# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1275

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

**Page:** 1276

---

## [Avoid negative Values](https://discourse.julialang.org/t/avoid-negative-values/67656)

<div class="topic-metadata">

**Author:** [@DerOzean](https://discourse.julialang.org/u/DerOzean)\
**Replies:** 13\
**Last updated:** [September 5, 2021, 3:47pm UTC](https://discourse.julialang.org/t/avoid-negative-values/67656 "2021-09-05T15:47:32Z")

</div>

Hi, I’m trying to solve a food-web with many interacting diffeq. Because animals and plants can’t have negative population sizes it would be great to restrict the solution to only positive values. Additionally some of t…

---

## [How to initialize a GeometryBasics.Point{2, Float32} that contains no point?](https://discourse.julialang.org/t/how-to-initialize-a-geometrybasics-point-2-float32-that-contains-no-point/67701)

<div class="topic-metadata">

**Author:** [@GoH](https://discourse.julialang.org/u/GoH)\
**Replies:** 7\
**Last updated:** [September 5, 2021, 11:45am UTC](https://discourse.julialang.org/t/how-to-initialize-a-geometrybasics-point-2-float32-that-contains-no-point/67701 "2021-09-05T11:45:43Z")

</div>

I am trying to initialize an empty GeometryBasics.Point{2, Float32}, could anyone help?

---

## [ANN: Nonconvex.jl a toolbox for AD-based constrained non-convex optimization](https://discourse.julialang.org/t/ann-nonconvex-jl-a-toolbox-for-ad-based-constrained-non-convex-optimization/59362)

<div class="topic-metadata">

**Author:** [@mohamed82008](https://discourse.julialang.org/u/mohamed82008)\
**Replies:** 34\
**Last updated:** [September 5, 2021, 11:30am UTC](https://discourse.julialang.org/t/ann-nonconvex-jl-a-toolbox-for-ad-based-constrained-non-convex-optimization/59362 "2021-09-05T11:30:22Z")

</div>

I am glad to announce Nonconvex.jl, a package in which I implement and wrap a few constrained nonlinear optimization algorithms and packages using automatic differentiation as a fundamental building block. There is no wa…

---

## [Makie animation: type FigureAxisPlot has no field plots](https://discourse.julialang.org/t/makie-animation-type-figureaxisplot-has-no-field-plots/67696)

<div class="topic-metadata">

**Author:** [@GoH](https://discourse.julialang.org/u/GoH)\
**Replies:** 2\
**Last updated:** [September 5, 2021, 8:35am UTC](https://discourse.julialang.org/t/makie-animation-type-figureaxisplot-has-no-field-plots/67696 "2021-09-05T08:35:38Z")

</div>

Hi i am trying to run the example code in http://juliaplots.org/MakieGallery.jl/stable/animation.html, but got an error of type FigureAxisPlot has no field plots getproperty(::Makie.FigureAxisPlot, ::Symbol)@Base.jl:33…

---

## [Gantt chart for profiling multi threaded code?](https://discourse.julialang.org/t/gantt-chart-for-profiling-multi-threaded-code/67672)

<div class="topic-metadata">

**Author:** [@jling](https://discourse.julialang.org/u/jling)\
**Replies:** 4\
**Last updated:** [September 5, 2021, 7:07am UTC](https://discourse.julialang.org/t/gantt-chart-for-profiling-multi-threaded-code/67672 "2021-09-05T07:07:42Z")

</div>

Investigating the bottleneck in a parallel program preventing it from scaling linearly like its C++ counterpart. The program includes I/O and uses CodeZlib (which has ccall). Trying to see how threads are spending time. …

---

## [Missing source file for local package](https://discourse.julialang.org/t/missing-source-file-for-local-package/67689)

<div class="topic-metadata">

**Author:** [@kobusherbst](https://discourse.julialang.org/u/kobusherbst)\
**Replies:** 10\
**Last updated:** [September 5, 2021, 6:37am UTC](https://discourse.julialang.org/t/missing-source-file-for-local-package/67689 "2021-09-05T06:37:30Z")

</div>

I have a module I am developing using Visual Studio Code on a Win 10 virtual machine. It is working fine. The source code is in a GitHub repository. I have cloned this repository to a different Win 10 virtual machine to …

---

## [Preserving HTML when processing Markdown](https://discourse.julialang.org/t/preserving-html-when-processing-markdown/12380)

<div class="topic-metadata">

**Author:** [@miles](https://discourse.julialang.org/u/miles)\
**Replies:** 0\
**Last updated:** [July 14, 2018, 7:47pm UTC](https://discourse.julialang.org/t/preserving-html-when-processing-markdown/12380 "2018-07-14T19:47:44Z")

</div>

Hi, I am using the built in Julia Markdown parser like this: html = Base.Markdown.html(Markdown.parse\_file(ifname)) Here “ifname” is a file containing Markdown text source. The result, “html” is a string that contains …

---

## [Using NLsolve to find multiple roots](https://discourse.julialang.org/t/using-nlsolve-to-find-multiple-roots/67637)

<div class="topic-metadata">

**Author:** [@roi.holtzman](https://discourse.julialang.org/u/roi.holtzman)\
**Replies:** 8\
**Last updated:** [September 5, 2021, 1:55am UTC](https://discourse.julialang.org/t/using-nlsolve-to-find-multiple-roots/67637 "2021-09-05T01:55:29Z")

</div>

I have two non-linear equations for which I want to find all roots. Using nlsolve only returns one root. How can I configure it to return all roots, say in some range of parameters?

---

## [Will Flux/Zygote compute gradients sparsely?](https://discourse.julialang.org/t/will-flux-zygote-compute-gradients-sparsely/67542)

<div class="topic-metadata">

**Author:** [@outlace](https://discourse.julialang.org/u/outlace)\
**Replies:** 7\
**Last updated:** [September 4, 2021, 10:30pm UTC](https://discourse.julialang.org/t/will-flux-zygote-compute-gradients-sparsely/67542 "2021-09-04T22:30:03Z")

</div>

So in short I want to train an MLP by sparsely updating it’s parameters. I do this on the forward pass by randomly subsampling the columns of my parameter matrices. E.g. for a simple 2 layer model on MINST with input dat…

---

## [Examples of analysis that can be done with SatelliteToolbox.jl](https://discourse.julialang.org/t/examples-of-analysis-that-can-be-done-with-satellitetoolbox-jl/19330)

<div class="topic-metadata">

**Author:** [@Ronis\_BR](https://discourse.julialang.org/u/Ronis_BR)\
**Replies:** 28\
**Last updated:** [September 4, 2021, 8:34pm UTC](https://discourse.julialang.org/t/examples-of-analysis-that-can-be-done-with-satellitetoolbox-jl/19330 "2021-09-04T20:34:58Z")

</div>

Hi guys! Just to let you know that I added to my blog a introductory post about the SatelliteToolbox.jl package: https://ronanarraes.com/tutorials/julia/the-satellitetoolbox-for-julia/ I also provided two examples of a…

---

## [\[ANN\] Smoothers: Collection of basic smoothers and smoother related applications](https://discourse.julialang.org/t/ann-smoothers-collection-of-basic-smoothers-and-smoother-related-applications/67687)

<div class="topic-metadata">

**Author:** [@viraltux](https://discourse.julialang.org/u/viraltux)\
**Replies:** 5\
**Last updated:** [September 4, 2021, 5:23pm UTC](https://discourse.julialang.org/t/ann-smoothers-collection-of-basic-smoothers-and-smoother-related-applications/67687 "2021-09-04T17:23:52Z")

</div>

In order to learn Julia I began building the package Forecast, after familiarizing myself with the language it was just natural to move from adding new models to the package to refactor it so that the package could bene…

---

## [@test\_throws make it difficult to debug unexpected exceptions](https://discourse.julialang.org/t/test-throws-make-it-difficult-to-debug-unexpected-exceptions/67698)

<div class="topic-metadata">

**Author:** [@Mark\_Nahabedian](https://discourse.julialang.org/u/Mark_Nahabedian)\
**Replies:** 0\
**Last updated:** [September 4, 2021, 4:16pm UTC](https://discourse.julialang.org/t/test-throws-make-it-difficult-to-debug-unexpected-exceptions/67698 "2021-09-04T16:16:42Z")

</div>

I’m using @test\_throws in a unit test to verify that the case being tested throws an expected exception. When that code throws a dipperent exception the test fails without giving a stack trace. It seems to me that if a…

---

## [Specify the admissible region of SIS model when plotting its phase portrait, using streamplot](https://discourse.julialang.org/t/specify-the-admissible-region-of-sis-model-when-plotting-its-phase-portrait-using-streamplot/67688)

<div class="topic-metadata">

**Author:** [@GoH](https://discourse.julialang.org/u/GoH)\
**Replies:** 4\
**Last updated:** [September 4, 2021, 2:43pm UTC](https://discourse.julialang.org/t/specify-the-admissible-region-of-sis-model-when-plotting-its-phase-portrait-using-streamplot/67688 "2021-09-04T14:43:05Z")

</div>

Hi I am trying to visualize the phase space of SIS model, but here is what I obtained. The problem is the trajectories should on the line of S+I=1, but somehow they did not, in the plot. here is my code begin using…

---

## [String formatting of plot labels produces "nothing"](https://discourse.julialang.org/t/string-formatting-of-plot-labels-produces-nothing/67693)

<div class="topic-metadata">

**Author:** [@dhryniuk](https://discourse.julialang.org/u/dhryniuk)\
**Replies:** 1\
**Last updated:** [September 4, 2021, 2:40pm UTC](https://discourse.julialang.org/t/string-formatting-of-plot-labels-produces-nothing/67693 "2021-09-04T14:40:45Z")

</div>

I would like to format strings to autonomously change the plotting labels depending on the parameters used. I tried using the Printf package and have been partially successful: label="⟨σ\_1 σ\_$s⟩$(@printf("%d", s))" pro…

---

## [ANN: MKLSparse](https://discourse.julialang.org/t/ann-mklsparse/3384)

<div class="topic-metadata">

**Author:** [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)\
**Replies:** 8\
**Last updated:** [September 4, 2021, 2:16pm UTC](https://discourse.julialang.org/t/ann-mklsparse/3384 "2021-09-04T14:16:21Z")

</div>

Hello everyone, I recently updated the MKLSparse.jl package for 0.5 and 0.6. The most useful feature of MKLSparse is likely the ability to seamlessly accelerate sparse matrix vector multiplications (which are the main …

---

## [Way to get string representation of an Expression?](https://discourse.julialang.org/t/way-to-get-string-representation-of-an-expression/7778)

<div class="topic-metadata">

**Author:** [@djsegal](https://discourse.julialang.org/u/djsegal)\
**Replies:** 6\
**Last updated:** [September 4, 2021, 2:04pm UTC](https://discourse.julialang.org/t/way-to-get-string-representation-of-an-expression/7778 "2021-09-04T14:04:55Z")

</div>

Let’s say you have a deeply nested Expr node. How do you turn that into a string that could (manually) be copied and pasted into the REPL? edit: related github issue#25121

---

## [What is the difference btween handling f\[i,j\]=GridLayout() and g=f\[i,j\]=GridLayout()](https://discourse.julialang.org/t/what-is-the-difference-btween-handling-f-i-j-gridlayout-and-g-f-i-j-gridlayout/67675)

<div class="topic-metadata">

**Author:** [@thudjx](https://discourse.julialang.org/u/thudjx)\
**Replies:** 7\
**Last updated:** [September 4, 2021, 1:37pm UTC](https://discourse.julialang.org/t/what-is-the-difference-btween-handling-f-i-j-gridlayout-and-g-f-i-j-gridlayout/67675 "2021-09-04T13:37:46Z")

</div>

I am trying to plot a 2x2 figure as shown below. So I import CairoMakie for ir in 1:2, ic in 1:2 g = f\[ir,ic\] = GridLayout() # handling g below end But if I try the following code: for ir in 1:2, ic in 1:…

---

## [Concurrency violation detect](https://discourse.julialang.org/t/concurrency-violation-detect/67678)

<div class="topic-metadata">

**Author:** [@Beh123](https://discourse.julialang.org/u/Beh123)\
**Replies:** 1\
**Last updated:** [September 4, 2021, 1:00pm UTC](https://discourse.julialang.org/t/concurrency-violation-detect/67678 "2021-09-04T13:00:32Z")

</div>

Hi everyone. I have 2 threads. First, is reading data from udp. Second, process data. When I use @distributed before loops, I have concurrency violation. This is my code. using Distributed , Sockets using ThreadPo…

---

## [RFC: Just In Time Compilation PoC promising 10x dynamic dispatch performance](https://discourse.julialang.org/t/rfc-just-in-time-compilation-poc-promising-10x-dynamic-dispatch-performance/47341)

<div class="topic-metadata">

**Author:** [@tisztamo](https://discourse.julialang.org/u/tisztamo)\
**Replies:** 0\
**Last updated:** [September 26, 2020, 10:33pm UTC](https://discourse.julialang.org/t/rfc-just-in-time-compilation-poc-promising-10x-dynamic-dispatch-performance/47341 "2020-09-26T22:33:08Z")

</div>

edit: There is the fresh new ManualDispatch.jl, a simple manual implementation of the same idea by @jlapeyre This started as a simple benchmark to better understand the performance characteristics of dynamic dispatch, b…

---

## [Can't find manifest files](https://discourse.julialang.org/t/cant-find-manifest-files/67683)

<div class="topic-metadata">

**Author:** [@wuxinyu](https://discourse.julialang.org/u/wuxinyu)\
**Replies:** 2\
**Last updated:** [September 4, 2021, 10:03am UTC](https://discourse.julialang.org/t/cant-find-manifest-files/67683 "2021-09-04T10:03:02Z")

</div>

Hello, I have some problems in environments. I have some manifest file in my computer. When I use gc from Pkg, it shows how many manifest file I have but I don’t know where are those files. How can I find those files?

---

## [Transparent plotting in Makie](https://discourse.julialang.org/t/transparent-plotting-in-makie/67625)

<div class="topic-metadata">

**Author:** [@yosuga](https://discourse.julialang.org/u/yosuga)\
**Replies:** 9\
**Last updated:** [September 4, 2021, 9:42am UTC](https://discourse.julialang.org/t/transparent-plotting-in-makie/67625 "2021-09-04T09:42:12Z")

</div>

BeautifulMakie is very helpful for 3D plotting. But, in this volume with scatters, x,y,z, f(x,y,z) example, I can’t see inside the box e.g. the values at (x,y,z)=(5,5,5) or (0,0,0). I want something like this example,“D…

---

## [Why is this FiniteDiff derivative wrong?](https://discourse.julialang.org/t/why-is-this-finitediff-derivative-wrong/67616)

<div class="topic-metadata">

**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 3\
**Last updated:** [September 4, 2021, 9:13am UTC](https://discourse.julialang.org/t/why-is-this-finitediff-derivative-wrong/67616 "2021-09-04T09:13:47Z")

</div>

What is going on here? using FiniteDiff randmat = rand(10, 2) sto = similar(randmat) function claytonsample!(sto, τ; randmat=randmat) sto .= randmat τ == 0 && return sto n = size(sto, 1) for i in 1:n …

---

## [Best way to define a set of differential equations?](https://discourse.julialang.org/t/best-way-to-define-a-set-of-differential-equations/67650)

<div class="topic-metadata">

**Author:** [@pafloxy](https://discourse.julialang.org/u/pafloxy)\
**Replies:** 6\
**Last updated:** [September 4, 2021, 9:11am UTC](https://discourse.julialang.org/t/best-way-to-define-a-set-of-differential-equations/67650 "2021-09-04T09:11:06Z")

</div>

Hi! I am using DifferentialEquations.jl for simulating trajectories over high-dimensional vector fields. For my case, the time-evolution function for each coordinate is generated by a pre-defined random function (\*\* sa…

---

## [How to avoid code duplication when defining a function with multiple methods?](https://discourse.julialang.org/t/how-to-avoid-code-duplication-when-defining-a-function-with-multiple-methods/67681)

<div class="topic-metadata">

**Author:** [@Giulio\_Benedetti](https://discourse.julialang.org/u/Giulio_Benedetti)\
**Replies:** 5\
**Last updated:** [September 4, 2021, 9:02am UTC](https://discourse.julialang.org/t/how-to-avoid-code-duplication-when-defining-a-function-with-multiple-methods/67681 "2021-09-04T09:02:44Z")

</div>

Hello! I am writing a long function which can take different numbers and types of arguments, so I am defining multiple methods to tackle each and every case. The function will behave similarly for every case, but there a…

---

## [Should Julia raise errors for illegal return type annotation?](https://discourse.julialang.org/t/should-julia-raise-errors-for-illegal-return-type-annotation/67359)

<div class="topic-metadata">

**Author:** [@greatpet](https://discourse.julialang.org/u/greatpet)\
**Replies:** 6\
**Last updated:** [September 4, 2021, 8:16am UTC](https://discourse.julialang.org/t/should-julia-raise-errors-for-illegal-return-type-annotation/67359 "2021-09-04T08:16:47Z")

</div>

It’s strange that Julia gives you errors for illegal type annotations for function arguments, but not return values (until runtime). julia\> f(x)::1 = x # illegal return type, no error f (generic function with 1 method) …

---

## [Installing julia v1.6.2 behind proxy](https://discourse.julialang.org/t/installing-julia-v1-6-2-behind-proxy/67624)

<div class="topic-metadata">

**Author:** [@vijaysrini08](https://discourse.julialang.org/u/vijaysrini08)\
**Replies:** 3\
**Last updated:** [September 4, 2021, 6:55am UTC](https://discourse.julialang.org/t/installing-julia-v1-6-2-behind-proxy/67624 "2021-09-04T06:55:03Z")

</div>

I am trying to install Julia on a linux box which is behind proxy. The installation of julia is quite easy, but the installation of modules is very exhausting. I tried setting up https\_proxy - Failed sslVerify: false…

---

## [Are generic types worth the complexity?](https://discourse.julialang.org/t/are-generic-types-worth-the-complexity/67658)

<div class="topic-metadata">

**Author:** [@Nathan\_Boyer](https://discourse.julialang.org/u/Nathan_Boyer)\
**Replies:** 9\
**Last updated:** [September 4, 2021, 5:40am UTC](https://discourse.julialang.org/t/are-generic-types-worth-the-complexity/67658 "2021-09-04T05:40:00Z")

</div>

When writing methods for a function in my package, I used abstract type declarations for two reasons: Type declarations will ensure a user gets MethodError rather than some other internal error if they use the wrong ty…

---

## [RAM+Swap exhausted while building sys image for Flux activity with PackageCompiler on RaspberryPi3 (Raspbian)](https://discourse.julialang.org/t/ram-swap-exhausted-while-building-sys-image-for-flux-activity-with-packagecompiler-on-raspberrypi3-raspbian/67636)

<div class="topic-metadata">

**Author:** [@Vyacheslav\_Vorobyov](https://discourse.julialang.org/u/Vyacheslav_Vorobyov)\
**Replies:** 4\
**Last updated:** [September 4, 2021, 1:16am UTC](https://discourse.julialang.org/t/ram-swap-exhausted-while-building-sys-image-for-flux-activity-with-packagecompiler-on-raspberrypi3-raspbian/67636 "2021-09-04T01:16:31Z")

</div>

To minimize start time of a Julia(1.6.2) program on RaspberryPI3, I tried to use PackageCompiler to build sys image for some activity done against Flux(only inference, not learn). After an hour of work of PackageCompiler…

---

## [Parametric type signature in methods, any actual difference?](https://discourse.julialang.org/t/parametric-type-signature-in-methods-any-actual-difference/67663)

<div class="topic-metadata">

**Author:** [@albheim](https://discourse.julialang.org/u/albheim)\
**Replies:** 3\
**Last updated:** [September 3, 2021, 9:59pm UTC](https://discourse.julialang.org/t/parametric-type-signature-in-methods-any-actual-difference/67663 "2021-09-03T21:59:45Z")

</div>

Was just curious if there was actually a difference in some way between these two ways of defining a method with parametric types. function f1(x::Vector{\<:Real}) # Stuff end function f2(x::Vector{T}) where T \<: Real…

---

## [Function to check if user input is between letters](https://discourse.julialang.org/t/function-to-check-if-user-input-is-between-letters/67668)

<div class="topic-metadata">

**Author:** [@hdcpereira](https://discourse.julialang.org/u/hdcpereira)\
**Replies:** 1\
**Last updated:** [September 3, 2021, 9:21pm UTC](https://discourse.julialang.org/t/function-to-check-if-user-input-is-between-letters/67668 "2021-09-03T21:21:53Z")

</div>

I’m trying to write a function that checks if the user wrote the proper input, if it is, return the input, if its not, asks the user to try again. It looks like this: function letter\_between\_AH() while false …

[Previous page](https://discourse.julialang.org/latest.md?page=1274)

[Next page](https://discourse.julialang.org/latest.md?page=1276)