# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1395

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

**Page:** 1396

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## [Standard Git structure and update workflow for simple unregistered packages](https://discourse.julialang.org/t/standard-git-structure-and-update-workflow-for-simple-unregistered-packages/60972)

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**Author:** [@Nathan\_Boyer](https://discourse.julialang.org/u/Nathan_Boyer)\
**Replies:** 3\
**Last updated:** [May 11, 2021, 7:53pm UTC](https://discourse.julialang.org/t/standard-git-structure-and-update-workflow-for-simple-unregistered-packages/60972 "2021-05-11T19:53:58Z")

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I have a package hosted on Github that I work on in VSCode (both of which I am new to). It currently has master, feature-x, and bugfix-x branches that I created as well as some branches from CompatHelper. All branches ge…

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## [Literate programming style macros in Literate.jl or Weave.jl](https://discourse.julialang.org/t/literate-programming-style-macros-in-literate-jl-or-weave-jl/60967)

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**Author:** [@Shuvomoy\_Das\_Gupta](https://discourse.julialang.org/u/Shuvomoy_Das_Gupta)\
**Replies:** 2\
**Last updated:** [May 11, 2021, 7:24pm UTC](https://discourse.julialang.org/t/literate-programming-style-macros-in-literate-jl-or-weave-jl/60967 "2021-05-11T19:24:35Z")

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Dear All, Is there any way of implementing “literate programming style macro” in Literate.jl or Weave.jl? My goal is to write a tutorial-style literate program in a logical order for the human reader. For example: # He…

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## [Thread-parallel reduce(vcat, ...) performance issues when providing init](https://discourse.julialang.org/t/thread-parallel-reduce-vcat-performance-issues-when-providing-init/60955)

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**Author:** [@cgeoga](https://discourse.julialang.org/u/cgeoga)\
**Replies:** 2\
**Last updated:** [May 11, 2021, 7:15pm UTC](https://discourse.julialang.org/t/thread-parallel-reduce-vcat-performance-issues-when-providing-init/60955 "2021-05-11T19:15:11Z")

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Hey all— I’ve got a problem where I have a vec\_of\_vecs::Vector{Vector{T}} where the length is long and the length of each element is long. I’d love to use multithreading to do reduce(vcat, vec\_of\_vecs) more efficiently.…

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## [Problems with tuples in Statistics function](https://discourse.julialang.org/t/problems-with-tuples-in-statistics-function/60754)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 28\
**Last updated:** [May 11, 2021, 5:31pm UTC](https://discourse.julialang.org/t/problems-with-tuples-in-statistics-function/60754 "2021-05-11T17:31:21Z")

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using Statistics using Distributions x=\[1,2,3,4,5,6,7,8\] y=\[8,4,5,5,6,5,6,5\] function TwoSampleT2Test(X,Y) nx, p = size(X) ny, \_ = size(Y) δ = mean(X, dims=1) - mean(Y, dims=1) Sx = cov(X) Sy = cov(Y)…

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## [Combine CartesianIndices for effective CUDA kernels](https://discourse.julialang.org/t/combine-cartesianindices-for-effective-cuda-kernels/60958)

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**Author:** [@fedoroff](https://discourse.julialang.org/u/fedoroff)\
**Replies:** 4\
**Last updated:** [May 11, 2021, 5:30pm UTC](https://discourse.julialang.org/t/combine-cartesianindices-for-effective-cuda-kernels/60958 "2021-05-11T17:30:46Z")

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Suppose, I have a multidimensional array and I want to perform some operation along one of its axes. A sample generic code can look like this: s = (1, 2, 3, 4, 5) # shape of the array dim = 3 # dimension, along whic…

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## [Varargs function](https://discourse.julialang.org/t/varargs-function/60969)

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**Author:** [@gitboy16](https://discourse.julialang.org/u/gitboy16)\
**Replies:** 4\
**Last updated:** [May 11, 2021, 5:30pm UTC](https://discourse.julialang.org/t/varargs-function/60969 "2021-05-11T17:30:06Z")

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Hi, I have a function that takes a variable number of arguments like the following: function view(vargs...) out = DataFrame(vargs) out end I want the ouput of view to be the same as if I was using DataFrame, examp…

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## [Paper on mesh library in Julia](https://discourse.julialang.org/t/paper-on-mesh-library-in-julia/60957)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 4\
**Last updated:** [May 11, 2021, 4:49pm UTC](https://discourse.julialang.org/t/paper-on-mesh-library-in-julia/60957 "2021-05-11T16:49:32Z")

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A paper on the Julia mesh library MeshCore.jl appeared online. Disclaimer: The typesetting turned out to result in an unmitigated disaster. Miscommunication and carelessness of the Elsevier staff produced a very inferio…

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## [Dot-product of CuArray views is slow](https://discourse.julialang.org/t/dot-product-of-cuarray-views-is-slow/60953)

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**Author:** [@jlbosse](https://discourse.julialang.org/u/jlbosse)\
**Replies:** 10\
**Last updated:** [May 11, 2021, 4:37pm UTC](https://discourse.julialang.org/t/dot-product-of-cuarray-views-is-slow/60953 "2021-05-11T16:37:15Z")

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I have fairly simple function that iterates over the columns of a 2-dimensional CuArray , takes inner products of these columns and writes them to another matrix. I noticed that running this code on the GPU gave no speed…

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## [Using the Sockets Library](https://discourse.julialang.org/t/using-the-sockets-library/60448)

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**Author:** [@ligert123](https://discourse.julialang.org/u/ligert123)\
**Replies:** 13\
**Last updated:** [May 11, 2021, 4:32pm UTC](https://discourse.julialang.org/t/using-the-sockets-library/60448 "2021-05-11T16:32:58Z")

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Hello, i have been having trouble with the sockets library. For some reason when i write to a connection it doesnt succeed and instead hangs. I have no idea why this is happening, would anyone else have a clue? functio…

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## [Slack and the value of community heritage](https://discourse.julialang.org/t/slack-and-the-value-of-community-heritage/60559)

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**Author:** [@jzr](https://discourse.julialang.org/u/jzr)\
**Replies:** 37\
**Last updated:** [May 11, 2021, 4:31pm UTC](https://discourse.julialang.org/t/slack-and-the-value-of-community-heritage/60559 "2021-05-11T16:31:24Z")

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Lots of interesting and valuable conversations happen in Slack. These are often not bridged into other locations, and get permanently lost. There are alternatives: in addition to Discourse, the Julia Zulip provides chat …

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## [Reaching bounds of Distributions.Uniform()](https://discourse.julialang.org/t/reaching-bounds-of-distributions-uniform/60956)

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**Author:** [@goualard-f](https://discourse.julialang.org/u/goualard-f)\
**Replies:** 4\
**Last updated:** [May 11, 2021, 4:05pm UTC](https://discourse.julialang.org/t/reaching-bounds-of-distributions-uniform/60956 "2021-05-11T16:05:07Z")

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The documentation for Distributions.Uniform() states that it allows to draw a value in \[a,b\] (bounds included). Looking into the code, it seems that the rand() function from Base is used along with some affine transforma…

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## [Bad performance of DifferentialEquations.jl](https://discourse.julialang.org/t/bad-performance-of-differentialequations-jl/60923)

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**Author:** [@leonandonayre](https://discourse.julialang.org/u/leonandonayre)\
**Replies:** 11\
**Last updated:** [May 11, 2021, 4:01pm UTC](https://discourse.julialang.org/t/bad-performance-of-differentialequations-jl/60923 "2021-05-11T16:01:21Z")

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I am trying to solve a ODE with ModelingToolkit.jl, unfortunately I have been waiting for the result for more than 11 hours. I would to use Multithread, or some CUDA package in order to increase this awful performance, …

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## [Complicated GMM in Turing.jl - StackOverFlow error](https://discourse.julialang.org/t/complicated-gmm-in-turing-jl-stackoverflow-error/60876)

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**Author:** [@Michaela\_Maskova](https://discourse.julialang.org/u/Michaela_Maskova)\
**Replies:** 4\
**Last updated:** [May 11, 2021, 3:45pm UTC](https://discourse.julialang.org/t/complicated-gmm-in-turing-jl-stackoverflow-error/60876 "2021-05-11T15:45:20Z")

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Hey everyone, I’m trying to create a MGMM model from paper http://proceedings.mlr.press/v15/xiong11a/xiong11a.pdf. The idea is that I have a dataset D = \[G\_1, \\dots, G\_M\], where each group consists of vectors G\_M = \[x\_1…

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## [Checking condition on matrix/array element-wise modulo an integer](https://discourse.julialang.org/t/checking-condition-on-matrix-array-element-wise-modulo-an-integer/60954)

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**Author:** [@scipham](https://discourse.julialang.org/u/scipham)\
**Replies:** 0\
**Last updated:** [May 11, 2021, 2:05pm UTC](https://discourse.julialang.org/t/checking-condition-on-matrix-array-element-wise-modulo-an-integer/60954 "2021-05-11T14:05:47Z")

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My aim is to check whether a matrix (i.e. a 2D array) modulo d is Symplectic (see condition on wikipedia: Symplectic matrix - Wikipedia). That is, whether there is any Symplectic matrix in the set of matrices that are el…

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## [Julian way of writing a constructor](https://discourse.julialang.org/t/julian-way-of-writing-a-constructor/60943)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 4\
**Last updated:** [May 11, 2021, 2:18pm UTC](https://discourse.julialang.org/t/julian-way-of-writing-a-constructor/60943 "2021-05-11T14:18:12Z")

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I have the following code: using StaticArrays # Type definitions const MyFloat = Float32 const Vec3 = MVector{3, MyFloat} mutable struct State v\_wind::Vec3 # wind vector at the height of the kite v\_w…

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## [Julia syntax in antlr4?](https://discourse.julialang.org/t/julia-syntax-in-antlr4/60144)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 4\
**Last updated:** [May 11, 2021, 2:03pm UTC](https://discourse.julialang.org/t/julia-syntax-in-antlr4/60144 "2021-05-11T14:03:59Z")

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https://github.com/antlr/grammars-v4 In the above repo there is a bunch of antlr4 syntax definitions are languages but no Julia folder. Is anyone aware of an antlr4 syntax file for Julia?

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## [Video : Julia setup for beginner](https://discourse.julialang.org/t/video-julia-setup-for-beginner/56559)

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**Author:** [@LaurentPlagne](https://discourse.julialang.org/u/LaurentPlagne)\
**Replies:** 12\
**Last updated:** [May 11, 2021, 1:29pm UTC](https://discourse.julialang.org/t/video-julia-setup-for-beginner/56559 "2021-05-11T13:29:22Z")

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Hi, I prepared a short video showing a possible setup for Julia project developments. In particular I show how to: install and configure git and github install Julia install Revise.jl create a project with PkgSkeleto…

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## [Why do we need to prefix module name with Julia function sometimes to make it work?](https://discourse.julialang.org/t/why-do-we-need-to-prefix-module-name-with-julia-function-sometimes-to-make-it-work/60949)

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**Author:** [@shubh\_b](https://discourse.julialang.org/u/shubh_b)\
**Replies:** 1\
**Last updated:** [May 11, 2021, 1:19pm UTC](https://discourse.julialang.org/t/why-do-we-need-to-prefix-module-name-with-julia-function-sometimes-to-make-it-work/60949 "2021-05-11T13:19:21Z")

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As example, here is a DateTime object declared below using Dates module: julia\> using Dates julia\> dt = DateTime(2021, 05, 11, 18, 21, 50) 2021-05-11T18:21:50 We can find the Hour value of dt simply using hour() funct…

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## [DiffEqFlux: an error when using NN's that take both time and position as input](https://discourse.julialang.org/t/diffeqflux-an-error-when-using-nns-that-take-both-time-and-position-as-input/60937)

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**Author:** [@SvenDummer](https://discourse.julialang.org/u/SvenDummer)\
**Replies:** 6\
**Last updated:** [May 11, 2021, 11:29am UTC](https://discourse.julialang.org/t/diffeqflux-an-error-when-using-nns-that-take-both-time-and-position-as-input/60937 "2021-05-11T11:29:55Z")

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Hi everyone, I am new to the Julia programming language and ran into an error when programming. My problem: I would like to solve a ODE optimal control problem with a neural network based approach. I take the ODE and r…

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## [How can loop through a image folder?](https://discourse.julialang.org/t/how-can-loop-through-a-image-folder/60906)

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**Author:** [@assia855](https://discourse.julialang.org/u/assia855)\
**Replies:** 15\
**Last updated:** [May 11, 2021, 11:16am UTC](https://discourse.julialang.org/t/how-can-loop-through-a-image-folder/60906 "2021-05-11T11:16:44Z")

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I have a image folder I would like to loop through it. Can you share with me some useful code on how can I make it work please

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## [What should the default color space for \`YCbCr\` be?](https://discourse.julialang.org/t/what-should-the-default-color-space-for-ycbcr-be/60874)

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**Author:** [@kimikage](https://discourse.julialang.org/u/kimikage)\
**Replies:** 3\
**Last updated:** [May 11, 2021, 10:53am UTC](https://discourse.julialang.org/t/what-should-the-default-color-space-for-ycbcr-be/60874 "2021-05-11T10:53:54Z")

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Hi all, I (we) will make a clarification about the default color space for each color type in the next minor releases of ColorTypes.jl and Colors.jl. Of the color types defined in ColorTypes.jl, the definition of YCbCr …

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## [Code for Thought podcast episodes about Julia](https://discourse.julialang.org/t/code-for-thought-podcast-episodes-about-julia/60104)

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**Author:** [@giordano](https://discourse.julialang.org/u/giordano)\
**Replies:** 1\
**Last updated:** [May 11, 2021, 9:24am UTC](https://discourse.julialang.org/t/code-for-thought-podcast-episodes-about-julia/60104 "2021-05-11T09:24:58Z")

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Code for Thought is a podcast series about research software engineering hosted by my colleague Peter Schmidt and supported by the UK Society of Research Software Engineering. The last episode of the series is dedicated…

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## [Communicating with Sonic Pi using UDP sockets](https://discourse.julialang.org/t/communicating-with-sonic-pi-using-udp-sockets/60820)

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**Author:** [@cormullion](https://discourse.julialang.org/u/cormullion)\
**Replies:** 2\
**Last updated:** [May 11, 2021, 9:04am UTC](https://discourse.julialang.org/t/communicating-with-sonic-pi-using-udp-sockets/60820 "2021-05-11T09:04:48Z")

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I found the Sonic PI music synthesiser recently, and had fun playing with it (and the language is Ruby which is quite nice). I wondered whether it would be possible to use Julia to send OSC (Open Sound Control) instructi…

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## [Memory is not freed with CUDA and two REPLs](https://discourse.julialang.org/t/memory-is-not-freed-with-cuda-and-two-repls/60706)

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**Author:** [@roflmaostc](https://discourse.julialang.org/u/roflmaostc)\
**Replies:** 8\
**Last updated:** [May 7, 2021, 5:03pm UTC](https://discourse.julialang.org/t/memory-is-not-freed-with-cuda-and-two-repls/60706 "2021-05-07T17:03:02Z")

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Hey, I observed that on Julia 1.6.1 and CUDA 3.1.0 (and 2.6.3), I’m accumulating memory (with point wise multiplications) that I can only free when I close the REPL. I also track usage with nvidia-smi and initially ìt …

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## [\[NLsolve\] Providing the Jacobian of a system when variables are provided in an Array?](https://discourse.julialang.org/t/nlsolve-providing-the-jacobian-of-a-system-when-variables-are-provided-in-an-array/60823)

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**Author:** [@dadada\_dadada](https://discourse.julialang.org/u/dadada_dadada)\
**Replies:** 6\
**Last updated:** [May 11, 2021, 5:53am UTC](https://discourse.julialang.org/t/nlsolve-providing-the-jacobian-of-a-system-when-variables-are-provided-in-an-array/60823 "2021-05-11T05:53:41Z")

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When solving systems of equation, sometimes, it’s better to have the variables in Array format, instead of a vector. That said, can we provide multidimensional Jacobians to the solvers of the NLsolve package? For examp…

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## [Broadcast type mismatch](https://discourse.julialang.org/t/broadcast-type-mismatch/60848)

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**Author:** [@cepheid](https://discourse.julialang.org/u/cepheid)\
**Replies:** 3\
**Last updated:** [May 10, 2021, 6:22am UTC](https://discourse.julialang.org/t/broadcast-type-mismatch/60848 "2021-05-10T06:22:15Z")

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In the following code import Base: ^ struct cccbbb v::Matrix{Float64} end ^(cb::cccbbb, p::Int) = cb.v^p Base.Broadcast.broadcastable(cb::cccbbb) = Ref(cb) n = 5 r = LinRange(0.0, 10.0, 5) cb = cccbbb(rand(n,n)) …

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## [Disassociate parameter or variable from a model in JuMP](https://discourse.julialang.org/t/disassociate-parameter-or-variable-from-a-model-in-jump/60851)

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**Author:** [@path-doc](https://discourse.julialang.org/u/path-doc)\
**Replies:** 6\
**Last updated:** [May 11, 2021, 12:37am UTC](https://discourse.julialang.org/t/disassociate-parameter-or-variable-from-a-model-in-jump/60851 "2021-05-11T00:37:46Z")

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Suppose I have associated the NLvariable y with the model mod. Then suppose I change my mind and want to disassociate the variable y from mod. Is there something like unset?

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## [Primary key in DataFrame](https://discourse.julialang.org/t/primary-key-in-dataframe/60879)

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**Author:** [@Mastomaki](https://discourse.julialang.org/u/Mastomaki)\
**Replies:** 2\
**Last updated:** [May 10, 2021, 10:55pm UTC](https://discourse.julialang.org/t/primary-key-in-dataframe/60879 "2021-05-10T22:55:42Z")

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I use DataFrame to hold data where a set of columns is considered the primary key. So only one record should be present for each primary key. But I suppose in DataFrame such condition cannot be enforced. So for example t…

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## [IOBuffer a Matrix?](https://discourse.julialang.org/t/iobuffer-a-matrix/60913)

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**Author:** [@marianoarnaiz](https://discourse.julialang.org/u/marianoarnaiz)\
**Replies:** 1\
**Last updated:** [May 10, 2021, 10:57pm UTC](https://discourse.julialang.org/t/iobuffer-a-matrix/60913 "2021-05-10T22:57:09Z")

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Hi All! I am making a pseudo wrapper for a Fortran code. I just need to parse a matrix as an input to it. In the terminal i can do: cat data | ./Perplex\_LitMod\_T Where data looks like this: 3 0 0 0 1500 6…

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## [DataFrames output is Latex when using in a notebook](https://discourse.julialang.org/t/dataframes-output-is-latex-when-using-in-a-notebook/60900)

<div class="topic-metadata">

**Author:** [@affans](https://discourse.julialang.org/u/affans)\
**Replies:** 4\
**Last updated:** [May 10, 2021, 9:59pm UTC](https://discourse.julialang.org/t/dataframes-output-is-latex-when-using-in-a-notebook/60900 "2021-05-10T21:59:49Z")

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Running a notebook within VSCode and seeing some problems with DataFrames. Might be a quick PR to detect the display? I am not entirely sure how the display stack works. Happy to help debug with someone.

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