# Latest

**URL:** https://discourse.julialang.org/latest.md?page=977

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

**Page:** 978

---

## [Package or method to determine truth table or is a statement is a Tautology?](https://discourse.julialang.org/t/package-or-method-to-determine-truth-table-or-is-a-statement-is-a-tautology/84415)

<div class="topic-metadata">

**Author:** [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)\
**Replies:** 6\
**Last updated:** [July 19, 2022, 4:39pm UTC](https://discourse.julialang.org/t/package-or-method-to-determine-truth-table-or-is-a-statement-is-a-tautology/84415 "2022-07-19T16:39:20Z")

</div>

Hi all, I was wondering is there anything close to or similar function/method that can be used to determine if a combination of 2 values are tautology (a statement that is always true). It is a basic logic statements i…

---

## [Is it possible to create a virtual environment using CUDA?](https://discourse.julialang.org/t/is-it-possible-to-create-a-virtual-environment-using-cuda/84185)

<div class="topic-metadata">

**Author:** [@Fathya.Salih](https://discourse.julialang.org/u/Fathya.Salih)\
**Replies:** 3\
**Last updated:** [July 19, 2022, 3:25pm UTC](https://discourse.julialang.org/t/is-it-possible-to-create-a-virtual-environment-using-cuda/84185 "2022-07-19T15:25:03Z")

</div>

Hello! I am trying to use julia 1.2.0 on a remote GPU system and I am having trouble creating a virtual environment where I can add the packages I need. These are the packages available in the remote machine: (v1.2) pk…

---

## [Where does this allocation come from and how to avoid it? StaticArrays and structures](https://discourse.julialang.org/t/where-does-this-allocation-come-from-and-how-to-avoid-it-staticarrays-and-structures/84462)

<div class="topic-metadata">

**Author:** [@coloboquito](https://discourse.julialang.org/u/coloboquito)\
**Replies:** 3\
**Last updated:** [July 19, 2022, 2:50pm UTC](https://discourse.julialang.org/t/where-does-this-allocation-come-from-and-how-to-avoid-it-staticarrays-and-structures/84462 "2022-07-19T14:50:13Z")

</div>

Hello! I’m trying to optimize my code and I’m stuck on this. Here is a minimum working example of my problem. f(x :: T, y :: T, z :: T) = SA\[x, y, z\] struct Foo{T \<: Real} x :: T; y :: T; z :: T end f(foo :: Foo…

---

## [Is it possible to make scrollable window in GLMakie](https://discourse.julialang.org/t/is-it-possible-to-make-scrollable-window-in-glmakie/84450)

<div class="topic-metadata">

**Author:** [@Thomberger](https://discourse.julialang.org/u/Thomberger)\
**Replies:** 1\
**Last updated:** [July 19, 2022, 2:25pm UTC](https://discourse.julialang.org/t/is-it-possible-to-make-scrollable-window-in-glmakie/84450 "2022-07-19T14:25:52Z")

</div>

Is it possible to create a window longer than the screen height and make it scrollable, either using sliders, keyboard down arrow, or any other solution ?

---

## [ERROR: MethodError: no method matching expand\_extrema!(::Plots.Axis, ::Vector{Matrix{Float64}})](https://discourse.julialang.org/t/error-methoderror-no-method-matching-expand-extrema-plots-axis-vector-matrix-float64/84459)

<div class="topic-metadata">

**Author:** [@Hupdup](https://discourse.julialang.org/u/Hupdup)\
**Replies:** 2\
**Last updated:** [July 19, 2022, 1:59pm UTC](https://discourse.julialang.org/t/error-methoderror-no-method-matching-expand-extrema-plots-axis-vector-matrix-float64/84459 "2022-07-19T13:59:51Z")

</div>

Hi, I want to plot a confidence interval, but unfourtunaly I am not able to do it. I got the following error message: ERROR: MethodError: no method matching expand\_extrema!(::Plots.Axis, ::Vector{Matrix{Float64}}) The…

---

## [Inverse ICA for denoising](https://discourse.julialang.org/t/inverse-ica-for-denoising/84334)

<div class="topic-metadata">

**Author:** [@nbagg](https://discourse.julialang.org/u/nbagg)\
**Replies:** 2\
**Last updated:** [July 19, 2022, 1:47pm UTC](https://discourse.julialang.org/t/inverse-ica-for-denoising/84334 "2022-07-19T13:47:14Z")

</div>

Hi there, I am trying to use ICA to denoise an EEG signal. I am currently using the MultivariateStats.jl to perform the ICA: W = fit(ICA, data, num\_elec) This returns the mixing matrix as an ICA model. I want the inv…

---

## [Submitted arrays of different types in JuMP Heuristic Callbacks](https://discourse.julialang.org/t/submitted-arrays-of-different-types-in-jump-heuristic-callbacks/83950)

<div class="topic-metadata">

**Author:** [@K5Julien](https://discourse.julialang.org/u/K5Julien)\
**Replies:** 2\
**Last updated:** [July 19, 2022, 1:31pm UTC](https://discourse.julialang.org/t/submitted-arrays-of-different-types-in-jump-heuristic-callbacks/83950 "2022-07-19T13:31:33Z")

</div>

Hi! I am sorry, I can not produce a MWE but I think you can still answer my question. I need to use JuMP heuristic callbacks. However, the documentation only gives an exemple for a single variable. I need to submit a h…

---

## [Order of parameters in outer constructor matters?](https://discourse.julialang.org/t/order-of-parameters-in-outer-constructor-matters/84367)

<div class="topic-metadata">

**Author:** [@ac1643](https://discourse.julialang.org/u/ac1643)\
**Replies:** 3\
**Last updated:** [July 19, 2022, 1:11pm UTC](https://discourse.julialang.org/t/order-of-parameters-in-outer-constructor-matters/84367 "2022-07-19T13:11:04Z")

</div>

I am playing around with parametric types and constructors. First I have a type and constructor as julia\> struct Foo{T, N} val::T end julia\> function Foo{N}() where {N} return Foo{Int, N}(1…

---

## [BLAS performance testing for Julia 1.8](https://discourse.julialang.org/t/blas-performance-testing-for-julia-1-8/69520)

<div class="topic-metadata">

**Author:** [@viralbshah](https://discourse.julialang.org/u/viralbshah)\
**Replies:** 30\
**Last updated:** [July 19, 2022, 7:30am UTC](https://discourse.julialang.org/t/blas-performance-testing-for-julia-1-8/69520 "2022-07-19T07:30:38Z")

</div>

OpenBLAS had two threading related defaults that we used to set until recently, both of which are now relaxed, since openblas has improved on both these fronts: We used to build openblas with 32 max threads (at some po…

---

## [Grouping by Split, apply, combine](https://discourse.julialang.org/t/grouping-by-split-apply-combine/84417)

<div class="topic-metadata">

**Author:** [@Optimization](https://discourse.julialang.org/u/Optimization)\
**Replies:** 9\
**Last updated:** [July 19, 2022, 10:06am UTC](https://discourse.julialang.org/t/grouping-by-split-apply-combine/84417 "2022-07-19T10:06:48Z")

</div>

I have a big set of 4-tuples and would like to group them based on their third position. As an example: using SplitApplyCombine A = \[(1,5,2,5), (,12,5,9,6), (7,5,2,6), (11,5,2,5), (8,5,9,6), (3,5,3,6), (7,5,9,6), (1,5,3…

---

## [Weighted graph using SparseCSC julia](https://discourse.julialang.org/t/weighted-graph-using-sparsecsc-julia/84071)

<div class="topic-metadata">

**Author:** [@ayodyas](https://discourse.julialang.org/u/ayodyas)\
**Replies:** 8\
**Last updated:** [July 19, 2022, 7:31am UTC](https://discourse.julialang.org/t/weighted-graph-using-sparsecsc-julia/84071 "2022-07-19T07:31:43Z")

</div>

I am new to julia and was trying to do weighted graph partition using metis in Julia. I coudnt undertstand how the SparseCSc for graph creation with edge and vertex weight as required for format of the metis (graph parti…

---

## [RGB has a length but no iterate?](https://discourse.julialang.org/t/rgb-has-a-length-but-no-iterate/84446)

<div class="topic-metadata">

**Author:** [@xor0110](https://discourse.julialang.org/u/xor0110)\
**Replies:** 2\
**Last updated:** [July 19, 2022, 9:34am UTC](https://discourse.julialang.org/t/rgb-has-a-length-but-no-iterate/84446 "2022-07-19T09:34:36Z")

</div>

I’m defining a handy function for me to flatten data recursively into matrices and tensors. One way to do it is to descend into the list-of-lists until we see something with length(x)==1, and then we consider that to be …

---

## [Randomly select x% of elements in a array/matrix](https://discourse.julialang.org/t/randomly-select-x-of-elements-in-a-array-matrix/84369)

<div class="topic-metadata">

**Author:** [@vshesh](https://discourse.julialang.org/u/vshesh)\
**Replies:** 11\
**Last updated:** [July 19, 2022, 8:15am UTC](https://discourse.julialang.org/t/randomly-select-x-of-elements-in-a-array-matrix/84369 "2022-07-19T08:15:44Z")

</div>

Let’s say I have a matrix like: m = rand(50,100) And now I want to select, say, 10% of the data in this matrix (a view will work, I don’t need a new array). import Random m\[:, Random.randperm(100)\[1:10\]\] Is there a b…

---

## [Convert string months (January, February, March, etc.) to date format](https://discourse.julialang.org/t/convert-string-months-january-february-march-etc-to-date-format/84444)

<div class="topic-metadata">

**Author:** [@Nash](https://discourse.julialang.org/u/Nash)\
**Replies:** 1\
**Last updated:** [July 19, 2022, 8:18am UTC](https://discourse.julialang.org/t/convert-string-months-january-february-march-etc-to-date-format/84444 "2022-07-19T08:18:21Z")

</div>

I have a database where one of the columns contains the strings for months spelled out in english and the first letter capitalized (January, February, March, etc.). How do I convert the column to a date format?

---

## [Using ImageMagick on Windows](https://discourse.julialang.org/t/using-imagemagick-on-windows/84442)

<div class="topic-metadata">

**Author:** [@wpowell](https://discourse.julialang.org/u/wpowell)\
**Replies:** 0\
**Last updated:** [July 19, 2022, 6:52am UTC](https://discourse.julialang.org/t/using-imagemagick-on-windows/84442 "2022-07-19T06:52:52Z")

</div>

Hi All, I am trying to use ImageMagick’s convert (from pdf to png) - working fine on macOS and Ubuntu but failing on Windows 10. Converting other formats is fine - it seems to be an issue with pdf files only that I thin…

---

## [Machine Learning Property Loans for Fun and Profit with MLJ.jl](https://discourse.julialang.org/t/machine-learning-property-loans-for-fun-and-profit-with-mlj-jl/84414)

<div class="topic-metadata">

**Author:** [@dm13450](https://discourse.julialang.org/u/dm13450)\
**Replies:** 4\
**Last updated:** [July 19, 2022, 6:29am UTC](https://discourse.julialang.org/t/machine-learning-property-loans-for-fun-and-profit-with-mlj-jl/84414 "2022-07-19T06:29:01Z")

</div>

I’ve written a post about using Julia and MLJ on a dataset of property loans. It was my first time really getting to grips with the MLJ framework and I really liked the one-stop interface for the different models. Th…

---

## [How to highlight the area between four lines in julia Plots.jl](https://discourse.julialang.org/t/how-to-highlight-the-area-between-four-lines-in-julia-plots-jl/84433)

<div class="topic-metadata">

**Author:** [@Alex\_ricci](https://discourse.julialang.org/u/Alex_ricci)\
**Replies:** 2\
**Last updated:** [July 19, 2022, 5:41am UTC](https://discourse.julialang.org/t/how-to-highlight-the-area-between-four-lines-in-julia-plots-jl/84433 "2022-07-19T05:41:16Z")

</div>

I want to visualize a simple optimization problem. The problem is: min 3x + 2y s.t. -3x + 3y \<= 5 2x + 3y \>= 9 x, y \>= 0 How it is possible to highlight the feasible region in this problem. In other words, I want …

---

## [How transform the c++ code to julia?](https://discourse.julialang.org/t/how-transform-the-c-code-to-julia/84392)

<div class="topic-metadata">

**Author:** [@zsz00](https://discourse.julialang.org/u/zsz00)\
**Replies:** 12\
**Last updated:** [July 19, 2022, 5:12am UTC](https://discourse.julialang.org/t/how-transform-the-c-code-to-julia/84392 "2022-07-19T05:12:49Z")

</div>

how transform the c++ code to julia ?? How modify the julia code so that it works as the c++ code? ignore the part of visualization (opencv). code in : use ffmpeg to get and draw motion vector. c++ code typedef st…

---

## [How to use all of the cpu cores in IJulia using broadcasting function?](https://discourse.julialang.org/t/how-to-use-all-of-the-cpu-cores-in-ijulia-using-broadcasting-function/84418)

<div class="topic-metadata">

**Author:** [@Phuntsho](https://discourse.julialang.org/u/Phuntsho)\
**Replies:** 4\
**Last updated:** [July 19, 2022, 5:10am UTC](https://discourse.julialang.org/t/how-to-use-all-of-the-cpu-cores-in-ijulia-using-broadcasting-function/84418 "2022-07-19T05:10:55Z")

</div>

I am relatively new to Julia and I have been exploring how to parallel process functions in IJulia. I have created a Jupyter notebook for 128 cores using the directions given here. I can confirm that it has imported all …

---

## [\[ANN\] AstroNbodySim.jl: Unitful and differentiable gravitational N-body simulation code in Julia](https://discourse.julialang.org/t/ann-astronbodysim-jl-unitful-and-differentiable-gravitational-n-body-simulation-code-in-julia/74782)

<div class="topic-metadata">

**Author:** [@islent](https://discourse.julialang.org/u/islent)\
**Replies:** 30\
**Last updated:** [July 19, 2022, 4:22am UTC](https://discourse.julialang.org/t/ann-astronbodysim-jl-unitful-and-differentiable-gravitational-n-body-simulation-code-in-julia/74782 "2022-07-19T04:22:41Z")

</div>

It is a package for scientific gravitational n-body simulations, with following features: Compute with units User-friendly Well documented Readable programming Vectorized array operations Dispatch on types for vario…

---

## [Is there Julia library for AI Image Denoising?](https://discourse.julialang.org/t/is-there-julia-library-for-ai-image-denoising/75688)

<div class="topic-metadata">

**Author:** [@anon28281882](https://discourse.julialang.org/u/anon28281882)\
**Replies:** 12\
**Last updated:** [July 18, 2022, 10:59pm UTC](https://discourse.julialang.org/t/is-there-julia-library-for-ai-image-denoising/75688 "2022-07-18T22:59:44Z")

</div>

Actually, my question is like in the title. I am wondering if there is Julia library that makes Artificial Intelligence Image Denoising possible.

---

## [\[ANN\] PkgJogger.jl: Revise-compatible and boilerplate-free package benchmarking](https://discourse.julialang.org/t/ann-pkgjogger-jl-revise-compatible-and-boilerplate-free-package-benchmarking/84402)

<div class="topic-metadata">

**Author:** [@awadell1](https://discourse.julialang.org/u/awadell1)\
**Replies:** 2\
**Last updated:** [July 18, 2022, 10:43pm UTC](https://discourse.julialang.org/t/ann-pkgjogger-jl-revise-compatible-and-boilerplate-free-package-benchmarking/84402 "2022-07-18T22:43:39Z")

</div>

PkgJogger.jl is a Revise-compatible, boilerplate-free tool for running your package’s benchmarking suite built on top of BenchmarkTools.jl. I’ve been using it for about a year and figured it was time to share it with the…

---

## [Julia JuMP | Continue even when an infeasible solution is found](https://discourse.julialang.org/t/julia-jump-continue-even-when-an-infeasible-solution-is-found/84424)

<div class="topic-metadata">

**Author:** [@hexjulia](https://discourse.julialang.org/u/hexjulia)\
**Replies:** 2\
**Last updated:** [July 18, 2022, 10:32pm UTC](https://discourse.julialang.org/t/julia-jump-continue-even-when-an-infeasible-solution-is-found/84424 "2022-07-18T22:32:31Z")

</div>

Hello! I’m wondering if there’s any way for JuMP (specifically Clp) to continue even when an infeasible solution is found during an SDDP system optimization. Frequently running into problems where a primal solution is …

---

## [Github action stable and dev documentations](https://discourse.julialang.org/t/github-action-stable-and-dev-documentations/84385)

<div class="topic-metadata">

**Author:** [@\_stla](https://discourse.julialang.org/u/_stla)\
**Replies:** 8\
**Last updated:** [July 18, 2022, 9:54pm UTC](https://discourse.julialang.org/t/github-action-stable-and-dev-documentations/84385 "2022-07-18T21:54:51Z")

</div>

Hello, I’d like to register my package JackPolynomials (and others). I have a Github action for the documentation: docs: name: Documentation runs-on: ubuntu-latest steps: - uses: actions/checkout@v2…

---

## [Speeding up mapslices](https://discourse.julialang.org/t/speeding-up-mapslices/61907)

<div class="topic-metadata">

**Author:** [@nandoconde](https://discourse.julialang.org/u/nandoconde)\
**Replies:** 0\
**Last updated:** [May 27, 2021, 9:01am UTC](https://discourse.julialang.org/t/speeding-up-mapslices/61907 "2021-05-27T09:01:28Z")

</div>

Hello! I was trying to perform a matrix inversion in a 3-D array along the third dimension (more info here) and reached two possible solutions. First solution – Manual inversion I am not worrying too much about strange…

---

## [Alternative to Matlab Signal Integrity Toolbox using Julia?](https://discourse.julialang.org/t/alternative-to-matlab-signal-integrity-toolbox-using-julia/84403)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 3\
**Last updated:** [July 18, 2022, 7:20pm UTC](https://discourse.julialang.org/t/alternative-to-matlab-signal-integrity-toolbox-using-julia/84403 "2022-07-18T19:20:31Z")

</div>

Is there a way to do signal integrity analysis with Julia in a similar way to using this Matlab toolbox: Signal Integrity Toolbox - MATLAB ?

---

## [Substring function?](https://discourse.julialang.org/t/substring-function/76675)

<div class="topic-metadata">

**Author:** [@rogerkeays](https://discourse.julialang.org/u/rogerkeays)\
**Replies:** 42\
**Last updated:** [July 18, 2022, 4:41pm UTC](https://discourse.julialang.org/t/substring-function/76675 "2022-07-18T16:41:00Z")

</div>

I found first(str), last(str), and chop(str), but couldn’t find anything for getting a substring where multibyte unicode characters are involved. Something like: substring(str, start, stop) = str\[nextind(str, 0, start):…

---

## [Who understands julia's typeinference in depth?](https://discourse.julialang.org/t/who-understands-julias-typeinference-in-depth/84419)

<div class="topic-metadata">

**Author:** [@schlichtanders](https://discourse.julialang.org/u/schlichtanders)\
**Replies:** 1\
**Last updated:** [July 18, 2022, 7:00pm UTC](https://discourse.julialang.org/t/who-understands-julias-typeinference-in-depth/84419 "2022-07-18T19:00:33Z")

</div>

I already opened an issue for some weird typeinference which blocks me optimizing one of my packages. It would be really great if someone with in-depth julia compiler type-inference knowledge can take a look: https://gi…

---

## [LinearAlgebra: unstable floating point operations?](https://discourse.julialang.org/t/linearalgebra-unstable-floating-point-operations/45581)

<div class="topic-metadata">

**Author:** [@mastrof](https://discourse.julialang.org/u/mastrof)\
**Replies:** 10\
**Last updated:** [July 18, 2022, 6:43pm UTC](https://discourse.julialang.org/t/linearalgebra-unstable-floating-point-operations/45581 "2022-07-18T18:43:30Z")

</div>

Hello, I had some scripts running and at some point I noticed that some unexpected error was thrown: ERROR: LoadError: TaskFailedException: DomainError with 1.0000000000000002: acos(x) not defined for |x| \> 1 Stacktrace…

---

## [Reading output from external program in stdout](https://discourse.julialang.org/t/reading-output-from-external-program-in-stdout/84289)

<div class="topic-metadata">

**Author:** [@Elmo](https://discourse.julialang.org/u/Elmo)\
**Replies:** 7\
**Last updated:** [July 18, 2022, 4:16pm UTC](https://discourse.julialang.org/t/reading-output-from-external-program-in-stdout/84289 "2022-07-18T16:16:31Z")

</div>

I am trying to use Julia to read messages sent to me through xmpp using go-sendxmpp. By following the readme of this package, I can successfully use the terminal to listen to all messages sent to me through: PS C:\\Users…

[Previous page](https://discourse.julialang.org/latest.md?page=976)

[Next page](https://discourse.julialang.org/latest.md?page=978)