# Latest

**URL:** https://discourse.julialang.org/latest.md?page=497

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

**Page:** 498

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## [Time normalisation results in \`nothing\` gradients of ODE solutions](https://discourse.julialang.org/t/time-normalisation-results-in-nothing-gradients-of-ode-solutions/109353)

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**Author:** [@ablaom](https://discourse.julialang.org/u/ablaom)\
**Replies:** 5\
**Last updated:** [January 30, 2024, 11:22pm UTC](https://discourse.julialang.org/t/time-normalisation-results-in-nothing-gradients-of-ode-solutions/109353 "2024-01-30T23:22:04Z")

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The following defines the simple one-dimensional ode dx\_dt = -ωx, and a function x(ω, t) to solve it. Fixing t=T, I can readily differentiate x(ω, t) with respect to ω: using DifferentialEquations using SciMLSensitivity…

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## [Historical simulation in SDDP.jl](https://discourse.julialang.org/t/historical-simulation-in-sddp-jl/109473)

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**Author:** [@Sorooshsa](https://discourse.julialang.org/u/Sorooshsa)\
**Replies:** 3\
**Last updated:** [January 30, 2024, 10:01pm UTC](https://discourse.julialang.org/t/historical-simulation-in-sddp-jl/109473 "2024-01-30T22:01:33Z")

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Hi, I did simulation in SDDP.jl using historical data. It works; however, I could not retrieve the optimal solutions anymore by simply putting \[:variable\] as an argument in SDDP.simulate. What should we do in historica…

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## [Will unprecised float printing affect my optimization solving time?](https://discourse.julialang.org/t/will-unprecised-float-printing-affect-my-optimization-solving-time/109456)

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**Author:** [@K5Julien](https://discourse.julialang.org/u/K5Julien)\
**Replies:** 2\
**Last updated:** [January 30, 2024, 8:04pm UTC](https://discourse.julialang.org/t/will-unprecised-float-printing-affect-my-optimization-solving-time/109456 "2024-01-30T20:04:26Z")

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I have a JuMP model and when I show my objective function, i.e.: @show objective\_function(model) objective\_function(model) = -0.17258400000000138 x\[1,1\] - 0.03807000000000031 x\[2,1\] - 0.07106400000000057 x\[3,1\] - 0.073…

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## [Introduction to Julia for Data Science Short course @ MIT, January 16-19, 2024](https://discourse.julialang.org/t/introduction-to-julia-for-data-science-short-course-mit-january-16-19-2024/108466)

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**Author:** [@pszufe](https://discourse.julialang.org/u/pszufe)\
**Replies:** 10\
**Last updated:** [January 30, 2024, 6:38pm UTC](https://discourse.julialang.org/t/introduction-to-julia-for-data-science-short-course-mit-january-16-19-2024/108466 "2024-01-30T18:38:02Z")

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There will by a short 4-day Julia course at the MIT campus in Boston “Introduction to Julia for Data Science” - this is a for-credit class at MIT Mathematics (IAP 2024 Classes). The course instructors have experience bo…

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## [JuliaCon 2024 Childcare and Travel Grant Announcements](https://discourse.julialang.org/t/juliacon-2024-childcare-and-travel-grant-announcements/109463)

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**Author:** [@rayegun](https://discourse.julialang.org/u/rayegun)\
**Replies:** 0\
**Last updated:** [January 30, 2024, 5:44pm UTC](https://discourse.julialang.org/t/juliacon-2024-childcare-and-travel-grant-announcements/109463 "2024-01-30T17:44:06Z")

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Hey folks! As the CfP deadline approaches we’d like to make two brief announcements from the DEI committee @ JuliaCon 2024. The first is an update on travel grants and the application process: The second update is …

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## [Defining a function that modifies its argument in place defines a new function instead](https://discourse.julialang.org/t/defining-a-function-that-modifies-its-argument-in-place-defines-a-new-function-instead/109462)

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**Author:** [@keynescoefen](https://discourse.julialang.org/u/keynescoefen)\
**Replies:** 2\
**Last updated:** [January 30, 2024, 5:42pm UTC](https://discourse.julialang.org/t/defining-a-function-that-modifies-its-argument-in-place-defines-a-new-function-instead/109462 "2024-01-30T17:42:33Z")

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Hello! I have the following function using SpecialFunctions function CDFFoldedNormal(x,μ,σ) #follow the example: https://en.wikipedia.org/wiki/Folded\_normal\_distribution #Note that the folded normal is NOT the h…

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## [How to update CMake version in BinaryBuilder's wizard](https://discourse.julialang.org/t/how-to-update-cmake-version-in-binarybuilders-wizard/109461)

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**Author:** [@PaulVirally](https://discourse.julialang.org/u/PaulVirally)\
**Replies:** 3\
**Last updated:** [January 30, 2024, 5:40pm UTC](https://discourse.julialang.org/t/how-to-update-cmake-version-in-binarybuilders-wizard/109461 "2024-01-30T17:40:11Z")

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I’ve been trying to build a package using BinaryBuilder. My package has a binary dependency that can be built with CMake. I need CMake version 3.18 because it has some CUDA definitions, but the CMake binary that I can us…

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## [Issues with Convergence in Differential Equation Solver Using Dual Numbers](https://discourse.julialang.org/t/issues-with-convergence-in-differential-equation-solver-using-dual-numbers/108871)

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**Author:** [@vivekag7](https://discourse.julialang.org/u/vivekag7)\
**Replies:** 7\
**Last updated:** [January 30, 2024, 5:32pm UTC](https://discourse.julialang.org/t/issues-with-convergence-in-differential-equation-solver-using-dual-numbers/108871 "2024-01-30T17:32:10Z")

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Hello Julia Community, I’m currently working on a differential equation problem related to ice flow modeling and encountering some issues with convergence when using Dual numbers. The problem converges as expected with F…

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## [How to implement Lyons’ Differentiator](https://discourse.julialang.org/t/how-to-implement-lyons-differentiator/109438)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 5\
**Last updated:** [January 30, 2024, 5:28pm UTC](https://discourse.julialang.org/t/how-to-implement-lyons-differentiator/109438 "2024-01-30T17:28:19Z")

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Hello, I am trying to implement a discrete time differentiator, Lyons’ Differentiator type two, see: Design of a Discrete-Time Differentiator | Wireless Pi It has five coefficients. How would you implement that? This …

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## [Functors instead of arrays, matrices etc](https://discourse.julialang.org/t/functors-instead-of-arrays-matrices-etc/109282)

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**Author:** [@Enlil50](https://discourse.julialang.org/u/Enlil50)\
**Replies:** 22\
**Last updated:** [January 30, 2024, 4:24pm UTC](https://discourse.julialang.org/t/functors-instead-of-arrays-matrices-etc/109282 "2024-01-30T16:24:12Z")

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So, there is this C++ eigen feature which I really like: CWiseNullaryOp. To sum it up, you can write a functor, which stores some values and returns some algorithms, and use this as a matrix. This permits you to not st…

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## [CUDA race conditions](https://discourse.julialang.org/t/cuda-race-conditions/109458)

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**Author:** [@trasor](https://discourse.julialang.org/u/trasor)\
**Replies:** 0\
**Last updated:** [January 30, 2024, 4:21pm UTC](https://discourse.julialang.org/t/cuda-race-conditions/109458 "2024-01-30T16:21:49Z")

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Hi together, i try to paralize some of my code with Cuda kernels, but somehow produced race conditions: The kernel looks somewhat like: function updateB!(inputs) x = threadIdx().x + (blockIdx().x-1) \* blockDim().x i…

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## [Large amount of memory allocation when using autodiff and IPNewton](https://discourse.julialang.org/t/large-amount-of-memory-allocation-when-using-autodiff-and-ipnewton/109451)

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**Author:** [@TimOb](https://discourse.julialang.org/u/TimOb)\
**Replies:** 1\
**Last updated:** [January 30, 2024, 4:02pm UTC](https://discourse.julialang.org/t/large-amount-of-memory-allocation-when-using-autodiff-and-ipnewton/109451 "2024-01-30T16:02:37Z")

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Hi all, I’m new to Julia and have been working on a model which essentially is a long loop over optimisation problems: for state = 1:n x0 = ones(5)/2; fun1(x) = -hh\_utility(x, state)\[1\]; …

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## [Computational Meatballs](https://discourse.julialang.org/t/computational-meatballs/109430)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 9\
**Last updated:** [January 30, 2024, 3:42pm UTC](https://discourse.julialang.org/t/computational-meatballs/109430 "2024-01-30T15:42:26Z")

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A couple of years ago, I worked through the wonderful Computational Thinking MIT course. In the spirit of that class, I put together a (quite goofy) Pluto notebook yesterday to resolve a question that I had. I was prepa…

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## [Upper boundary for dispatch in Julia](https://discourse.julialang.org/t/upper-boundary-for-dispatch-in-julia/109405)

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**Author:** [@BBReactionHooper](https://discourse.julialang.org/u/BBReactionHooper)\
**Replies:** 15\
**Last updated:** [January 30, 2024, 3:30pm UTC](https://discourse.julialang.org/t/upper-boundary-for-dispatch-in-julia/109405 "2024-01-30T15:30:14Z")

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Hi fellows, I have a function, which can return five different types according to some conditions. Julia seems to have a problem with type-inference. I created a small example with a similar problem. We create a random …

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## [Snap breaks Julia on Ubuntu](https://discourse.julialang.org/t/snap-breaks-julia-on-ubuntu/109452)

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**Author:** [@sullivan](https://discourse.julialang.org/u/sullivan)\
**Replies:** 3\
**Last updated:** [January 30, 2024, 3:08pm UTC](https://discourse.julialang.org/t/snap-breaks-julia-on-ubuntu/109452 "2024-01-30T15:08:58Z")

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Running julia via snap on Ubuntu 22.04. My user’s files are an nfs mount. After adding the directories to apparmor home.d, we are able to run Julia in the user’s home directory. But not in any subdirectories. Does anyon…

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## [Fresh Julia/PyPlot install errors with \_imaging: the specified module could not be found](https://discourse.julialang.org/t/fresh-julia-pyplot-install-errors-with-imaging-the-specified-module-could-not-be-found/109311)

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**Author:** [@alkoedl](https://discourse.julialang.org/u/alkoedl)\
**Replies:** 4\
**Last updated:** [January 30, 2024, 12:32pm UTC](https://discourse.julialang.org/t/fresh-julia-pyplot-install-errors-with-imaging-the-specified-module-could-not-be-found/109311 "2024-01-30T12:32:57Z")

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After a long time with a perfectly well working PyPlot I today had to install Julia and PyPlot from scratch on a new computer. Adding PyPlot and building Conda/PyCall works. Upon “using PyPlot” conda/matplotlib are insta…

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## [What are active scratchspaces and how to manage them?](https://discourse.julialang.org/t/what-are-active-scratchspaces-and-how-to-manage-them/109445)

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**Author:** [@homocomputeris](https://discourse.julialang.org/u/homocomputeris)\
**Replies:** 1\
**Last updated:** [January 30, 2024, 12:43pm UTC](https://discourse.julialang.org/t/what-are-active-scratchspaces-and-how-to-manage-them/109445 "2024-01-30T12:43:19Z")

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Pkg.jl outputs pkg\> gc Active manifest files: 8 found Active artifact files: 121 found Active scratchspaces: 3 found Deleted no artifacts, repos, packages or scratchspaces The docs do not have an…

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## [Improving model formulation](https://discourse.julialang.org/t/improving-model-formulation/109252)

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**Author:** [@Lemma](https://discourse.julialang.org/u/Lemma)\
**Replies:** 10\
**Last updated:** [January 30, 2024, 11:14am UTC](https://discourse.julialang.org/t/improving-model-formulation/109252 "2024-01-30T11:14:30Z")

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I’m currently working on a sales optimization problem using JuMP in Julia. The challenge involves representing the total sales value under specific constraints. However, my current approach leads to bilinear terms, which…

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## [Stop JuMP optimization when gap doesn't improve enough](https://discourse.julialang.org/t/stop-jump-optimization-when-gap-doesnt-improve-enough/109437)

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**Author:** [@K5Julien](https://discourse.julialang.org/u/K5Julien)\
**Replies:** 2\
**Last updated:** [January 30, 2024, 10:45am UTC](https://discourse.julialang.org/t/stop-jump-optimization-when-gap-doesnt-improve-enough/109437 "2024-01-30T10:45:38Z")

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Suppose that I have a time limit of one day with JuMP and CPLEX: using JuMP, CPLEX, Dates set\_optimizer\_attributes(model, "CPX\_PARAM\_TILIM" =\> Dates.value(Second(Day(1))) # CPU limit in seconds Can I also have another…

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## [Multivariate polynomial with symbolic values](https://discourse.julialang.org/t/multivariate-polynomial-with-symbolic-values/109345)

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**Author:** [@hugopottinger](https://discourse.julialang.org/u/hugopottinger)\
**Replies:** 3\
**Last updated:** [January 30, 2024, 10:21am UTC](https://discourse.julialang.org/t/multivariate-polynomial-with-symbolic-values/109345 "2024-01-30T10:21:42Z")

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For a multivariate polynomial with symbolic coefficients such as p = ax + bx^2y + cx\*y I require in my code to be able to use functions similar to those in MultivariatePolynomials such as length(p), degree(p,x), coeffi…

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## [Unexpected allocation](https://discourse.julialang.org/t/unexpected-allocation/109393)

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**Author:** [@abraunst](https://discourse.julialang.org/u/abraunst)\
**Replies:** 7\
**Last updated:** [January 30, 2024, 8:45am UTC](https://discourse.julialang.org/t/unexpected-allocation/109393 "2024-01-30T08:45:33Z")

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I’m trying to write an iteration for my type. The iteration needs to keep a Vector and an Int in its state. I cannot get rid of an allocation. I condensed the problem into the following MWE: function iter((i,v)) v\[…

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## [\[ANN\] ExpressionExplorer.jl and PlutoDependencyExplorer.jl – the internal reactivity algorithm of Pluto!](https://discourse.julialang.org/t/ann-expressionexplorer-jl-and-plutodependencyexplorer-jl-the-internal-reactivity-algorithm-of-pluto/109068)

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**Author:** [@fonsp](https://discourse.julialang.org/u/fonsp)\
**Replies:** 5\
**Last updated:** [January 30, 2024, 7:46am UTC](https://discourse.julialang.org/t/ann-expressionexplorer-jl-and-plutodependencyexplorer-jl-the-internal-reactivity-algorithm-of-pluto/109068 "2024-01-30T07:46:11Z")

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We just released two new packages! :tada: ExpressionExplorer.jl (EE) – find all variables assigned and referenced in a piece of code. PlutoDependencyExplorer.jl (PDE) – sort a list of codes by execution order Both pac…

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## [Strategy help](https://discourse.julialang.org/t/strategy-help/109370)

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**Author:** [@mpeters2](https://discourse.julialang.org/u/mpeters2)\
**Replies:** 23\
**Last updated:** [January 30, 2024, 6:42am UTC](https://discourse.julialang.org/t/strategy-help/109370 "2024-01-30T06:42:26Z")

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I’d looking for some input on the best way to tackle this. Right now I have a struct that looks something like this: mutable struct Line win::Window startPoint::Vector{Int64} endPoint::Vector{Int64} li…

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## [Maximum does not work on UInt](https://discourse.julialang.org/t/maximum-does-not-work-on-uint/109424)

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**Author:** [@crinders](https://discourse.julialang.org/u/crinders)\
**Replies:** 7\
**Last updated:** [January 30, 2024, 6:24am UTC](https://discourse.julialang.org/t/maximum-does-not-work-on-uint/109424 "2024-01-30T06:24:59Z")

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a = convert(UInt, 1) b= convert(UInt, 2) maximum(a, b) fails with ERROR: MethodError: objects of type UInt64 are not callable Maybe you forgot to use an operator such as \*, ^, %, / etc. ? Stacktrace: \[1\] mapreduce\_fir…

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## [Struggling to define Jump constraints for modified TSP in a programmatic way](https://discourse.julialang.org/t/struggling-to-define-jump-constraints-for-modified-tsp-in-a-programmatic-way/106346)

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**Author:** [@Lee\_Phillips](https://discourse.julialang.org/u/Lee_Phillips)\
**Replies:** 4\
**Last updated:** [January 30, 2024, 2:55am UTC](https://discourse.julialang.org/t/struggling-to-define-jump-constraints-for-modified-tsp-in-a-programmatic-way/106346 "2024-01-30T02:55:07Z")

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Hey All I’m working on a traveling salesman like problem with a few additional constraints and I’m using the JUMP package. One of the constraints is that certain nodes on the graph need to be performed sequentially Ho…

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## [Custom Complex number type for specific Real type](https://discourse.julialang.org/t/custom-complex-number-type-for-specific-real-type/109374)

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**Author:** [@mattsignorelli](https://discourse.julialang.org/u/mattsignorelli)\
**Replies:** 9\
**Last updated:** [January 30, 2024, 12:40am UTC](https://discourse.julialang.org/t/custom-complex-number-type-for-specific-real-type/109374 "2024-01-30T00:40:26Z")

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Hello! I have implemented a Julia interface to a C library for a special number type. The real and complex types are handled internally by the C library, so I have Julia wrapper structs that are basically MyNumber and Co…

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## [\[ANN\] ComputerVisionTutorials.jl - Tutorial "Package" for Artificial Intelligence](https://discourse.julialang.org/t/ann-computervisiontutorials-jl-tutorial-package-for-artificial-intelligence/109167)

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**Author:** [@Dale\_James\_Black](https://discourse.julialang.org/u/Dale_James_Black)\
**Replies:** 5\
**Last updated:** [January 29, 2024, 10:27pm UTC](https://discourse.julialang.org/t/ann-computervisiontutorials-jl-tutorial-package-for-artificial-intelligence/109167 "2024-01-29T22:27:49Z")

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Introduction I’m currently developing a suite of deep learning computer vision tutorials, with a special emphasis on medical imaging. These tutorials are designed as interactive Pluto notebooks that you can use direct…

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## [SBMLToolkit and Catalyst Warnings](https://discourse.julialang.org/t/sbmltoolkit-and-catalyst-warnings/107533)

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**Author:** [@Nick1](https://discourse.julialang.org/u/Nick1)\
**Replies:** 3\
**Last updated:** [January 29, 2024, 10:14pm UTC](https://discourse.julialang.org/t/sbmltoolkit-and-catalyst-warnings/107533 "2024-01-29T22:14:12Z")

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I am importing an SBML file without a problem but I got the following warnings: Warning: Stoichiometries of SpeciesReferences are not defined. Setting to 1. WARNING: both Symbolics and ModelingToolkit export “suprem…

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## [Julia installation, Linux](https://discourse.julialang.org/t/julia-installation-linux/109421)

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**Author:** [@Enlil50](https://discourse.julialang.org/u/Enlil50)\
**Replies:** 4\
**Last updated:** [January 29, 2024, 8:10pm UTC](https://discourse.julialang.org/t/julia-installation-linux/109421 "2024-01-29T20:10:31Z")

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I suck installing things. I better write them from scratch. So, I runned the script on the Julia site. At the end it said it was successful: Now installing Juliaup Installing Julia 1.10.0+0.x64.linux.gnu Configured the…

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## [Plans for static compiled binaries?](https://discourse.julialang.org/t/plans-for-static-compiled-binaries/107413)

<div class="topic-metadata">

**Author:** [@Mateusz\_K](https://discourse.julialang.org/u/Mateusz_K)\
**Replies:** 13\
**Last updated:** [January 29, 2024, 7:44pm UTC](https://discourse.julialang.org/t/plans-for-static-compiled-binaries/107413 "2024-01-29T19:44:43Z")

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Dear Julia Developers, Is static compilation currently on the development roadmap for Julia? Any information on its progress or plans would be appreciated. I am asking this because my use case is typically delivering b…

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