# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1324

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

**Page:** 1325

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## [Skipping a whole \`@testset\`?](https://discourse.julialang.org/t/skipping-a-whole-testset/65006)

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**Author:** [@johnomotani](https://discourse.julialang.org/u/johnomotani)\
**Replies:** 3\
**Last updated:** [July 21, 2021, 7:21pm UTC](https://discourse.julialang.org/t/skipping-a-whole-testset/65006 "2021-07-21T19:21:26Z")

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I have a bunch of similar @testsets, and I know that some of them currently fail, and will do so until some upgrades are made to my package. For skipping single tests, there’s @test\_skip or @test\_broken, but is there a n…

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## [Corrections to other posts: best practices?](https://discourse.julialang.org/t/corrections-to-other-posts-best-practices/65044)

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**Author:** [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Replies:** 6\
**Last updated:** [July 21, 2021, 6:57pm UTC](https://discourse.julialang.org/t/corrections-to-other-posts-best-practices/65044 "2021-07-21T18:57:28Z")

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@pakk-minidose, I do not understand much of the code but it is apparent that @stevengj did all the hard work, you added one line close(fle) to it, and you attributed to yourself the solution of your own question? Sorry i…

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## [Using IJulia throws error](https://discourse.julialang.org/t/using-ijulia-throws-error/65035)

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**Author:** [@valli](https://discourse.julialang.org/u/valli)\
**Replies:** 4\
**Last updated:** [July 21, 2021, 6:08pm UTC](https://discourse.julialang.org/t/using-ijulia-throws-error/65035 "2021-07-21T18:08:11Z")

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Hi, I am new to the julia paradigm and have been trying to run the tutorials in the JuliaCon2021. I use their project.toml and instantiate my project. I get some errors with most .jll files which I am not sure how to fi…

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## [Organizing a project with a CLI](https://discourse.julialang.org/t/organizing-a-project-with-a-cli/65005)

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**Author:** [@orome](https://discourse.julialang.org/u/orome)\
**Replies:** 2\
**Last updated:** [July 21, 2021, 5:09pm UTC](https://discourse.julialang.org/t/organizing-a-project-with-a-cli/65005 "2021-07-21T17:09:07Z")

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I have a project that I’d like to add a CLI to (using Comonicon.jl) and I’m not sure how to organize the addition of the CLI. Ideally I’d like to keep by base project, MyPackage on its own so people can just add/using M…

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## [How to compute the rolling standardization using DataFrames](https://discourse.julialang.org/t/how-to-compute-the-rolling-standardization-using-dataframes/64976)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 8\
**Last updated:** [July 21, 2021, 3:54pm UTC](https://discourse.julialang.org/t/how-to-compute-the-rolling-standardization-using-dataframes/64976 "2021-07-21T15:54:42Z")

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using DataFrames data = DataFrame(time = rand(1:100, 1\_000\_000), val=rand(1\_000\_000)) consider the above data frame and say I wish to compute the average val within a rolling window and normalize each val using the roll…

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## [Function input vs argument](https://discourse.julialang.org/t/function-input-vs-argument/65040)

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**Author:** [@AhmedAlreweny](https://discourse.julialang.org/u/AhmedAlreweny)\
**Replies:** 1\
**Last updated:** [July 21, 2021, 3:48pm UTC](https://discourse.julialang.org/t/function-input-vs-argument/65040 "2021-07-21T15:48:03Z")

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Hi, Sometimes it happens that I want to define a function f(x,y) that have two arguments (x ,y in this case ) to use it further in gradient computation or some similar application that requires a clear explicit definit…

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## [MethodError: Evolution of Out Of Sample Performance Range](https://discourse.julialang.org/t/methoderror-evolution-of-out-of-sample-performance-range/65041)

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**Author:** [@YummyPampers2](https://discourse.julialang.org/u/YummyPampers2)\
**Replies:** 1\
**Last updated:** [July 21, 2021, 3:46pm UTC](https://discourse.julialang.org/t/methoderror-evolution-of-out-of-sample-performance-range/65041 "2021-07-21T15:46:33Z")

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Hello Folks: I am using MLJ@.load\_boston data where feat, targ = MLJ.@load\_boston feat = DataFrames.DataFrame(feat) targ = categorical(targ) I have split the categorical.array using: rng = 52 TRAIN, TEST = partit…

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## [Get DCT coefficients of jpeg image](https://discourse.julialang.org/t/get-dct-coefficients-of-jpeg-image/64640)

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**Author:** [@pakk-minidose](https://discourse.julialang.org/u/pakk-minidose)\
**Replies:** 11\
**Last updated:** [July 21, 2021, 2:05pm UTC](https://discourse.julialang.org/t/get-dct-coefficients-of-jpeg-image/64640 "2021-07-21T14:05:59Z")

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Hello, I would like to obtain DCT coefficients of a jpeg image. The Phil Sallee’s JPEG toolbox in MATLAB returns these as an array (the original website is not active, but some of the code can be downloaded on Jessica …

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## [ODE with vector Argument](https://discourse.julialang.org/t/ode-with-vector-argument/64918)

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**Author:** [@aiiiob\_bie](https://discourse.julialang.org/u/aiiiob_bie)\
**Replies:** 17\
**Last updated:** [July 21, 2021, 3:53am UTC](https://discourse.julialang.org/t/ode-with-vector-argument/64918 "2021-07-21T03:53:50Z")

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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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## [Problem combining worker processes and threads](https://discourse.julialang.org/t/problem-combining-worker-processes-and-threads/64069)

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**Author:** [@orenbenkiki](https://discourse.julialang.org/u/orenbenkiki)\
**Replies:** 8\
**Last updated:** [July 21, 2021, 2:04pm UTC](https://discourse.julialang.org/t/problem-combining-worker-processes-and-threads/64069 "2021-07-21T14:04:55Z")

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(Running julia 1.6.1 if that matters) Seeking help in understanding what am I doing wrong in an application which combines multiple worker processes and multiple threads within each one. I’ve been pushing and pulling at…

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## [Multi-threadded processing of large number of files faster when reading in batch](https://discourse.julialang.org/t/multi-threadded-processing-of-large-number-of-files-faster-when-reading-in-batch/64968)

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**Author:** [@Tomas\_Pevny](https://discourse.julialang.org/u/Tomas_Pevny)\
**Replies:** 10\
**Last updated:** [July 21, 2021, 1:27pm UTC](https://discourse.julialang.org/t/multi-threadded-processing-of-large-number-of-files-faster-when-reading-in-batch/64968 "2021-07-21T13:27:17Z")

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Dear All, I would like to ask a question about a behavior of multi-threadding. My usecase is following. I have on disk 800 000 files containing compressed JSONs, and I want to find those containing some predefined set o…

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## [Getting NaN output from JuMP variable after solving](https://discourse.julialang.org/t/getting-nan-output-from-jump-variable-after-solving/65026)

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**Author:** [@manoj.centura](https://discourse.julialang.org/u/manoj.centura)\
**Replies:** 4\
**Last updated:** [July 21, 2021, 1:22pm UTC](https://discourse.julialang.org/t/getting-nan-output-from-jump-variable-after-solving/65026 "2021-07-21T13:22:20Z")

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Hi All, I am running a linear program with Gurobi. The variable is set as @variable(mod2,0\<=L\_time\_bC\[b in 1:18, c in 1:3\] ) \`\`\` I am using julia 1.62 with \[c52e3926\] Atom v0.12.32 \[336ed68f\] CSV v0.8.5 \[9961bab8\] …

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## [Problem with @async and remotecall\_fetch()](https://discourse.julialang.org/t/problem-with-async-and-remotecall-fetch/65022)

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**Author:** [@WeiMXi](https://discourse.julialang.org/u/WeiMXi)\
**Replies:** 1\
**Last updated:** [July 21, 2021, 11:46am UTC](https://discourse.julialang.org/t/problem-with-async-and-remotecall-fetch/65022 "2021-07-21T11:46:57Z")

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I have the following code, my purpose is assigning the tasks to the different workers, and print the progress. # bug.jl # a simple calculation task function cal\_one\_task(size) a = rand(size) sum(a) end # manag…

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## [VSCode: Unicode tab completion stopped working](https://discourse.julialang.org/t/vscode-unicode-tab-completion-stopped-working/65001)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 6\
**Last updated:** [July 21, 2021, 11:14am UTC](https://discourse.julialang.org/t/vscode-unicode-tab-completion-stopped-working/65001 "2021-07-21T11:14:34Z")

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Some days ago the tab completion (of Unicode chars) suddenly stopped working on VSCode. I only have these plugins installed: I have only recently started using VSCode. I don’t see any error message anywhere. Any idea…

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## [Accessing array element: splatting VS explicit writing them out](https://discourse.julialang.org/t/accessing-array-element-splatting-vs-explicit-writing-them-out/64973)

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**Author:** [@pmlo](https://discourse.julialang.org/u/pmlo)\
**Replies:** 4\
**Last updated:** [July 21, 2021, 11:39am UTC](https://discourse.julialang.org/t/accessing-array-element-splatting-vs-explicit-writing-them-out/64973 "2021-07-21T11:39:59Z")

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Dear Julia experts. Another newbie question. I try the following (equivalent?) ways to assessing (& operating on) array elements latt\[x..., d\] VS latt\[x\[1\], x\[2\], x\[3\], d\] and find big difference in performance. I wou…

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## [Running myBinder with julia version 1.6](https://discourse.julialang.org/t/running-mybinder-with-julia-version-1-6/64920)

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**Author:** [@bennibolm](https://discourse.julialang.org/u/bennibolm)\
**Replies:** 7\
**Last updated:** [July 21, 2021, 11:35am UTC](https://discourse.julialang.org/t/running-mybinder-with-julia-version-1-6/64920 "2021-07-21T11:35:58Z")

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Hi, I hope this is the right place to ask. Every time I want to start my .ipynb file with mybinder there is no kernel for julia version 1.6.2 or 1.6.1. I can’t find any instructions on the binder website regarding the s…

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## [Problem with launching Jupyter notebook in Windows](https://discourse.julialang.org/t/problem-with-launching-jupyter-notebook-in-windows/59969)

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**Author:** [@Sarthak\_Choudhury](https://discourse.julialang.org/u/Sarthak_Choudhury)\
**Replies:** 5\
**Last updated:** [July 21, 2021, 10:58am UTC](https://discourse.julialang.org/t/problem-with-launching-jupyter-notebook-in-windows/59969 "2021-07-21T10:58:46Z")

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Hi, I wanted to launch a jupyter notebook using IJulia. After adding IJulia as a package, I tried notebook(). It asks permission to install Jupyter via Conda. It throws the following error about permission being denied…

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## [For loop inside an if condition statement](https://discourse.julialang.org/t/for-loop-inside-an-if-condition-statement/65027)

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**Author:** [@user\_231578](https://discourse.julialang.org/u/user_231578)\
**Replies:** 4\
**Last updated:** [July 21, 2021, 9:37am UTC](https://discourse.julialang.org/t/for-loop-inside-an-if-condition-statement/65027 "2021-07-21T09:37:50Z")

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Is it possible to add a loop inside an if condition? I would like to achieve this n = 3; A = rand(0:10, n); B = rand(0:10, 10, n); C = rand(0:10, n); flag = 0; for i in 1:n if A\[i\] == B\[C\[i\], i\] flag = 1; e…

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## [Trouble installing VS Code for Julia](https://discourse.julialang.org/t/trouble-installing-vs-code-for-julia/64897)

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**Author:** [@cybervigilante](https://discourse.julialang.org/u/cybervigilante)\
**Replies:** 5\
**Last updated:** [July 21, 2021, 8:38am UTC](https://discourse.julialang.org/t/trouble-installing-vs-code-for-julia/64897 "2021-07-21T08:38:49Z")

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Well, I tried installing Visual Studio for Julia. I Should have known Visual Studio would be a pain in the ass. I got the Julia extension. Then it wanted me to create a launch.json file (no idea how to do that). Then it …

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## [If tuplex can do it. So can Julia!](https://discourse.julialang.org/t/if-tuplex-can-do-it-so-can-julia/64979)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 4\
**Last updated:** [July 21, 2021, 8:22am UTC](https://discourse.julialang.org/t/if-tuplex-can-do-it-so-can-julia/64979 "2021-07-21T08:22:45Z")

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I got curious about Tuplex as it talked about at work and I started to read some of its papers and I found Today’s data science pipelines often rely on user-defined functions (UDFs) written in Python. But interpreted P…

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## [Generic square matrix constructor from a vector?](https://discourse.julialang.org/t/generic-square-matrix-constructor-from-a-vector/62306)

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**Author:** [@Vasily\_Pisarev](https://discourse.julialang.org/u/Vasily_Pisarev)\
**Replies:** 1\
**Last updated:** [July 21, 2021, 5:42am UTC](https://discourse.julialang.org/t/generic-square-matrix-constructor-from-a-vector/62306 "2021-07-21T05:42:24Z")

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Is there a generic way, given a vector, to produce a square matrix of the “best matching” type? By “best matching” I mean here Matrix for Base vectors and views, MMatrix for static arrays and SizedMatrix for SizedVectors…

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## [Passing data to modeling toolkit from a frontend](https://discourse.julialang.org/t/passing-data-to-modeling-toolkit-from-a-frontend/65013)

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**Author:** [@juliascrub](https://discourse.julialang.org/u/juliascrub)\
**Replies:** 0\
**Last updated:** [July 21, 2021, 4:14am UTC](https://discourse.julialang.org/t/passing-data-to-modeling-toolkit-from-a-frontend/65013 "2021-07-21T04:14:25Z")

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I am working on a little frontend for my modeling toolkit based project. let’s say I have a model my\_model. It has 3 parameters a,b, and c. I can call string.(parameters(my\_model)) and get a list of the parameter names,…

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## [@expression v.s. @constraint (when to use what)](https://discourse.julialang.org/t/expression-v-s-constraint-when-to-use-what/65008)

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**Author:** [@SingingKim](https://discourse.julialang.org/u/SingingKim)\
**Replies:** 5\
**Last updated:** [July 21, 2021, 3:11am UTC](https://discourse.julialang.org/t/expression-v-s-constraint-when-to-use-what/65008 "2021-07-21T03:11:57Z")

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I’m pretty sure this question will be redundant, but I could not find an answer anywhere. My question is more like asking a style guide so that my code can avoid any unnecessary build/calculation time. Q1. My guess is b…

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## [ModelingToolkit: how to get variable index of ODE solution as interpolating function](https://discourse.julialang.org/t/modelingtoolkit-how-to-get-variable-index-of-ode-solution-as-interpolating-function/64999)

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**Author:** [@Egwene\_al\_Vere](https://discourse.julialang.org/u/Egwene_al_Vere)\
**Replies:** 2\
**Last updated:** [July 21, 2021, 1:16am UTC](https://discourse.julialang.org/t/modelingtoolkit-how-to-get-variable-index-of-ode-solution-as-interpolating-function/64999 "2021-07-21T01:16:39Z")

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Since the ordering of symbols is not guaranteed, the solution of ode’s from ModelingToolkit is usually accessed by name. However, sol\[foo\] only gives a vector (against sol.t). How to find the index of some variable foo i…

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## [What do you need from a distributed computation framework?](https://discourse.julialang.org/t/what-do-you-need-from-a-distributed-computation-framework/55676)

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**Author:** [@dfdx](https://discourse.julialang.org/u/dfdx)\
**Replies:** 1\
**Last updated:** [July 20, 2021, 11:30pm UTC](https://discourse.julialang.org/t/what-do-you-need-from-a-distributed-computation-framework/55676 "2021-07-20T23:30:26Z")

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Recently I was thinking about adding UDF support to Spark.jl - a Julia bindings for Apache Spark. UDFs is how you run custom functions on distributed datasets in Python and Scala nowadays. However, adding them to Julia t…

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## [Calling Julia from EMTDC/PSCAD or MATLAB code](https://discourse.julialang.org/t/calling-julia-from-emtdc-pscad-or-matlab-code/52417)

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**Author:** [@anchasatish](https://discourse.julialang.org/u/anchasatish)\
**Replies:** 5\
**Last updated:** [July 20, 2021, 9:52pm UTC](https://discourse.julialang.org/t/calling-julia-from-emtdc-pscad-or-matlab-code/52417 "2021-07-20T21:52:20Z")

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I would like to use Julia programming as a software in loop for my EMTDC/PSCAD or MATLAB simulation i.e., optimization problem solved in julia and output of this optimization solution is given to the Simulation platform …

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## [NamedTuple with explicit (abstract) types](https://discourse.julialang.org/t/namedtuple-with-explicit-abstract-types/65000)

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**Author:** [@Uroc327](https://discourse.julialang.org/u/Uroc327)\
**Replies:** 3\
**Last updated:** [July 20, 2021, 7:04pm UTC](https://discourse.julialang.org/t/namedtuple-with-explicit-abstract-types/65000 "2021-07-20T19:04:41Z")

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How can I create a NamedTuple with an abstract type? When I try the following code, nt.a is of concrete type Vector{Float64} and the assignment nt.a\[\] = arr fails because a Matrix{Int64} cannot be converted to a Vector{…

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## [Mutable sorted collections](https://discourse.julialang.org/t/mutable-sorted-collections/64938)

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**Author:** [@Mark\_Nahabedian](https://discourse.julialang.org/u/Mark_Nahabedian)\
**Replies:** 7\
**Last updated:** [July 20, 2021, 6:13pm UTC](https://discourse.julialang.org/t/mutable-sorted-collections/64938 "2021-07-20T18:13:07Z")

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I don’t understand what the use case for SortedSet is. It seems to only collect and sort keys, with no values associated with those keys. I have a homogeneous collection of structs (points of a parameterized curve in a …

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## [Is it safe to run this code in multithread way: modify the same data frame in loop](https://discourse.julialang.org/t/is-it-safe-to-run-this-code-in-multithread-way-modify-the-same-data-frame-in-loop/64896)

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**Author:** [@BMval](https://discourse.julialang.org/u/BMval)\
**Replies:** 3\
**Last updated:** [July 20, 2021, 5:59pm UTC](https://discourse.julialang.org/t/is-it-safe-to-run-this-code-in-multithread-way-modify-the-same-data-frame-in-loop/64896 "2021-07-20T17:59:21Z")

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I wonder, is it safe to modify the same Data Frame in a multithread loop? @threads for i in 1:size(df)\[1\] df.column\[i\] = some\_function(…) end Thank you in advance. Best

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## [Using cppyy for julia/C++ interoperability](https://discourse.julialang.org/t/using-cppyy-for-julia-c-interoperability/63979)

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**Author:** [@kfjahnke](https://discourse.julialang.org/u/kfjahnke)\
**Replies:** 34\
**Last updated:** [July 20, 2021, 4:56pm UTC](https://discourse.julialang.org/t/using-cppyy-for-julia-c-interoperability/63979 "2021-07-20T16:56:02Z")

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Browsing the julia universe, I found interpolations.jl, which offers b-spline interpolation. I am the author of a comprehensive C++ b-spline library, so I thought I’d post a greeting issue to the colleagues and point the…

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