# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1541

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

**Page:** 1542

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## [NestedStructInitialiser.jl](https://discourse.julialang.org/t/nestedstructinitialiser-jl/52159)

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**Author:** [@jbrea](https://discourse.julialang.org/u/jbrea)\
**Replies:** 0\
**Last updated:** [December 21, 2020, 8:43am UTC](https://discourse.julialang.org/t/nestedstructinitialiser-jl/52159 "2020-12-21T08:43:18Z")

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If this is useful for somebody else, I’ll register it. From the README: NestedStructInitialiser exports two functions: parameters helps to explore nested structures and initialiser creates efficient constructors for…

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## [Makie GLFWError](https://discourse.julialang.org/t/makie-glfwerror/51006)

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**Author:** [@arnief3](https://discourse.julialang.org/u/arnief3)\
**Replies:** 6\
**Last updated:** [December 21, 2020, 8:40am UTC](https://discourse.julialang.org/t/makie-glfwerror/51006 "2020-12-21T08:40:55Z")

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I am attempting to use Makie for the first time but I am getting the following error: ERROR: GLFWError (VERSION\_UNAVAILABLE): GLX: Failed to create context: BadValue I have tried to run some of the Makie examples and a…

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## [Replacing missing values in dataframe-convert-type-union-float64-is-ambiguous](https://discourse.julialang.org/t/replacing-missing-values-in-dataframe-convert-type-union-float64-is-ambiguous/52119)

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**Author:** [@new\_julia\_enthusiast](https://discourse.julialang.org/u/new_julia_enthusiast)\
**Replies:** 6\
**Last updated:** [December 21, 2020, 4:19am UTC](https://discourse.julialang.org/t/replacing-missing-values-in-dataframe-convert-type-union-float64-is-ambiguous/52119 "2020-12-21T04:19:59Z")

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Hi, I am a new Julia user and I am having difficulty imputing missing values in my dataframe. The replacement value is dependent on the position of the column and other values in that row. Coming from a Java background, …

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## [Julia equivalent of the Python \`slice\` class](https://discourse.julialang.org/t/julia-equivalent-of-the-python-slice-class/52152)

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**Author:** [@Krastanov](https://discourse.julialang.org/u/Krastanov)\
**Replies:** 4\
**Last updated:** [December 21, 2020, 3:10am UTC](https://discourse.julialang.org/t/julia-equivalent-of-the-python-slice-class/52152 "2020-12-21T03:10:02Z")

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In Python I can store an index range into a variable and reuse it. In particular, I can store a range with implicit begin-at-0 and end-at-end-of-list extremas. How do I do the following in Julia: my\_list = \[1,2,3,4,5,6…

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## [Push into array of arrays does not work when type is specified](https://discourse.julialang.org/t/push-into-array-of-arrays-does-not-work-when-type-is-specified/52151)

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**Author:** [@ZdM87](https://discourse.julialang.org/u/ZdM87)\
**Replies:** 1\
**Last updated:** [December 21, 2020, 2:20am UTC](https://discourse.julialang.org/t/push-into-array-of-arrays-does-not-work-when-type-is-specified/52151 "2020-12-21T02:20:02Z")

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Why the following code works using Combinatorics all\_sequences = \[\] for i in 2:4 for j in permutations(1:4, i) push!(all\_sequences, collect(j)) end end and this one does not using Combinatorics all\_s…

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## [Where are the LaTex equations in plots coming from?](https://discourse.julialang.org/t/where-are-the-latex-equations-in-plots-coming-from/52148)

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**Author:** [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Replies:** 3\
**Last updated:** [December 21, 2020, 1:42am UTC](https://discourse.julialang.org/t/where-are-the-latex-equations-in-plots-coming-from/52148 "2020-12-21T01:42:06Z")

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Hi, How do packages like GR and likely others used by Plots manage to display LaTex equations without installing the Tex/LaTex package? Is there a really minimal LaTex installation that is used under the hood? Tanks.

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## [Very simple code, why would there be performance problems](https://discourse.julialang.org/t/very-simple-code-why-would-there-be-performance-problems/51848)

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**Author:** [@Zq\_F](https://discourse.julialang.org/u/Zq_F)\
**Replies:** 12\
**Last updated:** [December 21, 2020, 1:25am UTC](https://discourse.julialang.org/t/very-simple-code-why-would-there-be-performance-problems/51848 "2020-12-21T01:25:21Z")

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Hello, everyone Very simple code, the speed is really slow, I suspect that the method of using Ref in the structure is wrong Everyone, please take a look, thank you mutable struct T3 f1::Int64 f2::String f3::Fl…

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## [Abstract type hierarchies along with OOP constructed types](https://discourse.julialang.org/t/abstract-type-hierarchies-along-with-oop-constructed-types/52100)

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**Author:** [@emmettgb](https://discourse.julialang.org/u/emmettgb)\
**Replies:** 5\
**Last updated:** [December 21, 2020, 12:54am UTC](https://discourse.julialang.org/t/abstract-type-hierarchies-along-with-oop-constructed-types/52100 "2020-12-21T00:54:05Z")

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Hi guys, I am new to Julia’s Discourse, but rather familiar with Julia. I maintain a package called Lathe.jl which is an object-oriented machine-learning package in Julia with syntax similar to SkLearn. As such, for an e…

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## [Creating a matrix from array of arrays without changing order of dimensions](https://discourse.julialang.org/t/creating-a-matrix-from-array-of-arrays-without-changing-order-of-dimensions/52143)

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**Author:** [@Tobias-Thomas](https://discourse.julialang.org/u/Tobias-Thomas)\
**Replies:** 5\
**Last updated:** [December 20, 2020, 8:56pm UTC](https://discourse.julialang.org/t/creating-a-matrix-from-array-of-arrays-without-changing-order-of-dimensions/52143 "2020-12-20T20:56:58Z")

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As far as I know the way in julia to create a 2D-Matrix from an Array of 1D-arrays is to use hcat(a...). My problem now is that it seems that julia’s column-major style of arrays changes the order of dimensions. a = \[\[1…

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## [Is sum function broken?](https://discourse.julialang.org/t/is-sum-function-broken/52146)

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**Author:** [@acastrauss](https://discourse.julialang.org/u/acastrauss)\
**Replies:** 3\
**Last updated:** [December 20, 2020, 8:25pm UTC](https://discourse.julialang.org/t/is-sum-function-broken/52146 "2020-12-20T20:25:35Z")

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Recently installed version 1.5.3 and I get this error when trying sum function: Also tried with dot (‘.’) and with dims as second argument, but nothing worked. prod(A) would work for example Does anyone have an idea…

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## [Sorting: use of keyword by and lt](https://discourse.julialang.org/t/sorting-use-of-keyword-by-and-lt/52116)

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**Author:** [@rocco\_sprmnt21](https://discourse.julialang.org/u/rocco_sprmnt21)\
**Replies:** 8\
**Last updated:** [December 20, 2020, 2:51pm UTC](https://discourse.julialang.org/t/sorting-use-of-keyword-by-and-lt/52116 "2020-12-20T14:51:26Z")

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I tried to solve the problem proposed here using the function SORT() with the BY and LT keywords. In particular I tried with the following dataframe and expression: df = DataFrame(NAME = \["A1","A1","A2", "A1","A2","A…

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## [MethodError for function calling with an argument a parametric composite type (struct)](https://discourse.julialang.org/t/methoderror-for-function-calling-with-an-argument-a-parametric-composite-type-struct/52101)

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**Author:** [@mocalvao](https://discourse.julialang.org/u/mocalvao)\
**Replies:** 5\
**Last updated:** [December 20, 2020, 2:09pm UTC](https://discourse.julialang.org/t/methoderror-for-function-calling-with-an-argument-a-parametric-composite-type-struct/52101 "2020-12-20T14:09:07Z")

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Hi there I have the following code, which, if necessary I might strip down. using Parameters using Unitful @with\_kw struct EosConst{T\<:Real} w\_0::T = -1.0 end @with\_kw struct EosCPL{T\<:Real} w\_0::T = -1 …

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## [Logging inside Docker container vscode](https://discourse.julialang.org/t/logging-inside-docker-container-vscode/52130)

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**Author:** [@Telcrome](https://discourse.julialang.org/u/Telcrome)\
**Replies:** 0\
**Last updated:** [December 20, 2020, 1:45pm UTC](https://discourse.julialang.org/t/logging-inside-docker-container-vscode/52130 "2020-12-20T13:45:51Z")

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When using Julia inside the official docker container (WSL2 backend), logging does not work inside the vscode debugger. It does work when using the integrated terminal directly. Test code: @info "test" @error "test" @w…

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## [Custom array index, multiple index one value](https://discourse.julialang.org/t/custom-array-index-multiple-index-one-value/52041)

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**Author:** [@Atomtomate](https://discourse.julialang.org/u/Atomtomate)\
**Replies:** 4\
**Last updated:** [December 20, 2020, 1:32pm UTC](https://discourse.julialang.org/t/custom-array-index-multiple-index-one-value/52041 "2020-12-20T13:32:38Z")

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Hello there, my question is about the optimal way to realize the following data structure in Julia: I have a couple of very large rank 4 arrays from a numerical simulation. Typical, these have around 500^4 complex valu…

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## [Warping an image to polar coordinates](https://discourse.julialang.org/t/warping-an-image-to-polar-coordinates/29084)

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**Author:** [@hans](https://discourse.julialang.org/u/hans)\
**Replies:** 9\
**Last updated:** [December 20, 2020, 11:06am UTC](https://discourse.julialang.org/t/warping-an-image-to-polar-coordinates/29084 "2020-12-20T11:06:46Z")

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Hi, I’m trying to map an image from cartesian coordinates to polar coordinates (i.e. have the center pixel along the left edge and the outside pixels along the right edge with some pixels warped from outside the image). …

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## [Conditional use of modules and macros](https://discourse.julialang.org/t/conditional-use-of-modules-and-macros/51118)

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**Author:** [@paulmelis](https://discourse.julialang.org/u/paulmelis)\
**Replies:** 4\
**Last updated:** [December 20, 2020, 10:04am UTC](https://discourse.julialang.org/t/conditional-use-of-modules-and-macros/51118 "2020-12-20T10:04:47Z")

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It seems using a module can be done at arbitrary places within source files, even in conditional blocks, without too much trouble, except for when a module provides a macro that you would otherwise use. For example, this…

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## [Surfc equivalent? Plotting contour underneath surfacep plot](https://discourse.julialang.org/t/surfc-equivalent-plotting-contour-underneath-surfacep-plot/52108)

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**Author:** [@jg-854](https://discourse.julialang.org/u/jg-854)\
**Replies:** 2\
**Last updated:** [December 20, 2020, 2:44am UTC](https://discourse.julialang.org/t/surfc-equivalent-plotting-contour-underneath-surfacep-plot/52108 "2020-12-20T02:44:13Z")

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MATLAB has this feature which allows you to plot a contour plot underneath a surface plot of a function. I would like to recreate this in JULIA. If I used contour!() after surface(), this doesn’t seem to work… Thanks! …

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## [Comparing Unequal Dictionaries](https://discourse.julialang.org/t/comparing-unequal-dictionaries/52048)

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**Author:** [@SergeantMike67](https://discourse.julialang.org/u/SergeantMike67)\
**Replies:** 7\
**Last updated:** [December 19, 2020, 10:29pm UTC](https://discourse.julialang.org/t/comparing-unequal-dictionaries/52048 "2020-12-19T22:29:52Z")

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So after reading about everything I can find on the subject, I am going to throw in the towel and ask. I have 2 dictionaries “a” and “b” a = 4-element Array{Pair{Union{Missing, Int16},Int64},1}: 133 =\> 2 135 =\> 9 13…

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## [How to specify point vs fill for Geom.point in Gadfly?](https://discourse.julialang.org/t/how-to-specify-point-vs-fill-for-geom-point-in-gadfly/52097)

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**Author:** [@mkarikom](https://discourse.julialang.org/u/mkarikom)\
**Replies:** 3\
**Last updated:** [December 19, 2020, 10:12pm UTC](https://discourse.julialang.org/t/how-to-specify-point-vs-fill-for-geom-point-in-gadfly/52097 "2020-12-19T22:12:53Z")

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In the gallery example here we have: using Gadfly, RDatasets set\_default\_plot\_size(21cm, 8cm) p1 = plot(dataset("MASS", "mammals"), x="Body", y="Brain", label=1, Scale.x\_log10, Scale.y\_log10, Geom.point, Geom.label…

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## [Cannot plot in interactive mode](https://discourse.julialang.org/t/cannot-plot-in-interactive-mode/52111)

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**Author:** [@nikolasborrel](https://discourse.julialang.org/u/nikolasborrel)\
**Replies:** 0\
**Last updated:** [December 19, 2020, 11:45pm UTC](https://discourse.julialang.org/t/cannot-plot-in-interactive-mode/52111 "2020-12-19T23:45:24Z")

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I’m struggling with plotting in interactive mode in VS Code (without Jupyter Lab). According to Backends · Plots, Plotly(JS), PyPlot, InspectDR are most suitable. I’m plotting surface plots of triangles: x, y and z are …

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## [Groupby / reshaping dataframe with unique values](https://discourse.julialang.org/t/groupby-reshaping-dataframe-with-unique-values/51149)

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**Author:** [@Smith](https://discourse.julialang.org/u/Smith)\
**Replies:** 17\
**Last updated:** [December 19, 2020, 11:22pm UTC](https://discourse.julialang.org/t/groupby-reshaping-dataframe-with-unique-values/51149 "2020-12-19T23:22:29Z")

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How can I rearrange a dataframe so that values of a particular column that are repeated appear only once and the related data is transposed to columns? Suppose I have a dataframe given by: df1 = DataFrame(NAME = \["A1"…

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## [How fast ist a binary file from packagecomplier.jl and what is its file size](https://discourse.julialang.org/t/how-fast-ist-a-binary-file-from-packagecomplier-jl-and-what-is-its-file-size/51415)

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**Author:** [@boroboro77](https://discourse.julialang.org/u/boroboro77)\
**Replies:** 3\
**Last updated:** [December 19, 2020, 11:20pm UTC](https://discourse.julialang.org/t/how-fast-ist-a-binary-file-from-packagecomplier-jl-and-what-is-its-file-size/51415 "2020-12-19T23:20:03Z")

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Hello, If I create a binary file using packagecompliler.jl, will the code be as (or almost as) fast as a C++ binary file? Or are there any hidden performance issues? If I use any external library, will the size of the…

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## [Clearest Julia stacktrace library](https://discourse.julialang.org/t/clearest-julia-stacktrace-library/52104)

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**Author:** [@Marcell\_Havlik](https://discourse.julialang.org/u/Marcell_Havlik)\
**Replies:** 3\
**Last updated:** [December 19, 2020, 11:02pm UTC](https://discourse.julialang.org/t/clearest-julia-stacktrace-library/52104 "2020-12-19T23:02:40Z")

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Hey, I saw this stacktrace library but this is left alone: https://github.com/jkrumbiegel/ClearStacktrace.jl What custom stacktrace do you guys use? I find ClearStacktrace very good but I ran into some situation when…

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## [Trouble installing/setting up Julia 1.5.3](https://discourse.julialang.org/t/trouble-installing-setting-up-julia-1-5-3/52096)

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**Author:** [@Michael\_Barmann](https://discourse.julialang.org/u/Michael_Barmann)\
**Replies:** 12\
**Last updated:** [December 19, 2020, 7:20pm UTC](https://discourse.julialang.org/t/trouble-installing-setting-up-julia-1-5-3/52096 "2020-12-19T19:20:34Z")

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I am a new user and am having trouble setting up Julia 1.5.3., despite following the instructions here: Installation Instructions · Juno Documentation. (I am using Windows 10 and I downloaded 64-bit (installer). I made i…

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## [Unable to optimize using Alpine.jl](https://discourse.julialang.org/t/unable-to-optimize-using-alpine-jl/52088)

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**Author:** [@hassanis](https://discourse.julialang.org/u/hassanis)\
**Replies:** 2\
**Last updated:** [December 19, 2020, 6:48pm UTC](https://discourse.julialang.org/t/unable-to-optimize-using-alpine-jl/52088 "2020-12-19T18:48:15Z")

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I’m havinng trouble using Alpine.jl. I know that it’s compatible with MOI now, and the new version was presented at INFORMS this year. Yet, when I try using it, I get the following error: MethodError: no method matching…

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## [Constrained type parameters](https://discourse.julialang.org/t/constrained-type-parameters/50263)

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**Author:** [@eckofoid](https://discourse.julialang.org/u/eckofoid)\
**Replies:** 6\
**Last updated:** [December 19, 2020, 6:36pm UTC](https://discourse.julialang.org/t/constrained-type-parameters/50263 "2020-12-19T18:36:21Z")

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When defining a type, is it possible to place a constraint on parameter values? For example, consider the following simple type definition: struct Orf start::Int32 stop::Int32 pol::Int8 end Is there any way to…

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## [WGLMakie animations?](https://discourse.julialang.org/t/wglmakie-animations/52084)

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**Author:** [@LaurentPlagne](https://discourse.julialang.org/u/LaurentPlagne)\
**Replies:** 5\
**Last updated:** [December 19, 2020, 4:55pm UTC](https://discourse.julialang.org/t/wglmakie-animations/52084 "2020-12-19T16:55:00Z")

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Hi, I use (GL)Makie for animations. When I replace using GLMakie with using WGLMakie its fails: ERROR: type GenericIOBuffer has no field io Is it possible to display animations via WGLMakie ? Is there an example avai…

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## [SIMD and compiled code](https://discourse.julialang.org/t/simd-and-compiled-code/52082)

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**Author:** [@lungben](https://discourse.julialang.org/u/lungben)\
**Replies:** 5\
**Last updated:** [December 19, 2020, 4:33pm UTC](https://discourse.julialang.org/t/simd-and-compiled-code/52082 "2020-12-19T16:33:14Z")

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Hi, Different processors have different SIMD capabilities, especially different vector sizes on which the processor can work at once. However, there are a few points w.r.t. code compilation which I am not sure about. I…

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## [Method Error: No mathching method when using ContinuousDynamicalSystem](https://discourse.julialang.org/t/method-error-no-mathching-method-when-using-continuousdynamicalsystem/52040)

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**Author:** [@Gary\_McCormack](https://discourse.julialang.org/u/Gary_McCormack)\
**Replies:** 7\
**Last updated:** [December 19, 2020, 4:31pm UTC](https://discourse.julialang.org/t/method-error-no-mathching-method-when-using-continuousdynamicalsystem/52040 "2020-12-19T16:31:56Z")

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Hi everyone, I’m very new to Julia and trying to wrap my head around the following error. This is a stripped-down version of the ODE I am trying to wrap as a Continuous Dynamical System. using DifferentialEquations usi…

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## [Numerical continuation and periodic orbits](https://discourse.julialang.org/t/numerical-continuation-and-periodic-orbits/51580)

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**Author:** [@cadojo](https://discourse.julialang.org/u/cadojo)\
**Replies:** 11\
**Last updated:** [December 19, 2020, 3:08pm UTC](https://discourse.julialang.org/t/numerical-continuation-and-periodic-orbits/51580 "2020-12-19T15:08:07Z")

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Apologies if this question is poorly worded, I’m very new to numerical continuation and nonlinear frequency analysis. I have a nonlinear system of ODEs, and I’d like to numerically find periodic solutions for a changing …

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