# Latest

**URL:** https://discourse.julialang.org/latest.md?page=188

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

**Page:** 189

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## [Estimate the relation of parameter to state variable with uncertainty quantification](https://discourse.julialang.org/t/estimate-the-relation-of-parameter-to-state-variable-with-uncertainty-quantification/127450)

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**Author:** [@Jack\_cooper](https://discourse.julialang.org/u/Jack_cooper)\
**Replies:** 3\
**Last updated:** [April 7, 2025, 8:48am UTC](https://discourse.julialang.org/t/estimate-the-relation-of-parameter-to-state-variable-with-uncertainty-quantification/127450 "2025-04-07T08:48:05Z")

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Hi, I am new to the SciML ecosystem, and I apologise if my question is too basic. I have a 1D differential equation system, dx/dt = f(x; p), where the parameter p is a function of the state variable. Given data for the s…

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## [Excessive memory consumption when optimising Gaussian process regression with automatic reverse differentiation](https://discourse.julialang.org/t/excessive-memory-consumption-when-optimising-gaussian-process-regression-with-automatic-reverse-differentiation/127772)

<div class="topic-metadata">

**Author:** [@Nikos\_Gianniotis](https://discourse.julialang.org/u/Nikos_Gianniotis)\
**Replies:** 2\
**Last updated:** [April 7, 2025, 6:27am UTC](https://discourse.julialang.org/t/excessive-memory-consumption-when-optimising-gaussian-process-regression-with-automatic-reverse-differentiation/127772 "2025-04-07T06:27:01Z")

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I am working on a model involving Gaussian processes and I am optimising it using Optim.jl while obtaining gradients via DifferentiationInterface.jl. Unfortunately, when I run the code, the top utility informs me that th…

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## [\[ANN\] GeoIDs.jl: a package to create a postgres/postgis database of TIGER county boundaries](https://discourse.julialang.org/t/ann-geoids-jl-a-package-to-create-a-postgres-postgis-database-of-tiger-county-boundaries/127778)

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**Author:** [@technocrat](https://discourse.julialang.org/u/technocrat)\
**Replies:** 3\
**Last updated:** [April 7, 2025, 10:40am UTC](https://discourse.julialang.org/t/ann-geoids-jl-a-package-to-create-a-postgres-postgis-database-of-tiger-county-boundaries/127778 "2025-04-07T10:40:40Z")

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GeoIDs.jl provides a comprehensive solution for working with Census GEOID identifiers, particularly at the county level. The package enables you to: Create and Manage Geographic Area Sets: Define sets of counties for …

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## [Morse code day - April 27th](https://discourse.julialang.org/t/morse-code-day-april-27th/80261)

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**Author:** [@scelles](https://discourse.julialang.org/u/scelles)\
**Replies:** 4\
**Last updated:** [April 7, 2025, 7:54am UTC](https://discourse.julialang.org/t/morse-code-day-april-27th/80261 "2025-04-07T07:54:23Z")

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Hello, Morse code day was April 27th https://www.daysoftheyear.com/days/morse-code-day/ I noticed no package for morse code seems to exist with Julia Here is my small (and late) contribution module MorseCode using …

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## [Is there a way to dynamically add/remove of reactions from ReactionSystem in catalyst](https://discourse.julialang.org/t/is-there-a-way-to-dynamically-add-remove-of-reactions-from-reactionsystem-in-catalyst/127411)

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**Author:** [@atiyabzafar](https://discourse.julialang.org/u/atiyabzafar)\
**Replies:** 3\
**Last updated:** [April 7, 2025, 7:22am UTC](https://discourse.julialang.org/t/is-there-a-way-to-dynamically-add-remove-of-reactions-from-reactionsystem-in-catalyst/127411 "2025-04-07T07:22:05Z")

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Hi I am trying to figure out a way to dynamically add/remove reactions once I have defined a ReactionSystem programmatically. Suppose I define the system using this function. function generate\_creation(n,MAT) # Cre…

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## [Extracting wave numbers using FFT and 2D data](https://discourse.julialang.org/t/extracting-wave-numbers-using-fft-and-2d-data/127758)

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**Author:** [@Gravlax](https://discourse.julialang.org/u/Gravlax)\
**Replies:** 3\
**Last updated:** [April 6, 2025, 7:13pm UTC](https://discourse.julialang.org/t/extracting-wave-numbers-using-fft-and-2d-data/127758 "2025-04-06T19:13:36Z")

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Dear all, I am trying to write a basic script that extract sthe wave numbers of a 2D signal (defined in ‘spatial coordinates’) using FFTW. To test the script, I want to define a signal where the wave numbers in x and y…

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## [How to interpret "Type{T} where T" in Julia's type system](https://discourse.julialang.org/t/how-to-interpret-type-t-where-t-in-julias-type-system/37402)

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**Author:** [@samuel](https://discourse.julialang.org/u/samuel)\
**Replies:** 22\
**Last updated:** [April 7, 2025, 6:45am UTC](https://discourse.julialang.org/t/how-to-interpret-type-t-where-t-in-julias-type-system/37402 "2025-04-07T06:45:02Z")

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I have some problems parsing the Julias type-system.. and I came up with a few questions. Docs - Types: “Type{T} is an abstract type whose only instance is the object T” How can an abstract type have instances?? As …

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## [Adding lazy cuts to an LP using JuMP.@build\_constraint](https://discourse.julialang.org/t/adding-lazy-cuts-to-an-lp-using-jump-build-constraint/127764)

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**Author:** [@WalterMadelim](https://discourse.julialang.org/u/WalterMadelim)\
**Replies:** 3\
**Last updated:** [April 7, 2025, 6:43am UTC](https://discourse.julialang.org/t/adding-lazy-cuts-to-an-lp-using-jump-build-constraint/127764 "2025-04-07T06:43:58Z")

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As the title suggests, I create a structure (the begin-end block) and wrote a procedure (while-end). import JuMP, Gurobi; GRB\_ENV = Gurobi.Env(); COT = 1e-7 # cut-off tolerance model = JuMP.direct\_model(Gurobi.Optimize…

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## [Anything like Distributions.jl but works on GPU in 2025?](https://discourse.julialang.org/t/anything-like-distributions-jl-but-works-on-gpu-in-2025/127783)

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**Author:** [@jling](https://discourse.julialang.org/u/jling)\
**Replies:** 0\
**Last updated:** [April 7, 2025, 4:46am UTC](https://discourse.julialang.org/t/anything-like-distributions-jl-but-works-on-gpu-in-2025/127783 "2025-04-07T04:46:24Z")

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Anything like Distributions.jl for GPU? was the previous discussion. I guess the answer is still no: CUDA support ? · Issue #1183 · JuliaStats/Distributions.jl · GitHub Calculating Distributions PDF in the GPU · Issue…

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## [Connecting points in VegaDatasets](https://discourse.julialang.org/t/connecting-points-in-vegadatasets/127773)

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**Author:** [@angeloaliano1](https://discourse.julialang.org/u/angeloaliano1)\
**Replies:** 1\
**Last updated:** [April 6, 2025, 11:20pm UTC](https://discourse.julialang.org/t/connecting-points-in-vegadatasets/127773 "2025-04-06T23:20:29Z")

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Hello users, I have the following code, works perfectly: \*\* world110m = dataset("world-110m") # canvas canvas = @vlplot( width = 640, height = 360, title = "Big cities in the world", projection = {typ…

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## [Change x axis so 0dg points north?](https://discourse.julialang.org/t/change-x-axis-so-0dg-points-north/127733)

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**Author:** [@abletec](https://discourse.julialang.org/u/abletec)\
**Replies:** 5\
**Last updated:** [April 6, 2025, 11:06pm UTC](https://discourse.julialang.org/t/change-x-axis-so-0dg-points-north/127733 "2025-04-06T23:06:05Z")

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I’m really new to Julia but like what I see so far. My goal is to write a program to help blind folks draw. For kids, it’ll help w/spatial orientation. For everyone, it’ll help them to communicate using graphics. Likely …

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## [Enzyme AD with matrix exponential](https://discourse.julialang.org/t/enzyme-ad-with-matrix-exponential/123094)

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**Author:** [@stone44](https://discourse.julialang.org/u/stone44)\
**Replies:** 22\
**Last updated:** [April 6, 2025, 10:43pm UTC](https://discourse.julialang.org/t/enzyme-ad-with-matrix-exponential/123094 "2025-04-06T22:43:00Z")

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Hey, I am currently trying to use Enzyme’s gradient function to get the gradient of a quantum mechanical expectation value in respect to some parameters which go into the Hamiltonian. What causes a problem? AD with Enz…

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## [How do I concatenate symbols containing curly brackets into a single symbol?](https://discourse.julialang.org/t/how-do-i-concatenate-symbols-containing-curly-brackets-into-a-single-symbol/127759)

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**Author:** [@Joris\_Pinkse](https://discourse.julialang.org/u/Joris_Pinkse)\
**Replies:** 4\
**Last updated:** [April 6, 2025, 9:18pm UTC](https://discourse.julialang.org/t/how-do-i-concatenate-symbols-containing-curly-brackets-into-a-single-symbol/127759 "2025-04-06T21:18:28Z")

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I’d like to obtain the code struct S{𝒯\<:Real} end programmatically. Method 1 below works, but I’d like to be able to feed in the variable name (here S) automatically (e.g. by passing a variable x containing :S) and he…

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## [Thread sanitizer troubles](https://discourse.julialang.org/t/thread-sanitizer-troubles/108507)

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**Author:** [@MilesCranmer](https://discourse.julialang.org/u/MilesCranmer)\
**Replies:** 9\
**Last updated:** [April 6, 2025, 8:06pm UTC](https://discourse.julialang.org/t/thread-sanitizer-troubles/108507 "2025-04-06T20:06:08Z")

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I’m wondering if anyone has experience with building Julia with thread sanitization (TSAN) before? I’ve tried maybe ~15 clean builds over the last year now, with different configurations after being recommended it (for t…

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## [Interactive Data Table in Pluto.jl (via a silly hack)](https://discourse.julialang.org/t/interactive-data-table-in-pluto-jl-via-a-silly-hack/44678)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 41\
**Last updated:** [April 6, 2025, 7:27pm UTC](https://discourse.julialang.org/t/interactive-data-table-in-pluto-jl-via-a-silly-hack/44678 "2025-04-06T19:27:24Z")

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@fonsp This is meant to be more fun than anything serious - I came up with a nice little hack for creating interactive data tables in my Pluto notebooks :slightly\_smiling\_face: After wrangling a .csv file into a Dict wi…

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## [Invoke previous method version with identical signature](https://discourse.julialang.org/t/invoke-previous-method-version-with-identical-signature/127757)

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**Author:** [@Ouroboros42](https://discourse.julialang.org/u/Ouroboros42)\
**Replies:** 2\
**Last updated:** [April 6, 2025, 7:01pm UTC](https://discourse.julialang.org/t/invoke-previous-method-version-with-identical-signature/127757 "2025-04-06T19:01:56Z")

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Very simple example: I have a function f with one method, I would like to redefine that method, but call the old implementation from inside the new one. invoke cannot do this for identical signatures. The following lead…

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## [When will the venue be announced for JuliaCon 2025 and when will tickets be for sale?](https://discourse.julialang.org/t/when-will-the-venue-be-announced-for-juliacon-2025-and-when-will-tickets-be-for-sale/127738)

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**Author:** [@AwesomeQuest](https://discourse.julialang.org/u/AwesomeQuest)\
**Replies:** 3\
**Last updated:** [April 6, 2025, 6:55pm UTC](https://discourse.julialang.org/t/when-will-the-venue-be-announced-for-juliacon-2025-and-when-will-tickets-be-for-sale/127738 "2025-04-06T18:55:17Z")

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Hi, just wondering if there is a timeline on when the venue will be announced for JuliaCon 2025 and when tickets will be for sale?

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## [Researcher in dispersion modeling, with option of doing a PhD](https://discourse.julialang.org/t/researcher-in-dispersion-modeling-with-option-of-doing-a-phd/127770)

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**Author:** [@barche](https://discourse.julialang.org/u/barche)\
**Replies:** 0\
**Last updated:** [April 6, 2025, 6:48pm UTC](https://discourse.julialang.org/t/researcher-in-dispersion-modeling-with-option-of-doing-a-phd/127770 "2025-04-06T18:48:57Z")

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Hi all, We are hiring a new researcher to continue our project on dispersion modeling, which involves development in Julia and Angular. The job starts in August and the location is Brussels. Details at: Royal Military …

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## [How are non programmers to use Julia Apps](https://discourse.julialang.org/t/how-are-non-programmers-to-use-julia-apps/127762)

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**Author:** [@TinWallop](https://discourse.julialang.org/u/TinWallop)\
**Replies:** 3\
**Last updated:** [April 6, 2025, 6:33pm UTC](https://discourse.julialang.org/t/how-are-non-programmers-to-use-julia-apps/127762 "2025-04-06T18:33:30Z")

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How are non programmers to use Apps written in Julia? I know this isn’t a new topic and I know about PackageManager etc. but I’m still confused about what Julia is for. Are you expecting people to install Julia? I migh…

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## [JuliaCon 2025: Travel Assistance](https://discourse.julialang.org/t/juliacon-2025-travel-assistance/127766)

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**Author:** [@ranjan](https://discourse.julialang.org/u/ranjan)\
**Replies:** 0\
**Last updated:** [April 6, 2025, 4:33pm UTC](https://discourse.julialang.org/t/juliacon-2025-travel-assistance/127766 "2025-04-06T16:33:40Z")

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Hello, If you are a speaker at JuliaCon 2025, you are welcome to apply for travel assistance. For more information, read and fill out the following form: Best, The JuliaCon 2025 Organizing Committee

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## [JuliaCon 2025: Tickets are now available](https://discourse.julialang.org/t/juliacon-2025-tickets-are-now-available/127765)

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**Author:** [@ranjan](https://discourse.julialang.org/u/ranjan)\
**Replies:** 0\
**Last updated:** [April 6, 2025, 4:31pm UTC](https://discourse.julialang.org/t/juliacon-2025-tickets-are-now-available/127765 "2025-04-06T16:31:07Z")

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Hi everyone, Tickets are now available for JuliaCon 2025, with the early bird rates now in effect. For more info, check: Act fast, because early bird rates close out on May 15, 2025. We look forward to seeing you th…

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## [Best library for calculating slope in an elevation raster?](https://discourse.julialang.org/t/best-library-for-calculating-slope-in-an-elevation-raster/114154)

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**Author:** [@rholland4julia](https://discourse.julialang.org/u/rholland4julia)\
**Replies:** 13\
**Last updated:** [April 6, 2025, 4:14pm UTC](https://discourse.julialang.org/t/best-library-for-calculating-slope-in-an-elevation-raster/114154 "2025-04-06T16:14:46Z")

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I am trying to calculate the slope from a large number of DEM rasters. It seems like Geomorphometry.jl has an implementation of the Horn (1981) method, but are there other library options?

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## [Brainstorming about a game engine's architecture](https://discourse.julialang.org/t/brainstorming-about-a-game-engines-architecture/127760)

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**Author:** [@Gesee](https://discourse.julialang.org/u/Gesee)\
**Replies:** 1\
**Last updated:** [April 6, 2025, 4:09pm UTC](https://discourse.julialang.org/t/brainstorming-about-a-game-engines-architecture/127760 "2025-04-06T16:09:57Z")

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Hello everyone, I have been thinking about making a game engine, so I did a little brainstorming about his architecture but since I new to Julia and programming in general (I started just 1.5 years ago as a self taught),…

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## [Data from Brazil states (and generic region) using VegaDatasets](https://discourse.julialang.org/t/data-from-brazil-states-and-generic-region-using-vegadatasets/127761)

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**Author:** [@angeloaliano1](https://discourse.julialang.org/u/angeloaliano1)\
**Replies:** 3\
**Last updated:** [April 6, 2025, 3:19pm UTC](https://discourse.julialang.org/t/data-from-brazil-states-and-generic-region-using-vegadatasets/127761 "2025-04-06T15:19:13Z")

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Dear all, I have the following code that draws the US map with its states: using VegaLite, VegaDatasets # load JSON file containing map of US us10m = dataset("us-10m") # 1. US Map by State # how to generate plot p …

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## [What is the best way to implement PINN in Julia](https://discourse.julialang.org/t/what-is-the-best-way-to-implement-pinn-in-julia/127713)

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**Author:** [@Yang-yang](https://discourse.julialang.org/u/Yang-yang)\
**Replies:** 18\
**Last updated:** [April 6, 2025, 2:37pm UTC](https://discourse.julialang.org/t/what-is-the-best-way-to-implement-pinn-in-julia/127713 "2025-04-06T14:37:28Z")

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Dear all, I want to use PINNs to solve a PDE. There are two packages in Julia that can do this NeuralPDE.jl and Sophon.jl Both of these packages use the finite difference method to realize derivatives. I want to know i…

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## [How to use Downloads.download() with SFTP?](https://discourse.julialang.org/t/how-to-use-downloads-download-with-sftp/76480)

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**Author:** [@Fred](https://discourse.julialang.org/u/Fred)\
**Replies:** 17\
**Last updated:** [April 6, 2025, 1:47pm UTC](https://discourse.julialang.org/t/how-to-use-downloads-download-with-sftp/76480 "2025-04-06T13:47:31Z")

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Hi, Is it possible to do SFTP with Julia ? I use filezilla to download files on a remote computer but I do not manage to access it with Julia. Is there something wrong in the URL format ? Thanks for your reply ! using…

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## [Static Compilation using StaticCompiler on Windows](https://discourse.julialang.org/t/static-compilation-using-staticcompiler-on-windows/109414)

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**Author:** [@Thomas008](https://discourse.julialang.org/u/Thomas008)\
**Replies:** 6\
**Last updated:** [April 6, 2025, 12:12pm UTC](https://discourse.julialang.org/t/static-compilation-using-staticcompiler-on-windows/109414 "2025-04-06T12:12:17Z")

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PackageCompiler builds the entire sysimage which is very large. StaticCompiler allows static compilation of Julia into small native biniaries. It uses StaticTools which helps avoiding GC allocations. Now it seems possib…

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## [Plotly in Julia - Questions](https://discourse.julialang.org/t/plotly-in-julia-questions/127727)

<div class="topic-metadata">

**Author:** [@Episki](https://discourse.julialang.org/u/Episki)\
**Replies:** 11\
**Last updated:** [April 6, 2025, 9:50am UTC](https://discourse.julialang.org/t/plotly-in-julia-questions/127727 "2025-04-06T09:50:34Z")

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Hi community, I’m re-starting my Julia journey since at work we have a toy project with it. I have a question regarding the use of Plotly in Julia, since it is the graphing library I mostly use in Python: What is the…

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## [JuMP: print constraint evaluated with start\_values of variables](https://discourse.julialang.org/t/jump-print-constraint-evaluated-with-start-values-of-variables/127752)

<div class="topic-metadata">

**Author:** [@lamont](https://discourse.julialang.org/u/lamont)\
**Replies:** 3\
**Last updated:** [April 6, 2025, 7:55am UTC](https://discourse.julialang.org/t/jump-print-constraint-evaluated-with-start-values-of-variables/127752 "2025-04-06T07:55:18Z")

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I’ve got a moderately complicated model that I’m trying to display the infeasibility of the start point via code that looks like: @constraint(model, dyn1, 0 == X1 - Ba \* V1 - Xa1 .\* ones(N)) @constraint(model, d…

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## [Call original method when redefining a method. (Compact float printing in IJulia)](https://discourse.julialang.org/t/call-original-method-when-redefining-a-method-compact-float-printing-in-ijulia/74111)

<div class="topic-metadata">

**Author:** [@tfiers](https://discourse.julialang.org/u/tfiers)\
**Replies:** 6\
**Last updated:** [April 6, 2025, 5:24am UTC](https://discourse.julialang.org/t/call-original-method-when-redefining-a-method-compact-float-printing-in-ijulia/74111 "2025-04-06T05:24:25Z")

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I want to print floats (and derived types such as Unitful.Quantity{Float64, …}) compactly in IJulia / the REPL. E.g. 0.1\*3 should be echoed as 0.3 and not 0.30000000000000004. Likewise, 0.1\*3mV should be 0.3 mV and not…

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