# General Usage

**URL:** https://discourse.julialang.org/c/usage/6.md?page=485

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**Page:** 486

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## [Is 1.7.2 on Intel Mac missing Codesigning?](https://discourse.julialang.org/t/is-1-7-2-on-intel-mac-missing-codesigning/76099)

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**Author:** [@ctkelley](https://discourse.julialang.org/u/ctkelley)\
**Replies:** 3\
**Last updated:** [February 9, 2022, 4:08pm UTC](https://discourse.julialang.org/t/is-1-7-2-on-intel-mac-missing-codesigning/76099 "2022-02-09T16:08:17Z")

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Intel Mac, latest OS, got this in a popup “julia” can’t be opened because the identity of the developer cannot be confirmed. M1 version on Macbook works fine.

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## [Time series datatypes](https://discourse.julialang.org/t/time-series-datatypes/76092)

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**Author:** [@Mastomaki](https://discourse.julialang.org/u/Mastomaki)\
**Replies:** 0\
**Last updated:** [February 9, 2022, 3:19pm UTC](https://discourse.julialang.org/t/time-series-datatypes/76092 "2022-02-09T15:19:59Z")

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Hello! What datatype do you recommed for time series? I would need things like in Pandas: access like Pandas “loc” aggregation conversion between time zones interpolation time shifts & differences moving averages inne…

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## [Using Winston corrupts BigInts?](https://discourse.julialang.org/t/using-winston-corrupts-bigints/76077)

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**Author:** [@harven](https://discourse.julialang.org/u/harven)\
**Replies:** 3\
**Last updated:** [February 9, 2022, 2:58pm UTC](https://discourse.julialang.org/t/using-winston-corrupts-bigints/76077 "2022-02-09T14:58:32Z")

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The following weird behavior appears with julia 1.7.1 and Winston v0.15.2 julia\> big(1//2) 1//2 julia\> using Winston Gtk-Message: 14:17:40.676: Failed to load module "canberra-gtk-module" Gtk-Message: 14:17:40.677: Fai…

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## [Create new column with first row of each id](https://discourse.julialang.org/t/create-new-column-with-first-row-of-each-id/76083)

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**Author:** [@sai\_matcha](https://discourse.julialang.org/u/sai_matcha)\
**Replies:** 1\
**Last updated:** [February 9, 2022, 2:28pm UTC](https://discourse.julialang.org/t/create-new-column-with-first-row-of-each-id/76083 "2022-02-09T14:28:05Z")

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Hi , i want to create a new column with the first row of each id . this is the data i have df = DataFrame() df.id = repeat(1:3,3) df.x1 = 1:9 df.x2 = 10:18 sort!(df,:id) i want column x3 as first row of each id in col…

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## [Implementation of Spectral Normalization for Machine Learning](https://discourse.julialang.org/t/implementation-of-spectral-normalization-for-machine-learning/76074)

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**Author:** [@Hareruya](https://discourse.julialang.org/u/Hareruya)\
**Replies:** 7\
**Last updated:** [February 9, 2022, 2:15pm UTC](https://discourse.julialang.org/t/implementation-of-spectral-normalization-for-machine-learning/76074 "2022-02-09T14:15:44Z")

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Greetings. I have migrated most of my Machine Learning work from working in Pytorch for Flux and have not felt the need to look back(especially as I move towards SciML), however there was a small hiccup I’d like t inqui…

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## [Parallel Reductions with Zygote](https://discourse.julialang.org/t/parallel-reductions-with-zygote/75969)

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**Author:** [@SEA](https://discourse.julialang.org/u/SEA)\
**Replies:** 11\
**Last updated:** [February 9, 2022, 1:05pm UTC](https://discourse.julialang.org/t/parallel-reductions-with-zygote/75969 "2022-02-09T13:05:38Z")

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I am trying to speed up the gradient computation of a model of the form sum(m-\>m(x), models), where models is an array of constituent models. This is (supposed to be) easily parallelizable, but I am having trouble maki…

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## [Unexpected allocations in loops](https://discourse.julialang.org/t/unexpected-allocations-in-loops/74063)

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**Author:** [@t-bltg](https://discourse.julialang.org/u/t-bltg)\
**Replies:** 8\
**Last updated:** [February 9, 2022, 12:49pm UTC](https://discourse.julialang.org/t/unexpected-allocations-in-loops/74063 "2022-02-09T12:49:12Z")

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Consider the following reduced example: using BenchmarkTools const F = Float64 struct Species q::F ρ::Array{F} end addCharge!(dst::Array{F}, q::F, ρ::Array{F}) = for I ∈ eachindex(dst) dst\[I\] += q \* ρ\[I\] end a…

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## [Get any object properties by name](https://discourse.julialang.org/t/get-any-object-properties-by-name/76070)

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**Author:** [@andrey2185](https://discourse.julialang.org/u/andrey2185)\
**Replies:** 6\
**Last updated:** [February 9, 2022, 12:45pm UTC](https://discourse.julialang.org/t/get-any-object-properties-by-name/76070 "2022-02-09T12:45:00Z")

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Hello, I need to get object property values by their names. The order of the values must match the order of the property names. Can it be done better? struct TestObject a b c end object = TestObject(1,2,3…

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## [How to find details of the compiler and optimizations used by a specific installed version of Julia](https://discourse.julialang.org/t/how-to-find-details-of-the-compiler-and-optimizations-used-by-a-specific-installed-version-of-julia/75501)

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**Author:** [@DavidB](https://discourse.julialang.org/u/DavidB)\
**Replies:** 11\
**Last updated:** [February 9, 2022, 11:23am UTC](https://discourse.julialang.org/t/how-to-find-details-of-the-compiler-and-optimizations-used-by-a-specific-installed-version-of-julia/75501 "2022-02-09T11:23:28Z")

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I’ve noticed that there is a performance significant difference in the execution of a Julia application between “bare metal” and within a container, but only on one specific platform. So want to see if there was a differ…

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## ["Cat" very slow for relativelly small tasks](https://discourse.julialang.org/t/cat-very-slow-for-relativelly-small-tasks/76067)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 2\
**Last updated:** [February 9, 2022, 10:55am UTC](https://discourse.julialang.org/t/cat-very-slow-for-relativelly-small-tasks/76067 "2022-02-09T10:55:23Z")

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This make my 16GB system hang for a while and eventually crash with a StackOverflowError, even if top doesn’t show all this memory usage (the matrices themselves should be ~ 400 MB) mainM = rand(28,28,60000) toAdd = \[ra…

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## [Could not download registries Julia 1.7.2](https://discourse.julialang.org/t/could-not-download-registries-julia-1-7-2/76062)

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**Author:** [@HerAdri](https://discourse.julialang.org/u/HerAdri)\
**Replies:** 0\
**Last updated:** [February 9, 2022, 7:27am UTC](https://discourse.julialang.org/t/could-not-download-registries-julia-1-7-2/76062 "2022-02-09T07:27:22Z")

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(@v1.7) pkg\> st Installing known registries into \`C:\\Users\\Hermesr\\.julia\` ┌ Warning: could not download https://pkg.julialang.org/registries │ exception = schannel: failed to receive handshake, SSL/TLS connection fa…

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## [\[ANN\] Announcing Denumpyfy.jl](https://discourse.julialang.org/t/ann-announcing-denumpyfy-jl/76058)

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**Author:** [@miguelraz](https://discourse.julialang.org/u/miguelraz)\
**Replies:** 0\
**Last updated:** [February 9, 2022, 2:21am UTC](https://discourse.julialang.org/t/ann-announcing-denumpyfy-jl/76058 "2022-02-09T02:21:49Z")

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Hey gang! I’ve rewritten way too many numpy notebooks, so I figured I might as well throw these 20 regexes into a package to free myself and others from this burden. Here’s Denumpyfy.jl https://github.com/miguelraz/De…

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## [Question on Metaprogramming Example from Docs](https://discourse.julialang.org/t/question-on-metaprogramming-example-from-docs/75992)

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**Author:** [@TI36XPro](https://discourse.julialang.org/u/TI36XPro)\
**Replies:** 3\
**Last updated:** [February 9, 2022, 1:24am UTC](https://discourse.julialang.org/t/question-on-metaprogramming-example-from-docs/75992 "2022-02-09T01:24:10Z")

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Hello, I have been reviewing the metaprogamming section of the docs and I have come across something I don’t understand. I am looking at the second example in the subsection on interpolation, here. The example is showin…

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## [Antisymmetric matrices?](https://discourse.julialang.org/t/antisymmetric-matrices/75829)

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**Author:** [@akriegman](https://discourse.julialang.org/u/akriegman)\
**Replies:** 4\
**Last updated:** [February 5, 2022, 10:14pm UTC](https://discourse.julialang.org/t/antisymmetric-matrices/75829 "2022-02-05T22:14:57Z")

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The LinearAlgebra module in the standard library has several special matrix types which represent various sparse matrix types, like symmetric or upper-triangular. This allows for reduced memory usage as you can avoid sto…

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## [Gradient of a gradient of a FastChain](https://discourse.julialang.org/t/gradient-of-a-gradient-of-a-fastchain/73876)

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**Author:** [@mahdiar](https://discourse.julialang.org/u/mahdiar)\
**Replies:** 19\
**Last updated:** [February 8, 2022, 3:58pm UTC](https://discourse.julialang.org/t/gradient-of-a-gradient-of-a-fastchain/73876 "2022-02-08T15:58:28Z")

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What is the best way to differentiate an artificial neural network built by FastChain? The objective is to make a gradient of a neural network output with respect to its output. The result should be differentiable. Her…

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## [A question about Clustering.jl](https://discourse.julialang.org/t/a-question-about-clustering-jl/76030)

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**Author:** [@abcde](https://discourse.julialang.org/u/abcde)\
**Replies:** 1\
**Last updated:** [February 8, 2022, 3:36pm UTC](https://discourse.julialang.org/t/a-question-about-clustering-jl/76030 "2022-02-08T15:36:25Z")

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This is my code: using Clustering #dist = Distances.Euclidean() X1 = rand(10, 10) #dm = Distances.pairwise(dist, X1, dims=2) ppresult=kmeans(X1,2) But it has the following errors: ERROR: LoadError: UndefVarError: …

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## [Mouse-over popout from inline result in VSCode is tiny](https://discourse.julialang.org/t/mouse-over-popout-from-inline-result-in-vscode-is-tiny/76028)

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**Author:** [@TheLateKronos](https://discourse.julialang.org/u/TheLateKronos)\
**Replies:** 2\
**Last updated:** [February 8, 2022, 3:03pm UTC](https://discourse.julialang.org/t/mouse-over-popout-from-inline-result-in-vscode-is-tiny/76028 "2022-02-08T15:03:06Z")

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I installed VSCode on another machine (Linux). I logged in, and synchronized stuff (settings etc.) from my profile. On this new machine, the pop-out when mousing over inline results was tiny. When I got back to my main …

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## [Improving performance of recursions by avoiding closures](https://discourse.julialang.org/t/improving-performance-of-recursions-by-avoiding-closures/76026)

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**Author:** [@lucifer1004](https://discourse.julialang.org/u/lucifer1004)\
**Replies:** 0\
**Last updated:** [February 8, 2022, 2:15pm UTC](https://discourse.julialang.org/t/improving-performance-of-recursions-by-avoiding-closures/76026 "2022-02-08T14:15:06Z")

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Just implemented Tarjan’s SCC (strongly-connected components) algorithm. In the first version, I created the dfs() function (which is recursive) inside the scc() function, and let it capture the needed variables from the…

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## [@printf strange performance behavior](https://discourse.julialang.org/t/printf-strange-performance-behavior/76013)

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**Author:** [@\_bernhard](https://discourse.julialang.org/u/_bernhard)\
**Replies:** 1\
**Last updated:** [February 8, 2022, 1:52pm UTC](https://discourse.julialang.org/t/printf-strange-performance-behavior/76013 "2022-02-08T13:52:16Z")

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Hello everybody! I recently encountered some strange behavior related to printing numbers as ASCII in Julia. Tested were both Julia 1.6 and 1.7, the following timings are from 1.6. using Printf using BenchmarkTools f…

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## [Scraping youtube webcomments with WebDriver.jl](https://discourse.julialang.org/t/scraping-youtube-webcomments-with-webdriver-jl/75996)

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**Author:** [@Tomas\_Pevny](https://discourse.julialang.org/u/Tomas_Pevny)\
**Replies:** 2\
**Last updated:** [February 8, 2022, 1:25pm UTC](https://discourse.julialang.org/t/scraping-youtube-webcomments-with-webdriver-jl/75996 "2022-02-08T13:25:02Z")

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Hi All, I am trying to replicate this post How to Scrape Youtube Comments with Python | by François St-Amant | Towards Data Science in Julia. The author scrapes comments from yt videos using selenium driver and does som…

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## [Partial initialisation of a (Named)Tuple?](https://discourse.julialang.org/t/partial-initialisation-of-a-named-tuple/76011)

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**Author:** [@willtebbutt](https://discourse.julialang.org/u/willtebbutt)\
**Replies:** 8\
**Last updated:** [February 8, 2022, 1:21pm UTC](https://discourse.julialang.org/t/partial-initialisation-of-a-named-tuple/76011 "2022-02-08T13:21:52Z")

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I’m trying to figure out whether it’s possible to partially initialise a Tuple / NamedTuple. A concrete example: I would like to be able to write something like x = Tuple{Vector{Float64}, Vector{Float64}}(randn(5)) isd…

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## [What's the optimal setting for JULIA\_NUM\_THREADS on a Macbook Pro M1 Max](https://discourse.julialang.org/t/whats-the-optimal-setting-for-julia-num-threads-on-a-macbook-pro-m1-max/75928)

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**Author:** [@navidcy](https://discourse.julialang.org/u/navidcy)\
**Replies:** 4\
**Last updated:** [February 8, 2022, 12:55pm UTC](https://discourse.julialang.org/t/whats-the-optimal-setting-for-julia-num-threads-on-a-macbook-pro-m1-max/75928 "2022-02-08T12:55:19Z")

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with Total Numbers of Cores: 10 (8 performance and 2 efficiency)? Is it 10? 8? 20? 16?

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## [Construct NamedTuple dynamically](https://discourse.julialang.org/t/construct-namedtuple-dynamically/15394)

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**Author:** [@tk3369](https://discourse.julialang.org/u/tk3369)\
**Replies:** 12\
**Last updated:** [February 8, 2022, 9:11am UTC](https://discourse.julialang.org/t/construct-namedtuple-dynamically/15394 "2022-02-08T09:11:06Z")

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In Julia 1.0, I can constructed a named tuple with known names and values. x = (a = 1, b = 2.0, c = "hello world") Let’s say I have the names and values in separate arrays. How could I construct a named tuple dynamica…

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## [Function to calculate temperature from steamtable look up in Julia](https://discourse.julialang.org/t/function-to-calculate-temperature-from-steamtable-look-up-in-julia/75974)

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**Author:** [@Curio\_math](https://discourse.julialang.org/u/Curio_math)\
**Replies:** 5\
**Last updated:** [February 8, 2022, 5:50am UTC](https://discourse.julialang.org/t/function-to-calculate-temperature-from-steamtable-look-up-in-julia/75974 "2022-02-08T05:50:30Z")

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I have been using a dynamic mathematical model, where I assume to replace some nonlinear functions corresponding to finding temperature (as a function of pressure and enthalpy) by substituting them with functions inbuild…

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## [Counting iterations to a type fixpoint](https://discourse.julialang.org/t/counting-iterations-to-a-type-fixpoint/75876)

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**Author:** [@cscherrer](https://discourse.julialang.org/u/cscherrer)\
**Replies:** 11\
**Last updated:** [February 8, 2022, 3:35am UTC](https://discourse.julialang.org/t/counting-iterations-to-a-type-fixpoint/75876 "2022-02-08T03:35:25Z")

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I have a function that typically gives a value of a different type, but repeated application eventually hits a fixpoint. Say the function is called next. I need the fixpoint in order to statically build a loop like @gen…

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## [Using Debugger in Julia 1.6.3](https://discourse.julialang.org/t/using-debugger-in-julia-1-6-3/71095)

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**Author:** [@kw\_martin](https://discourse.julialang.org/u/kw_martin)\
**Replies:** 17\
**Last updated:** [February 8, 2022, 1:30am UTC](https://discourse.julialang.org/t/using-debugger-in-julia-1-6-3/71095 "2022-02-08T01:30:45Z")

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I am having difficulties using Debugger in Julia 1.6.3. I attempted to run the simple example from Debugger at github and if failed. Can someone suggest what I am doing wrong or a work-around. I do have vscode working, b…

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## [Can a method push! to a Vector that is a field in a struct?](https://discourse.julialang.org/t/can-a-method-push-to-a-vector-that-is-a-field-in-a-struct/75964)

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**Author:** [@dmbates](https://discourse.julialang.org/u/dmbates)\
**Replies:** 5\
**Last updated:** [February 7, 2022, 8:39pm UTC](https://discourse.julialang.org/t/can-a-method-push-to-a-vector-that-is-a-field-in-a-struct/75964 "2022-02-07T20:39:38Z")

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In https://github.com/dmbates/Wordlegames.jl I use a struct to represent the state of a Wordle (or similar) game. I am thinking of recording the history of guesses and scores from these guess as fields which will be Vec…

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## [Finding DataFrame rows with \`missing\` values in specific columns?](https://discourse.julialang.org/t/finding-dataframe-rows-with-missing-values-in-specific-columns/75811)

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**Author:** [@forestacorn](https://discourse.julialang.org/u/forestacorn)\
**Replies:** 12\
**Last updated:** [February 7, 2022, 6:01pm UTC](https://discourse.julialang.org/t/finding-dataframe-rows-with-missing-values-in-specific-columns/75811 "2022-02-07T18:01:56Z")

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I have a DataFrame, like the following example, where I am trying to find the rows where the columns x2 and x3 are missing values: df = DataFrame(\[1 2 3; 4 5 6; 7 missing missing; 10 11 12; 13 missing missing; 16 17 18\]…

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## [Broken \`eigen\` in DoubleFloats?](https://discourse.julialang.org/t/broken-eigen-in-doublefloats/75946)

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**Author:** [@swishmas](https://discourse.julialang.org/u/swishmas)\
**Replies:** 1\
**Last updated:** [February 7, 2022, 2:41pm UTC](https://discourse.julialang.org/t/broken-eigen-in-doublefloats/75946 "2022-02-07T14:41:19Z")

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I wanted to try some additional precision in julia and I found the DoubleFloats package. I ran the small example but received an error when using the eigen function #using LinearAlgebra #did not change the result using…

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## [How to keep the value of function pointer?](https://discourse.julialang.org/t/how-to-keep-the-value-of-function-pointer/75576)

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**Author:** [@Laco\_Kovac](https://discourse.julialang.org/u/Laco_Kovac)\
**Replies:** 5\
**Last updated:** [February 7, 2022, 1:48pm UTC](https://discourse.julialang.org/t/how-to-keep-the-value-of-function-pointer/75576 "2022-02-07T13:48:27Z")

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How to keep the value of function pointer? This is roughly how the code looks like: gCallBackFunc = Ref{Function}(func1) ... callBack::Function = gCallBackFunc\[\] ... gCallBackFunc\[\] = func2 ... callBack(params) I want…

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