# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1629

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

**Page:** 1630

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## [JuliaCon 2020 BoF Session: Transitioning Code From Closed To Open](https://discourse.julialang.org/t/juliacon-2020-bof-session-transitioning-code-from-closed-to-open/43504)

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**Author:** [@jrevels](https://discourse.julialang.org/u/jrevels)\
**Replies:** 3\
**Last updated:** [September 16, 2020, 9:36pm UTC](https://discourse.julialang.org/t/juliacon-2020-bof-session-transitioning-code-from-closed-to-open/43504 "2020-09-16T21:36:11Z")

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Hi all, I’ll be running a JuliaCon BoF session next Friday wherein we’ll discuss challenges, strategies, and opportunities related to open-sourcing code from within private organizations. The basic premise: Within pri…

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## [How to select half the rows from a DataFrame column and return an array of values from another column](https://discourse.julialang.org/t/how-to-select-half-the-rows-from-a-dataframe-column-and-return-an-array-of-values-from-another-column/46486)

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**Author:** [@yold6](https://discourse.julialang.org/u/yold6)\
**Replies:** 2\
**Last updated:** [September 16, 2020, 9:25pm UTC](https://discourse.julialang.org/t/how-to-select-half-the-rows-from-a-dataframe-column-and-return-an-array-of-values-from-another-column/46486 "2020-09-16T21:25:09Z")

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Hi all, I would like to know how one might partition unique string values from one column of the DataFrame (C) to achieve my goal. using Random, DataFrames C = DataFrame(Team = \["Packers", "Knights", "Bills", "Falcons"…

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## [Package similar to Ludwig](https://discourse.julialang.org/t/package-similar-to-ludwig/46731)

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**Author:** [@ludovic\_chauveau](https://discourse.julialang.org/u/ludovic_chauveau)\
**Replies:** 0\
**Last updated:** [September 16, 2020, 9:08pm UTC](https://discourse.julialang.org/t/package-similar-to-ludwig/46731 "2020-09-16T21:08:44Z")

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Hi peeps, From long time ago I things do a solution to easily use ML & Deep Learning with Julia but I’m a newby in this domain. So I make research of No-Code / Low-Code AI / ML… I just found an existing open source pro…

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## [Tiered dispatch algebra](https://discourse.julialang.org/t/tiered-dispatch-algebra/45866)

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**Author:** [@chakravala](https://discourse.julialang.org/u/chakravala)\
**Replies:** 13\
**Last updated:** [September 16, 2020, 9:17pm UTC](https://discourse.julialang.org/t/tiered-dispatch-algebra/45866 "2020-09-16T21:17:06Z")

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In my experience, I have programmed a lot of algebra in the Julia language (created Dendriform.jl, Reduce.jl, Grassmann.jl). Here’s a question: In my experiences with algebra dispatch in Julia, the combinatorial explosi…

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## [MixedModels.jl: how to get confidence intervals?](https://discourse.julialang.org/t/mixedmodels-jl-how-to-get-confidence-intervals/46730)

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**Author:** [@kai](https://discourse.julialang.org/u/kai)\
**Replies:** 0\
**Last updated:** [September 16, 2020, 9:06pm UTC](https://discourse.julialang.org/t/mixedmodels-jl-how-to-get-confidence-intervals/46730 "2020-09-16T21:06:17Z")

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Hi, I wonder how to get confidence intervals for fixed effect parameters \\beta after fitting a LMM using MixedModels.jl? Are Wald-type intervals the only option at the moment? With lme4 in R, I usually use confint(metho…

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## [Optimization errors with simple JuMP function using GLPK Optimizer](https://discourse.julialang.org/t/optimization-errors-with-simple-jump-function-using-glpk-optimizer/46652)

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**Author:** [@standon41](https://discourse.julialang.org/u/standon41)\
**Replies:** 9\
**Last updated:** [September 16, 2020, 8:53pm UTC](https://discourse.julialang.org/t/optimization-errors-with-simple-jump-function-using-glpk-optimizer/46652 "2020-09-16T20:53:07Z")

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Hello, I am a novice to Julia programming. Going though a tutorial I see myself running into this error and I am not quite sure what it means. Can someone who is an expert in JuMP and GLPK advise? Error: MethodError: …

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## [Using optimizer callbacks within JuMP to terminate MIP solve](https://discourse.julialang.org/t/using-optimizer-callbacks-within-jump-to-terminate-mip-solve/46679)

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**Author:** [@adow031](https://discourse.julialang.org/u/adow031)\
**Replies:** 5\
**Last updated:** [September 16, 2020, 8:23pm UTC](https://discourse.julialang.org/t/using-optimizer-callbacks-within-jump-to-terminate-mip-solve/46679 "2020-09-16T20:23:57Z")

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I’ve got a MIP problem in JuMP, for which I would like the branch-and-bound to terminate as soon as the incumbent reaches a particular value, or as soon as the lower bound reaches a (different) particular value. I’ve fo…

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## [Using union() and list comprehesions](https://discourse.julialang.org/t/using-union-and-list-comprehesions/46727)

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**Author:** [@asavasci](https://discourse.julialang.org/u/asavasci)\
**Replies:** 2\
**Last updated:** [September 16, 2020, 8:11pm UTC](https://discourse.julialang.org/t/using-union-and-list-comprehesions/46727 "2020-09-16T20:11:41Z")

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I have two-element array whose elements are Sets, x = \[ Set(\[:a,:b,:c\]), Set(\[:c\]) \], I would like to make union of the array elements as one resulting set, Set(\[:a, :b, :c\]). I am having issue with union and iterate us…

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## [Community chat 09/20 10 EST](https://discourse.julialang.org/t/community-chat-09-20-10-est/46417)

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**Author:** [@McCoy](https://discourse.julialang.org/u/McCoy)\
**Replies:** 10\
**Last updated:** [September 16, 2020, 7:58pm UTC](https://discourse.julialang.org/t/community-chat-09-20-10-est/46417 "2020-09-16T19:58:45Z")

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Please post topics of interest here.

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## [Slow compile time with a lot of keyword arguments](https://discourse.julialang.org/t/slow-compile-time-with-a-lot-of-keyword-arguments/46677)

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**Author:** [@Ronis\_BR](https://discourse.julialang.org/u/Ronis_BR)\
**Replies:** 10\
**Last updated:** [September 16, 2020, 7:15pm UTC](https://discourse.julialang.org/t/slow-compile-time-with-a-lot-of-keyword-arguments/46677 "2020-09-16T19:15:28Z")

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Hi! My package PrettyTables.jl started to have a lot of configuration possibilities, which are handle by keyword arguments like: function \_pt\_text(io::IO, pinfo::PrintInfo; border\_crayon::Crayon = Cra…

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## [Outdated example for Plots' "surface" command](https://discourse.julialang.org/t/outdated-example-for-plots-surface-command/35219)

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**Author:** [@TheLateKronos](https://discourse.julialang.org/u/TheLateKronos)\
**Replies:** 14\
**Last updated:** [September 16, 2020, 6:48pm UTC](https://discourse.julialang.org/t/outdated-example-for-plots-surface-command/35219 "2020-09-16T18:48:32Z")

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When I type “?surface” into the REPL, I get the following: ... Example ≡≡≡≡≡≡≡≡≡ julia\> x = y = range(-3, 3, length = 100) julia\> surface(x, y, (x, y) -\> sinc(norm(\[x, y\]))) This example generates the following erro…

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## [ANN: GXBeam.jl](https://discourse.julialang.org/t/ann-gxbeam-jl/46591)

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**Author:** [@taylormcd](https://discourse.julialang.org/u/taylormcd)\
**Replies:** 16\
**Last updated:** [September 15, 2020, 9:39pm UTC](https://discourse.julialang.org/t/ann-gxbeam-jl/46591 "2020-09-15T21:39:10Z")

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Announcing GXBeam.jl This package provides an thoroughly verified and validated implementation of geometrically exact beam theory written in pure Julia. It’s also extremely fast, rivaling Fortran implementations of geo…

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## [Using ArchGDAL](https://discourse.julialang.org/t/using-archgdal/46006)

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**Author:** [@Ordens\_Ritter](https://discourse.julialang.org/u/Ordens_Ritter)\
**Replies:** 13\
**Last updated:** [September 16, 2020, 5:43pm UTC](https://discourse.julialang.org/t/using-archgdal/46006 "2020-09-16T17:43:48Z")

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Hi, I wanted, to give Julia a chance because it said to be rather fast. And some parts of my Python code needs hours (like 3 to 5) and that just to much, to be productively useful. Especial when you still have to debug …

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## [Poor performance with custom multidimensional iterator](https://discourse.julialang.org/t/poor-performance-with-custom-multidimensional-iterator/46529)

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**Author:** [@benninkrs](https://discourse.julialang.org/u/benninkrs)\
**Replies:** 4\
**Last updated:** [September 16, 2020, 5:48pm UTC](https://discourse.julialang.org/t/poor-performance-with-custom-multidimensional-iterator/46529 "2020-09-16T17:48:22Z")

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I am trying to implement a custom iterator for multidimensional arrays, which among other things, allows one to specify the order in which the axes are iterated. Sadly, I am having trouble getting even close to the perfo…

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## [\[ANN\] DiscreteEvents 0.3: discrete event generation and simulation](https://discourse.julialang.org/t/ann-discreteevents-0-3-discrete-event-generation-and-simulation/46477)

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**Author:** [@pbayer](https://discourse.julialang.org/u/pbayer)\
**Replies:** 1\
**Last updated:** [September 16, 2020, 4:03pm UTC](https://discourse.julialang.org/t/ann-discreteevents-0-3-discrete-event-generation-and-simulation/46477 "2020-09-16T16:03:35Z")

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A Julia package for discrete event generation and simulation I’m pleased to announce that DiscreteEvents 0.3 is now available from the Julia registry. It has been renamed from Simulate 0.2 following the discussion on Di…

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## [Dictionary](https://discourse.julialang.org/t/dictionary/46711)

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**Author:** [@mmyousefies](https://discourse.julialang.org/u/mmyousefies)\
**Replies:** 2\
**Last updated:** [September 16, 2020, 4:23pm UTC](https://discourse.julialang.org/t/dictionary/46711 "2020-09-16T16:23:11Z")

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hello, I’m new to Julia, and here’s my problem: using RDatasets, I wanted to make a dictionary of the first 2columns of the “iris” data frame; here’s how I did it: using RDataets IRIS = dataset(“datasets”,“iris”) j …

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## [Using the iteration interface with custom indices](https://discourse.julialang.org/t/using-the-iteration-interface-with-custom-indices/46600)

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**Author:** [@jlchan](https://discourse.julialang.org/u/jlchan)\
**Replies:** 10\
**Last updated:** [September 16, 2020, 4:17pm UTC](https://discourse.julialang.org/t/using-the-iteration-interface-with-custom-indices/46600 "2020-09-16T16:17:09Z")

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I’m a bit confused on how to use iteration utilities with a custom index set. I tried a MWE (just reproducing a for loop) as follows: struct CustomIndex i::Int end struct CustomIndexSet n::Int end Base.iterate…

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## [What are lower bounds for types?](https://discourse.julialang.org/t/what-are-lower-bounds-for-types/46712)

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**Author:** [@astadmistry](https://discourse.julialang.org/u/astadmistry)\
**Replies:** 9\
**Last updated:** [September 16, 2020, 4:03pm UTC](https://discourse.julialang.org/t/what-are-lower-bounds-for-types/46712 "2020-09-16T16:03:43Z")

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I’m trying to understand what lower bounds are for types. I ran the following code which shows which subtypes (recursively) of number satisfies/rejects Int \<: T \<: Real in hope of gaining an understanding, however I’m st…

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## [Reduce and sum Value ( frequency matrix)](https://discourse.julialang.org/t/reduce-and-sum-value-frequency-matrix/46687)

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**Author:** [@JohnFlorez25](https://discourse.julialang.org/u/JohnFlorez25)\
**Replies:** 3\
**Last updated:** [September 16, 2020, 3:35pm UTC](https://discourse.julialang.org/t/reduce-and-sum-value-frequency-matrix/46687 "2020-09-16T15:35:18Z")

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Hello, I have a Dataframe with a frequency matrix generate about events in relation to a user. I need to reduce this matrix in unique USER\_ID and sum each EVENT CATEGORY - events categories correspond to category 1,2…

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## [Iterate with 1:N is faster than 1:length(A)](https://discourse.julialang.org/t/iterate-with-1-n-is-faster-than-1-length-a/46664)

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**Author:** [@stakaz](https://discourse.julialang.org/u/stakaz)\
**Replies:** 12\
**Last updated:** [September 16, 2020, 3:17pm UTC](https://discourse.julialang.org/t/iterate-with-1-n-is-faster-than-1-length-a/46664 "2020-09-16T15:17:43Z")

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Hello, I am about to benchmark different ways of iterate over an array and I have realized a strange thing (I am on julia 1.5.1) The following test: julia\> using BenchmarkTools julia\> function N\_iterator(A, N) …

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## [Suppress non-julia console output](https://discourse.julialang.org/t/suppress-non-julia-console-output/46593)

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**Author:** [@Luapulu](https://discourse.julialang.org/u/Luapulu)\
**Replies:** 10\
**Last updated:** [September 16, 2020, 3:13pm UTC](https://discourse.julialang.org/t/suppress-non-julia-console-output/46593 "2020-09-16T15:13:35Z")

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I’m calling c code from julia, which prints to console when it is run. I’d like to not see these print statements. How do I do that? The Suppressor.@suppress\_out macro doesn’t work in this case.

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## [REPL and for loops (scope behavior change)](https://discourse.julialang.org/t/repl-and-for-loops-scope-behavior-change/13514)

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**Author:** [@saschatimme](https://discourse.julialang.org/u/saschatimme)\
**Replies:** 42\
**Last updated:** [September 16, 2020, 2:57pm UTC](https://discourse.julialang.org/t/repl-and-for-loops-scope-behavior-change/13514 "2020-09-16T14:57:08Z")

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In the REPL, to test some code, I often do things like julia\> a = 0 0 julia\> for i=1:3 a+=i end But under Julia 1.0 this will now throw an error ERROR: UndefVarError: a not defined Stacktrace: \[1\] …

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## [How to merge new package?](https://discourse.julialang.org/t/how-to-merge-new-package/46693)

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**Author:** [@Johncowk](https://discourse.julialang.org/u/Johncowk)\
**Replies:** 3\
**Last updated:** [September 16, 2020, 2:54pm UTC](https://discourse.julialang.org/t/how-to-merge-new-package/46693 "2020-09-16T14:54:55Z")

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This might seem like a dumb question but since I don’t know anyone I could ask I’ll do it here. I made a new package which couldn’t be automatically merged to the registry because it wasn’t fullfilling some requirements…

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## [PSA: pin Revise at 2](https://discourse.julialang.org/t/psa-pin-revise-at-2/44412)

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**Author:** [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Replies:** 4\
**Last updated:** [September 16, 2020, 2:46pm UTC](https://discourse.julialang.org/t/psa-pin-revise-at-2/44412 "2020-09-16T14:46:52Z")

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Update: now that Revise 3 has been released, this is no longer necessary. Just use fully-updated packages. Several folks are having Revise problems that stem from Pkg installing a very old Revise version. You can fix it…

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## [\[ANN\] Revise 3.0: faster and better](https://discourse.julialang.org/t/ann-revise-3-0-faster-and-better/46287)

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**Author:** [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Replies:** 12\
**Last updated:** [September 16, 2020, 2:43pm UTC](https://discourse.julialang.org/t/ann-revise-3-0-faster-and-better/46287 "2020-09-16T14:43:38Z")

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I’m pleased to announce that Revise 3.0 is available for beta-testing on Julia 1.0, 1.5, and nightly. Switch to it by updating your packages. (EDIT: this was originally written when Revise 3 was in beta but it is now rel…

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## [Variance, std where is now ? in 1.5.1 verision?](https://discourse.julialang.org/t/variance-std-where-is-now-in-1-5-1-verision/46699)

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**Author:** [@programista](https://discourse.julialang.org/u/programista)\
**Replies:** 2\
**Last updated:** [September 16, 2020, 2:41pm UTC](https://discourse.julialang.org/t/variance-std-where-is-now-in-1-5-1-verision/46699 "2020-09-16T14:41:42Z")

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Where in 1.5.1 versio is variance , std ? Version 1.5.1 (2020-08-25) julia\> a = rand(10) 10-element Array{Float64,1}: 0.31820694853200404 0.19056834277810242 0.7491023037833544 0.013571726580821286 0.891972776929…

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## [Why isn't a patch version allowed to narrow supported Julia versions?](https://discourse.julialang.org/t/why-isnt-a-patch-version-allowed-to-narrow-supported-julia-versions/46701)

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**Author:** [@galenlynch](https://discourse.julialang.org/u/galenlynch)\
**Replies:** 10\
**Last updated:** [September 16, 2020, 2:14pm UTC](https://discourse.julialang.org/t/why-isnt-a-patch-version-allowed-to-narrow-supported-julia-versions/46701 "2020-09-16T14:14:24Z")

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I’ve never understood why this rule is enforced in the General registry, e.g. here. If a package changes in no other way than narrowing supported versions of Julia, that is to say that no new functionality is introduced …

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## [Failed to precompile ORCA](https://discourse.julialang.org/t/failed-to-precompile-orca/46494)

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**Author:** [@zlq178](https://discourse.julialang.org/u/zlq178)\
**Replies:** 15\
**Last updated:** [September 16, 2020, 2:07pm UTC](https://discourse.julialang.org/t/failed-to-precompile-orca/46494 "2020-09-16T14:07:16Z")

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"’ using Plots,PlotlyJS x=\[1:10\] y=rand(10) z=rand(10) plot(x,y,z) plotlyjs() ‘’’ Error:Failed to precompile ORCA \[47be7bcc-f1a6-5447-8b36-7eeeff7534fd\] to C:\\Users\\zlq.juliapro\\JuliaPro\_v1.4.2-1\\compiled\\v1.4\\OR…

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## [How do I make @progress and @animate play nice together?](https://discourse.julialang.org/t/how-do-i-make-progress-and-animate-play-nice-together/22760)

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**Author:** [@DrPapa](https://discourse.julialang.org/u/DrPapa)\
**Replies:** 2\
**Last updated:** [September 16, 2020, 1:27pm UTC](https://discourse.julialang.org/t/how-do-i-make-progress-and-animate-play-nice-together/22760 "2020-09-16T13:27:48Z")

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I am creating some gifs using the @animate macro in Plots.jl that are time consuming to make. I would like to display the progress with Juno.@progress. Unfortunately, stacking the two doesn’t work directly, e.g. using J…

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## [Gabor Kernel](https://discourse.julialang.org/t/gabor-kernel/46380)

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**Author:** [@rickybblock](https://discourse.julialang.org/u/rickybblock)\
**Replies:** 8\
**Last updated:** [September 16, 2020, 12:32pm UTC](https://discourse.julialang.org/t/gabor-kernel/46380 "2020-09-16T12:32:07Z")

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Hi, I’m trying to create and visualize a Gabor kernel. First I used Kernel.gabor from ImageFiltering.jl and it worked, I think (I still have to learn how to use it to convolve with an image, but okay). gabor = Kernel.…

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