# General Usage

**URL:** https://discourse.julialang.org/c/usage/6.md?page=672

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

**Page:** 673

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## [Handling "cyclical" dependencies upon new release?](https://discourse.julialang.org/t/handling-cyclical-dependencies-upon-new-release/50910)

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**Author:** [@tpoisot](https://discourse.julialang.org/u/tpoisot)\
**Replies:** 1\
**Last updated:** [November 29, 2020, 2:40am UTC](https://discourse.julialang.org/t/handling-cyclical-dependencies-upon-new-release/50910 "2020-11-29T02:40:13Z")

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I have a package (A) that is in its 0.3 versions, and I am about to update it to 0.4. To generate the documentation, I use two other packages (B, C) that depend on A. For the moment, I cannot build the documentation of A …

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## [Does an Artifact download always need to be a tarball/zipped file?](https://discourse.julialang.org/t/does-an-artifact-download-always-need-to-be-a-tarball-zipped-file/33964)

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**Author:** [@CiaranOMara](https://discourse.julialang.org/u/CiaranOMara)\
**Replies:** 4\
**Last updated:** [November 28, 2020, 8:24pm UTC](https://discourse.julialang.org/t/does-an-artifact-download-always-need-to-be-a-tarball-zipped-file/33964 "2020-11-28T20:24:17Z")

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I was hoping to bind an unzipped file as a download-artifact. However, the download\_artifact function always seems to attempt to unpack/unzip the downloaded file. How are other people handling/binding plain unzipped fil…

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## [Permutation of elements in array + composition of functions resulting into an extremely inefficient runtime?](https://discourse.julialang.org/t/permutation-of-elements-in-array-composition-of-functions-resulting-into-an-extremely-inefficient-runtime/48047)

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**Author:** [@GuidoDipietro](https://discourse.julialang.org/u/GuidoDipietro)\
**Replies:** 6\
**Last updated:** [November 28, 2020, 7:50pm UTC](https://discourse.julialang.org/t/permutation-of-elements-in-array-composition-of-functions-resulting-into-an-extremely-inefficient-runtime/48047 "2020-11-28T19:50:22Z")

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Hey there. I have started using Julia today or yesterday, and there is something happening here that is driving me a little bit crazy. I wanted to model a group of permutations (specifically, the permutation group of a …

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## [Trying to add Gaston.jl, missing Gnuplot for some reason](https://discourse.julialang.org/t/trying-to-add-gaston-jl-missing-gnuplot-for-some-reason/50888)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 10\
**Last updated:** [November 28, 2020, 6:20pm UTC](https://discourse.julialang.org/t/trying-to-add-gaston-jl-missing-gnuplot-for-some-reason/50888 "2020-11-28T18:20:13Z")

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When I test Gaston.jl, I’m told that Gnuplots is not available on the system. How do I add this? ┌ Warning: Gnuplot is not available on this system. Gaston will be unable to produce any plots. └ @ Gaston C:\\Users\\Brett…

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## [Call Julia function with keywords from C++](https://discourse.julialang.org/t/call-julia-function-with-keywords-from-c/20981)

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**Author:** [@Ronis\_BR](https://discourse.julialang.org/u/Ronis_BR)\
**Replies:** 3\
**Last updated:** [November 28, 2020, 6:03pm UTC](https://discourse.julialang.org/t/call-julia-function-with-keywords-from-c/20981 "2020-11-28T18:03:03Z")

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Hi guys! Let’s say I have Julia function: function teste(a::Int,b::Int; c = 1.0, d = 1.0, e = 1.0) return (a+b)^(c+d+e) end How can I call it from C++ modifying the keyword d?

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## [Now() - Date(2020) errors](https://discourse.julialang.org/t/now-date-2020-errors/50890)

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**Author:** [@sambitdash](https://discourse.julialang.org/u/sambitdash)\
**Replies:** 10\
**Last updated:** [November 28, 2020, 5:54pm UTC](https://discourse.julialang.org/t/now-date-2020-errors/50890 "2020-11-28T17:54:39Z")

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Hi All, I am seeing the following behavior with Julia 1.5.2 with Win64. julia\> now() - Date(2020) MethodError: no method matching -(::DateTime, ::Date) Closest candidates are: -(::DateTime, !Matched::Month) at D:\\bui…

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## [What are those artifacts?](https://discourse.julialang.org/t/what-are-those-artifacts/50893)

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**Author:** [@CodeLenz](https://discourse.julialang.org/u/CodeLenz)\
**Replies:** 2\
**Last updated:** [November 28, 2020, 1:09pm UTC](https://discourse.julialang.org/t/what-are-those-artifacts/50893 "2020-11-28T13:09:24Z")

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Hi There are a lot of artifacts like Xorg\_xcb\_\* being installed and updated when I do \]update. How can I learn more about these? Is there some reference about its need and adoption? Thanks in advance!

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## [Constant time Gaussian and Bilateral filter](https://discourse.julialang.org/t/constant-time-gaussian-and-bilateral-filter/50867)

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**Author:** [@Geoffrey](https://discourse.julialang.org/u/Geoffrey)\
**Replies:** 5\
**Last updated:** [November 28, 2020, 12:47pm UTC](https://discourse.julialang.org/t/constant-time-gaussian-and-bilateral-filter/50867 "2020-11-28T12:47:47Z")

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Hi, I’m still learning the julia language and to do so I try to implement different published algorithms that I found useful for my work (I’m a biologist and I do a lot of image analysis). So I have an implementation of…

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## [ParameterizedFunctions for setting up systems of ODEs](https://discourse.julialang.org/t/parameterizedfunctions-for-setting-up-systems-of-odes/50849)

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**Author:** [@Peter-Jolly](https://discourse.julialang.org/u/Peter-Jolly)\
**Replies:** 11\
**Last updated:** [November 28, 2020, 7:43am UTC](https://discourse.julialang.org/t/parameterizedfunctions-for-setting-up-systems-of-odes/50849 "2020-11-28T07:43:20Z")

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Hi, I am trying out an example to set up a system of ODE’s for solution using the ParameterizedFunctions package - looks quite useful. I keep getting an error and could do with some help. It seems the set of the method …

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## [Change default JULIA Path Manually in Ubuntu](https://discourse.julialang.org/t/change-default-julia-path-manually-in-ubuntu/50842)

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**Author:** [@clement](https://discourse.julialang.org/u/clement)\
**Replies:** 20\
**Last updated:** [November 28, 2020, 7:03am UTC](https://discourse.julialang.org/t/change-default-julia-path-manually-in-ubuntu/50842 "2020-11-28T07:03:45Z")

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I have managed to locally install a latest Julia (version 1.5.2) locally on an Ubuntu SuperComputer into a folder I created called Julia\_folder . I am able to use Julia within this folder. But my challenge is the system …

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## [VSC extension is showing "micro hangings" (on Windows)](https://discourse.julialang.org/t/vsc-extension-is-showing-micro-hangings-on-windows/50844)

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**Author:** [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Replies:** 0\
**Last updated:** [November 27, 2020, 1:01am UTC](https://discourse.julialang.org/t/vsc-extension-is-showing-micro-hangings-on-windows/50844 "2020-11-27T01:01:10Z")

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I am noticing that VSC randomly hangs for nearly a second and then continues. When that happens the task manager shows very high core activity (\> 50 %). Only me?

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## [JLD2 Type Reconstruction: Getting an Instance for an arbitrary Type](https://discourse.julialang.org/t/jld2-type-reconstruction-getting-an-instance-for-an-arbitrary-type/50850)

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**Author:** [@JonasIsensee](https://discourse.julialang.org/u/JonasIsensee)\
**Replies:** 2\
**Last updated:** [November 27, 2020, 3:37pm UTC](https://discourse.julialang.org/t/jld2-type-reconstruction-getting-an-instance-for-an-arbitrary-type/50850 "2020-11-27T15:37:31Z")

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Hi all, I recently tagged the v0.3.0 release for JLD2 that changed the internals to allow for defining custom serialization. Annoyingly I introduced a bug in the process. Previously type instantiation was done within…

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## ['using Plots' takes 20 seconds or more](https://discourse.julialang.org/t/using-plots-takes-20-seconds-or-more/7061)

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**Author:** [@airpmb](https://discourse.julialang.org/u/airpmb)\
**Replies:** 30\
**Last updated:** [November 27, 2020, 12:17pm UTC](https://discourse.julialang.org/t/using-plots-takes-20-seconds-or-more/7061 "2020-11-27T12:17:39Z")

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I’ve read that calls to using Plots can sometimes be slow but I wonder if as slow as I’m seeing is normal. On 3 trials after starting Julia from the command line I @timed this taking between 35 and 40 seconds. After som…

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## [How to replace multiple values in an large array with the occurrence of the value?](https://discourse.julialang.org/t/how-to-replace-multiple-values-in-an-large-array-with-the-occurrence-of-the-value/50741)

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**Author:** [@Bjorn\_De](https://discourse.julialang.org/u/Bjorn_De)\
**Replies:** 10\
**Last updated:** [November 27, 2020, 11:07am UTC](https://discourse.julialang.org/t/how-to-replace-multiple-values-in-an-large-array-with-the-occurrence-of-the-value/50741 "2020-11-27T11:07:27Z")

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Hi! I have an array and I want to create a new array (or replace the values) with the occurrences of the values from the input array. For example: using StatsBase blobs 10×10 Array{Int64,2}: 1 1 0 2 0 2 0 2 0…

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## [How to make a particular NTuple based Type concrete](https://discourse.julialang.org/t/how-to-make-a-particular-ntuple-based-type-concrete/50846)

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**Author:** [@malacroi](https://discourse.julialang.org/u/malacroi)\
**Replies:** 3\
**Last updated:** [November 27, 2020, 6:27am UTC](https://discourse.julialang.org/t/how-to-make-a-particular-ntuple-based-type-concrete/50846 "2020-11-27T06:27:47Z")

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I have a struct representing the remainders of an integer with respect to several moduli. All of the moduli fit into Int64 except for 2^64, so every modulus is either an Int64 or Type{Int64}. struct LooseGoose{N} …

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## [Unable to Download Jupyter Notebook](https://discourse.julialang.org/t/unable-to-download-jupyter-notebook/50845)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 1\
**Last updated:** [November 27, 2020, 3:22am UTC](https://discourse.julialang.org/t/unable-to-download-jupyter-notebook/50845 "2020-11-27T03:22:03Z")

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I posted before about not being able to export a Jupyter notebook, to another format, such as pdf, and getting an error about nbconvert not working right. Apparently, when I try to download a notebook from Jupyter noteb…

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## [Generate package code: string processing or metaprogramming?](https://discourse.julialang.org/t/generate-package-code-string-processing-or-metaprogramming/50778)

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**Author:** [@serenity4](https://discourse.julialang.org/u/serenity4)\
**Replies:** 4\
**Last updated:** [November 26, 2020, 8:08pm UTC](https://discourse.julialang.org/t/generate-package-code-string-processing-or-metaprogramming/50778 "2020-11-26T20:08:17Z")

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Hi, I am wrapping a low-level API generated with Clang.jl, and generate source code (with some string processing) to programmatically create the wrapper code (around 30k lines of Julia code, it’s a big library). I am wo…

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## [Should I still be using JSON.jl?](https://discourse.julialang.org/t/should-i-still-be-using-json-jl/50809)

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**Author:** [@DataPsycho](https://discourse.julialang.org/u/DataPsycho)\
**Replies:** 2\
**Last updated:** [November 26, 2020, 2:38pm UTC](https://discourse.julialang.org/t/should-i-still-be-using-json-jl/50809 "2020-11-26T14:38:49Z")

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Hi, I was exploring the HTTP.jl example docs (Section: Interfacing with RESTful JSON APIs) and and can see for JSON data example everything is written with JSON.jl or JSON2.jl. But from one of the webinar by Julia Compu…

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## [Loop slows things down drastically](https://discourse.julialang.org/t/loop-slows-things-down-drastically/50761)

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**Author:** [@mlhetland](https://discourse.julialang.org/u/mlhetland)\
**Replies:** 5\
**Last updated:** [November 26, 2020, 1:14pm UTC](https://discourse.julialang.org/t/loop-slows-things-down-drastically/50761 "2020-11-26T13:14:39Z")

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OK, this’ll be a bit vague, as I’m working on some unpublished code, but maybe someone can still spot what’s going on… I have a testset that looks something like thus: @testset begin x = Something() # various f…

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## [I can't get to the "end of inflation" with DifferentialEquations.jl](https://discourse.julialang.org/t/i-cant-get-to-the-end-of-inflation-with-differentialequations-jl/50697)

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**Author:** [@MrSantiagoPrado](https://discourse.julialang.org/u/MrSantiagoPrado)\
**Replies:** 20\
**Last updated:** [November 26, 2020, 12:19pm UTC](https://discourse.julialang.org/t/i-cant-get-to-the-end-of-inflation-with-differentialequations-jl/50697 "2020-11-26T12:19:00Z")

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Hello all, I’ve been struggling to get the full solution to a set of ODE’s that describe an inflationary cosmology, where the equations, the value of the constants and the initial values are given below on the code. In t…

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## [Julia DifferentialEquations for state-to-state binary mixture kinetics](https://discourse.julialang.org/t/julia-differentialequations-for-state-to-state-binary-mixture-kinetics/50807)

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**Author:** [@lkampoli](https://discourse.julialang.org/u/lkampoli)\
**Replies:** 1\
**Last updated:** [November 26, 2020, 10:41am UTC](https://discourse.julialang.org/t/julia-differentialequations-for-state-to-state-binary-mixture-kinetics/50807 "2020-11-26T10:41:29Z")

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Hello, I’m quite new to Julia and I’m considering the following problem. I’d like to solve the (possible stiff) ODE system which describes the relaxation of a flow behind a shock wave according to a state-to-state approa…

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## [JLD load error for Dict](https://discourse.julialang.org/t/jld-load-error-for-dict/50710)

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**Author:** [@katdeane](https://discourse.julialang.org/u/katdeane)\
**Replies:** 10\
**Last updated:** [November 26, 2020, 8:23am UTC](https://discourse.julialang.org/t/jld-load-error-for-dict/50710 "2020-11-26T08:23:33Z")

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I am using dictionaries to store matrices of data under a series of tags such as the following: "GroupIdentifier"=\>Dict{Any,Any}("SubjectNumber"=\>Dict{Any,Any}("StimulusType"=\>Dict{Any,Any}("RecordingPlace"=\>(\[dat1\],\[da…

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## [Is There a Way to Find Symbolic Roots?](https://discourse.julialang.org/t/is-there-a-way-to-find-symbolic-roots/50772)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 1\
**Last updated:** [November 25, 2020, 10:38pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-find-symbolic-roots/50772 "2020-11-25T22:38:33Z")

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I’m able to find a floating point approximation of the a second derivative, but I know the actual answer is log(a). Is there a way to find this symbolically? using ModelingToolkit using Roots p(t,a)=1/(1+a\*exp((-t))) …

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## [BinaryBuilder cross-coompilation env needs an additional library](https://discourse.julialang.org/t/binarybuilder-cross-coompilation-env-needs-an-additional-library/50505)

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**Author:** [@Mikhail\_Kagalenko](https://discourse.julialang.org/u/Mikhail_Kagalenko)\
**Replies:** 12\
**Last updated:** [November 25, 2020, 4:28pm UTC](https://discourse.julialang.org/t/binarybuilder-cross-coompilation-env-needs-an-additional-library/50505 "2020-11-25T16:28:46Z")

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I am trying to include a C++ library with julia package. After BinaryBuilder’s wizard drops me into cross-compilation environment, the configure script that I sun within the source directory informs me that I need an add…

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## [Windows file path string (slash direction, best way to copy/paste)](https://discourse.julialang.org/t/windows-file-path-string-slash-direction-best-way-to-copy-paste/29204)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 5\
**Last updated:** [November 25, 2020, 1:49pm UTC](https://discourse.julialang.org/t/windows-file-path-string-slash-direction-best-way-to-copy-paste/29204 "2020-11-25T13:49:21Z")

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One of the most annoying things that I do on a daily basis (on my Windows 10 machine) is finding a path to a file that has some data that I want to bring into my program, right-clicking it, clicking ‘Properties’ and then…

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## [Mutation and recombination rate of DE algorithm in BlackBoxOptim](https://discourse.julialang.org/t/mutation-and-recombination-rate-of-de-algorithm-in-blackboxoptim/50726)

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**Author:** [@yusri-dh](https://discourse.julialang.org/u/yusri-dh)\
**Replies:** 2\
**Last updated:** [November 25, 2020, 1:45pm UTC](https://discourse.julialang.org/t/mutation-and-recombination-rate-of-de-algorithm-in-blackboxoptim/50726 "2020-11-25T13:45:43Z")

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Is there any way to know and change the mutation and recombination rate of the differential evolution algorithm in BlackBoxOptim?

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## [Plots: JuliaGraphics / Colors.jl removing the guess of colours](https://discourse.julialang.org/t/plots-juliagraphics-colors-jl-removing-the-guess-of-colours/50010)

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**Author:** [@JosephPollacco](https://discourse.julialang.org/u/JosephPollacco)\
**Replies:** 9\
**Last updated:** [November 25, 2020, 11:19am UTC](https://discourse.julialang.org/t/plots-juliagraphics-colors-jl-removing-the-guess-of-colours/50010 "2020-11-25T11:19:04Z")

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We are ever so grateful of having such a great variety of colour options in Plots which is great for publications. But the question is how can we get a preview of the colour before trying them out? Colours # This is t…

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## [Unpacking binary data into a Julia struct](https://discourse.julialang.org/t/unpacking-binary-data-into-a-julia-struct/32941)

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**Author:** [@tlnagy](https://discourse.julialang.org/u/tlnagy)\
**Replies:** 7\
**Last updated:** [November 25, 2020, 8:43am UTC](https://discourse.julialang.org/t/unpacking-binary-data-into-a-julia-struct/32941 "2020-11-25T08:43:17Z")

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I’m having a hard time finding an example in Julia v1.0+ for handling unpacking binary data into a Julia struct. Is there an easy way to do this? Say I have some custom struct Test and wanted to read some binary data fr…

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## [Debugging of julia modules lead to errors while evaluating not](https://discourse.julialang.org/t/debugging-of-julia-modules-lead-to-errors-while-evaluating-not/50036)

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**Author:** [@Volker](https://discourse.julialang.org/u/Volker)\
**Replies:** 7\
**Last updated:** [November 25, 2020, 8:10am UTC](https://discourse.julialang.org/t/debugging-of-julia-modules-lead-to-errors-while-evaluating-not/50036 "2020-11-25T08:10:19Z")

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Hi, I often would like to debug the code of some julia modules i.e. DiffEqFlux or Flux to better understand what is going on, but some how I get error messages during debugging, which I don´t get when I just evaluate th…

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## [3d Plots using Plots.jl](https://discourse.julialang.org/t/3d-plots-using-plots-jl/50723)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 1\
**Last updated:** [November 25, 2020, 4:23am UTC](https://discourse.julialang.org/t/3d-plots-using-plots-jl/50723 "2020-11-25T04:23:06Z")

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If I have a function using Plots f(x,c)=x^2+6x+(c/x) how do I make it into a 3d plot like a topographic map?

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