# Latest

**URL:** https://discourse.julialang.org/latest.md?page=837

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

**Page:** 838

---

## [How to "copy-past" quote expression in a function?](https://discourse.julialang.org/t/how-to-copy-past-quote-expression-in-a-function/91480)

<div class="topic-metadata">

**Author:** [@Ludovic\_Dumoulin](https://discourse.julialang.org/u/Ludovic_Dumoulin)\
**Replies:** 5\
**Last updated:** [December 14, 2022, 6:51pm UTC](https://discourse.julialang.org/t/how-to-copy-past-quote-expression-in-a-function/91480 "2022-12-14T18:51:11Z")

</div>

Hello, I have some code to copy past in different function / kernel. I saw something about metaprogramming but I have to admit that this is very opaque for me … I would like to know if I can define a quote that contai…

---

## [Flexible design to extend or remove kwarg in functions](https://discourse.julialang.org/t/flexible-design-to-extend-or-remove-kwarg-in-functions/91644)

<div class="topic-metadata">

**Author:** [@Thomas](https://discourse.julialang.org/u/Thomas)\
**Replies:** 1\
**Last updated:** [December 14, 2022, 6:25pm UTC](https://discourse.julialang.org/t/flexible-design-to-extend-or-remove-kwarg-in-functions/91644 "2022-12-14T18:25:29Z")

</div>

Lets say I am defining outer\_func(x; verbose=true) = (y=1;inner\_func(x,y, verbose=verbose) inner\_func(x,y; verbose=false) = (z=x+y;verbose && println(z);z^2) Now I would like to add two kwargs, manually like this oute…

---

## [MethodOfLines.jl now supports Integral Equations and PIDEs](https://discourse.julialang.org/t/methodoflines-jl-now-supports-integral-equations-and-pides/91645)

<div class="topic-metadata">

**Author:** [@xtalax](https://discourse.julialang.org/u/xtalax)\
**Replies:** 0\
**Last updated:** [December 14, 2022, 4:24pm UTC](https://discourse.julialang.org/t/methodoflines-jl-now-supports-integral-equations-and-pides/91645 "2022-12-14T16:24:06Z")

</div>

I’m developing MethodOfLines.jl, an automatic PDE discretizer built on top of Symbolics.jl and ModelingToolkit.jl, and I’m happy to announce that we now support integrals! Currently allowed limits are (xmin…x) (for any …

---

## [DenseAxisArray not working as expected with single dimensional](https://discourse.julialang.org/t/denseaxisarray-not-working-as-expected-with-single-dimensional/91646)

<div class="topic-metadata">

**Author:** [@Mitch\_Phillipson](https://discourse.julialang.org/u/Mitch_Phillipson)\
**Replies:** 2\
**Last updated:** [December 14, 2022, 6:04pm UTC](https://discourse.julialang.org/t/denseaxisarray-not-working-as-expected-with-single-dimensional/91646 "2022-12-14T18:04:13Z")

</div>

I’m trying to set some values on slices of a DenseAxisArray and am getting an error when setting on a single dimensional DenseAxisArray. The following code works exactly as expected: using JuMP.Containers D = DenseAxi…

---

## [Does MethodOfLines replace DiffEqOperators?](https://discourse.julialang.org/t/does-methodoflines-replace-diffeqoperators/91648)

<div class="topic-metadata">

**Author:** [@tictaccat](https://discourse.julialang.org/u/tictaccat)\
**Replies:** 4\
**Last updated:** [December 14, 2022, 5:58pm UTC](https://discourse.julialang.org/t/does-methodoflines-replace-diffeqoperators/91648 "2022-12-14T17:58:33Z")

</div>

My understanding is that DiffEqOperators is being replaced by the combination of SciMLOperators and MethodOfLines. My use case is exactly what DiffEqOperators served: all I want to do is define a matrix-free derivative o…

---

## [A fast reference implementation of a pretty projective geometric algebra](https://discourse.julialang.org/t/a-fast-reference-implementation-of-a-pretty-projective-geometric-algebra/91451)

<div class="topic-metadata">

**Author:** [@g2g](https://discourse.julialang.org/u/g2g)\
**Replies:** 18\
**Last updated:** [December 14, 2022, 5:52pm UTC](https://discourse.julialang.org/t/a-fast-reference-implementation-of-a-pretty-projective-geometric-algebra/91451 "2022-12-14T17:52:25Z")

</div>

As shown at the end of this post, I recently ported pga3d.cpp (the bivector.net C++ reference implementation of projective geometric algebra) to Julia because bivector.net does not currently offer a Julia reference imple…

---

## [Problems with LsqFit on an ODE-based model](https://discourse.julialang.org/t/problems-with-lsqfit-on-an-ode-based-model/91642)

<div class="topic-metadata">

**Author:** [@Eben60](https://discourse.julialang.org/u/Eben60)\
**Replies:** 2\
**Last updated:** [December 14, 2022, 5:48pm UTC](https://discourse.julialang.org/t/problems-with-lsqfit-on-an-ode-based-model/91642 "2022-12-14T17:48:06Z")

</div>

I have a 1D experimental dataset and an ODE-based model. The model is able to describe experimental data reasonably well by manual fitting of the parameter: The next step now is using LsqFit, at first trying to fit ju…

---

## [Problem solved with ChatGPT](https://discourse.julialang.org/t/problem-solved-with-chatgpt/91529)

<div class="topic-metadata">

**Author:** [@Marcell\_Havlik](https://discourse.julialang.org/u/Marcell_Havlik)\
**Replies:** 20\
**Last updated:** [December 14, 2022, 5:44pm UTC](https://discourse.julialang.org/t/problem-solved-with-chatgpt/91529 "2022-12-14T17:44:24Z")

</div>

Hey Julianners, just wanted to share I didn’t ask a question here as ChatGPT answered it instead of the masters. I just wanted to share how freaking incredible this is. As Google like the texts are will copy the te…

---

## [Multiple tasks on GPU resulting in CUSOLVERError for large number of tasks](https://discourse.julialang.org/t/multiple-tasks-on-gpu-resulting-in-cusolvererror-for-large-number-of-tasks/91492)

<div class="topic-metadata">

**Author:** [@Eveee](https://discourse.julialang.org/u/Eveee)\
**Replies:** 4\
**Last updated:** [December 14, 2022, 5:40pm UTC](https://discourse.julialang.org/t/multiple-tasks-on-gpu-resulting-in-cusolvererror-for-large-number-of-tasks/91492 "2022-12-14T17:40:12Z")

</div>

Hi all, I am learning CUDA.jl and trying to launch a bunch of tasks in parallel on the GPU: using LinearAlgebra, Random, CUDA function do\_svd!(c,a::Any) c .= svdvals!(a); end function compute\_gpu(outputs,inputs) …

---

## [Comparing Folds/FLoop Executors](https://discourse.julialang.org/t/comparing-folds-floop-executors/91649)

<div class="topic-metadata">

**Author:** [@markowkes](https://discourse.julialang.org/u/markowkes)\
**Replies:** 0\
**Last updated:** [December 14, 2022, 5:16pm UTC](https://discourse.julialang.org/t/comparing-folds-floop-executors/91649 "2022-12-14T17:16:53Z")

</div>

I wrote the following code to test the various executors profited by Floops.jl and FoldsThreads.jl to distribute work between multiple threads. The code creates work (of various sizes) and distributes this work amongst …

---

## [Offline installation of Julia packages](https://discourse.julialang.org/t/offline-installation-of-julia-packages/20083)

<div class="topic-metadata">

**Author:** [@gdestouet](https://discourse.julialang.org/u/gdestouet)\
**Replies:** 23\
**Last updated:** [December 14, 2022, 3:52pm UTC](https://discourse.julialang.org/t/offline-installation-of-julia-packages/20083 "2022-12-14T15:52:46Z")

</div>

Hello, I need to install a bunch of packages on an offline computer ( it must be disconnected ). I didn’t found any guide that provide a clean way for installing packages offline and maybe someone could help me with th…

---

## [Propensity Score Matching](https://discourse.julialang.org/t/propensity-score-matching/54348)

<div class="topic-metadata">

**Author:** [@Yifan\_Liu](https://discourse.julialang.org/u/Yifan_Liu)\
**Replies:** 6\
**Last updated:** [December 14, 2022, 3:37pm UTC](https://discourse.julialang.org/t/propensity-score-matching/54348 "2022-12-14T15:37:54Z")

</div>

Are there any Julia packages for propensity score matching? I find the R package MatchIt too slow to use. MatchIt: Getting Started

---

## [How to save images from internet to file](https://discourse.julialang.org/t/how-to-save-images-from-internet-to-file/91639)

<div class="topic-metadata">

**Author:** [@edas](https://discourse.julialang.org/u/edas)\
**Replies:** 3\
**Last updated:** [December 14, 2022, 12:55pm UTC](https://discourse.julialang.org/t/how-to-save-images-from-internet-to-file/91639 "2022-12-14T12:55:47Z")

</div>

Hi, I want to save image from internet to file. I cannot find image related information. Below is my example to get page and extract image block. Example site is my own site, using free theme. using HTTP, Gumbo, Casc…

---

## [Duplicating integrator with KLUFactorization(; reuse\_symbolic = true)](https://discourse.julialang.org/t/duplicating-integrator-with-klufactorization-reuse-symbolic-true/91635)

<div class="topic-metadata">

**Author:** [@DanielVandH](https://discourse.julialang.org/u/DanielVandH)\
**Replies:** 4\
**Last updated:** [December 14, 2022, 12:38pm UTC](https://discourse.julialang.org/t/duplicating-integrator-with-klufactorization-reuse-symbolic-true/91635 "2022-12-14T12:38:11Z")

</div>

I have a problem that uses multithreading and I’ve set it up to copy some integrators defining a differential equation problem. I’m running into issues with KLUFactorization(), namely my method fails when KLUFactorizatio…

---

## [Fastest way to add arrays](https://discourse.julialang.org/t/fastest-way-to-add-arrays/91593)

<div class="topic-metadata">

**Author:** [@Marcell\_Havlik](https://discourse.julialang.org/u/Marcell_Havlik)\
**Replies:** 12\
**Last updated:** [December 14, 2022, 11:37am UTC](https://discourse.julialang.org/t/fastest-way-to-add-arrays/91593 "2022-12-14T11:37:54Z")

</div>

Hey Julianners, Can you help me on how to create fast array addition? I believe this is the fastest way: using CUDA using BenchmarkTools BenchmarkTools.DEFAULT\_PARAMETERS.seconds = 1.00 add\_cab(c, a, b) = @inbounds …

---

## [Path of this package?](https://discourse.julialang.org/t/path-of-this-package/16401)

<div class="topic-metadata">

**Author:** [@e3c6](https://discourse.julialang.org/u/e3c6)\
**Replies:** 28\
**Last updated:** [December 14, 2022, 11:11am UTC](https://discourse.julialang.org/t/path-of-this-package/16401 "2022-12-14T11:11:04Z")

</div>

Suppose I am developing a package MyPkg. How can I get the path to MyPkg.jl? I used Pkg.dir() \* "MyPkg/", but that doesn’t work in Julia 1.0 anymore

---

## [How exactly do optimizers reject infinity loss?](https://discourse.julialang.org/t/how-exactly-do-optimizers-reject-infinity-loss/91597)

<div class="topic-metadata">

**Author:** [@fanny1](https://discourse.julialang.org/u/fanny1)\
**Replies:** 4\
**Last updated:** [December 14, 2022, 10:31am UTC](https://discourse.julialang.org/t/how-exactly-do-optimizers-reject-infinity-loss/91597 "2022-12-14T10:31:54Z")

</div>

Hi, I was reading the documentation and on this page Frequently Asked Questions of DifferentialEquations.jl, in the Stability and Divergence section, it says: if you see these instability warnings during a parameter es…

---

## [Why \`@nospecialize(ex)\` in macros?](https://discourse.julialang.org/t/why-nospecialize-ex-in-macros/91589)

<div class="topic-metadata">

**Author:** [@tfiers](https://discourse.julialang.org/u/tfiers)\
**Replies:** 2\
**Last updated:** [December 14, 2022, 8:28am UTC](https://discourse.julialang.org/t/why-nospecialize-ex-in-macros/91589 "2022-12-14T08:28:04Z")

</div>

Why do Julia experts use @nospecialize(ex) in functions used by macros? E.g. here: Typed globals: macro to define multiple, without manual type annotations - #2 by simeonschaub I’d say the only types the argument could…

---

## [f(x::MyType{T, S}) where (T || S) \<: Foo?](https://discourse.julialang.org/t/f-x-mytype-t-s-where-t-s-foo/91581)

<div class="topic-metadata">

**Author:** [@cjwyett](https://discourse.julialang.org/u/cjwyett)\
**Replies:** 15\
**Last updated:** [December 14, 2022, 5:40am UTC](https://discourse.julialang.org/t/f-x-mytype-t-s-where-t-s-foo/91581 "2022-12-14T05:40:24Z")

</div>

Hi, I have a type where I want a different dispatch if one of the parameters is Foo. abstract type FooBarBaz end struct Foo \<: FooBarBaz end struct Bar \<: FooBarBaz end struct Baz \<: FooBarBaz end struct MyType{T\<:F…

---

## [FEM Basis and Integration package similar to fenics-basix?](https://discourse.julialang.org/t/fem-basis-and-integration-package-similar-to-fenics-basix/91629)

<div class="topic-metadata">

**Author:** [@lucasbanting](https://discourse.julialang.org/u/lucasbanting)\
**Replies:** 6\
**Last updated:** [December 14, 2022, 4:03am UTC](https://discourse.julialang.org/t/fem-basis-and-integration-package-similar-to-fenics-basix/91629 "2022-12-14T04:03:40Z")

</div>

I’m looking for a package to define quadrature points on simplex elements, as well as a variety of basis function types (specifically high order Lagrange polynomials and high order nedelec elements), similar to: GitHub -…

---

## [Web-scraping with Julia](https://discourse.julialang.org/t/web-scraping-with-julia/91596)

<div class="topic-metadata">

**Author:** [@Andrej\_Ranisavljevic](https://discourse.julialang.org/u/Andrej_Ranisavljevic)\
**Replies:** 1\
**Last updated:** [December 14, 2022, 3:28am UTC](https://discourse.julialang.org/t/web-scraping-with-julia/91596 "2022-12-14T03:28:03Z")

</div>

Is there any way to scrape data from login required websites with Julia? I’ve used Gumbo and Cascadia so far for non-login websites but i can’t seem to find any solution for websites that require login.

---

## [In numerical computation, how could increasing the number of bits of precision decrease accuracy?](https://discourse.julialang.org/t/in-numerical-computation-how-could-increasing-the-number-of-bits-of-precision-decrease-accuracy/91600)

<div class="topic-metadata">

**Author:** [@nsajko](https://discourse.julialang.org/u/nsajko)\
**Replies:** 13\
**Last updated:** [December 14, 2022, 1:20am UTC](https://discourse.julialang.org/t/in-numerical-computation-how-could-increasing-the-number-of-bits-of-precision-decrease-accuracy/91600 "2022-12-14T01:20:32Z")

</div>

In this PolynomialRoots.jl Github Issue, accuracy of the result is relatively OK when the MPFR/BigFloat precision is at around (just!) twenty bits, but goes sour suddenly when increasing the number of bits and stays that…

---

## [Non-Zygote autodiff through a FFT-based poisson solver?](https://discourse.julialang.org/t/non-zygote-autodiff-through-a-fft-based-poisson-solver/88191)

<div class="topic-metadata">

**Author:** [@trakjohnson](https://discourse.julialang.org/u/trakjohnson)\
**Replies:** 3\
**Last updated:** [December 14, 2022, 12:16am UTC](https://discourse.julialang.org/t/non-zygote-autodiff-through-a-fft-based-poisson-solver/88191 "2022-12-14T00:16:06Z")

</div>

Hi all, I’m attempting to figure out how to automatically differentiate through code that uses FFTs and IFFTs. I know there are a few topics on this (I’ve referenced some) and I have tried to do my best to get the most …

---

## [Plotting sets using natural mathematical set expressions](https://discourse.julialang.org/t/plotting-sets-using-natural-mathematical-set-expressions/91582)

<div class="topic-metadata">

**Author:** [@tapyu](https://discourse.julialang.org/u/tapyu)\
**Replies:** 10\
**Last updated:** [December 13, 2022, 11:10pm UTC](https://discourse.julialang.org/t/plotting-sets-using-natural-mathematical-set-expressions/91582 "2022-12-13T23:10:10Z")

</div>

In convex optimization, it is quite common to come across a n-dimensional set formally written like that, for example, C = \\left\\{ (x\_1, x\_2, \\cdots, x\_n, t) \\in \\mathbb{R}^{n+1} \\mid \\mathbf{x} \\in \\mathbb{R}^{n}, \\lV…

---

## [How to express an objective with L1-norm in JuMP.jl?](https://discourse.julialang.org/t/how-to-express-an-objective-with-l1-norm-in-jump-jl/91387)

<div class="topic-metadata">

**Author:** [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Replies:** 7\
**Last updated:** [December 13, 2022, 10:42pm UTC](https://discourse.julialang.org/t/how-to-express-an-objective-with-l1-norm-in-jump-jl/91387 "2022-12-13T22:42:06Z")

</div>

I learned about the NormOneCone, which can be used to add L1 constraints to a model. How to minimize the L1 norm of a vector of residuals? Tried @objective(model, Min, sum(abs.(x))) but it is not recognized by JuMP.jl.

---

## [Problem with array of structs](https://discourse.julialang.org/t/problem-with-array-of-structs/91614)

<div class="topic-metadata">

**Author:** [@teob](https://discourse.julialang.org/u/teob)\
**Replies:** 2\
**Last updated:** [December 13, 2022, 6:49pm UTC](https://discourse.julialang.org/t/problem-with-array-of-structs/91614 "2022-12-13T18:49:34Z")

</div>

Hello everyone, I have the following problem: Base.@kwdef struct s a = \[0.0,0.0,0.0\] end vec = fill(s(), 3) for (indx,v) in enumerate(vec) v.a\[1\] = indx end vec retruns: 3-element Vector{s}: s(\[3.0, 0.0, 0…

---

## [Using @test\_throws for any error/excpeption](https://discourse.julialang.org/t/using-test-throws-for-any-error-excpeption/91609)

<div class="topic-metadata">

**Author:** [@HashBrown](https://discourse.julialang.org/u/HashBrown)\
**Replies:** 1\
**Last updated:** [December 13, 2022, 6:02pm UTC](https://discourse.julialang.org/t/using-test-throws-for-any-error-excpeption/91609 "2022-12-13T18:02:41Z")

</div>

I want to test that certain uses of my code throws an error, however I am not concerned with exactly what type of error. Is there a way to use @test\_throws without specifying the exact type of error?

---

## [Parallel strategies recommendation](https://discourse.julialang.org/t/parallel-strategies-recommendation/91580)

<div class="topic-metadata">

**Author:** [@Carol](https://discourse.julialang.org/u/Carol)\
**Replies:** 2\
**Last updated:** [December 13, 2022, 5:28pm UTC](https://discourse.julialang.org/t/parallel-strategies-recommendation/91580 "2022-12-13T17:28:41Z")

</div>

Hi, I want to discuss a better parallel strategy for my current code. I have a data matrix with 500,000 columns: step1: each column will be used (independently) in function 1, where the column will be updated at the …

---

## [Recommended way of disabling precompilation for a package I'm dev'ing](https://discourse.julialang.org/t/recommended-way-of-disabling-precompilation-for-a-package-im-deving/91539)

<div class="topic-metadata">

**Author:** [@tictaccat](https://discourse.julialang.org/u/tictaccat)\
**Replies:** 3\
**Last updated:** [December 13, 2022, 4:55pm UTC](https://discourse.julialang.org/t/recommended-way-of-disabling-precompilation-for-a-package-im-deving/91539 "2022-12-13T16:55:41Z")

</div>

I’m currently in the situation where I’m in dev mode for a package X and actively making changes to its source. But this makes a package Y which depends on X have very long precompilation times every time I have to quit …

---

## [Error in launching process on LSF Cluster, after updating Julia version](https://discourse.julialang.org/t/error-in-launching-process-on-lsf-cluster-after-updating-julia-version/91601)

<div class="topic-metadata">

**Author:** [@marcobonici](https://discourse.julialang.org/u/marcobonici)\
**Replies:** 0\
**Last updated:** [December 13, 2022, 1:13pm UTC](https://discourse.julialang.org/t/error-in-launching-process-on-lsf-cluster-after-updating-julia-version/91601 "2022-12-13T13:13:20Z")

</div>

Hi, I have added a new julia version on my university Cluster, moving from 1.7.2 to 1.8.3. I have add ClusterManagers and tried adding some processes, as I have always done. The problem is that I am not being able to a…

[Previous page](https://discourse.julialang.org/latest.md?page=836)

[Next page](https://discourse.julialang.org/latest.md?page=838)