# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1513

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

**Page:** 1514

---

## [Revise and structure-local functions](https://discourse.julialang.org/t/revise-and-structure-local-functions/53914)

<div class="topic-metadata">

**Author:** [@fieker](https://discourse.julialang.org/u/fieker)\
**Replies:** 3\
**Last updated:** [January 25, 2021, 3:33pm UTC](https://discourse.julialang.org/t/revise-and-structure-local-functions/53914 "2021-01-25T15:33:11Z")

</div>

Consider the following (pointless) module: module ReviseCrash struct Blah a::Int function Blah() return new(), x-\>f1() end function f1() return 3 end end function f2() return 1 end end The cons…

---

## [How to collaborate with others over branches in separate packages?](https://discourse.julialang.org/t/how-to-collaborate-with-others-over-branches-in-separate-packages/53909)

<div class="topic-metadata">

**Author:** [@dlfivefifty](https://discourse.julialang.org/u/dlfivefifty)\
**Replies:** 0\
**Last updated:** [January 25, 2021, 1:51pm UTC](https://discourse.julialang.org/t/how-to-collaborate-with-others-over-branches-in-separate-packages/53909 "2021-01-25T13:51:08Z")

</div>

When adding new features that require changes amongst different packages I tend to work in separate branches in each package which are cloned and \] deved locally. But how do I share the branches with other collaborators? …

---

## [Type stability problem (Vcat, Tuple and function)](https://discourse.julialang.org/t/type-stability-problem-vcat-tuple-and-function/53862)

<div class="topic-metadata">

**Author:** [@Marcell\_Havlik](https://discourse.julialang.org/u/Marcell_Havlik)\
**Replies:** 8\
**Last updated:** [January 25, 2021, 1:24pm UTC](https://discourse.julialang.org/t/type-stability-problem-vcat-tuple-and-function/53862 "2021-01-25T13:24:43Z")

</div>

Hey Julianners, I am working on type stability and I just can’t understand what is going on here. Finally I could minimalise my example to 3 line. @code\_warntype (vcat(\[randn(1,1,3) for i in 1:3\]...)) baz() = (vcat(\[ra…

---

## [Problems with package Interact](https://discourse.julialang.org/t/problems-with-package-interact/53907)

<div class="topic-metadata">

**Author:** [@angeloaliano1](https://discourse.julialang.org/u/angeloaliano1)\
**Replies:** 0\
**Last updated:** [January 25, 2021, 1:13pm UTC](https://discourse.julialang.org/t/problems-with-package-interact/53907 "2021-01-25T13:13:20Z")

</div>

Dear all, I just to install Julia 1.5.3 from oficial site (Julia Pro). I have installed the packages Plots and Interact. Plots, alone, works perfectly. However, when I run: using Plots, Interact plotly() xh = range(…

---

## [List of elements with unknown type, is it bad?](https://discourse.julialang.org/t/list-of-elements-with-unknown-type-is-it-bad/53893)

<div class="topic-metadata">

**Author:** [@rveltz](https://discourse.julialang.org/u/rveltz)\
**Replies:** 3\
**Last updated:** [January 25, 2021, 1:14pm UTC](https://discourse.julialang.org/t/list-of-elements-with-unknown-type-is-it-bad/53893 "2021-01-25T13:14:42Z")

</div>

Hi, I have a project where I need to append to a result list, several objects depending on conditions. A MWE is presented in the following code. In practice, I have more subtypes of ABS (like ~10). I would like foo to b…

---

## [Julian way of defining custom numeric types](https://discourse.julialang.org/t/julian-way-of-defining-custom-numeric-types/53866)

<div class="topic-metadata">

**Author:** [@cshen](https://discourse.julialang.org/u/cshen)\
**Replies:** 6\
**Last updated:** [January 25, 2021, 7:10am UTC](https://discourse.julialang.org/t/julian-way-of-defining-custom-numeric-types/53866 "2021-01-25T07:10:42Z")

</div>

Hello, I am working with the DifferentialEquations package to play around some differential equations involving angles. Instead of letting everything go on as a normal float and just afterwards reduce everything modulo…

---

## [Comparisons between Julia (NeuralPDE.jl and DiffEqFlux.jl) and DeepXDE python package?](https://discourse.julialang.org/t/comparisons-between-julia-neuralpde-jl-and-diffeqflux-jl-and-deepxde-python-package/52669)

<div class="topic-metadata">

**Author:** [@bad\_at\_math](https://discourse.julialang.org/u/bad_at_math)\
**Replies:** 3\
**Last updated:** [January 25, 2021, 6:07am UTC](https://discourse.julialang.org/t/comparisons-between-julia-neuralpde-jl-and-diffeqflux-jl-and-deepxde-python-package/52669 "2021-01-25T06:07:18Z")

</div>

Hello everyone, I’ve recently come across the DeepXDE python package (https://github.com/lululxvi/deepxde), which can be used for formulating and solving a variety of neural differential equation - type problems. Beyond …

---

## [Error with ForwardDiff Dual numbers (DifferentialEquations, and Turing)](https://discourse.julialang.org/t/error-with-forwarddiff-dual-numbers-differentialequations-and-turing/53103)

<div class="topic-metadata">

**Author:** [@haganeno](https://discourse.julialang.org/u/haganeno)\
**Replies:** 5\
**Last updated:** [January 25, 2021, 6:03am UTC](https://discourse.julialang.org/t/error-with-forwarddiff-dual-numbers-differentialequations-and-turing/53103 "2021-01-25T06:03:21Z")

</div>

I am trying to estimate parameters for an ODE system using Turing, ForwardDiff, and DifferentialEquations. However, I consistently get the following error: julia\> TypeError: in setfield!, expected Float64, got ForwardDi…

---

## [Looking to create something like pythex](https://discourse.julialang.org/t/looking-to-create-something-like-pythex/52633)

<div class="topic-metadata">

**Author:** [@bicepjai](https://discourse.julialang.org/u/bicepjai)\
**Replies:** 4\
**Last updated:** [January 25, 2021, 5:27am UTC](https://discourse.julialang.org/t/looking-to-create-something-like-pythex/52633 "2021-01-25T05:27:30Z")

</div>

When I was doing advent of code 2020 in julia, I noticed there were no good resource like pythex.org to test out the julia regular expression results. Looking up resources to host a simple web app that can solve this. Ca…

---

## [CSV.read provide a valid sink error](https://discourse.julialang.org/t/csv-read-provide-a-valid-sink-error/53878)

<div class="topic-metadata">

**Author:** [@Jared\_shay](https://discourse.julialang.org/u/Jared_shay)\
**Replies:** 9\
**Last updated:** [January 25, 2021, 3:31am UTC](https://discourse.julialang.org/t/csv-read-provide-a-valid-sink-error/53878 "2021-01-25T03:31:01Z")

</div>

I tried to read local csv files in julialang. To do so, I did the following from julia terminal (windows): using CSV df = CSV.read("C:\\\\Users\\\\adam\\\\data-example\\\\glass.csv") but I got following error: ERROR: Argumen…

---

## [How to avoid ForwardDiff.jl generating a second-order derivative that wastes flops by eventually multiplying by zero](https://discourse.julialang.org/t/how-to-avoid-forwarddiff-jl-generating-a-second-order-derivative-that-wastes-flops-by-eventually-multiplying-by-zero/53845)

<div class="topic-metadata">

**Author:** [@schneiderfelipe](https://discourse.julialang.org/u/schneiderfelipe)\
**Replies:** 10\
**Last updated:** [January 25, 2021, 2:28am UTC](https://discourse.julialang.org/t/how-to-avoid-forwarddiff-jl-generating-a-second-order-derivative-that-wastes-flops-by-eventually-multiplying-by-zero/53845 "2021-01-25T02:28:23Z")

</div>

I played around with second derivatives and ForwardDiff.jl and found something unexpected, so I would like to ask about it. Basically, the generated LLVM representation is multiplying a whole code branch by zero before r…

---

## [Interact isn't generating anything in Juno for me anymore](https://discourse.julialang.org/t/interact-isnt-generating-anything-in-juno-for-me-anymore/42341)

<div class="topic-metadata">

**Author:** [@jrdegreeff](https://discourse.julialang.org/u/jrdegreeff)\
**Replies:** 3\
**Last updated:** [January 25, 2021, 2:00am UTC](https://discourse.julialang.org/t/interact-isnt-generating-anything-in-juno-for-me-anymore/42341 "2021-01-25T02:00:54Z")

</div>

I have been using the Interact.jl package within Juno for a little while now. Until recently it worked exactly as expected and created interactive elements in the plots window. However, while playing around recently wit…

---

## [Workflow to develop standalone scripts that depend on both standard and custom Packages](https://discourse.julialang.org/t/workflow-to-develop-standalone-scripts-that-depend-on-both-standard-and-custom-packages/53873)

<div class="topic-metadata">

**Author:** [@anglyan](https://discourse.julialang.org/u/anglyan)\
**Replies:** 8\
**Last updated:** [January 25, 2021, 1:50am UTC](https://discourse.julialang.org/t/workflow-to-develop-standalone-scripts-that-depend-on-both-standard-and-custom-packages/53873 "2021-01-25T01:50:51Z")

</div>

Hi, I have been using Julia on and off for the past four years, and one of the things that I am still struggling with is the lack of a consistent workflow to develop and run standalone scripts that depend on a common se…

---

## [Can't Run Interact](https://discourse.julialang.org/t/cant-run-interact/53884)

<div class="topic-metadata">

**Author:** [@bobmccrory](https://discourse.julialang.org/u/bobmccrory)\
**Replies:** 0\
**Last updated:** [January 25, 2021, 1:25am UTC](https://discourse.julialang.org/t/cant-run-interact/53884 "2021-01-25T01:25:24Z")

</div>

I’m running a pretty standard Windows 10 laptop with the latest Anaconda and JuliaPro installed. When I try to install and run Interact with one of the sample Interact workbooks (the Introduction), it complains that it c…

---

## [How to enforce minimum dimensions for arrays that might be scalars?](https://discourse.julialang.org/t/how-to-enforce-minimum-dimensions-for-arrays-that-might-be-scalars/53860)

<div class="topic-metadata">

**Author:** [@marty0801](https://discourse.julialang.org/u/marty0801)\
**Replies:** 3\
**Last updated:** [January 24, 2021, 7:27pm UTC](https://discourse.julialang.org/t/how-to-enforce-minimum-dimensions-for-arrays-that-might-be-scalars/53860 "2021-01-24T19:27:58Z")

</div>

I have a function expecting a Matrix and a Vector argument: function f(m::Matrix, v::Vector) ... end Inside f performs some linear algebra. My problem: I need f to work when its arguments are scalars as well. How shou…

---

## [Very slow loop](https://discourse.julialang.org/t/very-slow-loop/53608)

<div class="topic-metadata">

**Author:** [@jmcastro2109](https://discourse.julialang.org/u/jmcastro2109)\
**Replies:** 33\
**Last updated:** [January 24, 2021, 7:26pm UTC](https://discourse.julialang.org/t/very-slow-loop/53608 "2021-01-24T19:26:26Z")

</div>

Hi all, I am trying to speed up this loop. I am providing a MWE and I wanted to know if any of you could spot any obvious performance improvementes. using LinearAlgebra, Statistics, Random C=rand(\[0,1\],120,13,8000) D…

---

## [Vs code debugger launch](https://discourse.julialang.org/t/vs-code-debugger-launch/53580)

<div class="topic-metadata">

**Author:** [@mkarikom](https://discourse.julialang.org/u/mkarikom)\
**Replies:** 1\
**Last updated:** [January 24, 2021, 5:51pm UTC](https://discourse.julialang.org/t/vs-code-debugger-launch/53580 "2021-01-24T17:51:12Z")

</div>

Is there any way to launch the debugger on single line or REPL command or does it have to be run on the whole file? Something like Juno.@enter?

---

## [Fellowships for Research Software Engineers in the UK](https://discourse.julialang.org/t/fellowships-for-research-software-engineers-in-the-uk/41685)

<div class="topic-metadata">

**Author:** [@dawbarton](https://discourse.julialang.org/u/dawbarton)\
**Replies:** 7\
**Last updated:** [January 24, 2021, 3:08pm UTC](https://discourse.julialang.org/t/fellowships-for-research-software-engineers-in-the-uk/41685 "2021-01-24T15:08:56Z")

</div>

I don’t know if anyone is interested in becoming a Research Software Engineer in the UK but if so, there is a call for fellowships coming out shortly https://epsrc.ukri.org/funding/calls/pre-announcement-for-research-sof…

---

## [How to bring a system of differential equations to zero with DifferentialEquations?](https://discourse.julialang.org/t/how-to-bring-a-system-of-differential-equations-to-zero-with-differentialequations/53659)

<div class="topic-metadata">

**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 15\
**Last updated:** [January 24, 2021, 12:59pm UTC](https://discourse.julialang.org/t/how-to-bring-a-system-of-differential-equations-to-zero-with-differentialequations/53659 "2021-01-24T12:59:30Z")

</div>

I have a population model described by this system of differential equations: dN/dt = μN(1-(N+I)/κ) -φNP -ωN dI/dt = φNP -ηI -ωI dP/dt = βηI -φNP -ωP with κ = 2.2 ⋅ 10^7 μ = 0.47 φ = 10^-9 β = 50 η = 1.0 ω = 0.05 Thi…

---

## [How to connect an event handler to a button in Makie.jl?](https://discourse.julialang.org/t/how-to-connect-an-event-handler-to-a-button-in-makie-jl/53851)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 3\
**Last updated:** [January 24, 2021, 9:13am UTC](https://discourse.julialang.org/t/how-to-connect-an-event-handler-to-a-button-in-makie-jl/53851 "2021-01-24T09:13:47Z")

</div>

How can I execute a function when I press a button in Makie? This is missing in the documentation. Example: using GeometryBasics, GLMakie function reset() # set camera and zoom to default values end function mai…

---

## [Generate random positive definite symmetric matrix](https://discourse.julialang.org/t/generate-random-positive-definite-symmetric-matrix/53816)

<div class="topic-metadata">

**Author:** [@biona001](https://discourse.julialang.org/u/biona001)\
**Replies:** 10\
**Last updated:** [January 24, 2021, 10:19am UTC](https://discourse.julialang.org/t/generate-random-positive-definite-symmetric-matrix/53816 "2021-01-24T10:19:38Z")

</div>

Can Julia or some existing package simulate random covariance (symmetric + positive definite) matrices? I could do using LinearAlgebra function random\_covariance\_matrix(n::Int) x = rand(n, n) xsym = 0.5(x + x')…

---

## [Infeasible LP and Farkas Certificate](https://discourse.julialang.org/t/infeasible-lp-and-farkas-certificate/53852)

<div class="topic-metadata">

**Author:** [@Mahbubar06](https://discourse.julialang.org/u/Mahbubar06)\
**Replies:** 2\
**Last updated:** [January 24, 2021, 9:23am UTC](https://discourse.julialang.org/t/infeasible-lp-and-farkas-certificate/53852 "2021-01-24T09:23:29Z")

</div>

Is there any JuMP (or other) method to retrieve Farkas certificate from an infeasible lp model? I am using Clp, Gurobi, or Ipopt solver for solving the lp problem modeled using JuMP. Thank you.

---

## [Writing CSV or TXT files to be read by VBA script (not just opened by excel)](https://discourse.julialang.org/t/writing-csv-or-txt-files-to-be-read-by-vba-script-not-just-opened-by-excel/53857)

<div class="topic-metadata">

**Author:** [@Peter-Jolly](https://discourse.julialang.org/u/Peter-Jolly)\
**Replies:** 2\
**Last updated:** [January 24, 2021, 9:10am UTC](https://discourse.julialang.org/t/writing-csv-or-txt-files-to-be-read-by-vba-script-not-just-opened-by-excel/53857 "2021-01-24T09:10:23Z")

</div>

I have been trying to prepare either \*.txt or \*.csv files from Julia to be read by a VBA script. It appears that the files prepared by Julia NOT PUT a carriage return(CR) line feed(LF) at the end of each line. It seems V…

---

## [How to set a systems of ODEs to zero with Boundary Value Problem?](https://discourse.julialang.org/t/how-to-set-a-systems-of-odes-to-zero-with-boundary-value-problem/53771)

<div class="topic-metadata">

**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 1\
**Last updated:** [January 24, 2021, 6:58am UTC](https://discourse.julialang.org/t/how-to-set-a-systems-of-odes-to-zero-with-boundary-value-problem/53771 "2021-01-24T06:58:06Z")

</div>

I have a system of ordinary differential equations (ODEs) that model the interaction between a bacterium and phage: dN/dt = μN(1-(N+I)/κ) -φNP -ωN dI/dt = φNP -ηI -ωI dP/dt = βηI -φNP -ωP I am looking for the values of…

---

## [How to understand the keyword \`where\` in the array type signature](https://discourse.julialang.org/t/how-to-understand-the-keyword-where-in-the-array-type-signature/53856)

<div class="topic-metadata">

**Author:** [@chkwon](https://discourse.julialang.org/u/chkwon)\
**Replies:** 2\
**Last updated:** [January 24, 2021, 5:08am UTC](https://discourse.julialang.org/t/how-to-understand-the-keyword-where-in-the-array-type-signature/53856 "2021-01-24T05:08:01Z")

</div>

a = Array{Int}\[\] push!(a, \[1 2; 3 4\]) @show typeof(a) Array{Array{Int64,N} where N,1} In the above, how should I read where N,1? Especially, what does 1 represent here? How may I create a variable of type Array{Array{…

---

## [Using Opensource hosting repo instead of GitHub](https://discourse.julialang.org/t/using-opensource-hosting-repo-instead-of-github/53592)

<div class="topic-metadata">

**Author:** [@vedasulo](https://discourse.julialang.org/u/vedasulo)\
**Replies:** 15\
**Last updated:** [January 24, 2021, 1:28am UTC](https://discourse.julialang.org/t/using-opensource-hosting-repo-instead-of-github/53592 "2021-01-24T01:28:26Z")

</div>

i see nobody using gitlab, Could i fork and make copy of all your work on Gitlab (opensource code hosting framework). I would like to see https://github.com/JuliaLang/julia project would available in Gitlab too. edi…

---

## [How should I simplify nested loops?](https://discourse.julialang.org/t/how-should-i-simplify-nested-loops/53835)

<div class="topic-metadata">

**Author:** [@Jared\_shay](https://discourse.julialang.org/u/Jared_shay)\
**Replies:** 34\
**Last updated:** [January 23, 2021, 11:19pm UTC](https://discourse.julialang.org/t/how-should-i-simplify-nested-loops/53835 "2021-01-23T23:19:35Z")

</div>

I am trying to understand the julia codes I am learning, and I find it difficult to understand the nested loop, don’t know how that should be simplified instead. Since I am comfortable with python, I tried to understand …

---

## [How can I load a polygonal 2D mesh (VTK format) into JuAFEM?](https://discourse.julialang.org/t/how-can-i-load-a-polygonal-2d-mesh-vtk-format-into-juafem/53831)

<div class="topic-metadata">

**Author:** [@gedankenexperiment](https://discourse.julialang.org/u/gedankenexperiment)\
**Replies:** 1\
**Last updated:** [January 23, 2021, 10:39pm UTC](https://discourse.julialang.org/t/how-can-i-load-a-polygonal-2d-mesh-vtk-format-into-juafem/53831 "2021-01-23T22:39:11Z")

</div>

Hi, I want to solve a reaction-diffusion equation on a 2D polygonal mesh, where each cell has a different parameter value for the reaction-diffusion equation. I have the mesh in the VTK format. Now I wonder whether I sho…

---

## [\[ANN\] ScanByte.jl](https://discourse.julialang.org/t/ann-scanbyte-jl/53847)

<div class="topic-metadata">

**Author:** [@jakobnissen](https://discourse.julialang.org/u/jakobnissen)\
**Replies:** 0\
**Last updated:** [January 23, 2021, 10:30pm UTC](https://discourse.julialang.org/t/ann-scanbyte-jl/53847 "2021-01-23T22:30:25Z")

</div>

I’m pleased to announce my package ScanByte.jl. The package does one simple thing: Given an array of bytes to search, and a set of bytes to search for, finds the first occurence of any byte in the set. The package is us…

---

## [Optimizing a quadratic binary function on CPLEX/JuMP](https://discourse.julialang.org/t/optimizing-a-quadratic-binary-function-on-cplex-jump/53800)

<div class="topic-metadata">

**Author:** [@angeloaliano1](https://discourse.julialang.org/u/angeloaliano1)\
**Replies:** 11\
**Last updated:** [January 23, 2021, 10:22pm UTC](https://discourse.julialang.org/t/optimizing-a-quadratic-binary-function-on-cplex-jump/53800 "2021-01-23T22:22:07Z")

</div>

I am using CPLEX 12.8 in JuMP to minimize a quadratic binary nonconvex function, according to quadratic function by CPLEX. In particular, my function is the following: \\sum\_{i=1}^{m-1} \\sum\_{f=1}^{F} \\sum\_{\\underset{\\…

[Previous page](https://discourse.julialang.org/latest.md?page=1512)

[Next page](https://discourse.julialang.org/latest.md?page=1514)