# Latest

**URL:** https://discourse.julialang.org/latest.md?page=543

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

**Page:** 544

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## [Row / column major with PythonCall , OpenCV](https://discourse.julialang.org/t/row-column-major-with-pythoncall-opencv/106620)

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**Author:** [@kemu](https://discourse.julialang.org/u/kemu)\
**Replies:** 18\
**Last updated:** [November 29, 2023, 12:15pm UTC](https://discourse.julialang.org/t/row-column-major-with-pythoncall-opencv/106620 "2023-11-29T12:15:27Z")

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row / column major with PythonCall and numpy + OpenCV I am trying to create an image processing program using PythonCall.jl and the Python version of OpenCV. The specification I have in mind now is to create the pixel …

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## [Revise fails to pre-compile](https://discourse.julialang.org/t/revise-fails-to-pre-compile/106884)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 4\
**Last updated:** [November 29, 2023, 10:51am UTC](https://discourse.julialang.org/t/revise-fails-to-pre-compile/106884 "2023-11-29T10:51:14Z")

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This morning I get the following error: julia\> using Revise Precompiling Revise Info Given Revise was explicitly requested, output will be shown live ERROR: LoadError: UndefVarError: \`is\_GotoIfNot\` not defined …

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## [Ideas for Saving Intermediate Results](https://discourse.julialang.org/t/ideas-for-saving-intermediate-results/106724)

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**Author:** [@TI36XPro](https://discourse.julialang.org/u/TI36XPro)\
**Replies:** 7\
**Last updated:** [November 29, 2023, 8:44am UTC](https://discourse.julialang.org/t/ideas-for-saving-intermediate-results/106724 "2023-11-29T08:44:52Z")

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Hello, I’d appreciate any thoughts or feedback on how I could implement the following. I have a long-running simulation (several days) I run on my university’s HPC. Till now I have been saving the results at the end of…

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## [Handling Dates](https://discourse.julialang.org/t/handling-dates/106879)

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**Author:** [@Sourish](https://discourse.julialang.org/u/Sourish)\
**Replies:** 4\
**Last updated:** [November 29, 2023, 8:44am UTC](https://discourse.julialang.org/t/handling-dates/106879 "2023-11-29T08:44:10Z")

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Hi I am trying to convert a string to date with the following code - but giving me some parsing error using Dates df = DateFormat("d-b-y"); dt = Date("28-Feb-99",df) I am getting the following error: ArgumentError: U…

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## [How to execute tasks in parallel in a for loop](https://discourse.julialang.org/t/how-to-execute-tasks-in-parallel-in-a-for-loop/106736)

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**Author:** [@Chamika\_Kasun](https://discourse.julialang.org/u/Chamika_Kasun)\
**Replies:** 27\
**Last updated:** [November 29, 2023, 3:22am UTC](https://discourse.julialang.org/t/how-to-execute-tasks-in-parallel-in-a-for-loop/106736 "2023-11-29T03:22:42Z")

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I’m quite new to Julia programming, and I’m looking for a better way to parallelize the execution of a for loop. Basically, the logic I have in the following code needs to be executed in parallel. data = \[\] …

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## [Lazy read string from iostream?](https://discourse.julialang.org/t/lazy-read-string-from-iostream/106782)

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**Author:** [@ryofurue](https://discourse.julialang.org/u/ryofurue)\
**Replies:** 6\
**Last updated:** [November 29, 2023, 3:15am UTC](https://discourse.julialang.org/t/lazy-read-string-from-iostream/106782 "2023-11-29T03:15:13Z")

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It seems that read(iostream, String) reads the entire file into the memory at once. (Please correct me if I’m mistaken.) I’ve just deduced that from this test code: f = open("tmp.txt", "r") s = read(f, String) typeof(…

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## [Can't take a gradient using Symbolic vector](https://discourse.julialang.org/t/cant-take-a-gradient-using-symbolic-vector/106867)

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**Author:** [@Cade\_Armstrong](https://discourse.julialang.org/u/Cade_Armstrong)\
**Replies:** 9\
**Last updated:** [November 29, 2023, 12:07am UTC](https://discourse.julialang.org/t/cant-take-a-gradient-using-symbolic-vector/106867 "2023-11-29T00:07:30Z")

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I’m running into some trouble when taking a gradient of a symbolic function using a symbolic vector. using Symbolics @variables x\[1:2\] xₒ = \[1;1\] f = (x\[1\] + 2\*x\[2\])^3 f\_fun = build\_function(f, x) vals = eval(f\_fun…

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## [Point Occlusion in 3D Scatter Makie](https://discourse.julialang.org/t/point-occlusion-in-3d-scatter-makie/95413)

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**Author:** [@Jordan\_Cluts](https://discourse.julialang.org/u/Jordan_Cluts)\
**Replies:** 14\
**Last updated:** [November 28, 2023, 10:53pm UTC](https://discourse.julialang.org/t/point-occlusion-in-3d-scatter-makie/95413 "2023-11-28T22:53:03Z")

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When I create a 3D scatter plot in Makie some of the points that are “closer” to the camera are plotted behind points that are further from the camera. This can make the plots harder to interpret. Is there a setting or t…

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## [\[ANN\] MacroModelling.jl: developing and solving DSGE models](https://discourse.julialang.org/t/ann-macromodelling-jl-developing-and-solving-dsge-models/106859)

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**Author:** [@thorek1](https://discourse.julialang.org/u/thorek1)\
**Replies:** 2\
**Last updated:** [November 28, 2023, 7:05pm UTC](https://discourse.julialang.org/t/ann-macromodelling-jl-developing-and-solving-dsge-models/106859 "2023-11-28T19:05:26Z")

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I am happy to announce MacroModelling.jl - a package for developing and solving dynamic stochastic general equilibrium (DSGE) models. The goal of this package is to reduce coding time and speed up model development by p…

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## [Dynamically defining a struct with default values](https://discourse.julialang.org/t/dynamically-defining-a-struct-with-default-values/106855)

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**Author:** [@Titas22](https://discourse.julialang.org/u/Titas22)\
**Replies:** 3\
**Last updated:** [November 28, 2023, 8:09pm UTC](https://discourse.julialang.org/t/dynamically-defining-a-struct-with-default-values/106855 "2023-11-28T20:09:07Z")

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Hi, I would like to be able to define a struct with some default values based on an input Dict. The input is something like this: d = Dict("A"=\>1, "B"=\>2, "C"=\>"x", "D"=\>\[1,2\]) And I would like to define a struct lik…

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## [Accessing the coefficients of a preconditioner](https://discourse.julialang.org/t/accessing-the-coefficients-of-a-preconditioner/106789)

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**Author:** [@Gravlax](https://discourse.julialang.org/u/Gravlax)\
**Replies:** 4\
**Last updated:** [November 28, 2023, 8:04pm UTC](https://discourse.julialang.org/t/accessing-the-coefficients-of-a-preconditioner/106789 "2023-11-28T20:04:25Z")

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Hi all, I would like to access coefficients of a preconditioner constructed using the ILUZero package. ILUZero returns an object of type ::ILU0Precon{Float64, Int64, Float64} which contains a sparse representations of …

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## [Combining Catalyst DSL models and ModelingToolkit explicit ODE models](https://discourse.julialang.org/t/combining-catalyst-dsl-models-and-modelingtoolkit-explicit-ode-models/54418)

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**Author:** [@conradh](https://discourse.julialang.org/u/conradh)\
**Replies:** 18\
**Last updated:** [November 28, 2023, 6:49pm UTC](https://discourse.julialang.org/t/combining-catalyst-dsl-models-and-modelingtoolkit-explicit-ode-models/54418 "2023-11-28T18:49:02Z")

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I’d like to connect a model defined via explicit ODEs using ModelingToolkit.jl with a model defined using the reaction DSL provided by Catalyst.jl. Specifically, I’d like to use an output of my ODE model as a forcing fun…

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## [ANN: DispersionRelations.jl](https://discourse.julialang.org/t/ann-dispersionrelations-jl/104815)

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**Author:** [@Jack\_Coughlin](https://discourse.julialang.org/u/Jack_Coughlin)\
**Replies:** 2\
**Last updated:** [November 28, 2023, 6:32pm UTC](https://discourse.julialang.org/t/ann-dispersionrelations-jl/104815 "2023-11-28T18:32:16Z")

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DispersionRelations.jl This is my first package, a small utility for estimating complex frequencies of exponentially growing or damping phenomena. To illustrate, this package provides a function to estimate the slopes …

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## [Is there any method to get a JuMP model in Latex format?](https://discourse.julialang.org/t/is-there-any-method-to-get-a-jump-model-in-latex-format/106728)

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**Author:** [@Alex\_ricci](https://discourse.julialang.org/u/Alex_ricci)\
**Replies:** 5\
**Last updated:** [November 28, 2023, 5:29pm UTC](https://discourse.julialang.org/t/is-there-any-method-to-get-a-jump-model-in-latex-format/106728 "2023-11-28T17:29:25Z")

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I use JuMP package from julia programming language for modelling optimization problems. To investigate the performance of the model I need to print some of the model constraints. I want to know is there any automatic way…

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## [Fortran-Julia interface for program containing non-c-interoperable derived type](https://discourse.julialang.org/t/fortran-julia-interface-for-program-containing-non-c-interoperable-derived-type/106815)

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**Author:** [@tmph](https://discourse.julialang.org/u/tmph)\
**Replies:** 6\
**Last updated:** [November 28, 2023, 4:59pm UTC](https://discourse.julialang.org/t/fortran-julia-interface-for-program-containing-non-c-interoperable-derived-type/106815 "2023-11-28T16:59:45Z")

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I’m still new to Julia (and this discourse), but couldn’t find the answer to this question anywhere. I have a large Fortran legacy code base which I’m trying to interface with a high-level language. I got something kind…

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## [No syntax highlighting here?](https://discourse.julialang.org/t/no-syntax-highlighting-here/106674)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 14\
**Last updated:** [November 28, 2023, 3:06pm UTC](https://discourse.julialang.org/t/no-syntax-highlighting-here/106674 "2023-11-28T15:06:20Z")

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It is only me, or the site is not highlighting the code now? function test(x) return x + 1 end

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## [HUION Inspiroy 2 tablet driver in Julia](https://discourse.julialang.org/t/huion-inspiroy-2-tablet-driver-in-julia/106752)

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**Author:** [@raman\_kumar](https://discourse.julialang.org/u/raman_kumar)\
**Replies:** 16\
**Last updated:** [November 28, 2023, 2:50pm UTC](https://discourse.julialang.org/t/huion-inspiroy-2-tablet-driver-in-julia/106752 "2023-11-28T14:50:29Z")

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I have just bought HUION Inspiroy 2 tablet. I have used pamac build huiontablet command to install the driver. I am able to write but its driver is not allowing to customize tablet keys in Manjaro Linux . Can i write i…

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## [\[ANN\] New package: ObservableCortex.jl for surface-space fMRI data visualization](https://discourse.julialang.org/t/ann-new-package-observablecortex-jl-for-surface-space-fmri-data-visualization/106848)

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**Author:** [@myersm0](https://discourse.julialang.org/u/myersm0)\
**Replies:** 0\
**Last updated:** [November 28, 2023, 2:47pm UTC](https://discourse.julialang.org/t/ann-new-package-observablecortex-jl-for-surface-space-fmri-data-visualization/106848 "2023-11-28T14:47:01Z")

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When I switched from R to Julia about three years ago, one of the main things that made that an obvious choice for me, in my field (analysis of fMRI data), was the incredible Makie set of 3d plotting utilities. So first …

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## [How reliable is \`rank(A)\`?](https://discourse.julialang.org/t/how-reliable-is-rank-a/106834)

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**Author:** [@Mikulas\_Vanousek](https://discourse.julialang.org/u/Mikulas_Vanousek)\
**Replies:** 8\
**Last updated:** [November 28, 2023, 1:58pm UTC](https://discourse.julialang.org/t/how-reliable-is-rank-a/106834 "2023-11-28T13:58:44Z")

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The rank(A) function is not reliable. Here is an example, A has in fact rank 2. julia\> A = \[1 0; 10^8 1\] 2×2 Matrix{Int64}: 1 0 100000000 1 julia\> rank(A) 1 I understand this is inevitable for matricies wi…

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## [Extending Symbolics.jl, How to dispatch all functions to the underlying Num](https://discourse.julialang.org/t/extending-symbolics-jl-how-to-dispatch-all-functions-to-the-underlying-num/106845)

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**Author:** [@Qfl3x](https://discourse.julialang.org/u/Qfl3x)\
**Replies:** 2\
**Last updated:** [November 28, 2023, 1:34pm UTC](https://discourse.julialang.org/t/extending-symbolics-jl-how-to-dispatch-all-functions-to-the-underlying-num/106845 "2023-11-28T13:34:13Z")

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Hello, I want to extend Symbolics.jl Variables to encode bounds and default value of parameters in the “variable”; Currently something like this: using Symbolics: \_parse\_vars, Num, @variables import SciMLBase: issymbol…

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## [\[ANN\] ThreadPools.jl v1.0.0 - Improved thread management for background and nonuniform tasks](https://discourse.julialang.org/t/ann-threadpools-jl-v1-0-0-improved-thread-management-for-background-and-nonuniform-tasks/34138)

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**Author:** [@tro3](https://discourse.julialang.org/u/tro3)\
**Replies:** 9\
**Last updated:** [November 28, 2023, 12:51pm UTC](https://discourse.julialang.org/t/ann-threadpools-jl-v1-0-0-improved-thread-management-for-background-and-nonuniform-tasks/34138 "2023-11-28T12:51:39Z")

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All, I’m happy to announce a (breaking) API upgrade to ThreadPools.jl to better separate choices around handling background tasks and handling nonuniform tasks. Many thanks to @tkf and @ianshmean and many others who co…

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## [Calling .NET Framework from Julia](https://discourse.julialang.org/t/calling-net-framework-from-julia/106808)

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**Author:** [@Titas22](https://discourse.julialang.org/u/Titas22)\
**Replies:** 1\
**Last updated:** [November 28, 2023, 12:30pm UTC](https://discourse.julialang.org/t/calling-net-framework-from-julia/106808 "2023-11-28T12:30:46Z")

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Hi, I’m looking for a way to call and use .NET Framework (4.7) dlls from Julia, unfortunately the only options I’ve found for using .NET only cover the non-framework versions of .NET. Unfortunately the libraries I need…

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## [Yield in iterator](https://discourse.julialang.org/t/yield-in-iterator/106833)

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**Author:** [@cesarmarinhorj](https://discourse.julialang.org/u/cesarmarinhorj)\
**Replies:** 5\
**Last updated:** [November 28, 2023, 12:00pm UTC](https://discourse.julialang.org/t/yield-in-iterator/106833 "2023-11-28T12:00:07Z")

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How can I use a “yield” inside a function like a generator/iterator? function results() yield 1 yield 2 yield 3 }

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## [How to separate joint and disjoint intervals from an interval vector?](https://discourse.julialang.org/t/how-to-separate-joint-and-disjoint-intervals-from-an-interval-vector/106515)

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**Author:** [@Ashu](https://discourse.julialang.org/u/Ashu)\
**Replies:** 17\
**Last updated:** [November 28, 2023, 11:56am UTC](https://discourse.julialang.org/t/how-to-separate-joint-and-disjoint-intervals-from-an-interval-vector/106515 "2023-11-28T11:56:42Z")

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Hello, I have a vector. Each element of the vector is a tuple that contains two elements, an interval, and a set of three intervals. I want to separate and take unions of those elements of the vector that contain an emp…

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## [Unable to download locally Julia Package AerialVehicles.jl](https://discourse.julialang.org/t/unable-to-download-locally-julia-package-aerialvehicles-jl/106831)

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**Author:** [@alexander-leong](https://discourse.julialang.org/u/alexander-leong)\
**Replies:** 1\
**Last updated:** [November 28, 2023, 10:37am UTC](https://discourse.julialang.org/t/unable-to-download-locally-julia-package-aerialvehicles-jl/106831 "2023-11-28T10:37:31Z")

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Please help, I’m unable to download locally the AerialVehicles.jl package. I attempted to follow the instructions at Using JuliaSim Packages Locally via the JuliaHub Registry · JuliaSim which suggests connecting to Julia…

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## [Function definition with parametric types](https://discourse.julialang.org/t/function-definition-with-parametric-types/106830)

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**Author:** [@oliviermilla](https://discourse.julialang.org/u/oliviermilla)\
**Replies:** 3\
**Last updated:** [November 28, 2023, 10:11am UTC](https://discourse.julialang.org/t/function-definition-with-parametric-types/106830 "2023-11-28T10:11:28Z")

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Hello, It’s a basic question, but it’s still unclear to me. What are the functional differences between the function definitions below? struct A{T} end func(a::A) = #code func(a\<:A) = #code func(a::A{T}) where {T} =…

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## [\[ANN\] ODINN.jl: Universal Differential Equations for climate-glacier interactions](https://discourse.julialang.org/t/ann-odinn-jl-universal-differential-equations-for-climate-glacier-interactions/100396)

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**Author:** [@JordiBolibar](https://discourse.julialang.org/u/JordiBolibar)\
**Replies:** 1\
**Last updated:** [November 28, 2023, 9:03am UTC](https://discourse.julialang.org/t/ann-odinn-jl-universal-differential-equations-for-climate-glacier-interactions/100396 "2023-11-28T09:03:28Z")

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Announcing ODINN.jl, a global glacier model using Universal Differential Equations to learn empirical laws of glacier physics from large remote sensing datasets. This is my first Julia package, and the result of the last…

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## [Unexpected sensitivity to order of method definitions](https://discourse.julialang.org/t/unexpected-sensitivity-to-order-of-method-definitions/106510)

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**Author:** [@tverho](https://discourse.julialang.org/u/tverho)\
**Replies:** 11\
**Last updated:** [November 22, 2023, 8:03am UTC](https://discourse.julialang.org/t/unexpected-sensitivity-to-order-of-method-definitions/106510 "2023-11-22T08:03:03Z")

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The following works like a charm: function f(a; b) a + b end function f(a) a + a end julia\> f(2) 4 julia\> f(2,b=1) 3 But reversing the order results in an error: function f(a) a + a end function f(a; b)…

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## [Random variables with different time scales in SDDP.jl](https://discourse.julialang.org/t/random-variables-with-different-time-scales-in-sddp-jl/106823)

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**Author:** [@Sorooshsa](https://discourse.julialang.org/u/Sorooshsa)\
**Replies:** 3\
**Last updated:** [November 28, 2023, 3:46am UTC](https://discourse.julialang.org/t/random-variables-with-different-time-scales-in-sddp-jl/106823 "2023-11-28T03:46:25Z")

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Hi everyone, Assume that we have a wind power production problem with two random variables: Demand Wind speed We aim to solve the problem for a year. There is a daily time scale for the state variables and controls. …

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## [Problem in reading TIFF floats file](https://discourse.julialang.org/t/problem-in-reading-tiff-floats-file/106610)

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**Author:** [@RunguangLi](https://discourse.julialang.org/u/RunguangLi)\
**Replies:** 8\
**Last updated:** [November 28, 2023, 3:17am UTC](https://discourse.julialang.org/t/problem-in-reading-tiff-floats-file/106610 "2023-11-28T03:17:06Z")

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When I read a tiff floats image (001.tif) using FileIO by real(load("001.tif")), I get a matrix with only 1.0 and 0.0 elements. 360×2304 Array{N0f32,2} with eltype FixedPointNumbers.N0f32: 0.0 0.0 0.0 0.0 0.0 0.0 …

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