# New to Julia

**URL:** https://discourse.julialang.org/c/first-steps/8.md?page=2

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

**Page:** 3

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## [\`using Pycall\` on Google Colab makes Julia runtime crash](https://discourse.julialang.org/t/using-pycall-on-google-colab-makes-julia-runtime-crash/136718)

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**Author:** [@funatsufumiya](https://discourse.julialang.org/u/funatsufumiya)\
**Replies:** 3\
**Last updated:** [April 15, 2026, 4:51am UTC](https://discourse.julialang.org/t/using-pycall-on-google-colab-makes-julia-runtime-crash/136718 "2026-04-15T04:51:22Z")

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I’d like to use PyCall on Google Colab Julia runtime, but not succeeded. import Pkg; Pkg.add("PyCall") works, however, using PyCall would crash. run(which python) shows /usr/local/bin/python, run(which pip) shows /usr/…

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## [Add versus dev and potential confusion](https://discourse.julialang.org/t/add-versus-dev-and-potential-confusion/136712)

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**Author:** [@mahmah](https://discourse.julialang.org/u/mahmah)\
**Replies:** 0\
**Last updated:** [April 14, 2026, 4:27pm UTC](https://discourse.julialang.org/t/add-versus-dev-and-potential-confusion/136712 "2026-04-14T16:27:59Z")

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“Because you’re expected to make changes to code when you use dev , Julia copies packages that you develop for the first time by specifying its name or URL (for example dev MacroTools or dev https://github.com/FluxML/Mac…

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## [Adding N to each box](https://discourse.julialang.org/t/adding-n-to-each-box/136688)

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**Author:** [@mahmah](https://discourse.julialang.org/u/mahmah)\
**Replies:** 8\
**Last updated:** [April 13, 2026, 1:21pm UTC](https://discourse.julialang.org/t/adding-n-to-each-box/136688 "2026-04-13T13:21:54Z")

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I’m trying to see the sample size in each boxplot using AoG. Looking for a robust solution that allows to easily see the number of elements in each box regardless of whether we use faceting, colors, dodge, e.g. Is this a…

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## [CSV.read with two delimiters](https://discourse.julialang.org/t/csv-read-with-two-delimiters/136685)

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**Author:** [@mahmah](https://discourse.julialang.org/u/mahmah)\
**Replies:** 3\
**Last updated:** [April 11, 2026, 11:04pm UTC](https://discourse.julialang.org/t/csv-read-with-two-delimiters/136685 "2026-04-11T23:04:47Z")

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I have data where each row looks like this: 49, 127 97 136; CSV.read nicely imports it to a DataFrame like this: 49 127 97 136; But I don’t want the semicolon. Can this be imported in a better way? Thanks!

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## [A issue to use PythonCall to call a Simple Python File Of WxPython Hello World](https://discourse.julialang.org/t/a-issue-to-use-pythoncall-to-call-a-simple-python-file-of-wxpython-hello-world/136567)

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**Author:** [@aldo](https://discourse.julialang.org/u/aldo)\
**Replies:** 8\
**Last updated:** [April 6, 2026, 1:59am UTC](https://discourse.julialang.org/t/a-issue-to-use-pythoncall-to-call-a-simple-python-file-of-wxpython-hello-world/136567 "2026-04-06T01:59:33Z")

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Hello, I am new to Julia and just start to learn it this week. I got a problem to use PythonCall to call a Simple Python File Of WxPython Hello World. My Julia code and Python code are below. When I ran Julia code the be…

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## [Documenter.jl cumbersome experience](https://discourse.julialang.org/t/documenter-jl-cumbersome-experience/136552)

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**Author:** [@lilachint](https://discourse.julialang.org/u/lilachint)\
**Replies:** 6\
**Last updated:** [April 4, 2026, 1:05pm UTC](https://discourse.julialang.org/t/documenter-jl-cumbersome-experience/136552 "2026-04-04T13:05:25Z")

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Hi! I’m a new user to Julia that wish to develop some packages. However, when it comes to documentation generation, I find it quite cumbersome. To be specific, I’m a lazy-ish person, and would try to generate documentat…

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## [Type stability of sparse solves?](https://discourse.julialang.org/t/type-stability-of-sparse-solves/133235)

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**Author:** [@loisel](https://discourse.julialang.org/u/loisel)\
**Replies:** 8\
**Last updated:** [April 3, 2026, 9:44am UTC](https://discourse.julialang.org/t/type-stability-of-sparse-solves/133235 "2026-04-03T09:44:02Z")

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Hi, If you run the following code: using SparseArrays A = sparse(\[1.0f0 2.0f0; 3.0f0 4.0f0\]) b = Float32\[1, 2\] println(eltype(A \\ b)) it prints Float64, I thought it should’ve produced a vector of Float32. Is this exp…

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## [Human pose estimation?](https://discourse.julialang.org/t/human-pose-estimation/136513)

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**Author:** [@mahmah](https://discourse.julialang.org/u/mahmah)\
**Replies:** 2\
**Last updated:** [April 2, 2026, 9:15pm UTC](https://discourse.julialang.org/t/human-pose-estimation/136513 "2026-04-02T21:15:04Z")

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Is there any package for human pose estimation written in Julia?

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## [Turing Inference with MTK ODEProblem](https://discourse.julialang.org/t/turing-inference-with-mtk-odeproblem/136506)

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**Author:** [@bieniekmat](https://discourse.julialang.org/u/bieniekmat)\
**Replies:** 0\
**Last updated:** [April 1, 2026, 3:08pm UTC](https://discourse.julialang.org/t/turing-inference-with-mtk-odeproblem/136506 "2026-04-01T15:08:43Z")

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Hi, I am using Turing inference which draws uncertain parameters and then passes them on to the simulate kernel function. The kernel takes a pre-crated ODEProblem and applies the new parameters. The code works but is rea…

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## [Improving the speed for the forward solve of a Universal Differential Equation (UDE)](https://discourse.julialang.org/t/improving-the-speed-for-the-forward-solve-of-a-universal-differential-equation-ude/130583)

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**Author:** [@Ashima\_Kalathingal](https://discourse.julialang.org/u/Ashima_Kalathingal)\
**Replies:** 21\
**Last updated:** [March 30, 2026, 5:24pm UTC](https://discourse.julialang.org/t/improving-the-speed-for-the-forward-solve-of-a-universal-differential-equation-ude/130583 "2026-03-30T17:24:00Z")

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Hello everyone, I have a UDE here, and I am trying to improve its speed during the forward solve so that the optimization is also faster. Right now optimization part is very slow. Here is a working code you can try out …

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## [ERROR: Debugger.jl requires a LineEditREPL type of REPL](https://discourse.julialang.org/t/error-debugger-jl-requires-a-lineeditrepl-type-of-repl/128760)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 18\
**Last updated:** [March 27, 2026, 8:38pm UTC](https://discourse.julialang.org/t/error-debugger-jl-requires-a-lineeditrepl-type-of-repl/128760 "2026-03-27T20:38:59Z")

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PS K:\\uc24\> julia \_ \_ \_ \_(\_)\_ | Documentation: https://docs.julialang.org (\_) | (\_) (\_) | \_ \_ \_| |\_ \_\_ \_ | Type "?" for help, "\]?" for Pkg help. | | | | | | |/ \_\` | | |…

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## [Avoiding deepcopy() with functions using union of types as input](https://discourse.julialang.org/t/avoiding-deepcopy-with-functions-using-union-of-types-as-input/136337)

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**Author:** [@mahmah](https://discourse.julialang.org/u/mahmah)\
**Replies:** 10\
**Last updated:** [March 24, 2026, 2:17pm UTC](https://discourse.julialang.org/t/avoiding-deepcopy-with-functions-using-union-of-types-as-input/136337 "2026-03-24T14:17:04Z")

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Hi, I have two custom defined types that I use in my functions, i.e. m::Union{T1,T2}. T1 and T2 have some overlaps with respect to field names and number of fields. I want my functions to deliver a new version of etiher…

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## [Julia debugging is extremely slow](https://discourse.julialang.org/t/julia-debugging-is-extremely-slow/135839)

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**Author:** [@tue](https://discourse.julialang.org/u/tue)\
**Replies:** 102\
**Last updated:** [March 24, 2026, 9:07am UTC](https://discourse.julialang.org/t/julia-debugging-is-extremely-slow/135839 "2026-03-24T09:07:16Z")

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I was programming quite a bit in julia about 5-6 years ago but ended up quitting since the debugger was just too unuseable. Now I’m testing it out again for a small side project and I once again find myself with the same…

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## [\[BoundaryValueDiffEq.jl\] Reducing allocations](https://discourse.julialang.org/t/boundaryvaluediffeq-jl-reducing-allocations/136255)

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**Author:** [@MaxSchelski](https://discourse.julialang.org/u/MaxSchelski)\
**Replies:** 9\
**Last updated:** [March 23, 2026, 2:48pm UTC](https://discourse.julialang.org/t/boundaryvaluediffeq-jl-reducing-allocations/136255 "2026-03-23T14:48:23Z")

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Hi, I started to implement my Python pipeline for solving boundary value problems in Julia using BoundaryValueDiffEq.jl. I tried to optimize the functions but I am wondering if it is possible to increase performance fur…

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## [Precompilation error for DynamicGrids](https://discourse.julialang.org/t/precompilation-error-for-dynamicgrids/136187)

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**Author:** [@gannd](https://discourse.julialang.org/u/gannd)\
**Replies:** 3\
**Last updated:** [March 14, 2026, 8:52pm UTC](https://discourse.julialang.org/t/precompilation-error-for-dynamicgrids/136187 "2026-03-14T20:52:20Z")

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I am interested in using DynamicGrids.jl but ran into the following precompilation errors during installation: ? ConstructionBaseExtras ✗ DimensionalData ? ModelParameters ✗ DynamicGrids Precompiling packages finish…

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## [VSCode formatter not working](https://discourse.julialang.org/t/vscode-formatter-not-working/136182)

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**Author:** [@acgc99](https://discourse.julialang.org/u/acgc99)\
**Replies:** 4\
**Last updated:** [March 13, 2026, 12:39pm UTC](https://discourse.julialang.org/t/vscode-formatter-not-working/136182 "2026-03-13T12:39:40Z")

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I made this function with a long signature: function foo(Aₙₘ::AbstractMatrix{Float64}, Eₙₘ::AbstractMatrix{Float64}, JAₙₘ::AbstractMatrix{Float64}, JEₙₘ::AbstractMatrix{Float64}, mn::Int, dn::Int, Cₙ::AbstractVector{Flo…

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## [Programmatically create formula](https://discourse.julialang.org/t/programmatically-create-formula/136170)

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**Author:** [@mahmah](https://discourse.julialang.org/u/mahmah)\
**Replies:** 4\
**Last updated:** [March 12, 2026, 7:27pm UTC](https://discourse.julialang.org/t/programmatically-create-formula/136170 "2026-03-12T19:27:52Z")

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Hi, I’m wanting to use this formula programatically: f = @formula(var ~ A \* B + (1 | id)) Here’s what the AI recommends, but it doesn’t seem to work: varname = :y # or Symbol("y") f = @formula($(varname) ~ A \* B + (…

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## [Error in defining the function](https://discourse.julialang.org/t/error-in-defining-the-function/58540)

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**Author:** [@Manisha\_07](https://discourse.julialang.org/u/Manisha_07)\
**Replies:** 2\
**Last updated:** [March 11, 2026, 12:57pm UTC](https://discourse.julialang.org/t/error-in-defining-the-function/58540 "2026-03-11T12:57:29Z")

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Hello When I am trying to define the function and execute, I am getting the following error. Please help me in solving this " cannot define function f; it already has a value Stacktrace: \[1\] top-level scope @ none:…

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## [MLJ/MljFlux standardisation of variables in each cross-validation fold](https://discourse.julialang.org/t/mlj-mljflux-standardisation-of-variables-in-each-cross-validation-fold/136093)

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**Author:** [@Pablo\_G-D](https://discourse.julialang.org/u/Pablo_G-D)\
**Replies:** 4\
**Last updated:** [March 10, 2026, 3:54pm UTC](https://discourse.julialang.org/t/mlj-mljflux-standardisation-of-variables-in-each-cross-validation-fold/136093 "2026-03-10T15:54:57Z")

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Hi all, I am learning Julia, and so far I have implemented a few Bayesian models using Turing and other packages. I found it quite fast and reliable. I am now building a neural network model for a land-use/land-cover t…

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## [This Julia process exited with code 9. Press any key to close the terminal](https://discourse.julialang.org/t/this-julia-process-exited-with-code-9-press-any-key-to-close-the-terminal/136098)

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**Author:** [@mekapses](https://discourse.julialang.org/u/mekapses)\
**Replies:** 3\
**Last updated:** [March 9, 2026, 11:21am UTC](https://discourse.julialang.org/t/this-julia-process-exited-with-code-9-press-any-key-to-close-the-terminal/136098 "2026-03-09T11:21:24Z")

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I’m running code that has two potential problem areas: a large dataframe with images, and an analysis which may create arrays that aren’t gc’d. When I run the code, either in VS Code or the REPL i get the unhelpful messa…

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## [I'm new to Julia and am hoping to use Apple's MLX Framework with Julia](https://discourse.julialang.org/t/im-new-to-julia-and-am-hoping-to-use-apples-mlx-framework-with-julia/136073)

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**Author:** [@Bill\_Oliver](https://discourse.julialang.org/u/Bill_Oliver)\
**Replies:** 12\
**Last updated:** [March 8, 2026, 2:20pm UTC](https://discourse.julialang.org/t/im-new-to-julia-and-am-hoping-to-use-apples-mlx-framework-with-julia/136073 "2026-03-08T14:20:57Z")

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I’m new to Julia and I am loving the language. Some test code I have runs in about 2 minutes, which I found astounding given the amount of computation involved and that the code is written with loops. However, when I por…

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## [Hot reload (development) in Bonito.jl](https://discourse.julialang.org/t/hot-reload-development-in-bonito-jl/136056)

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**Author:** [@miro-ka](https://discourse.julialang.org/u/miro-ka)\
**Replies:** 3\
**Last updated:** [March 7, 2026, 12:04pm UTC](https://discourse.julialang.org/t/hot-reload-development-in-bonito-jl/136056 "2026-03-07T12:04:44Z")

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Please, is there a way to get hot-reload while I work on the app in Bonito.jl? I have tried revise, liveServer, but nothing worked. I want to change some logic, style in the Bonito app and see the changes in browser. Th…

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## [Hello guys! i'm new can pls tell me the things I need to know](https://discourse.julialang.org/t/hello-guys-im-new-can-pls-tell-me-the-things-i-need-to-know/136059)

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**Author:** [@MiniFlux\_YT](https://discourse.julialang.org/u/MiniFlux_YT)\
**Replies:** 6\
**Last updated:** [March 7, 2026, 3:05am UTC](https://discourse.julialang.org/t/hello-guys-im-new-can-pls-tell-me-the-things-i-need-to-know/136059 "2026-03-07T03:05:32Z")

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pls show me around and also I like to interact with people a lot :slight\_smile:

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## [Perplexed by behavior of module scope changing variables](https://discourse.julialang.org/t/perplexed-by-behavior-of-module-scope-changing-variables/136075)

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**Author:** [@Snowy](https://discourse.julialang.org/u/Snowy)\
**Replies:** 2\
**Last updated:** [March 7, 2026, 1:06am UTC](https://discourse.julialang.org/t/perplexed-by-behavior-of-module-scope-changing-variables/136075 "2026-03-07T01:06:08Z")

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Hello, I must be doing something wrong. Can someone explain this behavior to me? module A using DataFrames x = DataFrame(a=\[1,3\],b=\[4,3\]) export x end module B using ..A function add\_stuff(df…

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## [Does Arrow.jl support enums?](https://discourse.julialang.org/t/does-arrow-jl-support-enums/89163)

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**Author:** [@freeman](https://discourse.julialang.org/u/freeman)\
**Replies:** 13\
**Last updated:** [March 5, 2026, 8:23pm UTC](https://discourse.julialang.org/t/does-arrow-jl-support-enums/89163 "2026-03-05T20:23:01Z")

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I’m surprised that the code below doesn’t work. @enum MyEnum LALA1 LALA2 LALA3 x = \[LALA1, LALA1, LALA3, LALA2\] table = (cols1=x,) io = IOBuffer() Arrow.write(io, table) ERROR: MethodError: no method matching arrowtype…

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## [Global const dataframe](https://discourse.julialang.org/t/global-const-dataframe/135996)

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**Author:** [@mekapses](https://discourse.julialang.org/u/mekapses)\
**Replies:** 4\
**Last updated:** [March 4, 2026, 9:20pm UTC](https://discourse.julialang.org/t/global-const-dataframe/135996 "2026-03-04T21:20:35Z")

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I’ve got a module DataManagment with a module global main\_dataframe defined as such: global const main\_dataframe = DataFrame() I’m using it to have a main store of data for a series of experiments. But when I access it…

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## [Symbolics.jl simplify exp(0) to 1](https://discourse.julialang.org/t/symbolics-jl-simplify-exp-0-to-1/135970)

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**Author:** [@jhai](https://discourse.julialang.org/u/jhai)\
**Replies:** 1\
**Last updated:** [March 2, 2026, 6:47pm UTC](https://discourse.julialang.org/t/symbolics-jl-simplify-exp-0-to-1/135970 "2026-03-02T18:47:55Z")

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I’m trying to check a system of linear differential equations using symbolic variables: X'(t)=R(\\alpha)X(t) This is my code using Symbolics using SymbolicUtils using LinearAlgebra @variables α t R = \[cos(α) -sin(α);…

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## [Makie density() and datetime](https://discourse.julialang.org/t/makie-density-and-datetime/135955)

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**Author:** [@mahmah](https://discourse.julialang.org/u/mahmah)\
**Replies:** 1\
**Last updated:** [March 2, 2026, 8:25am UTC](https://discourse.julialang.org/t/makie-density-and-datetime/135955 "2026-03-02T08:25:13Z")

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Is there an easy way to get a density from a DateTime vector in Makie? Thanks!

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## [Problems with julia web page](https://discourse.julialang.org/t/problems-with-julia-web-page/135908)

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**Author:** [@jdukelow](https://discourse.julialang.org/u/jdukelow)\
**Replies:** 6\
**Last updated:** [February 28, 2026, 9:31pm UTC](https://discourse.julialang.org/t/problems-with-julia-web-page/135908 "2026-02-28T21:31:50Z")

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I have been unable to access the julia documentation pdf, have been unable to access juliabox and have been unable to download the julia language tarball. I am dead in the water. What is going on. I am using Mint Linux …

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## [Audio processing in Julia](https://discourse.julialang.org/t/audio-processing-in-julia/35248)

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**Author:** [@minifdez11](https://discourse.julialang.org/u/minifdez11)\
**Replies:** 6\
**Last updated:** [February 27, 2026, 4:55pm UTC](https://discourse.julialang.org/t/audio-processing-in-julia/35248 "2026-02-27T16:55:30Z")

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Hi, I want to make some operations with an mp3 file or WAV file, like splitting, but idk how to make it in Julia, i saw that the pkgs LibSndFile.jl, AudioIO.jl and WAV.jl don’t work well, is there any library that will h…

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