# Latest

**URL:** https://discourse.julialang.org/latest.md?page=197

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

**Page:** 198

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## [How to improve CI.yml to avoid running a test-set twice](https://discourse.julialang.org/t/how-to-improve-ci-yml-to-avoid-running-a-test-set-twice/127258)

<div class="topic-metadata">

**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 4\
**Last updated:** [March 24, 2025, 10:33am UTC](https://discourse.julialang.org/t/how-to-improve-ci-yml-to-avoid-running-a-test-set-twice/127258 "2025-03-24T10:33:29Z")

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Im my CI.yml file I have: matrix: version: - '1.10' - '1' - 'pre' This is intended. I want to test with the latest stable Julia release, the latest Julia release and any upco…

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## [Sundials solution greatly deviates for large perturbation, why?](https://discourse.julialang.org/t/sundials-solution-greatly-deviates-for-large-perturbation-why/127147)

<div class="topic-metadata">

**Author:** [@dsousoun](https://discourse.julialang.org/u/dsousoun)\
**Replies:** 12\
**Last updated:** [March 24, 2025, 10:13am UTC](https://discourse.julialang.org/t/sundials-solution-greatly-deviates-for-large-perturbation-why/127147 "2025-03-24T10:13:05Z")

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Hello all, First of, I am sorry for the massive code text. The problem: in the following for small enough perturbations in P\_in (ie jump = 1e-2), the IDA solver matches perfectly my solver. However, for anything larger…

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## [Floating point exceptions on the gpu](https://discourse.julialang.org/t/floating-point-exceptions-on-the-gpu/127292)

<div class="topic-metadata">

**Author:** [@MrBelette](https://discourse.julialang.org/u/MrBelette)\
**Replies:** 1\
**Last updated:** [March 24, 2025, 8:16am UTC](https://discourse.julialang.org/t/floating-point-exceptions-on-the-gpu/127292 "2025-03-24T08:16:08Z")

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I’m wondering how people treat floating point exceptions on the gpu, such as division by zero or overflow? I’m not sure about other gpus, but I believe that Nvidia gpus don’t have hardware capability to detect IEEE fp e…

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## [Update optimization model by changing variables to coefficients](https://discourse.julialang.org/t/update-optimization-model-by-changing-variables-to-coefficients/124642)

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**Author:** [@max](https://discourse.julialang.org/u/max)\
**Replies:** 11\
**Last updated:** [March 24, 2025, 4:52am UTC](https://discourse.julialang.org/t/update-optimization-model-by-changing-variables-to-coefficients/124642 "2025-03-24T04:52:45Z")

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Hi there, :slight\_smile: I am trying to extract shadow prices out of a MIQP model. In order to do this I want to “fix” the mixed integer variables after a first solving and then extract the duals. Here’s a minimal work…

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## [Julia Broadcasting Issue with SubArray in Complex Expressions](https://discourse.julialang.org/t/julia-broadcasting-issue-with-subarray-in-complex-expressions/127269)

<div class="topic-metadata">

**Author:** [@chooron](https://discourse.julialang.org/u/chooron)\
**Replies:** 2\
**Last updated:** [March 23, 2025, 6:35am UTC](https://discourse.julialang.org/t/julia-broadcasting-issue-with-subarray-in-complex-expressions/127269 "2025-03-23T06:35:53Z")

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I’m encountering an issue with Julia broadcasting when working with SubArrays in complex nested expressions. When using @views to create SubArrays and then applying broadcasting with @. to complex expressions, I get type…

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## [Subtyped parameters in constructors](https://discourse.julialang.org/t/subtyped-parameters-in-constructors/127287)

<div class="topic-metadata">

**Author:** [@Deduction42](https://discourse.julialang.org/u/Deduction42)\
**Replies:** 4\
**Last updated:** [March 24, 2025, 12:01am UTC](https://discourse.julialang.org/t/subtyped-parameters-in-constructors/127287 "2025-03-24T00:01:01Z")

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I was playing around with vague constructors and I noticed some very interesting and useful behavior of arrays. I can use “subtype” notation in array constructors! julia\> S = Diagonal(randn(5)) 5×5 Diagonal{Float64, Vec…

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## [Shorter way to rename property, with Accessors](https://discourse.julialang.org/t/shorter-way-to-rename-property-with-accessors/127256)

<div class="topic-metadata">

**Author:** [@jar1](https://discourse.julialang.org/u/jar1)\
**Replies:** 16\
**Last updated:** [March 23, 2025, 8:51pm UTC](https://discourse.julialang.org/t/shorter-way-to-rename-property-with-accessors/127256 "2025-03-23T20:51:47Z")

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How to do rename with Accessors? This is too long. julia\> let x = (;a=1) @delete (@insert x.b = x.a).a end (b = 1,)

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## [Using Symbolics & Nemo; Unexpected roots of simple 2nd degree polynomial equation](https://discourse.julialang.org/t/using-symbolics-nemo-unexpected-roots-of-simple-2nd-degree-polynomial-equation/127281)

<div class="topic-metadata">

**Author:** [@theo.bruelhart](https://discourse.julialang.org/u/theo.bruelhart)\
**Replies:** 2\
**Last updated:** [March 23, 2025, 8:10pm UTC](https://discourse.julialang.org/t/using-symbolics-nemo-unexpected-roots-of-simple-2nd-degree-polynomial-equation/127281 "2025-03-23T20:10:40Z")

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\[Issue\] Unexpected roots of simple 2nd degree polynomial equation using Symbolics.jl and Nemo.jl Obtained results: \[(1//2)\*√(4y), (-1//2)\*√(4y)\] Expected result: \[√(y), -√(y)\] \[Environment\] Linux thinkpad 6.1.0-32-…

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## [Nested Benders with MIP/LP solvers](https://discourse.julialang.org/t/nested-benders-with-mip-lp-solvers/126831)

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**Author:** [@PffTahsan](https://discourse.julialang.org/u/PffTahsan)\
**Replies:** 11\
**Last updated:** [March 23, 2025, 2:13pm UTC](https://discourse.julialang.org/t/nested-benders-with-mip-lp-solvers/126831 "2025-03-23T14:13:03Z")

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I want to solve a nested optimization problem using Benders decomposition, where the first stage relies on the second stage, and the second stage relies on the third stage. The challenge is that the second stage is updat…

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## [DataFrames: \`@combine\` only if a condition is met](https://discourse.julialang.org/t/dataframes-combine-only-if-a-condition-is-met/127232)

<div class="topic-metadata">

**Author:** [@hendri54](https://discourse.julialang.org/u/hendri54)\
**Replies:** 10\
**Last updated:** [March 23, 2025, 12:44pm UTC](https://discourse.julialang.org/t/dataframes-combine-only-if-a-condition-is-met/127232 "2025-03-23T12:44:20Z")

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How can I compute a variable with @combine only if some condition is met? MWE: using DataFrames, DataFramesMeta dfTmp = DataFrame(y = 1:3, x = 10:12) @combine dfTmp begin # Always compute \`a\` :a = :y \* 2; #…

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## [Run c++ app with embedded julia on a machine without julia installation](https://discourse.julialang.org/t/run-c-app-with-embedded-julia-on-a-machine-without-julia-installation/127274)

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**Author:** [@mitrandirsergey](https://discourse.julialang.org/u/mitrandirsergey)\
**Replies:** 3\
**Last updated:** [March 23, 2025, 11:40am UTC](https://discourse.julialang.org/t/run-c-app-with-embedded-julia-on-a-machine-without-julia-installation/127274 "2025-03-23T11:40:08Z")

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Hi. Is it possible to provide julia dll along with my exe file, so it could be run on a PC without julia installation? I found out an example to dynamically load julia (which is quite old) But how to provide julia mo…

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## [Error: Missing source file for Base.PkgId(Base.UUID("..."))](https://discourse.julialang.org/t/error-missing-source-file-for-base-pkgid-base-uuid/127272)

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**Author:** [@yolhan\_mannes](https://discourse.julialang.org/u/yolhan_mannes)\
**Replies:** 1\
**Last updated:** [March 23, 2025, 10:02am UTC](https://discourse.julialang.org/t/error-missing-source-file-for-base-pkgid-base-uuid/127272 "2025-03-23T10:02:45Z")

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I get a weird error while trying to add an extension, Maybe I did something wrong : 1- added the folder ext and the file “BloodFlowTrixiDataInterpolationsExt.jl” in it. 2- added DataInterpolations.jl as a weakdeps \[we…

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## [Seemingly extension of example in SciMLOperators doesn't work](https://discourse.julialang.org/t/seemingly-extension-of-example-in-scimloperators-doesnt-work/127241)

<div class="topic-metadata">

**Author:** [@Veenty](https://discourse.julialang.org/u/Veenty)\
**Replies:** 1\
**Last updated:** [March 23, 2025, 6:46am UTC](https://discourse.julialang.org/t/seemingly-extension-of-example-in-scimloperators-doesnt-work/127241 "2025-03-23T06:46:10Z")

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JUst following the tutorial I would like to be able to define operator L6, as follows N = 4 f = (u, p, t) -\> u .\* u M = MatrixOperator(rand(N, N)) D = DiagonalOperator(rand(N)) F = FunctionOperator(f, zeros(N), zeros(…

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## [Is matrix multiplication not associative?](https://discourse.julialang.org/t/is-matrix-multiplication-not-associative/127231)

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**Author:** [@Yeguarr](https://discourse.julialang.org/u/Yeguarr)\
**Replies:** 22\
**Last updated:** [March 23, 2025, 2:11am UTC](https://discourse.julialang.org/t/is-matrix-multiplication-not-associative/127231 "2025-03-23T02:11:43Z")

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Hi! I have a very simple code snippet: let B = \[1;1\] K = \[1 2\] x = \[1;2\] (B\*K)\*x #Works fine B\*(K\*x) #MethodError: no method matching \*(::Vector{Int64}, ::Vector{Int64}) end It seems that Julia automatically conv…

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## [What's your workflow to develop packages with complex dependencies?](https://discourse.julialang.org/t/whats-your-workflow-to-develop-packages-with-complex-dependencies/127246)

<div class="topic-metadata">

**Author:** [@benc](https://discourse.julialang.org/u/benc)\
**Replies:** 5\
**Last updated:** [March 23, 2025, 12:51am UTC](https://discourse.julialang.org/t/whats-your-workflow-to-develop-packages-with-complex-dependencies/127246 "2025-03-23T00:51:03Z")

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Hi all, I developed quite a few small packages with self-contained functionality, but inevitably during development I need complex dependencies (eg. Plots.jl) for functionality not required by the package itself, but re…

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## [Ipopt's "local" optimum can be very substandard](https://discourse.julialang.org/t/ipopts-local-optimum-can-be-very-substandard/127217)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 8\
**Last updated:** [March 23, 2025, 12:15am UTC](https://discourse.julialang.org/t/ipopts-local-optimum-can-be-very-substandard/127217 "2025-03-23T00:15:15Z")

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Continuing the discussion from The solution deteriorates if the domain of decisions is improperly set when using Ipopt: The title is expounded with 3 examples, where the result of the first one is completely unaccepta…

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## [Why does my iterable allocate?](https://discourse.julialang.org/t/why-does-my-iterable-allocate/86216)

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**Author:** [@Lilith](https://discourse.julialang.org/u/Lilith)\
**Replies:** 18\
**Last updated:** [March 22, 2025, 11:25pm UTC](https://discourse.julialang.org/t/why-does-my-iterable-allocate/86216 "2025-03-22T23:25:47Z")

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I ran into unexpected allocations in a complex iterator and was able to simplify it down into this MWE which uses complex logic to always yield nothing. struct MyIter end Base.iterate(::MyIter) = (nothing, \[true\]) func…

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## [JuliaCon acceptances are out!](https://discourse.julialang.org/t/juliacon-acceptances-are-out/127182)

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**Author:** [@kslimes](https://discourse.julialang.org/u/kslimes)\
**Replies:** 1\
**Last updated:** [March 22, 2025, 7:23pm UTC](https://discourse.julialang.org/t/juliacon-acceptances-are-out/127182 "2025-03-22T19:23:00Z")

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Thank you to everyone who submitted a proposal for JuliaCon 2025, and to all the minisymposia organizers and reviewers for reviewing proposals. We have sent out acceptance and rejection emails for all proposals except th…

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## [Conditional exact integration in ODE solving](https://discourse.julialang.org/t/conditional-exact-integration-in-ode-solving/127267)

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**Author:** [@BdeKoning](https://discourse.julialang.org/u/BdeKoning)\
**Replies:** 2\
**Last updated:** [March 22, 2025, 6:57pm UTC](https://discourse.julialang.org/t/conditional-exact-integration-in-ode-solving/127267 "2025-03-22T18:57:53Z")

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Say in my ODE problem I have an equation like this: \\frac{\\text{d}u\_i}{\\text{d}t} = r(\\mathbf{u})A(t) Here A(t) is a known non-negative interpolation function and r(\\mathbf{u}) is what we call a ‘reduction factor’; it…

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## [CUDA perf on Int types](https://discourse.julialang.org/t/cuda-perf-on-int-types/127263)

<div class="topic-metadata">

**Author:** [@yolhan\_mannes](https://discourse.julialang.org/u/yolhan_mannes)\
**Replies:** 0\
**Last updated:** [March 22, 2025, 5:01pm UTC](https://discourse.julialang.org/t/cuda-perf-on-int-types/127263 "2025-03-22T17:01:49Z")

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I wonder why CUDA mul! performance isn’t that good on Int32 using CUDA N = 2^10 A = CUDA.ones(Int32,N, N) B = CUDA.ones(Int32,N, N) CUDA.@time A\*B A = CUDA.ones(Float32,N, N) B = CUDA.ones(Float32,N, N) CUDA.@time A\*B …

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## [Is there a way to select the type of indices Ti with sprand()?](https://discourse.julialang.org/t/is-there-a-way-to-select-the-type-of-indices-ti-with-sprand/127259)

<div class="topic-metadata">

**Author:** [@AntoineBut](https://discourse.julialang.org/u/AntoineBut)\
**Replies:** 1\
**Last updated:** [March 22, 2025, 12:15pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-select-the-type-of-indices-ti-with-sprand/127259 "2025-03-22T12:15:21Z")

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The function sprand() has methods to specify the type of the generated elements {Tv}. But a SparseArray has two type parameters, the second being the type used to stores the indices {Ti}. Does anyone have a magic trick t…

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## [Interacting agents in discrete event simulations](https://discourse.julialang.org/t/interacting-agents-in-discrete-event-simulations/122070)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 11\
**Last updated:** [March 22, 2025, 12:05pm UTC](https://discourse.julialang.org/t/interacting-agents-in-discrete-event-simulations/122070 "2025-03-22T12:05:05Z")

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Hello, I would like to develop a simulation in which agents interact in pairs for a random period of time. While a pair is interacting, the agents in the pair are “busy”, meaning they are not available to interact with …

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## [Makie: integrating a marker into a string](https://discourse.julialang.org/t/makie-integrating-a-marker-into-a-string/127257)

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**Author:** [@Gravlax](https://discourse.julialang.org/u/Gravlax)\
**Replies:** 0\
**Last updated:** [March 22, 2025, 8:14am UTC](https://discourse.julialang.org/t/makie-integrating-a-marker-into-a-string/127257 "2025-03-22T08:14:59Z")

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I’m trying to make a figure in which I’d like a marker to appear in the tile. For example, a dummy figure title is: title = L"$$Panel 1 (star6)" where star6 refers to a marker appearing on another panel. Is there any…

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## [Automatically convert a Pluto Cell to markdown](https://discourse.julialang.org/t/automatically-convert-a-pluto-cell-to-markdown/69012)

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**Author:** [@Bastien](https://discourse.julialang.org/u/Bastien)\
**Replies:** 12\
**Last updated:** [March 22, 2025, 9:03am UTC](https://discourse.julialang.org/t/automatically-convert-a-pluto-cell-to-markdown/69012 "2025-03-22T09:03:45Z")

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Hi, I am thinking of using Pluto as a sort of Electronic Lab Notebook from where I could drive an experiment and do analysis on the fly. To avoid running a command (e.g. measuring the transmission of a device with a VNA…

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## [Enzyme computing the Hessian(?)](https://discourse.julialang.org/t/enzyme-computing-the-hessian/127197)

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**Author:** [@miguelborrero](https://discourse.julialang.org/u/miguelborrero)\
**Replies:** 6\
**Last updated:** [March 22, 2025, 7:26am UTC](https://discourse.julialang.org/t/enzyme-computing-the-hessian/127197 "2025-03-22T07:26:07Z")

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Hi there! It seems like the (fantastic!) package Enzyme supports the computation of the Hessian times a vector but not the Hessian itself. Is this just a matter of time? or is the Hessian too expensive as to implement i…

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## [MethodError: no method matching UnitCommitmentData](https://discourse.julialang.org/t/methoderror-no-method-matching-unitcommitmentdata/127253)

<div class="topic-metadata">

**Author:** [@daiyucan](https://discourse.julialang.org/u/daiyucan)\
**Replies:** 0\
**Last updated:** [March 22, 2025, 6:25am UTC](https://discourse.julialang.org/t/methoderror-no-method-matching-unitcommitmentdata/127253 "2025-03-22T06:25:43Z")

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using JuMP using HiGHS 定义UnitCommitmentData结构 struct UnitCommitmentData demand::Float64 pmin::Vector{Float64} pmax::Vector{Float64} cfix::Vector{Float64} cvar::Vector{Float64} end 构建Unit Commitment模型 function bu…

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## [Precompilation error when evaling into a module in the \_\_init\_\_ function](https://discourse.julialang.org/t/precompilation-error-when-evaling-into-a-module-in-the-init-function/126935)

<div class="topic-metadata">

**Author:** [@brianguenter](https://discourse.julialang.org/u/brianguenter)\
**Replies:** 3\
**Last updated:** [March 22, 2025, 5:20am UTC](https://discourse.julialang.org/t/precompilation-error-when-evaling-into-a-module-in-the-init-function/126935 "2025-03-22T05:20:45Z")

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Is this allowed? module PackageProblem function \_\_init\_\_() @eval begin struct NewType a::Float64 end const b = NewType(1.0) end end The package loads fine julia\> using Pac…

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## [Pluto notebook is slower than REPL](https://discourse.julialang.org/t/pluto-notebook-is-slower-than-repl/127145)

<div class="topic-metadata">

**Author:** [@contejuz](https://discourse.julialang.org/u/contejuz)\
**Replies:** 6\
**Last updated:** [March 22, 2025, 2:43am UTC](https://discourse.julialang.org/t/pluto-notebook-is-slower-than-repl/127145 "2025-03-22T02:43:32Z")

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Is there any reason a Pluto notebook can be slower than the REPL? When I use @time, it seems like both take the same amount of time to run a particular function (involving sampling from a probabilistic program using Gen.…

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## [Cannot recreate JumpProcess example in Catalyst](https://discourse.julialang.org/t/cannot-recreate-jumpprocess-example-in-catalyst/127248)

<div class="topic-metadata">

**Author:** [@contejuz](https://discourse.julialang.org/u/contejuz)\
**Replies:** 0\
**Last updated:** [March 22, 2025, 1:47am UTC](https://discourse.julialang.org/t/cannot-recreate-jumpprocess-example-in-catalyst/127248 "2025-03-22T01:47:02Z")

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I’ve been using Catalyst successfully for the past few weeks. It’s pretty great! However, I recently tried to update PlutoUI from 0.7.14 to 0.7.51 (not sure why such an old version was installed). I then updated all my p…

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## [Reinterpret vector of mixed-type tuples](https://discourse.julialang.org/t/reinterpret-vector-of-mixed-type-tuples/127230)

<div class="topic-metadata">

**Author:** [@hhaensel](https://discourse.julialang.org/u/hhaensel)\
**Replies:** 4\
**Last updated:** [March 21, 2025, 10:52pm UTC](https://discourse.julialang.org/t/reinterpret-vector-of-mixed-type-tuples/127230 "2025-03-21T22:52:36Z")

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I want to reinterpret a vector of mixed-type tuples as a vector of UInt8, however, I receive an error: b = reinterpret(UInt8, Tuple{UInt8, UInt32}\[(1, 2)\]); b\[1\] This is very close to the docs example of reinterpret, w…

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