# General Usage

**URL:** https://discourse.julialang.org/c/usage/6.md?page=148

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**Page:** 149

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## [How to copy a Axis from fig1 to fig2 in makie?](https://discourse.julialang.org/t/how-to-copy-a-axis-from-fig1-to-fig2-in-makie/92716)

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**Author:** [@tiZ](https://discourse.julialang.org/u/tiZ)\
**Replies:** 4\
**Last updated:** [July 20, 2024, 11:24pm UTC](https://discourse.julialang.org/t/how-to-copy-a-axis-from-fig1-to-fig2-in-makie/92716 "2024-07-20T23:24:44Z")

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Hi, I plot a scatter plot in fig1 position \[1,1\], then a lines plot in fig2 position \[1,1\], any idea on how to copy the scatter from fig1\[1,1\] into fig2\[1,2\]? I do some try but failed: x,y = rand(10), rand(10) fig1, a…

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## [OrderedDict from OrderedCollections.jl](https://discourse.julialang.org/t/ordereddict-from-orderedcollections-jl/117283)

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**Author:** [@scottrsm](https://discourse.julialang.org/u/scottrsm)\
**Replies:** 4\
**Last updated:** [July 20, 2024, 10:38pm UTC](https://discourse.julialang.org/t/ordereddict-from-orderedcollections-jl/117283 "2024-07-20T22:38:11Z")

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I tried merging two OrderedDicts with merge (also with merge!). The resulting dictionary was of type OrderedDict but was not Ordered!!!

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## [Exodus.jl error in write from scratch example](https://discourse.julialang.org/t/exodus-jl-error-in-write-from-scratch-example/111696)

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**Author:** [@jman87](https://discourse.julialang.org/u/jman87)\
**Replies:** 11\
**Last updated:** [July 20, 2024, 6:15pm UTC](https://discourse.julialang.org/t/exodus-jl-error-in-write-from-scratch-example/111696 "2024-07-20T18:15:21Z")

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@Craig\_Hamel I just installed Exodus.jl on my M2 MacBook Air running Julia 1.10.2. When I try to run the " Write example from scratch" example shown here: GitHub - cmhamel/Exodus.jl: A julia interface for accessing th…

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## [Custom gradients for function. Resource for rrule and frule](https://discourse.julialang.org/t/custom-gradients-for-function-resource-for-rrule-and-frule/117154)

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**Author:** [@KapilKhanal](https://discourse.julialang.org/u/KapilKhanal)\
**Replies:** 18\
**Last updated:** [July 20, 2024, 4:37pm UTC](https://discourse.julialang.org/t/custom-gradients-for-function-resource-for-rrule-and-frule/117154 "2024-07-20T16:37:16Z")

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I am trying to create a custom gradients for a greens function whose term by term direct differentiation is not that accurate and we have a derivation of it’s derivatives and would like to use those. For the simple MWE e…

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## [How to make a struct that contains a reference to other memory?](https://discourse.julialang.org/t/how-to-make-a-struct-that-contains-a-reference-to-other-memory/117195)

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**Author:** [@AwesomeQuest](https://discourse.julialang.org/u/AwesomeQuest)\
**Replies:** 12\
**Last updated:** [July 20, 2024, 3:53pm UTC](https://discourse.julialang.org/t/how-to-make-a-struct-that-contains-a-reference-to-other-memory/117195 "2024-07-20T15:53:04Z")

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I have a vector of nodes, something like struct Node x::Float64 # more fields end nodes = Vector{Node}(undef, bignumber) And I have a vector of Elements that each contain some nodes struct Element numN…

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## [Why is there a difference between CWTs generated in python vs julia](https://discourse.julialang.org/t/why-is-there-a-difference-between-cwts-generated-in-python-vs-julia/117259)

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**Author:** [@bryaan](https://discourse.julialang.org/u/bryaan)\
**Replies:** 0\
**Last updated:** [July 20, 2024, 12:30am UTC](https://discourse.julialang.org/t/why-is-there-a-difference-between-cwts-generated-in-python-vs-julia/117259 "2024-07-20T00:30:41Z")

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pywt and ContinuousWavelets.jl give very different heatmap results for a cwt. What is the reason for this? In julia: In python:

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## [Some strange linking behavior in Julia](https://discourse.julialang.org/t/some-strange-linking-behavior-in-julia/117182)

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**Author:** [@dmitry-kabanov](https://discourse.julialang.org/u/dmitry-kabanov)\
**Replies:** 2\
**Last updated:** [July 19, 2024, 10:42am UTC](https://discourse.julialang.org/t/some-strange-linking-behavior-in-julia/117182 "2024-07-19T10:42:20Z")

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Hi, I have some code that embeds Julia and uses OrdinaryDiffEqs.jl. I am also having unit tests, which are organized in such what that the OrdinaryDiffEqs.jl package gets reloaded, while Julia is kept between tests, beca…

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## [Solving EnsembleProblem efficiently for large systems: memory issues](https://discourse.julialang.org/t/solving-ensembleproblem-efficiently-for-large-systems-memory-issues/116146)

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**Author:** [@johannesnauta](https://discourse.julialang.org/u/johannesnauta)\
**Replies:** 10\
**Last updated:** [July 19, 2024, 9:03am UTC](https://discourse.julialang.org/t/solving-ensembleproblem-efficiently-for-large-systems-memory-issues/116146 "2024-07-19T09:03:45Z")

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I apologize in advance for this length thread, but the problem setting is relatively complicated and this was the smallest MWE that I could think of, while still remaining clear. Problem setting I am encountering some i…

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## [Is multiple dispatch the best way to handle multiple possible combinations in a package?](https://discourse.julialang.org/t/is-multiple-dispatch-the-best-way-to-handle-multiple-possible-combinations-in-a-package/117215)

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**Author:** [@NikoBiele](https://discourse.julialang.org/u/NikoBiele)\
**Replies:** 2\
**Last updated:** [July 19, 2024, 8:39am UTC](https://discourse.julialang.org/t/is-multiple-dispatch-the-best-way-to-handle-multiple-possible-combinations-in-a-package/117215 "2024-07-19T08:39:01Z")

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Hi Julia people, I’m currently working on a major update for my package ‘RayTraceHeatTransfer.jl’. I want the updated package to contain the following features (many of which are new): 1D/2D/3D geometry (user can defi…

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## [Select columns from StructArray](https://discourse.julialang.org/t/select-columns-from-structarray/117214)

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**Author:** [@jar1](https://discourse.julialang.org/u/jar1)\
**Replies:** 2\
**Last updated:** [July 19, 2024, 6:46am UTC](https://discourse.julialang.org/t/select-columns-from-structarray/117214 "2024-07-19T06:46:31Z")

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How can I choose columns from a StructArray? julia\> StructArray(a=\[1,2\], b=\[10,20\], c=\[100, 200\])\[(:a,:b)\] ERROR: ArgumentError: invalid index: (:a, :b) of type Tuple{Symbol, Symbol}

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## [DifferentialEquations.jl Spring Mass Damper with variable force being applied](https://discourse.julialang.org/t/differentialequations-jl-spring-mass-damper-with-variable-force-being-applied/117209)

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**Author:** [@bryaan](https://discourse.julialang.org/u/bryaan)\
**Replies:** 1\
**Last updated:** [July 19, 2024, 4:10am UTC](https://discourse.julialang.org/t/differentialequations-jl-spring-mass-damper-with-variable-force-being-applied/117209 "2024-07-19T04:10:31Z")

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I am trying to do a simulation of a spring mass damper system where a variable force is constantly being applied at each integer time step. I want to see the mass’ position in a plot. This code seems to be a start but I…

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## [What are the advantages of using a notebook for development?](https://discourse.julialang.org/t/what-are-the-advantages-of-using-a-notebook-for-development/117043)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 13\
**Last updated:** [July 18, 2024, 8:28pm UTC](https://discourse.julialang.org/t/what-are-the-advantages-of-using-a-notebook-for-development/117043 "2024-07-18T20:28:12Z")

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I wander why so many people seem to prefer using a notebook, i.e. the Jupiter Notebook, to develop Julia code, and I am curious to understand which is the main advantage over using a more classical IDE approach (Atom/VsC…

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## [Struct docstring](https://discourse.julialang.org/t/struct-docstring/117196)

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**Author:** [@co1emi11er](https://discourse.julialang.org/u/co1emi11er)\
**Replies:** 0\
**Last updated:** [July 18, 2024, 6:59pm UTC](https://discourse.julialang.org/t/struct-docstring/117196 "2024-07-18T18:59:17Z")

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Hello, I have the following code (you don’t need to understand it, just know its a struct with a docstring as well as an inner constructor with a docstring): """ struct RectangularColumn \<: Column A rectangualr co…

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## [Simplest Sign type](https://discourse.julialang.org/t/simplest-sign-type/4254)

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**Author:** [@yakir12](https://discourse.julialang.org/u/yakir12)\
**Replies:** 14\
**Last updated:** [July 18, 2024, 5:48pm UTC](https://discourse.julialang.org/t/simplest-sign-type/4254 "2024-07-18T17:48:10Z")

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What would be the simplest/best way to encode sign, as in +1 or -1, as a type? Here’s what I can think of: A type with an Int field which I then set to either +1 or -1 when setting an instance of said type, and then m…

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## [Decimal2rational](https://discourse.julialang.org/t/decimal2rational/117147)

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**Author:** [@mefi](https://discourse.julialang.org/u/mefi)\
**Replies:** 7\
**Last updated:** [July 18, 2024, 8:42am UTC](https://discourse.julialang.org/t/decimal2rational/117147 "2024-07-18T08:42:29Z")

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Is there an easy way to convert a periodic decimal number into a fraction? As a mathematician I like not rationalize(0.85555555555)!! That really leaves a homemade algorithm that handles the periodic part separately? t…

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## [How to estimate many successive parameters of system of ODEs?](https://discourse.julialang.org/t/how-to-estimate-many-successive-parameters-of-system-of-odes/117144)

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**Author:** [@LSchueler](https://discourse.julialang.org/u/LSchueler)\
**Replies:** 3\
**Last updated:** [July 18, 2024, 7:40am UTC](https://discourse.julialang.org/t/how-to-estimate-many-successive-parameters-of-system-of-odes/117144 "2024-07-18T07:40:23Z")

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Hi, I have a system of ODEs for which I’d like to estimate its parameters by fitting it to observational data. The only “interesting” part of this problem is that the parameters vary on a daily basis. A naive approach …

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## [Correct way to archive older versions of your registered package?](https://discourse.julialang.org/t/correct-way-to-archive-older-versions-of-your-registered-package/117168)

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**Author:** [@K5Julien](https://discourse.julialang.org/u/K5Julien)\
**Replies:** 1\
**Last updated:** [July 18, 2024, 6:17am UTC](https://discourse.julialang.org/t/correct-way-to-archive-older-versions-of-your-registered-package/117168 "2024-07-18T06:17:29Z")

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Dear Julia Discourse community, I have several versions of my package (from v0.1.0 to v0.1.6). At the first versions, I did not use many tools (CompatHelper, CI, TagBot, Tests.jl, etc.). I was not aware of MoJuWo yet n…

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## [Making the review process more pleasant for new contributors](https://discourse.julialang.org/t/making-the-review-process-more-pleasant-for-new-contributors/102604)

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**Author:** [@adienes](https://discourse.julialang.org/u/adienes)\
**Replies:** 59\
**Last updated:** [July 18, 2024, 2:18am UTC](https://discourse.julialang.org/t/making-the-review-process-more-pleasant-for-new-contributors/102604 "2024-07-18T02:18:03Z")

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of course I understand there are resource constraints on reviewers, and ultimately there will always be a backlog. that being said, sometimes it feels like PRs that are “ready” for at least feedback, if not a merge, go…

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## [Is there an alternative of StringCases.jl that changes string cases?](https://discourse.julialang.org/t/is-there-an-alternative-of-stringcases-jl-that-changes-string-cases/40994)

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**Author:** [@singularitti](https://discourse.julialang.org/u/singularitti)\
**Replies:** 6\
**Last updated:** [July 18, 2024, 1:11am UTC](https://discourse.julialang.org/t/is-there-an-alternative-of-stringcases-jl-that-changes-string-cases/40994 "2024-07-18T01:11:44Z")

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I want to switch strings between camelCase, PascalCase, snake\_case, etc. I found one package StringCases.jl but it is old and seems to be unmaintained. Is there any alternative?

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## [Boolean open modes for \`open()\`](https://discourse.julialang.org/t/boolean-open-modes-for-open/117157)

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**Author:** [@ryofurue](https://discourse.julialang.org/u/ryofurue)\
**Replies:** 2\
**Last updated:** [July 18, 2024, 1:08am UTC](https://discourse.julialang.org/t/boolean-open-modes-for-open/117157 "2024-07-18T01:08:31Z")

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I’m trying to understand the keyword arguments write, truncate, . . . , of the open() function. I put a link to the documentation at the end of this message. Specifically, I want to know What it means if you specify w…

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## [Why are booleans printed as numbers?](https://discourse.julialang.org/t/why-are-booleans-printed-as-numbers/117164)

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**Author:** [@greatpet](https://discourse.julialang.org/u/greatpet)\
**Replies:** 4\
**Last updated:** [July 17, 2024, 10:21pm UTC](https://discourse.julialang.org/t/why-are-booleans-printed-as-numbers/117164 "2024-07-17T22:21:01Z")

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With Julia 1.10.4: julia\> \[("a", true), ("b", false)\] 2-element Vector{Tuple{String, Bool}}: ("a", 1) ("b", 0) Here true / false are confusingly printed as 1 / 0.

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## [Reading text data: \`readdlm\` is deprecated, so how CSV package is used?](https://discourse.julialang.org/t/reading-text-data-readdlm-is-deprecated-so-how-csv-package-is-used/116955)

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**Author:** [@ryofurue](https://discourse.julialang.org/u/ryofurue)\
**Replies:** 9\
**Last updated:** [July 17, 2024, 5:45pm UTC](https://discourse.julialang.org/t/reading-text-data-readdlm-is-deprecated-so-how-csv-package-is-used/116955 "2024-07-17T17:45:49Z")

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In the issue tracker of DelimitedFiles I found a comment readdlm is also effectively deprecated and the CSV package should be used about reading text data files. I’m trying to read a plain text file listing numbe…

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## [Googlesheet name](https://discourse.julialang.org/t/googlesheet-name/117146)

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**Author:** [@dgagnon](https://discourse.julialang.org/u/dgagnon)\
**Replies:** 2\
**Last updated:** [July 17, 2024, 4:35pm UTC](https://discourse.julialang.org/t/googlesheet-name/117146 "2024-07-17T16:35:08Z")

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Hello I can open a Googlesheet and get all sheet names inside with functionsheet\_names() with a GoogleSheetsClient and its id. However, I never found how to get the Spreadsheet name which is displayed in the browser. I…

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## [Julia and C++ paired code dataset](https://discourse.julialang.org/t/julia-and-c-paired-code-dataset/117150)

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**Author:** [@Arijit\_Bhattacharjee](https://discourse.julialang.org/u/Arijit_Bhattacharjee)\
**Replies:** 5\
**Last updated:** [July 17, 2024, 4:33pm UTC](https://discourse.julialang.org/t/julia-and-c-paired-code-dataset/117150 "2024-07-17T16:33:15Z")

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Is there any repo or resources where I can find a Julia and C++ paired dataset. I need a julia implementation and the same implementation in C++. Any guidance would be really helpful.

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## [Modify a Package, and load it](https://discourse.julialang.org/t/modify-a-package-and-load-it/117105)

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**Author:** [@gustave\_Robichon](https://discourse.julialang.org/u/gustave_Robichon)\
**Replies:** 5\
**Last updated:** [July 17, 2024, 1:50pm UTC](https://discourse.julialang.org/t/modify-a-package-and-load-it/117105 "2024-07-17T13:50:26Z")

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Hello :slight\_smile: I am using a SemiDefiniteProgram to solve a Quantum problem. I give to the SDP some constraints, and it makes a QR factorization which lasts a very long time, and then it makes some iterations. Duri…

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## [IOContext :compact when showing array](https://discourse.julialang.org/t/iocontext-compact-when-showing-array/108163)

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**Author:** [@goerz](https://discourse.julialang.org/u/goerz)\
**Replies:** 2\
**Last updated:** [July 17, 2024, 12:24pm UTC](https://discourse.julialang.org/t/iocontext-compact-when-showing-array/108163 "2024-07-17T12:24:57Z")

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The documentation of IOContext says :compact \[…\] is set when printing array elements. However, I don’t find this to be true: struct MyStruct v::String end function Base.show(io::IO, val::MyStruct) if haskey…

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## [Error using package in local environment](https://discourse.julialang.org/t/error-using-package-in-local-environment/91777)

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**Author:** [@mmv](https://discourse.julialang.org/u/mmv)\
**Replies:** 17\
**Last updated:** [July 17, 2024, 8:20am UTC](https://discourse.julialang.org/t/error-using-package-in-local-environment/91777 "2024-07-17T08:20:47Z")

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Hi! I am using the StringViews package which works fine in the normal REPL, but is not found when I get into the test environment, even though I included a statement using StringViews in the runtests.jl file, as well as…

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## [Memory usage of binaries from juliac compiler?](https://discourse.julialang.org/t/memory-usage-of-binaries-from-juliac-compiler/116918)

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**Author:** [@greatpet](https://discourse.julialang.org/u/greatpet)\
**Replies:** 3\
**Last updated:** [July 17, 2024, 8:19am UTC](https://discourse.julialang.org/t/memory-usage-of-binaries-from-juliac-compiler/116918 "2024-07-17T08:19:15Z")

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There has been a JuliaCon talk about generating small binaries with juliac: This brings down the binary size, but does it bring down the startup RAM usage? It’s currently more than 200 MB on Linux.

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## [Why are \`seed!\` and \`default\_rng\` not public?](https://discourse.julialang.org/t/why-are-seed-and-default-rng-not-public/117125)

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**Author:** [@GHTaarn](https://discourse.julialang.org/u/GHTaarn)\
**Replies:** 1\
**Last updated:** [July 17, 2024, 6:51am UTC](https://discourse.julialang.org/t/why-are-seed-and-default-rng-not-public/117125 "2024-07-17T06:51:29Z")

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julia\> VERSION v"1.11.0-rc1" julia\> using Random julia\> Base.ispublic(Random, :seed!), Base.ispublic(Random, :default\_rng) (false, false) Does this mean that one should avoid using these functions if the code should b…

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## [How to solve Equations with Variables on Both Sides](https://discourse.julialang.org/t/how-to-solve-equations-with-variables-on-both-sides/117121)

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**Author:** [@HamidrezaSafari](https://discourse.julialang.org/u/HamidrezaSafari)\
**Replies:** 1\
**Last updated:** [July 17, 2024, 6:47am UTC](https://discourse.julialang.org/t/how-to-solve-equations-with-variables-on-both-sides/117121 "2024-07-17T06:47:51Z")

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Polynomial equations like x^2-3x = 2 and x^2-3x \> 4

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