# New to Julia

**URL:** https://discourse.julialang.org/c/first-steps/8.md?page=11

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

**Page:** 12

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## [Receive the success status of \`push!(Set, element)\`](https://discourse.julialang.org/t/receive-the-success-status-of-push-set-element/130988)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 24\
**Last updated:** [July 25, 2025, 8:21am UTC](https://discourse.julialang.org/t/receive-the-success-status-of-push-set-element/130988 "2025-07-25T08:21:15Z")

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I can push! an element to a Set. julia\> S = Set(); julia\> e = 1; julia\> push!(S, e) Set{Any} with 1 element: 1 But I am not aware of a straightforward way to understand if the element e was new to S. Therefore I w…

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## [Crash of eigenvalues calculations with arpack](https://discourse.julialang.org/t/crash-of-eigenvalues-calculations-with-arpack/130983)

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**Author:** [@Choleva](https://discourse.julialang.org/u/Choleva)\
**Replies:** 1\
**Last updated:** [July 23, 2025, 8:07pm UTC](https://discourse.julialang.org/t/crash-of-eigenvalues-calculations-with-arpack/130983 "2025-07-23T20:07:26Z")

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I have a problem of crash of eigenvalues calculations by Arpack.v0.5.4 only if the size of the array becomes very large The bugging line of the program is (line 99) ‘’‘Eigen = eigs(Sierp3, nev=1, which=:LM, sigma=1.7)…

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## [Indexing an array of arbitrary dimension](https://discourse.julialang.org/t/indexing-an-array-of-arbitrary-dimension/130977)

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**Author:** [@prconlin](https://discourse.julialang.org/u/prconlin)\
**Replies:** 4\
**Last updated:** [July 23, 2025, 4:07pm UTC](https://discourse.julialang.org/t/indexing-an-array-of-arbitrary-dimension/130977 "2025-07-23T16:07:59Z")

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I’m trying to write a function which returns a random index for each dimension of an array. It’s easy to do this if the dimensions of the array are known, but I want to abstract my function to work on arrays of arbitrar…

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## [Parametric Structs](https://discourse.julialang.org/t/parametric-structs/130960)

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**Author:** [@lancejnelson](https://discourse.julialang.org/u/lancejnelson)\
**Replies:** 10\
**Last updated:** [July 23, 2025, 2:45pm UTC](https://discourse.julialang.org/t/parametric-structs/130960 "2025-07-23T14:45:01Z")

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From a performance stand point, which is better: struct FlexibleSystem{D, S, TCELL} \<: AbstractSystem{D} particles::AbstractVector{S} cell::TCELL data::Dict{Symbol, Any} # Store arbitrary data about the ato…

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## [How to find which code is generating a warning?](https://discourse.julialang.org/t/how-to-find-which-code-is-generating-a-warning/130541)

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**Author:** [@orebas](https://discourse.julialang.org/u/orebas)\
**Replies:** 10\
**Last updated:** [July 22, 2025, 7:27pm UTC](https://discourse.julialang.org/t/how-to-find-which-code-is-generating-a-warning/130541 "2025-07-22T19:27:16Z")

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Some code in my package is generating the below warning. (Actually I think it’s probably 10-20 places). Presumably this is how I’m supposed to learn that I have to update my code. How do I get a list of the problemati…

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## [Julia vs NumPy broadcasting](https://discourse.julialang.org/t/julia-vs-numpy-broadcasting/130908)

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**Author:** [@Donald](https://discourse.julialang.org/u/Donald)\
**Replies:** 23\
**Last updated:** [July 22, 2025, 2:51pm UTC](https://discourse.julialang.org/t/julia-vs-numpy-broadcasting/130908 "2025-07-22T14:51:54Z")

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I’m trying to compute the step response of a linear system with four degrees of freedom in Julia. This can be done reasonably efficiently in Python using NumPy broadcasting: import numpy as np def step\_analytical(A, B…

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## [Signal Comparison Block](https://discourse.julialang.org/t/signal-comparison-block/130905)

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**Author:** [@madtorresga](https://discourse.julialang.org/u/madtorresga)\
**Replies:** 2\
**Last updated:** [July 21, 2025, 9:20pm UTC](https://discourse.julialang.org/t/signal-comparison-block/130905 "2025-07-21T21:20:04Z")

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Hello, I’m trying to compare 3 signals from the cells array like this: ... @equations begin # Series connect all cells \[connect(cells\[i\].n, cells\[i+1\].p) for i in 1:length(cells)-1\] v\_max ~ ma…

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## [why doesn't \`@.\` always broadcast?](https://discourse.julialang.org/t/why-doesnt-always-broadcast/130892)

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**Author:** [@rokke](https://discourse.julialang.org/u/rokke)\
**Replies:** 12\
**Last updated:** [July 21, 2025, 3:00pm UTC](https://discourse.julialang.org/t/why-doesnt-always-broadcast/130892 "2025-07-21T15:00:06Z")

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some examples: julia\> @. x-\>x\[1\] #1 (generic function with 1 method) julia\> ans( \[\[1,2,3\],\[9,8,7\]\] ) 3-element Vector{Int64}: 1 2 3 julia\> @. x-\>getindex(x,1) #3 (generic function with 1 method) julia\> ans( \[\[1,2,…

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## [Segment fault when calling shared library from node plotting png using CairoMakie library](https://discourse.julialang.org/t/segment-fault-when-calling-shared-library-from-node-plotting-png-using-cairomakie-library/130794)

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**Author:** [@zkbitcoin](https://discourse.julialang.org/u/zkbitcoin)\
**Replies:** 3\
**Last updated:** [July 20, 2025, 4:01pm UTC](https://discourse.julialang.org/t/segment-fault-when-calling-shared-library-from-node-plotting-png-using-cairomakie-library/130794 "2025-07-20T16:01:08Z")

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have simple .jl (below are source files) program flow is: test.js calls c program which calls julia program when using svg extension const result = generate\_c(‘td’, 250, 250, ‘test\_draw.svg’); image is generated w…

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## [Change the axis label](https://discourse.julialang.org/t/change-the-axis-label/130811)

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**Author:** [@Geegee](https://discourse.julialang.org/u/Geegee)\
**Replies:** 2\
**Last updated:** [July 18, 2025, 9:43am UTC](https://discourse.julialang.org/t/change-the-axis-label/130811 "2025-07-18T09:43:35Z")

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I have code like this and I get a figure as expected dfrm\_amp = DataFrame(px\_x= x, px\_y = y, z=amplitude, param\_id="amplitude") dfrm\_freq = DataFrame(px\_x= x, px\_y = y, z=driving\_freqs, param\_id="rabi\_freq") dfrm\_offset…

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## [Write struct into binary file and read it back](https://discourse.julialang.org/t/write-struct-into-binary-file-and-read-it-back/130648)

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**Author:** [@Krisztian\_Novak](https://discourse.julialang.org/u/Krisztian_Novak)\
**Replies:** 15\
**Last updated:** [July 17, 2025, 3:25pm UTC](https://discourse.julialang.org/t/write-struct-into-binary-file-and-read-it-back/130648 "2025-07-17T15:25:42Z")

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I try to write a struct into a binary file and read it back. My code is the following: struct STRUCT x::Float64 y::Float64 z::Float64 end isbitstype(STRUCT) rp = STRUCT(2.0, 3.0, 4.0) open("test.bin", "w…

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## [Is Modal discontinuous galerkin implemented in trixi?](https://discourse.julialang.org/t/is-modal-discontinuous-galerkin-implemented-in-trixi/129089)

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**Author:** [@Deepak](https://discourse.julialang.org/u/Deepak)\
**Replies:** 1\
**Last updated:** [May 20, 2025, 5:17am UTC](https://discourse.julialang.org/t/is-modal-discontinuous-galerkin-implemented-in-trixi/129089 "2025-05-20T05:17:29Z")

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Hello everyone. I want to ask that whether modal DG is implemented in julia or it uses only nodal DG ?

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## [MimiIWG and MimiFUND](https://discourse.julialang.org/t/mimiiwg-and-mimifund/130767)

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**Author:** [@Muhammad\_Asghar](https://discourse.julialang.org/u/Muhammad_Asghar)\
**Replies:** 9\
**Last updated:** [July 16, 2025, 1:35pm UTC](https://discourse.julialang.org/t/mimiiwg-and-mimifund/130767 "2025-07-16T13:35:27Z")

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I can’t resolve error to install MimiIWG and MimiFUND. Can anyone help me to get it installed?

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## [String line continuation](https://discourse.julialang.org/t/string-line-continuation/130757)

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**Author:** [@rokke](https://discourse.julialang.org/u/rokke)\
**Replies:** 14\
**Last updated:** [July 15, 2025, 9:01pm UTC](https://discourse.julialang.org/t/string-line-continuation/130757 "2025-07-15T21:01:05Z")

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the docs make it sound like you can continue strings: “long lines can be broken up” but it’s giving me an error in the repl: julia\> "This is a long \\ ERROR: ParseError: # Error @ REPL\[1\]:1:17 "This is a long \\ # …

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## [Why is Ref() not reflecting the changes](https://discourse.julialang.org/t/why-is-ref-not-reflecting-the-changes/130740)

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**Author:** [@Farouk](https://discourse.julialang.org/u/Farouk)\
**Replies:** 2\
**Last updated:** [July 15, 2025, 1:57pm UTC](https://discourse.julialang.org/t/why-is-ref-not-reflecting-the-changes/130740 "2025-07-15T13:57:41Z")

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Hello I am playing with the Ref{T} and I cannot understand why when doing some updates the changes are visible via the variable holding the Ref and when doing other updates they don’t show up. I would appreciate your hel…

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## [Plotting a heatmap or surface plot](https://discourse.julialang.org/t/plotting-a-heatmap-or-surface-plot/130702)

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**Author:** [@Geegee](https://discourse.julialang.org/u/Geegee)\
**Replies:** 2\
**Last updated:** [July 14, 2025, 3:42pm UTC](https://discourse.julialang.org/t/plotting-a-heatmap-or-surface-plot/130702 "2025-07-14T15:42:31Z")

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Upon reading the tutorial in algebraofgraphics package it sounded really promising. I wanted to plot a heatmap of an image that was recorded with a camera which I wasn’t able to do. Is this just not supported or do I …

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## [Trouble importing Calcium\_jll](https://discourse.julialang.org/t/trouble-importing-calcium-jll/130721)

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**Author:** [@jupiterDescending](https://discourse.julialang.org/u/jupiterDescending)\
**Replies:** 2\
**Last updated:** [July 14, 2025, 10:34pm UTC](https://discourse.julialang.org/t/trouble-importing-calcium-jll/130721 "2025-07-14T22:34:30Z")

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I’m trying to import packages such as AlgebraicNumbers that have Calcium\_jll as a dependency. When I try to do so, I get errors of the form Failed to precompile Calcium\_jll \[fcfa6d1b-d8ce-59d5-8c0a-c0d7f69e4f40\] to "/Us…

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## [Embedding Julia in Windows](https://discourse.julialang.org/t/embedding-julia-in-windows/76693)

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**Author:** [@DanielP](https://discourse.julialang.org/u/DanielP)\
**Replies:** 1\
**Last updated:** [July 12, 2025, 7:06pm UTC](https://discourse.julialang.org/t/embedding-julia-in-windows/76693 "2025-07-12T19:06:21Z")

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Hi, I have tried to call my tested Julia function from C program on Windows 10. I am using gcc compiler (minGW). When I compile, link and launch my program from the IDE (I am using Code::Blocks IDE) it works fine. The co…

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## [A weird issue while adding packages (corrupted double-linked list or Segmentation)](https://discourse.julialang.org/t/a-weird-issue-while-adding-packages-corrupted-double-linked-list-or-segmentation/130629)

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**Author:** [@SolaireZ](https://discourse.julialang.org/u/SolaireZ)\
**Replies:** 12\
**Last updated:** [July 12, 2025, 2:58pm UTC](https://discourse.julialang.org/t/a-weird-issue-while-adding-packages-corrupted-double-linked-list-or-segmentation/130629 "2025-07-12T14:58:31Z")

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I was just trying install FUSE with (On ubuntu 22.04 LTS) using Pkg Pkg.Registry.add(RegistrySpec(url="https://github.com/ProjectTorreyPines/FuseRegistry.jl.git")) Pkg.Registry.add("General") Pkg.add("FUSE") I installe…

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## [Nested loop is slow when indices are in a struct](https://discourse.julialang.org/t/nested-loop-is-slow-when-indices-are-in-a-struct/130639)

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**Author:** [@omicron8](https://discourse.julialang.org/u/omicron8)\
**Replies:** 2\
**Last updated:** [July 11, 2025, 11:31am UTC](https://discourse.julialang.org/t/nested-loop-is-slow-when-indices-are-in-a-struct/130639 "2025-07-11T11:31:03Z")

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I have a function that loops over a 2D array. For the second dimension only some of the indices are used, and they are passed in as a unit range. It seems to make a big difference to performance if the range is part of a…

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## [Weird histogram looking](https://discourse.julialang.org/t/weird-histogram-looking/130601)

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**Author:** [@elisadonati23](https://discourse.julialang.org/u/elisadonati23)\
**Replies:** 4\
**Last updated:** [July 10, 2025, 8:29pm UTC](https://discourse.julialang.org/t/weird-histogram-looking/130601 "2025-07-10T20:29:50Z")

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Dear all, can someone help me to understand why I get this histogram? agent\_adults\_last is 1236145-element Vector{Float64} with balues between 7.0 and 25.0 Never happened to me. it seems that it is a large sample …

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## [Why is the loss function increasing when fitting a line?](https://discourse.julialang.org/t/why-is-the-loss-function-increasing-when-fitting-a-line/130600)

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**Author:** [@\_jovian](https://discourse.julialang.org/u/_jovian)\
**Replies:** 2\
**Last updated:** [July 10, 2025, 1:37pm UTC](https://discourse.julialang.org/t/why-is-the-loss-function-increasing-when-fitting-a-line/130600 "2025-07-10T13:37:12Z")

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Hello everyone, I’m following the “Fitting a Line” from the Flux.jl guide. It works as expected with the given data, as well as when modifying the predicted function (e.g. actual(x) = 3x - 1). I was trying to change th…

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## [Is it okay to learn only Julia, no other language](https://discourse.julialang.org/t/is-it-okay-to-learn-only-julia-no-other-language/117139)

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**Author:** [@Anil\_Beniwal](https://discourse.julialang.org/u/Anil_Beniwal)\
**Replies:** 21\
**Last updated:** [July 9, 2025, 5:08pm UTC](https://discourse.julialang.org/t/is-it-okay-to-learn-only-julia-no-other-language/117139 "2025-07-09T17:08:48Z")

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Hi, I’m new to Julia, learning to code after banging head with pointers in “C” language. Should I bet on julia as first and only language to learn to code. And also I’m self teaching myself. As Julia is a new language th…

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## [3d array Literal](https://discourse.julialang.org/t/3d-array-literal/35310)

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**Author:** [@Sijun](https://discourse.julialang.org/u/Sijun)\
**Replies:** 6\
**Last updated:** [July 8, 2025, 3:41pm UTC](https://discourse.julialang.org/t/3d-array-literal/35310 "2025-07-08T15:41:51Z")

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In C, 3d array literal is written as int arr\[3\]\[3\]\[3\]= { { {11, 12, 13}, {14, 15, 16}, {17, 18, 19} }, { {21, 22, 23}, {24, 25, 26}, {27, 28, 29} }, { {31, 32, 33}, {…

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## [How do you use Comonicon.jl?](https://discourse.julialang.org/t/how-do-you-use-comonicon-jl/45024)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 4\
**Last updated:** [July 8, 2025, 12:27am UTC](https://discourse.julialang.org/t/how-do-you-use-comonicon-jl/45024 "2025-07-08T00:27:41Z")

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I am very confused by the instructions here https://rogerluo.me/Comonicon.jl/ I thought the Getting started should read Put these code into a Julia file.jl Run this some other code In bash run this other code; see tha…

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## [Confusion in The return Keyword](https://discourse.julialang.org/t/confusion-in-the-return-keyword/130525)

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**Author:** [@raman\_kumar](https://discourse.julialang.org/u/raman_kumar)\
**Replies:** 4\
**Last updated:** [July 6, 2025, 7:32pm UTC](https://discourse.julialang.org/t/confusion-in-the-return-keyword/130525 "2025-07-06T19:32:59Z")

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In this code given in Julia documentation i got following results. Is there some discrepancy? julia\> function hypot(x, y) x = abs(x) y = abs(y) if x \> y r = y/x …

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## [Issues with DifferentialEquations compiling](https://discourse.julialang.org/t/issues-with-differentialequations-compiling/126497)

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**Author:** [@matyaspayn](https://discourse.julialang.org/u/matyaspayn)\
**Replies:** 30\
**Last updated:** [July 5, 2025, 10:56am UTC](https://discourse.julialang.org/t/issues-with-differentialequations-compiling/126497 "2025-07-05T10:56:34Z")

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Hello, I am currently learning Julia for my bachelor thesis and have ran into a problem with using DifferentialEquations. When I try to compile DifferentialEquations, these four dependencies error and I cannot see t…

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## [How to parameterize StepRangeLen](https://discourse.julialang.org/t/how-to-parameterize-steprangelen/130338)

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**Author:** [@mwlidar](https://discourse.julialang.org/u/mwlidar)\
**Replies:** 3\
**Last updated:** [July 4, 2025, 7:47am UTC](https://discourse.julialang.org/t/how-to-parameterize-steprangelen/130338 "2025-07-04T07:47:41Z")

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I have a structure with a floating point type parameter for the arrays and I want to include a StepRangeLen with fitting type. How can this be achieved? struct MyType{S\<:Union{Float32, Float64}} data::Vector{S} grid…

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## [Learning to program in Julia, using a powerful debugger](https://discourse.julialang.org/t/learning-to-program-in-julia-using-a-powerful-debugger/130453)

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**Author:** [@skypuppy](https://discourse.julialang.org/u/skypuppy)\
**Replies:** 3\
**Last updated:** [July 3, 2025, 5:47pm UTC](https://discourse.julialang.org/t/learning-to-program-in-julia-using-a-powerful-debugger/130453 "2025-07-03T17:47:06Z")

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Does there exist one? What I’d like to use is the equivalent of a C good debugger for Julia (See SGI’s graphical debugger for examples.. To help me learn Julia, I (the generic ‘I’) could open a package that interests m…

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## [Cannot install Fermi.jl due to version constraints](https://discourse.julialang.org/t/cannot-install-fermi-jl-due-to-version-constraints/130157)

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**Author:** [@Uranium238](https://discourse.julialang.org/u/Uranium238)\
**Replies:** 4\
**Last updated:** [July 3, 2025, 6:03am UTC](https://discourse.julialang.org/t/cannot-install-fermi-jl-due-to-version-constraints/130157 "2025-07-03T06:03:00Z")

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I am trying to install Fermi.jl on the newest stable release of Julia. On doing a fresh install and activating a completely new environment, when I do \] add Fermi, I am met with the following error message : (@v1.11) pk…

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