# Latest

**URL:** https://discourse.julialang.org/latest.md?page=958

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

**Page:** 959

---

## [Let-in macro](https://discourse.julialang.org/t/let-in-macro/85431)

<div class="topic-metadata">

**Author:** [@jar1](https://discourse.julialang.org/u/jar1)\
**Replies:** 6\
**Last updated:** [August 8, 2022, 1:03pm UTC](https://discourse.julialang.org/t/let-in-macro/85431 "2022-08-08T13:03:29Z")

</div>

I want a macro like this: @let begin a = 1 b = 2 in y = a + b z = a - b end defines in the containing scope y and z in terms of a and b, without defining a and b in the containing scope. How can I do this?

---

## [Dateformat Makie](https://discourse.julialang.org/t/dateformat-makie/85381)

<div class="topic-metadata">

**Author:** [@jar1](https://discourse.julialang.org/u/jar1)\
**Replies:** 2\
**Last updated:** [August 8, 2022, 12:55pm UTC](https://discourse.julialang.org/t/dateformat-makie/85381 "2022-08-08T12:55:31Z")

</div>

In AoG I’m trying to do draw(;axis=(;xtickformat=dateformat"yyyy-mm")) . How can I get what I want?

---

## [How can I get the cookies from an HTTP response?](https://discourse.julialang.org/t/how-can-i-get-the-cookies-from-an-http-response/85454)

<div class="topic-metadata">

**Author:** [@mkjohnson](https://discourse.julialang.org/u/mkjohnson)\
**Replies:** 4\
**Last updated:** [August 8, 2022, 12:41pm UTC](https://discourse.julialang.org/t/how-can-i-get-the-cookies-from-an-http-response/85454 "2022-08-08T12:41:20Z")

</div>

I’m working with an API where I’m trying to grab one of the cookies from the response of a POST request. Coming from R - with the httr package, I can do something like this because cookies is a field in the response, mu…

---

## [Type hierarchy within Clang.jl](https://discourse.julialang.org/t/type-hierarchy-within-clang-jl/85451)

<div class="topic-metadata">

**Author:** [@freeman](https://discourse.julialang.org/u/freeman)\
**Replies:** 1\
**Last updated:** [August 8, 2022, 12:33pm UTC](https://discourse.julialang.org/t/type-hierarchy-within-clang-jl/85451 "2022-08-08T12:33:03Z")

</div>

I’m using Clang.jl to automatically generate julia wrappers over C structs, lets call them MyType1, MyType2, etc: struct MyType1 # generated by Clang.jl end struct MyType2 # generated by Clang.jl end However, t…

---

## [Juliad and julias, wrappers to DaemonMode and -J sysimage for quicker Linux/Cygwin scripts](https://discourse.julialang.org/t/juliad-and-julias-wrappers-to-daemonmode-and-j-sysimage-for-quicker-linux-cygwin-scripts/76690)

<div class="topic-metadata">

**Author:** [@jdad](https://discourse.julialang.org/u/jdad)\
**Replies:** 3\
**Last updated:** [August 8, 2022, 11:00am UTC](https://discourse.julialang.org/t/juliad-and-julias-wrappers-to-daemonmode-and-j-sysimage-for-quicker-linux-cygwin-scripts/76690 "2022-08-08T11:00:55Z")

</div>

FWIW, as an old linuxer, I have created for my own usage two scripts to facilitate the use of either sysimage or DaermonMode.jl to get faster frequently used scripts (=faster TTFX, Time to First X). Sorry, I have done th…

---

## [Intersection Symbol in Latex with PyPlotJS](https://discourse.julialang.org/t/intersection-symbol-in-latex-with-pyplotjs/85462)

<div class="topic-metadata">

**Author:** [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)\
**Replies:** 6\
**Last updated:** [August 8, 2022, 7:49am UTC](https://discourse.julialang.org/t/intersection-symbol-in-latex-with-pyplotjs/85462 "2022-08-08T07:49:39Z")

</div>

Hi all, I am playing around by creating venn diagram today, I want to know why I can’t make the intersection symbol appeared? Is it impossible? Thanks Here is the code: using PlotlyJS, LaTeXStrings # Create scatter t…

---

## [Related or linked structures](https://discourse.julialang.org/t/related-or-linked-structures/85463)

<div class="topic-metadata">

**Author:** [@Lincoln\_Hannah](https://discourse.julialang.org/u/Lincoln_Hannah)\
**Replies:** 0\
**Last updated:** [August 8, 2022, 7:45am UTC](https://discourse.julialang.org/t/related-or-linked-structures/85463 "2022-08-08T07:45:46Z")

</div>

Is it possible to connect data structures, similar to Primary-Key Foreign-Key connections in a relational database? One way could be to have a type similar to enum that would limit a field to a given set of values. Usi…

---

## [Performance of creating a demo dataset](https://discourse.julialang.org/t/performance-of-creating-a-demo-dataset/85441)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 7\
**Last updated:** [August 8, 2022, 2:56am UTC](https://discourse.julialang.org/t/performance-of-creating-a-demo-dataset/85441 "2022-08-08T02:56:38Z")

</div>

I have the following code: using InMemoryDatasets function demo\_data() ds = Dataset(time=0.0, d1=10, d2=20, d3=30) time = 0.1 for i in 1:100000 if i == 5 d1 = missing else …

---

## [Startup without $HOME on AWS](https://discourse.julialang.org/t/startup-without-home-on-aws/85452)

<div class="topic-metadata">

**Author:** [@sparrowhawk](https://discourse.julialang.org/u/sparrowhawk)\
**Replies:** 1\
**Last updated:** [August 8, 2022, 1:39am UTC](https://discourse.julialang.org/t/startup-without-home-on-aws/85452 "2022-08-08T01:39:17Z")

</div>

Hi all, I’m trying to run Julia on Amazon Workspaces, where all users at our workshop can simply spin up Julia and VSCode on a virtual 8 core Windows 10 machine. However, every time I spin up a new workspace, the windows…

---

## ["add Plots" giving error](https://discourse.julialang.org/t/add-plots-giving-error/72094)

<div class="topic-metadata">

**Author:** [@majid](https://discourse.julialang.org/u/majid)\
**Replies:** 0\
**Last updated:** [November 26, 2021, 5:34am UTC](https://discourse.julialang.org/t/add-plots-giving-error/72094 "2021-11-26T05:34:41Z")

</div>

This post is deleted.

---

## [ProconIO.jl -- Easy IO handler for competitive programming in Julia](https://discourse.julialang.org/t/proconio-jl-easy-io-handler-for-competitive-programming-in-julia/85391)

<div class="topic-metadata">

**Author:** [@lucifer1004](https://discourse.julialang.org/u/lucifer1004)\
**Replies:** 2\
**Last updated:** [August 8, 2022, 1:24am UTC](https://discourse.julialang.org/t/proconio-jl-easy-io-handler-for-competitive-programming-in-julia/85391 "2022-08-08T01:24:45Z")

</div>

Inspired by proconio-rs, I wrote ProconIO.jl to handle inputs for competitive programming contests. The usage is similar to proconio-rs. You need to specify the variable name and its structure. @input a = Int Multiple…

---

## [Makie, JSServe and Observables: Can I wrap whole figures in Observables?](https://discourse.julialang.org/t/makie-jsserve-and-observables-can-i-wrap-whole-figures-in-observables/82670)

<div class="topic-metadata">

**Author:** [@marcpabst](https://discourse.julialang.org/u/marcpabst)\
**Replies:** 1\
**Last updated:** [August 8, 2022, 12:38am UTC](https://discourse.julialang.org/t/makie-jsserve-and-observables-can-i-wrap-whole-figures-in-observables/82670 "2022-08-08T00:38:18Z")

</div>

Hi there! Mostly a question for @sdanisch I guess, but maybe others know as well… I’m creating interactive plots that work offline using WGLMakie and JSServe. For this, I have a custom function that takes a function wit…

---

## [Can DataFrames be distinguished by type?](https://discourse.julialang.org/t/can-dataframes-be-distinguished-by-type/85442)

<div class="topic-metadata">

**Author:** [@Soldalma](https://discourse.julialang.org/u/Soldalma)\
**Replies:** 1\
**Last updated:** [August 7, 2022, 11:31pm UTC](https://discourse.julialang.org/t/can-dataframes-be-distinguished-by-type/85442 "2022-08-07T23:31:46Z")

</div>

I would like to have a function call fail or not depending on the type of a DataFrame. I cannot distinguish the DataFrames by column types or size. For example, I would have two identical functions except for the argume…

---

## [A vector with custom indices](https://discourse.julialang.org/t/a-vector-with-custom-indices/85373)

<div class="topic-metadata">

**Author:** [@moataz-sabry](https://discourse.julialang.org/u/moataz-sabry)\
**Replies:** 15\
**Last updated:** [August 7, 2022, 11:18pm UTC](https://discourse.julialang.org/t/a-vector-with-custom-indices/85373 "2022-08-07T23:18:18Z")

</div>

is it possible to have a vector with custom predefined non-uniform indexing. Like the following made-up example, I’ve a vector with the values 1, 2, 3 of the indices 29, 360, 400. x = \[1, 2, 3\] for (i, v) in enumerate(…

---

## [Parameter estimation of an ODE in Julia is slower than in R](https://discourse.julialang.org/t/parameter-estimation-of-an-ode-in-julia-is-slower-than-in-r/85114)

<div class="topic-metadata">

**Author:** [@laurar1891](https://discourse.julialang.org/u/laurar1891)\
**Replies:** 25\
**Last updated:** [August 7, 2022, 11:15pm UTC](https://discourse.julialang.org/t/parameter-estimation-of-an-ode-in-julia-is-slower-than-in-r/85114 "2022-08-07T23:15:04Z")

</div>

I’ve been trying to estimate parameters (using max likelihood) of an ODE using the DifferentialEquations and Optim packages in Julia aiming to get a faster convergence compared to R. Problem is that I still can do it fas…

---

## [@enum multiplication](https://discourse.julialang.org/t/enum-multiplication/85213)

<div class="topic-metadata">

**Author:** [@Lincoln\_Hannah](https://discourse.julialang.org/u/Lincoln_Hannah)\
**Replies:** 12\
**Last updated:** [August 7, 2022, 11:04pm UTC](https://discourse.julialang.org/t/enum-multiplication/85213 "2022-08-07T23:04:36Z")

</div>

Is this the best way to do this? @enum BuySell (Buy=1; Sell=-1) import Base.\* \*(x::BuySell, y::Any ) = Int(x) \* y \*(y::Any, x::BuySell) = y \* Int(x) Sell \* 10 # = -10 So I can put \* Buy o…

---

## [Faster matrix product with a specifically structured matrix](https://discourse.julialang.org/t/faster-matrix-product-with-a-specifically-structured-matrix/67355)

<div class="topic-metadata">

**Author:** [@lrnv](https://discourse.julialang.org/u/lrnv)\
**Replies:** 26\
**Last updated:** [August 7, 2022, 8:47pm UTC](https://discourse.julialang.org/t/faster-matrix-product-with-a-specifically-structured-matrix/67355 "2022-08-07T20:47:56Z")

</div>

Hi, I have a sparse matrix P that turns out to have only equal values (or zeros) on each line: julia\> all(\[sum(unique(P\[i,:\]).!=0)\<=1 for i in 1:size(P,1)\]) true julia\> Where I used \<=1 since some lines are complete…

---

## [Can't compile DifferentialEquations on crostini](https://discourse.julialang.org/t/cant-compile-differentialequations-on-crostini/85418)

<div class="topic-metadata">

**Author:** [@MrPat](https://discourse.julialang.org/u/MrPat)\
**Replies:** 2\
**Last updated:** [August 7, 2022, 10:31pm UTC](https://discourse.julialang.org/t/cant-compile-differentialequations-on-crostini/85418 "2022-08-07T22:31:42Z")

</div>

I’m using DifferentialEquations on a pixelbook and I’m getting the following issue: \[ Info: Precompiling DifferentialEquations \[0c46a032-eb83-5123-abaf-570d42b7fbaa\] ERROR: LoadError: LoadError: syntax: invalid assignm…

---

## [Is there any rule to arrange the order of definitions of variables, functions, types, macros in a module?](https://discourse.julialang.org/t/is-there-any-rule-to-arrange-the-order-of-definitions-of-variables-functions-types-macros-in-a-module/85421)

<div class="topic-metadata">

**Author:** [@lionisxn](https://discourse.julialang.org/u/lionisxn)\
**Replies:** 6\
**Last updated:** [August 7, 2022, 10:21pm UTC](https://discourse.julialang.org/t/is-there-any-rule-to-arrange-the-order-of-definitions-of-variables-functions-types-macros-in-a-module/85421 "2022-08-07T22:21:03Z")

</div>

I just found that a type or macro should be declared before being called, but a function is not. Is it to say that functions can be placed in an arbitrary order confined by the only requirment that they must be placed a…

---

## [Sysimage plot in Juno is still slow?](https://discourse.julialang.org/t/sysimage-plot-in-juno-is-still-slow/46051)

<div class="topic-metadata">

**Author:** [@Ahmed\_Salih](https://discourse.julialang.org/u/Ahmed_Salih)\
**Replies:** 0\
**Last updated:** [September 4, 2020, 11:28am UTC](https://discourse.julialang.org/t/sysimage-plot-in-juno-is-still-slow/46051 "2020-09-04T11:28:24Z")

</div>

Hello! I followed this guide to make a sysimage https://julialang.github.io/PackageCompiler.jl/dev/examples/plots/ I succeeded in doing so, but the result I see is: julia\> @time using Plots 0.000901 seconds (445 al…

---

## [Is there a command to tell me if I am the default sysimage or a custom one?](https://discourse.julialang.org/t/is-there-a-command-to-tell-me-if-i-am-the-default-sysimage-or-a-custom-one/63673)

<div class="topic-metadata">

**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 0\
**Last updated:** [June 28, 2021, 5:02am UTC](https://discourse.julialang.org/t/is-there-a-command-to-tell-me-if-i-am-the-default-sysimage-or-a-custom-one/63673 "2021-06-28T05:02:32Z")

</div>

I am using VSCode, I turn on the feature about using a custom sysimage. But often, I am not sure if I am using the default sysimage or a custom one. How can I tell? Is there a command I can type? E.g. one that shows me …

---

## [PackageCompiler: Do optimisation flags influence the produced sysimages?](https://discourse.julialang.org/t/packagecompiler-do-optimisation-flags-influence-the-produced-sysimages/47338)

<div class="topic-metadata">

**Author:** [@SteffenPL](https://discourse.julialang.org/u/SteffenPL)\
**Replies:** 0\
**Last updated:** [September 26, 2020, 9:07pm UTC](https://discourse.julialang.org/t/packagecompiler-do-optimisation-flags-influence-the-produced-sysimages/47338 "2020-09-26T21:07:34Z")

</div>

Is there a difference between julia -O3 -e "import PackageCompiler; PackageCompiler.create\_sysimage(...)" vs julia -e "import PackageCompiler; PackageCompiler.create\_sysimage(...)"? Are the produced sysimages the sa…

---

## [Is there a way to configure Custom sysimage per workspace or project in VSCode?](https://discourse.julialang.org/t/is-there-a-way-to-configure-custom-sysimage-per-workspace-or-project-in-vscode/61840)

<div class="topic-metadata">

**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 0\
**Last updated:** [May 26, 2021, 6:32am UTC](https://discourse.julialang.org/t/is-there-a-way-to-configure-custom-sysimage-per-workspace-or-project-in-vscode/61840 "2021-05-26T06:32:02Z")

</div>

I see the above option mentions the use of a Custom Sysimage, but it’s not which custom sysimage it is using. Using the workspace settings in VScode there is no option for customer sysimage. So I assume it’s not poss…

---

## [Pluto Sysimage](https://discourse.julialang.org/t/pluto-sysimage/75106)

<div class="topic-metadata">

**Author:** [@Timothy](https://discourse.julialang.org/u/Timothy)\
**Replies:** 0\
**Last updated:** [January 24, 2022, 7:04am UTC](https://discourse.julialang.org/t/pluto-sysimage/75106 "2022-01-24T07:04:47Z")

</div>

I am trying to generate a sysimage for my workflow in Pluto. I have specified my notebook file as the precompile execution file in VSCode. However - I can’t generate a sysimage in VSCode. I wonder whether I can not gen…

---

## [EOOR: failed process when using PackageCompiler.create\_sysimage](https://discourse.julialang.org/t/eoor-failed-process-when-using-packagecompiler-create-sysimage/40607)

<div class="topic-metadata">

**Author:** [@yy38819991](https://discourse.julialang.org/u/yy38819991)\
**Replies:** 0\
**Last updated:** [June 2, 2020, 11:26am UTC](https://discourse.julialang.org/t/eoor-failed-process-when-using-packagecompiler-create-sysimage/40607 "2020-06-02T11:26:02Z")

</div>

When I used PackageCompiler.create\_sysimage in Linux OS, an error occurred. Then I tried the same work in another server with Linux OS and the same error appeared. But when I first used the package in my Windows10 comput…

---

## [Error trying to create a custom sysimage in vscode](https://discourse.julialang.org/t/error-trying-to-create-a-custom-sysimage-in-vscode/51281)

<div class="topic-metadata">

**Author:** [@brianguenter](https://discourse.julialang.org/u/brianguenter)\
**Replies:** 0\
**Last updated:** [December 4, 2020, 11:11pm UTC](https://discourse.julialang.org/t/error-trying-to-create-a-custom-sysimage-in-vscode/51281 "2020-12-04T23:11:27Z")

</div>

I’ve been using the custom sysimage creation feature in VSCode for ages. Wonderful, reduces startup time to nearly zero. Just started using Pluto, another fabulous package, and now sysimage compilation doesn’t work, get …

---

## [Download package in julia](https://discourse.julialang.org/t/download-package-in-julia/85445)

<div class="topic-metadata">

**Author:** [@JosieG](https://discourse.julialang.org/u/JosieG)\
**Replies:** 1\
**Last updated:** [August 7, 2022, 7:33pm UTC](https://discourse.julialang.org/t/download-package-in-julia/85445 "2022-08-07T19:33:33Z")

</div>

Hi, I want to download kNN package in julia. The link is KNN · Julia Packages My code is using Pkg Pkg.add("kNN") And I got error kNN (not found in project, manifest or registry) But I can download other packages…

---

## [Print issue single column array](https://discourse.julialang.org/t/print-issue-single-column-array/85250)

<div class="topic-metadata">

**Author:** [@mbraune](https://discourse.julialang.org/u/mbraune)\
**Replies:** 9\
**Last updated:** [August 7, 2022, 7:14pm UTC](https://discourse.julialang.org/t/print-issue-single-column-array/85250 "2022-08-07T19:14:57Z")

</div>

printing single column array in version 1.7.3 shows additional empty element: julia\> A = zeros(Int,3,1) 3×1 Matrix{Int64}: 0 0 0 julia\> print(A) \[0; 0; 0;;\] julia\> I didn’t see such issue in case of multiple col…

---

## [Changing Kernel to different Julia Versions](https://discourse.julialang.org/t/changing-kernel-to-different-julia-versions/85361)

<div class="topic-metadata">

**Author:** [@donkeysaddle](https://discourse.julialang.org/u/donkeysaddle)\
**Replies:** 2\
**Last updated:** [August 7, 2022, 6:01pm UTC](https://discourse.julialang.org/t/changing-kernel-to-different-julia-versions/85361 "2022-08-07T18:01:47Z")

</div>

Hi Gang! I have multiple versions of Julia installed on my Mac. Is there an easy way to switch from one to another while using Jupyter Notebook. I would have thought that they all just show up as options when I go to s…

---

## [LoadError: MethodError: no method matching open(::Nothing, ::String)](https://discourse.julialang.org/t/loaderror-methoderror-no-method-matching-open-nothing-string/85438)

<div class="topic-metadata">

**Author:** [@caozhr](https://discourse.julialang.org/u/caozhr)\
**Replies:** 1\
**Last updated:** [August 7, 2022, 5:43pm UTC](https://discourse.julialang.org/t/loaderror-methoderror-no-method-matching-open-nothing-string/85438 "2022-08-07T17:43:51Z")

</div>

I’m new to Julia. Here, some problems really puzzled me. here is my pipeline, and I think a mistake occurs in line 38: I don’t know how to modify it. The mistake is: ERROR: LoadError: MethodError: no method matching…

[Previous page](https://discourse.julialang.org/latest.md?page=957)

[Next page](https://discourse.julialang.org/latest.md?page=959)