# Latest

**URL:** https://discourse.julialang.org/latest.md?page=712

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

**Page:** 713

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## [Repo for Scientific Machine Learning - UDE paper does not seem to give consistent results on rerunning](https://discourse.julialang.org/t/repo-for-scientific-machine-learning-ude-paper-does-not-seem-to-give-consistent-results-on-rerunning/98157)

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**Author:** [@Daniel\_Doyle](https://discourse.julialang.org/u/Daniel_Doyle)\
**Replies:** 3\
**Last updated:** [May 2, 2023, 7:24pm UTC](https://discourse.julialang.org/t/repo-for-scientific-machine-learning-ude-paper-does-not-seem-to-give-consistent-results-on-rerunning/98157 "2023-05-02T19:24:22Z")

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Hello, I was going through the code behind the paper for Scientific machine learning here: universal\_differential\_equations/scenario\_1.jl at master · ChrisRackauckas/universal\_differential\_equations · GitHub and I am n…

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## [How do I call a function in a lookup table while ensure type stability?](https://discourse.julialang.org/t/how-do-i-call-a-function-in-a-lookup-table-while-ensure-type-stability/98212)

<div class="topic-metadata">

**Author:** [@Kino](https://discourse.julialang.org/u/Kino)\
**Replies:** 4\
**Last updated:** [May 2, 2023, 7:08pm UTC](https://discourse.julialang.org/t/how-do-i-call-a-function-in-a-lookup-table-while-ensure-type-stability/98212 "2023-05-02T19:08:43Z")

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A simple example is: julia\> f() = 1 f (generic function with 1 method) julia\> g() = 2 g (generic function with 1 method) julia\> table = (f=f, g=g) (f = f, g = g) julia\> get\_val(x::Symbol) = table\[x\]()::Int get\_val (g…

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## [FastDense, FastChain](https://discourse.julialang.org/t/fastdense-fastchain/98210)

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**Author:** [@erlebach](https://discourse.julialang.org/u/erlebach)\
**Replies:** 4\
**Last updated:** [May 2, 2023, 5:29pm UTC](https://discourse.julialang.org/t/fastdense-fastchain/98210 "2023-05-02T17:29:13Z")

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Which package contains FastChain and FastDense? I am using Julia 1.9.rc1. Even though I loaded DiffEqFluxn and Flux, FastChain and FastDense are not found. Any insight is appreciated. Thanks.

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## [Mixing set of continuous ODEs with probabilistic binary states](https://discourse.julialang.org/t/mixing-set-of-continuous-odes-with-probabilistic-binary-states/98209)

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**Author:** [@p\_f](https://discourse.julialang.org/u/p_f)\
**Replies:** 2\
**Last updated:** [May 2, 2023, 4:12pm UTC](https://discourse.julialang.org/t/mixing-set-of-continuous-odes-with-probabilistic-binary-states/98209 "2023-05-02T16:12:31Z")

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Say I have state vectors X1 and X2. X1 contains N1 continuous variables and X2 contains N2 binary (0 or 1) variables. X1 evolves in time according to function f1(X1,X2) and the binary variables in X2 have a probablity pe…

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## ['Optim' fails when supplying gradient and Hessian](https://discourse.julialang.org/t/optim-fails-when-supplying-gradient-and-hessian/98172)

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**Author:** [@PZacchia](https://discourse.julialang.org/u/PZacchia)\
**Replies:** 5\
**Last updated:** [May 2, 2023, 3:34pm UTC](https://discourse.julialang.org/t/optim-fails-when-supplying-gradient-and-hessian/98172 "2023-05-02T15:34:27Z")

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Fairly new to Julia, but I am loving it. This forum is a GREAT support but I can’t get my head around a problem I am experiencing right now. I am trying to perform a Monte Carlo for a variation of the standard multinomia…

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## [How to include a column with a constant value in a DataFrames select](https://discourse.julialang.org/t/how-to-include-a-column-with-a-constant-value-in-a-dataframes-select/98203)

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**Author:** [@kobusherbst](https://discourse.julialang.org/u/kobusherbst)\
**Replies:** 3\
**Last updated:** [May 2, 2023, 2:58pm UTC](https://discourse.julialang.org/t/how-to-include-a-column-with-a-constant-value-in-a-dataframes-select/98203 "2023-05-02T14:58:13Z")

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I have the following working example: using DataFrames # Create a DataFrame data = DataFrame(Name=\["Alice", "Bob", "Cathy", "David"\], Age=\[30, 25, 27, 28\], City=\["New York", "San Franc…

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## [Is Cthulhu wrong? Or is it the compiler?](https://discourse.julialang.org/t/is-cthulhu-wrong-or-is-it-the-compiler/98071)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 17\
**Last updated:** [May 2, 2023, 2:42pm UTC](https://discourse.julialang.org/t/is-cthulhu-wrong-or-is-it-the-compiler/98071 "2023-05-02T14:42:21Z")

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In this fragment, Cthulhu concludes that all types are concrete, known. Yet, at the bottom it suddenly springs on me csuml is Any. I considered log, and used abs for its argument. To no avail. Any idea how to fix it, a…

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## [Building Julia documentation using Typst](https://discourse.julialang.org/t/building-julia-documentation-using-typst/97498)

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**Author:** [@lucifer1004](https://discourse.julialang.org/u/lucifer1004)\
**Replies:** 22\
**Last updated:** [April 20, 2023, 12:50pm UTC](https://discourse.julialang.org/t/building-julia-documentation-using-typst/97498 "2023-04-20T12:50:23Z")

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I just wrote a Typst backend for Documenter.jl and managed to build the latest Julia documentation. Footnotes are not supported yet, while math equations are kept as is since Typst uses a different grammar and there i…

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## [Correct way to ccall a Fortran subroutine requiring pointers](https://discourse.julialang.org/t/correct-way-to-ccall-a-fortran-subroutine-requiring-pointers/98191)

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**Author:** [@lucifer1004](https://discourse.julialang.org/u/lucifer1004)\
**Replies:** 3\
**Last updated:** [May 2, 2023, 11:27am UTC](https://discourse.julialang.org/t/correct-way-to-ccall-a-fortran-subroutine-requiring-pointers/98191 "2023-05-02T11:27:01Z")

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Given the following Fortran code: MODULE PTR IMPLICIT NONE REAL, SAVE, TARGET, ALLOCATABLE :: A(:, :), B(:, :) CONTAINS SUBROUTINE INIT(AP, BP) REAL, POINTER :: AP(:, :), BP(:, :) ALLOCATE(A(6, 6…

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## [MakieCon 23 - recordings available :)](https://discourse.julialang.org/t/makiecon-23-recordings-available/98192)

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**Author:** [@sdanisch](https://discourse.julialang.org/u/sdanisch)\
**Replies:** 0\
**Last updated:** [May 2, 2023, 11:12am UTC](https://discourse.julialang.org/t/makiecon-23-recordings-available/98192 "2023-05-02T11:12:53Z")

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We finally got all the talks published for MakieCon 23! You’ll find them at the JuliaLang youtube channel under the MakieCon 23 playlist. Thanks to everyone who made this such a fantastic event!

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## [Coalescing DataFrame columns and record source](https://discourse.julialang.org/t/coalescing-dataframe-columns-and-record-source/97988)

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**Author:** [@mreichMPI-BGC](https://discourse.julialang.org/u/mreichMPI-BGC)\
**Replies:** 3\
**Last updated:** [May 2, 2023, 7:14am UTC](https://discourse.julialang.org/t/coalescing-dataframe-columns-and-record-source/97988 "2023-05-02T07:14:55Z")

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Dear Julia Data community, I would like to coalesce entries across columns of a DataFrame and record where the value is coming from. I came up with the following function, which seems to work but feels a bit cumbersome…

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## [PlutoNoteBook realtime data, web page is it possible or do we head for python?](https://discourse.julialang.org/t/plutonotebook-realtime-data-web-page-is-it-possible-or-do-we-head-for-python/98126)

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**Author:** [@1153dent](https://discourse.julialang.org/u/1153dent)\
**Replies:** 6\
**Last updated:** [May 2, 2023, 10:11am UTC](https://discourse.julialang.org/t/plutonotebook-realtime-data-web-page-is-it-possible-or-do-we-head-for-python/98126 "2023-05-02T10:11:50Z")

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Hi there we have had a goal of 1 getting a real time data feed to update a data structure in a reliable manner. 2 use a notebook UI to effect the graphical representation of the the datastructure contents 3 allow 1 -…

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## [Computation termination](https://discourse.julialang.org/t/computation-termination/98046)

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**Author:** [@mst](https://discourse.julialang.org/u/mst)\
**Replies:** 18\
**Last updated:** [May 2, 2023, 9:35am UTC](https://discourse.julialang.org/t/computation-termination/98046 "2023-05-02T09:35:08Z")

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Hello, Say I run f(g(x)) where f has no method for a Nothing data type and where g is defined as: function g(x) if condition on x is true return a computed valid type for f end end f, therefore, will t…

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## [Change iteration variable](https://discourse.julialang.org/t/change-iteration-variable/98189)

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**Author:** [@Annaquest](https://discourse.julialang.org/u/Annaquest)\
**Replies:** 1\
**Last updated:** [May 2, 2023, 9:28am UTC](https://discourse.julialang.org/t/change-iteration-variable/98189 "2023-05-02T09:28:18Z")

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Hi, I get “t is not defined” when I do this: t = 1 while t \<= 200 println(t) if t == 1 println("Hei") elseif t == 140 t = 150 else println("Hei") end t += 1 end I can ma…

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## [Aqua.jl tests failing because Aqua not a dependency of root project](https://discourse.julialang.org/t/aqua-jl-tests-failing-because-aqua-not-a-dependency-of-root-project/83590)

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**Author:** [@maxkapur](https://discourse.julialang.org/u/maxkapur)\
**Replies:** 7\
**Last updated:** [May 2, 2023, 9:09am UTC](https://discourse.julialang.org/t/aqua-jl-tests-failing-because-aqua-not-a-dependency-of-root-project/83590 "2023-05-02T09:09:55Z")

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I’m trying to add Aqua.jl to my project. As suggested in the Aqua.jl documentation, I have placed Aqua in the test/Project.toml file to fix its version to 0.5. But now the Aqua tests fail if I call julia --project from m…

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## [How to fit ODE system only on one @variables](https://discourse.julialang.org/t/how-to-fit-ode-system-only-on-one-variables/97910)

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**Author:** [@fdekerme](https://discourse.julialang.org/u/fdekerme)\
**Replies:** 3\
**Last updated:** [May 2, 2023, 5:59am UTC](https://discourse.julialang.org/t/how-to-fit-ode-system-only-on-one-variables/97910 "2023-05-02T05:59:52Z")

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Hello, :grin: I have a small system of 2 differential equations whose @variables are N1 and N2, with 3 @parameters a, b, c. I have evolution data (experimental measurements) for the variable N1 only, named (time, data). …

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## [Earth as an ellipsoid](https://discourse.julialang.org/t/earth-as-an-ellipsoid/98147)

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**Author:** [@StevenSiew](https://discourse.julialang.org/u/StevenSiew)\
**Replies:** 6\
**Last updated:** [May 2, 2023, 4:08am UTC](https://discourse.julialang.org/t/earth-as-an-ellipsoid/98147 "2023-05-02T04:08:46Z")

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Hi everybody. I need help. I had model the planet Earth as a perfect sphere. Now I want to model planet Earth as an ellipsoid. However I got stump by a mystery. If Earth is an ellipsoid and I am standing at point P (s…

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## [Better way for plotting millions of scatter points in GLMakie](https://discourse.julialang.org/t/better-way-for-plotting-millions-of-scatter-points-in-glmakie/98127)

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**Author:** [@Gavin\_Held](https://discourse.julialang.org/u/Gavin_Held)\
**Replies:** 3\
**Last updated:** [May 2, 2023, 12:05am UTC](https://discourse.julialang.org/t/better-way-for-plotting-millions-of-scatter-points-in-glmakie/98127 "2023-05-02T00:05:41Z")

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Hello, I’ve been using Makie/GLMakie for about 2 years now, and am by no means an expert. I am mostly employing makie for its 3D plotting capabilities. Currently, I am trying to make 3D plots of plasma turbulence data …

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## [How to multiply differential of complex function with imaginary unit](https://discourse.julialang.org/t/how-to-multiply-differential-of-complex-function-with-imaginary-unit/98180)

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**Author:** [@Philip\_Stuckey](https://discourse.julialang.org/u/Philip_Stuckey)\
**Replies:** 0\
**Last updated:** [May 1, 2023, 11:30pm UTC](https://discourse.julialang.org/t/how-to-multiply-differential-of-complex-function-with-imaginary-unit/98180 "2023-05-01T23:30:08Z")

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I’m using Julia Version 1.8.5 Symbolics 5.3.1 and Pluto v0.19.25 version infoCommit 17cfb8e65ea (2023-01-08 06:45 UTC) Platform Info: OS: Linux (x86\_64-linux-gnu) CPU: 16 × AMD Ryzen 7 5800X 8-Core Processor WO…

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## [Convex.jl norm of multiple variables](https://discourse.julialang.org/t/convex-jl-norm-of-multiple-variables/98165)

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**Author:** [@ajd](https://discourse.julialang.org/u/ajd)\
**Replies:** 5\
**Last updated:** [May 1, 2023, 10:09pm UTC](https://discourse.julialang.org/t/convex-jl-norm-of-multiple-variables/98165 "2023-05-01T22:09:44Z")

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I would like to use Convex.jl to solve a problem along the lines of using Convex x = Variable(1) y = Variable(1) z = Variable(1) problem = minimize(x+y+z,norm(\[x,y,z\])\<=1) However, when I run this code, I get the error …

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## [What does it mean when yen\_k shows only one route?](https://discourse.julialang.org/t/what-does-it-mean-when-yen-k-shows-only-one-route/98132)

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**Author:** [@Yao\_Vang](https://discourse.julialang.org/u/Yao_Vang)\
**Replies:** 11\
**Last updated:** [May 1, 2023, 10:08pm UTC](https://discourse.julialang.org/t/what-does-it-mean-when-yen-k-shows-only-one-route/98132 "2023-05-01T22:08:31Z")

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Hello everyone, I’ve loaded a map via map = get\_map\_data(OSM\_File\_path, use\_cache=false, trim\_to\_connected\_graph=true) then randomly picked two nodeIDs to find out 5th shortest path between them. Since map.g stores a gr…

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## [Evaluating a MvNormal density with a sparse covariance matrix](https://discourse.julialang.org/t/evaluating-a-mvnormal-density-with-a-sparse-covariance-matrix/98173)

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**Author:** [@schwob](https://discourse.julialang.org/u/schwob)\
**Replies:** 1\
**Last updated:** [May 1, 2023, 9:09pm UTC](https://discourse.julialang.org/t/evaluating-a-mvnormal-density-with-a-sparse-covariance-matrix/98173 "2023-05-01T21:09:55Z")

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Suppose that Q is a sparse covariance matrix, and I want to evaluate \\mathbf{y} \\sim N(\\boldsymbol{0},Q). Can I leverage the sparsity of Q? Right now, I have Q as a SparseMatrixCSC{Float64, Int64}. Roughly 97% of the mat…

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## [Turing conditioning syntax and models using @addlogprob!](https://discourse.julialang.org/t/turing-conditioning-syntax-and-models-using-addlogprob/85196)

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**Author:** [@SebastianCallh](https://discourse.julialang.org/u/SebastianCallh)\
**Replies:** 6\
**Last updated:** [May 1, 2023, 8:55pm UTC](https://discourse.julialang.org/t/turing-conditioning-syntax-and-models-using-addlogprob/85196 "2023-05-01T20:55:49Z")

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Hello! It is my understanding the preferred syntax to provide observations to Turing models going forward is to make use of the condition operator model() | (;y) instead of explicitly passing the observations model(y). H…

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## [Julia v1.9.0-rc3 is now available](https://discourse.julialang.org/t/julia-v1-9-0-rc3-is-now-available/98176)

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**Author:** [@ararslan](https://discourse.julialang.org/u/ararslan)\
**Replies:** 0\
**Last updated:** [May 1, 2023, 8:42pm UTC](https://discourse.julialang.org/t/julia-v1-9-0-rc3-is-now-available/98176 "2023-05-01T20:42:37Z")

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The Julia developers are pleased to announce that v1.9.0-rc3, the third release candidate for the upcoming 1.9 stable series, is now available. Binaries are available for download at https://julialang.org/downloads in th…

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## [Export function-like objects](https://discourse.julialang.org/t/export-function-like-objects/98174)

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**Author:** [@rkube](https://discourse.julialang.org/u/rkube)\
**Replies:** 4\
**Last updated:** [May 1, 2023, 8:19pm UTC](https://discourse.julialang.org/t/export-function-like-objects/98174 "2023-05-01T20:19:43Z")

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Hi, in a custom module I’m defining function-like objects like this: export trf\_standardize struct trf\_standardize means stds end function (t::trf\_standardize)(x) (x .- t.means) ./ (t.stds) end How would…

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## [Unblocking auto-merge in general registry](https://discourse.julialang.org/t/unblocking-auto-merge-in-general-registry/40358)

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**Author:** [@krcools](https://discourse.julialang.org/u/krcools)\
**Replies:** 3\
**Last updated:** [May 1, 2023, 8:08pm UTC](https://discourse.julialang.org/t/unblocking-auto-merge-in-general-registry/40358 "2023-05-01T20:08:18Z")

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I have released a new version of a package using Registrator (web interface). One of the checks on JuliaRegistries failed (I needed to specify a compat range). In order for the PR not to be auto-merged in the meantime, I…

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## [Dimension mismatch in dataloader](https://discourse.julialang.org/t/dimension-mismatch-in-dataloader/98160)

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**Author:** [@jxxcarlson](https://discourse.julialang.org/u/jxxcarlson)\
**Replies:** 1\
**Last updated:** [May 1, 2023, 7:34pm UTC](https://discourse.julialang.org/t/dimension-mismatch-in-dataloader/98160 "2023-05-01T19:34:53Z")

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I have julia\> size(X\_train) (130, 4) julia\> size(y\_train) (130, 3) but I get a dimension mismatch with loader = Flux.DataLoader((X\_train, y\_train), shuffle=true) ((( Oops, I just need to transpose everything. )))

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## [\[ANN\] GraphsExt, features for possible inclusion in Graphs.jl](https://discourse.julialang.org/t/ann-graphsext-features-for-possible-inclusion-in-graphs-jl/98170)

<div class="topic-metadata">

**Author:** [@jlapeyre](https://discourse.julialang.org/u/jlapeyre)\
**Replies:** 5\
**Last updated:** [May 1, 2023, 6:33pm UTC](https://discourse.julialang.org/t/ann-graphsext-features-for-possible-inclusion-in-graphs-jl/98170 "2023-05-01T18:33:52Z")

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GraphsExt.jl implements some things that may eventually be added to Graphs.jl. I need to use them and want to expose them before making PRs to Graphs.jl. This package is not registered in the general registry but is in a…

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## [How to stringify a recursively constructed type](https://discourse.julialang.org/t/how-to-stringify-a-recursively-constructed-type/98143)

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**Author:** [@Niall](https://discourse.julialang.org/u/Niall)\
**Replies:** 2\
**Last updated:** [May 1, 2023, 6:19pm UTC](https://discourse.julialang.org/t/how-to-stringify-a-recursively-constructed-type/98143 "2023-05-01T18:19:31Z")

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I have defined a type representing a node in an execution tree. Sometimes it only contains a variable, sometimes it contains an operator and 1 or 2 arguments. Now I want to display it as a string by recursing down the tr…

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## [How to remove margin in single Makie plot](https://discourse.julialang.org/t/how-to-remove-margin-in-single-makie-plot/98169)

<div class="topic-metadata">

**Author:** [@LaurentPlagne](https://discourse.julialang.org/u/LaurentPlagne)\
**Replies:** 2\
**Last updated:** [May 1, 2023, 6:17pm UTC](https://discourse.julialang.org/t/how-to-remove-margin-in-single-makie-plot/98169 "2023-05-01T18:17:53Z")

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I would like to get rid of the surrounding white margin in the following Makie Plot. Any Idea ? using GLMakie nx,ny = 500,500 fig = Figure(resolution = (nx, ny), fontsize = 22) ax = Axis(fig\[1, 1\]; aspect = DataAspec…

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