinese-community-for-couple-of-days/73411 "2021-12-21T03:49:30Z")

</div>

there is this little ring just won’t stop rolling when I try to open something. Besides, I don’t know why it’s unsafe now:

---

## [How to restore the default view of Plot window in VS? 2](https://discourse.julialang.org/t/how-to-restore-the-default-view-of-plot-window-in-vs-2/72807)

<div class="topic-metadata">

**Author:** [@rmsmsgood](https://discourse.julialang.org/u/rmsmsgood)\
**Replies:** 2\
**Last updated:** [December 21, 2021, 8:09am UTC](https://discourse.julialang.org/t/how-to-restore-the-default-view-of-plot-window-in-vs-2/72807 "2021-12-21T08:09:10Z")

</div>

This topic has exactly same title this topic: https://discourse.julialang.org/t/how-to-restore-the-default-view-of-plot-window-in-vs/72776?u=rmsmsgood Before VS code version 1.63, the plot() opens new splited section…

---

## [Constant propagation depth](https://discourse.julialang.org/t/constant-propagation-depth/73012)

<div class="topic-metadata">

**Author:** [@Marco\_Lombardi](https://discourse.julialang.org/u/Marco_Lombardi)\
**Replies:** 6\
**Last updated:** [December 21, 2021, 3:15am UTC](https://discourse.julialang.org/t/constant-propagation-depth/73012 "2021-12-21T03:15:35Z")

</div>

Is there a limit in the depth of a tree for constant propagation? I have seen that rather long expressions involving only constants are not completely replaced by their result: julia\> c() = log(log(log(log(2\*π) + 2) + π…

---

## [Task serialization error: Running a Task on a remote process fails with "cannot serialize a running Task"](https://discourse.julialang.org/t/task-serialization-error-running-a-task-on-a-remote-process-fails-with-cannot-serialize-a-running-task/72812)

<div class="topic-metadata">

**Author:** [@Bossax](https://discourse.julialang.org/u/Bossax)\
**Replies:** 2\
**Last updated:** [December 21, 2021, 4:59am UTC](https://discourse.julialang.org/t/task-serialization-error-running-a-task-on-a-remote-process-fails-with-cannot-serialize-a-running-task/72812 "2021-12-21T04:59:16Z")

</div>

Hi all, I have written a routine to do image acquisition. This routine calls camera C APIs to take and save images. I tested it by running the routine on a local process and it works fine; I can send SIGINT to interrupt…

---

## [Running External Programs in windows](https://discourse.julialang.org/t/running-external-programs-in-windows/72353)

<div class="topic-metadata">

**Author:** [@Daniel\_Lewis](https://discourse.julialang.org/u/Daniel_Lewis)\
**Replies:** 5\
**Last updated:** [December 21, 2021, 2:42am UTC](https://discourse.julialang.org/t/running-external-programs-in-windows/72353 "2021-12-21T02:42:56Z")

</div>

hello, I’m trying to capture an image from a webcam using Windows 10. I have FFmpeg install and I can capture an image using the cmd command: ffmpeg -f dshow -video\_size 1920x1080 -i "video=HD Pro Webcam C920" -frames…

---

## [Problem with mutation and copying of Matrices/Vectors](https://discourse.julialang.org/t/problem-with-mutation-and-copying-of-matrices-vectors/73221)

<div class="topic-metadata">

**Author:** [@Amro](https://discourse.julialang.org/u/Amro)\
**Replies:** 22\
**Last updated:** [December 21, 2021, 12:23am UTC](https://discourse.julialang.org/t/problem-with-mutation-and-copying-of-matrices-vectors/73221 "2021-12-21T00:23:34Z")

</div>

I have the below MWE of my code. Here, R.I\_prev = R.I; is working as copy but I found that it works as mutation in my code, so any change of R.I will change directly R.I\_prev. I faced this issue many times. Can any body…

---

## [Can't run python script](https://discourse.julialang.org/t/cant-run-python-script/73398)

<div class="topic-metadata">

**Author:** [@anon69491625](https://discourse.julialang.org/u/anon69491625)\
**Replies:** 14\
**Last updated:** [December 20, 2021, 11:36pm UTC](https://discourse.julialang.org/t/cant-run-python-script/73398 "2021-12-20T23:36:18Z")

</div>

Hi All trying out julia and Pluto for the first time. I “thought” was doing everything correctly but obviously not. I get "The Python package test\_ib\_60\_sec.py could not be imported by pyimport." and ModuleNotFoundEr…

---

## [Optional field in struct](https://discourse.julialang.org/t/optional-field-in-struct/73338)

<div class="topic-metadata">

**Author:** [@Handam](https://discourse.julialang.org/u/Handam)\
**Replies:** 3\
**Last updated:** [December 20, 2021, 11:33pm UTC](https://discourse.julialang.org/t/optional-field-in-struct/73338 "2021-12-20T23:33:14Z")

</div>

Hi, if I have defined a struct, e.g. mutable struct A a::Tuple end and then saved an object of this struct with BSON o = A((1,2)) BSON.@save "o.bson" o is it then possible to add “optional” fields to the struct …

---

## [DFbetas for identifying influential participants - linear mixed models](https://discourse.julialang.org/t/dfbetas-for-identifying-influential-participants-linear-mixed-models/73399)

<div class="topic-metadata">

**Author:** [@CatOliveira](https://discourse.julialang.org/u/CatOliveira)\
**Replies:** 1\
**Last updated:** [December 20, 2021, 11:23pm UTC](https://discourse.julialang.org/t/dfbetas-for-identifying-influential-participants-linear-mixed-models/73399 "2021-12-20T23:23:10Z")

</div>

Hello everyone, I have used the package influence.me to determine whether I had influential participants using dfbetas. Yet, this package takes forever to run and I just can’t wait another month for it to run. I tried t…

---

## [Why does VSCode say there is a problem in this code?](https://discourse.julialang.org/t/why-does-vscode-say-there-is-a-problem-in-this-code/73280)

<div class="topic-metadata">

**Author:** [@Soldalma](https://discourse.julialang.org/u/Soldalma)\
**Replies:** 11\
**Last updated:** [December 20, 2021, 11:18pm UTC](https://discourse.julialang.org/t/why-does-vscode-say-there-is-a-problem-in-this-code/73280 "2021-12-20T23:18:30Z")

</div>

I created a file with the exact contents below. It runs fine, but VSCode keeps listing the file and the line with the select statement in the Problems tab. Three questions: What is the problem? My guess is that it i…

---

## [Run Julia/Makie simulations in Blender](https://discourse.julialang.org/t/run-julia-makie-simulations-in-blender/72796)

<div class="topic-metadata">

**Author:** [@Chimel](https://discourse.julialang.org/u/Chimel)\
**Replies:** 7\
**Last updated:** [December 20, 2021, 10:57pm UTC](https://discourse.julialang.org/t/run-julia-makie-simulations-in-blender/72796 "2021-12-20T22:57:41Z")

</div>

Hello, Blender user here, new to Julia. I ran into a Tweet with a cool Protein simuation done with the BioMakie.jl Julia program, and wanted to know if it is possible to export the simulation data to use it in Blender;…

---

## [Error: Assigning a set to multiple positions of a vector of sets](https://discourse.julialang.org/t/error-assigning-a-set-to-multiple-positions-of-a-vector-of-sets/73394)

<div class="topic-metadata">

**Author:** [@bast](https://discourse.julialang.org/u/bast)\
**Replies:** 3\
**Last updated:** [December 20, 2021, 10:25pm UTC](https://discourse.julialang.org/t/error-assigning-a-set-to-multiple-positions-of-a-vector-of-sets/73394 "2021-12-20T22:25:47Z")

</div>

Hi, I recently started working with Julia and I ran into an error that I do not understand. I have a vector of sets of which one set contains one element. I now have candidate elements that I would like to add to the e…

---

## [Advantages of explicitly using "map" or "broadcast" wrappers?](https://discourse.julialang.org/t/advantages-of-explicitly-using-map-or-broadcast-wrappers/73371)

<div class="topic-metadata">

**Author:** [@leon](https://discourse.julialang.org/u/leon)\
**Replies:** 5\
**Last updated:** [December 20, 2021, 9:57pm UTC](https://discourse.julialang.org/t/advantages-of-explicitly-using-map-or-broadcast-wrappers/73371 "2021-12-20T21:57:29Z")

</div>

For example, if I have four vectors A, B, C, and D, and my goal is to find the index of the rows with A\>-10, B\>15, C\>500 and D\>200. In Matlab I can achieve that by doing the below: Index1 = A\>-10 && B\>15 && C\>500 && D\>2…

---

## [Defining a custom hash function](https://discourse.julialang.org/t/defining-a-custom-hash-function/73395)

<div class="topic-metadata">

**Author:** [@jules](https://discourse.julialang.org/u/jules)\
**Replies:** 7\
**Last updated:** [December 20, 2021, 9:40pm UTC](https://discourse.julialang.org/t/defining-a-custom-hash-function/73395 "2021-12-20T21:40:59Z")

</div>

I have a type BezierPath that contains a vector of commands. I want two bezier paths with the same commands stored in different vectors to have the same hash value, by default they don’t. Is it fine to just overload hash …

---

## [An internal Julia plotting package?](https://discourse.julialang.org/t/an-internal-julia-plotting-package/73079)

<div class="topic-metadata">

**Author:** [@leon](https://discourse.julialang.org/u/leon)\
**Replies:** 62\
**Last updated:** [December 20, 2021, 8:40pm UTC](https://discourse.julialang.org/t/an-internal-julia-plotting-package/73079 "2021-12-20T20:40:24Z")

</div>

My understanding is that right now there are many Julia plotting packages but none of them is quite capable of producing high quality publication ready plots yet, is that right? I wonder if Julia could consider implement…

---

## [What makes Julia loops so fast?](https://discourse.julialang.org/t/what-makes-julia-loops-so-fast/73389)

<div class="topic-metadata">

**Author:** [@leon](https://discourse.julialang.org/u/leon)\
**Replies:** 8\
**Last updated:** [December 20, 2021, 7:48pm UTC](https://discourse.julialang.org/t/what-makes-julia-loops-so-fast/73389 "2021-12-20T19:48:54Z")

</div>

I did some test myself as below, it turns out the loop version of my code is close to 15 times faster. Why? What made Julia so fast when going through a loop? My code: A = rand(1:100, 10^5,1); @time Ind1 = A .\> 35; …

---

## [Lazy constraints with callback in gurobi](https://discourse.julialang.org/t/lazy-constraints-with-callback-in-gurobi/73367)

<div class="topic-metadata">

**Author:** [@ahmad88](https://discourse.julialang.org/u/ahmad88)\
**Replies:** 1\
**Last updated:** [December 20, 2021, 7:17pm UTC](https://discourse.julialang.org/t/lazy-constraints-with-callback-in-gurobi/73367 "2021-12-20T19:17:59Z")

</div>

Hi I have a model and when of model’s constraints is corresponding to cycles in the graph, so I am trying to add these cycle constraints as lazy constraints within the callback, so in each iteration, I am solving the mo…

---

## [Create plot with multiple colorgradients](https://discourse.julialang.org/t/create-plot-with-multiple-colorgradients/73383)

<div class="topic-metadata">

**Author:** [@DrChainsaw](https://discourse.julialang.org/u/DrChainsaw)\
**Replies:** 8\
**Last updated:** [December 20, 2021, 7:11pm UTC](https://discourse.julialang.org/t/create-plot-with-multiple-colorgradients/73383 "2021-12-20T19:11:02Z")

</div>

I’m trying to visualize some data where I want to see some kind of distribution a (small) set of per sample distributions. I doubt that the description makes much sense, but this MWE creates the type of figure I would l…

---

## [Find out number of function arguments or if passed at all](https://discourse.julialang.org/t/find-out-number-of-function-arguments-or-if-passed-at-all/73376)

<div class="topic-metadata">

**Author:** [@itchy00](https://discourse.julialang.org/u/itchy00)\
**Replies:** 8\
**Last updated:** [December 20, 2021, 6:35pm UTC](https://discourse.julialang.org/t/find-out-number-of-function-arguments-or-if-passed-at-all/73376 "2021-12-20T18:35:32Z")

</div>

Hi (This could be relevant for all kinds of functions in general, but I’ll give a specific example here). so I’m quite new to julia and currently trying to write a custom package/module with some data loading and proce…

---

## [\[ANN\] CircleFit.jl](https://discourse.julialang.org/t/ann-circlefit-jl/45773)

<div class="topic-metadata">

**Author:** [@feanor12](https://discourse.julialang.org/u/feanor12)\
**Replies:** 2\
**Last updated:** [December 20, 2021, 6:10pm UTC](https://discourse.julialang.org/t/ann-circlefit-jl/45773 "2021-12-20T18:10:39Z")

</div>

This is a simple package to fit a circle to points in a plane. Currently, there are 3 methods implemented (Kasa, Pratt, Taubin).

---

## ["ask\_dialog()" is not working proberly](https://discourse.julialang.org/t/ask-dialog-is-not-working-proberly/72685)

<div class="topic-metadata">

**Author:** [@Amro](https://discourse.julialang.org/u/Amro)\
**Replies:** 1\
**Last updated:** [December 6, 2021, 11:30pm UTC](https://discourse.julialang.org/t/ask-dialog-is-not-working-proberly/72685 "2021-12-06T23:30:08Z")

</div>

I am using ask\_dialog() in my code (Myfile.jl) and when I run it, a popup window is appeared. However, after clicking any of the two options nothing is happening (it do nothing). While using the below command in REPL it …

---

## [Inference problem with @spawn](https://discourse.julialang.org/t/inference-problem-with-spawn/73379)

<div class="topic-metadata">

**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 5\
**Last updated:** [December 20, 2021, 5:39pm UTC](https://discourse.julialang.org/t/inference-problem-with-spawn/73379 "2021-12-20T17:39:00Z")

</div>

This is a toy example of the problem. I want to sum a bunch of number is parallel, using a lock to reduce. Disconsidering the fact that the lock here is of course detrimental to performance (the actual use case is diffe…

---

## [Confusing ambiguous MethodError](https://discourse.julialang.org/t/confusing-ambiguous-methoderror/73380)

<div class="topic-metadata">

**Author:** [@NicholasWMRitchie](https://discourse.julialang.org/u/NicholasWMRitchie)\
**Replies:** 3\
**Last updated:** [December 20, 2021, 5:00pm UTC](https://discourse.julialang.org/t/confusing-ambiguous-methoderror/73380 "2021-12-20T17:00:10Z")

</div>

While using SQLite.jl, I’ve run into this error (but I don’t think it is really a SQLite question.) MethodError: promote\_type(::Type{Union{}}, ::Type{String}) is ambiguous. Candidates: promote\_type(::Type{Union{}}, ::…

---

## [Zygote/Flux not computing gradient with view/slice of tensor properly for MLP](https://discourse.julialang.org/t/zygote-flux-not-computing-gradient-with-view-slice-of-tensor-properly-for-mlp/67835)

<div class="topic-metadata">

**Author:** [@outlace](https://discourse.julialang.org/u/outlace)\
**Replies:** 19\
**Last updated:** [December 20, 2021, 4:57pm UTC](https://discourse.julialang.org/t/zygote-flux-not-computing-gradient-with-view-slice-of-tensor-properly-for-mlp/67835 "2021-12-20T16:57:02Z")

</div>

I am working on an implementation of an ML algorithm called SLIDE (sub-linear deep learning engine) from an academic paper. I’ve included a link to a gist of the code: https://gist.github.com/outlace/c81a15ab77c1c9cebb56…

---

## [Adding logarithmic or polynomial regression to series](https://discourse.julialang.org/t/adding-logarithmic-or-polynomial-regression-to-series/73170)

<div class="topic-metadata">

**Author:** [@YummyPampers2](https://discourse.julialang.org/u/YummyPampers2)\
**Replies:** 11\
**Last updated:** [December 20, 2021, 4:49pm UTC](https://discourse.julialang.org/t/adding-logarithmic-or-polynomial-regression-to-series/73170 "2021-12-20T16:49:42Z")

</div>

Good Day: I have been attempting to fit a logarithmic or polynomial trendline to the following series: I am currently using GLM.jl and plotting with StatsPlots.jl, but do not believe there are parameters I can adj…

---

## [Inverting Large Matrices (Overflow error)](https://discourse.julialang.org/t/inverting-large-matrices-overflow-error/73353)

<div class="topic-metadata">

**Author:** [@RandarserousRex](https://discourse.julialang.org/u/RandarserousRex)\
**Replies:** 4\
**Last updated:** [December 20, 2021, 4:29pm UTC](https://discourse.julialang.org/t/inverting-large-matrices-overflow-error/73353 "2021-12-20T16:29:56Z")

</div>

Hi all, I’m trying to invert a large matrix (1001 by 1001) to perform Ridge Regression in Julia. I’m running into this “Stack overflow Error:”, I’ve recreated the problem with simpler code (not my Ridge Regression code,…

---

## [Avoid double stacktrace when logging error](https://discourse.julialang.org/t/avoid-double-stacktrace-when-logging-error/73374)

<div class="topic-metadata">

**Author:** [@visr](https://discourse.julialang.org/u/visr)\
**Replies:** 1\
**Last updated:** [December 20, 2021, 4:28pm UTC](https://discourse.julialang.org/t/avoid-double-stacktrace-when-logging-error/73374 "2021-12-20T16:28:25Z")

</div>

I have a long running application with custom loggers set up, and when an error is thrown, I want to log that nicely with @error. This is done in a catch block, and works well. Since @error does not throw an error itself…

---

## [Dropout for the recurrent signal on LSTM units](https://discourse.julialang.org/t/dropout-for-the-recurrent-signal-on-lstm-units/73335)

<div class="topic-metadata">

**Author:** [@Maxim\_Lubov](https://discourse.julialang.org/u/Maxim_Lubov)\
**Replies:** 1\
**Last updated:** [December 20, 2021, 4:26pm UTC](https://discourse.julialang.org/t/dropout-for-the-recurrent-signal-on-lstm-units/73335 "2021-12-20T16:26:40Z")

</div>

Is there a possibility in Flux to apply dropout procedure to the recurrent input signal on the LSTM units, like recurrent\_dropout in Keras?

[Previous page](https://discourse.julialang.org/latest.md?page=1171)

[Next page](https://discourse.julialang.org/latest.md?page=1173)