# Latest

**URL:** https://discourse.julialang.org/latest.md?page=939

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

**Page:** 940

---

## [How to round symbolic matrix](https://discourse.julialang.org/t/how-to-round-symbolic-matrix/86507)

<div class="topic-metadata">

**Author:** [@Starpower\_Power](https://discourse.julialang.org/u/Starpower_Power)\
**Replies:** 1\
**Last updated:** [August 29, 2022, 5:44pm UTC](https://discourse.julialang.org/t/how-to-round-symbolic-matrix/86507 "2022-08-29T17:44:13Z")

</div>

i want that output in round form for emp: 1e-17 =0 should be zero. thanks

---

## [Does the singular value degeneracy cause the gradient to be NAN？](https://discourse.julialang.org/t/does-the-singular-value-degeneracy-cause-the-gradient-to-be-nan/86412)

<div class="topic-metadata">

**Author:** [@F-YF](https://discourse.julialang.org/u/F-YF)\
**Replies:** 11\
**Last updated:** [August 29, 2022, 5:37pm UTC](https://discourse.julialang.org/t/does-the-singular-value-degeneracy-cause-the-gradient-to-be-nan/86412 "2022-08-29T17:37:07Z")

</div>

I recently encountered a situation where the result of a computation was of type NAN. I got the following example after a step-by-step debug: using Zygote using OMEinsum using LinearAlgebra function f(T) @ein M\[ b…

---

## [\[JLD2\] How to save an obj on file, replacing that object but not the whole file](https://discourse.julialang.org/t/jld2-how-to-save-an-obj-on-file-replacing-that-object-but-not-the-whole-file/86460)

<div class="topic-metadata">

**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 7\
**Last updated:** [August 29, 2022, 3:42pm UTC](https://discourse.julialang.org/t/jld2-how-to-save-an-obj-on-file-replacing-that-object-but-not-the-whole-file/86460 "2022-08-29T15:42:23Z")

</div>

In JLD2 I would like to save an object to a sort of “library file”, replacing the same object name if it exists, but keeping the other object if they exists. The problem is that even with append JLD2 returns an error if…

---

## [How does one initialize data into a module only once?](https://discourse.julialang.org/t/how-does-one-initialize-data-into-a-module-only-once/85775)

<div class="topic-metadata">

**Author:** [@taotree](https://discourse.julialang.org/u/taotree)\
**Replies:** 12\
**Last updated:** [August 29, 2022, 3:48pm UTC](https://discourse.julialang.org/t/how-does-one-initialize-data-into-a-module-only-once/85775 "2022-08-29T15:48:37Z")

</div>

I need to load and parse a large file and have that data available before a module is used. I thought to put it in \_\_init\_\_ but discovered it was being called multiple times. module A function \_\_init\_\_() println("Load…

---

## [Makie - Use of textbox validator](https://discourse.julialang.org/t/makie-use-of-textbox-validator/86487)

<div class="topic-metadata">

**Author:** [@JB\_15](https://discourse.julialang.org/u/JB_15)\
**Replies:** 4\
**Last updated:** [August 29, 2022, 3:45pm UTC](https://discourse.julialang.org/t/makie-use-of-textbox-validator/86487 "2022-08-29T15:45:27Z")

</div>

Hi I’m trying to use the validator from the Makie Textbox https://makie.juliaplots.org/v0.17.13/examples/blocks/textbox/index.html Could anybody give me an example of how to use the validator? My goal is to verify th…

---

## [Pluto notebook in Julia v1.7.3 vs v1.8.0](https://discourse.julialang.org/t/pluto-notebook-in-julia-v1-7-3-vs-v1-8-0/86465)

<div class="topic-metadata">

**Author:** [@VivMendes](https://discourse.julialang.org/u/VivMendes)\
**Replies:** 4\
**Last updated:** [August 29, 2022, 3:05pm UTC](https://discourse.julialang.org/t/pluto-notebook-in-julia-v1-7-3-vs-v1-8-0/86465 "2022-08-29T15:05:49Z")

</div>

I have a relatively small Pluto notebook. It uses the following packages: using PlotlyBase, HypertextLiteral, PlutoUI using Symbolics:@variables using LinearAlgebra, NLsolve using Dates, PeriodicalDates using DataFrame…

---

## [Force type stability (over block of code)](https://discourse.julialang.org/t/force-type-stability-over-block-of-code/86501)

<div class="topic-metadata">

**Author:** [@Marcell\_Havlik](https://discourse.julialang.org/u/Marcell_Havlik)\
**Replies:** 1\
**Last updated:** [August 29, 2022, 2:41pm UTC](https://discourse.julialang.org/t/force-type-stability-over-block-of-code/86501 "2022-08-29T14:41:43Z")

</div>

Hi Julianners, I saw many attempt on type table block. @code\_warntype to trace them. But in the end I don’t find what is the way to force type stability over a specific block. I want the code to stop or do a warn mes…

---

## [Error using CuIterator with Flux.train!](https://discourse.julialang.org/t/error-using-cuiterator-with-flux-train/86436)

<div class="topic-metadata">

**Author:** [@taotree](https://discourse.julialang.org/u/taotree)\
**Replies:** 2\
**Last updated:** [August 29, 2022, 1:54pm UTC](https://discourse.julialang.org/t/error-using-cuiterator-with-flux-train/86436 "2022-08-29T13:54:59Z")

</div>

I’m trying to use CuIterator and Flux.train!. Attempting to do so gives an error because train! tries to get the length of the CuIterator. So this: iter = CuIterator(batch(i) for i in 1:BATCH\_COUNT) Flux.train!(loss, ps…

---

## [Improving loading time of own package](https://discourse.julialang.org/t/improving-loading-time-of-own-package/85778)

<div class="topic-metadata">

**Author:** [@f.ij](https://discourse.julialang.org/u/f.ij)\
**Replies:** 3\
**Last updated:** [August 29, 2022, 1:36pm UTC](https://discourse.julialang.org/t/improving-loading-time-of-own-package/85778 "2022-08-29T13:36:53Z")

</div>

I’m currently working on creating a package. I’ve got everything working but the time first using it in a project takes quite long, about 17 seconds. Packages that I’m using which are way larger take much less time to lo…

---

## [Slow TagBot. No repo update after 16 hours](https://discourse.julialang.org/t/slow-tagbot-no-repo-update-after-16-hours/80870)

<div class="topic-metadata">

**Author:** [@ctkelley](https://discourse.julialang.org/u/ctkelley)\
**Replies:** 16\
**Last updated:** [August 29, 2022, 1:18pm UTC](https://discourse.julialang.org/t/slow-tagbot-no-repo-update-after-16-hours/80870 "2022-08-29T13:18:43Z")

</div>

I registered a new release of SIAMFANLEquations.jl yesterday. Things seem fine at https://github.com/JuliaRegistries/General/pull/60018 and the new version is in the registry, but my github repo does not show the new…

---

## [Automating download of a fetch api in a website](https://discourse.julialang.org/t/automating-download-of-a-fetch-api-in-a-website/86380)

<div class="topic-metadata">

**Author:** [@tom-plaa](https://discourse.julialang.org/u/tom-plaa)\
**Replies:** 21\
**Last updated:** [August 29, 2022, 1:16pm UTC](https://discourse.julialang.org/t/automating-download-of-a-fetch-api-in-a-website/86380 "2022-08-29T13:16:55Z")

</div>

I’m trying to automate a procedure in a Julia script which is equivalent to going on this page: https://mercado.ren.pt/EN/Electr/MarketInfo/MarketResults/OMIE/Pages/Prices.aspx and downloading a .xls file for the day, …

---

## [Simple communication between tasks](https://discourse.julialang.org/t/simple-communication-between-tasks/86480)

<div class="topic-metadata">

**Author:** [@cstjean](https://discourse.julialang.org/u/cstjean)\
**Replies:** 3\
**Last updated:** [August 29, 2022, 1:14pm UTC](https://discourse.julialang.org/t/simple-communication-between-tasks/86480 "2022-08-29T13:14:30Z")

</div>

I’d like to have two simple tasks, that would symmetrically send values to each other. function task1(other\_task) res1 = send\_to\_other\_task(other\_task, 10) # switch to task2 and blocks until it sends a value @…

---

## [Symbolics.jl and struct](https://discourse.julialang.org/t/symbolics-jl-and-struct/86490)

<div class="topic-metadata">

**Author:** [@qwerty](https://discourse.julialang.org/u/qwerty)\
**Replies:** 4\
**Last updated:** [August 29, 2022, 11:08am UTC](https://discourse.julialang.org/t/symbolics-jl-and-struct/86490 "2022-08-29T11:08:44Z")

</div>

Should I create structs when using Symbolics.jl or is it better not to use structs and always work with purely symbolic expressions? For example, if I wanted to create my functions for calculating the truncated Taylor s…

---

## [Dispatch on symbol name for \`getproperty\`](https://discourse.julialang.org/t/dispatch-on-symbol-name-for-getproperty/86470)

<div class="topic-metadata">

**Author:** [@goerz](https://discourse.julialang.org/u/goerz)\
**Replies:** 8\
**Last updated:** [August 29, 2022, 10:42am UTC](https://discourse.julialang.org/t/dispatch-on-symbol-name-for-getproperty/86470 "2022-08-29T10:42:42Z")

</div>

The documentation for getproperty has this example: function Base.getproperty(obj::MyType, sym::Symbol) if sym === :special return obj.x + 1 else # fallback to getfield return getfield(obj, sym) …

---

## [CUDA memory isn't freed and cannot be backtracked](https://discourse.julialang.org/t/cuda-memory-isnt-freed-and-cannot-be-backtracked/83292)

<div class="topic-metadata">

**Author:** [@Marcell\_Havlik](https://discourse.julialang.org/u/Marcell_Havlik)\
**Replies:** 9\
**Last updated:** [August 29, 2022, 11:03am UTC](https://discourse.julialang.org/t/cuda-memory-isnt-freed-and-cannot-be-backtracked/83292 "2022-08-29T11:03:26Z")

</div>

Hey Julianners, I checked the following topics but couldn’t resolve my issue. https://discourse.julialang.org/t/memory-is-not-freed-with-cuda-and-two-repls/60706 https://cuda.juliagpu.org/stable/usage/memory/ I think…

---

## [Generating functions through an interface (QML)](https://discourse.julialang.org/t/generating-functions-through-an-interface-qml/81362)

<div class="topic-metadata">

**Author:** [@f.ij](https://discourse.julialang.org/u/f.ij)\
**Replies:** 4\
**Last updated:** [May 25, 2022, 2:32pm UTC](https://discourse.julialang.org/t/generating-functions-through-an-interface-qml/81362 "2022-05-25T14:32:56Z")

</div>

Hi all, I ran into the world age problem. What I’m trying to do is to make an interface to a physics simulation (classical spin ising) where the interaction function can be edited by the user. As an example, the interact…

---

## [Explain the syntax to use an instantiated struct name as a method?](https://discourse.julialang.org/t/explain-the-syntax-to-use-an-instantiated-struct-name-as-a-method/86484)

<div class="topic-metadata">

**Author:** [@scoopxyz](https://discourse.julialang.org/u/scoopxyz)\
**Replies:** 3\
**Last updated:** [August 29, 2022, 8:44am UTC](https://discourse.julialang.org/t/explain-the-syntax-to-use-an-instantiated-struct-name-as-a-method/86484 "2022-08-29T08:44:06Z")

</div>

Hello, I came across a interesting way of calling a instantiated struct directly (not initializing) as a method when looking at the Distances.jl module: dist = DistanceType(options) output = dist(x1, x2) I had no idea…

---

## [Fonts in VS Code](https://discourse.julialang.org/t/fonts-in-vs-code/59312)

<div class="topic-metadata">

**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 26\
**Last updated:** [August 29, 2022, 8:48am UTC](https://discourse.julialang.org/t/fonts-in-vs-code/59312 "2022-08-29T08:48:48Z")

</div>

I started using Visual Studio Code in Windows. I noticed that the “hat” (the circumflex mark) is not placed on top of Greek letters, but on the side. It is properly placed for Latin letters. Does anyone know how to fix t…

---

## [Custom backpropagation rule on GPU](https://discourse.julialang.org/t/custom-backpropagation-rule-on-gpu/86459)

<div class="topic-metadata">

**Author:** [@Jakub\_Mitura](https://discourse.julialang.org/u/Jakub_Mitura)\
**Replies:** 2\
**Last updated:** [August 29, 2022, 8:23am UTC](https://discourse.julialang.org/t/custom-backpropagation-rule-on-gpu/86459 "2022-08-29T08:23:37Z")

</div>

Hello I am trying to define the custom Chainrules rrule to be able to use Enzyme on selected functions for backpropagation done generally with Zygote . Kernel and taking derivatives using enzyme works. However, taking ja…

---

## [Documenter warnings](https://discourse.julialang.org/t/documenter-warnings/86464)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 10\
**Last updated:** [August 29, 2022, 8:23am UTC](https://discourse.julialang.org/t/documenter-warnings/86464 "2022-08-29T08:23:59Z")

</div>

When I try to build the documentation of the package GitHub - ufechner7/KiteUtils.jl: Utilities for kite power system simulations using the command: include("docs/make.jl") I get the following warnings: First warning: …

---

## [Simple CuArray conversion, reverse, and transpose taking too long?](https://discourse.julialang.org/t/simple-cuarray-conversion-reverse-and-transpose-taking-too-long/86337)

<div class="topic-metadata">

**Author:** [@aaron\_pung](https://discourse.julialang.org/u/aaron_pung)\
**Replies:** 3\
**Last updated:** [August 29, 2022, 7:57am UTC](https://discourse.julialang.org/t/simple-cuarray-conversion-reverse-and-transpose-taking-too-long/86337 "2022-08-29T07:57:03Z")

</div>

I am ingesting a NetCDF file using the NCDatasets package; the resulting array of type Matrix{Float32} has size (32768,1000). Afterwards, I’m converting the array to a CuArray: \`\`\`using CUDA using NCDatasets CUDA.allow…

---

## [Tree corresponding to expression in Symbolics](https://discourse.julialang.org/t/tree-corresponding-to-expression-in-symbolics/86034)

<div class="topic-metadata">

**Author:** [@qwerty](https://discourse.julialang.org/u/qwerty)\
**Replies:** 3\
**Last updated:** [August 28, 2022, 6:59pm UTC](https://discourse.julialang.org/t/tree-corresponding-to-expression-in-symbolics/86034 "2022-08-28T18:59:57Z")

</div>

In a video on YB I saw that you can get the tree corresponding to the expression with unwrap. tree\_expr = unwrap(sin(cos(x))) How can i access the elements of the tree? Also I saw that it can be displayed with: show…

---

## [LinearSolve and SparseArrays: reuse factorization for multiple right-hand side vectors?](https://discourse.julialang.org/t/linearsolve-and-sparsearrays-reuse-factorization-for-multiple-right-hand-side-vectors/85003)

<div class="topic-metadata">

**Author:** [@afas](https://discourse.julialang.org/u/afas)\
**Replies:** 2\
**Last updated:** [August 29, 2022, 1:15am UTC](https://discourse.julialang.org/t/linearsolve-and-sparsearrays-reuse-factorization-for-multiple-right-hand-side-vectors/85003 "2022-08-29T01:15:51Z")

</div>

Hi everyone, I am implementing several Finite Element procedures in Julia and I am trying to switch all the implementation to use LinearSolve. I would like to know if it is possible to reuse a symbolic factorization of …

---

## [BigFloat converted to string returns different number?](https://discourse.julialang.org/t/bigfloat-converted-to-string-returns-different-number/86473)

<div class="topic-metadata">

**Author:** [@HelloThere](https://discourse.julialang.org/u/HelloThere)\
**Replies:** 8\
**Last updated:** [August 28, 2022, 11:20pm UTC](https://discourse.julialang.org/t/bigfloat-converted-to-string-returns-different-number/86473 "2022-08-28T23:20:47Z")

</div>

Hi, I am new to Julia and in the documentation I came across this: julia\> big"1.23456789012345678901" 1.234567890123456789010000000000000000000000000000000000000000000000000000000004 At first I thought that this is so…

---

## [How to multiply matrices with different structure?](https://discourse.julialang.org/t/how-to-multiply-matrices-with-different-structure/86428)

<div class="topic-metadata">

**Author:** [@ivzktch99](https://discourse.julialang.org/u/ivzktch99)\
**Replies:** 2\
**Last updated:** [August 28, 2022, 9:42pm UTC](https://discourse.julialang.org/t/how-to-multiply-matrices-with-different-structure/86428 "2022-08-28T21:42:10Z")

</div>

I am defining a variable X as a lower trianglar matrix (to reduce the number of variables). How can I multiply it with another dense matrix Y? The following gives me an error using JuMP using LinearAlgebra model = Mode…

---

## [Julia 1.8.0 via conda-forge is now available](https://discourse.julialang.org/t/julia-1-8-0-via-conda-forge-is-now-available/86472)

<div class="topic-metadata">

**Author:** [@mkitti](https://discourse.julialang.org/u/mkitti)\
**Replies:** 0\
**Last updated:** [August 28, 2022, 9:15pm UTC](https://discourse.julialang.org/t/julia-1-8-0-via-conda-forge-is-now-available/86472 "2022-08-28T21:15:13Z")

</div>

Julia 1.8.0 is now available via conda-forge Linux and Mac OS X running on Intel x86\_64 processors. https://anaconda.org/conda-forge/julia Please direct any issues with that build to the julia-feedstock repository with…

---

## [Suggestions for the design of Survey.jl?](https://discourse.julialang.org/t/suggestions-for-the-design-of-survey-jl/86381)

<div class="topic-metadata">

**Author:** [@iuliadmtru](https://discourse.julialang.org/u/iuliadmtru)\
**Replies:** 3\
**Last updated:** [August 28, 2022, 8:18pm UTC](https://discourse.julialang.org/t/suggestions-for-the-design-of-survey-jl/86381 "2022-08-28T20:18:05Z")

</div>

Hello, We are building Survey.jl, a package for statistical estimates from surveys. The inspiration for the package comes from the corresponding R survey package created by Thomas Lumley. We started out imitating the R…

---

## [Reading VTK files into Julia?](https://discourse.julialang.org/t/reading-vtk-files-into-julia/86420)

<div class="topic-metadata">

**Author:** [@Ahmed\_Salih](https://discourse.julialang.org/u/Ahmed_Salih)\
**Replies:** 8\
**Last updated:** [August 28, 2022, 5:19pm UTC](https://discourse.julialang.org/t/reading-vtk-files-into-julia/86420 "2022-08-28T17:19:33Z")

</div>

Hello! Is there any Julia library which wraps the VTK library in such a way that both legacy and new vtk file formats can be read? The top search item is “ReadVTK.jl”, which supposedly can read the new XML vtk file for…

---

## [Can't override method](https://discourse.julialang.org/t/cant-override-method/86419)

<div class="topic-metadata">

**Author:** [@jar1](https://discourse.julialang.org/u/jar1)\
**Replies:** 9\
**Last updated:** [August 28, 2022, 3:11pm UTC](https://discourse.julialang.org/t/cant-override-method/86419 "2022-08-28T15:11:16Z")

</div>

I tried to pirate this method so it doesn’t throw but it is ignored and throws an error. What is wrong? Julia 1.7.1, PrettyTables master \[08abe8d2\] PrettyTables v1.3.1 \`https://github.com/ronisbr/PrettyTables.jl.git#ma…

---

## [What is the best way to avoid world age problem in this case?](https://discourse.julialang.org/t/what-is-the-best-way-to-avoid-world-age-problem-in-this-case/85621)

<div class="topic-metadata">

**Author:** [@Ali\_Vahdati](https://discourse.julialang.org/u/Ali_Vahdati)\
**Replies:** 12\
**Last updated:** [August 28, 2022, 2:01pm UTC](https://discourse.julialang.org/t/what-is-the-best-way-to-avoid-world-age-problem-in-this-case/85621 "2022-08-28T14:01:45Z")

</div>

I am writing a package that uses a YML file as the user interface. Some parameters in the YML file are numbers which are easy to handle. A few parameters need to be functions. I ask the user to put those functions in som…

[Previous page](https://discourse.julialang.org/latest.md?page=938)

[Next page](https://discourse.julialang.org/latest.md?page=940)