# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1443

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

**Page:** 1444

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## [How to put a timestamp in a filename on Windows?](https://discourse.julialang.org/t/how-to-put-a-timestamp-in-a-filename-on-windows/58155)

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**Author:** [@Olivier\_Merchiers](https://discourse.julialang.org/u/Olivier_Merchiers)\
**Replies:** 2\
**Last updated:** [March 29, 2021, 9:47am UTC](https://discourse.julialang.org/t/how-to-put-a-timestamp-in-a-filename-on-windows/58155 "2021-03-29T09:47:23Z")

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Hello everyone, On linux I do this very common thing of putting a timestamp in the filenames that are produced by my simulations: a=1.0 b=1.5 using Dates filename =string(now())\*"\_parameter1=$(a)\_parameter2=$(b).txt" …

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## [CartesianIndices gives different answer in Julia 1.6 and 1.5 for particular case](https://discourse.julialang.org/t/cartesianindices-gives-different-answer-in-julia-1-6-and-1-5-for-particular-case/58156)

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**Author:** [@fverdugo](https://discourse.julialang.org/u/fverdugo)\
**Replies:** 1\
**Last updated:** [March 29, 2021, 9:30am UTC](https://discourse.julialang.org/t/cartesianindices-gives-different-answer-in-julia-1-6-and-1-5-for-particular-case/58156 "2021-03-29T09:30:56Z")

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I just wanted to mention that I have noticed this change in the behavior of CartesianIndices. Which is the expected one, the new or the old? In Julia 1.5.3 julia\> CartesianIndices((2,1:3)) 1×3 CartesianIndices{2,Tuple{…

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## [Compose.jl has the radius of Forms tied to width](https://discourse.julialang.org/t/compose-jl-has-the-radius-of-forms-tied-to-width/58142)

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**Author:** [@SL6Trip](https://discourse.julialang.org/u/SL6Trip)\
**Replies:** 2\
**Last updated:** [March 29, 2021, 9:21am UTC](https://discourse.julialang.org/t/compose-jl-has-the-radius-of-forms-tied-to-width/58142 "2021-03-29T09:21:54Z")

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I was playing around with Compose.jl recently, when I realise that Forms that use a radius, such as circle have their radius tied to the width of the context window. See the two images and the code below for an example. …

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## [Problem assigning type to DataFrame](https://discourse.julialang.org/t/problem-assigning-type-to-dataframe/57966)

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**Author:** [@Nash](https://discourse.julialang.org/u/Nash)\
**Replies:** 6\
**Last updated:** [March 29, 2021, 9:19am UTC](https://discourse.julialang.org/t/problem-assigning-type-to-dataframe/57966 "2021-03-29T09:19:29Z")

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The following code results in an error: using MAT directory = "C:/MyData/" files = readdir(directory) global tournaments = Vector{String}(undef,10) for i = 1:10 event = matread(directory\*files\[i\]) tournament…

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## [Why is there memory allocation and time difference in @views and view?](https://discourse.julialang.org/t/why-is-there-memory-allocation-and-time-difference-in-views-and-view/58149)

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**Author:** [@Shuhua](https://discourse.julialang.org/u/Shuhua)\
**Replies:** 9\
**Last updated:** [March 29, 2021, 8:07am UTC](https://discourse.julialang.org/t/why-is-there-memory-allocation-and-time-difference-in-views-and-view/58149 "2021-03-29T08:07:36Z")

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Julia Version 1.5.3 julia\> f(a, b, c) = a + b - c; julia\> X = randn(1000, 5); julia\> y = zeros(1000); # feed the last three columns of \`X\` into \`f\` and write the result into \`y\` julia\> @btime $y .= f((view($X, :, j)…

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## [Julia version/CUDA compatibility with Quadro K4100 compute capbility of 3](https://discourse.julialang.org/t/julia-version-cuda-compatibility-with-quadro-k4100-compute-capbility-of-3/58053)

<div class="topic-metadata">

**Author:** [@wizebt](https://discourse.julialang.org/u/wizebt)\
**Replies:** 1\
**Last updated:** [March 29, 2021, 5:49am UTC](https://discourse.julialang.org/t/julia-version-cuda-compatibility-with-quadro-k4100-compute-capbility-of-3/58053 "2021-03-29T05:49:16Z")

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Hi, I’m really struggling to find a compatible combination of versions: nVidia TK, Julia, CUDA.jl to execute a simple linear shift and add (see fct below) to efficiently run on my old Quadro K4100m GPU with compute capa…

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## [Map while preserving container type](https://discourse.julialang.org/t/map-while-preserving-container-type/58129)

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**Author:** [@jzr](https://discourse.julialang.org/u/jzr)\
**Replies:** 5\
**Last updated:** [March 29, 2021, 4:39am UTC](https://discourse.julialang.org/t/map-while-preserving-container-type/58129 "2021-03-29T04:39:37Z")

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I thought map was supposed to preserve the type of the container but both map and broadcast produce Arrays here. Why does this happen? What is the recommended way to apply a function to each element of a container while …

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## [Having edit(m::Module) open package directory instead of file where module is defined](https://discourse.julialang.org/t/having-edit-m-module-open-package-directory-instead-of-file-where-module-is-defined/58124)

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**Author:** [@airpmb](https://discourse.julialang.org/u/airpmb)\
**Replies:** 1\
**Last updated:** [March 28, 2021, 10:48pm UTC](https://discourse.julialang.org/t/having-edit-m-module-open-package-directory-instead-of-file-where-module-is-defined/58124 "2021-03-28T22:48:07Z")

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This line seems to do the trick: edit(m::Module) = edit(abspath(joinpath(pathof(m), "..", ".."))) # opens /Users/patrick/.julia/packages/AbstractPlotting/gE7AT/: edit(AbstractPlotting) … but I have a suspicion that w…

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## [Unsupported architecture 'aarch64' for macOS when adding Plots on Arm64 Linux](https://discourse.julialang.org/t/unsupported-architecture-aarch64-for-macos-when-adding-plots-on-arm64-linux/58134)

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**Author:** [@MikeHutch](https://discourse.julialang.org/u/MikeHutch)\
**Replies:** 4\
**Last updated:** [March 28, 2021, 10:20pm UTC](https://discourse.julialang.org/t/unsupported-architecture-aarch64-for-macos-when-adding-plots-on-arm64-linux/58134 "2021-03-28T22:20:48Z")

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I’ve build Julia 1.6.0 on my Raspberry Pi running 64bit Gentoo Linux. Everything appeared to be working fine until I tried to add Plots when I get an Unsupported architecture error, see below: import Pkg; Pkg.add("Plot…

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## [Avoid allocation of small arrays in median, extrema, etc](https://discourse.julialang.org/t/avoid-allocation-of-small-arrays-in-median-extrema-etc/58075)

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**Author:** [@weymouth](https://discourse.julialang.org/u/weymouth)\
**Replies:** 23\
**Last updated:** [March 28, 2021, 9:45pm UTC](https://discourse.julialang.org/t/avoid-allocation-of-small-arrays-in-median-extrema-etc/58075 "2021-03-28T21:45:48Z")

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I have a performance critical call to set bounds on a number. This code works like magic, but I want to know why it doesn’t need to allocate julia\> @benchmark clamp(v\[1\],extrema((v\[2\],v\[3\],v\[4\]))...) setup=(v=rand(4)) B…

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## [Constructor of parametric types](https://discourse.julialang.org/t/constructor-of-parametric-types/58136)

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**Author:** [@linwaytin](https://discourse.julialang.org/u/linwaytin)\
**Replies:** 6\
**Last updated:** [March 28, 2021, 9:31pm UTC](https://discourse.julialang.org/t/constructor-of-parametric-types/58136 "2021-03-28T21:31:03Z")

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I have the following two types. The second one is based on the first one. struct RankOneMatrix{T} \<: AbstractMatrix{T} v::AbstractVector{T} w::AbstractVector{T} end function Base.size(A::RankOneMatrix) retu…

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## [Alternate argument types](https://discourse.julialang.org/t/alternate-argument-types/58114)

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**Author:** [@gustaphe](https://discourse.julialang.org/u/gustaphe)\
**Replies:** 3\
**Last updated:** [March 28, 2021, 6:42pm UTC](https://discourse.julialang.org/t/alternate-argument-types/58114 "2021-03-28T18:42:08Z")

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Is there a macro or something that makes defining functions like this easier, where one or more of the arguments is of a given type? struct MyType \<: Number x::Float64 end f(a::MyType, b::MyType, c::MyType) = ... f…

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## [Drazin inverse/group inverse in Julia?](https://discourse.julialang.org/t/drazin-inverse-group-inverse-in-julia/58132)

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**Author:** [@Olof\_Salberger](https://discourse.julialang.org/u/Olof_Salberger)\
**Replies:** 0\
**Last updated:** [March 28, 2021, 7:19pm UTC](https://discourse.julialang.org/t/drazin-inverse-group-inverse-in-julia/58132 "2021-03-28T19:19:34Z")

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Is there an implementation of the Drazin inverse (aka group inverse) in Julia somewhere? It’s basically the unique pseudoinverse of a matrix x that commutes with x, if we slightly weaken the notion of pseudoinverse to hi…

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## [Any applications of Julia in Official Statistics?](https://discourse.julialang.org/t/any-applications-of-julia-in-official-statistics/58123)

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**Author:** [@sbacelar](https://discourse.julialang.org/u/sbacelar)\
**Replies:** 1\
**Last updated:** [March 28, 2021, 5:49pm UTC](https://discourse.julialang.org/t/any-applications-of-julia-in-official-statistics/58123 "2021-03-28T17:49:23Z")

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I tried to find something without success. There is a site with many applications in official statistics but mainly in R, Python and Java: awesome-official-statistics-software

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## [Instantiation of a subtype of an abstract type](https://discourse.julialang.org/t/instantiation-of-a-subtype-of-an-abstract-type/58126)

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**Author:** [@linwaytin](https://discourse.julialang.org/u/linwaytin)\
**Replies:** 2\
**Last updated:** [March 28, 2021, 6:16pm UTC](https://discourse.julialang.org/t/instantiation-of-a-subtype-of-an-abstract-type/58126 "2021-03-28T18:16:27Z")

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I’m following the MIT class “Introduction to Computational Thinking”, and have some trouble with the recent homework. (The class is amazing by the way. Any applied math course should be taught in this way IMO.) A struct…

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## [Passing complex struct to C function results in segfault](https://discourse.julialang.org/t/passing-complex-struct-to-c-function-results-in-segfault/58100)

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**Author:** [@oekenta](https://discourse.julialang.org/u/oekenta)\
**Replies:** 3\
**Last updated:** [March 28, 2021, 5:50pm UTC](https://discourse.julialang.org/t/passing-complex-struct-to-c-function-results-in-segfault/58100 "2021-03-28T17:50:32Z")

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I’m trying to interface with a C API for solving linear systems but I keep running into segfault errors. The algorithm uses a somewhat complex C structure, called LUSOLrec, to keep track of all the relevant data. \_LUSOL…

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## [JuliaInXL installation error while building](https://discourse.julialang.org/t/juliainxl-installation-error-while-building/41137)

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**Author:** [@frankhuettner](https://discourse.julialang.org/u/frankhuettner)\
**Replies:** 4\
**Last updated:** [March 28, 2021, 5:46pm UTC](https://discourse.julialang.org/t/juliainxl-installation-error-while-building/41137 "2021-03-28T17:46:49Z")

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Thank you for this wonderful language and the great support. I’d like to try JuliaInXL but during installation I receive the following error (Julia Pro 1.4.2., Windows 10, Office 365): What can I do?

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## [Unable to Install JuliaInXL package](https://discourse.julialang.org/t/unable-to-install-juliainxl-package/58125)

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**Author:** [@ajayreddy10](https://discourse.julialang.org/u/ajayreddy10)\
**Replies:** 0\
**Last updated:** [March 28, 2021, 5:33pm UTC](https://discourse.julialang.org/t/unable-to-install-juliainxl-package/58125 "2021-03-28T17:33:45Z")

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When I’m trying to install JuliaInXL package using JuliaPro it pops up with this error. Can anyone help me with this julia\> Pkg.add(“JuliaInXL”) Updating registry at C:\\Users\\ajay\\.julia\\registries\\JuliaComputingRegist…

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## [After upgrading to 1.6 adding any package results in (non-breaking) MethodError](https://discourse.julialang.org/t/after-upgrading-to-1-6-adding-any-package-results-in-non-breaking-methoderror/58119)

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**Author:** [@jonasjonker](https://discourse.julialang.org/u/jonasjonker)\
**Replies:** 0\
**Last updated:** [March 28, 2021, 3:07pm UTC](https://discourse.julialang.org/t/after-upgrading-to-1-6-adding-any-package-results-in-non-breaking-methoderror/58119 "2021-03-28T15:07:12Z")

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I upgraded to 1.6, and from that moment on I got the following error when adding a package. However, the package just seems to be installed, and works fine. ERROR: MethodError: Cannot \`convert\` an object of type Noth…

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## [Performance of norm function](https://discourse.julialang.org/t/performance-of-norm-function/14709)

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**Author:** [@tk3369](https://discourse.julialang.org/u/tk3369)\
**Replies:** 21\
**Last updated:** [March 28, 2021, 1:15pm UTC](https://discourse.julialang.org/t/performance-of-norm-function/14709 "2021-03-28T13:15:49Z")

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Custom for-loop seems 3x faster than LinearAlgebra’s norm… julia\> using LinearAlgebra, BenchmarkTools julia\> A = rand(5,5); julia\> function foo1(A) x = zero(eltype(A)) for v in A x += v \*…

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## [Horizontal y label with Plots.jl](https://discourse.julialang.org/t/horizontal-y-label-with-plots-jl/9967)

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**Author:** [@yha](https://discourse.julialang.org/u/yha)\
**Replies:** 4\
**Last updated:** [June 15, 2020, 3:36pm UTC](https://discourse.julialang.org/t/horizontal-y-label-with-plots-jl/9967 "2020-06-15T15:36:58Z")

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Is there any way to make the y axis label horizontal in Plots.jl (with pyplot backend)? Thanks

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## [Scatterplot with subplots for points](https://discourse.julialang.org/t/scatterplot-with-subplots-for-points/58097)

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**Author:** [@jzr](https://discourse.julialang.org/u/jzr)\
**Replies:** 3\
**Last updated:** [March 28, 2021, 2:47am UTC](https://discourse.julialang.org/t/scatterplot-with-subplots-for-points/58097 "2021-03-28T02:47:50Z")

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I have several (x,y) locations, each of which has an array of values: n observations at each (x,y) location. I want to make a scatterplot of the (x,y) pairs, but instead of a circle at each location, I want a little den…

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## [Use band-storage jacobian with CVODE\_BDF in OrdinaryDiffEq](https://discourse.julialang.org/t/use-band-storage-jacobian-with-cvode-bdf-in-ordinarydiffeq/58068)

<div class="topic-metadata">

**Author:** [@Nicholaswogan](https://discourse.julialang.org/u/Nicholaswogan)\
**Replies:** 4\
**Last updated:** [March 28, 2021, 2:07am UTC](https://discourse.julialang.org/t/use-band-storage-jacobian-with-cvode-bdf-in-ordinarydiffeq/58068 "2021-03-28T02:07:21Z")

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I am trying to solve a large system of ODEs. The jacobian of these ODEs is a band matrix. Is it possible to feed the CVODE\_BDF algorithm, from Sundials.jl, a function for the jacobian which returns the jacobian in band s…

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## [Performance regression with SAs as parameters in DiffEqs on Julia 1.6](https://discourse.julialang.org/t/performance-regression-with-sas-as-parameters-in-diffeqs-on-julia-1-6/58103)

<div class="topic-metadata">

**Author:** [@dcabecinhas](https://discourse.julialang.org/u/dcabecinhas)\
**Replies:** 0\
**Last updated:** [March 28, 2021, 1:32am UTC](https://discourse.julialang.org/t/performance-regression-with-sas-as-parameters-in-diffeqs-on-julia-1-6/58103 "2021-03-28T01:32:33Z")

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Hi all, I have some code where I pass parameters to ODE problems and it had some performance regressions with Julia 1.6. I distilled the code to highlight what seems to me to be at the root of the problem - passing Sta…

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## [Convex.jl set some configurations e.g. maximum iteration number, etc](https://discourse.julialang.org/t/convex-jl-set-some-configurations-e-g-maximum-iteration-number-etc/57724)

<div class="topic-metadata">

**Author:** [@iHany](https://discourse.julialang.org/u/iHany)\
**Replies:** 3\
**Last updated:** [March 27, 2021, 11:58pm UTC](https://discourse.julialang.org/t/convex-jl-set-some-configurations-e-g-maximum-iteration-number-etc/57724 "2021-03-27T23:58:56Z")

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I would like to change some configurations of Convex.jl optimiser. I took a look at the documentation but I didn’t understand how to do it. Can anybody help me? Note that I’m mostly using Mosek.

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## [Reading Parquet file from raw bytes?](https://discourse.julialang.org/t/reading-parquet-file-from-raw-bytes/58099)

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**Author:** [@calebwin](https://discourse.julialang.org/u/calebwin)\
**Replies:** 0\
**Last updated:** [March 27, 2021, 11:49pm UTC](https://discourse.julialang.org/t/reading-parquet-file-from-raw-bytes/58099 "2021-03-27T23:49:41Z")

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I’m downloading a Parquet file over network using AWSS3.jl. Is there any way of parsing raw bytes stored in memory as Parquet?

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## [ControlSystems -- transfer functions with delay?](https://discourse.julialang.org/t/controlsystems-transfer-functions-with-delay/58003)

<div class="topic-metadata">

**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 12\
**Last updated:** [March 27, 2021, 9:24pm UTC](https://discourse.julialang.org/t/controlsystems-transfer-functions-with-delay/58003 "2021-03-27T21:24:24Z")

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From the documentation: ControlSystems.tf — Function. sys = tf(num, den, Ts=0), sys = tf(gain, Ts=0) → Is it possible to define a time delay for functions tf and zpk? I’m trying to “sell” Julia to a friend, and he…

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## [V1.6 Package manager issue](https://discourse.julialang.org/t/v1-6-package-manager-issue/58054)

<div class="topic-metadata">

**Author:** [@monty](https://discourse.julialang.org/u/monty)\
**Replies:** 22\
**Last updated:** [March 27, 2021, 9:08pm UTC](https://discourse.julialang.org/t/v1-6-package-manager-issue/58054 "2021-03-27T21:08:40Z")

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The new version v1.6 creates strange problems with my packages which I can’t fix. For example: (@v1.6) pkg\> st JLD2 Status \`~/.julia/environments/v1.6/Project.toml\` \[033835bb\] JLD2 v0.3.3 (@v1.6) pkg\> up ERROR…

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## [A function like copyto! that acts recursively as deepcopy](https://discourse.julialang.org/t/a-function-like-copyto-that-acts-recursively-as-deepcopy/58027)

<div class="topic-metadata">

**Author:** [@kellertuer](https://discourse.julialang.org/u/kellertuer)\
**Replies:** 12\
**Last updated:** [March 27, 2021, 6:46pm UTC](https://discourse.julialang.org/t/a-function-like-copyto-that-acts-recursively-as-deepcopy/58027 "2021-03-27T18:46:00Z")

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Recently I stumbled upon a case where I for example have an array of arrays (a) and a second memory already allocated (b) – this might also be deeper nested than in the following example. a = \[\[1\],\[2\],\[3\]\] b = similar.(…

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## [Cairo fails on 1.6 to install](https://discourse.julialang.org/t/cairo-fails-on-1-6-to-install/58086)

<div class="topic-metadata">

**Author:** [@monty](https://discourse.julialang.org/u/monty)\
**Replies:** 0\
**Last updated:** [March 27, 2021, 5:59pm UTC](https://discourse.julialang.org/t/cairo-fails-on-1-6-to-install/58086 "2021-03-27T17:59:48Z")

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julia\> import Cairo \[ Info: Precompiling Cairo \[159f3aea-2a34-519c-b102-8c37f9878175\] ERROR: LoadError: LoadError: InitError: could not load library "/Users/vvv/.julia/artifacts/14819d58d81af1286ea71ca9ab144f64bb41f625/l…

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