# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1727

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

**Page:** 1728

---

## [Where is julia specific documentation for Jupyter notebook?](https://discourse.julialang.org/t/where-is-julia-specific-documentation-for-jupyter-notebook/40749)

<div class="topic-metadata">

**Author:** [@devel-chm](https://discourse.julialang.org/u/devel-chm)\
**Replies:** 11\
**Last updated:** [June 5, 2020, 4:12pm UTC](https://discourse.julialang.org/t/where-is-julia-specific-documentation-for-jupyter-notebook/40749 "2020-06-05T16:12:23Z")

</div>

I have been using the Jupyter notebook interface to learn Julia and to document what I have learned and done/fixed. I had started with the julia REPL from a mintty terminal (cygwin) on win7 but was not able to iterate a…

---

## [Error: Installing Juno in Atom](https://discourse.julialang.org/t/error-installing-juno-in-atom/25394)

<div class="topic-metadata">

**Author:** [@Nguyen\_Huyen](https://discourse.julialang.org/u/Nguyen_Huyen)\
**Replies:** 7\
**Last updated:** [June 5, 2020, 3:54pm UTC](https://discourse.julialang.org/t/error-installing-juno-in-atom/25394 "2020-06-05T15:54:10Z")

</div>

I got the following error while installing JuliaJuno in Atom Juno: Error installing package ink Please check your internet connection, or report this to http://discuss.junolab.org and we’ll try to help. ––– Error:…

---

## [How to save values from a differential equation not part of initial conditions (u) and then graph them?](https://discourse.julialang.org/t/how-to-save-values-from-a-differential-equation-not-part-of-initial-conditions-u-and-then-graph-them/40183)

<div class="topic-metadata">

**Author:** [@HelgavonLichtenstein](https://discourse.julialang.org/u/HelgavonLichtenstein)\
**Replies:** 17\
**Last updated:** [June 5, 2020, 3:46pm UTC](https://discourse.julialang.org/t/how-to-save-values-from-a-differential-equation-not-part-of-initial-conditions-u-and-then-graph-them/40183 "2020-06-05T15:46:38Z")

</div>

Hello, I have a food web that is driven by differential equations, that includes changes in plants, animals, and boat ‘population’. There are variables such as amount of fish harvested (catch\_F) and fish price (fish\_pri…

---

## [(Not) concatenating arrays](https://discourse.julialang.org/t/not-concatenating-arrays/40803)

<div class="topic-metadata">

**Author:** [@sparrowhawk](https://discourse.julialang.org/u/sparrowhawk)\
**Replies:** 3\
**Last updated:** [June 5, 2020, 1:54pm UTC](https://discourse.julialang.org/t/not-concatenating-arrays/40803 "2020-06-05T13:54:21Z")

</div>

I have a large Vector{Float64} called x, a few elements of which remain unchanged within a loop. I would like the remaining elements to reflect the values in another array b, before passing on to a function within the lo…

---

## [Parallel reductions on CPUs with different speeds](https://discourse.julialang.org/t/parallel-reductions-on-cpus-with-different-speeds/40722)

<div class="topic-metadata">

**Author:** [@hcarlsso](https://discourse.julialang.org/u/hcarlsso)\
**Replies:** 6\
**Last updated:** [June 5, 2020, 1:34pm UTC](https://discourse.julialang.org/t/parallel-reductions-on-cpus-with-different-speeds/40722 "2020-06-05T13:34:02Z")

</div>

I am looking for how to “load balance” parallel reduction on multiple CPUs that have different speeds. The following snippet illustrates the problem: using Distributed addprocs(3) res = @time @distributed (+) for (t, n…

---

## [Mac or Windows for better Julia experience?](https://discourse.julialang.org/t/mac-or-windows-for-better-julia-experience/40404)

<div class="topic-metadata">

**Author:** [@Alvaro\_Jose\_Gonzalez](https://discourse.julialang.org/u/Alvaro_Jose_Gonzalez)\
**Replies:** 19\
**Last updated:** [June 5, 2020, 12:45pm UTC](https://discourse.julialang.org/t/mac-or-windows-for-better-julia-experience/40404 "2020-06-05T12:45:19Z")

</div>

Hello All, I have been working with Julia on Windows for about 3 years, more specifically with JuMP for energy systems optimization. There has always been a pain to install some packages and some “unusual tricks” are r…

---

## [Notes on GPU Programming with Julia](https://discourse.julialang.org/t/notes-on-gpu-programming-with-julia/40678)

<div class="topic-metadata">

**Author:** [@eaubanel](https://discourse.julialang.org/u/eaubanel)\
**Replies:** 2\
**Last updated:** [June 5, 2020, 12:30pm UTC](https://discourse.julialang.org/t/notes-on-gpu-programming-with-julia/40678 "2020-06-05T12:30:09Z")

</div>

I’m planning to use Julia as the language in my intro to parallel computing course next year. My personal favorite type of parallel programming is on GPUs, so I’ve started with some notes on GPU programming with Julia, w…

---

## [How to host the documentation generated by Documenter.jl / Travis?](https://discourse.julialang.org/t/how-to-host-the-documentation-generated-by-documenter-jl-travis/40809)

<div class="topic-metadata">

**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 1\
**Last updated:** [June 5, 2020, 12:15pm UTC](https://discourse.julialang.org/t/how-to-host-the-documentation-generated-by-documenter-jl-travis/40809 "2020-06-05T12:15:41Z")

</div>

I am trying to build the documentation for my package. I did follow the instruction on Hosting Documentation · Documenter.jl and it seems that the travis-ci job is done correctly (I have a nice reassuring green tick on …

---

## [Unclear sentence in Performance Tips doc page](https://discourse.julialang.org/t/unclear-sentence-in-performance-tips-doc-page/40758)

<div class="topic-metadata">

**Author:** [@natema](https://discourse.julialang.org/u/natema)\
**Replies:** 5\
**Last updated:** [June 5, 2020, 12:01pm UTC](https://discourse.julialang.org/t/unclear-sentence-in-performance-tips-doc-page/40758 "2020-06-05T12:01:48Z")

</div>

In the section Access arrays in memory order, along columns, there is the final sentence (Of course, if you just do f.(x) then it is as fast as fdot(x) in this example, but in many contexts it is more convenient to jus…

---

## [Accessing the JSON part of this HTTP response](https://discourse.julialang.org/t/accessing-the-json-part-of-this-http-response/40805)

<div class="topic-metadata">

**Author:** [@Nash](https://discourse.julialang.org/u/Nash)\
**Replies:** 2\
**Last updated:** [June 5, 2020, 11:44am UTC](https://discourse.julialang.org/t/accessing-the-json-part-of-this-http-response/40805 "2020-06-05T11:44:08Z")

</div>

I have used the code provided here (link to Stackoverflow) to access the Betfair API. And things work; a response is obtained. However, I would now like to use the data that I have retrieved, and that is what I cannot f…

---

## [Problem LightGraphs creating graphs and accessing vertices LightGraphs](https://discourse.julialang.org/t/problem-lightgraphs-creating-graphs-and-accessing-vertices-lightgraphs/40804)

<div class="topic-metadata">

**Author:** [@Florent\_Poux](https://discourse.julialang.org/u/Florent_Poux)\
**Replies:** 1\
**Last updated:** [June 5, 2020, 11:25am UTC](https://discourse.julialang.org/t/problem-lightgraphs-creating-graphs-and-accessing-vertices-lightgraphs/40804 "2020-06-05T11:25:49Z")

</div>

Hi, I struggle to have a reliable behavior using Lightgraphs. Yesterday, I could plot some graphs based on some arrays I had, but impossible to use the command “vertices(G)” for example (returned: UndefVarError: vertice…

---

## [Contourplot on a Sphere in Makie.jl](https://discourse.julialang.org/t/contourplot-on-a-sphere-in-makie-jl/40801)

<div class="topic-metadata">

**Author:** [@kellertuer](https://discourse.julialang.org/u/kellertuer)\
**Replies:** 0\
**Last updated:** [June 5, 2020, 10:37am UTC](https://discourse.julialang.org/t/contourplot-on-a-sphere-in-makie-jl/40801 "2020-06-05T10:37:16Z")

</div>

I recently tried to get started with Makie, since I love the approach and it seems to be fairly huge in features. However, I sometimes struggle in details I have some data on a sphere, let’s say I have a function F defi…

---

## [Backtrace in Tasks](https://discourse.julialang.org/t/backtrace-in-tasks/40713)

<div class="topic-metadata">

**Author:** [@Impressium](https://discourse.julialang.org/u/Impressium)\
**Replies:** 7\
**Last updated:** [June 5, 2020, 9:37am UTC](https://discourse.julialang.org/t/backtrace-in-tasks/40713 "2020-06-05T09:37:52Z")

</div>

At work I have to program concurrently. I really love programming in Julia but one thing that annoys me are the backtrace in tasks. t = @async begin for i in 1:10 end error() end t |\> dump julia\> Task…

---

## [Difference between @view and view](https://discourse.julialang.org/t/difference-between-view-and-view/40798)

<div class="topic-metadata">

**Author:** [@sparrowhawk](https://discourse.julialang.org/u/sparrowhawk)\
**Replies:** 2\
**Last updated:** [June 5, 2020, 9:27am UTC](https://discourse.julialang.org/t/difference-between-view-and-view/40798 "2020-06-05T09:27:38Z")

</div>

If A = \[1,2; 3 4\] What is the difference between b = view(A, :, 1) and b = @view A\[:,1\] Is the macro form just shorthand for the other? Thanks

---

## [Suggestion for concept maps](https://discourse.julialang.org/t/suggestion-for-concept-maps/62752)

<div class="topic-metadata">

**Author:** [@Ramayya](https://discourse.julialang.org/u/Ramayya)\
**Replies:** 1\
**Last updated:** [June 5, 2020, 8:32am UTC](https://discourse.julialang.org/t/suggestion-for-concept-maps/62752 "2020-06-05T08:32:32Z")

</div>

Where does one start typing to start a new topic? Since Julia is undergoing rapid development, may I suggest that Julia Concept Maps https://cmap.ihmc.us be developed and put them on the Home Pages of Julia, and expand t…

---

## [OutOfMemory(): How to inspect environment memory?](https://discourse.julialang.org/t/outofmemory-how-to-inspect-environment-memory/40738)

<div class="topic-metadata">

**Author:** [@HenriDeh](https://discourse.julialang.org/u/HenriDeh)\
**Replies:** 7\
**Last updated:** [June 5, 2020, 8:12am UTC](https://discourse.julialang.org/t/outofmemory-how-to-inspect-environment-memory/40738 "2020-06-05T08:12:43Z")

</div>

I run into an OutOfMemory error when running an algorithm several times. Everything happens inside functions so I don’t understand why and I would like to inspect what has accumulated in the memory. The error is triggere…

---

## [How to interact with student code](https://discourse.julialang.org/t/how-to-interact-with-student-code/40615)

<div class="topic-metadata">

**Author:** [@leclere](https://discourse.julialang.org/u/leclere)\
**Replies:** 7\
**Last updated:** [June 5, 2020, 7:21am UTC](https://discourse.julialang.org/t/how-to-interact-with-student-code/40615 "2020-06-05T07:21:37Z")

</div>

Hello ! I have kind of an awkward question : what would be the best way to interact with student code in a “competitive” form. Let me explain : I plan on making a competition on optimal control. The idea is to ask the s…

---

## [“using” expression not at top level](https://discourse.julialang.org/t/using-expression-not-at-top-level/40657)

<div class="topic-metadata">

**Author:** [@stv1314](https://discourse.julialang.org/u/stv1314)\
**Replies:** 4\
**Last updated:** [June 5, 2020, 6:55am UTC](https://discourse.julialang.org/t/using-expression-not-at-top-level/40657 "2020-06-05T06:55:11Z")

</div>

Can any body tell me what’s wrong with this?

---

## [Include a C++ function in a Stan code](https://discourse.julialang.org/t/include-a-c-function-in-a-stan-code/40782)

<div class="topic-metadata">

**Author:** [@99dB](https://discourse.julialang.org/u/99dB)\
**Replies:** 2\
**Last updated:** [June 5, 2020, 4:11am UTC](https://discourse.julialang.org/t/include-a-c-function-in-a-stan-code/40782 "2020-06-05T04:11:39Z")

</div>

Dear all, I need to include a C++ function in a stan code but I don’t know how I can do it. The function is remainder and then I include the associated library but I get this error: SystemError: opening file "\<cmath\>"…

---

## [How Julia call Pybind11 code?](https://discourse.julialang.org/t/how-julia-call-pybind11-code/40787)

<div class="topic-metadata">

**Author:** [@agdkyang](https://discourse.julialang.org/u/agdkyang)\
**Replies:** 1\
**Last updated:** [June 5, 2020, 3:51am UTC](https://discourse.julialang.org/t/how-julia-call-pybind11-code/40787 "2020-06-05T03:51:15Z")

</div>

Pybind11 code : #include \<pybind11/embed.h\> #include namespace py = pybind11; extern “C”{ int init() { py::scoped\_interpreter python; auto math = py::module::import(“math”); double root\_two = math.attr(“sqrt”)(2…

---

## [Best performance using dictionaries, functions and modules](https://discourse.julialang.org/t/best-performance-using-dictionaries-functions-and-modules/40673)

<div class="topic-metadata">

**Author:** [@Joey](https://discourse.julialang.org/u/Joey)\
**Replies:** 8\
**Last updated:** [June 5, 2020, 3:39am UTC](https://discourse.julialang.org/t/best-performance-using-dictionaries-functions-and-modules/40673 "2020-06-05T03:39:20Z")

</div>

Hi everyone, I’m currently working on a program and need some help for better performance. As I switched from MATLAB to Julia, I don’t know if I am writting in a good way. I tried to write it similarly to MATLAB’s fashi…

---

## [Need help with Variational Inference](https://discourse.julialang.org/t/need-help-with-variational-inference/40789)

<div class="topic-metadata">

**Author:** [@Farlein](https://discourse.julialang.org/u/Farlein)\
**Replies:** 0\
**Last updated:** [June 5, 2020, 3:08am UTC](https://discourse.julialang.org/t/need-help-with-variational-inference/40789 "2020-06-05T03:08:28Z")

</div>

Hi there, I have been recently attracted to variational inference. I like the idea to link Bayesian modeling with optimization. I like its uni modal approximation to the parameters in a model (by assuming the variationa…

---

## [Unable to save Unitful unit into a JLD file](https://discourse.julialang.org/t/unable-to-save-unitful-unit-into-a-jld-file/40706)

<div class="topic-metadata">

**Author:** [@PeterSimon](https://discourse.julialang.org/u/PeterSimon)\
**Replies:** 9\
**Last updated:** [June 5, 2020, 2:51am UTC](https://discourse.julialang.org/t/unable-to-save-unitful-unit-into-a-jld-file/40706 "2020-06-05T02:51:38Z")

</div>

I am writing an application where the user may choose the length unit from among those provided by the Unitful package. I create a struct where the chosen length unit is stored in one of the fields. I found that when I…

---

## [.julia directory shared by different versions](https://discourse.julialang.org/t/julia-directory-shared-by-different-versions/40770)

<div class="topic-metadata">

**Author:** [@pauljurczak](https://discourse.julialang.org/u/pauljurczak)\
**Replies:** 2\
**Last updated:** [June 5, 2020, 1:52am UTC](https://discourse.julialang.org/t/julia-directory-shared-by-different-versions/40770 "2020-06-05T01:52:43Z")

</div>

I have 2 versions of Julia, but as far as I can tell they share /home/paul/.julia working directory. Is that OK? Should I configure something differently? It seems to be working, but maybe there are some gotchas. If it’…

---

## [Relation between Makie.jl and Plots.jl](https://discourse.julialang.org/t/relation-between-makie-jl-and-plots-jl/40731)

<div class="topic-metadata">

**Author:** [@jamblejoe](https://discourse.julialang.org/u/jamblejoe)\
**Replies:** 2\
**Last updated:** [June 4, 2020, 11:51pm UTC](https://discourse.julialang.org/t/relation-between-makie-jl-and-plots-jl/40731 "2020-06-04T23:51:42Z")

</div>

There was a similar question asked a year ago, here Current state of the relationship between Plots and Makie. I am just curious of what is the relation between the two plotting libraries at the moment. I know that Plot…

---

## [Meaning and alternatives to "undef" when initializing vectors](https://discourse.julialang.org/t/meaning-and-alternatives-to-undef-when-initializing-vectors/40759)

<div class="topic-metadata">

**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 11\
**Last updated:** [June 4, 2020, 11:00pm UTC](https://discourse.julialang.org/t/meaning-and-alternatives-to-undef-when-initializing-vectors/40759 "2020-06-04T23:00:36Z")

</div>

It is not that I have problems using this, but particularly for didactic purposes I feel I need a clarification: Whenever I initialize a vector of, lets say, integers, using, for example x = Vector{Int64}(undef,3) The…

---

## [DataFrames Package: \`getindex(df::DataFrame, col\_inds::Union{AbstractVector, Regex, Not})\` is deprecated](https://discourse.julialang.org/t/dataframes-package-getindex-df-dataframe-col-inds-union-abstractvector-regex-not-is-deprecated/40744)

<div class="topic-metadata">

**Author:** [@aebk2015](https://discourse.julialang.org/u/aebk2015)\
**Replies:** 8\
**Last updated:** [June 4, 2020, 10:53pm UTC](https://discourse.julialang.org/t/dataframes-package-getindex-df-dataframe-col-inds-union-abstractvector-regex-not-is-deprecated/40744 "2020-06-04T22:53:22Z")

</div>

I just started reading Julia for Machine Learning. and I am getting a series of deprecated warning just from the DataFrames package: The dataset the book uses for this example has to do with the strength of Wi-Fi sign…

---

## [VS Code Julia version configuration issue](https://discourse.julialang.org/t/vs-code-julia-version-configuration-issue/40767)

<div class="topic-metadata">

**Author:** [@pauljurczak](https://discourse.julialang.org/u/pauljurczak)\
**Replies:** 3\
**Last updated:** [June 4, 2020, 10:51pm UTC](https://discourse.julialang.org/t/vs-code-julia-version-configuration-issue/40767 "2020-06-04T22:51:11Z")

</div>

I have Julia 1.4.1 and 1.5.0 beta installed. paul@extra:~/apps$ dir julia-1.4.1 julia-1.5.0-beta1 1.5 beta is on my path: paul@extra:~$ echo $PATH /opt/ros/melodic/bin:/home/paul/.local/bin:/usr/local/sbin:/usr/local…

---

## [ODE: no method matching similar](https://discourse.julialang.org/t/ode-no-method-matching-similar/40764)

<div class="topic-metadata">

**Author:** [@99dB](https://discourse.julialang.org/u/99dB)\
**Replies:** 6\
**Last updated:** [June 4, 2020, 9:57pm UTC](https://discourse.julialang.org/t/ode-no-method-matching-similar/40764 "2020-06-04T21:57:29Z")

</div>

Hi All, I try to compile an ODE model of 1 variable u but I need an if statement based on t. like something: function dudt!(du,u,p,t) if rem(t,10) \< 5 pp = p\[1\]\*t; end du = pp\*u end But I get the following message: M…

---

## [AMD support is understated?](https://discourse.julialang.org/t/amd-support-is-understated/40152)

<div class="topic-metadata">

**Author:** [@Matt\_Davis](https://discourse.julialang.org/u/Matt_Davis)\
**Replies:** 14\
**Last updated:** [June 4, 2020, 7:52pm UTC](https://discourse.julialang.org/t/amd-support-is-understated/40152 "2020-06-04T19:52:04Z")

</div>

I’ve seen a lot of posts being a little down on support for AMD gpus in Julia. There’s no doubt that the CUDA stack is more mature, but the OpenCL stack seems pretty good. Between OpenCL.jl, CLBlast.jl, and ArrayFire.jl,…

[Previous page](https://discourse.julialang.org/latest.md?page=1726)

[Next page](https://discourse.julialang.org/latest.md?page=1728)