# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1031

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

**Page:** 1032

---

## [Missing sparse methods](https://discourse.julialang.org/t/missing-sparse-methods/17596)

<div class="topic-metadata">

**Author:** [@Paul\_Hines](https://discourse.julialang.org/u/Paul_Hines)\
**Replies:** 3\
**Last updated:** [November 16, 2018, 6:24pm UTC](https://discourse.julialang.org/t/missing-sparse-methods/17596 "2018-11-16T18:24:10Z")

</div>

It seems like there are missing sparse matrix methods. In both 1.0.2 and 0.7 this code: using SparseArrays using LinearAlgebra A = sprand(10,10,.9) b\_dense = Array(sprand(10,1,.8)) # works b\_sparse = sprand(10,1,.8) # …

---

## [Q: automatically updating/detecting missed JLL packages updates](https://discourse.julialang.org/t/q-automatically-updating-detecting-missed-jll-packages-updates/81413)

<div class="topic-metadata">

**Author:** [@ImreSamu](https://discourse.julialang.org/u/ImreSamu)\
**Replies:** 4\
**Last updated:** [May 24, 2022, 2:21pm UTC](https://discourse.julialang.org/t/q-automatically-updating-detecting-missed-jll-packages-updates/81413 "2022-05-24T14:21:11Z")

</div>

context: Some JLL packages are not updated to the latest version so important (security) patches not used. hard to find these packages in the local environments. example: LibPQ\_jll ( PostgreSQL client) - based on v…

---

## [Freely moving agents in a GridSpace-like environment](https://discourse.julialang.org/t/freely-moving-agents-in-a-gridspace-like-environment/81586)

<div class="topic-metadata">

**Author:** [@Demlore](https://discourse.julialang.org/u/Demlore)\
**Replies:** 1\
**Last updated:** [May 24, 2022, 1:57pm UTC](https://discourse.julialang.org/t/freely-moving-agents-in-a-gridspace-like-environment/81586 "2022-05-24T13:57:03Z")

</div>

I am currently trying to implement a model similar to the model “Predator-prey dynamics” from the Example Zoo. My current issue is that i need freely moving agents in a space made out of square patches just like the e…

---

## [Looping constructs, construct equations, ModelingToolkit](https://discourse.julialang.org/t/looping-constructs-construct-equations-modelingtoolkit/81568)

<div class="topic-metadata">

**Author:** [@Rohan\_Rajagopal](https://discourse.julialang.org/u/Rohan_Rajagopal)\
**Replies:** 1\
**Last updated:** [May 24, 2022, 1:13pm UTC](https://discourse.julialang.org/t/looping-constructs-construct-equations-modelingtoolkit/81568 "2022-05-24T13:13:46Z")

</div>

Is it possible to define equations using looping constructs, or is there a “correct” way to implement the following systems of equations, N=3; @parameters μ ϵ η\_ω η\_a A β\[1:N\] ω\[1:N\] θ\[1:N, 1:N\] @variables z\[1:N^2+3\*N …

---

## [Faust.jl fails to precompile with Julia v1.7.2](https://discourse.julialang.org/t/faust-jl-fails-to-precompile-with-julia-v1-7-2/81573)

<div class="topic-metadata">

**Author:** [@sletz](https://discourse.julialang.org/u/sletz)\
**Replies:** 1\
**Last updated:** [May 24, 2022, 12:58pm UTC](https://discourse.julialang.org/t/faust-jl-fails-to-precompile-with-julia-v1-7-2/81573 "2022-05-24T12:58:56Z")

</div>

Faust.jl fails to compile with Julia v1.7.2 (tested on macOS): using Faust \[ Info: Precompiling Faust \[b0df9959-3f7b-4e37-9fbf-63cb195e8303\] ERROR: LoadError: TypeError: in cfunction method definition, expected Type, go…

---

## [First steps: Start Julia in a certain folder in VSCode](https://discourse.julialang.org/t/first-steps-start-julia-in-a-certain-folder-in-vscode/80822)

<div class="topic-metadata">

**Author:** [@BrianOConner](https://discourse.julialang.org/u/BrianOConner)\
**Replies:** 17\
**Last updated:** [May 24, 2022, 12:07pm UTC](https://discourse.julialang.org/t/first-steps-start-julia-in-a-certain-folder-in-vscode/80822 "2022-05-24T12:07:46Z")

</div>

Hi (sorry, first day here), I open a folder and get in the terminal just: PS D\\andSoOn\_theFolderPath \> To get to Julia (if one can say it like that) I have to run a lin of code of a program in my folder, what am I doin…

---

## [Unable to install PyCall on MacOS outside Julia shell](https://discourse.julialang.org/t/unable-to-install-pycall-on-macos-outside-julia-shell/81581)

<div class="topic-metadata">

**Author:** [@kerim](https://discourse.julialang.org/u/kerim)\
**Replies:** 0\
**Last updated:** [May 24, 2022, 12:30pm UTC](https://discourse.julialang.org/t/unable-to-install-pycall-on-macos-outside-julia-shell/81581 "2022-05-24T12:30:48Z")

</div>

Hi, MacOS 10.15, Julia 1.6.5 I installed Julia using jill. Then I’m trying to install PyCall using script: using Pkg; @info "Python executable used for PyCall: $(ARGS\[1\])" ENV\["PYTHON"\] = ARGS\[1\] Pkg.add("PyCall") P…

---

## [Standalone PackageCompiler app with Plots fails with GR\_jll error](https://discourse.julialang.org/t/standalone-packagecompiler-app-with-plots-fails-with-gr-jll-error/81507)

<div class="topic-metadata">

**Author:** [@ConnectedSystems](https://discourse.julialang.org/u/ConnectedSystems)\
**Replies:** 3\
**Last updated:** [May 24, 2022, 12:03pm UTC](https://discourse.julialang.org/t/standalone-packagecompiler-app-with-plots-fails-with-gr-jll-error/81507 "2022-05-24T12:03:41Z")

</div>

Putting together an app that displays a plot of results at the end. Unfortunately, the plot never displays at the end. Instead, there is an error message about GR\_jll, although I see it listed when it is compiling (see b…

---

## [Optimization computational time](https://discourse.julialang.org/t/optimization-computational-time/81558)

<div class="topic-metadata">

**Author:** [@O\_olalekan](https://discourse.julialang.org/u/O_olalekan)\
**Replies:** 2\
**Last updated:** [May 24, 2022, 11:50am UTC](https://discourse.julialang.org/t/optimization-computational-time/81558 "2022-05-24T11:50:31Z")

</div>

I read several materials on the computational time of optimization models. The MILP computational time has always been faster than the NLP formulation. I then stumbled on an article which got that the computational time …

---

## [Calling Julia from Python](https://discourse.julialang.org/t/calling-julia-from-python/36538)

<div class="topic-metadata">

**Author:** [@omi](https://discourse.julialang.org/u/omi)\
**Replies:** 4\
**Last updated:** [May 24, 2022, 11:38am UTC](https://discourse.julialang.org/t/calling-julia-from-python/36538 "2022-05-24T11:38:40Z")

</div>

I’m interested for working in julia for GSoC 20. For the same I am interested in calling julia functions from python.I am very new to julia but familiar with python. Will be eager to know how to get started…

---

## [How to plot ~10 billion datapoint time series efficiently?](https://discourse.julialang.org/t/how-to-plot-10-billion-datapoint-time-series-efficiently/81228)

<div class="topic-metadata">

**Author:** [@hk69](https://discourse.julialang.org/u/hk69)\
**Replies:** 47\
**Last updated:** [May 24, 2022, 11:26am UTC](https://discourse.julialang.org/t/how-to-plot-10-billion-datapoint-time-series-efficiently/81228 "2022-05-24T11:26:35Z")

</div>

Hi, I am relatively new to Julia. I have a physics model that I implemented in Julia. I solve the differential equations to track the orbit of two blackholes over a period of about 5 years with very small time step. My …

---

## [A simple model which I can't get Turing to fit to simulated data](https://discourse.julialang.org/t/a-simple-model-which-i-cant-get-turing-to-fit-to-simulated-data/81572)

<div class="topic-metadata">

**Author:** [@lgrozinger](https://discourse.julialang.org/u/lgrozinger)\
**Replies:** 1\
**Last updated:** [May 24, 2022, 11:12am UTC](https://discourse.julialang.org/t/a-simple-model-which-i-cant-get-turing-to-fit-to-simulated-data/81572 "2022-05-24T11:12:58Z")

</div>

Having just started with Turing, I am unable to understand why this model does not produce good results. using Turing using MCMCChains λ = Normal(0, 1) data = rand.(Poisson.(exp.(rand(λ, 2^16)))) @model function m(y, …

---

## [How to efficiently handle parallelism on a DistributedArray](https://discourse.julialang.org/t/how-to-efficiently-handle-parallelism-on-a-distributedarray/81098)

<div class="topic-metadata">

**Author:** [@ultrapoci](https://discourse.julialang.org/u/ultrapoci)\
**Replies:** 8\
**Last updated:** [May 24, 2022, 10:03am UTC](https://discourse.julialang.org/t/how-to-efficiently-handle-parallelism-on-a-distributedarray/81098 "2022-05-24T10:03:38Z")

</div>

I’m working with a DArray from DistributedArrays.jl. I want each process to work on its own part of the array independently, and access the rest of the array only when it needs a nearest neighbor which doesn’t reside in …

---

## [Writing documentation for a project with DrWatson](https://discourse.julialang.org/t/writing-documentation-for-a-project-with-drwatson/81554)

<div class="topic-metadata">

**Author:** [@roi.holtzman](https://discourse.julialang.org/u/roi.holtzman)\
**Replies:** 4\
**Last updated:** [May 24, 2022, 9:36am UTC](https://discourse.julialang.org/t/writing-documentation-for-a-project-with-drwatson/81554 "2022-05-24T09:36:40Z")

</div>

I have a DrWatson project for which I want to write some documentation. I was wondering if I can use Documenter.jl even though this is a project and not a package. Are there any tips for writing documentation for a pro…

---

## [Why exactly is promote(1:2,\[1,2\]) designed to throw an error?](https://discourse.julialang.org/t/why-exactly-is-promote-1-2-1-2-designed-to-throw-an-error/81555)

<div class="topic-metadata">

**Author:** [@skraemer](https://discourse.julialang.org/u/skraemer)\
**Replies:** 2\
**Last updated:** [May 24, 2022, 9:08am UTC](https://discourse.julialang.org/t/why-exactly-is-promote-1-2-1-2-designed-to-throw-an-error/81555 "2022-05-24T09:08:29Z")

</div>

The call promote(1:2,\[1,2\]) throws an error. As far as I understand, this is because on the one hand promote\_type(UnitRange{Int64},Array{Int64}) returns AbstractArray{Int64,N} where N, whereas on the other hand both conv…

---

## [Push! not working as expected](https://discourse.julialang.org/t/push-not-working-as-expected/81563)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 2\
**Last updated:** [May 24, 2022, 9:32am UTC](https://discourse.julialang.org/t/push-not-working-as-expected/81563 "2022-05-24T09:32:07Z")

</div>

What am I doing wrong here: using KiteUtils s=demo\_state(7) vec=Vector{SysState{7}}\[\] typeof(s) Output SysState{7} Now I try to push s into the vector vec julia\> push!(vec,s) ERROR: MethodError: Cannot \`convert\` an …

---

## [Time to reach steady-state (ODEProblem)](https://discourse.julialang.org/t/time-to-reach-steady-state-odeproblem/81501)

<div class="topic-metadata">

**Author:** [@SiddhantDeshmukh](https://discourse.julialang.org/u/SiddhantDeshmukh)\
**Replies:** 1\
**Last updated:** [May 24, 2022, 8:26am UTC](https://discourse.julialang.org/t/time-to-reach-steady-state-odeproblem/81501 "2022-05-24T08:26:52Z")

</div>

Hello, I would like to find the point at which all variables in a given ODESystem reach a steady-state, i.e. their relative change is below some defined threshold. I came across SteadyStateProblem to calculate a steady-…

---

## [ERROR: UndefVarError: parameters not defined](https://discourse.julialang.org/t/error-undefvarerror-parameters-not-defined/81385)

<div class="topic-metadata">

**Author:** [@Hupdup](https://discourse.julialang.org/u/Hupdup)\
**Replies:** 6\
**Last updated:** [May 24, 2022, 7:50am UTC](https://discourse.julialang.org/t/error-undefvarerror-parameters-not-defined/81385 "2022-05-24T07:50:06Z")

</div>

Hi, I want to do some reinforcement learning in Julia, but when I want to perform my action, it always gives me this error. do you know what i should do? I already downloaded the latest version of the packages. functio…

---

## [Current Status of ppc64le Support](https://discourse.julialang.org/t/current-status-of-ppc64le-support/47279)

<div class="topic-metadata">

**Author:** [@michaela](https://discourse.julialang.org/u/michaela)\
**Replies:** 9\
**Last updated:** [May 24, 2022, 7:41am UTC](https://discourse.julialang.org/t/current-status-of-ppc64le-support/47279 "2022-05-24T07:41:42Z")

</div>

I was wondering what the status of Julia support for the ppc64le architecture is for the most recent versions of Julia (v1.5.1+). I saw in this GitHub Issue discussion that there were talks of working with IBM to make th…

---

## [Ever increasing time for garbage collection](https://discourse.julialang.org/t/ever-increasing-time-for-garbage-collection/81543)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 7\
**Last updated:** [May 23, 2022, 11:10pm UTC](https://discourse.julialang.org/t/ever-increasing-time-for-garbage-collection/81543 "2022-05-23T23:10:55Z")

</div>

Hello, I have a simulation that is running in real-time for an undefined period of time (until you stop it). I solve my equation system every 50ms. For one solution about 800 calls to the inner residual function are ne…

---

## [How to save output from GraphViz.jl to pdf?](https://discourse.julialang.org/t/how-to-save-output-from-graphviz-jl-to-pdf/81476)

<div class="topic-metadata">

**Author:** [@Norman](https://discourse.julialang.org/u/Norman)\
**Replies:** 4\
**Last updated:** [May 23, 2022, 10:47pm UTC](https://discourse.julialang.org/t/how-to-save-output-from-graphviz-jl-to-pdf/81476 "2022-05-23T22:47:12Z")

</div>

Hi, Could someone show an example of printing the output generated from GraphViz.jl to a pdf file? Let’s say just use the example below. Thank you! dot""" graph graphname { // The label attribute can be used to ch…

---

## [Error when trying to specify the initial simplex of Nelder Mead method in GalacticOptim.jl](https://discourse.julialang.org/t/error-when-trying-to-specify-the-initial-simplex-of-nelder-mead-method-in-galacticoptim-jl/81506)

<div class="topic-metadata">

**Author:** [@martinmestre](https://discourse.julialang.org/u/martinmestre)\
**Replies:** 10\
**Last updated:** [May 23, 2022, 10:22pm UTC](https://discourse.julialang.org/t/error-when-trying-to-specify-the-initial-simplex-of-nelder-mead-method-in-galacticoptim-jl/81506 "2022-05-23T22:22:20Z")

</div>

Hello, I would need help with the following error when trying specify the a,b parameters of the initial simplex constructor. I gives the same error even if I call the constructor without arguments. I have Julia 1.7.2. …

---

## [\[ANN\] ProfileCanvas.jl](https://discourse.julialang.org/t/ann-profilecanvas-jl/80761)

<div class="topic-metadata">

**Author:** [@pfitzseb](https://discourse.julialang.org/u/pfitzseb)\
**Replies:** 7\
**Last updated:** [May 23, 2022, 9:58pm UTC](https://discourse.julialang.org/t/ann-profilecanvas-jl/80761 "2022-05-23T21:58:25Z")

</div>

ProfileCanvas.jl ProfileCanvas.jl is a drop-in replacement for ProfileView.jl and ProfileSVG.jl. It exposes the HTML canvas based profile viewer UI used by the Julia extension for VS Code in the REPL and environments th…

---

## [Use add\_to\_expression!() for multi-dimension expressions](https://discourse.julialang.org/t/use-add-to-expression-for-multi-dimension-expressions/81532)

<div class="topic-metadata">

**Author:** [@xuqingyu](https://discourse.julialang.org/u/xuqingyu)\
**Replies:** 3\
**Last updated:** [May 23, 2022, 9:52pm UTC](https://discourse.julialang.org/t/use-add-to-expression-for-multi-dimension-expressions/81532 "2022-05-23T21:52:51Z")

</div>

Hi all, May I have your suggestions on how to use add\_to\_expression!() to add one multi-dimension expressions to another? Say I have an expression A with dimension (n x m), and an expression B with dimension (n x m). …

---

## [How can I transform this matlab code into Julia](https://discourse.julialang.org/t/how-can-i-transform-this-matlab-code-into-julia/81351)

<div class="topic-metadata">

**Author:** [@Raymond](https://discourse.julialang.org/u/Raymond)\
**Replies:** 28\
**Last updated:** [May 23, 2022, 8:47pm UTC](https://discourse.julialang.org/t/how-can-i-transform-this-matlab-code-into-julia/81351 "2022-05-23T20:47:55Z")

</div>

\>\> val = zeros(3, 3); \>\> row = zeros(3, 3); \>\> A = \[1 2 3; 6 5 1; 1 7 4\]; \[val(1, :), row(1, :)\] = max(A) val = 6 7 4 0 0 0 0 0 0 row = 2 3 3 0 0 0 …

---

## [What is the equivalence to Matlab code "sparse(1:3, \[1 3 5\], \[11 12 13\])" in Julia](https://discourse.julialang.org/t/what-is-the-equivalence-to-matlab-code-sparse-1-3-1-3-5-11-12-13-in-julia/81537)

<div class="topic-metadata">

**Author:** [@Amro](https://discourse.julialang.org/u/Amro)\
**Replies:** 2\
**Last updated:** [May 23, 2022, 8:34pm UTC](https://discourse.julialang.org/t/what-is-the-equivalence-to-matlab-code-sparse-1-3-1-3-5-11-12-13-in-julia/81537 "2022-05-23T20:34:51Z")

</div>

What is equivalent to the below Matlab code in Julia. Which creates a sparse matrix of 1:3 rows and fills the elements in columns \[1 3 5\] (corresponding to rows 1:3) by \[11 12 13\] \>\> sparse(1:3, \[1 3 5\], \[11 12 13\]) an…

---

## [Function \`confusion\_matrix \` in MLJ always fails](https://discourse.julialang.org/t/function-confusion-matrix-in-mlj-always-fails/81521)

<div class="topic-metadata">

**Author:** [@tiZ](https://discourse.julialang.org/u/tiZ)\
**Replies:** 4\
**Last updated:** [May 23, 2022, 7:57pm UTC](https://discourse.julialang.org/t/function-confusion-matrix-in-mlj-always-fails/81521 "2022-05-23T19:57:49Z")

</div>

Hello, I try to caculate a confusion matrix in Julia, but I meet some ERROR and it is hard for me to debug, any suggestion? Thanks you. here is my code using MLJ, CategoricalArrays # Status \`~/.julia/environments/v1…

---

## [Julia internship in Massachusetts](https://discourse.julialang.org/t/julia-internship-in-massachusetts/81534)

<div class="topic-metadata">

**Author:** [@drhagen](https://discourse.julialang.org/u/drhagen)\
**Replies:** 0\
**Last updated:** [May 23, 2022, 8:02pm UTC](https://discourse.julialang.org/t/julia-internship-in-massachusetts/81534 "2022-05-23T20:02:22Z")

</div>

Applied BioMath is looking to hire a Julia intern to convert our C library for ODE simulations into Julia and test the various ODE solvers available in Julia on our models. At Applied BioMath, we do a lot of simulations…

---

## [Passing struct with Union type to other function](https://discourse.julialang.org/t/passing-struct-with-union-type-to-other-function/81482)

<div class="topic-metadata">

**Author:** [@yhchang96](https://discourse.julialang.org/u/yhchang96)\
**Replies:** 6\
**Last updated:** [May 23, 2022, 8:01pm UTC](https://discourse.julialang.org/t/passing-struct-with-union-type-to-other-function/81482 "2022-05-23T20:01:45Z")

</div>

I’m pretty new to Julia so I might have missed something pretty elementary. I have defined the following struct which contains some parameters with default values. @with\_kw struct Par1 D::Union{Float64, VecOrMat{Fl…

---

## [Does Makie.save("name", scene) also save the legends on the plot automatically?](https://discourse.julialang.org/t/does-makie-save-name-scene-also-save-the-legends-on-the-plot-automatically/81492)

<div class="topic-metadata">

**Author:** [@Nihilol1](https://discourse.julialang.org/u/Nihilol1)\
**Replies:** 6\
**Last updated:** [May 23, 2022, 8:00pm UTC](https://discourse.julialang.org/t/does-makie-save-name-scene-also-save-the-legends-on-the-plot-automatically/81492 "2022-05-23T20:00:27Z")

</div>

My simplified code looks as follows: using GLMakie fig1 = Figure() ax1 = Axis(fig1\[1,1\], xlabel = “What”, ylabel = “is going on”) GLMakie.scatter!(ax1, xvalues, yvalues, makersize = 4, color = colours, label = “pleas…

[Previous page](https://discourse.julialang.org/latest.md?page=1030)

[Next page](https://discourse.julialang.org/latest.md?page=1032)