# Latest

**URL:** https://discourse.julialang.org/latest.md?page=445

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

**Page:** 446

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## [Error loading FileIOExt](https://discourse.julialang.org/t/error-loading-fileioext/112353)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 0\
**Last updated:** [March 31, 2024, 2:21pm UTC](https://discourse.julialang.org/t/error-loading-fileioext/112353 "2024-03-31T14:21:39Z")

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When I type: using Plots I get the following error message: ┌ Warning: Module FileIOExt with build ID ffffffff-ffff-ffff-0000-0a3d1eb7c6d1 is missing from the cache. │ This may mean FileIOExt \[f5f51d8f-5827-5d2e-939b-…

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## [Efficient bit rotate functions: ror, rol...what is the official way for Julia v1?](https://discourse.julialang.org/t/efficient-bit-rotate-functions-ror-rol-what-is-the-official-way-for-julia-v1/19062)

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**Author:** [@rapasite](https://discourse.julialang.org/u/rapasite)\
**Replies:** 5\
**Last updated:** [March 31, 2024, 1:30pm UTC](https://discourse.julialang.org/t/efficient-bit-rotate-functions-ror-rol-what-is-the-official-way-for-julia-v1/19062 "2024-03-31T13:30:39Z")

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Hi, I found this https://github.com/JuliaLang/julia/issues/11592 but I can not understand what should I do for a UInt64 or any other arbitrary 0b.... Am I missing something in the doc? Thanks you

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## [Understanding Pkg.add() and Environments](https://discourse.julialang.org/t/understanding-pkg-add-and-environments/112313)

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**Author:** [@JacobC](https://discourse.julialang.org/u/JacobC)\
**Replies:** 9\
**Last updated:** [March 31, 2024, 7:25am UTC](https://discourse.julialang.org/t/understanding-pkg-add-and-environments/112313 "2024-03-31T07:25:06Z")

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TLDR: When I add a package Julia installs the package and any dependencies (expected), then it says Precompiling project and appears to go through every package that I have ever used and spends a lot of time compiling ev…

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## [Efficient way to calculate the trace distance](https://discourse.julialang.org/t/efficient-way-to-calculate-the-trace-distance/112343)

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**Author:** [@jiyashxi](https://discourse.julialang.org/u/jiyashxi)\
**Replies:** 1\
**Last updated:** [March 31, 2024, 4:49am UTC](https://discourse.julialang.org/t/efficient-way-to-calculate-the-trace-distance/112343 "2024-03-31T04:49:06Z")

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Hi, I am trying to calculate the trace distance of two matrices, which is defined as in trace distance. I noticed that Julia provides opnorm function but it seems that this is not what I want. I wonder if there is some …

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## [Gradients of strain](https://discourse.julialang.org/t/gradients-of-strain/112344)

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**Author:** [@mary](https://discourse.julialang.org/u/mary)\
**Replies:** 0\
**Last updated:** [March 31, 2024, 4:09am UTC](https://discourse.julialang.org/t/gradients-of-strain/112344 "2024-03-31T04:09:37Z")

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HI, I want to take the derivative of strain with respect to displacement without using the the shape functions and find the gradients in cells in gridap (I can not figure out this derivative mathematically). I used this…

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## [Weird floating point under/overflow behavior](https://discourse.julialang.org/t/weird-floating-point-under-overflow-behavior/112340)

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**Author:** [@pxshen](https://discourse.julialang.org/u/pxshen)\
**Replies:** 3\
**Last updated:** [March 31, 2024, 3:00am UTC](https://discourse.julialang.org/t/weird-floating-point-under-overflow-behavior/112340 "2024-03-31T03:00:28Z")

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Expect to underflow to 0 and overflow to biggest value, but results below seem opposite? I train ML and had nan from dividing by big # in gradients julia\> 1f0/2^64 Inf32 julia\> 1f0/(2^64) Inf32 julia\> 1f0\*(2^64) 0.0f0…

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## [Smooth approximation to max(0, x)](https://discourse.julialang.org/t/smooth-approximation-to-max-0-x/109383)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 13\
**Last updated:** [March 31, 2024, 1:43am UTC](https://discourse.julialang.org/t/smooth-approximation-to-max-0-x/109383 "2024-03-31T01:43:42Z")

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I need a “smooth” approximation f to x \\to \\max(0, x), such that \\lim\_{x \\to -\\infty} f(x) = 0, \\lim\_{x \\to \\infty} f(x) = x, f(x) \> 0, f'(x) \> 0, both continuous; ideally continuous higher derivatives not too expensiv…

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## [Using a type parameter vs abstract type in function signature](https://discourse.julialang.org/t/using-a-type-parameter-vs-abstract-type-in-function-signature/112339)

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**Author:** [@mdsalerno](https://discourse.julialang.org/u/mdsalerno)\
**Replies:** 2\
**Last updated:** [March 31, 2024, 12:18am UTC](https://discourse.julialang.org/t/using-a-type-parameter-vs-abstract-type-in-function-signature/112339 "2024-03-31T00:18:52Z")

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I’ve written the following function: function all\_your\_base(digits::Vector{Integer}, base\_in, base\_out) sum(digits) ≠ 0 || return(\[0\]) n = digits .\* base\_in .^ (length(digits)-1:-1:0) |\> sum res = \[\] fo…

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## [Essay: Julia and Projective Geometric Algebra](https://discourse.julialang.org/t/essay-julia-and-projective-geometric-algebra/92767)

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**Author:** [@g2g](https://discourse.julialang.org/u/g2g)\
**Replies:** 9\
**Last updated:** [March 28, 2024, 7:19pm UTC](https://discourse.julialang.org/t/essay-julia-and-projective-geometric-algebra/92767 "2024-03-28T19:19:06Z")

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There appears to be a lot of overlap in the fields of science interested in Julia and the fields of science interested in geometric algebra. Perhaps the two communities would benefit from each other? In an attempt to en…

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## [Slow and Memory intensive For Loop](https://discourse.julialang.org/t/slow-and-memory-intensive-for-loop/112304)

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**Author:** [@soumen261](https://discourse.julialang.org/u/soumen261)\
**Replies:** 6\
**Last updated:** [March 30, 2024, 10:44pm UTC](https://discourse.julialang.org/t/slow-and-memory-intensive-for-loop/112304 "2024-03-30T22:44:51Z")

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Hi Julians, I am still a novice in Julia. I am writing a code to import/read a total 16 data (.txt) files each having 504\*1025 matrix. Essentially trying to make a 3D data cube from the 2D datasets using a For loop. But…

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## [How to leave only unique rows of array](https://discourse.julialang.org/t/how-to-leave-only-unique-rows-of-array/112332)

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**Author:** [@programista](https://discourse.julialang.org/u/programista)\
**Replies:** 5\
**Last updated:** [March 30, 2024, 8:26pm UTC](https://discourse.julialang.org/t/how-to-leave-only-unique-rows-of-array/112332 "2024-03-30T20:26:26Z")

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These are two columns of a string matrix. How to leave only unique rows of these 12 array rows? : Kalinka surname Kalinka surname Kalinka surname Kalinka geographical\_name Kalinka geographical\_name Kalinka geographical\_…

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## [ApproxFun.jl multiplying fourier series and cosine/sine series issue](https://discourse.julialang.org/t/approxfun-jl-multiplying-fourier-series-and-cosine-sine-series-issue/110937)

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**Author:** [@yewalenikhil65](https://discourse.julialang.org/u/yewalenikhil65)\
**Replies:** 4\
**Last updated:** [March 30, 2024, 7:48pm UTC](https://discourse.julialang.org/t/approxfun-jl-multiplying-fourier-series-and-cosine-sine-series-issue/110937 "2024-03-30T19:48:12Z")

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Hi @dlfivefifty I am using ApproxFun.jl along with Num type from SYmbolics to work with sin/cosine/Fourier series as follows: julia\> myg =Fun(CosSpace(), rand(10)); myf = Fun(SinSpace(), rand(10)); using Symbolics a…

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## [(Plots.jl) aspect\_ratio=1.0 for 3d plot](https://discourse.julialang.org/t/plots-jl-aspect-ratio-1-0-for-3d-plot/58607)

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**Author:** [@iHany](https://discourse.julialang.org/u/iHany)\
**Replies:** 16\
**Last updated:** [March 30, 2024, 7:43pm UTC](https://discourse.julialang.org/t/plots-jl-aspect-ratio-1-0-for-3d-plot/58607 "2024-03-30T19:43:25Z")

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Issue I don’t know how to set aspect\_ratio=:equal for 3d plot (like axis\_equal in MATLAB). It seems that only x and y axes’ aspect ratio are equal. Example code using Plots function test() N = 10 xs = range(0…

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## [Constrained Optimization of a "taxation" curve not working Optimization.jl / Ipopt](https://discourse.julialang.org/t/constrained-optimization-of-a-taxation-curve-not-working-optimization-jl-ipopt/112317)

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**Author:** [@dlakelan](https://discourse.julialang.org/u/dlakelan)\
**Replies:** 11\
**Last updated:** [March 30, 2024, 6:08pm UTC](https://discourse.julialang.org/t/constrained-optimization-of-a-taxation-curve-not-working-optimization-jl-ipopt/112317 "2024-03-30T18:08:34Z")

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I was having some discussions online on Mastodon, and advocating that we could simplify our tax code to a flat tax + UBI and that this is kind of “near optimal” in some sense. I wrote up a notebook about it… GitHub - dl…

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## [How to delete dataset in hdf5 file ? GPT dont know!](https://discourse.julialang.org/t/how-to-delete-dataset-in-hdf5-file-gpt-dont-know/112322)

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**Author:** [@programista](https://discourse.julialang.org/u/programista)\
**Replies:** 1\
**Last updated:** [March 30, 2024, 5:10pm UTC](https://discourse.julialang.org/t/how-to-delete-dataset-in-hdf5-file-gpt-dont-know/112322 "2024-03-30T17:10:29Z")

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How to delete dataset “y” from group “male” ? julia\> fid\["male"\] ?? HDF5.Group: /male (file: miasta.h5) ├─ ?? x └─ ?? y Paul

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## [Python pcolormesh() alternative in Julia](https://discourse.julialang.org/t/python-pcolormesh-alternative-in-julia/111885)

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**Author:** [@raman\_kumar](https://discourse.julialang.org/u/raman_kumar)\
**Replies:** 15\
**Last updated:** [March 30, 2024, 5:03am UTC](https://discourse.julialang.org/t/python-pcolormesh-alternative-in-julia/111885 "2024-03-30T05:03:02Z")

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I want to get equivalent plot in Julia that i have using Python pcolormesh() function. Here x and z are two 270x100 matrices. You can download folder containing that Python script and data at VelocPythJul.tar.gz - Google…

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## [How to improve the performance of a function generating a Jacobian with "Toeplitz" structure](https://discourse.julialang.org/t/how-to-improve-the-performance-of-a-function-generating-a-jacobian-with-toeplitz-structure/112286)

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**Author:** [@RayleighLord](https://discourse.julialang.org/u/RayleighLord)\
**Replies:** 5\
**Last updated:** [March 30, 2024, 2:41pm UTC](https://discourse.julialang.org/t/how-to-improve-the-performance-of-a-function-generating-a-jacobian-with-toeplitz-structure/112286 "2024-03-30T14:41:37Z")

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I have a single variable function g(x) where x(t) is a periodic function. I am interested in obtaining the jacobian of the Fourier harmonics of g when differentiated with respect to the harmonics of x(t). It is well kno…

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## [How to catch a instability in an ODE using Julia?](https://discourse.julialang.org/t/how-to-catch-a-instability-in-an-ode-using-julia/112324)

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**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 2\
**Last updated:** [March 30, 2024, 12:56pm UTC](https://discourse.julialang.org/t/how-to-catch-a-instability-in-an-ode-using-julia/112324 "2024-03-30T12:56:43Z")

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I am modeling the interaction between bacteria and phages with DifferentialEquations and making an interactive plot with GLMakie. The plot works, but is it possible to catch instability in the ODEs so that I can run a l…

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## [Malicious code in XZ\_jll.jl (v5.6.1+0) ; it could pose a problem?](https://discourse.julialang.org/t/malicious-code-in-xz-jll-jl-v5-6-1-0-it-could-pose-a-problem/112311)

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**Author:** [@ImreSamu](https://discourse.julialang.org/u/ImreSamu)\
**Replies:** 3\
**Last updated:** [March 30, 2024, 12:41pm UTC](https://discourse.julialang.org/t/malicious-code-in-xz-jll-jl-v5-6-1-0-it-could-pose-a-problem/112311 "2024-03-30T12:41:02Z")

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Based on my examination of the package https://juliahub.com/ui/Packages/General/XZ\_jll - XZ\_jll.jl (v5.6.1+0) it appears to be connected to a security issue detailed here: https://www.phoronix.com/news/XZ-CVE-2024-3094 …

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## [\[ANN\] MetidaBioeq.jl - Bioequivalence estimation](https://discourse.julialang.org/t/ann-metidabioeq-jl-bioequivalence-estimation/97512)

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**Author:** [@PharmCat](https://discourse.julialang.org/u/PharmCat)\
**Replies:** 1\
**Last updated:** [March 30, 2024, 12:15pm UTC](https://discourse.julialang.org/t/ann-metidabioeq-jl-bioequivalence-estimation/97512 "2024-03-30T12:15:45Z")

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Soon MetidaBioeq.jl will be in registry. This is a first release and it support only basic bioequivalence estimation in accordance with: EMA: GUIDELINE ON THE INVESTIGATION OF BIOEQUIVALENCE EMA: GUIDELINE ON THE I…

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## [Computer Science Engineer on Functional-Structural Plant Models in Montpellier (01/05 - 31/12/2024)](https://discourse.julialang.org/t/computer-science-engineer-on-functional-structural-plant-models-in-montpellier-01-05-31-12-2024/112093)

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**Author:** [@rvezy](https://discourse.julialang.org/u/rvezy)\
**Replies:** 11\
**Last updated:** [March 30, 2024, 11:14am UTC](https://discourse.julialang.org/t/computer-science-engineer-on-functional-structural-plant-models-in-montpellier-01-05-31-12-2024/112093 "2024-03-30T11:14:49Z")

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:star2:We are recruiting someone specialized in scientific computing to work on multi-scale modelling of plants and vegetation :herb: in pure Julia, mainly: VirtualPlantLab/PlantSimEngine.jl: A simulation engine for mo…

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## [Agent-based small-economy modeling](https://discourse.julialang.org/t/agent-based-small-economy-modeling/112309)

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**Author:** [@Chuck\_Harrison](https://discourse.julialang.org/u/Chuck_Harrison)\
**Replies:** 1\
**Last updated:** [March 30, 2024, 9:42am UTC](https://discourse.julialang.org/t/agent-based-small-economy-modeling/112309 "2024-03-30T09:42:45Z")

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I am starting a project to model local economies using complementary currencies. I expect to start with Stef Kuyper’s EconoSim.jl framework(GitHub - HapponomyOrg/EconoSim.jl: Economic simulation tools). I am inexperience…

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## [AoG plotting: column name :x not found in data frame](https://discourse.julialang.org/t/aog-plotting-column-name-x-not-found-in-data-frame/112248)

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**Author:** [@shrdlu](https://discourse.julialang.org/u/shrdlu)\
**Replies:** 5\
**Last updated:** [March 30, 2024, 9:14am UTC](https://discourse.julialang.org/t/aog-plotting-column-name-x-not-found-in-data-frame/112248 "2024-03-30T09:14:47Z")

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Hi, I’m trying the AlgebraOfGraphics page demo for heatmap-style visualization (Visual · Algebra of Graphics) using my own local data. I have no issues importing the external .tsv matrix file, but the process throws an…

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## [How to pass an arbitrary number of macro arguments from one macro to another? (a bit like splatting)](https://discourse.julialang.org/t/how-to-pass-an-arbitrary-number-of-macro-arguments-from-one-macro-to-another-a-bit-like-splatting/112288)

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**Author:** [@Torkel](https://discourse.julialang.org/u/Torkel)\
**Replies:** 7\
**Last updated:** [March 29, 2024, 11:27pm UTC](https://discourse.julialang.org/t/how-to-pass-an-arbitrary-number-of-macro-arguments-from-one-macro-to-another-a-bit-like-splatting/112288 "2024-03-29T23:27:05Z")

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I have a macro which does stuff depending on how many inputs there are macro my\_macro(arg1) println("We got one argument.") sum = 1 if arg1 isa Int64 sum = sum + arg1 end sum end macro my\_mac…

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## [Best data structure for recursive functions?](https://discourse.julialang.org/t/best-data-structure-for-recursive-functions/112289)

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**Author:** [@phantom](https://discourse.julialang.org/u/phantom)\
**Replies:** 6\
**Last updated:** [March 29, 2024, 11:26pm UTC](https://discourse.julialang.org/t/best-data-structure-for-recursive-functions/112289 "2024-03-29T23:26:51Z")

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Hi Hope everyone is having a good friday. Suppose a function tests for an initial condition prior to running an inner function on elements of a series of datasets. If the initial condition fails, the function skips to …

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## [Is Julia Forem unused?](https://discourse.julialang.org/t/is-julia-forem-unused/110760)

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**Author:** [@indymnv](https://discourse.julialang.org/u/indymnv)\
**Replies:** 21\
**Last updated:** [March 29, 2024, 8:16pm UTC](https://discourse.julialang.org/t/is-julia-forem-unused/110760 "2024-03-29T20:16:27Z")

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I connected to Julia Forem recently and I have seen and reported a lot of spam posts, I am wondering if the content is moving to other website now. Also, if there is need for help. I could help with that.

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## [Type stability and heterogeneous collections](https://discourse.julialang.org/t/type-stability-and-heterogeneous-collections/112293)

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**Author:** [@andreapasquale94](https://discourse.julialang.org/u/andreapasquale94)\
**Replies:** 5\
**Last updated:** [March 29, 2024, 5:36pm UTC](https://discourse.julialang.org/t/type-stability-and-heterogeneous-collections/112293 "2024-03-29T17:36:09Z")

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I am working on a library where I cannot avoid heterogeneous collections, and I want type-stable code. I’m trying to improve my understanding of how the compiler behaves in those cases (and in general). There are alrea…

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## [Update package](https://discourse.julialang.org/t/update-package/112227)

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**Author:** [@KianH](https://discourse.julialang.org/u/KianH)\
**Replies:** 7\
**Last updated:** [March 29, 2024, 5:18pm UTC](https://discourse.julialang.org/t/update-package/112227 "2024-03-29T17:18:14Z")

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Hello! I am trying to update my Julia packages. I am working with Julia v1.10 and when I try to update the packages, the package version does not change. This seems to only be a problem for some packages and not all pac…

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## [Libgobject-2.0.so.0: undefined symbol: g\_dir\_unref](https://discourse.julialang.org/t/libgobject-2-0-so-0-undefined-symbol-g-dir-unref/112301)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 1\
**Last updated:** [March 29, 2024, 4:58pm UTC](https://discourse.julialang.org/t/libgobject-2-0-so-0-undefined-symbol-g-dir-unref/112301 "2024-03-29T16:58:01Z")

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I currently get the following error when I try to create a system image: ERROR: LoadError: InitError: could not load library “/home/ufechner/.julia/artifacts/648a32a349aac06f19b6bfed47f0b822b4ef28c3/lib/libgio-2.0.so” …

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## [Make variable available on all workers](https://discourse.julialang.org/t/make-variable-available-on-all-workers/112302)

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**Author:** [@Igor\_Douven](https://discourse.julialang.org/u/Igor_Douven)\
**Replies:** 0\
**Last updated:** [March 29, 2024, 4:31pm UTC](https://discourse.julialang.org/t/make-variable-available-on-all-workers/112302 "2024-03-29T16:31:43Z")

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Hi all, I’d like to run an evolutionary algorithm which starts with a population of agents and then lets that evolve for a number of generations. To make this not too slow, parts of the algorithm are parallelized. If I …

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