# Latest

**URL:** https://discourse.julialang.org/latest.md?page=735

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

**Page:** 736

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## [Polar plot with 0° at the nadir?](https://discourse.julialang.org/t/polar-plot-with-0-at-the-nadir/92119)

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**Author:** [@rmfritz](https://discourse.julialang.org/u/rmfritz)\
**Replies:** 11\
**Last updated:** [April 3, 2023, 5:54pm UTC](https://discourse.julialang.org/t/polar-plot-with-0-at-the-nadir/92119 "2023-04-03T17:54:59Z")

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Is there any simple way to do this? The default is 0° on the right.

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## [Set "0 degree" location in Polar plot?](https://discourse.julialang.org/t/set-0-degree-location-in-polar-plot/96947)

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**Author:** [@Ahmed\_Salih](https://discourse.julialang.org/u/Ahmed_Salih)\
**Replies:** 2\
**Last updated:** [April 3, 2023, 5:54pm UTC](https://discourse.julialang.org/t/set-0-degree-location-in-polar-plot/96947 "2023-04-03T17:54:16Z")

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Hello! In Matlab one can very easily do: Which basically rotates your plot, so that in this case the Theta Zero Location is at the top. How would I do the same thing in Julia? Kind regards

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## [How to read Parquet files using Parquet2 in a multi-folder structure?](https://discourse.julialang.org/t/how-to-read-parquet-files-using-parquet2-in-a-multi-folder-structure/96957)

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**Author:** [@Ahmed\_Salih](https://discourse.julialang.org/u/Ahmed_Salih)\
**Replies:** 1\
**Last updated:** [April 3, 2023, 5:53pm UTC](https://discourse.julialang.org/t/how-to-read-parquet-files-using-parquet2-in-a-multi-folder-structure/96957 "2023-04-03T17:53:19Z")

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Hello! Suppose I have a folder structure given as: TopFolder A B C Where parquet files are stored inside of A,B and C. I know that if I do: Parquet2.Dataset("TopFolder") Then it will have access to all the parque…

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## [Graph.jl error in a\_star() function](https://discourse.julialang.org/t/graph-jl-error-in-a-star-function/96455)

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**Author:** [@raman\_kumar](https://discourse.julialang.org/u/raman_kumar)\
**Replies:** 15\
**Last updated:** [April 3, 2023, 4:47pm UTC](https://discourse.julialang.org/t/graph-jl-error-in-a-star-function/96455 "2023-04-03T16:47:04Z")

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I want to get shortest distance between two edges. using Graphs,GraphRecipes ,Plots,Karnak,NetworkLayout,Colors,SimpleWeightedGraphs begin G=SimpleWeightedGraph(5) add\_edge!(G, 1, 2,2000) add\_edge!(G, 1, 3,180…

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## [How to find Jacobian Matrix, df/du, df/dt, directional derivatives, etc. in julia](https://discourse.julialang.org/t/how-to-find-jacobian-matrix-df-du-df-dt-directional-derivatives-etc-in-julia/97016)

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**Author:** [@Hassan\_Alam](https://discourse.julialang.org/u/Hassan_Alam)\
**Replies:** 10\
**Last updated:** [April 3, 2023, 4:41pm UTC](https://discourse.julialang.org/t/how-to-find-jacobian-matrix-df-du-df-dt-directional-derivatives-etc-in-julia/97016 "2023-04-03T16:41:32Z")

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Hello, I have solved a system of ODE equation by using Jacobian Sparsity method. I am reading this link ODE Problems · DifferentialEquations.jl. It says that we can find df/du by using the command jac(J,u,p,t) or J=jac(u…

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## [Calculation of two-time correlation function and spectrum in quantumoptics.jl](https://discourse.julialang.org/t/calculation-of-two-time-correlation-function-and-spectrum-in-quantumoptics-jl/97009)

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**Author:** [@arpan\_chatterjee](https://discourse.julialang.org/u/arpan_chatterjee)\
**Replies:** 0\
**Last updated:** [April 3, 2023, 10:52am UTC](https://discourse.julialang.org/t/calculation-of-two-time-correlation-function-and-spectrum-in-quantumoptics-jl/97009 "2023-04-03T10:52:26Z")

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If I have some time-dependent Hamiltonian whose frequency is time dependent not amplitude as described in the example of the documentation in quantumoptics.jl. Then How can I construct two-time correlation function for s…

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## [Equivalent of BenchmarkTools in Python?](https://discourse.julialang.org/t/equivalent-of-benchmarktools-in-python/97011)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 8\
**Last updated:** [April 3, 2023, 3:09pm UTC](https://discourse.julialang.org/t/equivalent-of-benchmarktools-in-python/97011 "2023-04-03T15:09:42Z")

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Which is the equivalent of @btime/ @benchmark in Python? I would like something to interactively benchmark a single expression (function call) and where the number of run adapt to the running cost of the expression to b…

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## [Weird memory allocation when passing functions as keyword arguments](https://discourse.julialang.org/t/weird-memory-allocation-when-passing-functions-as-keyword-arguments/96920)

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**Author:** [@sunoru](https://discourse.julialang.org/u/sunoru)\
**Replies:** 6\
**Last updated:** [April 3, 2023, 3:01pm UTC](https://discourse.julialang.org/t/weird-memory-allocation-when-passing-functions-as-keyword-arguments/96920 "2023-04-03T15:01:28Z")

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I was trying to understand the cause of some unexpected memory allocations and found the program has the following strange behaviors. I am really confused and hope someone can help me figure it out, thanks! I tested on 1…

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## [Multiple modules in single package](https://discourse.julialang.org/t/multiple-modules-in-single-package/5615)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 15\
**Last updated:** [April 3, 2023, 2:59pm UTC](https://discourse.julialang.org/t/multiple-modules-in-single-package/5615 "2023-04-03T14:59:21Z")

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I found that a rather short function I use in the unit tests of a package would be useful somewhere else. If I don’t want to make a separate package for it, is it possible to put it in a separate module in the same packa…

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## [O2 versus O3](https://discourse.julialang.org/t/o2-versus-o3/97015)

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**Author:** [@Benq](https://discourse.julialang.org/u/Benq)\
**Replies:** 0\
**Last updated:** [April 3, 2023, 2:43pm UTC](https://discourse.julialang.org/t/o2-versus-o3/97015 "2023-04-03T14:43:12Z")

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I was reading through Performance Tips · The Julia Language and I noticed that the -O flag was not mentioned. Can the -O flag be used to speed up the examples in this section? If not, what’s a simple example where the -O …

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## [Permutedims not working correctly with NamedArray where names are symbols](https://discourse.julialang.org/t/permutedims-not-working-correctly-with-namedarray-where-names-are-symbols/97014)

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**Author:** [@Mitch\_Phillipson](https://discourse.julialang.org/u/Mitch_Phillipson)\
**Replies:** 1\
**Last updated:** [April 3, 2023, 2:39pm UTC](https://discourse.julialang.org/t/permutedims-not-working-correctly-with-namedarray-where-names-are-symbols/97014 "2023-04-03T14:39:35Z")

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I’m trying to permute the dimensions of a NamedArray where the names are symbols. However, I’m getting “Method Error: Cannot convert an object of type String to an object of type Symbol” Here is an example of the code I…

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## [Converting nested vectors of Any](https://discourse.julialang.org/t/converting-nested-vectors-of-any/97012)

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**Author:** [@kingoslo](https://discourse.julialang.org/u/kingoslo)\
**Replies:** 1\
**Last updated:** [April 3, 2023, 2:06pm UTC](https://discourse.julialang.org/t/converting-nested-vectors-of-any/97012 "2023-04-03T14:06:35Z")

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Hello there, I have parsed json from a file. According to the language that made the data, it contains a “collection” of matrices of 64-bit floats. But it is being read in as a format involving Any: julia\> raw = JSON.p…

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## ["Packaging" dependencies into a sysimage](https://discourse.julialang.org/t/packaging-dependencies-into-a-sysimage/96548)

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**Author:** [@sstroemer](https://discourse.julialang.org/u/sstroemer)\
**Replies:** 4\
**Last updated:** [April 3, 2023, 1:29pm UTC](https://discourse.julialang.org/t/packaging-dependencies-into-a-sysimage/96548 "2023-04-03T13:29:50Z")

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Based on the tutorial of PackageCompiler.jl, I am using the following to create a sysimage: julia --project=. \_create\_sysimage.jl. That file contains: \_create\_sysimage.jl: import Pkg Pkg.add("PackageCompiler") Pkg.add(…

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## [Job shop scheduling](https://discourse.julialang.org/t/job-shop-scheduling/96938)

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**Author:** [@baprata](https://discourse.julialang.org/u/baprata)\
**Replies:** 4\
**Last updated:** [April 3, 2023, 12:52pm UTC](https://discourse.julialang.org/t/job-shop-scheduling/96938 "2023-04-03T12:52:40Z")

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I am studying the mixed-integer linear programming formulation for the job shop with makespan minimization proposed by Manne (see Equations (1)-(7) from Ku and Beck (2016) http://dx.doi.org/10.1016/j.cor.2016.04.006, and…

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## [XLSX.DataTable error](https://discourse.julialang.org/t/xlsx-datatable-error/96993)

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**Author:** [@Leon6](https://discourse.julialang.org/u/Leon6)\
**Replies:** 3\
**Last updated:** [April 3, 2023, 12:17pm UTC](https://discourse.julialang.org/t/xlsx-datatable-error/96993 "2023-04-03T12:17:33Z")

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My script was running OK while on Julia V1.7. I recently upgraded my Julia to V1.8.5, now I have trouble reading info out of xlsx files. Would anyone please help me out? Here are the errors: ERROR: LoadError: MethodErr…

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## [How do I incorporate a boundary function for a vector in another function](https://discourse.julialang.org/t/how-do-i-incorporate-a-boundary-function-for-a-vector-in-another-function/97005)

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**Author:** [@alekee](https://discourse.julialang.org/u/alekee)\
**Replies:** 3\
**Last updated:** [April 3, 2023, 10:33am UTC](https://discourse.julialang.org/t/how-do-i-incorporate-a-boundary-function-for-a-vector-in-another-function/97005 "2023-04-03T10:33:56Z")

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Y’all gonna see a lot from me cuz i dunno what the fuck i’m doing :). Working on problem set 2 of the MIT course and i’ve hit a wall. The question is: Write a function box\_blur(v, l) that blurs a vector v with a window …

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## [LSP not showing error](https://discourse.julialang.org/t/lsp-not-showing-error/96726)

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**Author:** [@jdev22](https://discourse.julialang.org/u/jdev22)\
**Replies:** 5\
**Last updated:** [April 3, 2023, 10:02am UTC](https://discourse.julialang.org/t/lsp-not-showing-error/96726 "2023-04-03T10:02:05Z")

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I’m new to Julia development and was just trying out the following snippet: \` function foo()::String return 22 end \` I expected LSP to have highlighted the code with error, because the return type of this function …

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## [Save @btime output](https://discourse.julialang.org/t/save-btime-output/53595)

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**Author:** [@mkarikom](https://discourse.julialang.org/u/mkarikom)\
**Replies:** 7\
**Last updated:** [April 1, 2023, 9:52am UTC](https://discourse.julialang.org/t/save-btime-output/53595 "2023-04-01T09:52:57Z")

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Is there a simple way to do this? I just want to save the time n in milliseconds e.g. n = @btime foo for some benchmark like: check = nothing function checkaaa() rand(10) \* rand(10)' return nothing end check …

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## [Argument type of higher order functions](https://discourse.julialang.org/t/argument-type-of-higher-order-functions/96989)

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**Author:** [@empet](https://discourse.julialang.org/u/empet)\
**Replies:** 4\
**Last updated:** [April 3, 2023, 8:21am UTC](https://discourse.julialang.org/t/argument-type-of-higher-order-functions/96989 "2023-04-03T08:21:17Z")

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If I define: function myfunc(f::T, g::T; b=2.5 ) where T\<:Function #some lines here h(t) = b\*(f(t) +g(t)^2) end f(t; a=2)=a\*t g(t; a=3)=a+exp(t) h=myfunc(f, g) h(1.3) it is thrown the error: MethodError: no me…

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## [Anyone else having issues with 'nightly'?](https://discourse.julialang.org/t/anyone-else-having-issues-with-nightly/96891)

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**Author:** [@pat-alt](https://discourse.julialang.org/u/pat-alt)\
**Replies:** 3\
**Last updated:** [April 3, 2023, 6:57am UTC](https://discourse.julialang.org/t/anyone-else-having-issues-with-nightly/96891 "2023-04-03T06:57:22Z")

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My workflows for Julia ‘nightly’ have started failing a few days ago: see here, here and here. From the error messages it looks like several deps have failed to compile, but can’t really make sense of why. Am I doing so…

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## [Suggestions needed: diagonalizing large Hermitian sparse matrix](https://discourse.julialang.org/t/suggestions-needed-diagonalizing-large-hermitian-sparse-matrix/96580)

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**Author:** [@Chong\_Wang](https://discourse.julialang.org/u/Chong_Wang)\
**Replies:** 4\
**Last updated:** [April 3, 2023, 6:03am UTC](https://discourse.julialang.org/t/suggestions-needed-diagonalizing-large-hermitian-sparse-matrix/96580 "2023-04-03T06:03:37Z")

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I need to find a few eigenvalues and eigenvectors of some large Hermitian sparse matrices. Right now, I am trying Arpack.jl and KrylovKit.jl. Here are some considerations and my experiences. Arpack.jl does not have sp…

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## [Eigenvalues without sorting LinearAlgrebra.jl](https://discourse.julialang.org/t/eigenvalues-without-sorting-linearalgrebra-jl/96997)

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**Author:** [@Sergey\_Novak](https://discourse.julialang.org/u/Sergey_Novak)\
**Replies:** 6\
**Last updated:** [April 3, 2023, 5:37am UTC](https://discourse.julialang.org/t/eigenvalues-without-sorting-linearalgrebra-jl/96997 "2023-04-03T05:37:41Z")

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Hello! I calculate the equilibrium points for a continuous dynamical system and then calculate it eigenvalues. I don’t need to sort these eigenvalues, otherwise I’ll have to literally search through all the phase variab…

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## [Wrong dispatch due to kwargs?](https://discourse.julialang.org/t/wrong-dispatch-due-to-kwargs/96977)

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**Author:** [@freeman](https://discourse.julialang.org/u/freeman)\
**Replies:** 6\
**Last updated:** [April 3, 2023, 5:28am UTC](https://discourse.julialang.org/t/wrong-dispatch-due-to-kwargs/96977 "2023-04-03T05:28:38Z")

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It seems to me that the dispatch system is doing something wrong. Apologies ahead of time if there’s something blindingly obvious that I’m missing here. See the examples below: This is as expected: function func( …

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## [Using a C++ project in Julia which depends on external libraries](https://discourse.julialang.org/t/using-a-c-project-in-julia-which-depends-on-external-libraries/96995)

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**Author:** [@Zachary\_Landry](https://discourse.julialang.org/u/Zachary_Landry)\
**Replies:** 0\
**Last updated:** [April 3, 2023, 3:13am UTC](https://discourse.julialang.org/t/using-a-c-project-in-julia-which-depends-on-external-libraries/96995 "2023-04-03T03:13:45Z")

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I am attempting to allow Julia to use a C++ 3D modeling utility. I have seen examples of running C++ code in Julia using CxxWrap, CxxInterface, etc. but the project I am trying to use depends on an external library (Open…

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## [Which JuMP supported solvers work well on Apple M2?](https://discourse.julialang.org/t/which-jump-supported-solvers-work-well-on-apple-m2/96992)

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**Author:** [@nlaws](https://discourse.julialang.org/u/nlaws)\
**Replies:** 3\
**Last updated:** [April 3, 2023, 3:03am UTC](https://discourse.julialang.org/t/which-jump-supported-solvers-work-well-on-apple-m2/96992 "2023-04-03T03:03:29Z")

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Looking at a new laptop RN and found this interesting discussion regarding Operations Research on M1: There is also this discussion on this discourse regarding CPLEX.jl on M2: However, the first discussion was last u…

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## [How to import a certain module from a package](https://discourse.julialang.org/t/how-to-import-a-certain-module-from-a-package/96963)

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**Author:** [@dmtrung14](https://discourse.julialang.org/u/dmtrung14)\
**Replies:** 5\
**Last updated:** [April 2, 2023, 10:23pm UTC](https://discourse.julialang.org/t/how-to-import-a-certain-module-from-a-package/96963 "2023-04-02T22:23:48Z")

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I was trying to import a module from a package to illustrate, using package.ABC: submodule1, submodule2, ... But then when I applied tests to it, it returns: UndefVarError: ABC not defined. How do I go about resolvi…

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## [Replace symbols within an expression](https://discourse.julialang.org/t/replace-symbols-within-an-expression/96966)

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**Author:** [@weymouth](https://discourse.julialang.org/u/weymouth)\
**Replies:** 3\
**Last updated:** [April 2, 2023, 9:48pm UTC](https://discourse.julialang.org/t/replace-symbols-within-an-expression/96966 "2023-04-02T21:48:53Z")

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I want to take an expression like :(structOne.a\[I\] = tanh(structTwo.b\[I\])) and replace all the composite values with other variables so I can make a function like function f(I,a\_new,b\_new) # can't use composite values…

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## [ChatGPT Plugins, using Julia!](https://discourse.julialang.org/t/chatgpt-plugins-using-julia/96982)

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**Author:** [@logankilpatrick](https://discourse.julialang.org/u/logankilpatrick)\
**Replies:** 3\
**Last updated:** [April 2, 2023, 9:20pm UTC](https://discourse.julialang.org/t/chatgpt-plugins-using-julia/96982 "2023-04-02T21:20:09Z")

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Hey folks, I have spent the last few hours trying to set up some test ChatGPT plugins using Julia, here’s what I ended up with: ChatGPT-Plugins-Collection/julia at main · logankilpatrick/ChatGPT-Plugins-Collection · GitH…

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## [Struggling to understand how NLsolve works](https://discourse.julialang.org/t/struggling-to-understand-how-nlsolve-works/96984)

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**Author:** [@Cam\_Healy](https://discourse.julialang.org/u/Cam_Healy)\
**Replies:** 2\
**Last updated:** [April 2, 2023, 9:08pm UTC](https://discourse.julialang.org/t/struggling-to-understand-how-nlsolve-works/96984 "2023-04-02T21:08:03Z")

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Real stupid question here, but I’m trying to get this simple system of equations to solve using NLsolve. I know this is simple enough that I don’t need a nonlinear solver, but I’m just using this for the time being so I …

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## [Special sessions on Numerical Linear Algebra and Optimization with Julia at Montréal Optimization Days 23](https://discourse.julialang.org/t/special-sessions-on-numerical-linear-algebra-and-optimization-with-julia-at-montreal-optimization-days-23/96986)

<div class="topic-metadata">

**Author:** [@tmigot](https://discourse.julialang.org/u/tmigot)\
**Replies:** 0\
**Last updated:** [April 2, 2023, 8:56pm UTC](https://discourse.julialang.org/t/special-sessions-on-numerical-linear-algebra-and-optimization-with-julia-at-montreal-optimization-days-23/96986 "2023-04-02T20:56:43Z")

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Dear Julia community, The conference Optimization Days will be held at HEC Montreal from May 29th to May 31st, 2023. The conference is in-person only. https://symposia.cirrelt.ca/CORS-JOPT/en/home To make this event a…

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