# Latest

**URL:** https://discourse.julialang.org/latest.md?page=987

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

**Page:** 988

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## [Does FunctionWrappers.jl support parametric polymorphism?](https://discourse.julialang.org/t/does-functionwrappers-jl-support-parametric-polymorphism/66408)

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**Author:** [@jzr](https://discourse.julialang.org/u/jzr)\
**Replies:** 3\
**Last updated:** [July 8, 2022, 7:54pm UTC](https://discourse.julialang.org/t/does-functionwrappers-jl-support-parametric-polymorphism/66408 "2022-07-08T19:54:35Z")

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julia\> (FunctionWrapper{T, T} where T)(x -\> x + 1) ERROR: MethodError: no method matching (FunctionWrapper{T, T} where T)(::var"#3#4") julia\> (FunctionWrapper{T, Tuple{T}} where T)(x -\> x + 1) ERROR: MethodError: no met…

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## [Efficiently passing a set of constants to a function](https://discourse.julialang.org/t/efficiently-passing-a-set-of-constants-to-a-function/72248)

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**Author:** [@bgctw](https://discourse.julialang.org/u/bgctw)\
**Replies:** 21\
**Last updated:** [July 8, 2022, 7:25pm UTC](https://discourse.julialang.org/t/efficiently-passing-a-set-of-constants-to-a-function/72248 "2022-07-08T19:25:15Z")

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I am using physical constants in a function in a package. The access to these constants should be fast, best the compiler could replace the values in the lower-level-code. I can actually achieve this by using global con…

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## [Moving to juliadb from dataframes and getting error joining tables, dataframes join ok](https://discourse.julialang.org/t/moving-to-juliadb-from-dataframes-and-getting-error-joining-tables-dataframes-join-ok/83894)

<div class="topic-metadata">

**Author:** [@bww00](https://discourse.julialang.org/u/bww00)\
**Replies:** 1\
**Last updated:** [July 8, 2022, 7:21pm UTC](https://discourse.julialang.org/t/moving-to-juliadb-from-dataframes-and-getting-error-joining-tables-dataframes-join-ok/83894 "2022-07-08T19:21:54Z")

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Moving to juliadb from dataframes and getting error joining 2 tables. ERROR: LoadError: UndefRefError: access to undefined reference error is on the join statement tables load ok. Any help appreciated code and error…

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## [Hexadecimal Float64 creation](https://discourse.julialang.org/t/hexadecimal-float64-creation/83936)

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**Author:** [@uje](https://discourse.julialang.org/u/uje)\
**Replies:** 4\
**Last updated:** [July 8, 2022, 7:00pm UTC](https://discourse.julialang.org/t/hexadecimal-float64-creation/83936 "2022-07-08T19:00:08Z")

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x = 0x.4p-1 0.125 What is the maths behind it, because I know 0.4 \* 2^-1 = 0.2 I’m confused as to why that returns 0.125 in Julia, please enlighten me if I’m missing something

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## [Manipulating vectors with logsumexp](https://discourse.julialang.org/t/manipulating-vectors-with-logsumexp/83955)

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**Author:** [@samerb](https://discourse.julialang.org/u/samerb)\
**Replies:** 2\
**Last updated:** [July 8, 2022, 5:28pm UTC](https://discourse.julialang.org/t/manipulating-vectors-with-logsumexp/83955 "2022-07-08T17:28:43Z")

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I have an n-dimensional vector \\delta and I would like to compute the following vector expression. \\left\[ \\log \\left( \\sum\_{i=1}^n \\exp(\\delta\_i) \\right) - \\log \\left( \\sum\_{i \\neq j} \\exp(\\delta\_i) \\right) \\right\]\_{j=…

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## [ML+Optimization consulting/contracting](https://discourse.julialang.org/t/ml-optimization-consulting-contracting/82900)

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**Author:** [@DanielV](https://discourse.julialang.org/u/DanielV)\
**Replies:** 0\
**Last updated:** [June 17, 2022, 1:16am UTC](https://discourse.julialang.org/t/ml-optimization-consulting-contracting/82900 "2022-06-17T01:16:18Z")

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I’d love to help your company: Select, invent, implement algorithms and methods in Julia (or Python/Rust, if that’s the need) Give you the help you need to go faster: ML for the SWE, machine affinity for the scientists…

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## [Internship @ Airbus in Munich](https://discourse.julialang.org/t/internship-airbus-in-munich/83234)

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**Author:** [@ckeimel](https://discourse.julialang.org/u/ckeimel)\
**Replies:** 0\
**Last updated:** [June 23, 2022, 11:46am UTC](https://discourse.julialang.org/t/internship-airbus-in-munich/83234 "2022-06-23T11:46:01Z")

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We currently have an open position in Airbus Central Research & Technology (XRD) with Airbus Defence and Space in Taufkirchen, close to Munich. If you are interested or know someone who might be, check the details below…

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## [Research Software Engineer at University of Edinburgh](https://discourse.julialang.org/t/research-software-engineer-at-university-of-edinburgh/83332)

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**Author:** [@Andreayeong](https://discourse.julialang.org/u/Andreayeong)\
**Replies:** 0\
**Last updated:** [June 25, 2022, 10:30am UTC](https://discourse.julialang.org/t/research-software-engineer-at-university-of-edinburgh/83332 "2022-06-25T10:30:55Z")

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1-year post for a research software engineer to join a research team in biomedical computation at the University of Edinburgh. Ideally, we are looking for candidates with proficiency in Julia, experience with backend and…

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## [PhD position on two-phase flow modelling at ISTeP in Paris](https://discourse.julialang.org/t/phd-position-on-two-phase-flow-modelling-at-istep-in-paris/83294)

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**Author:** [@luraess](https://discourse.julialang.org/u/luraess)\
**Replies:** 0\
**Last updated:** [June 24, 2022, 8:19am UTC](https://discourse.julialang.org/t/phd-position-on-two-phase-flow-modelling-at-istep-in-paris/83294 "2022-06-24T08:19:11Z")

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Announcing a fully founded PhD position opened at ISTeP, Sorbonne University in the centre of Paris. The PhD topic investigates two-phase flow modelling applied to rare metal pegmatites and granit. The modelling tasks w…

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## [Senior and Principal Software Engineer Roles at Optimal Agriculture - UK](https://discourse.julialang.org/t/senior-and-principal-software-engineer-roles-at-optimal-agriculture-uk/83558)

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**Author:** [@mmiller](https://discourse.julialang.org/u/mmiller)\
**Replies:** 0\
**Last updated:** [June 30, 2022, 9:05am UTC](https://discourse.julialang.org/t/senior-and-principal-software-engineer-roles-at-optimal-agriculture-uk/83558 "2022-06-30T09:05:38Z")

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We have several software engineer roles (Senior and Principal) at Optimal Agriculture, London, UK. Our mission is to deploy autonomous, sustainable greenhouses outside every city on earth. We are a growing startup backe…

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## [Autoreload Python packages/modules](https://discourse.julialang.org/t/autoreload-python-packages-modules/83912)

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**Author:** [@martinmestre](https://discourse.julialang.org/u/martinmestre)\
**Replies:** 4\
**Last updated:** [July 8, 2022, 5:37pm UTC](https://discourse.julialang.org/t/autoreload-python-packages-modules/83912 "2022-07-08T17:37:01Z")

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Hello, is it possible to autoreload python modules (my own files.py) that I have recently modified without having to restart julia? I am using PyCall but I can change to PythonCall if needed. This is what I am doing: p…

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## [Parallelizing Multiple Workers for File Operations](https://discourse.julialang.org/t/parallelizing-multiple-workers-for-file-operations/83951)

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**Author:** [@TheCedarPrince](https://discourse.julialang.org/u/TheCedarPrince)\
**Replies:** 1\
**Last updated:** [July 8, 2022, 4:41pm UTC](https://discourse.julialang.org/t/parallelizing-multiple-workers-for-file-operations/83951 "2022-07-08T16:41:27Z")

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Hi all, This is my first time trying this out but here is a problem and what I am trying to do and what I am stuck on trying to do: Problem: I have many big files (200+, 50 - 100GB each) that I am going to read out. I…

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## [Unable to convert Linspace to Range in a function](https://discourse.julialang.org/t/unable-to-convert-linspace-to-range-in-a-function/83943)

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**Author:** [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)\
**Replies:** 4\
**Last updated:** [July 8, 2022, 3:45pm UTC](https://discourse.julialang.org/t/unable-to-convert-linspace-to-range-in-a-function/83943 "2022-07-08T15:45:58Z")

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Hi all, I want to plot partitions of Riemann Sums from this blog: https://julialang.org/blog/2017/03/piday/ The problem is since it is from 2017 article, it is using linspace, I read around and see it is replaced by ra…

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## [Concise error messages in VS Code](https://discourse.julialang.org/t/concise-error-messages-in-vs-code/79641)

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**Author:** [@chadagreene](https://discourse.julialang.org/u/chadagreene)\
**Replies:** 2\
**Last updated:** [July 8, 2022, 3:23pm UTC](https://discourse.julialang.org/t/concise-error-messages-in-vs-code/79641 "2022-07-08T15:23:40Z")

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Is there a way to reduce the verbosity of error messages in VS Code notebooks? I’m currently learning Julia, making lots of mistakes along the way, and my first impression is that Julia/VS Code horribly overreacts to ev…

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## [Interpolate variables into latex matrix in Pluto](https://discourse.julialang.org/t/interpolate-variables-into-latex-matrix-in-pluto/83698)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 3\
**Last updated:** [July 8, 2022, 2:48pm UTC](https://discourse.julialang.org/t/interpolate-variables-into-latex-matrix-in-pluto/83698 "2022-07-08T14:48:16Z")

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Hi all, As shown in the screen shot, I would like to reference variables inside a LaTeX matrix. Here is the code I am using. Any help would be greatly appreciated.

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## [How to Draw Polygon inside circle and calculate its area?](https://discourse.julialang.org/t/how-to-draw-polygon-inside-circle-and-calculate-its-area/83900)

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**Author:** [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)\
**Replies:** 3\
**Last updated:** [July 8, 2022, 12:57pm UTC](https://discourse.julialang.org/t/how-to-draw-polygon-inside-circle-and-calculate-its-area/83900 "2022-07-08T12:57:50Z")

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I want to know how to create polygons inside circle and calculate its area, just like the image below:

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## [Debugging code in Pluto.jl notebook](https://discourse.julialang.org/t/debugging-code-in-pluto-jl-notebook/83945)

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**Author:** [@Naadiyaar](https://discourse.julialang.org/u/Naadiyaar)\
**Replies:** 1\
**Last updated:** [July 8, 2022, 12:24pm UTC](https://discourse.julialang.org/t/debugging-code-in-pluto-jl-notebook/83945 "2022-07-08T12:24:02Z")

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Hello there, I’m trying to create a simple application in Pluto. As I use Pluto for all my DS work, and it is my main code writing tool in Julia, thought it would be good to use it for software development, but I’m faci…

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## [Divide a matrix into 4 submatrices](https://discourse.julialang.org/t/divide-a-matrix-into-4-submatrices/83856)

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**Author:** [@JosieG](https://discourse.julialang.org/u/JosieG)\
**Replies:** 6\
**Last updated:** [July 8, 2022, 11:20am UTC](https://discourse.julialang.org/t/divide-a-matrix-into-4-submatrices/83856 "2022-07-08T11:20:54Z")

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Hi, I’m given a 2\*38 matrix. -7.002 -6.94768 -6.92167 -6.85372 … -3.67384 -3.61184 -3.51171 -1.00187 -1.15017 -1.08179 -1.09073 -0.389809 -0.730911 -0.813239 And I want to get four submatrices. T…

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## [How to draw area below a function at certain interval?](https://discourse.julialang.org/t/how-to-draw-area-below-a-function-at-certain-interval/83895)

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**Author:** [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)\
**Replies:** 2\
**Last updated:** [July 8, 2022, 11:14am UTC](https://discourse.julialang.org/t/how-to-draw-area-below-a-function-at-certain-interval/83895 "2022-07-08T11:14:51Z")

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Hi all, how do we draw an area like below (definite integral)? and how to make the result function of the area becomes in the same box like label? This is my code: using Plots, LaTeXStrings gr() function Area(f, a…

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## [Getkey for dictionaries with composite-typed values](https://discourse.julialang.org/t/getkey-for-dictionaries-with-composite-typed-values/83940)

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**Author:** [@taxodium](https://discourse.julialang.org/u/taxodium)\
**Replies:** 1\
**Last updated:** [July 8, 2022, 11:05am UTC](https://discourse.julialang.org/t/getkey-for-dictionaries-with-composite-typed-values/83940 "2022-07-08T11:05:53Z")

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Hi. I’m intermediate level in Julia. For some problem I want to solve, I have to define a custom composite type: struct NodeData presence\_cpu::AbstractVector{Bool} presence\_gpu::AbstractVector{Bool} mem\_…

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## [Getting around \`Zygote\` mutating array issue](https://discourse.julialang.org/t/getting-around-zygote-mutating-array-issue/83907)

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**Author:** [@pat-alt](https://discourse.julialang.org/u/pat-alt)\
**Replies:** 5\
**Last updated:** [July 8, 2022, 10:23am UTC](https://discourse.julialang.org/t/getting-around-zygote-mutating-array-issue/83907 "2022-07-08T10:23:45Z")

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I’m faced with the Mutating arrays is not supported error message and looking for ideas/help. In particular, I am trying to compute gradients of the following metric that measures diversity across a multi-dimensional arr…

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## [Dependent Sliders Using PlutoUI](https://discourse.julialang.org/t/dependent-sliders-using-plutoui/83941)

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**Author:** [@AliRahmjoo](https://discourse.julialang.org/u/AliRahmjoo)\
**Replies:** 0\
**Last updated:** [July 8, 2022, 10:18am UTC](https://discourse.julialang.org/t/dependent-sliders-using-plutoui/83941 "2022-07-08T10:18:21Z")

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Hello. Is there a way to build dependent sliders with PlutoUI in which adjusting one will dynamically change the others?

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## [Best practice to make sure Julia and third-party libraries use the same MKL?](https://discourse.julialang.org/t/best-practice-to-make-sure-julia-and-third-party-libraries-use-the-same-mkl/83938)

<div class="topic-metadata">

**Author:** [@jsjie](https://discourse.julialang.org/u/jsjie)\
**Replies:** 0\
**Last updated:** [July 8, 2022, 10:05am UTC](https://discourse.julialang.org/t/best-practice-to-make-sure-julia-and-third-party-libraries-use-the-same-mkl/83938 "2022-07-08T10:05:55Z")

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This might be a problem of broader scope, MKL is only an example. I’m using dftd4 library in my package, and a first attempt give me Intel MKL ERROR: Parameter 4 was incorrect on entry to DSYTRF. After some digging, I …

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## [\[ANN\] EllipticFunctions.jl](https://discourse.julialang.org/t/ann-ellipticfunctions-jl/83797)

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**Author:** [@\_stla](https://discourse.julialang.org/u/_stla)\
**Replies:** 9\
**Last updated:** [July 8, 2022, 9:46am UTC](https://discourse.julialang.org/t/ann-ellipticfunctions-jl/83797 "2022-07-08T09:46:31Z")

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I have soon finished the first version of Jacobi.jl: Jacobi theta functions and related functions. I still have to implement the Weierstrass sigma-function and the Weierstrass zeta-function, and the first version will be…

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## [Why does \`throw\` break type inference?](https://discourse.julialang.org/t/why-does-throw-break-type-inference/83934)

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**Author:** [@yiyuezhuo](https://discourse.julialang.org/u/yiyuezhuo)\
**Replies:** 2\
**Last updated:** [July 8, 2022, 9:25am UTC](https://discourse.julialang.org/t/why-does-throw-break-type-inference/83934 "2022-07-08T09:25:01Z")

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I’m researching SSA-IR, and I found that most types of Julia functions are determined by compile-time, as they’re converted to invoke type from call type with a MethodInstance in code\_typed. But there are still some call …

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## [Type stability in MixtureModels](https://discourse.julialang.org/t/type-stability-in-mixturemodels/83932)

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**Author:** [@LeeviL](https://discourse.julialang.org/u/LeeviL)\
**Replies:** 0\
**Last updated:** [July 8, 2022, 7:43am UTC](https://discourse.julialang.org/t/type-stability-in-mixturemodels/83932 "2022-07-08T07:43:36Z")

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Hi! I want to define a MixtureModel in which the component distributions might be from different families. While this piece of code works, the code is type unstable: using Distributions mixture = MixtureModel(\[Normal(-2…

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## [Optimization of function and solver DifferentialEquations.jl](https://discourse.julialang.org/t/optimization-of-function-and-solver-differentialequations-jl/83885)

<div class="topic-metadata">

**Author:** [@Sergey\_Novak](https://discourse.julialang.org/u/Sergey_Novak)\
**Replies:** 11\
**Last updated:** [July 8, 2022, 7:38am UTC](https://discourse.julialang.org/t/optimization-of-function-and-solver-differentialequations-jl/83885 "2022-07-08T07:38:02Z")

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How can i optimization this function and solver. I think I used all the optimizations I could from the documentation. I can not use dt or saveat. System have chaos and hyper chaos.

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## [Trying to write a package and cannot update it](https://discourse.julialang.org/t/trying-to-write-a-package-and-cannot-update-it/83821)

<div class="topic-metadata">

**Author:** [@roeya](https://discourse.julialang.org/u/roeya)\
**Replies:** 3\
**Last updated:** [July 8, 2022, 5:48am UTC](https://discourse.julialang.org/t/trying-to-write-a-package-and-cannot-update-it/83821 "2022-07-08T05:48:27Z")

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Hi, I have a created simple package, I do not want it to use github. So I have created it, and used Pkg dev function to add it to the project everything was fine till I added a new function to the package. I have upd…

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## [How to define this expression?](https://discourse.julialang.org/t/how-to-define-this-expression/83930)

<div class="topic-metadata">

**Author:** [@ivzktch99](https://discourse.julialang.org/u/ivzktch99)\
**Replies:** 1\
**Last updated:** [July 8, 2022, 3:46am UTC](https://discourse.julialang.org/t/how-to-define-this-expression/83930 "2022-07-08T03:46:04Z")

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Hello there I want to solve the following model using JuMP, Ipopt model = Model(Ipopt.Optimizer) n = 5 @variable(model, X\[1:n, 1:n\]) @variable(model, y\[1:n\]) u = ones(n) z = @expression(model, X \* u) expr = (1/factor…

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## [Application of umap](https://discourse.julialang.org/t/application-of-umap/83925)

<div class="topic-metadata">

**Author:** [@JosieG](https://discourse.julialang.org/u/JosieG)\
**Replies:** 0\
**Last updated:** [July 8, 2022, 1:21am UTC](https://discourse.julialang.org/t/application-of-umap/83925 "2022-07-08T01:21:32Z")

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Hi, I’m applying umap on my dataset. The reference is Updated Notebook with example of UMAP by davibarreira · Pull Request #44 · dillondaudert/UMAP.jl · GitHub and UMAP.jl/PlotMNIST.ipynb at master · dillondaudert/UMAP…

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