# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1105

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

**Page:** 1106

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## [How to analyze the solution?](https://discourse.julialang.org/t/how-to-analyze-the-solution/77395)

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**Author:** [@egor](https://discourse.julialang.org/u/egor)\
**Replies:** 1\
**Last updated:** [March 4, 2022, 11:07am UTC](https://discourse.julialang.org/t/how-to-analyze-the-solution/77395 "2022-03-04T11:07:31Z")

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Hello everyone, I recently switched to julia from python and ran into a problem. I solve a parameterized system: Γ(x, λ, Θ) = 1 / (1 + exp(-λ\*(x - Θ))) function parametrized\_2hr!(du, u, p, t) a = p\[1\]; b = p\[2\]; c…

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## [Modifying elements of a Matrix](https://discourse.julialang.org/t/modifying-elements-of-a-matrix/77381)

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**Author:** [@Kuldeep](https://discourse.julialang.org/u/Kuldeep)\
**Replies:** 3\
**Last updated:** [March 4, 2022, 6:27am UTC](https://discourse.julialang.org/t/modifying-elements-of-a-matrix/77381 "2022-03-04T06:27:37Z")

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\#####Example 1################# a=rand(2,2) b=a b=ones(size(a)) a #####Example 2######################### a=rand(2,2) b=a b\[1:4\].=1.0 a Q- Why do we get different results ? In example 1, “a” is not equal to…

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## [ArgumentError: no outer repetition count may be negative; got (-1,)](https://discourse.julialang.org/t/argumenterror-no-outer-repetition-count-may-be-negative-got-1/77384)

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**Author:** [@bbokser](https://discourse.julialang.org/u/bbokser)\
**Replies:** 4\
**Last updated:** [March 4, 2022, 2:21am UTC](https://discourse.julialang.org/t/argumenterror-no-outer-repetition-count-may-be-negative-got-1/77384 "2022-03-04T02:21:25Z")

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I have received the following error, and could not find any explanation for its meaning in Google search results. ArgumentError: no outer repetition count may be negative; got (-1,) Stacktrace: \[1\] check @ ./abstra…

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## [JuMP: Sensitivity of Objective to Constraints](https://discourse.julialang.org/t/jump-sensitivity-of-objective-to-constraints/77361)

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**Author:** [@Alec\_Loudenback](https://discourse.julialang.org/u/Alec_Loudenback)\
**Replies:** 3\
**Last updated:** [March 4, 2022, 1:51am UTC](https://discourse.julialang.org/t/jump-sensitivity-of-objective-to-constraints/77361 "2022-03-04T01:51:52Z")

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Is there a recommended way to perform sensitivity analysis of the optimization target to different constraints? What I mean by that is a way to determine which constraints are most limiting to the objective function. Fo…

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## [How to solve regression problem with no related data each other](https://discourse.julialang.org/t/how-to-solve-regression-problem-with-no-related-data-each-other/77350)

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**Author:** [@RickandMortyforever](https://discourse.julialang.org/u/RickandMortyforever)\
**Replies:** 5\
**Last updated:** [March 4, 2022, 1:21am UTC](https://discourse.julialang.org/t/how-to-solve-regression-problem-with-no-related-data-each-other/77350 "2022-03-04T01:21:01Z")

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This is more of a problem solving question rather than programming. I’ll delete this post if it is not appropriate. I am trying to solve a regression problem. And I looked at scatter plot that is frustrating me. …

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## [Juno Error "Can't resolve version"](https://discourse.julialang.org/t/juno-error-cant-resolve-version/77373)

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**Author:** [@Dustin\_Hess](https://discourse.julialang.org/u/Dustin_Hess)\
**Replies:** 7\
**Last updated:** [March 3, 2022, 10:44pm UTC](https://discourse.julialang.org/t/juno-error-cant-resolve-version/77373 "2022-03-03T22:44:08Z")

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I am using Manjaro Gnome. I updated to Julia 1.7.2 for some reason this broke Juno. I have completely purged my system of all prior Julia versions and added Julia to my PATH even though pamac does this already. Any help …

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## [Pass function arguments in tuple, how to manage keyword arguments](https://discourse.julialang.org/t/pass-function-arguments-in-tuple-how-to-manage-keyword-arguments/21034)

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**Author:** [@Adriel](https://discourse.julialang.org/u/Adriel)\
**Replies:** 5\
**Last updated:** [March 3, 2022, 9:31pm UTC](https://discourse.julialang.org/t/pass-function-arguments-in-tuple-how-to-manage-keyword-arguments/21034 "2022-03-03T21:31:55Z")

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I have a function with some optional keyword arguments. function f1(a::Int, b::Float64; c::Int=42, d::Int=43) Another top level function may sometimes call f1, but I don’t want to bother the user with specifying f1’s a…

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## [How to upgrade code for a symmetric distance matrix from julia-1.0 to julia-1.6](https://discourse.julialang.org/t/how-to-upgrade-code-for-a-symmetric-distance-matrix-from-julia-1-0-to-julia-1-6/77302)

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**Author:** [@jjdegruijter](https://discourse.julialang.org/u/jjdegruijter)\
**Replies:** 17\
**Last updated:** [March 3, 2022, 9:11pm UTC](https://discourse.julialang.org/t/how-to-upgrade-code-for-a-symmetric-distance-matrix-from-julia-1-0-to-julia-1-6/77302 "2022-03-03T21:11:04Z")

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As part of my code for julia-1.6 I try to calculate an NxN symmetric ‘distance’ matrix, where ‘distance’ is a function of 4 vectors (extracted as columns from a DataFrame),and two parameters (‘R2’ and ‘range’). While th…

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## [What are the options of hosting jupyter notebooks with Julia kernels?](https://discourse.julialang.org/t/what-are-the-options-of-hosting-jupyter-notebooks-with-julia-kernels/77332)

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**Author:** [@Xing\_Shi\_Cai](https://discourse.julialang.org/u/Xing_Shi_Cai)\
**Replies:** 1\
**Last updated:** [March 3, 2022, 8:48pm UTC](https://discourse.julialang.org/t/what-are-the-options-of-hosting-jupyter-notebooks-with-julia-kernels/77332 "2022-03-03T20:48:01Z")

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I am teaching a Linear Algebra course now. To show students vectors in 3d-space, I created some interactive 3D plots with Julia and jupyter notebooks. I wonder if there is a way that I can host the notebooks so my studen…

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## [Specific fractions w/ LaTeXStrings](https://discourse.julialang.org/t/specific-fractions-w-latexstrings/77355)

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**Author:** [@met-j](https://discourse.julialang.org/u/met-j)\
**Replies:** 6\
**Last updated:** [March 3, 2022, 8:32pm UTC](https://discourse.julialang.org/t/specific-fractions-w-latexstrings/77355 "2022-03-03T20:32:57Z")

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I am not fully satisfied with the text I can produce with LaTeXStrings. Some (/many) commands only produce a question mark. Which LaTeX commands are available? Is it possible to load LaTeX packages? LaTeX has support…

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## [Colorbar\_title position & orientation](https://discourse.julialang.org/t/colorbar-title-position-orientation/42715)

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**Author:** [@met-j](https://discourse.julialang.org/u/met-j)\
**Replies:** 4\
**Last updated:** [March 3, 2022, 7:15pm UTC](https://discourse.julialang.org/t/colorbar-title-position-orientation/42715 "2022-03-03T19:15:02Z")

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When dealing with several 2.5 d plots at the same time, it’s nice to indicate what the colorbar stands for. To do so, we have the colorbar\_title attribute, now even supported by GR. I assume, with long titles in mind, i…

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## [Error EBUSY on saving JLD2 file using Julia-1.3.0-rc2](https://discourse.julialang.org/t/error-ebusy-on-saving-jld2-file-using-julia-1-3-0-rc2/29228)

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**Author:** [@alkoedl](https://discourse.julialang.org/u/alkoedl)\
**Replies:** 13\
**Last updated:** [March 3, 2022, 7:07pm UTC](https://discourse.julialang.org/t/error-ebusy-on-saving-jld2-file-using-julia-1-3-0-rc2/29228 "2022-03-03T19:07:23Z")

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I’m getting the following error when trying to save a file in JLD2 format on Julia-1.3.0-rc2: $ C:/Users/blabla/AppData/Local/Julia-1.3.0-rc2/bin/julia.exe \[ Info: loading C:\\Users\\blabla\\.julia\\config\\startup.jl …

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## [Source code of a function](https://discourse.julialang.org/t/source-code-of-a-function/4499)

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**Author:** [@rcnlee](https://discourse.julialang.org/u/rcnlee)\
**Replies:** 20\
**Last updated:** [March 3, 2022, 6:40pm UTC](https://discourse.julialang.org/t/source-code-of-a-function/4499 "2022-03-03T18:40:10Z")

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Hello, Is it possible to recover the source code of a function as a string? For example, f(x,y) = 2sin(x+y)+1 Is there a function call on f that can get me s="2sin(x+y)+1"? Thanks!

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## [Mapreduce, pass extra arguments to reduce/vcat of DataFrames](https://discourse.julialang.org/t/mapreduce-pass-extra-arguments-to-reduce-vcat-of-dataframes/77347)

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**Author:** [@baptnz](https://discourse.julialang.org/u/baptnz)\
**Replies:** 10\
**Last updated:** [March 3, 2022, 5:30pm UTC](https://discourse.julialang.org/t/mapreduce-pass-extra-arguments-to-reduce-vcat-of-dataframes/77347 "2022-03-03T17:30:35Z")

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I’m using a map+reduce combination to apply a function returning a DataFrame and combine all the results with vcat, f(p) = DataFrame(x = collect(1:10), y = p\[1\]\*rand(10), z = p\[2\]\*rand(10)) tmp = map(f, (\[1,2\], \[3,4\],…

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## [Library of string validators and sanitizers](https://discourse.julialang.org/t/library-of-string-validators-and-sanitizers/77252)

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**Author:** [@iskyd](https://discourse.julialang.org/u/iskyd)\
**Replies:** 17\
**Last updated:** [March 3, 2022, 5:18pm UTC](https://discourse.julialang.org/t/library-of-string-validators-and-sanitizers/77252 "2022-03-03T17:18:33Z")

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Hi everyone, I was inspired by validator.js that I’ve used a lot in javascript. I didn’t find anything similar in Julia, so I started developing validator.jl. I think that this could be useful considering also the expan…

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## [NaiveBayes.jl alternative?](https://discourse.julialang.org/t/naivebayes-jl-alternative/77371)

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**Author:** [@compleat](https://discourse.julialang.org/u/compleat)\
**Replies:** 0\
**Last updated:** [March 3, 2022, 5:17pm UTC](https://discourse.julialang.org/t/naivebayes-jl-alternative/77371 "2022-03-03T17:17:35Z")

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This looks like it was a neat package but no longer works with its own examples which haven’t been updated since 2016. Does anyone know of an alternative package that does the same thing? Thanks for any help.

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## [\[ANN\] CoolProp.jl 0.1](https://discourse.julialang.org/t/ann-coolprop-jl-0-1/77368)

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**Author:** [@barche](https://discourse.julialang.org/u/barche)\
**Replies:** 0\
**Last updated:** [March 3, 2022, 4:33pm UTC](https://discourse.julialang.org/t/ann-coolprop-jl-0-1/77368 "2022-03-03T16:33:10Z")

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Hi all, The CoolProp.jl wrapper for the CoolProp fluids properties library has been around for a while, but now the package is registered and installable from the General repository. I’d like to highlight a new feature,…

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## [What exactly is a \`Number\`?](https://discourse.julialang.org/t/what-exactly-is-a-number/77331)

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**Author:** [@matthias314](https://discourse.julialang.org/u/matthias314)\
**Replies:** 8\
**Last updated:** [March 3, 2022, 3:47pm UTC](https://discourse.julialang.org/t/what-exactly-is-a-number/77331 "2022-03-03T15:47:14Z")

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Suppose I want to implement some “numbers” (which should at least be a ring in the mathematical sense) in Julia. The documentation says that Number is the abstract supertype for all number types. Does Julia put any assum…

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## [Can't call struct constructor inside of a function](https://discourse.julialang.org/t/cant-call-struct-constructor-inside-of-a-function/77359)

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**Author:** [@the\_dude](https://discourse.julialang.org/u/the_dude)\
**Replies:** 2\
**Last updated:** [March 3, 2022, 2:20pm UTC](https://discourse.julialang.org/t/cant-call-struct-constructor-inside-of-a-function/77359 "2022-03-03T14:20:29Z")

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I have this struct created in a file: I’m including it on another file using: But, when a try to call the constructor of the struct inside of a function like this: I get this error: ERROR: LoadError: UndefVa…

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## [What does it mean for the cluster to return "qsub: use proper select statement"](https://discourse.julialang.org/t/what-does-it-mean-for-the-cluster-to-return-qsub-use-proper-select-statement/77339)

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**Author:** [@pafloxy](https://discourse.julialang.org/u/pafloxy)\
**Replies:** 2\
**Last updated:** [March 3, 2022, 2:13pm UTC](https://discourse.julialang.org/t/what-does-it-mean-for-the-cluster-to-return-qsub-use-proper-select-statement/77339 "2022-03-03T14:13:30Z")

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I was trying to run a simple helloworld program in julia on HPC, using PBS script submission but it ended with followoing message ~~ qsub: use proper select statement

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## [Source Code Quality Assurance / Linting](https://discourse.julialang.org/t/source-code-quality-assurance-linting/66599)

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**Author:** [@Jan\_Dolinsky](https://discourse.julialang.org/u/Jan_Dolinsky)\
**Replies:** 3\
**Last updated:** [March 3, 2022, 1:44pm UTC](https://discourse.julialang.org/t/source-code-quality-assurance-linting/66599 "2022-03-03T13:44:55Z")

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Hello, I would like to enable a git hook for some basic quality assurance of our development efforts in Julia. In particular, I would like to check for line is not longer than C characters function is not longer than …

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## [Can't quote a Cmd with equals sign correctly](https://discourse.julialang.org/t/cant-quote-a-cmd-with-equals-sign-correctly/65963)

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**Author:** [@moble](https://discourse.julialang.org/u/moble)\
**Replies:** 6\
**Last updated:** [March 3, 2022, 12:26pm UTC](https://discourse.julialang.org/t/cant-quote-a-cmd-with-equals-sign-correctly/65963 "2022-03-03T12:26:09Z")

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I’ve been happily using DrWatson for my latest project, using its convention for filenames. For example, if my simulation uses parameters Dict(:a=\>2, :b=\>7), my output data file might be named simulation\_a=2\_b=7.h5. Bu…

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## [Mismatch between LLVM library used during precompilation (Atom - Juno)](https://discourse.julialang.org/t/mismatch-between-llvm-library-used-during-precompilation-atom-juno/77352)

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**Author:** [@Volker](https://discourse.julialang.org/u/Volker)\
**Replies:** 0\
**Last updated:** [March 3, 2022, 12:28pm UTC](https://discourse.julialang.org/t/mismatch-between-llvm-library-used-during-precompilation-atom-juno/77352 "2022-03-03T12:28:25Z")

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Hello, I get the following error when I evaluate using MyModule via Atom - Juno. Somehow I don’t get this error when I evaluate it via julia.exe or VsCode. I make the module available via \`push!(LOAD\_PATH, \<mymodule\_pat…

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## [Parameter estimation with DifferentialEquations.jl for a subset of parameters](https://discourse.julialang.org/t/parameter-estimation-with-differentialequations-jl-for-a-subset-of-parameters/33851)

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**Author:** [@moesphere](https://discourse.julialang.org/u/moesphere)\
**Replies:** 3\
**Last updated:** [March 3, 2022, 12:27pm UTC](https://discourse.julialang.org/t/parameter-estimation-with-differentialequations-jl-for-a-subset-of-parameters/33851 "2022-03-03T12:27:13Z")

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If I have defined an ODEFunction with a parameter vector p according to the DifferentialEquations.jl package. Is it possible to build a loss objective, i.e. using build\_loss\_objective for only a subset of parameters spe…

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## [Keeping a "reference" to a struct field](https://discourse.julialang.org/t/keeping-a-reference-to-a-struct-field/77344)

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**Author:** [@sstroemer](https://discourse.julialang.org/u/sstroemer)\
**Replies:** 3\
**Last updated:** [March 3, 2022, 11:28am UTC](https://discourse.julialang.org/t/keeping-a-reference-to-a-struct-field/77344 "2022-03-03T11:28:39Z")

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Edit: See my first reply below for a more correct MWE. Consider a struct like mutable struct Test a::Int end After t = Test(1) I would like to “bind” to the field so that after x = t.a t.a = 2 x will evaluate as…

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## [Error in using @threads](https://discourse.julialang.org/t/error-in-using-threads/77316)

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**Author:** [@Katasuke](https://discourse.julialang.org/u/Katasuke)\
**Replies:** 10\
**Last updated:** [March 3, 2022, 10:13am UTC](https://discourse.julialang.org/t/error-in-using-threads/77316 "2022-03-03T10:13:52Z")

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I am trying to simulate a nested model that contains many for loops. I want to use the parallel calculation to speed up the simulation. But I failed to use @threads. Here is the structure of my code: addprocs(10) v\_rep …

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## [Interact.jl PyPlot, HTML](https://discourse.julialang.org/t/interact-jl-pyplot-html/77343)

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**Author:** [@Ludovic\_Dumoulin](https://discourse.julialang.org/u/Ludovic_Dumoulin)\
**Replies:** 0\
**Last updated:** [March 3, 2022, 9:46am UTC](https://discourse.julialang.org/t/interact-jl-pyplot-html/77343 "2022-03-03T09:46:15Z")

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Hey, I use jupyter lab and julia 1.6. I have png files in a directory, and I would like (using a slider or the keyboard) to display all png files one by one. I can make a gif but I would like to explore my files forwar…

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## [Detecting non-ascii key presses?](https://discourse.julialang.org/t/detecting-non-ascii-key-presses/77148)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 4\
**Last updated:** [March 3, 2022, 8:57am UTC](https://discourse.julialang.org/t/detecting-non-ascii-key-presses/77148 "2022-03-03T08:57:56Z")

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I have some posts that can detect ascii key presses but I can’t find any resource on how to detect if keys like LEFT or RIGHT are pressed. Basically, i want to wait for input of LEFT or Right and then do something then …

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## [How to convert an "any" column in a dataframe containing strings and floats?](https://discourse.julialang.org/t/how-to-convert-an-any-column-in-a-dataframe-containing-strings-and-floats/77330)

<div class="topic-metadata">

**Author:** [@a.frist](https://discourse.julialang.org/u/a.frist)\
**Replies:** 7\
**Last updated:** [March 3, 2022, 8:06am UTC](https://discourse.julialang.org/t/how-to-convert-an-any-column-in-a-dataframe-containing-strings-and-floats/77330 "2022-03-03T08:06:27Z")

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I’m trying to convert a column of type “Any” in my dataframe to a column of type “Float64”. It seems that there are float values and string values in the column. First I tried: df\[!, :column2\] = tryparse.(Float64, df\[:…

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## [Vector{Vector{T} where T} vs Vector{Vector{T}} where T](https://discourse.julialang.org/t/vector-vector-t-where-t-vs-vector-vector-t-where-t/2743)

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**Author:** [@dfdx](https://discourse.julialang.org/u/dfdx)\
**Replies:** 18\
**Last updated:** [March 3, 2022, 7:50am UTC](https://discourse.julialang.org/t/vector-vector-t-where-t-vs-vector-vector-t-where-t/2743 "2022-03-03T07:50:00Z")

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I can see a lot of discussions around UnionAll and new where keyword on GitHub, but most comments seem to make sense only to people who track the topic for a long time. Is there any docs or drafts (except for news) about…

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