# Latest

**URL:** https://discourse.julialang.org/latest.md?page=217

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

**Page:** 218

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## [Difficulty in using JuMP with Complex Functions](https://discourse.julialang.org/t/difficulty-in-using-jump-with-complex-functions/126045)

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**Author:** [@MechRob](https://discourse.julialang.org/u/MechRob)\
**Replies:** 3\
**Last updated:** [February 18, 2025, 11:42pm UTC](https://discourse.julialang.org/t/difficulty-in-using-jump-with-complex-functions/126045 "2025-02-18T23:42:04Z")

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I am trying to create an optimization problem with JuMP. In order to create the constraints I have a function, which I generated its elements with Symbolics. When I pass numerical values, I can calculate the terms in ten…

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## [Enums to string & string to enum: a simple guide to use enums & strings](https://discourse.julialang.org/t/enums-to-string-string-to-enum-a-simple-guide-to-use-enums-strings/126044)

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**Author:** [@0nyr](https://discourse.julialang.org/u/0nyr)\
**Replies:** 0\
**Last updated:** [February 18, 2025, 8:57pm UTC](https://discourse.julialang.org/t/enums-to-string-string-to-enum-a-simple-guide-to-use-enums-strings/126044 "2025-02-18T20:57:50Z")

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Practical guide to Julia Enums ↔ Strings Well, I do this post for the me of the past that spent way to much time on understanding Enums and how to deal with Symbols, Strings and Enums. Coming from Rust, dealing with Juli…

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## [How to write inline math variables, equations in Markdown inside Pluto?](https://discourse.julialang.org/t/how-to-write-inline-math-variables-equations-in-markdown-inside-pluto/126041)

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**Author:** [@ghoshr](https://discourse.julialang.org/u/ghoshr)\
**Replies:** 2\
**Last updated:** [February 18, 2025, 7:40pm UTC](https://discourse.julialang.org/t/how-to-write-inline-math-variables-equations-in-markdown-inside-pluto/126041 "2025-02-18T19:40:06Z")

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I am trying to write some mathematical variables and equations inline in Markdown in Pluto. I am trying to write \\dfrac{a}{b} = c and x inside other sentences. And not a/b = c and x. This is how I did it here, and how I …

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## [FFMPEG error when using @animate in Julia: "Output file #0 does not contain any stream"](https://discourse.julialang.org/t/ffmpeg-error-when-using-animate-in-julia-output-file-0-does-not-contain-any-stream/125919)

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**Author:** [@Sarah\_Groves](https://discourse.julialang.org/u/Sarah_Groves)\
**Replies:** 4\
**Last updated:** [February 18, 2025, 7:15pm UTC](https://discourse.julialang.org/t/ffmpeg-error-when-using-animate-in-julia-output-file-0-does-not-contain-any-stream/125919 "2025-02-18T19:15:59Z")

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I am trying to run the example code at Animations · Plots : using Plots @userplot CirclePlot @recipe function f(cp::CirclePlot) x, y, i = cp.args n = length(x) inds = circshift(1:n, 1 - i) linewidth --\> …

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## [Parallel computation to speed up for loops](https://discourse.julialang.org/t/parallel-computation-to-speed-up-for-loops/126006)

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**Author:** [@AP9](https://discourse.julialang.org/u/AP9)\
**Replies:** 3\
**Last updated:** [February 18, 2025, 7:00pm UTC](https://discourse.julialang.org/t/parallel-computation-to-speed-up-for-loops/126006 "2025-02-18T19:00:02Z")

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I am computing the Lyapunov exponents in 2D for the system below, by doing a for loop over two parameters (ωA, A) and it takes a really long time. using Parameters, ChaosTools, DifferentialEquations, Distributed, Shared…

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## [Copy on write?](https://discourse.julialang.org/t/copy-on-write/126021)

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**Author:** [@iago-lito](https://discourse.julialang.org/u/iago-lito)\
**Replies:** 2\
**Last updated:** [February 18, 2025, 5:19pm UTC](https://discourse.julialang.org/t/copy-on-write/126021 "2025-02-18T17:19:17Z")

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Hello Julia, I need copy-on-write behaviour to protect fields of the large values I’m handing out to my users from cluttering their memory with useless copies. Is there such thing as a julia Cow{T} akin to rust’s Cow\<T\>…

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## [Documenter.jl not including any definitions and then complaining that they're missing](https://discourse.julialang.org/t/documenter-jl-not-including-any-definitions-and-then-complaining-that-theyre-missing/124644)

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**Author:** [@Mark\_Nahabedian](https://discourse.julialang.org/u/Mark_Nahabedian)\
**Replies:** 1\
**Last updated:** [February 18, 2025, 3:34pm UTC](https://discourse.julialang.org/t/documenter-jl-not-including-any-definitions-and-then-complaining-that-theyre-missing/124644 "2025-02-18T15:34:00Z")

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One of my projects, GitHub - MarkNahabedian/Rete.jl: An inplementation of the Rete knowledge based system shell., is failing its documentation build both in its CI GitHub action and locally. This documentetion used to…

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## [Where NLPModels.jl stands in comparition to JuMP?](https://discourse.julialang.org/t/where-nlpmodels-jl-stands-in-comparition-to-jump/126033)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 1\
**Last updated:** [February 18, 2025, 3:32pm UTC](https://discourse.julialang.org/t/where-nlpmodels-jl-stands-in-comparition-to-jump/126033 "2025-02-18T15:32:56Z")

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I have just discovered NLPModels.jl. How does it stand compared to JuMP ? I even understood there is a package to translate one “model format” (??) to the other, but I don’t have quite clear how the two packages positio…

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## [Type-stable reading from a file](https://discourse.julialang.org/t/type-stable-reading-from-a-file/125797)

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**Author:** [@VictorSeven](https://discourse.julialang.org/u/VictorSeven)\
**Replies:** 14\
**Last updated:** [February 18, 2025, 2:44pm UTC](https://discourse.julialang.org/t/type-stable-reading-from-a-file/125797 "2025-02-18T14:44:30Z")

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I was analysing some code today and I am unable to read information from a simple file while keeping type stability. I would like to pass the results to functions that have to be very optimized, so I believe this is an i…

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## [Training Universal PINNs using NeuralPDE?](https://discourse.julialang.org/t/training-universal-pinns-using-neuralpde/125948)

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**Author:** [@John\_Nardini](https://discourse.julialang.org/u/John_Nardini)\
**Replies:** 4\
**Last updated:** [February 18, 2025, 2:34pm UTC](https://discourse.julialang.org/t/training-universal-pinns-using-neuralpde/125948 "2025-02-18T14:34:44Z")

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I am interested Universal PINNs (UPINNs) to describe some data. UPINNs are similar to a PINN, but we assume that the underlying DE model has known and unknown dynamics: \\dfrac{d\\vec{u}}{dt} = F\_{known}(\\vec{u}) + F\_{unk…

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## [Julia hangs while importing package when monitor is not attached](https://discourse.julialang.org/t/julia-hangs-while-importing-package-when-monitor-is-not-attached/125996)

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**Author:** [@johnomotani](https://discourse.julialang.org/u/johnomotani)\
**Replies:** 3\
**Last updated:** [February 17, 2025, 7:20pm UTC](https://discourse.julialang.org/t/julia-hangs-while-importing-package-when-monitor-is-not-attached/125996 "2025-02-17T19:20:20Z")

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I’m struggling to understand where to even start debugging this one! I have a workstation that I usually only access over the network, so it does not normally have a monitor or keyboard/mouse attached. Some time between …

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## [How to draw the lines connecting the subplots](https://discourse.julialang.org/t/how-to-draw-the-lines-connecting-the-subplots/124540)

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**Author:** [@Gregstrq](https://discourse.julialang.org/u/Gregstrq)\
**Replies:** 3\
**Last updated:** [February 18, 2025, 2:12pm UTC](https://discourse.julialang.org/t/how-to-draw-the-lines-connecting-the-subplots/124540 "2025-02-18T14:12:40Z")

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I would like to draw the lines on top of a large composite plot constructed from several subplots using layout. Specifically, I would like to draw the lines in the gap between the two plots to indicate that one of the s…

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## [I get a warning when i use Upsample layer with AMDGPU](https://discourse.julialang.org/t/i-get-a-warning-when-i-use-upsample-layer-with-amdgpu/112728)

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**Author:** [@Radu\_Mihai\_Diaconu](https://discourse.julialang.org/u/Radu_Mihai_Diaconu)\
**Replies:** 1\
**Last updated:** [February 18, 2025, 11:00am UTC](https://discourse.julialang.org/t/i-get-a-warning-when-i-use-upsample-layer-with-amdgpu/112728 "2025-02-18T11:00:35Z")

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Hello guys so i have this code using Flux: Upsample noise = 0.5f0 + 0.001f0 .+ AMDGPU.randn(Float32, 32, 32, 1, 1) layer1 = Upsample(:bilinear, size=(64, 64, 1, 1)) |\> gpu layer1(noise) any reason for me getting thi…

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## [Uahgi - an experimential typesetting engine/compiler generating PDF document](https://discourse.julialang.org/t/uahgi-an-experimential-typesetting-engine-compiler-generating-pdf-document/125967)

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**Author:** [@Yoxem](https://discourse.julialang.org/u/Yoxem)\
**Replies:** 8\
**Last updated:** [February 18, 2025, 10:51am UTC](https://discourse.julialang.org/t/uahgi-an-experimential-typesetting-engine-compiler-generating-pdf-document/125967 "2025-02-18T10:51:08Z")

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Announcing uahgi, which is an experimental typesetting engine/compiler like “the little plainTeX” (but actually its functions are not as rich as plainTeX). It’s a practice of the Knuth-liang hyphenation algorithm and a …

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## [Multithreading doesn't improve the performance](https://discourse.julialang.org/t/multithreading-doesnt-improve-the-performance/126020)

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**Author:** [@wq-123](https://discourse.julialang.org/u/wq-123)\
**Replies:** 6\
**Last updated:** [February 18, 2025, 10:27am UTC](https://discourse.julialang.org/t/multithreading-doesnt-improve-the-performance/126020 "2025-02-18T10:27:48Z")

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Hello, I’m trying to calculate my for-loop with multithreading. But there’s no increase in computing speed. Here’s the struct of my code. B = \[\[\[zeros(ComplexF64,1,6) for a in 1:3\] for \_ in 1:Nw\] for z in 1:Threads.nthr…

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## [Distributed Data Parallel training with 2 GPUs fails with Flux.jl on AMD GPUs](https://discourse.julialang.org/t/distributed-data-parallel-training-with-2-gpus-fails-with-flux-jl-on-amd-gpus/125993)

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**Author:** [@Alexander-Barth](https://discourse.julialang.org/u/Alexander-Barth)\
**Replies:** 7\
**Last updated:** [February 18, 2025, 8:41am UTC](https://discourse.julialang.org/t/distributed-data-parallel-training-with-2-gpus-fails-with-flux-jl-on-amd-gpus/125993 "2025-02-18T08:41:29Z")

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I am using Flux (with this PR Fix missing imports in FluxMPIExt by Alexander-Barth · Pull Request #2589 · FluxML/Flux.jl · GitHub to fix some MPI related imports) on two AMD GPUs with Distributed Data Parallel (DDP). Ho…

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## [OR-Tools for JuMP](https://discourse.julialang.org/t/or-tools-for-jump/106171)

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**Author:** [@Stuart\_Rogers](https://discourse.julialang.org/u/Stuart_Rogers)\
**Replies:** 6\
**Last updated:** [February 18, 2025, 7:04am UTC](https://discourse.julialang.org/t/or-tools-for-jump/106171 "2025-02-18T07:04:54Z")

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Are there plans to add the solvers in OR-Tools to JuMP? OR-Tools has 2 LP solvers, PDLP and GLOP, and a constraint programming solver, CP-SAT, which solves integer linear programs (no continuous variables) and more gener…

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## [Average multiple evaluations of the same function](https://discourse.julialang.org/t/average-multiple-evaluations-of-the-same-function/126009)

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**Author:** [@ignace](https://discourse.julialang.org/u/ignace)\
**Replies:** 2\
**Last updated:** [February 17, 2025, 9:09pm UTC](https://discourse.julialang.org/t/average-multiple-evaluations-of-the-same-function/126009 "2025-02-17T21:09:41Z")

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Suppose we have a function f(input) that transforms input (a long list of input arguments) into an output (a long tuple), depending on some (hidden) random values. A very minimalist example is the randn function. Is th…

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## [Configuration file directories](https://discourse.julialang.org/t/configuration-file-directories/125925)

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**Author:** [@phma](https://discourse.julialang.org/u/phma)\
**Replies:** 4\
**Last updated:** [February 18, 2025, 5:11am UTC](https://discourse.julialang.org/t/configuration-file-directories/125925 "2025-02-18T05:11:49Z")

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Is there a function that returns the list of directories to look for configuration files in? For example, my home directory is /home/phma/, so it should return \["/etc/","/home/phma/.local/etc/"\] or something like that.

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## [\[ANN\] A database of quantum graph states equivalent under local operations](https://discourse.julialang.org/t/ann-a-database-of-quantum-graph-states-equivalent-under-local-operations/126013)

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**Author:** [@Krastanov](https://discourse.julialang.org/u/Krastanov)\
**Replies:** 0\
**Last updated:** [February 18, 2025, 3:10am UTC](https://discourse.julialang.org/t/ann-a-database-of-quantum-graph-states-equivalent-under-local-operations/126013 "2025-02-18T03:10:27Z")

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Quantum graph states are a useful tool to study quantum entanglement and a resource in networking and computation. Knowing whether two graph states are equivalent under local operations is quite useful when studying how …

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## [Does Mmap.sync! from disk to array, array to disk, or both?](https://discourse.julialang.org/t/does-mmap-sync-from-disk-to-array-array-to-disk-or-both/126012)

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**Author:** [@ilanggear](https://discourse.julialang.org/u/ilanggear)\
**Replies:** 2\
**Last updated:** [February 17, 2025, 11:37pm UTC](https://discourse.julialang.org/t/does-mmap-sync-from-disk-to-array-array-to-disk-or-both/126012 "2025-02-17T23:37:30Z")

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I’m trying to understand how to use memory mapping. Here’s a bit of code that represents what I’d like to do. I want to write to an array, and have the changes propagated to a file. Is that not how Mmap works? The co…

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## [How to spawn persistent threads and reuse them?](https://discourse.julialang.org/t/how-to-spawn-persistent-threads-and-reuse-them/126002)

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**Author:** [@Leo\_I](https://discourse.julialang.org/u/Leo_I)\
**Replies:** 16\
**Last updated:** [February 17, 2025, 9:50pm UTC](https://discourse.julialang.org/t/how-to-spawn-persistent-threads-and-reuse-them/126002 "2025-02-17T21:50:25Z")

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Let nt=nthreads(). I have a loop for k=1:n compute!(k, ...) end that I wish to parallelize. I did so as for k0=1:nt:n k1 = min(k0+nt-1,n); @threads for k=k0:k1 compute!(k, ...) end compress\_results!(k0…

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## [Hessian preparation using DifferentationInterface and Mooncake throws a stackoverflow error](https://discourse.julialang.org/t/hessian-preparation-using-differentationinterface-and-mooncake-throws-a-stackoverflow-error/125946)

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**Author:** [@Gattu\_Mytraya](https://discourse.julialang.org/u/Gattu_Mytraya)\
**Replies:** 9\
**Last updated:** [February 17, 2025, 9:47pm UTC](https://discourse.julialang.org/t/hessian-preparation-using-differentationinterface-and-mooncake-throws-a-stackoverflow-error/125946 "2025-02-17T21:47:24Z")

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Hi, I am trying to calculate the hessian of a function using DifferentitationInterface.jl with Mooncake as the backend. The calculation of the jacobian this way is very fast - both in the preparation stage and the actua…

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## [Porting Julia to new platforms](https://discourse.julialang.org/t/porting-julia-to-new-platforms/122698)

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**Author:** [@phma](https://discourse.julialang.org/u/phma)\
**Replies:** 17\
**Last updated:** [February 17, 2025, 8:59pm UTC](https://discourse.julialang.org/t/porting-julia-to-new-platforms/122698 "2025-02-17T20:59:57Z")

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I cloned the Julia repo to my SmartOS box, intending to build it. I found out that: it has a Makefile, not a configure script or a CMakeLists.txt file or the like; it failed to build; somewhere in the source code, ther…

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## [\[ANN\] TumorGrowth.jl: Tool for calibrating tumor growth models, including neural ODEs](https://discourse.julialang.org/t/ann-tumorgrowth-jl-tool-for-calibrating-tumor-growth-models-including-neural-odes/126008)

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**Author:** [@ablaom](https://discourse.julialang.org/u/ablaom)\
**Replies:** 1\
**Last updated:** [February 17, 2025, 8:45pm UTC](https://discourse.julialang.org/t/ann-tumorgrowth-jl-tool-for-calibrating-tumor-growth-models-including-neural-odes/126008 "2025-02-17T20:45:47Z")

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TumorGrowth.jl is a new package providing ODE-based models for predicting the changes in volume of a lesion. In addition to classical models, like Bertalanffy and Gompertz, it includes, as experimental, some neural ODE m…

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## [HDF5 is broken on Windows?](https://discourse.julialang.org/t/hdf5-is-broken-on-windows/125988)

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**Author:** [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Replies:** 2\
**Last updated:** [February 17, 2025, 6:57pm UTC](https://discourse.julialang.org/t/hdf5-is-broken-on-windows/125988 "2025-02-17T18:57:50Z")

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Since yesterday I started to see failures in building GMT in CI (and locally) due to ERROR: LoadError: InitError: could not load library "C:\\Users\\j\\.julia\\artifacts\\a0f65aec92810567654b7ca3b29b0786088806a6\\bin\\libnetcd…

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## [Issue parsing Ipopt\_jll string option when there is blank space in path](https://discourse.julialang.org/t/issue-parsing-ipopt-jll-string-option-when-there-is-blank-space-in-path/125943)

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**Author:** [@KSepetanc](https://discourse.julialang.org/u/KSepetanc)\
**Replies:** 4\
**Last updated:** [February 17, 2025, 6:48pm UTC](https://discourse.julialang.org/t/issue-parsing-ipopt-jll-string-option-when-there-is-blank-space-in-path/125943 "2025-02-17T18:48:14Z")

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The following code does not work when called from path that has blank space. using JuMP, AmplNLWriter, Ipopt\_jll mod = Model(() -\> AmplNLWriter.Optimizer(Ipopt\_jll.amplexe)) set\_attribute(mod, "output\_file", joinpath(@…

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## [Optim.jl and runtime dispatch detected errors](https://discourse.julialang.org/t/optim-jl-and-runtime-dispatch-detected-errors/125981)

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**Author:** [@Miroboru](https://discourse.julialang.org/u/Miroboru)\
**Replies:** 1\
**Last updated:** [February 17, 2025, 6:36pm UTC](https://discourse.julialang.org/t/optim-jl-and-runtime-dispatch-detected-errors/125981 "2025-02-17T18:36:23Z")

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I have a piece of simulation software that makes millions of calls to Optim.optimize during runs. I seemingly have a lot of allocations, so I use JET and tested my code with @report\_opt. The result was a large number of …

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## [Difficulty when differentiating with DifferentiationInterface.jl and Mooncake.jl](https://discourse.julialang.org/t/difficulty-when-differentiating-with-differentiationinterface-jl-and-mooncake-jl/125982)

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**Author:** [@Nikos\_Gianniotis](https://discourse.julialang.org/u/Nikos_Gianniotis)\
**Replies:** 3\
**Last updated:** [February 17, 2025, 5:23pm UTC](https://discourse.julialang.org/t/difficulty-when-differentiating-with-differentiationinterface-jl-and-mooncake-jl/125982 "2025-02-17T17:23:25Z")

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Hello everyone. I am stuck with the following problem for which I have created below a MWE. It concerns automatic differentiation using DifferentiationInterface.jl together with Mooncake.jl. From the error message I get,…

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## [Resizing ODE integrator of type matrix](https://discourse.julialang.org/t/resizing-ode-integrator-of-type-matrix/126000)

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**Author:** [@B4rtel](https://discourse.julialang.org/u/B4rtel)\
**Replies:** 4\
**Last updated:** [February 17, 2025, 5:02pm UTC](https://discourse.julialang.org/t/resizing-ode-integrator-of-type-matrix/126000 "2025-02-17T17:02:42Z")

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I’m trying to resize the integrator in and ODE solved with solve where u is a matrix. I also found a post similar to this (Resizing ODE integrator with matrix or VectorOfArray initial condition) but I want to do it with …

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