# Latest

**URL:** https://discourse.julialang.org/latest.md?page=216

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

**Page:** 217

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## [Labeling plots](https://discourse.julialang.org/t/labeling-plots/126074)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 6\
**Last updated:** [February 20, 2025, 10:02am UTC](https://discourse.julialang.org/t/labeling-plots/126074 "2025-02-20T10:02:03Z")

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This is strictly speaking not a Julia question, even though I am using Julia for plotting, but I guess that a lot of people here care about scientific visualization here so it is OK. The question is: if you are plotting…

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## [How to perform a sparse matrix dense matrix product with addition (cuda library style)](https://discourse.julialang.org/t/how-to-perform-a-sparse-matrix-dense-matrix-product-with-addition-cuda-library-style/126093)

<div class="topic-metadata">

**Author:** [@victor\_vhrn](https://discourse.julialang.org/u/victor_vhrn)\
**Replies:** 1\
**Last updated:** [February 20, 2025, 7:33am UTC](https://discourse.julialang.org/t/how-to-perform-a-sparse-matrix-dense-matrix-product-with-addition-cuda-library-style/126093 "2025-02-20T07:33:09Z")

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I want to compute the following result = -1 \* (e \* (e' \* U)) + M \* U Where e = ones(n,1), M is a n x n CuSparseMatrixCSR and U is a n x r dense CuMatrix. Since it is my understanding that the above operation invokes 4…

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## [Use of anonymous functions has high compilation time](https://discourse.julialang.org/t/use-of-anonymous-functions-has-high-compilation-time/125923)

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**Author:** [@thomasc791](https://discourse.julialang.org/u/thomasc791)\
**Replies:** 3\
**Last updated:** [February 14, 2025, 10:17pm UTC](https://discourse.julialang.org/t/use-of-anonymous-functions-has-high-compilation-time/125923 "2025-02-14T22:17:58Z")

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Hi everyone, I am currently struggling with the usage of anonymous functions. I have a function dirichlet! that takes a function as one of its inputs. The function returns a value based on the position x. function diri…

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## [Filter dataframe with regular expression](https://discourse.julialang.org/t/filter-dataframe-with-regular-expression/76888)

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**Author:** [@Mastomaki](https://discourse.julialang.org/u/Mastomaki)\
**Replies:** 8\
**Last updated:** [February 20, 2025, 2:44am UTC](https://discourse.julialang.org/t/filter-dataframe-with-regular-expression/76888 "2025-02-20T02:44:05Z")

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Hello, I am trying to filter a dataframe based on values in certain column. This works fine when I use subset() with ByRow(in(\[“mytext”\])). But I get problems with regular expressions: df = subset(df, :mycol =\> x -\> By…

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## [Announcing PortfolioAnalytics.jl: Tool for Quantitative Portfolio Analytics](https://discourse.julialang.org/t/announcing-portfolioanalytics-jl-tool-for-quantitative-portfolio-analytics/95236)

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**Author:** [@mdogan](https://discourse.julialang.org/u/mdogan)\
**Replies:** 16\
**Last updated:** [February 20, 2025, 2:36am UTC](https://discourse.julialang.org/t/announcing-portfolioanalytics-jl-tool-for-quantitative-portfolio-analytics/95236 "2025-02-20T02:36:04Z")

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Tool for Quantitative Portfolio Analytics I’m happy to announce PortfolioAnalytics.jl, which aims to provide users with functionality for performing quantitative portfolio analytics. Introduction · PortfolioAnalytics.jl…

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## [Newbie plotting frustration](https://discourse.julialang.org/t/newbie-plotting-frustration/126049)

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**Author:** [@dwannetts](https://discourse.julialang.org/u/dwannetts)\
**Replies:** 10\
**Last updated:** [February 19, 2025, 11:50pm UTC](https://discourse.julialang.org/t/newbie-plotting-frustration/126049 "2025-02-19T23:50:34Z")

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Hi All, I have been developing a significant level of frustration over the past few weeks. On one hand, Julia appears fast and able to deal with the data that I need to deal with, at least up to a point. Documentation…

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## [Introducing SymJul: Symbolic Analysis for Differential Equations](https://discourse.julialang.org/t/introducing-symjul-symbolic-analysis-for-differential-equations/126035)

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**Author:** [@erny123](https://discourse.julialang.org/u/erny123)\
**Replies:** 14\
**Last updated:** [February 20, 2025, 1:26am UTC](https://discourse.julialang.org/t/introducing-symjul-symbolic-analysis-for-differential-equations/126035 "2025-02-20T01:26:00Z")

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Dear all, I’d like to introduce: SymJul (not married to the name) I’m working on a lot of theory for new nonlinear systems. Sometimes, discretization of the full ODE or PDE works but takes too many computational reso…

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## [\[ANN\] LearnAPI.jl 1.0: General API for ML/statistics](https://discourse.julialang.org/t/ann-learnapi-jl-1-0-general-api-for-ml-statistics/126089)

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**Author:** [@ablaom](https://discourse.julialang.org/u/ablaom)\
**Replies:** 1\
**Last updated:** [February 19, 2025, 9:30pm UTC](https://discourse.julialang.org/t/ann-learnapi-jl-1-0-general-api-for-ml-statistics/126089 "2025-02-19T21:30:01Z")

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This is the first official and stable release of LearnAPI.jl, a new general API for machine learning and statistics. This is not a general ML toolbox but aims to support toolbox meta-algorithms, such as cross-validation,…

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## [\[ANN\] LearnAPI.jl - Proposal for a basement-level machine learning API](https://discourse.julialang.org/t/ann-learnapi-jl-proposal-for-a-basement-level-machine-learning-api/93048)

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**Author:** [@ablaom](https://discourse.julialang.org/u/ablaom)\
**Replies:** 112\
**Last updated:** [February 19, 2025, 9:08pm UTC](https://discourse.julialang.org/t/ann-learnapi-jl-proposal-for-a-basement-level-machine-learning-api/93048 "2025-02-19T21:08:19Z")

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Feedback is being sought on a new, detailed proposal, called LearnAPI.jl, for a general purpose low-level machine learning interface. The proposal is based on our three years’ experience developing and maintaining the ma…

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## [ModelingToolkit -- changes with \`remake\`?](https://discourse.julialang.org/t/modelingtoolkit-changes-with-remake/126004)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 2\
**Last updated:** [February 19, 2025, 7:07pm UTC](https://discourse.julialang.org/t/modelingtoolkit-changes-with-remake/126004 "2025-02-19T19:07:19Z")

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I have a @mtkbuild model named hp\_na\_ns\_oL which uses some register\_symbolic function u\_u\_v(t) that I specify via a constant value function u\_v\_const(). I want to simulate the system to steady state, and use the steady s…

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## [Mul! allocates for custom struct which is a subtype of AbstractMatrix](https://discourse.julialang.org/t/mul-allocates-for-custom-struct-which-is-a-subtype-of-abstractmatrix/126078)

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**Author:** [@Giorgos\_Vretinaris](https://discourse.julialang.org/u/Giorgos_Vretinaris)\
**Replies:** 2\
**Last updated:** [February 19, 2025, 6:35pm UTC](https://discourse.julialang.org/t/mul-allocates-for-custom-struct-which-is-a-subtype-of-abstractmatrix/126078 "2025-02-19T18:35:08Z")

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I am trying to write an efficient matricization function following Kolda’s and Bader’s work on “Tensor Decompositions and Applications”. The struct I have is non-allocating when initialized as it is basically a lazy view…

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## [Can Turing differentiate a truncated Poisson](https://discourse.julialang.org/t/can-turing-differentiate-a-truncated-poisson/126082)

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**Author:** [@Domenic\_Di\_Francesco](https://discourse.julialang.org/u/Domenic_Di_Francesco)\
**Replies:** 1\
**Last updated:** [February 19, 2025, 5:49pm UTC](https://discourse.julialang.org/t/can-turing-differentiate-a-truncated-poisson/126082 "2025-02-19T17:49:55Z")

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does Turing’s AD backend struggle with truncated Poisson distributions? Turing.@model function bps\_hurdle\_model(bonus::Vector{Int}, bps::Vector{Int}, μ\_αbps = 0, σ\_αbps = 1, μ\_βbps = 0, σ\_βbps = 1) α\_pzero ~ N…

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## [Julia VSC extension not loading](https://discourse.julialang.org/t/julia-vsc-extension-not-loading/126084)

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**Author:** [@martin\_sanchez](https://discourse.julialang.org/u/martin_sanchez)\
**Replies:** 1\
**Last updated:** [February 19, 2025, 5:21pm UTC](https://discourse.julialang.org/t/julia-vsc-extension-not-loading/126084 "2025-02-19T17:21:46Z")

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Hi, I had used before VSC for Julia and the notebooks aswell. I was wondering if its this is just happening to me or a general thing, but very often for very vey simple tasks the notebook gets stuck, as in the following …

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## [Concatenated ranges](https://discourse.julialang.org/t/concatenated-ranges/126042)

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**Author:** [@RainerHeintzmann](https://discourse.julialang.org/u/RainerHeintzmann)\
**Replies:** 7\
**Last updated:** [February 19, 2025, 4:51pm UTC](https://discourse.julialang.org/t/concatenated-ranges/126042 "2025-02-19T16:51:44Z")

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For some applications concatenated ranges would be nice. E.g. it would simplify working with rotated indices, obviating the need for fftshift for some calculations. E.g. if I want to construct a suitable Gaussian in Four…

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## [MultiObjectiveAlgorithms.jl (skipping infeasible solutions)](https://discourse.julialang.org/t/multiobjectivealgorithms-jl-skipping-infeasible-solutions/126003)

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**Author:** [@saikrishna-nadella](https://discourse.julialang.org/u/saikrishna-nadella)\
**Replies:** 9\
**Last updated:** [February 19, 2025, 4:32pm UTC](https://discourse.julialang.org/t/multiobjectivealgorithms-jl-skipping-infeasible-solutions/126003 "2025-02-19T16:32:16Z")

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Hi, I am using MultiObjectiveAlgorithms.jl with EpsilonConstraint method. When a small number of SolutionLimit is used, it went well and pareto front could be obtained. But, when I increase SolutionLimit to higher value…

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## [Help debugging failing precompilation of DuckDB.jl \[Windows\]](https://discourse.julialang.org/t/help-debugging-failing-precompilation-of-duckdb-jl-windows/122226)

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**Author:** [@TheLateKronos](https://discourse.julialang.org/u/TheLateKronos)\
**Replies:** 3\
**Last updated:** [February 19, 2025, 4:30pm UTC](https://discourse.julialang.org/t/help-debugging-failing-precompilation-of-duckdb-jl-windows/122226 "2025-02-19T16:30:19Z")

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When installing DuckDB.jl on windows, precompilation fails: The issue is caused by failing precompilation of the DuckDB\_jll binary. Stacktrace(@v1.11) pkg\> add DuckDB Updating registry at \`C:\\Users\\dennis.bal\\.j…

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## [ERROR: KeyError: key "SparseArrays" not found](https://discourse.julialang.org/t/error-keyerror-key-sparsearrays-not-found/125980)

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**Author:** [@Eventine](https://discourse.julialang.org/u/Eventine)\
**Replies:** 11\
**Last updated:** [February 19, 2025, 3:01pm UTC](https://discourse.julialang.org/t/error-keyerror-key-sparsearrays-not-found/125980 "2025-02-19T15:01:20Z")

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I’m new to Julia, I had a project that was using ControlSystems and SparseArrays packages. After the weekend I came back to the office, lauched a test, and nothing was working. Basically it says that I cannot compile Con…

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## [Hydrograd.jl: A framework for differentiable hydrodynamics modeling and scientifc machine learning](https://discourse.julialang.org/t/hydrograd-jl-a-framework-for-differentiable-hydrodynamics-modeling-and-scientifc-machine-learning/126076)

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**Author:** [@foolcat](https://discourse.julialang.org/u/foolcat)\
**Replies:** 0\
**Last updated:** [February 19, 2025, 2:49pm UTC](https://discourse.julialang.org/t/hydrograd-jl-a-framework-for-differentiable-hydrodynamics-modeling-and-scientifc-machine-learning/126076 "2025-02-19T14:49:52Z")

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Package repository: https://github.com/psu-efd/Hydrograd.jl Manuscript under review: \[2502.12396\] Scientific Machine Learning of Flow Resistance Using Universal Shallow Water Equations with Differentiable Programming H…

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## [Remote Sensing & Forestry in Göttingen, Germany](https://discourse.julialang.org/t/remote-sensing-forestry-in-gottingen-germany/125365)

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**Author:** [@maxfreu](https://discourse.julialang.org/u/maxfreu)\
**Replies:** 5\
**Last updated:** [February 19, 2025, 2:37pm UTC](https://discourse.julialang.org/t/remote-sensing-forestry-in-gottingen-germany/125365 "2025-02-19T14:37:57Z")

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Hi! My professor is looking for someone who can help building a national geodata information system focused on forests. The position is fixed term until end of 2027. The salary should be around 3500€ per month upwards, …

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## [Comment request on code structure on a multi-components multi-regional model](https://discourse.julialang.org/t/comment-request-on-code-structure-on-a-multi-components-multi-regional-model/126073)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 0\
**Last updated:** [February 19, 2025, 1:51pm UTC](https://discourse.julialang.org/t/comment-request-on-code-structure-on-a-multi-components-multi-regional-model/126073 "2025-02-19T13:51:10Z")

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I am developing a model that has several components and at the same time several “regions” that specialize the various components. I am keeping all in a single package for easy of development in the early stages, but I …

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## [Isn't the official style guide a bit a messed up of different things?](https://discourse.julialang.org/t/isnt-the-official-style-guide-a-bit-a-messed-up-of-different-things/126058)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 1\
**Last updated:** [February 19, 2025, 12:57pm UTC](https://discourse.julialang.org/t/isnt-the-official-style-guide-a-bit-a-messed-up-of-different-things/126058 "2025-02-19T12:57:52Z")

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Am I the only one to think that the Style Guide in the official doc is a bit a mix of two separate things? While similar at the higher level, for “style guide” you may meaning two things that remain separate: First, st…

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## [Filtering doctests issue](https://discourse.julialang.org/t/filtering-doctests-issue/126070)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 0\
**Last updated:** [February 19, 2025, 12:32pm UTC](https://discourse.julialang.org/t/filtering-doctests-issue/126070 "2025-02-19T12:32:32Z")

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I’m trying to filter in a jldoctest the lines of \[ Info: blocks. I’m trying this, within a docstring of a function: \`\`\`jldoctest ;filter = r"^\\\\s\*\\\\\[ Info:.\*"m =\> "" but that is not filtering. The corresponding regexp…

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## [Recent issues downloading files (Downloads.download())](https://discourse.julialang.org/t/recent-issues-downloading-files-downloads-download/126040)

<div class="topic-metadata">

**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 5\
**Last updated:** [February 19, 2025, 12:23pm UTC](https://discourse.julialang.org/t/recent-issues-downloading-files-downloads-download/126040 "2025-02-19T12:23:21Z")

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I started to have issues recently downloading some files with Downloads.download(). The issues are not quite deterministic, but they seem to persist for a while. For example, now, this file: https://files.rcsb.org/view/…

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## [Abnormal behaviour when using callback two times in the same script](https://discourse.julialang.org/t/abnormal-behaviour-when-using-callback-two-times-in-the-same-script/126062)

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**Author:** [@Sushrut\_Deshpande](https://discourse.julialang.org/u/Sushrut_Deshpande)\
**Replies:** 1\
**Last updated:** [February 19, 2025, 12:05pm UTC](https://discourse.julialang.org/t/abnormal-behaviour-when-using-callback-two-times-in-the-same-script/126062 "2025-02-19T12:05:02Z")

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Hello, I have a MWE here for when I solve a ODE with callback two times in the same script , it solves the first one case expected and does not for the second one. using DifferentialEquations, Plots, OrdinaryDiffEq f…

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## [Flatten dicts of dicts in DataFrame](https://discourse.julialang.org/t/flatten-dicts-of-dicts-in-dataframe/125995)

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**Author:** [@stene](https://discourse.julialang.org/u/stene)\
**Replies:** 16\
**Last updated:** [February 19, 2025, 11:15am UTC](https://discourse.julialang.org/t/flatten-dicts-of-dicts-in-dataframe/125995 "2025-02-19T11:15:06Z")

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I have a vector of dicts where some entries contains dicts which I want to process in a DafaFrame. I want to flatten the dicts inside the dicts to make it easier to work with the data. I cannot find the correct command. …

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## [Differentiating through non-negative least squares solver?](https://discourse.julialang.org/t/differentiating-through-non-negative-least-squares-solver/125641)

<div class="topic-metadata">

**Author:** [@ElOceanografo](https://discourse.julialang.org/u/ElOceanografo)\
**Replies:** 9\
**Last updated:** [February 19, 2025, 10:55am UTC](https://discourse.julialang.org/t/differentiating-through-non-negative-least-squares-solver/125641 "2025-02-19T10:55:18Z")

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Hi, I’m wondering if there’s a better way to get the gradient of a function like this one: using NonNegLeastSquares, DifferentiationInterface import FiniteDiff function f(aa, b) A = reshape(aa, size(b, 1), :) x…

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## [An error occurred while building the environment](https://discourse.julialang.org/t/an-error-occurred-while-building-the-environment/126053)

<div class="topic-metadata">

**Author:** [@Spurs15437](https://discourse.julialang.org/u/Spurs15437)\
**Replies:** 1\
**Last updated:** [February 19, 2025, 9:08am UTC](https://discourse.julialang.org/t/an-error-occurred-while-building-the-environment/126053 "2025-02-19T09:08:19Z")

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(jl\_79BdVv) pkg\> precompile Precompiling project... ✗ NCDatasets ✗ DIVAnd 0 dependencies successfully precompiled in 5 seconds. 199 already precompiled. ERROR: The following 1 direct dependency failed to precompil…

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## [Heatmap of data not on a grid](https://discourse.julialang.org/t/heatmap-of-data-not-on-a-grid/126022)

<div class="topic-metadata">

**Author:** [@evanderveer](https://discourse.julialang.org/u/evanderveer)\
**Replies:** 6\
**Last updated:** [February 19, 2025, 9:04am UTC](https://discourse.julialang.org/t/heatmap-of-data-not-on-a-grid/126022 "2025-02-19T09:04:38Z")

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I have been trying to make a heatmap of some experimental data using Makie. When the x,y positions of the datapoints are on a grid, this works just fine: using CairoMakie i = 1 for x in 1:5 for y in 1:5 xys…

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## [Unable to fetch GH Release tarballs for JLL package on company internal GitHub server](https://discourse.julialang.org/t/unable-to-fetch-gh-release-tarballs-for-jll-package-on-company-internal-github-server/126056)

<div class="topic-metadata">

**Author:** [@briyoman](https://discourse.julialang.org/u/briyoman)\
**Replies:** 0\
**Last updated:** [February 19, 2025, 4:01am UTC](https://discourse.julialang.org/t/unable-to-fetch-gh-release-tarballs-for-jll-package-on-company-internal-github-server/126056 "2025-02-19T04:01:09Z")

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I’m working on a package that is generated using BinaryBuilder. The generated package is hosted on a company internal GitHub server. Due to access permissions/restrictions, Julia is unable to download the “Release tarba…

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## [ExaModels optimizer API for JuMP has convergence issue](https://discourse.julialang.org/t/examodels-optimizer-api-for-jump-has-convergence-issue/126032)

<div class="topic-metadata">

**Author:** [@KSepetanc](https://discourse.julialang.org/u/KSepetanc)\
**Replies:** 5\
**Last updated:** [February 19, 2025, 12:30am UTC](https://discourse.julialang.org/t/examodels-optimizer-api-for-jump-has-convergence-issue/126032 "2025-02-19T00:30:18Z")

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It is my understanding that convergence should not depend on selection of AD package. I have tested many AD options on the same model and only one option has different convergence (number of iterations and reported value…

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