# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1326

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

**Page:** 1327

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## [How to create a pre-compiler Julia image from C to reduce init time?](https://discourse.julialang.org/t/how-to-create-a-pre-compiler-julia-image-from-c-to-reduce-init-time/64930)

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**Author:** [@Clonkk](https://discourse.julialang.org/u/Clonkk)\
**Replies:** 0\
**Last updated:** [July 19, 2021, 3:30pm UTC](https://discourse.julialang.org/t/how-to-create-a-pre-compiler-julia-image-from-c-to-reduce-init-time/64930 "2021-07-19T15:30:36Z")

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Hello, I’ve been working on integratring Julia with Nim on GitHub - Clonkk/nimjl: A bridge between Nim-lang and Julia ! and I’d like to be able to save pre-compiled image and load them at start-up. For that I’m hoping …

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## [NLopt - Same complex clalculations in objetive function and nonlinear constraints](https://discourse.julialang.org/t/nlopt-same-complex-clalculations-in-objetive-function-and-nonlinear-constraints/41677)

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**Author:** [@wg030](https://discourse.julialang.org/u/wg030)\
**Replies:** 17\
**Last updated:** [July 19, 2021, 1:31pm UTC](https://discourse.julialang.org/t/nlopt-same-complex-clalculations-in-objetive-function-and-nonlinear-constraints/41677 "2021-07-19T13:31:52Z")

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Hey guys, I need a hint on how to effectivley solve a nonlinear optimization problem with NLopt package when my objective function contains some complex calculations and my nonlinear constraint contains the same complex…

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## [Turing.jl - Error running tutorial code](https://discourse.julialang.org/t/turing-jl-error-running-tutorial-code/64867)

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**Author:** [@v-i-s-h](https://discourse.julialang.org/u/v-i-s-h)\
**Replies:** 2\
**Last updated:** [July 19, 2021, 1:23pm UTC](https://discourse.julialang.org/t/turing-jl-error-running-tutorial-code/64867 "2021-07-19T13:23:54Z")

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I was try Turing.jl tutorial code for Bayesian Neural networks (Bayesian Neural Networks) When I try to run the Variational inference code (code below) using Bijectors using Turing: Variational using AdvancedVI m = ba…

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## [Trying to train a variable GNN w/ GeometricFlux.jl](https://discourse.julialang.org/t/trying-to-train-a-variable-gnn-w-geometricflux-jl/64246)

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**Author:** [@eahenle](https://discourse.julialang.org/u/eahenle)\
**Replies:** 4\
**Last updated:** [July 19, 2021, 1:23pm UTC](https://discourse.julialang.org/t/trying-to-train-a-variable-gnn-w-geometricflux-jl/64246 "2021-07-19T13:23:14Z")

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I am trying to train a gated graph neural network to predict molecular properties with GeometricFlux.jl: GitHub - FluxML/GeometricFlux.jl: Geometric Deep Learning for Flux The inputs are FeaturedGraph objects of various…

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## [Why does \`Flux.stack\` use splatting?](https://discourse.julialang.org/t/why-does-flux-stack-use-splatting/64923)

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**Author:** [@bad\_at\_math](https://discourse.julialang.org/u/bad_at_math)\
**Replies:** 1\
**Last updated:** [July 19, 2021, 1:12pm UTC](https://discourse.julialang.org/t/why-does-flux-stack-use-splatting/64923 "2021-07-19T13:12:49Z")

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The Flux.stack function is defined here: https://github.com/FluxML/Flux.jl/blob/b78a27b01c9629099adb059a98657b995760b617/src/utils.jl#L476, and it is very simple: stack(xs, dim) = cat(unsqueeze.(xs, dim)..., dims=dim). …

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## [Is there a name for an iterator that is like \`product(a, a)\` except only distinct-indexed elements are paired](https://discourse.julialang.org/t/is-there-a-name-for-an-iterator-that-is-like-product-a-a-except-only-distinct-indexed-elements-are-paired/64838)

<div class="topic-metadata">

**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 3\
**Last updated:** [July 19, 2021, 12:54pm UTC](https://discourse.julialang.org/t/is-there-a-name-for-an-iterator-that-is-like-product-a-a-except-only-distinct-indexed-elements-are-paired/64838 "2021-07-19T12:54:21Z")

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I often want to iterator over a iterable in such a way that distinct-index elements are only paired once. This is useful for things like one round round-robin leagues for i in 1:length(a)-1 for j in i+1:length(a) a…

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## [Compilation does not terminate (\>3 hours) with nested numerical integration](https://discourse.julialang.org/t/compilation-does-not-terminate-3-hours-with-nested-numerical-integration/64922)

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**Author:** [@meew0](https://discourse.julialang.org/u/meew0)\
**Replies:** 0\
**Last updated:** [July 19, 2021, 11:30am UTC](https://discourse.julialang.org/t/compilation-does-not-terminate-3-hours-with-nested-numerical-integration/64922 "2021-07-19T11:30:58Z")

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I am trying to do two-dimensional numerical integration. For this my first attempt was something like the following, using DoubleExponentialFormulas.jl. This example is significantly reduced and no longer does anything m…

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## [Julia Philosophical Direction](https://discourse.julialang.org/t/julia-philosophical-direction/64905)

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**Author:** [@blackeneth](https://discourse.julialang.org/u/blackeneth)\
**Replies:** 6\
**Last updated:** [July 19, 2021, 11:27am UTC](https://discourse.julialang.org/t/julia-philosophical-direction/64905 "2021-07-19T11:27:43Z")

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On the Julia homepage, the goals of Julia are stated as: Fast Composable (multiple dispatch) Dynamic General Reproducible Open Source Other informal goals would be “batteries included” (base has much of what you need)…

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## [Solving ODE with vector Argument](https://discourse.julialang.org/t/solving-ode-with-vector-argument/64907)

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**Author:** [@aiiiob\_bie](https://discourse.julialang.org/u/aiiiob_bie)\
**Replies:** 2\
**Last updated:** [July 19, 2021, 11:15am UTC](https://discourse.julialang.org/t/solving-ode-with-vector-argument/64907 "2021-07-19T11:15:54Z")

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Dear Friends I am trying to solve an ode problem function myfun(du,u,p,t) where u consists of the vectors x,z,e. I want this function return solution just for e (I do not know how must I do this) Here is the code whi…

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## [Failed to create new file](https://discourse.julialang.org/t/failed-to-create-new-file/64756)

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**Author:** [@assia855](https://discourse.julialang.org/u/assia855)\
**Replies:** 2\
**Last updated:** [July 19, 2021, 11:03am UTC](https://discourse.julialang.org/t/failed-to-create-new-file/64756 "2021-07-19T11:03:08Z")

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Hello folks, I need your help to write files with the same label as the input files. I calculate the number of characters in the input folder and insert it in the write function, but it doesn’t seem to work. It throws a…

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## [Where does the Atom editor (and others) store their Julia packages?](https://discourse.julialang.org/t/where-does-the-atom-editor-and-others-store-their-julia-packages/64894)

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**Author:** [@cybervigilante](https://discourse.julialang.org/u/cybervigilante)\
**Replies:** 4\
**Last updated:** [July 19, 2021, 10:57am UTC](https://discourse.julialang.org/t/where-does-the-atom-editor-and-others-store-their-julia-packages/64894 "2021-07-19T10:57:25Z")

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Finding stuff on Windows is a chore, and I have three different Julia installations. The basic REPL, the Jupyterlab installation, and Atom. Naturally, I’d like the same packages in all of them until I decide what to use …

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## [Streamplot statemap using JSServe](https://discourse.julialang.org/t/streamplot-statemap-using-jsserve/64337)

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**Author:** [@EvoArt](https://discourse.julialang.org/u/EvoArt)\
**Replies:** 13\
**Last updated:** [July 19, 2021, 10:52am UTC](https://discourse.julialang.org/t/streamplot-statemap-using-jsserve/64337 "2021-07-19T10:52:33Z")

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I’m trying to record a statemap to include an interactive streamplot in a web page. Is there a way to pull out the actual Float64 value from the observable? Thanks in advance. using WGLMakie, JSServe WGLMakie.activate!…

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## [Page size in Plots?](https://discourse.julialang.org/t/page-size-in-plots/64915)

<div class="topic-metadata">

**Author:** [@marianoarnaiz](https://discourse.julialang.org/u/marianoarnaiz)\
**Replies:** 2\
**Last updated:** [July 19, 2021, 10:19am UTC](https://discourse.julialang.org/t/page-size-in-plots/64915 "2021-07-19T10:19:19Z")

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Hi everyone. Not to be picky about Plots.jl, but comming from GMT and GMT.jl I am used to having a lot of flexibility when it comes to plotting (thans @joa-quim btw!). I am using plots heatmap and text keeps going outs…

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## [Strange performance characteristics and regression with tuple recursion](https://discourse.julialang.org/t/strange-performance-characteristics-and-regression-with-tuple-recursion/64888)

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**Author:** [@jfeist](https://discourse.julialang.org/u/jfeist)\
**Replies:** 5\
**Last updated:** [July 19, 2021, 10:14am UTC](https://discourse.julialang.org/t/strange-performance-characteristics-and-regression-with-tuple-recursion/64888 "2021-07-19T10:14:09Z")

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I have a custom iterator that produces the unique indices of an M-dimensional array with exchange symmetry (i.e., where the value is the same for any permutation of the indices), which is the same as the nonzero indices …

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## [Deploying docs to another repo with Github Actions](https://discourse.julialang.org/t/deploying-docs-to-another-repo-with-github-actions/64459)

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**Author:** [@tisztamo](https://discourse.julialang.org/u/tisztamo)\
**Replies:** 4\
**Last updated:** [July 19, 2021, 9:25am UTC](https://discourse.julialang.org/t/deploying-docs-to-another-repo-with-github-actions/64459 "2021-07-19T09:25:47Z")

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Trying to move a large-ish project with externally hosted documentation from Travis to Github Actions (It worked with Travis some time ago). deploydocs( repo = "github.com/Circo-dev/Circo-docs.git", branch = "ma…

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## [Undef to zeros?](https://discourse.julialang.org/t/undef-to-zeros/64871)

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**Author:** [@marianoarnaiz](https://discourse.julialang.org/u/marianoarnaiz)\
**Replies:** 4\
**Last updated:** [July 19, 2021, 9:08am UTC](https://discourse.julialang.org/t/undef-to-zeros/64871 "2021-07-19T09:08:13Z")

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Hi all. I have this array that was a lot info on it. Some of the cells in the matrix are "#undef " I want to write the file to ascii… any way to change all the #undef to zeros, or something? Thanks!

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## [Pluto vs. IJulia: Including a Local Module](https://discourse.julialang.org/t/pluto-vs-ijulia-including-a-local-module/64866)

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**Author:** [@TBulka](https://discourse.julialang.org/u/TBulka)\
**Replies:** 2\
**Last updated:** [July 19, 2021, 9:00am UTC](https://discourse.julialang.org/t/pluto-vs-ijulia-including-a-local-module/64866 "2021-07-19T09:00:04Z")

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Hello everyone, say, I have a small directory tree like this: +dir | +--subdir In subdir I have a file krkx.jl which just contains a simple module: module Krkx export superfunc function superfunc(x, y) x + y - …

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## [Structuring a Type with Exception Messages](https://discourse.julialang.org/t/structuring-a-type-with-exception-messages/62127)

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**Author:** [@ptoche](https://discourse.julialang.org/u/ptoche)\
**Replies:** 7\
**Last updated:** [July 19, 2021, 8:57am UTC](https://discourse.julialang.org/t/structuring-a-type-with-exception-messages/62127 "2021-07-19T08:57:01Z")

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I’m new to struct and have found parametric types a bit difficult to understand. I would like to constrain the admissible types and fail gracefully with intelligible messages. For instance, let’s say I only want to admi…

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## [Recipe to plot simple dataframes](https://discourse.julialang.org/t/recipe-to-plot-simple-dataframes/64889)

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**Author:** [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Replies:** 7\
**Last updated:** [July 19, 2021, 7:57am UTC](https://discourse.julialang.org/t/recipe-to-plot-simple-dataframes/64889 "2021-07-19T07:57:22Z")

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Looking for a default recipe for plotting simple dataframes with plot(df). Two questions: Does such recipe currently exist? Is something like the code snippet below a valid Plots’ recipe? using DataFrames, Plots; gr(…

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## [No plot with CairoMakie](https://discourse.julialang.org/t/no-plot-with-cairomakie/64914)

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**Author:** [@mzaffalon](https://discourse.julialang.org/u/mzaffalon)\
**Replies:** 3\
**Last updated:** [July 19, 2021, 7:42am UTC](https://discourse.julialang.org/t/no-plot-with-cairomakie/64914 "2021-07-19T07:42:27Z")

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I have tried the tutorial and I do not see any plot under Windows 10 julia\> using CairoMakie julia\> x = range(0, 10, length=100); julia\> y = sin.(x); julia\> lines(x, y) Scene (800px, 600px): 18 Plots: ├ Poly{Tuple…

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## [Handling a "Mixed Type" Matrix (String, Float64 and Int64)](https://discourse.julialang.org/t/handling-a-mixed-type-matrix-string-float64-and-int64/64910)

<div class="topic-metadata">

**Author:** [@Peter-Jolly](https://discourse.julialang.org/u/Peter-Jolly)\
**Replies:** 2\
**Last updated:** [July 19, 2021, 7:18am UTC](https://discourse.julialang.org/t/handling-a-mixed-type-matrix-string-float64-and-int64/64910 "2021-07-19T07:18:20Z")

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I am trying to copy a string vector into a numerical matrix (2D) column and having some difficulty. I realise Julia one needs to take note on how to define the matrix type. Please see my simple test example below. The co…

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## [Compiler and run-time engineer at Julia Computing](https://discourse.julialang.org/t/compiler-and-run-time-engineer-at-julia-computing/64386)

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**Author:** [@jeff.bezanson](https://discourse.julialang.org/u/jeff.bezanson)\
**Replies:** 1\
**Last updated:** [July 11, 2021, 4:36am UTC](https://discourse.julialang.org/t/compiler-and-run-time-engineer-at-julia-computing/64386 "2021-07-11T04:36:59Z")

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Julia Computing is seeking a Compiler and Run-time System Engineer to contribute to the core technology in the Julia programming language. You will work closely with maintainers of the Julia open-source project on implem…

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## [Using CuArrays with Iterators.product()](https://discourse.julialang.org/t/using-cuarrays-with-iterators-product/64824)

<div class="topic-metadata">

**Author:** [@gregory](https://discourse.julialang.org/u/gregory)\
**Replies:** 1\
**Last updated:** [July 19, 2021, 6:24am UTC](https://discourse.julialang.org/t/using-cuarrays-with-iterators-product/64824 "2021-07-19T06:24:34Z")

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Hello, I am trying to port some CPU code to GPUs where I run over a high-dimensional array and perform some operations. Below is a MWE of what I am doing on the CPU: function sequential\_rand!(x, test) for i in Ite…

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## [Julia Source Code Directory](https://discourse.julialang.org/t/julia-source-code-directory/64904)

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**Author:** [@Nelson\_Chow](https://discourse.julialang.org/u/Nelson_Chow)\
**Replies:** 4\
**Last updated:** [July 19, 2021, 5:32am UTC](https://discourse.julialang.org/t/julia-source-code-directory/64904 "2021-07-19T05:32:53Z")

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Hi, I am new to Julia, previously work primarily on VBA, a little C++, Matlab and Python. This is literally my second Julia Script after Hello World. I was wondering (and i have searched on google and this forum alread…

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## [Reading data text files delimited with both spaces & tabs](https://discourse.julialang.org/t/reading-data-text-files-delimited-with-both-spaces-tabs/64851)

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**Author:** [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Replies:** 13\
**Last updated:** [July 19, 2021, 4:54am UTC](https://discourse.julialang.org/t/reading-data-text-files-delimited-with-both-spaces-tabs/64851 "2021-07-19T04:54:14Z")

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Is it possible in CSV.jl, DelimitedFiles.jl, or other, to read text files that contain both spaces & tabs, in the header and/or data sections? An example is provided below. NB: the hidden spaces and tabs should be ther…

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## [Is \`using Package: function\` supposed to save precompile time, or just prevent namespace collisions?](https://discourse.julialang.org/t/is-using-package-function-supposed-to-save-precompile-time-or-just-prevent-namespace-collisions/64898)

<div class="topic-metadata">

**Author:** [@maxkapur](https://discourse.julialang.org/u/maxkapur)\
**Replies:** 1\
**Last updated:** [July 19, 2021, 4:50am UTC](https://discourse.julialang.org/t/is-using-package-function-supposed-to-save-precompile-time-or-just-prevent-namespace-collisions/64898 "2021-07-19T04:50:09Z")

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I often import a package even though I am only planning on using one or two functions from it: julia\> @time using Distributions 1.420353 seconds (1.77 M allocations: 113.360 MiB, 0.27% compilation time) I am thinking…

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## [Customizing deplpydocs commit name?](https://discourse.julialang.org/t/customizing-deplpydocs-commit-name/64766)

<div class="topic-metadata">

**Author:** [@orome](https://discourse.julialang.org/u/orome)\
**Replies:** 1\
**Last updated:** [July 19, 2021, 3:37am UTC](https://discourse.julialang.org/t/customizing-deplpydocs-commit-name/64766 "2021-07-19T03:37:20Z")

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Is there a way to customize the name of the commit generated by Documenter.deploydocs()?

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## [Just curious about a code in Base](https://discourse.julialang.org/t/just-curious-about-a-code-in-base/64893)

<div class="topic-metadata">

**Author:** [@josePereiro](https://discourse.julialang.org/u/josePereiro)\
**Replies:** 7\
**Last updated:** [July 19, 2021, 3:16am UTC](https://discourse.julialang.org/t/just-curious-about-a-code-in-base/64893 "2021-07-19T03:16:04Z")

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Hi, I was hanging around Base and I found this method. @edit Base.hash\_32\_32(UInt32(1)) # juila 1.6.1 function hash\_32\_32(n::UInt32) a::UInt32 = n # what is it the purpose of this line? a = a + 0x7ed55d16 + a \<\<…

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## [Could separating private attribute access help performance?](https://discourse.julialang.org/t/could-separating-private-attribute-access-help-performance/64881)

<div class="topic-metadata">

**Author:** [@jzr](https://discourse.julialang.org/u/jzr)\
**Replies:** 2\
**Last updated:** [July 19, 2021, 2:58am UTC](https://discourse.julialang.org/t/could-separating-private-attribute-access-help-performance/64881 "2021-07-19T02:58:10Z")

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Suppose Julia distinguished between private and public attributes struct Foo @public u a b end so that public access x.u was allowed but access to private attributes from outside the module needed getprivate(x, …

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## [JuliaCon 2021 T-shirts and Stickers on Sale Now!](https://discourse.julialang.org/t/juliacon-2021-t-shirts-and-stickers-on-sale-now/62060)

<div class="topic-metadata">

**Author:** [@logankilpatrick](https://discourse.julialang.org/u/logankilpatrick)\
**Replies:** 52\
**Last updated:** [July 19, 2021, 2:16am UTC](https://discourse.julialang.org/t/juliacon-2021-t-shirts-and-stickers-on-sale-now/62060 "2021-07-19T02:16:40Z")

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Hey all, this year’s Limited Edition JuliaCon 2021 T-shirts are now on sale! We kept the classic look: JuliaCon 2021 Shirts | Bonfire but also added a new design this year: JuliaCon 2021 REPL Shirt | Bonfire. Additionall…

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