# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1667

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

**Page:** 1668

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## [Humble Bundle Including Julia Book](https://discourse.julialang.org/t/humble-bundle-including-julia-book/44434)

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**Author:** [@Ian\_Slagle](https://discourse.julialang.org/u/Ian_Slagle)\
**Replies:** 2\
**Last updated:** [August 6, 2020, 6:24pm UTC](https://discourse.julialang.org/t/humble-bundle-including-julia-book/44434 "2020-08-06T18:24:34Z")

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I don’t know if this fits this particular category exactly, but there is a Humble Bundle of books on programming languages, and one on Julia (The O’Reilly “Think Julia”) is in the $1 section.

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## [Using symbolic mathematics to find equations of motion](https://discourse.julialang.org/t/using-symbolic-mathematics-to-find-equations-of-motion/44442)

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**Author:** [@Bruno\_Mendes](https://discourse.julialang.org/u/Bruno_Mendes)\
**Replies:** 1\
**Last updated:** [August 6, 2020, 6:11pm UTC](https://discourse.julialang.org/t/using-symbolic-mathematics-to-find-equations-of-motion/44442 "2020-08-06T18:11:48Z")

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I am working with a reduced-order mathematical model for the motion of a offshore platform. The deduction of equations of motion requires a lot of symbolic computation as differentiation of time-dependent variables and …

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## [Deploying generated documents privately](https://discourse.julialang.org/t/deploying-generated-documents-privately/24038)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 7\
**Last updated:** [August 6, 2020, 5:52pm UTC](https://discourse.julialang.org/t/deploying-generated-documents-privately/24038 "2020-08-06T17:52:11Z")

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I am working on a project using Julia which will eventually be made public & open source. We are currently working using a private repo Gitlab, and are in the process of writing up docs — this helps coauthors and should …

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## [Reshape() still allocating memory in Julia 1.5.0](https://discourse.julialang.org/t/reshape-still-allocating-memory-in-julia-1-5-0/44437)

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**Author:** [@benwcs](https://discourse.julialang.org/u/benwcs)\
**Replies:** 2\
**Last updated:** [August 6, 2020, 5:49pm UTC](https://discourse.julialang.org/t/reshape-still-allocating-memory-in-julia-1-5-0/44437 "2020-08-06T17:49:55Z")

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It is great to see views no longer allocate memory in Julia 1.5.0! This we be very helpful for a project I am currenlty working on. However, it seems that calls to reshape still do, unless I use the @uviews macro supplie…

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## [How would I remove a column from a dataframe by distributing its values among existing columns?](https://discourse.julialang.org/t/how-would-i-remove-a-column-from-a-dataframe-by-distributing-its-values-among-existing-columns/44265)

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**Author:** [@Julia1](https://discourse.julialang.org/u/Julia1)\
**Replies:** 4\
**Last updated:** [August 6, 2020, 5:02pm UTC](https://discourse.julialang.org/t/how-would-i-remove-a-column-from-a-dataframe-by-distributing-its-values-among-existing-columns/44265 "2020-08-06T17:02:05Z")

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Hi how’s it going? I have a situation where I’m keeping counts of certain visits, and in some scenarios the person visits multiple places during one trip. However, I can’t have this as part of my data, and need it to be…

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## [Disjoint sets](https://discourse.julialang.org/t/disjoint-sets/44419)

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**Author:** [@omar](https://discourse.julialang.org/u/omar)\
**Replies:** 2\
**Last updated:** [August 6, 2020, 4:59pm UTC](https://discourse.julialang.org/t/disjoint-sets/44419 "2020-08-06T16:59:58Z")

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I tried using Disjoint sets but encountered an error “ERROR: LoadError: UndefVarError: IntDisjointSets not defined”. I’m using julia version 1.4.1 and my code was simply just: U = IntDisjointSets(10) println(U)

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## [FEM frameworks for simulations which couple diffusion and linear elasticity](https://discourse.julialang.org/t/fem-frameworks-for-simulations-which-couple-diffusion-and-linear-elasticity/44431)

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**Author:** [@feanor12](https://discourse.julialang.org/u/feanor12)\
**Replies:** 0\
**Last updated:** [August 6, 2020, 4:30pm UTC](https://discourse.julialang.org/t/fem-frameworks-for-simulations-which-couple-diffusion-and-linear-elasticity/44431 "2020-08-06T16:30:19Z")

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I want to simulate a cylinder symmetric 2d multi material structure to solve a reaction diffusion problem coupled with a linear elasticity. What FEM package would be most suited for a simulation like this? As the react…

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## [Managing larger project in Julia](https://discourse.julialang.org/t/managing-larger-project-in-julia/44413)

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**Author:** [@musman](https://discourse.julialang.org/u/musman)\
**Replies:** 6\
**Last updated:** [August 6, 2020, 3:22pm UTC](https://discourse.julialang.org/t/managing-larger-project-in-julia/44413 "2020-08-06T15:22:27Z")

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Hi, Coming from the MATLAB background where a large project can be handled pretty easily by calling out all the other functions, which are written in separate .m files, into a Main.m file (the name Main is arbitrary) an…

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## [Julia Lang and VLSI design](https://discourse.julialang.org/t/julia-lang-and-vlsi-design/44356)

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**Author:** [@Vrucoder](https://discourse.julialang.org/u/Vrucoder)\
**Replies:** 4\
**Last updated:** [August 6, 2020, 3:21pm UTC](https://discourse.julialang.org/t/julia-lang-and-vlsi-design/44356 "2020-08-06T15:21:12Z")

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It is known from various articles on internet that Julia lang has better speed and efficiency. Can it be used in place of C++/SystemC in the VLSI design fields?

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## [Establishment of 0-1 variable in JuMP](https://discourse.julialang.org/t/establishment-of-0-1-variable-in-jump/44421)

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**Author:** [@abcde](https://discourse.julialang.org/u/abcde)\
**Replies:** 2\
**Last updated:** [August 6, 2020, 2:33pm UTC](https://discourse.julialang.org/t/establishment-of-0-1-variable-in-jump/44421 "2020-08-06T14:33:04Z")

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I wrote a very simple program using JuMP model=Model(Gurobi.Optimizer) @variable(model,0\<=w\<=1,Int) @variable(model,0\<=x\[1:2,1:2\]\<=10) @constraint(model,w\*x\>=0) @objective(model,Min,-x) optimize!(model) How to mul…

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## [Deploying Julia on Heroku - Buildpacks and PackageCompiler Failing](https://discourse.julialang.org/t/deploying-julia-on-heroku-buildpacks-and-packagecompiler-failing/44043)

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**Author:** [@markhalonen](https://discourse.julialang.org/u/markhalonen)\
**Replies:** 3\
**Last updated:** [August 6, 2020, 2:02pm UTC](https://discourse.julialang.org/t/deploying-julia-on-heroku-buildpacks-and-packagecompiler-failing/44043 "2020-08-06T14:02:42Z")

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I’m trying to deploy this Julia HTTP api that simulates a coil gun using DiffEQ: https://github.com/laurium-labs/coilgunui It’s just a couple endpoints to get params and run the simulation. I’d like it to run through HT…

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## [Using multiple dispatch with parametric constructors produces ambiguous call](https://discourse.julialang.org/t/using-multiple-dispatch-with-parametric-constructors-produces-ambiguous-call/44295)

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**Author:** [@anon37204545](https://discourse.julialang.org/u/anon37204545)\
**Replies:** 8\
**Last updated:** [August 6, 2020, 1:54pm UTC](https://discourse.julialang.org/t/using-multiple-dispatch-with-parametric-constructors-produces-ambiguous-call/44295 "2020-08-06T13:54:26Z")

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This code const CompoundTuple{T} = Tuple{Compound{T}, T} struct ChemEquation{T\<:Number} tuples::Vector{CompoundTuple{T}} end ChemEquation(tuples::Vector{CompoundTuple{T}}) where T = ChemEquation{T}(tuples) ChemEqu…

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## [Splitpath and joinpath should be reversible](https://discourse.julialang.org/t/splitpath-and-joinpath-should-be-reversible/44379)

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**Author:** [@purplishrock](https://discourse.julialang.org/u/purplishrock)\
**Replies:** 6\
**Last updated:** [August 6, 2020, 1:54pm UTC](https://discourse.julialang.org/t/splitpath-and-joinpath-should-be-reversible/44379 "2020-08-06T13:54:15Z")

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Well, maybe “reversible” is not quite the right word. I was suprised this doesn’t work. julia\> x=splitpath(raw"c:\\foo\\bar\\baz") 4-element Array{String,1}: "c:\\\\" "foo" "bar" "baz" julia\> joinpath(x) ERROR: MethodE…

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## [Readavailable with timeout](https://discourse.julialang.org/t/readavailable-with-timeout/39585)

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**Author:** [@Laszlo\_Nagy](https://discourse.julialang.org/u/Laszlo_Nagy)\
**Replies:** 8\
**Last updated:** [August 6, 2020, 1:39pm UTC](https://discourse.julialang.org/t/readavailable-with-timeout/39585 "2020-08-06T13:39:36Z")

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I would like to read the first message out of a websocket as soon as it arrives, but also I want to close the connection if nothing arrives within a second. How can I do that? Example: task = @async HTTP.WebSockets.li…

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## [Compile error](https://discourse.julialang.org/t/compile-error/44368)

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**Author:** [@Fuad\_Sami](https://discourse.julialang.org/u/Fuad_Sami)\
**Replies:** 13\
**Last updated:** [August 6, 2020, 1:39pm UTC](https://discourse.julialang.org/t/compile-error/44368 "2020-08-06T13:39:20Z")

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hi all can any one tell me why this code not working ? its from function checkMagazine(magazine, note) d = Dict{String,Int}() out = "" for i in magazine if i in d d\[i\] +=1 else …

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## [Absolute value of matrix](https://discourse.julialang.org/t/absolute-value-of-matrix/44395)

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**Author:** [@dty](https://discourse.julialang.org/u/dty)\
**Replies:** 11\
**Last updated:** [August 6, 2020, 1:38pm UTC](https://discourse.julialang.org/t/absolute-value-of-matrix/44395 "2020-08-06T13:38:32Z")

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How to define the absolute value of all elements in the matrix? using JuMP,Gurobi model = Model(Gurobi.Optimizer); model=Model(Gurobi.Optimizer) T=24 @variable(model, 2 \<= a\[1:T,1:3\]\<= 2.5, Int) @variable(model,-1\<…

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## [Declaring a variable whose value cannot be changed](https://discourse.julialang.org/t/declaring-a-variable-whose-value-cannot-be-changed/44372)

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**Author:** [@Haolun\_Li](https://discourse.julialang.org/u/Haolun_Li)\
**Replies:** 2\
**Last updated:** [August 6, 2020, 1:31pm UTC](https://discourse.julialang.org/t/declaring-a-variable-whose-value-cannot-be-changed/44372 "2020-08-06T13:31:45Z")

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const x=1 then variable x’s value can be changed if a variable of the same type is reassigned. Is it possible to declare a variable so its value will NOT be changed by any assignment?

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## [List into list](https://discourse.julialang.org/t/list-into-list/44357)

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**Author:** [@Fuad\_Sami](https://discourse.julialang.org/u/Fuad_Sami)\
**Replies:** 12\
**Last updated:** [August 6, 2020, 12:58pm UTC](https://discourse.julialang.org/t/list-into-list/44357 "2020-08-06T12:58:55Z")

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hi thanks this site help me to improve my knowledge in julia, so function pair\_sum(nums, target) #Given nums = \[2, 7, 11, 15\], target = 9, d = Dict() output = Int\[\] count =0 for i in nums component = target - i …

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## [Axis ticks on top and right](https://discourse.julialang.org/t/axis-ticks-on-top-and-right/44416)

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**Author:** [@SymKo](https://discourse.julialang.org/u/SymKo)\
**Replies:** 1\
**Last updated:** [August 6, 2020, 12:44pm UTC](https://discourse.julialang.org/t/axis-ticks-on-top-and-right/44416 "2020-08-06T12:44:21Z")

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Hello, how to create axis xticks and yticks on top and right, the same like left and bottom with logarythmic scale? I don’t want to create second axis and define it. I’m using Plots.jl. When I’m using framestyle=:box, I…

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## [Access a struct field from a string](https://discourse.julialang.org/t/access-a-struct-field-from-a-string/44337)

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**Author:** [@Luigi\_Bottecchia](https://discourse.julialang.org/u/Luigi_Bottecchia)\
**Replies:** 6\
**Last updated:** [August 6, 2020, 12:22pm UTC](https://discourse.julialang.org/t/access-a-struct-field-from-a-string/44337 "2020-08-06T12:22:49Z")

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Hey Everyone! I have incurred in an issue that I believe is conceptual. I have a struct that I want to fill from a dictionary and i’m encountering problems on accessing the struct fields. The main issue is that the dic…

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## [Which approach for matrix of road journey times (i.e. routing-based distances)?](https://discourse.julialang.org/t/which-approach-for-matrix-of-road-journey-times-i-e-routing-based-distances/44407)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 1\
**Last updated:** [August 6, 2020, 11:43am UTC](https://discourse.julialang.org/t/which-approach-for-matrix-of-road-journey-times-i-e-routing-based-distances/44407 "2020-08-06T11:43:27Z")

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I need to get a matrix of road journey times by geographical coordinate pairs. I have colleagues that are using for this the R package osrm that in turn use the demo public server of project osrm, where they run their m…

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## [Plotting range of columns](https://discourse.julialang.org/t/plotting-range-of-columns/43959)

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**Author:** [@HelgavonLichtenstein](https://discourse.julialang.org/u/HelgavonLichtenstein)\
**Replies:** 1\
**Last updated:** [August 6, 2020, 11:10am UTC](https://discourse.julialang.org/t/plotting-range-of-columns/43959 "2020-08-06T11:10:41Z")

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Hello, when I use the example from GitHub - JuliaPlots/StatsPlots.jl: Statistical plotting recipes for Plots.jl using DataFrames, StatsPlots df = DataFrame(a = 1:10, b = 10 .\* rand(10), c = 10 .\* rand(10)) @df df plot(:…

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## [Windows Chocolatey package manager has v1.5.0](https://discourse.julialang.org/t/windows-chocolatey-package-manager-has-v1-5-0/44410)

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**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 0\
**Last updated:** [August 6, 2020, 10:10am UTC](https://discourse.julialang.org/t/windows-chocolatey-package-manager-has-v1-5-0/44410 "2020-08-06T10:10:35Z")

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I have recently been using the Chocolatey package manager for Windows and woudl recommend it to everyone. A big thanks to whoever maintains Julia here - v1.5.0 is already available.

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## [Right to left indenting](https://discourse.julialang.org/t/right-to-left-indenting/44355)

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**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 1\
**Last updated:** [August 6, 2020, 9:17am UTC](https://discourse.julialang.org/t/right-to-left-indenting/44355 "2020-08-06T09:17:44Z")

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Cmon now… we already index from 1 so we are pariahs already…

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## [Python to julia](https://discourse.julialang.org/t/python-to-julia/44343)

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**Author:** [@Fuad\_Sami](https://discourse.julialang.org/u/Fuad_Sami)\
**Replies:** 7\
**Last updated:** [August 6, 2020, 7:55am UTC](https://discourse.julialang.org/t/python-to-julia/44343 "2020-08-06T07:55:34Z")

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this is a python code that i try to convert to julia. Input: \[“bella”,“label”,“roller”\] Output: \[“e”,“l”,“l”\] class Solution: def commonChars(self, A: List\[str\]) -\> List\[str\]: check = list(A\[0\]) fo…

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## [View of LowerMatrix is not working with ldiv! and mul!](https://discourse.julialang.org/t/view-of-lowermatrix-is-not-working-with-ldiv-and-mul/44046)

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**Author:** [@mleprovost](https://discourse.julialang.org/u/mleprovost)\
**Replies:** 5\
**Last updated:** [August 6, 2020, 7:44am UTC](https://discourse.julialang.org/t/view-of-lowermatrix-is-not-working-with-ldiv-and-mul/44046 "2020-08-06T07:44:32Z")

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Hello, I am computed a large Cholesky factor L \\in R^{N,N}, and I would like to multiply and divide an array of dimension n, M with n \\leq N. I would like to use view(L,1:n,1:n) but ldiv!, mul! are not defined for views…

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## [Question about EMDSetting](https://discourse.julialang.org/t/question-about-emdsetting/44385)

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**Author:** [@abcde](https://discourse.julialang.org/u/abcde)\
**Replies:** 1\
**Last updated:** [August 6, 2020, 7:15am UTC](https://discourse.julialang.org/t/question-about-emdsetting/44385 "2020-08-06T07:15:58Z")

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using EmpiricalModeDecomposition a=convert(Vector{Float64},rand(20)) s= EMD\_heping\_1MX\_V\_35kV1=EmpiricalModeDecomposition.hht(a,s) This is my code,I don’t know how the keyword S should be defined, this is the code in th…

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## [ARGS in REPL (customize or remove)](https://discourse.julialang.org/t/args-in-repl-customize-or-remove/44332)

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**Author:** [@anj](https://discourse.julialang.org/u/anj)\
**Replies:** 2\
**Last updated:** [August 6, 2020, 6:59am UTC](https://discourse.julialang.org/t/args-in-repl-customize-or-remove/44332 "2020-08-06T06:59:51Z")

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Then I start REPL I already see ARGS populated julia\> ARGS 4-element Array{String,1}: "\\\\\\\\.\\\\pipe\\\\vsc-julia-repl-23904" "\\\\\\\\.\\\\pipe\\\\vsc-jl-cr-23904" "USE\_REVISE" "USE\_PLOTPANE" The questions are: is there a w…

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## [Solve system of nonlinear equations w/ Newton-Raphson iteration](https://discourse.julialang.org/t/solve-system-of-nonlinear-equations-w-newton-raphson-iteration/44383)

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**Author:** [@Albert\_Zevelev](https://discourse.julialang.org/u/Albert_Zevelev)\
**Replies:** 10\
**Last updated:** [August 6, 2020, 5:31am UTC](https://discourse.julialang.org/t/solve-system-of-nonlinear-equations-w-newton-raphson-iteration/44383 "2020-08-06T05:31:00Z")

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Consider a boring system of 4 nonlinear equations in 4 variables: a=bcd a+b=cd a+b+c=d a+b+c+d=1 Solution: (a,b,c,d)=(\\frac{1}{42}, \\frac{1}{7}, \\frac{1}{3}, \\frac{1}{2}) My code: using Zygote; NR(x0) = x0 - (fp(x…

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## [Question about Types](https://discourse.julialang.org/t/question-about-types/44386)

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**Author:** [@abcde](https://discourse.julialang.org/u/abcde)\
**Replies:** 9\
**Last updated:** [August 6, 2020, 4:22am UTC](https://discourse.julialang.org/t/question-about-types/44386 "2020-08-06T04:22:19Z")

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a=convert(Vector{Float64},rand(20)) In Workplace it is of type Vector, but in REPL it is of type Array. Why is that?Thank you very much!

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