# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1938

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

**Page:** 1939

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## [Threads are disabled if an error occurs](https://discourse.julialang.org/t/threads-are-disabled-if-an-error-occurs/27738)

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**Author:** [@ranocha](https://discourse.julialang.org/u/ranocha)\
**Replies:** 2\
**Last updated:** [August 20, 2019, 6:12am UTC](https://discourse.julialang.org/t/threads-are-disabled-if-an-error-occurs/27738 "2019-08-20T06:12:08Z")

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When an error is thrown in a threaded loop, only one thread is used in threaded loops thereafter. julia\> function f!(a) Threads.@threads for i in eachindex(a) a\[i\] = Threads.threadid() …

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## [How to plot a surface with Makie by using corner points?](https://discourse.julialang.org/t/how-to-plot-a-surface-with-makie-by-using-corner-points/27707)

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**Author:** [@Manu\_Francis](https://discourse.julialang.org/u/Manu_Francis)\
**Replies:** 4\
**Last updated:** [August 20, 2019, 3:28am UTC](https://discourse.julialang.org/t/how-to-plot-a-surface-with-makie-by-using-corner-points/27707 "2019-08-20T03:28:59Z")

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Hi, I have x, y, z corner points of a plane as follows. x = \[-24.576 24.576 24.576 -24.576\] y = \[20.0 20.0 20.0 20.0\] z = \[-24.576 -24.576 24.576 24.576\] I am trying to plot the surface with Makie using following com…

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## [JuliaML organization and MLJ.jl](https://discourse.julialang.org/t/juliaml-organization-and-mlj-jl/27342)

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**Author:** [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Replies:** 5\
**Last updated:** [August 19, 2019, 7:49pm UTC](https://discourse.julialang.org/t/juliaml-organization-and-mlj-jl/27342 "2019-08-19T19:49:43Z")

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I would like to take this opportunity to ask the community about the future of ML in Julia, and how the existing efforts interact. I am particularly interested in understanding to what extent the JuliaML organization and…

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## [Newbie mathopt question: JuMP declare or restrain a variable to a few integers, not in a row](https://discourse.julialang.org/t/newbie-mathopt-question-jump-declare-or-restrain-a-variable-to-a-few-integers-not-in-a-row/27726)

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**Author:** [@bhalonen](https://discourse.julialang.org/u/bhalonen)\
**Replies:** 2\
**Last updated:** [August 19, 2019, 7:17pm UTC](https://discourse.julialang.org/t/newbie-mathopt-question-jump-declare-or-restrain-a-variable-to-a-few-integers-not-in-a-row/27726 "2019-08-19T19:17:39Z")

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I am looking to be able to declare a vector of integer variables and restrain them to 1, 2, 3 … some finite number of non sequential integers. Should I create some roundabout lookup table to interpret sequential integers…

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## [GTK and "libgtk-3"](https://discourse.julialang.org/t/gtk-and-libgtk-3/27699)

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**Author:** [@jar](https://discourse.julialang.org/u/jar)\
**Replies:** 3\
**Last updated:** [August 19, 2019, 5:17pm UTC](https://discourse.julialang.org/t/gtk-and-libgtk-3/27699 "2019-08-19T17:17:44Z")

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I try to see an image from vscode, but it doesn’t work, from REPL everything well, but Code doesn’t work: using Plots, FileIO, ImageView img = load(“/Users/jar/src/julia/lena\_color\_512.tif”) plot(img) The error is th…

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## [Problem adding SPICE dependency into a custom module](https://discourse.julialang.org/t/problem-adding-spice-dependency-into-a-custom-module/27711)

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**Author:** [@Calum\_H](https://discourse.julialang.org/u/Calum_H)\
**Replies:** 1\
**Last updated:** [August 19, 2019, 4:54pm UTC](https://discourse.julialang.org/t/problem-adding-spice-dependency-into-a-custom-module/27711 "2019-08-19T16:54:12Z")

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Hi all, I’m writing a custom module “MyModule” in my local users/calum/.julia/dev. In MyModule i have a few dependencies that I added manually to the project.toml: \[deps\] LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fc…

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## [Array of boxes using Makie and volume](https://discourse.julialang.org/t/array-of-boxes-using-makie-and-volume/27350)

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**Author:** [@lazarusA](https://discourse.julialang.org/u/lazarusA)\
**Replies:** 7\
**Last updated:** [August 19, 2019, 1:48pm UTC](https://discourse.julialang.org/t/array-of-boxes-using-makie-and-volume/27350 "2019-08-19T13:48:54Z")

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Hi, the examples from the Makie documentation show how to build a cube (using volume), but if I try to update the scene with a new one, they overlap. Any ideas on how to solve this. I want to create an array of cubes. u…

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## [Inconsistent results when using split-apply-combine for DataFrames](https://discourse.julialang.org/t/inconsistent-results-when-using-split-apply-combine-for-dataframes/27705)

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**Author:** [@rocflight83](https://discourse.julialang.org/u/rocflight83)\
**Replies:** 7\
**Last updated:** [August 19, 2019, 1:00pm UTC](https://discourse.julialang.org/t/inconsistent-results-when-using-split-apply-combine-for-dataframes/27705 "2019-08-19T13:00:56Z")

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I’m looking to add a column to my DataFrame combo2 that represents the ranking of DK\_points by each Pos (position) group with the following code. sort!(combo2, \[:Pos, :DK\_points\], rev=\[true, true\]) dk\_rank = \[\] for pos…

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## [Efficient multiplication of out-of-memory sparse matrix and an in-memory dense vector](https://discourse.julialang.org/t/efficient-multiplication-of-out-of-memory-sparse-matrix-and-an-in-memory-dense-vector/19663)

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**Author:** [@pablosanjose](https://discourse.julialang.org/u/pablosanjose)\
**Replies:** 7\
**Last updated:** [August 19, 2019, 12:27pm UTC](https://discourse.julialang.org/t/efficient-multiplication-of-out-of-memory-sparse-matrix-and-an-in-memory-dense-vector/19663 "2019-08-19T12:27:55Z")

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Say I have a really huge sparse matrix A, and an equally huge dense vector v. I need to do A \* v. The structure of A is simple, like a -1 -1 4 -1 -1 stencil in 2D for example (in practice it’s a bit more complicated) so …

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## [What exactly is the meaning of "get!(Set{Int}, intersections, highway.nodes\[I\])" in the following code?](https://discourse.julialang.org/t/what-exactly-is-the-meaning-of-get-set-int-intersections-highway-nodes-i-in-the-following-code/27690)

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**Author:** [@bsnyh](https://discourse.julialang.org/u/bsnyh)\
**Replies:** 3\
**Last updated:** [August 19, 2019, 10:33am UTC](https://discourse.julialang.org/t/what-exactly-is-the-meaning-of-get-set-int-intersections-highway-nodes-i-in-the-following-code/27690 "2019-08-19T10:33:21Z")

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Hi, I was wondering, could anyone help me with clarifying a little bit of a line of the following code? ###################################### ### Find Intersections of Highways ### #####################################…

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## [Plotting from vscode](https://discourse.julialang.org/t/plotting-from-vscode/12009)

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**Author:** [@sbacelar](https://discourse.julialang.org/u/sbacelar)\
**Replies:** 11\
**Last updated:** [August 19, 2019, 6:29am UTC](https://discourse.julialang.org/t/plotting-from-vscode/12009 "2019-08-19T06:29:02Z")

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I am trying a simple plot using vscode: using PyPlot x = linspace(0, 10, 200); y = sin.(x); plot(x, y, "b-", linewidth=2) And the result is simply PyObject \<matplotlib.lines.Line2D object at 0x1249b77f0\> and no graph! …

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## [Alternative Complex type](https://discourse.julialang.org/t/alternative-complex-type/26668)

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**Author:** [@feanor12](https://discourse.julialang.org/u/feanor12)\
**Replies:** 6\
**Last updated:** [August 19, 2019, 4:05am UTC](https://discourse.julialang.org/t/alternative-complex-type/26668 "2019-08-19T04:05:58Z")

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Is there a complex type saving the angle and the radius instead of the imaginary and the real part? I think if there are a lot of multiplications this would be faster.

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## [Julia OOP example](https://discourse.julialang.org/t/julia-oop-example/27568)

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**Author:** [@zhangliye](https://discourse.julialang.org/u/zhangliye)\
**Replies:** 9\
**Last updated:** [August 19, 2019, 12:58am UTC](https://discourse.julialang.org/t/julia-oop-example/27568 "2019-08-19T00:58:54Z")

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I am a C++ and Python user and quite accustomed to OOP for some tasks. The following is a small example of using OOP style in Julia. Please give comments if there are better ways to do that. Thank! Hope it could help th…

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## [Import a module within that same module for parallelisation](https://discourse.julialang.org/t/import-a-module-within-that-same-module-for-parallelisation/27667)

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**Author:** [@s-baumann](https://discourse.julialang.org/u/s-baumann)\
**Replies:** 4\
**Last updated:** [August 18, 2019, 9:30pm UTC](https://discourse.julialang.org/t/import-a-module-within-that-same-module-for-parallelisation/27667 "2019-08-18T21:30:09Z")

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I have a bunch of functions within a module. I want to make a function that uses various other functions within that module in parallel. The solution that works in the REPL is to addprocs for the number of cores I have a…

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## [Round float with Julia 1.1](https://discourse.julialang.org/t/round-float-with-julia-1-1/27683)

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**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 3\
**Last updated:** [August 18, 2019, 8:49pm UTC](https://discourse.julialang.org/t/round-float-with-julia-1-1/27683 "2019-08-18T20:49:32Z")

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Hello, I am trying to round a number to the 3rd decimal with Julia 1.1 but I have issues: julia\> beta 0.005208333333333333 julia\> round(beta, 3) ERROR: MethodError: no method matching round(::Float64, ::Int64) Closest c…

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## [Optim.jl with autodiff and complex numbers](https://discourse.julialang.org/t/optim-jl-with-autodiff-and-complex-numbers/27684)

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**Author:** [@Dandan](https://discourse.julialang.org/u/Dandan)\
**Replies:** 8\
**Last updated:** [August 18, 2019, 8:03pm UTC](https://discourse.julialang.org/t/optim-jl-with-autodiff-and-complex-numbers/27684 "2019-08-18T20:03:03Z")

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Hello! I would like to use Optim.jl with the target function defined on a complex Stiefel manifold (unitary matrices) of some large size. Stiefel manifold is already implemented in Optim.jl. The problem is I can’t use …

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## [Changing the righthand side in a callback](https://discourse.julialang.org/t/changing-the-righthand-side-in-a-callback/27462)

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**Author:** [@FHell](https://discourse.julialang.org/u/FHell)\
**Replies:** 6\
**Last updated:** [August 18, 2019, 6:31pm UTC](https://discourse.julialang.org/t/changing-the-righthand-side-in-a-callback/27462 "2019-08-18T18:31:31Z")

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Hi everyone, I am wondering how to correctly change the right hand side inside a DifferentialEquations callback. If I don’t reinit the system runs through but gives wrong results (compared to just running new different…

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## [Is there a julia equivalent of R's sink() function?](https://discourse.julialang.org/t/is-there-a-julia-equivalent-of-rs-sink-function/27675)

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**Author:** [@DoktorMike](https://discourse.julialang.org/u/DoktorMike)\
**Replies:** 2\
**Last updated:** [August 18, 2019, 6:00pm UTC](https://discourse.julialang.org/t/is-there-a-julia-equivalent-of-rs-sink-function/27675 "2019-08-18T18:00:38Z")

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From time to time I would like to verbatim redirect output normally shown in the julia REPL to a text file. In R I do this by sink('txtfile.txt') interestingfunctionwithoutputs() sink() Does something like this exist i…

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## [Grassman algebras for electromagnetic scattering](https://discourse.julialang.org/t/grassman-algebras-for-electromagnetic-scattering/27681)

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**Author:** [@chakravala](https://discourse.julialang.org/u/chakravala)\
**Replies:** 7\
**Last updated:** [August 18, 2019, 2:53pm UTC](https://discourse.julialang.org/t/grassman-algebras-for-electromagnetic-scattering/27681 "2019-08-18T14:53:05Z")

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All of the math you are trying to do here could be simplified by using Grassmann.jl multivectors instead of matrices. It encodes both rotational algebras as well as spacetime geometry, so that matrices are no longer need…

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## [Qr decomposition matrix type](https://discourse.julialang.org/t/qr-decomposition-matrix-type/27566)

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**Author:** [@\_dominic](https://discourse.julialang.org/u/_dominic)\
**Replies:** 6\
**Last updated:** [August 18, 2019, 2:28pm UTC](https://discourse.julialang.org/t/qr-decomposition-matrix-type/27566 "2019-08-18T14:28:13Z")

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I just want to compute a qr decomposition and pass the Q matrix to the log function using LinearAlgebra D = rand(Float64, 3, 3) Q, R = qr(D) W = log(Q) # Error Why is Q not a simple regular matrix type? How can I con…

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## [Make clean changes package registration?](https://discourse.julialang.org/t/make-clean-changes-package-registration/27680)

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**Author:** [@Colin\_Beckingham](https://discourse.julialang.org/u/Colin_Beckingham)\
**Replies:** 1\
**Last updated:** [August 18, 2019, 2:25pm UTC](https://discourse.julialang.org/t/make-clean-changes-package-registration/27680 "2019-08-18T14:25:36Z")

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I frequently recompile the latest Julia master for experimental reasons. Occasionally the recompile fails and suggests that I do a make clean and try make again which pretty much resolves the issue. I’m wondering if the …

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## [Moving from a standalone script to a package for local use](https://discourse.julialang.org/t/moving-from-a-standalone-script-to-a-package-for-local-use/27666)

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**Author:** [@baptiste](https://discourse.julialang.org/u/baptiste)\
**Replies:** 7\
**Last updated:** [August 18, 2019, 10:47am UTC](https://discourse.julialang.org/t/moving-from-a-standalone-script-to-a-package-for-local-use/27666 "2019-08-18T10:47:18Z")

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Disclaimer: I’m relatively set in my ways with a decade of using R, and probably a bit spoiled by it when it comes to packages. I currently have a working piece of Julia code as a standalone script, with a dozen functio…

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## [Julia and Python optimization programmer with machine learning experience](https://discourse.julialang.org/t/julia-and-python-optimization-programmer-with-machine-learning-experience/27602)

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**Author:** [@GdMacmillan](https://discourse.julialang.org/u/GdMacmillan)\
**Replies:** 5\
**Last updated:** [August 18, 2019, 9:15am UTC](https://discourse.julialang.org/t/julia-and-python-optimization-programmer-with-machine-learning-experience/27602 "2019-08-18T09:15:57Z")

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Built production Python library used to convert electromagnetic data from physical sensors to real valued power flow models. Worked with technical directory to turn scripts written in Scilab to a data science toolkit in …

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## [How to using Japanese characteristic in plot](https://discourse.julialang.org/t/how-to-using-japanese-characteristic-in-plot/27613)

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**Author:** [@Nguyen\_HongSon](https://discourse.julialang.org/u/Nguyen_HongSon)\
**Replies:** 6\
**Last updated:** [August 18, 2019, 9:12am UTC](https://discourse.julialang.org/t/how-to-using-japanese-characteristic-in-plot/27613 "2019-08-18T09:12:30Z")

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Hi every body, I am very new about the Julia and Juliabox also. I am making a graphs using PyPlot on Juliabox. I want to set Legend and axes labels in Japanese. But it is not work at all, the Japanese park is shown a…

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## [Update on julia-client 0.9.4 fails](https://discourse.julialang.org/t/update-on-julia-client-0-9-4-fails/27653)

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**Author:** [@OvidiusCicero](https://discourse.julialang.org/u/OvidiusCicero)\
**Replies:** 5\
**Last updated:** [August 18, 2019, 7:36am UTC](https://discourse.julialang.org/t/update-on-julia-client-0-9-4-fails/27653 "2019-08-18T07:36:15Z")

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I get the follwoing error message on a Windows 10 machine. Julia packages are up to date. \> @pfitzseb/node-pty-prebuilt@0.8.1-prebuilt3 install C:\\Users\\CHRIST~1\\AppData\\Local\\Temp\\apm-install-dir-119717-2192-1uotbmw.vg…

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## [Pkg3 and standard libraries](https://discourse.julialang.org/t/pkg3-and-standard-libraries/9287)

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**Author:** [@dmbates](https://discourse.julialang.org/u/dmbates)\
**Replies:** 21\
**Last updated:** [August 18, 2019, 6:44am UTC](https://discourse.julialang.org/t/pkg3-and-standard-libraries/9287 "2019-08-18T06:44:14Z")

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Encouraged by a commit message on the main repository I started using Pkg3 on my locally compiled version of master. I am working on revisions to the PDMats package for Julia v0.7 so I begin with using LinearAlgebra w…

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## [Custom Flux loss function \`culiteral\_pow()\` error](https://discourse.julialang.org/t/custom-flux-loss-function-culiteral-pow-error/27671)

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**Author:** [@jchen975](https://discourse.julialang.org/u/jchen975)\
**Replies:** 2\
**Last updated:** [August 18, 2019, 6:16am UTC](https://discourse.julialang.org/t/custom-flux-loss-function-culiteral-pow-error/27671 "2019-08-18T06:16:27Z")

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Hi, I’m trying to build a MLP for a regression problem. A sample of my data looks like this: x= \\left\[ {\\begin{array}{c} \\hat{m\_1}\\\\ \\vdots \\\\ \\hat{m\_k}\\\\ \\hat{n\_1}\\\\ \\vdots \\\\ \\hat{n\_k}\\\\ P \\…

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## [LinearIndices for non-1-based indices](https://discourse.julialang.org/t/linearindices-for-non-1-based-indices/26906)

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**Author:** [@greg\_plowman](https://discourse.julialang.org/u/greg_plowman)\
**Replies:** 5\
**Last updated:** [August 17, 2019, 11:59pm UTC](https://discourse.julialang.org/t/linearindices-for-non-1-based-indices/26906 "2019-08-17T23:59:34Z")

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I’m not sure if I understand LinearIndices and CartesianIndices correctly, but I think they provide a mapping between those index types, and are inverses of each other? This seems to be the case for normal 1-based indic…

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## [Makie adjust scene limits + scale](https://discourse.julialang.org/t/makie-adjust-scene-limits-scale/27663)

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**Author:** [@jw3126](https://discourse.julialang.org/u/jw3126)\
**Replies:** 2\
**Last updated:** [August 17, 2019, 8:37pm UTC](https://discourse.julialang.org/t/makie-adjust-scene-limits-scale/27663 "2019-08-17T20:37:33Z")

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I want to animate a sequence of lines, where the x values of each line are fixed, but the y values vary in scale. Something like this: julia\> using Makie julia\> scene = Scene(); y = Node(randn(10)); lines!(scene, y) j…

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## [An example application used at an organization (generating buy-in)](https://discourse.julialang.org/t/an-example-application-used-at-an-organization-generating-buy-in/27664)

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**Author:** [@Nosferican](https://discourse.julialang.org/u/Nosferican)\
**Replies:** 0\
**Last updated:** [August 17, 2019, 8:30pm UTC](https://discourse.julialang.org/t/an-example-application-used-at-an-organization-generating-buy-in/27664 "2019-08-17T20:30:17Z")

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I wanted to share my first Julia application as part of my research lab. https://github.com/uva-bi-sdad/GitHubAPI.jl I plan to use this application to introduce my colleagues to the Julia language. The initial reaction…

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