# Latest

**URL:** https://discourse.julialang.org/latest.md?page=838

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

**Page:** 839

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## [Julia Sympy Apply To Both Sides Of Equation](https://discourse.julialang.org/t/julia-sympy-apply-to-both-sides-of-equation/91514)

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**Author:** [@Brian\_Toomey](https://discourse.julialang.org/u/Brian_Toomey)\
**Replies:** 10\
**Last updated:** [December 13, 2022, 3:25pm UTC](https://discourse.julialang.org/t/julia-sympy-apply-to-both-sides-of-equation/91514 "2022-12-13T15:25:46Z")

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Julia Sympy is great! Many thanks to the people that worked on it. I’m wondering about how one might implement a strategy like the one described here so that I could work through calculations myself for problem sets. T…

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## [Solve problems starting from corresponding .nl files](https://discourse.julialang.org/t/solve-problems-starting-from-corresponding-nl-files/91306)

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**Author:** [@Luca](https://discourse.julialang.org/u/Luca)\
**Replies:** 7\
**Last updated:** [December 13, 2022, 10:03am UTC](https://discourse.julialang.org/t/solve-problems-starting-from-corresponding-nl-files/91306 "2022-12-13T10:03:15Z")

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Dear all, I want to solve a bunch of nonlinear optimization problems, whose nl. files are available. Hence I would like to charge the .nl files directly in Julia and solve the corresponding problem with a nonlinear solv…

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## [Senior Developer Advocate @ Genie (Remote)](https://discourse.julialang.org/t/senior-developer-advocate-genie-remote/86860)

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**Author:** [@CiPa](https://discourse.julialang.org/u/CiPa)\
**Replies:** 2\
**Last updated:** [December 13, 2022, 2:09pm UTC](https://discourse.julialang.org/t/senior-developer-advocate-genie-remote/86860 "2022-12-13T14:09:36Z")

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Hi! At Genie we’re looking for an experienced Developer Advocate to join our core team. More info here: https://www.linkedin.com/jobs/view/3239145593/

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## [Strided convolutions](https://discourse.julialang.org/t/strided-convolutions/91603)

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**Author:** [@cvikas](https://discourse.julialang.org/u/cvikas)\
**Replies:** 0\
**Last updated:** [December 13, 2022, 1:41pm UTC](https://discourse.julialang.org/t/strided-convolutions/91603 "2022-12-13T13:41:53Z")

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Hi everyone, Is there a package that facilitates strided convolution with user specific filter. I see that there is an implementation in Flux.jl, but I would like to use it s a function with the given stride and filter …

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## [In the emacs vterm, dark\_gray color appears to be displayed as black and DataFrame border lines are broken](https://discourse.julialang.org/t/in-the-emacs-vterm-dark-gray-color-appears-to-be-displayed-as-black-and-dataframe-border-lines-are-broken/91599)

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**Author:** [@Sijun](https://discourse.julialang.org/u/Sijun)\
**Replies:** 0\
**Last updated:** [December 13, 2022, 12:46pm UTC](https://discourse.julialang.org/t/in-the-emacs-vterm-dark-gray-color-appears-to-be-displayed-as-black-and-dataframe-border-lines-are-broken/91599 "2022-12-13T12:46:47Z")

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As shown below: My emacs GUI is launched from WSL2. If I run vterm from an emacs terminal (emacs -nw), besides the color issue, the border lines of the DataFrame become broken. as show below: How can I fix this …

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## [Compat entry for non-dependency](https://discourse.julialang.org/t/compat-entry-for-non-dependency/91590)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 2\
**Last updated:** [December 13, 2022, 12:16pm UTC](https://discourse.julialang.org/t/compat-entry-for-non-dependency/91590 "2022-12-13T12:16:34Z")

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In the Project.toml of package A, I would like to restrict compatibility for package B that is not a dependency. (why I am doing this)The motivation is following up on an array index ordering change of MCMCDiagnosticToo…

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## [Typed globals: macro to define multiple, without manual type annotations](https://discourse.julialang.org/t/typed-globals-macro-to-define-multiple-without-manual-type-annotations/90818)

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**Author:** [@tfiers](https://discourse.julialang.org/u/tfiers)\
**Replies:** 9\
**Last updated:** [December 13, 2022, 12:01pm UTC](https://discourse.julialang.org/t/typed-globals-macro-to-define-multiple-without-manual-type-annotations/90818 "2022-12-13T12:01:00Z")

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I vaguely remember seeing a macro somewhere to define typed globals without having to give the type explicitly, something like @typed begin a = 2 b = 2.8 ⋮ end which would expand to a::Int = 2 b::Float64 = 2.8 ⋮…

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## [Why I cannot use a tuple in \`map\` directly?](https://discourse.julialang.org/t/why-i-cannot-use-a-tuple-in-map-directly/91575)

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**Author:** [@pitsianis](https://discourse.julialang.org/u/pitsianis)\
**Replies:** 4\
**Last updated:** [December 13, 2022, 11:43am UTC](https://discourse.julialang.org/t/why-i-cannot-use-a-tuple-in-map-directly/91575 "2022-12-13T11:43:35Z")

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Why I cannot do this map((i,j,v) -\> v/(i\*j), zip(\[1,2\],\[10,20\],\[100,200\])) But this is just fine \[v/(i\*j) for (i,j,v) in zip(\[1,2\],\[10,20\],\[100,200\])\] And instead I have to write map(x -\> x\[3\]/(x\[1\]\*x\[2\]), zip(\[1,2\]…

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## [Count occurances for matrix rows (where column order does not matter)](https://discourse.julialang.org/t/count-occurances-for-matrix-rows-where-column-order-does-not-matter/91374)

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**Author:** [@KevinMoerman](https://discourse.julialang.org/u/KevinMoerman)\
**Replies:** 30\
**Last updated:** [December 13, 2022, 11:18am UTC](https://discourse.julialang.org/t/count-occurances-for-matrix-rows-where-column-order-does-not-matter/91374 "2022-12-13T11:18:53Z")

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I would like to detect rows in a matrix which only occur once, also the column order does not matter. This relates to this discussion. I have implemented several options (see below), and all work (note though I am a Jul…

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## [Why am I copying?](https://discourse.julialang.org/t/why-am-i-copying/91592)

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**Author:** [@f.ij](https://discourse.julialang.org/u/f.ij)\
**Replies:** 2\
**Last updated:** [December 13, 2022, 10:50am UTC](https://discourse.julialang.org/t/why-am-i-copying/91592 "2022-12-13T10:50:31Z")

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In my program, I have two types of structs, one with a very longvector, and another that holds a view of a sub-part of the vector of another, reshaped to a matrix. In principle this should work: function reshapeView(ve…

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## [Trapped in a int -\> missing -\> float loop](https://discourse.julialang.org/t/trapped-in-a-int-missing-float-loop/91578)

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**Author:** [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Replies:** 10\
**Last updated:** [December 13, 2022, 10:40am UTC](https://discourse.julialang.org/t/trapped-in-a-int-missing-float-loop/91578 "2022-12-13T10:40:33Z")

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Let’s say that I have a dataframe like df = DataFrame(a=\[ 1, 4, missing\], b= \[1, 4, 5\], c=\[1., 2, 3\]) 3×3 DataFrame Row │ a b c │ Int64? Int64 Float64 ─────┼───────────────────────── 1 │ 1…

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## [What's the difference between LinearAlgebra.axpy! and BLAS.axpy!, and which one should packages extend?](https://discourse.julialang.org/t/whats-the-difference-between-linearalgebra-axpy-and-blas-axpy-and-which-one-should-packages-extend/91585)

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**Author:** [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Replies:** 0\
**Last updated:** [December 13, 2022, 5:15am UTC](https://discourse.julialang.org/t/whats-the-difference-between-linearalgebra-axpy-and-blas-axpy-and-which-one-should-packages-extend/91585 "2022-12-13T05:15:08Z")

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BLAS sounds too low level, so intuitively I would think it’s LinearAlgebra.axpy! that packages should extend. However, what is the intended difference between the two? And when should one use one over the other? julia\> …

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## [Skip some tests on nightly in CI](https://discourse.julialang.org/t/skip-some-tests-on-nightly-in-ci/91425)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 2\
**Last updated:** [December 13, 2022, 9:27am UTC](https://discourse.julialang.org/t/skip-some-tests-on-nightly-in-ci/91425 "2022-12-13T09:27:08Z")

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I am using Github Actions for CI on a package. I want to skip some tests on nightly, but it is a moving target and I don’t want to keep updating the code after every release. I am wondering what the best way to do this …

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## [There is a huge difference in time consumption between calling a function sentence by sentence and calling the entire function at once](https://discourse.julialang.org/t/there-is-a-huge-difference-in-time-consumption-between-calling-a-function-sentence-by-sentence-and-calling-the-entire-function-at-once/82946)

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**Author:** [@HANHAOHAN](https://discourse.julialang.org/u/HANHAOHAN)\
**Replies:** 33\
**Last updated:** [December 13, 2022, 8:50am UTC](https://discourse.julialang.org/t/there-is-a-huge-difference-in-time-consumption-between-calling-a-function-sentence-by-sentence-and-calling-the-entire-function-at-once/82946 "2022-12-13T08:50:01Z")

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First, I statistics time consumer of each sentence with @btime: function (m::CoarseDecoder)(bg::T, fg, mask::T, encoder\_outs=nothing) where{T} bg\_x = bg mask\_x = mask mask\_outs = Vector{T}() bg\_outs = Ve…

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## [BSON error after project packages update \[Resolved\]](https://discourse.julialang.org/t/bson-error-after-project-packages-update-resolved/91547)

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**Author:** [@Maxim\_Lubov](https://discourse.julialang.org/u/Maxim_Lubov)\
**Replies:** 0\
**Last updated:** [December 12, 2022, 9:34am UTC](https://discourse.julialang.org/t/bson-error-after-project-packages-update-resolved/91547 "2022-12-12T09:34:05Z")

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I have update packages for my project and strange error occurs. I have also update Julia from 1.7.2 to 1.8.2. Previously following code works without problems: model2 = BSON.load(filepath, @\_\_MODULE\_\_) Now, I have fol…

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## [Confusing/misleading error message for a beginner](https://discourse.julialang.org/t/confusing-misleading-error-message-for-a-beginner/91277)

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**Author:** [@einar](https://discourse.julialang.org/u/einar)\
**Replies:** 10\
**Last updated:** [December 13, 2022, 3:42am UTC](https://discourse.julialang.org/t/confusing-misleading-error-message-for-a-beginner/91277 "2022-12-13T03:42:48Z")

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Note: This was originally meant to be a question, but I solved it along the way. However, I want to post it here anyway because it feels as a common beginner mistake and I wonder what could be done to improve the error m…

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## [Snail: how to copy from the vterm buffer](https://discourse.julialang.org/t/snail-how-to-copy-from-the-vterm-buffer/91573)

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**Author:** [@PeterSimon](https://discourse.julialang.org/u/PeterSimon)\
**Replies:** 2\
**Last updated:** [December 13, 2022, 3:27am UTC](https://discourse.julialang.org/t/snail-how-to-copy-from-the-vterm-buffer/91573 "2022-12-13T03:27:37Z")

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When using Snail in emacs, how does one copy a portion of the vterm (Julia session) buffer? All the normal emacs keys are disabled in the buffer running the Julia REPL, so I can’t figure out how to invoke, say, vterm-co…

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## [Example of the use DecisionTree.permutation\_importance function based on MLJ](https://discourse.julialang.org/t/example-of-the-use-decisiontree-permutation-importance-function-based-on-mlj/91521)

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**Author:** [@lgmendes](https://discourse.julialang.org/u/lgmendes)\
**Replies:** 2\
**Last updated:** [December 13, 2022, 1:57am UTC](https://discourse.julialang.org/t/example-of-the-use-decisiontree-permutation-importance-function-based-on-mlj/91521 "2022-12-13T01:57:23Z")

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Can someone give me a small example of how to use the function DecisionTree.permutation\_importance() using an MLJ Tree machine (Tree = @load DecisionTreeClassifier pkg=DecisionTree)? A Python similar function is sklear…

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## [Real fft of a 3D array with FFTW](https://discourse.julialang.org/t/real-fft-of-a-3d-array-with-fftw/91572)

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**Author:** [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)\
**Replies:** 2\
**Last updated:** [December 12, 2022, 10:52pm UTC](https://discourse.julialang.org/t/real-fft-of-a-3d-array-with-fftw/91572 "2022-12-12T22:52:38Z")

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Hi, I need to take the 3D fft of an array of real data. I’d like to do that using rfft() from the FFTW library rather than the usual fft() to speed up the process and keep memory requirements low. Now my data is stored…

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## [Does the function String() destroy its argument?](https://discourse.julialang.org/t/does-the-function-string-destroy-its-argument/91496)

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**Author:** [@mmv](https://discourse.julialang.org/u/mmv)\
**Replies:** 9\
**Last updated:** [December 12, 2022, 9:39pm UTC](https://discourse.julialang.org/t/does-the-function-string-destroy-its-argument/91496 "2022-12-12T21:39:10Z")

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Hi! I am using a C function from an existing shared library to convert a Julian day number into a date and time information in the ISO 8601 format (YYYY-MM-DDThh:mm:ssZ). This C function generates and returns a vector of…

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## [Confusion over string interpolation of a struct](https://discourse.julialang.org/t/confusion-over-string-interpolation-of-a-struct/91569)

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**Author:** [@healyp](https://discourse.julialang.org/u/healyp)\
**Replies:** 3\
**Last updated:** [December 12, 2022, 9:10pm UTC](https://discourse.julialang.org/t/confusion-over-string-interpolation-of-a-struct/91569 "2022-12-12T21:10:38Z")

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I would like to write a summary of a struct as a string. So I did the following: julia\> struct Cell{R\<:Int} row::R col::R end julia\> import Base.print julia\> print(io::IO, c::Cell) = pri…

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## [Inplace multiplication of sub-matrices without allocations](https://discourse.julialang.org/t/inplace-multiplication-of-sub-matrices-without-allocations/91534)

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**Author:** [@CeterisPartybus](https://discourse.julialang.org/u/CeterisPartybus)\
**Replies:** 12\
**Last updated:** [December 12, 2022, 8:44pm UTC](https://discourse.julialang.org/t/inplace-multiplication-of-sub-matrices-without-allocations/91534 "2022-12-12T20:44:36Z")

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I am writing a performance-critical part and would like to avoid any memory allocations in that part by creating caches beforehand. I then essentially need to multiply sub-arrays in a loop. Is there any way to do these m…

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## [How to properly use MLJBase.roc\_curve](https://discourse.julialang.org/t/how-to-properly-use-mljbase-roc-curve/90648)

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**Author:** [@adz](https://discourse.julialang.org/u/adz)\
**Replies:** 4\
**Last updated:** [December 12, 2022, 8:35pm UTC](https://discourse.julialang.org/t/how-to-properly-use-mljbase-roc-curve/90648 "2022-12-12T20:35:02Z")

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Hi all, I’m getting used to ML and Julia and am wondering how to properly make use of MLJ’s api. Specifically, I’m not sure what exactly it wants as arguments to MLJ.roc\_curve. Here is some code I use to train and evalua…

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## [Flux, categorical arrays, roc curves, confusion matrices](https://discourse.julialang.org/t/flux-categorical-arrays-roc-curves-confusion-matrices/91282)

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**Author:** [@Gravlax](https://discourse.julialang.org/u/Gravlax)\
**Replies:** 14\
**Last updated:** [December 12, 2022, 8:32pm UTC](https://discourse.julialang.org/t/flux-categorical-arrays-roc-curves-confusion-matrices/91282 "2022-12-12T20:32:29Z")

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Dear all, I’m trying Flux to build a prediction for the occurrence of an event given a data set containing both continuous (Float64) and categorical arrays (Int64). I’m learning from the tutorials and the talk Julia vid…

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## [Function that returns the UTM zone?](https://discourse.julialang.org/t/function-that-returns-the-utm-zone/91568)

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**Author:** [@alex-s-gardner](https://discourse.julialang.org/u/alex-s-gardner)\
**Replies:** 1\
**Last updated:** [December 12, 2022, 8:28pm UTC](https://discourse.julialang.org/t/function-that-returns-the-utm-zone/91568 "2022-12-12T20:28:27Z")

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Is there a Julia function that returns the UTM zone when given a latitude and longitude similar to Matlab’s utmzone?

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## [Why is a multi-argument inplace map much faster in this case than a broadcast?](https://discourse.julialang.org/t/why-is-a-multi-argument-inplace-map-much-faster-in-this-case-than-a-broadcast/91525)

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**Author:** [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Replies:** 16\
**Last updated:** [December 12, 2022, 7:14pm UTC](https://discourse.julialang.org/t/why-is-a-multi-argument-inplace-map-much-faster-in-this-case-than-a-broadcast/91525 "2022-12-12T19:14:55Z")

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julia\> A = rand(10, 1000); B = copy(A); C = zero(A); D = zero(A); julia\> @btime map!(+, $C, $A, $B); 3.405 μs (0 allocations: 0 bytes) julia\> @btime $D .= $A .+ $B; 10.915 μs (0 allocations: 0 bytes) julia\> A = r…

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## [Loop unrolling for type stability](https://discourse.julialang.org/t/loop-unrolling-for-type-stability/91565)

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**Author:** [@smartalecH](https://discourse.julialang.org/u/smartalecH)\
**Replies:** 6\
**Last updated:** [December 12, 2022, 6:27pm UTC](https://discourse.julialang.org/t/loop-unrolling-for-type-stability/91565 "2022-12-12T18:27:53Z")

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I (naively) thought that the compiler would do some basic loop unrolling. This is particularly important for generating type-stable code. Is there a way I can easily make the following code snippet stable? abstract type…

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## [How to add data labels to bar plot?](https://discourse.julialang.org/t/how-to-add-data-labels-to-bar-plot/56168)

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**Author:** [@Ivan](https://discourse.julialang.org/u/Ivan)\
**Replies:** 6\
**Last updated:** [December 12, 2022, 6:05pm UTC](https://discourse.julialang.org/t/how-to-add-data-labels-to-bar-plot/56168 "2022-12-12T18:05:56Z")

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I want to add data labels to the bars of my bar plot, as seen here: (chart and python code accessible here How do I do it? Right now what I have is: plotly() y = rand(5) x = string.(\[1,2,3,4,5\]) using Plots bar = pl…

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## [Strange behavior with DifferentialEquations.jl](https://discourse.julialang.org/t/strange-behavior-with-differentialequations-jl/91562)

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**Author:** [@erlebach](https://discourse.julialang.org/u/erlebach)\
**Replies:** 3\
**Last updated:** [December 12, 2022, 5:31pm UTC](https://discourse.julialang.org/t/strange-behavior-with-differentialequations-jl/91562 "2022-12-12T17:31:04Z")

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@ChrisRackauckas, I know you are busy today, but for afterwards, I have what “seems” to be a bug in DifferentialEquations.jl. Here is a MWE: using DifferentialEquations ## Data generation function lotka!(du, u, p, t) …

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## [Accessing only a subset of function outputs](https://discourse.julialang.org/t/accessing-only-a-subset-of-function-outputs/91558)

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**Author:** [@Atiyah](https://discourse.julialang.org/u/Atiyah)\
**Replies:** 7\
**Last updated:** [December 12, 2022, 4:49pm UTC](https://discourse.julialang.org/t/accessing-only-a-subset-of-function-outputs/91558 "2022-12-12T16:49:10Z")

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suppose that there is a function with several return values function foo() ... ret1, ret2, ret3 end and suppose that a caller is interested in a particular subset of the return values and not all of them. How cou…

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