# Latest

**URL:** https://discourse.julialang.org/latest.md?page=903

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

**Page:** 904

---

## [Should inv(::Rational) make copies of the numerator and denominator?](https://discourse.julialang.org/t/should-inv-rational-make-copies-of-the-numerator-and-denominator/88314)

<div class="topic-metadata">

**Author:** [@nsajko](https://discourse.julialang.org/u/nsajko)\
**Replies:** 3\
**Last updated:** [October 6, 2022, 11:30am UTC](https://discourse.julialang.org/t/should-inv-rational-make-copies-of-the-numerator-and-denominator/88314 "2022-10-06T11:30:02Z")

</div>

Usually operations on Rational numbers don’t return references to their arguments: julia\> d = Rational{BigInt}(2) 2//1 julia\> d.num === (1\*d).num false julia\> d.num === (0+d).num false I assumed that this holds in ge…

---

## [Rotr90 of a CUDA.CuArray](https://discourse.julialang.org/t/rotr90-of-a-cuda-cuarray/88308)

<div class="topic-metadata">

**Author:** [@leifdenby](https://discourse.julialang.org/u/leifdenby)\
**Replies:** 5\
**Last updated:** [October 6, 2022, 10:16am UTC](https://discourse.julialang.org/t/rotr90-of-a-cuda-cuarray/88308 "2022-10-06T10:16:38Z")

</div>

I’m trying to implement a neural network which rotates the image within the layers of the network. My question is: is there a way to use something like Base.rotr90 on a CUDA.CuArray while disabling scalar indexing (CUDA.…

---

## [Anyone developing multinomial logistic regression?](https://discourse.julialang.org/t/anyone-developing-multinomial-logistic-regression/23222)

<div class="topic-metadata">

**Author:** [@tyleransom](https://discourse.julialang.org/u/tyleransom)\
**Replies:** 19\
**Last updated:** [October 6, 2022, 9:30am UTC](https://discourse.julialang.org/t/anyone-developing-multinomial-logistic-regression/23222 "2022-10-06T09:30:02Z")

</div>

Hi all, I’m looking to write a multinomial logistic regression function (including conditional logit). From what I can see, there is no extant package that can do this. Given the popularity of such a model, I’m surprise…

---

## [Difference between += and .+=](https://discourse.julialang.org/t/difference-between-and/88289)

<div class="topic-metadata">

**Author:** [@Fourier](https://discourse.julialang.org/u/Fourier)\
**Replies:** 5\
**Last updated:** [October 6, 2022, 9:28am UTC](https://discourse.julialang.org/t/difference-between-and/88289 "2022-10-06T09:28:28Z")

</div>

What is the difference between the += and the .+= operator in julia when adding two arrays, eg. x = \[1,2,3\]; y = \[4,5,6\] x+=y vs x.+=y?

---

## [Assigning array to a slice of another array](https://discourse.julialang.org/t/assigning-array-to-a-slice-of-another-array/88284)

<div class="topic-metadata">

**Author:** [@SiddhantDeshmukh](https://discourse.julialang.org/u/SiddhantDeshmukh)\
**Replies:** 6\
**Last updated:** [October 6, 2022, 8:19am UTC](https://discourse.julialang.org/t/assigning-array-to-a-slice-of-another-array/88284 "2022-10-06T08:19:24Z")

</div>

Hi, I’ve been trying to vectorize the following operation for i = 1:N arr\[i, :, :\] .= arr\[a, :, :\] end over the indices ‘i’ as @. arr\[b:c, :, :\] = arr\[a, :, :\] (where ‘b’ = 1, ‘c’ = N) such that all of the eleme…

---

## [Strange error when passing a DataFrame to pmap](https://discourse.julialang.org/t/strange-error-when-passing-a-dataframe-to-pmap/88316)

<div class="topic-metadata">

**Author:** [@mb96](https://discourse.julialang.org/u/mb96)\
**Replies:** 1\
**Last updated:** [October 6, 2022, 8:10am UTC](https://discourse.julialang.org/t/strange-error-when-passing-a-dataframe-to-pmap/88316 "2022-10-06T08:10:06Z")

</div>

Hi there! I am having an error when parallelizing my code with the Distributed library from which I use pmap. The following code might seem a bit strange but it is a (as much as possible) simplification of what I was run…

---

## [Julia internship @ Airbus in Munich](https://discourse.julialang.org/t/julia-internship-airbus-in-munich/86634)

<div class="topic-metadata">

**Author:** [@kschertler](https://discourse.julialang.org/u/kschertler)\
**Replies:** 8\
**Last updated:** [October 6, 2022, 7:52am UTC](https://discourse.julialang.org/t/julia-internship-airbus-in-munich/86634 "2022-10-06T07:52:59Z")

</div>

We currently have an open internship position inside an AI research team at Airbus in Munich. Well…, yes…, programming is done in Julia :heart\_eyes:. Feel free to have a look: Intern (f/m/d) Julia for Artificial Intellig…

---

## [Julia 1.6.7 LTS Pkg.add(“Gtk”) on Windows 10](https://discourse.julialang.org/t/julia-1-6-7-lts-pkg-add-gtk-on-windows-10/88315)

<div class="topic-metadata">

**Author:** [@Pilbum](https://discourse.julialang.org/u/Pilbum)\
**Replies:** 2\
**Last updated:** [October 6, 2022, 4:26am UTC](https://discourse.julialang.org/t/julia-1-6-7-lts-pkg-add-gtk-on-windows-10/88315 "2022-10-06T04:26:39Z")

</div>

I asked the same question on New to Julia category and just repeat here. I am trying to install Gtk, but got an error message as below. ERROR: Unable to automatically install ‘adwaita\_icon\_theme’ from ‘C:\\Users\\me.juli…

---

## [SDE simulation using DifferentialEquations.jl SDE solver RKMilGeneral](https://discourse.julialang.org/t/sde-simulation-using-differentialequations-jl-sde-solver-rkmilgeneral/88312)

<div class="topic-metadata">

**Author:** [@Max\_Beez](https://discourse.julialang.org/u/Max_Beez)\
**Replies:** 3\
**Last updated:** [October 6, 2022, 2:20am UTC](https://discourse.julialang.org/t/sde-simulation-using-differentialequations-jl-sde-solver-rkmilgeneral/88312 "2022-10-06T02:20:55Z")

</div>

I am simulating an SDE and using scatter! to plot the results. I set dt = 0.1 with timespan 0.0 to 1.0, then if use EM() as the SDE solver method I get 10 equally spaced (in-time) scatter points on the plot. Howeve…

---

## [How do I use LsqFit to fit points with an associated error?](https://discourse.julialang.org/t/how-do-i-use-lsqfit-to-fit-points-with-an-associated-error/88291)

<div class="topic-metadata">

**Author:** [@ultrapoci](https://discourse.julialang.org/u/ultrapoci)\
**Replies:** 2\
**Last updated:** [October 5, 2022, 8:32pm UTC](https://discourse.julialang.org/t/how-do-i-use-lsqfit-to-fit-points-with-an-associated-error/88291 "2022-10-05T20:32:07Z")

</div>

I have these points I want to fit: x y err 24.0 0.0386341 4.29118e-5 24.33 0.03952 2.10541e-5 24.66 0.0398329 1.76137e-5 25.0 0.0399503 1.75643e-5 25.33 0.0399654 1.63191e-5 25.66 0.0398724 …

---

## [Downloading Julia on a host system through the terminal](https://discourse.julialang.org/t/downloading-julia-on-a-host-system-through-the-terminal/88303)

<div class="topic-metadata">

**Author:** [@mb96](https://discourse.julialang.org/u/mb96)\
**Replies:** 3\
**Last updated:** [October 5, 2022, 6:46pm UTC](https://discourse.julialang.org/t/downloading-julia-on-a-host-system-through-the-terminal/88303 "2022-10-05T18:46:00Z")

</div>

Hi there, I am using a host Mac computer as a cluster (through remote controlling) and I want to install the latest Julia version on it but it has to be done through the terminal. Theres an old version installed in the …

---

## [Plots + PlotlyJS + LaTeX](https://discourse.julialang.org/t/plots-plotlyjs-latex/38250)

<div class="topic-metadata">

**Author:** [@Oto\_Brzobohaty](https://discourse.julialang.org/u/Oto_Brzobohaty)\
**Replies:** 14\
**Last updated:** [October 5, 2022, 3:46pm UTC](https://discourse.julialang.org/t/plots-plotlyjs-latex/38250 "2022-10-05T15:46:28Z")

</div>

I love PlotlyJS interactivity mainly in Jupyter notebook or VS Code Plot pane, on the other hand, I had always problems with latex in labels. Recently, I noticed that in one of my julia environment (Julia 1.3.1, jupyter…

---

## [Exponent operator failing for large exponents](https://discourse.julialang.org/t/exponent-operator-failing-for-large-exponents/88286)

<div class="topic-metadata">

**Author:** [@mb96](https://discourse.julialang.org/u/mb96)\
**Replies:** 11\
**Last updated:** [October 5, 2022, 3:39pm UTC](https://discourse.julialang.org/t/exponent-operator-failing-for-large-exponents/88286 "2022-10-05T15:39:25Z")

</div>

Hi there I tried exponentiating 2 to large powers with the ^ operator but when exponent gets large I get a zero.

---

## [How to get the updated coordinates of vertices in the interaction with mouse using Makie.jl](https://discourse.julialang.org/t/how-to-get-the-updated-coordinates-of-vertices-in-the-interaction-with-mouse-using-makie-jl/87900)

<div class="topic-metadata">

**Author:** [@Firstname\_Lastname](https://discourse.julialang.org/u/Firstname_Lastname)\
**Replies:** 2\
**Last updated:** [October 5, 2022, 3:01pm UTC](https://discourse.julialang.org/t/how-to-get-the-updated-coordinates-of-vertices-in-the-interaction-with-mouse-using-makie-jl/87900 "2022-10-05T15:01:49Z")

</div>

From the tutorial Interactive data visualizations with Makie.jl | Simon Danisch & Julius Krumbiegel | JuliaCon 2022 - YouTube I learned that the package Makie.jl is very nice and powerful. It can quickly update the plo…

---

## [Missing imputation: comparision of BetaML, Python SKL, R Mice](https://discourse.julialang.org/t/missing-imputation-comparision-of-betaml-python-skl-r-mice/72447)

<div class="topic-metadata">

**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 1\
**Last updated:** [October 5, 2022, 2:58pm UTC](https://discourse.julialang.org/t/missing-imputation-comparision-of-betaml-python-skl-r-mice/72447 "2022-10-05T14:58:51Z")

</div>

Hello, I did a small benchmarking of Julia BetaML (predictMissing - that uses GMM - and custom random forest prediction), SciKitLearn SI, II and KK-based imputators and R Mice, using the default values for each. Below a…

---

## [Can gpu calculation accelerates this function?](https://discourse.julialang.org/t/can-gpu-calculation-accelerates-this-function/88295)

<div class="topic-metadata">

**Author:** [@Brian1](https://discourse.julialang.org/u/Brian1)\
**Replies:** 2\
**Last updated:** [October 5, 2022, 2:15pm UTC](https://discourse.julialang.org/t/can-gpu-calculation-accelerates-this-function/88295 "2022-10-05T14:15:55Z")

</div>

I don’t have gpu on hands for now, and I am curious that weather this function can be accelerated by applying Gpu calculation. I used to think gpu can only speed up function like + - \* .... In my experience, this kind of…

---

## [@profview not defined - REPL not connected to VSCode](https://discourse.julialang.org/t/profview-not-defined-repl-not-connected-to-vscode/88138)

<div class="topic-metadata">

**Author:** [@Pablo](https://discourse.julialang.org/u/Pablo)\
**Replies:** 12\
**Last updated:** [October 5, 2022, 2:10pm UTC](https://discourse.julialang.org/t/profview-not-defined-repl-not-connected-to-vscode/88138 "2022-10-05T14:10:44Z")

</div>

I´m running Julia inside a VSCode devcontainer. I open a new bash window and do: julia julia\> using Main: @profview ERROR: UndefVarError: @profview not defined but if I start the REPL using VSCode’s command palette co…

---

## [Text Analysis API Error](https://discourse.julialang.org/t/text-analysis-api-error/88262)

<div class="topic-metadata">

**Author:** [@nosewitz](https://discourse.julialang.org/u/nosewitz)\
**Replies:** 2\
**Last updated:** [October 5, 2022, 1:36pm UTC](https://discourse.julialang.org/t/text-analysis-api-error/88262 "2022-10-05T13:36:05Z")

</div>

I am attempting to make a model for sensitivity analysis by only keeping the intersection of tokens between a test set and a training set of documents. To do this I am converting both sets of documents into Corpus and fi…

---

## [NLSolve vs fsolve (matlab): What am I doing wrong?](https://discourse.julialang.org/t/nlsolve-vs-fsolve-matlab-what-am-i-doing-wrong/88095)

<div class="topic-metadata">

**Author:** [@Outeirom](https://discourse.julialang.org/u/Outeirom)\
**Replies:** 5\
**Last updated:** [October 5, 2022, 1:34pm UTC](https://discourse.julialang.org/t/nlsolve-vs-fsolve-matlab-what-am-i-doing-wrong/88095 "2022-10-05T13:34:26Z")

</div>

So, I have a code in matlab and I am trying to translate it to Julia. Can anyone help me an tell me what am I doing wrong? Basically it is a function and I need to use fsolve/ NLSolve. I put first fig below matlab codes…

---

## [Random Segmentation Fault on GitHub tests](https://discourse.julialang.org/t/random-segmentation-fault-on-github-tests/88172)

<div class="topic-metadata">

**Author:** [@markowkes](https://discourse.julialang.org/u/markowkes)\
**Replies:** 4\
**Last updated:** [October 5, 2022, 12:54pm UTC](https://discourse.julialang.org/t/random-segmentation-fault-on-github-tests/88172 "2022-10-05T12:54:19Z")

</div>

A package I have developed randomly fails to pass github tests due to a segmentation fault. For example, this test failed: https://github.com/markowkes/Biofilm.jl/actions/runs/3175253204/jobs/5173336213. I have seen a …

---

## [How can I access struct fields](https://discourse.julialang.org/t/how-can-i-access-struct-fields/88259)

<div class="topic-metadata">

**Author:** [@ali1](https://discourse.julialang.org/u/ali1)\
**Replies:** 11\
**Last updated:** [October 5, 2022, 12:53pm UTC](https://discourse.julialang.org/t/how-can-i-access-struct-fields/88259 "2022-10-05T12:53:37Z")

</div>

Hello Everyone! I am new to Julia and I am trying to create a function that checks if it is possible to insert a request in between 2 reservations. First I want to check the (Time) interval between the reservations, and …

---

## [Loading .svg into Plot for further processing](https://discourse.julialang.org/t/loading-svg-into-plot-for-further-processing/88252)

<div class="topic-metadata">

**Author:** [@Nash](https://discourse.julialang.org/u/Nash)\
**Replies:** 8\
**Last updated:** [October 5, 2022, 11:40am UTC](https://discourse.julialang.org/t/loading-svg-into-plot-for-further-processing/88252 "2022-10-05T11:40:19Z")

</div>

I am working on an image that combines a chart, white space, and text. I am using Plot for this. I start by producing the chart and then save it as a .png image. Then I load the image and add various designs like white s…

---

## [Transparancy in colormap / removing contour level](https://discourse.julialang.org/t/transparancy-in-colormap-removing-contour-level/88283)

<div class="topic-metadata">

**Author:** [@Janssena](https://discourse.julialang.org/u/Janssena)\
**Replies:** 0\
**Last updated:** [October 5, 2022, 10:53am UTC](https://discourse.julialang.org/t/transparancy-in-colormap-removing-contour-level/88283 "2022-10-05T10:53:54Z")

</div>

Hey All, I am trying to create a contourf() plot where the lowest contour level is not being colored. I want to overlap multiple contour plots so I do not want the lowest level of contour 2 to overlap contour 1. I am u…

---

## [Recommended way to extract logprob and build gradients in Turing.jl?](https://discourse.julialang.org/t/recommended-way-to-extract-logprob-and-build-gradients-in-turing-jl/88279)

<div class="topic-metadata">

**Author:** [@svilupp](https://discourse.julialang.org/u/svilupp)\
**Replies:** 2\
**Last updated:** [October 5, 2022, 11:19am UTC](https://discourse.julialang.org/t/recommended-way-to-extract-logprob-and-build-gradients-in-turing-jl/88279 "2022-10-05T11:19:15Z")

</div>

Hi everyone, What is the recommended way to extract the log density and build gradients from a Turing model? (DynamicPPL) Use cases: eg, feeding it to something like Pathfinder.jl (if it didn’t Turing API) or novel sam…

---

## [Neural Nets training with multiple Chains Lux.jl and CUDA.jl](https://discourse.julialang.org/t/neural-nets-training-with-multiple-chains-lux-jl-and-cuda-jl/88167)

<div class="topic-metadata">

**Author:** [@LeoCott](https://discourse.julialang.org/u/LeoCott)\
**Replies:** 5\
**Last updated:** [October 5, 2022, 10:30am UTC](https://discourse.julialang.org/t/neural-nets-training-with-multiple-chains-lux-jl-and-cuda-jl/88167 "2022-10-05T10:30:51Z")

</div>

Hi all, I am a GPU beginner so I probably ask something obvious. I defined a neural net with four Lux.jl chains: input\_ = 2 n = 20 chain1 = Lux.Chain(Dense(input\_,n,Lux.σ),Dense(n,n,Lux.σ),Dense(n,n,Lux.σ),Dense(n,n,L…

---

## [Arithmetic with types](https://discourse.julialang.org/t/arithmetic-with-types/88278)

<div class="topic-metadata">

**Author:** [@prittjam](https://discourse.julialang.org/u/prittjam)\
**Replies:** 1\
**Last updated:** [October 5, 2022, 10:06am UTC](https://discourse.julialang.org/t/arithmetic-with-types/88278 "2022-10-05T10:06:41Z")

</div>

How can I add types that are integers and pass them along to other parameterized types? e.g., const PointRpN{N \<: Integer, T \<: AbstractFloat} = Euclidean.PointNd{N+1,T} const PointRp2{T \<: AbstractFloat} = PointRpN{2…

---

## [Annotations in Plot save as black when image format is PNG, although the REPL shows the correct custom color](https://discourse.julialang.org/t/annotations-in-plot-save-as-black-when-image-format-is-png-although-the-repl-shows-the-correct-custom-color/88277)

<div class="topic-metadata">

**Author:** [@Nash](https://discourse.julialang.org/u/Nash)\
**Replies:** 0\
**Last updated:** [October 5, 2022, 8:59am UTC](https://discourse.julialang.org/t/annotations-in-plot-save-as-black-when-image-format-is-png-although-the-repl-shows-the-correct-custom-color/88277 "2022-10-05T08:59:06Z")

</div>

When I annotate a plot in a custom, non-black, color, and save it as PNG, the image saved does not show the custom colored text, but shows it in black. Please see the following example: Has anyone encountered this probl…

---

## [Is it possible to study the Wizard Book in Julia?](https://discourse.julialang.org/t/is-it-possible-to-study-the-wizard-book-in-julia/88232)

<div class="topic-metadata">

**Author:** [@VincentFerrigan](https://discourse.julialang.org/u/VincentFerrigan)\
**Replies:** 6\
**Last updated:** [October 5, 2022, 6:17am UTC](https://discourse.julialang.org/t/is-it-possible-to-study-the-wizard-book-in-julia/88232 "2022-10-05T06:17:13Z")

</div>

Hi I would love to study SICP (and even HtDP) one day. It would be magnificent if it was possible to do it all in the Julia REPL, Pluto and/or Jupyter. I wonder if it’s possible to write Scheme code in Julia. Would it…

---

## [Isstructtype()](https://discourse.julialang.org/t/isstructtype/88268)

<div class="topic-metadata">

**Author:** [@Lincoln\_Hannah](https://discourse.julialang.org/u/Lincoln_Hannah)\
**Replies:** 5\
**Last updated:** [October 5, 2022, 5:49am UTC](https://discourse.julialang.org/t/isstructtype/88268 "2022-10-05T05:49:29Z")

</div>

Is it possible to do something like function my\_func( x::I ) where isstructtype(I) #function body end

---

## [How to substitute variable in expression contains its derivative also](https://discourse.julialang.org/t/how-to-substitute-variable-in-expression-contains-its-derivative-also/88241)

<div class="topic-metadata">

**Author:** [@Starpower\_Power](https://discourse.julialang.org/u/Starpower_Power)\
**Replies:** 2\
**Last updated:** [October 4, 2022, 11:35pm UTC](https://discourse.julialang.org/t/how-to-substitute-variable-in-expression-contains-its-derivative-also/88241 "2022-10-04T23:35:35Z")

</div>

using SymPy using PyCall sp = pyimport("sympy") t1 = sp.Function("theta\_1")(t) f = t1^2 +t1 df = sp.diff(f,t) # so df = 2\*t1\*(d(t1)/d(t))+ (d(t1)/d(t)) # if substitution done of t1 value that is t1 = 2 s = df.subs(\[(…

[Previous page](https://discourse.julialang.org/latest.md?page=902)

[Next page](https://discourse.julialang.org/latest.md?page=904)