# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1198

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

**Page:** 1199

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## [DataFrame Matrix Constructor without Copying](https://discourse.julialang.org/t/dataframe-matrix-constructor-without-copying/71916)

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**Author:** [@bmit](https://discourse.julialang.org/u/bmit)\
**Replies:** 7\
**Last updated:** [November 23, 2021, 6:21pm UTC](https://discourse.julialang.org/t/dataframe-matrix-constructor-without-copying/71916 "2021-11-23T18:21:45Z")

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I’m curious why the following method for creating a DataFrame using an existing matrix doesn’t exist. In some ways it seems like the simplest way to create a DataFrame. using DataFrames mat = rand(10000,3) df = DataFram…

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## [ParallelStencil for Vector Fields](https://discourse.julialang.org/t/parallelstencil-for-vector-fields/70997)

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**Author:** [@gerhardu](https://discourse.julialang.org/u/gerhardu)\
**Replies:** 5\
**Last updated:** [November 23, 2021, 6:04pm UTC](https://discourse.julialang.org/t/parallelstencil-for-vector-fields/70997 "2021-11-23T18:04:11Z")

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Hello, I am trying to use ParallelStencil to solve a diffeq on a lattice, where at each lattice site I have an Array (StaticArray) instead of a float. E.g A vector field on a 3D domain. But @init\_parallel\_stencil works…

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## [Dramatic performance change by adding additional unused method](https://discourse.julialang.org/t/dramatic-performance-change-by-adding-additional-unused-method/71771)

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**Author:** [@peremato](https://discourse.julialang.org/u/peremato)\
**Replies:** 33\
**Last updated:** [November 23, 2021, 5:21pm UTC](https://discourse.julialang.org/t/dramatic-performance-change-by-adding-additional-unused-method/71771 "2021-11-23T17:21:22Z")

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This is a followup of not-understanding-linear-growing-allocations. It took me a while to get a manageable reproducer after my first attempt of forgetting a simple const in a type alias. The code is as follows: using Be…

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## [Question for CS types here](https://discourse.julialang.org/t/question-for-cs-types-here/71950)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 1\
**Last updated:** [November 23, 2021, 3:42pm UTC](https://discourse.julialang.org/t/question-for-cs-types-here/71950 "2021-11-23T15:42:03Z")

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To what extent can Julia be labeled “JIT”? It seems to me that the designation JAoT (just ahead of time) is more appropriate, but I’d like to hear other opinions, if there are such. Many thanks!

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## [DataFrame groups as an argument of a function](https://discourse.julialang.org/t/dataframe-groups-as-an-argument-of-a-function/65371)

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**Author:** [@bojusemo](https://discourse.julialang.org/u/bojusemo)\
**Replies:** 15\
**Last updated:** [November 23, 2021, 3:18pm UTC](https://discourse.julialang.org/t/dataframe-groups-as-an-argument-of-a-function/65371 "2021-11-23T15:18:35Z")

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Hi Guys, May you help me, please? How can I use the groups obtained from a DataFrame with the Split-Apply-Combine Strategy as an argument for a function into another function? I have try to do it by three ways but it d…

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## [PackageCompiler: Setting the number of threads](https://discourse.julialang.org/t/packagecompiler-setting-the-number-of-threads/31611)

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**Author:** [@scj](https://discourse.julialang.org/u/scj)\
**Replies:** 5\
**Last updated:** [November 23, 2021, 3:14pm UTC](https://discourse.julialang.org/t/packagecompiler-setting-the-number-of-threads/31611 "2021-11-23T15:14:29Z")

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Is it possible to set the number of Julia threads when building an executable using PackageCompiler? module Hello Base.@ccallable function julia\_main(ARGS::Vector{String})::Cint println(Threads.nthreads()) retur…

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## [JuliaHPC Meeting](https://discourse.julialang.org/t/juliahpc-meeting/49093)

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**Author:** [@simonbyrne](https://discourse.julialang.org/u/simonbyrne)\
**Replies:** 10\
**Last updated:** [November 23, 2021, 3:07pm UTC](https://discourse.julialang.org/t/juliahpc-meeting/49093 "2021-11-23T15:07:11Z")

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Several of us have started a roughly-monthly Julia on HPC-related discussion. The next one is to be held tomorrow (for me at least, probably today for almost everyone else): 18:00 UTC (2pm US Eastern), Tuesday October 2…

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## [Xticks spacing changes when decorations are hidden](https://discourse.julialang.org/t/xticks-spacing-changes-when-decorations-are-hidden/71937)

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**Author:** [@HenriDeh](https://discourse.julialang.org/u/HenriDeh)\
**Replies:** 2\
**Last updated:** [November 23, 2021, 2:57pm UTC](https://discourse.julialang.org/t/xticks-spacing-changes-when-decorations-are-hidden/71937 "2021-11-23T14:57:50Z")

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Helloo, I made a MWE that emulates the kind of problem I have: begin f = Figure() gl = GridLayout() f.layout\[1,1\] = gl for i in 1:2, j in 1:2 gl\[i,j\] = a = Axis(f) for (i,data…

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## [Msh file to .json](https://discourse.julialang.org/t/msh-file-to-json/71942)

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**Author:** [@Aiswarya](https://discourse.julialang.org/u/Aiswarya)\
**Replies:** 1\
**Last updated:** [November 23, 2021, 2:43pm UTC](https://discourse.julialang.org/t/msh-file-to-json/71942 "2021-11-23T14:43:59Z")

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How can I convert msh file I created in GMSH software to .json data file in Julia. I was using Gridap package. I read there is some way using GridapGmsh but I didn#t see it.

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## [Flux/Zygote: Gradient with respect to inputs and implicit parameters (in 2021)](https://discourse.julialang.org/t/flux-zygote-gradient-with-respect-to-inputs-and-implicit-parameters-in-2021/71931)

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**Author:** [@manuelbb-upb](https://discourse.julialang.org/u/manuelbb-upb)\
**Replies:** 1\
**Last updated:** [November 23, 2021, 12:28pm UTC](https://discourse.julialang.org/t/flux-zygote-gradient-with-respect-to-inputs-and-implicit-parameters-in-2021/71931 "2021-11-23T12:28:14Z")

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Hello all, I have struggled a bit to get the gradient(s) of a loss with a Zygote model both with respect to the model parameters and to the model input. Is it even sensible to do this in one pass? Consider this simple…

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## [Exist a type tree of all types?](https://discourse.julialang.org/t/exist-a-type-tree-of-all-types/71913)

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**Author:** [@MeteorBizone](https://discourse.julialang.org/u/MeteorBizone)\
**Replies:** 5\
**Last updated:** [November 23, 2021, 11:26am UTC](https://discourse.julialang.org/t/exist-a-type-tree-of-all-types/71913 "2021-11-23T11:26:40Z")

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Hello, I’am new. Exist a picture with a type tree of all Julia types?

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## [Ubuntu Julia 1.6.4, juypter notebook not connecting?](https://discourse.julialang.org/t/ubuntu-julia-1-6-4-juypter-notebook-not-connecting/71933)

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**Author:** [@jamaas](https://discourse.julialang.org/u/jamaas)\
**Replies:** 3\
**Last updated:** [November 23, 2021, 11:23am UTC](https://discourse.julialang.org/t/ubuntu-julia-1-6-4-juypter-notebook-not-connecting/71933 "2021-11-23T11:23:00Z")

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I’ve just updated to the latest version of julia, 1.6.4 or ubuntu 20.04, however this has been an ongoing problem with previous julia versions. I can not get the julia kernel to show up in jupyter notebooks. Jupyter is…

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## [Conda.search](https://discourse.julialang.org/t/conda-search/71936)

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**Author:** [@ellocco](https://discourse.julialang.org/u/ellocco)\
**Replies:** 0\
**Last updated:** [November 23, 2021, 10:53am UTC](https://discourse.julialang.org/t/conda-search/71936 "2021-11-23T10:53:41Z")

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Sorry I do not know how to remove this post, it is a known issue in “Conda.jl” /Conda.jl/issues/118 I am struggling with the Conda method “search”, is it a bug or do I missunderstand something, why is following throwin…

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## [How to build functions that work efficiently with arguments of different types?](https://discourse.julialang.org/t/how-to-build-functions-that-work-efficiently-with-arguments-of-different-types/71504)

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**Author:** [@MichaelGao](https://discourse.julialang.org/u/MichaelGao)\
**Replies:** 15\
**Last updated:** [November 23, 2021, 9:57am UTC](https://discourse.julialang.org/t/how-to-build-functions-that-work-efficiently-with-arguments-of-different-types/71504 "2021-11-23T09:57:58Z")

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For implementing sensitivity analysis, I need to build some functions, for example like the one below. function just\_an\_example(a, b, C) a::Float64 b::Float64 C::Vector{Float64} return a + b\*C end (…

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## [Project Officer on Bioeconomy, global trade, deforestation and forest degradation @ EU JRC](https://discourse.julialang.org/t/project-officer-on-bioeconomy-global-trade-deforestation-and-forest-degradation-eu-jrc/71904)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 0\
**Last updated:** [November 22, 2021, 4:57pm UTC](https://discourse.julialang.org/t/project-officer-on-bioeconomy-global-trade-deforestation-and-forest-degradation-eu-jrc/71904 "2021-11-22T16:57:03Z")

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A position for a Project Officer to work on Bioeconomy, global trade, deforestation and forest degradation at the EU Commission Joint Research Center of Ispra (north of Milan). 2 years, renewable up to 6 years. Competit…

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## [Minimisation of a Bolza form loss function in DiffEqFlux framework](https://discourse.julialang.org/t/minimisation-of-a-bolza-form-loss-function-in-diffeqflux-framework/71920)

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**Author:** [@nhcho91](https://discourse.julialang.org/u/nhcho91)\
**Replies:** 3\
**Last updated:** [November 23, 2021, 8:07am UTC](https://discourse.julialang.org/t/minimisation-of-a-bolza-form-loss-function-in-diffeqflux-framework/71920 "2021-11-23T08:07:19Z")

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Brief Summary Problem at hand: minimise J \\left( p \\right) = \\phi \\left( x \\left(t\_{f} \\right) \\right) + \\int\_{t\_{0}}^{t\_{f}} L \\left( \\tau, x\\left(\\tau\\right), p \\right) d\\tau + R\\left( p \\right) subject to \\dot{x}…

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## [Is package a library?](https://discourse.julialang.org/t/is-package-a-library/71924)

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**Author:** [@Evian-Zhang](https://discourse.julialang.org/u/Evian-Zhang)\
**Replies:** 7\
**Last updated:** [November 23, 2021, 8:16am UTC](https://discourse.julialang.org/t/is-package-a-library/71924 "2021-11-23T08:16:41Z")

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I am new to Julia, and I wonder what a package is. I am quite familiar with Rust. In Rust, a crate can either be a library or an executable. As far as I read, the examples interpreting what package is are all about libr…

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## [You appear to have run julia under a different \`mpiexec\` than the one used by MPI.jl](https://discourse.julialang.org/t/you-appear-to-have-run-julia-under-a-different-mpiexec-than-the-one-used-by-mpi-jl/51836)

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**Author:** [@Daniel\_Blatter](https://discourse.julialang.org/u/Daniel_Blatter)\
**Replies:** 4\
**Last updated:** [November 22, 2021, 9:53pm UTC](https://discourse.julialang.org/t/you-appear-to-have-run-julia-under-a-different-mpiexec-than-the-one-used-by-mpi-jl/51836 "2021-11-22T21:53:52Z")

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I’m running MacOS 10.15.6 and I use OpenMPI to run Julia programs. It worked fine with Julia 1.1. Then I uninstalled Julia 1.1, installed Julia 1.5.3, added the MPI.jl package, and now I get the following error whenever …

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## [Serial synchronization issue and request for some general advice](https://discourse.julialang.org/t/serial-synchronization-issue-and-request-for-some-general-advice/71921)

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**Author:** [@zchris9](https://discourse.julialang.org/u/zchris9)\
**Replies:** 1\
**Last updated:** [November 23, 2021, 7:44am UTC](https://discourse.julialang.org/t/serial-synchronization-issue-and-request-for-some-general-advice/71921 "2021-11-23T07:44:51Z")

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Dear Julia Community! I am currently working on a university project where data is streamed to a Raspberry Pi 4 and needs to be processed in a soft real-time environment. The projects goal is to provide infrastructure f…

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## [Julia package to calculate coverage and depth from sam/bam files](https://discourse.julialang.org/t/julia-package-to-calculate-coverage-and-depth-from-sam-bam-files/71888)

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**Author:** [@Lamma](https://discourse.julialang.org/u/Lamma)\
**Replies:** 4\
**Last updated:** [November 23, 2021, 7:42am UTC](https://discourse.julialang.org/t/julia-package-to-calculate-coverage-and-depth-from-sam-bam-files/71888 "2021-11-23T07:42:27Z")

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Hi there, I am wanting to generate coverage and depth statistic for some sam/bam files I have and was wondering if Julia has a package that can do this for me?

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## [Unitful - derived unit simplification?](https://discourse.julialang.org/t/unitful-derived-unit-simplification/71186)

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**Author:** [@mde](https://discourse.julialang.org/u/mde)\
**Replies:** 2\
**Last updated:** [November 23, 2021, 7:32am UTC](https://discourse.julialang.org/t/unitful-derived-unit-simplification/71186 "2021-11-23T07:32:38Z")

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I am fairly new to Unitful and am running into an issue when I multiply a derived unit by one of its component units and want the resulting unit to simplify into the other component unit. Example: \> 1u"M" \* 1u"L" 1 L M…

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## [Does overdubbing in generated function inserts inlined code](https://discourse.julialang.org/t/does-overdubbing-in-generated-function-inserts-inlined-code/71868)

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**Author:** [@Tomas\_Pevny](https://discourse.julialang.org/u/Tomas_Pevny)\
**Replies:** 8\
**Last updated:** [November 23, 2021, 4:26am UTC](https://discourse.julialang.org/t/does-overdubbing-in-generated-function-inserts-inlined-code/71868 "2021-11-23T04:26:41Z")

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Dear All, I am trying to understand the role of generated functions in Zygote / Cassette, as want to properly understand “overdubbing design pattern”. I decided to test the idea by writing a profiler, which will log the…

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## [Trouble translating a simple PyMC3 model to Turing](https://discourse.julialang.org/t/trouble-translating-a-simple-pymc3-model-to-turing/71856)

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**Author:** [@dodoplus](https://discourse.julialang.org/u/dodoplus)\
**Replies:** 39\
**Last updated:** [November 23, 2021, 4:23am UTC](https://discourse.julialang.org/t/trouble-translating-a-simple-pymc3-model-to-turing/71856 "2021-11-23T04:23:22Z")

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I’ve been playing around with Turing solving this simple problem from Allen Downey’s Think Bayes: 23 grizzly bears visit a “trap” in the first season. In the 2nd season, there are 19 bears, 4 of which are repeat custome…

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## [Using Vuetify in Pluto.jl](https://discourse.julialang.org/t/using-vuetify-in-pluto-jl/62217)

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**Author:** [@JackC](https://discourse.julialang.org/u/JackC)\
**Replies:** 1\
**Last updated:** [November 23, 2021, 1:56am UTC](https://discourse.julialang.org/t/using-vuetify-in-pluto-jl/62217 "2021-11-23T01:56:49Z")

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I have a small application that I’m writing using Pluto.jl. The general idea behind it is to display a list of sliders (dynamically generated) over a couple tabs that can be used to set the numbers for specific variables…

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## [\[ANN\] ComplexMixtures.jl: A package to study solute-solvent interactions of molecules of complex shape](https://discourse.julialang.org/t/ann-complexmixtures-jl-a-package-to-study-solute-solvent-interactions-of-molecules-of-complex-shape/61103)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 5\
**Last updated:** [November 23, 2021, 1:31am UTC](https://discourse.julialang.org/t/ann-complexmixtures-jl-a-package-to-study-solute-solvent-interactions-of-molecules-of-complex-shape/61103 "2021-11-23T01:31:40Z")

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Dear all. After a little more than a year after I started seriously learning Julia, I finished what will be soon the 1.0 version of the package I proposed myself to implement while learning this great language. It is a …

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## [Anonymous types](https://discourse.julialang.org/t/anonymous-types/71890)

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**Author:** [@whatsthecraic](https://discourse.julialang.org/u/whatsthecraic)\
**Replies:** 10\
**Last updated:** [November 23, 2021, 1:13am UTC](https://discourse.julialang.org/t/anonymous-types/71890 "2021-11-23T01:13:38Z")

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Is it possible to define an instance of an interface? e.g. something like: abstract type Foo; end instanceOfFoo = convert(Foo, (x=1, y=2))

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## [Read optimization model files into Julia](https://discourse.julialang.org/t/read-optimization-model-files-into-julia/71851)

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**Author:** [@ZHEN\_LIN](https://discourse.julialang.org/u/ZHEN_LIN)\
**Replies:** 7\
**Last updated:** [November 23, 2021, 12:23am UTC](https://discourse.julialang.org/t/read-optimization-model-files-into-julia/71851 "2021-11-23T00:23:40Z")

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I would like to read into Julia some optimization models like the one given in the link below http://qplib.zib.de/QPLIB\_0067.html This is a quadratic optimization problem. It looks like it has formats including gms, lp…

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## [Find position on list (fast)](https://discourse.julialang.org/t/find-position-on-list-fast/71911)

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**Author:** [@programista](https://discourse.julialang.org/u/programista)\
**Replies:** 13\
**Last updated:** [November 22, 2021, 11:24pm UTC](https://discourse.julialang.org/t/find-position-on-list-fast/71911 "2021-11-22T23:24:11Z")

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Me vectors are very long and I am looking for efficient way to : If x=\[“a”;“b”;“c”;“d”;“e”\] and y=\[“b”; “a”; “a”; “c”\] How to find , but very fast, position any y on x expected result: 2 1 1 3 Thanks Pauls

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## [PDEsystems has version conflict?](https://discourse.julialang.org/t/pdesystems-has-version-conflict/71871)

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**Author:** [@Goosee](https://discourse.julialang.org/u/Goosee)\
**Replies:** 17\
**Last updated:** [November 22, 2021, 11:04pm UTC](https://discourse.julialang.org/t/pdesystems-has-version-conflict/71871 "2021-11-22T23:04:43Z")

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I am new to Julia. I installed today the latest version of Julia, Atom and Juno and the packages to run the examples on the NeuralPDE.jl website. I cannot run any command from the package ModelingToolkit that uses “PDESy…

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## [Constructing expressions with local macro variables and Symbols](https://discourse.julialang.org/t/constructing-expressions-with-local-macro-variables-and-symbols/71906)

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**Author:** [@filchristou](https://discourse.julialang.org/u/filchristou)\
**Replies:** 11\
**Last updated:** [November 22, 2021, 9:04pm UTC](https://discourse.julialang.org/t/constructing-expressions-with-local-macro-variables-and-symbols/71906 "2021-11-22T21:04:25Z")

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I want to construct an expression inside a macro, given a particular input parameter. The behavior should be like that: julia\> @macroexpand @mymacro mysym\[15\] :(\[\[:mysym\], 15\]) So I tried to write something like that: …

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