# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1571

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

**Page:** 1572

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## [Juno debugger processes @info in unexplained way from user point of view](https://discourse.julialang.org/t/juno-debugger-processes-info-in-unexplained-way-from-user-point-of-view/50254)

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**Author:** [@xanfus](https://discourse.julialang.org/u/xanfus)\
**Replies:** 0\
**Last updated:** [November 16, 2020, 10:19pm UTC](https://discourse.julialang.org/t/juno-debugger-processes-info-in-unexplained-way-from-user-point-of-view/50254 "2020-11-16T22:19:57Z")

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@info is a task, i suppose. Because of this, execution doesn’t proceed beyond the macro. function info\_here() @info "done" end Juno.@enter info\_here() debug\> ERROR: UndefVarError: debug not defined Stacktrace: \[1\]…

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## [Improve performance of vector-matrix multiplication](https://discourse.julialang.org/t/improve-performance-of-vector-matrix-multiplication/50251)

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**Author:** [@uwechsler](https://discourse.julialang.org/u/uwechsler)\
**Replies:** 2\
**Last updated:** [November 16, 2020, 10:16pm UTC](https://discourse.julialang.org/t/improve-performance-of-vector-matrix-multiplication/50251 "2020-11-16T22:16:19Z")

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In a larger project, I have to compute a (row)vector-matrix multiplication. I guess that in mathematical terms, I would write it as c = x\\cdot M^T where x\\in \\mathbb{R}^{1 \\times n}, M^T\\in \\mathbb{R}^{n \\times m} and c…

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## [Sankey diagrams](https://discourse.julialang.org/t/sankey-diagrams/8668)

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**Author:** [@Alvaro\_Jose\_Gonzalez](https://discourse.julialang.org/u/Alvaro_Jose_Gonzalez)\
**Replies:** 3\
**Last updated:** [November 16, 2020, 9:48pm UTC](https://discourse.julialang.org/t/sankey-diagrams/8668 "2020-11-16T21:48:30Z")

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Hello everybody, Does anyone know how to create a Sankey diagram in Julia? Thanks! Alvaro

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## [Initial version of my first package: A JSON Lines reader](https://discourse.julialang.org/t/initial-version-of-my-first-package-a-json-lines-reader/44552)

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**Author:** [@danielw2904](https://discourse.julialang.org/u/danielw2904)\
**Replies:** 42\
**Last updated:** [November 16, 2020, 9:26pm UTC](https://discourse.julialang.org/t/initial-version-of-my-first-package-a-json-lines-reader/44552 "2020-11-16T21:26:32Z")

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Hi All! I have just “finished” implementing an inital version of a JSON Lines reader (JSONLines.jl) and would like to ask for some feedback. It implements a specific style of JSON Lines file used in other implementation…

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## [Krylov subspace polynomial of one right hand side, applied to another](https://discourse.julialang.org/t/krylov-subspace-polynomial-of-one-right-hand-side-applied-to-another/50250)

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**Author:** [@raminammour](https://discourse.julialang.org/u/raminammour)\
**Replies:** 0\
**Last updated:** [November 16, 2020, 9:24pm UTC](https://discourse.julialang.org/t/krylov-subspace-polynomial-of-one-right-hand-side-applied-to-another/50250 "2020-11-16T21:24:17Z")

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Hello, A Krylov subspace method (gmres, cg, minres,…) approximates the solution of a linear system, Ax=b. The solution at iteration n is a polynomial in A, applied to the right hand side b: x\_n = P\_n(A,b) b. Note that P…

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## [Autocorrelation of a vector](https://discourse.julialang.org/t/autocorrelation-of-a-vector/50249)

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**Author:** [@jzr](https://discourse.julialang.org/u/jzr)\
**Replies:** 1\
**Last updated:** [November 16, 2020, 9:23pm UTC](https://discourse.julialang.org/t/autocorrelation-of-a-vector/50249 "2020-11-16T21:23:21Z")

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https://juliastats.org/StatsBase.jl/v0.16/signalcorr.html#StatsBase.autocor If x is a vector, return a vector of the same length as x. julia\> length(autocor(randn(2000))) 34 Why isn’t the result length 2000?

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## [Chris Rackauckas awarded ISOP Emerging Scientist Award](https://discourse.julialang.org/t/chris-rackauckas-awarded-isop-emerging-scientist-award/49981)

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**Author:** [@viralbshah](https://discourse.julialang.org/u/viralbshah)\
**Replies:** 1\
**Last updated:** [November 16, 2020, 8:54pm UTC](https://discourse.julialang.org/t/chris-rackauckas-awarded-isop-emerging-scientist-award/49981 "2020-11-16T20:54:28Z")

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A hearty congratulations to @ChrisRackauckas for receiving the 2020 ISoP Emerging Scientist Award. ISoP is the International Society of Pharmacometrics. Undoubtedly Julia + DiffEq + SciML has led to major advancements i…

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## [Which should I use \`\_\_init\_\_\` or \`deps/build.jl\`?](https://discourse.julialang.org/t/which-should-i-use-init-or-deps-build-jl/50216)

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**Author:** [@paalon](https://discourse.julialang.org/u/paalon)\
**Replies:** 2\
**Last updated:** [November 16, 2020, 7:26pm UTC](https://discourse.julialang.org/t/which-should-i-use-init-or-deps-build-jl/50216 "2020-11-16T19:26:26Z")

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I’m writing a module which has a CSV file as data, and should be expanded and processed to DataFrame and saved as JLD2 file. However the data size of the generated JLD2 file is much larger than original CSV file, I want …

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## [Error doing Implicit Derivatives in ModelToolkit I think it's trying to divide by 0](https://discourse.julialang.org/t/error-doing-implicit-derivatives-in-modeltoolkit-i-think-its-trying-to-divide-by-0/50240)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 2\
**Last updated:** [November 16, 2020, 7:22pm UTC](https://discourse.julialang.org/t/error-doing-implicit-derivatives-in-modeltoolkit-i-think-its-trying-to-divide-by-0/50240 "2020-11-16T19:22:40Z")

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when I try to run let ex = Differential(x)(f(x, y)) func\_ex = build\_function(expand\_derivatives(ex), x, y) @eval ∂xf(x, y) = ($func\_ex)(x,y) end I get an error ERROR: type Int64 has no fi…

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## [Overwrite Cholesky factorization](https://discourse.julialang.org/t/overwrite-cholesky-factorization/50210)

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**Author:** [@ahwillia](https://discourse.julialang.org/u/ahwillia)\
**Replies:** 3\
**Last updated:** [November 16, 2020, 7:19pm UTC](https://discourse.julialang.org/t/overwrite-cholesky-factorization/50210 "2020-11-16T19:19:25Z")

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I am trying to figure out the best way to overwrite/update a Cholesky factorization. In short, I have a symmetric matrix K which is periodically updated with new data. Every time I update K I want to recompute its Choles…

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## [Do we have something like this 🤔](https://discourse.julialang.org/t/do-we-have-something-like-this/50161)

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**Author:** [@Impressium](https://discourse.julialang.org/u/Impressium)\
**Replies:** 2\
**Last updated:** [November 16, 2020, 7:17pm UTC](https://discourse.julialang.org/t/do-we-have-something-like-this/50161 "2020-11-16T19:17:20Z")

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## [Obtain Envelope](https://discourse.julialang.org/t/obtain-envelope/46643)

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**Author:** [@carlomontec](https://discourse.julialang.org/u/carlomontec)\
**Replies:** 13\
**Last updated:** [November 16, 2020, 6:55pm UTC](https://discourse.julialang.org/t/obtain-envelope/46643 "2020-11-16T18:55:58Z")

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Hello, is there any function or library to obtain the envelope of a signal ? Thank you all.

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## [Economic Consultant role in London, UK](https://discourse.julialang.org/t/economic-consultant-role-in-london-uk/50233)

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**Author:** [@nilshg](https://discourse.julialang.org/u/nilshg)\
**Replies:** 0\
**Last updated:** [November 16, 2020, 5:01pm UTC](https://discourse.julialang.org/t/economic-consultant-role-in-london-uk/50233 "2020-11-16T17:01:01Z")

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Hi all, As some of you will know I work as an Economic Consultant in Alvarez & Marsal’s London based economic consulting team. We’re currently looking for an early career economist with a particular interest in quantit…

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## [Endianness doesn't seem to be conserved in FORTRAN shared libraries?](https://discourse.julialang.org/t/endianness-doesnt-seem-to-be-conserved-in-fortran-shared-libraries/50174)

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**Author:** [@ctessum](https://discourse.julialang.org/u/ctessum)\
**Replies:** 9\
**Last updated:** [November 16, 2020, 4:04pm UTC](https://discourse.julialang.org/t/endianness-doesnt-seem-to-be-conserved-in-fortran-shared-libraries/50174 "2020-11-16T16:04:13Z")

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Hello! I have a question regarding calling a FORTRAN shared library that needs to read a binary file that is big-endian. This is the file in question: https://github.com/wrf-model/WRF/blob/master/run/RRTMG\_LW\_DATA. I …

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## [Function that's \`not defined\` is defined](https://discourse.julialang.org/t/function-thats-not-defined-is-defined/50212)

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**Author:** [@kapple](https://discourse.julialang.org/u/kapple)\
**Replies:** 3\
**Last updated:** [November 16, 2020, 2:36pm UTC](https://discourse.julialang.org/t/function-thats-not-defined-is-defined/50212 "2020-11-16T14:36:33Z")

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The body of code is structured as function my\_fcn(...) ... if ... ... θ\_sed(r) = ... return θ\_sed, ... else ... t\_sed(r) = ... @show t\_sed(50.0) @show 2atan(t\_sed(50.0)) θ\_sed(r) = …

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## [DataInterpolations -- add information after interpolation function has been created?](https://discourse.julialang.org/t/datainterpolations-add-information-after-interpolation-function-has-been-created/50226)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 1\
**Last updated:** [November 16, 2020, 2:32pm UTC](https://discourse.julialang.org/t/datainterpolations-add-information-after-interpolation-function-has-been-created/50226 "2020-11-16T14:32:56Z")

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With package DataInterpolations – is it possible to add data after I have created an interpolation function? Example: u = \[1,2,3,4,5\] t = \[0,0.5,1,2,4\] f = ConstantInterpolation(u,t) Suppose I pass function f to some f…

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## [The Scaling and centering Matrices](https://discourse.julialang.org/t/the-scaling-and-centering-matrices/50186)

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**Author:** [@HerAdri](https://discourse.julialang.org/u/HerAdri)\
**Replies:** 6\
**Last updated:** [November 16, 2020, 2:19pm UTC](https://discourse.julialang.org/t/the-scaling-and-centering-matrices/50186 "2020-11-16T14:19:27Z")

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With what package and Julia functions the Scaling and centering Matrices is performed?

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## [Acceleration of a function](https://discourse.julialang.org/t/acceleration-of-a-function/50181)

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**Author:** [@Jonas](https://discourse.julialang.org/u/Jonas)\
**Replies:** 16\
**Last updated:** [November 16, 2020, 2:09pm UTC](https://discourse.julialang.org/t/acceleration-of-a-function/50181 "2020-11-16T14:09:49Z")

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Hello everyone, I am currently transforming some Matlab code into Julia. Everything works fine, but I recognized a big difference in runtime. I don’t have much experience in that regard, so I started reading the guideli…

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## [Bayesian estimation with Multinomial Likelihood and Dirichlet prior](https://discourse.julialang.org/t/bayesian-estimation-with-multinomial-likelihood-and-dirichlet-prior/50101)

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**Author:** [@ANasc](https://discourse.julialang.org/u/ANasc)\
**Replies:** 5\
**Last updated:** [November 16, 2020, 1:05pm UTC](https://discourse.julialang.org/t/bayesian-estimation-with-multinomial-likelihood-and-dirichlet-prior/50101 "2020-11-16T13:05:04Z")

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I’m trying to fit a parasite dynamic model to some experimental data using Turing.jl, but I’m having some trouble specifying the prior variance, σ. It works fine if I use an InverseGamma distribution (i.e., resulting par…

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## [Unreasonable GPU memory usage with PyCall](https://discourse.julialang.org/t/unreasonable-gpu-memory-usage-with-pycall/13700)

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**Author:** [@Xiucheng\_Li](https://discourse.julialang.org/u/Xiucheng_Li)\
**Replies:** 3\
**Last updated:** [November 16, 2020, 12:12pm UTC](https://discourse.julialang.org/t/unreasonable-gpu-memory-usage-with-pycall/13700 "2020-11-16T12:12:54Z")

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The GPU memory usage grows with the iteration when calling PyTorch with PyCall, I have opened an issue at github. It seems that PyTorch is unaware of the release of the local variable and I am wondering whether this is r…

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## [Array of arrays indexing problem](https://discourse.julialang.org/t/array-of-arrays-indexing-problem/50145)

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**Author:** [@amael](https://discourse.julialang.org/u/amael)\
**Replies:** 5\
**Last updated:** [November 16, 2020, 12:11pm UTC](https://discourse.julialang.org/t/array-of-arrays-indexing-problem/50145 "2020-11-16T12:11:12Z")

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Hello, If i define an array of arrays like this: a = \[ zeros(10) for i in 1:3 \] I get an array of 3 elements that are arrays of 10 elements each. Then If I call a\[2\]\[:\] I get an array of length 10 which is normal an…

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## [Error: Julia could not be started](https://discourse.julialang.org/t/error-julia-could-not-be-started/50219)

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**Author:** [@Nova](https://discourse.julialang.org/u/Nova)\
**Replies:** 7\
**Last updated:** [November 16, 2020, 10:53am UTC](https://discourse.julialang.org/t/error-julia-could-not-be-started/50219 "2020-11-16T10:53:33Z")

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I recently updated my mac and I am getting this error since then. I was using using Atom as the editor without any issue before the update. I tried the followings but none worked so far: Uninstall/install Julia client…

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## [Error with JuMP.model function](https://discourse.julialang.org/t/error-with-jump-model-function/50190)

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**Author:** [@erikbjornerem](https://discourse.julialang.org/u/erikbjornerem)\
**Replies:** 2\
**Last updated:** [November 16, 2020, 11:34am UTC](https://discourse.julialang.org/t/error-with-jump-model-function/50190 "2020-11-16T11:34:12Z")

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Hi, I’m relatively new to Julia and the JuMP package. The other day I also got the MathOptInterface package in order to export my LP model as a LP-file to be used in LPsolve by a fellow student. However after doing so I…

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## [Speed up jump diffusion solution for estimation?](https://discourse.julialang.org/t/speed-up-jump-diffusion-solution-for-estimation/43174)

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**Author:** [@mcreel](https://discourse.julialang.org/u/mcreel)\
**Replies:** 13\
**Last updated:** [November 16, 2020, 11:02am UTC](https://discourse.julialang.org/t/speed-up-jump-diffusion-solution-for-estimation/43174 "2020-11-16T11:02:13Z")

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I am interested in estimating the parameters of a jump diffusion using simulation-based methods, and filtering statistics through a neural net. The basic idea is working quite well. Now, I need to make the simulations as…

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## [Is there a command for forcing a fresh precompilation of a module?](https://discourse.julialang.org/t/is-there-a-command-for-forcing-a-fresh-precompilation-of-a-module/49730)

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**Author:** [@wg030](https://discourse.julialang.org/u/wg030)\
**Replies:** 5\
**Last updated:** [November 16, 2020, 10:21am UTC](https://discourse.julialang.org/t/is-there-a-command-for-forcing-a-fresh-precompilation-of-a-module/49730 "2020-11-16T10:21:28Z")

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Hey, I am wondering if one can force a module to be precompiled. So I am looking for a command like precompilemodule( "pathto/MyModule.jl")

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## [Index of element with lowest non-negative value](https://discourse.julialang.org/t/index-of-element-with-lowest-non-negative-value/50175)

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**Author:** [@fusion809](https://discourse.julialang.org/u/fusion809)\
**Replies:** 4\
**Last updated:** [November 16, 2020, 9:16am UTC](https://discourse.julialang.org/t/index-of-element-with-lowest-non-negative-value/50175 "2020-11-16T09:16:07Z")

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I need to be able to find the index of the element within a 1d array that has the lowest non-negative value (so excluding all negative numbers). I know one way I finding it, namely using: minVal = Inf; index = 0; for i …

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## [Why no mutating filter function for strings?](https://discourse.julialang.org/t/why-no-mutating-filter-function-for-strings/50213)

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**Author:** [@kapple](https://discourse.julialang.org/u/kapple)\
**Replies:** 7\
**Last updated:** [November 16, 2020, 9:02am UTC](https://discourse.julialang.org/t/why-no-mutating-filter-function-for-strings/50213 "2020-11-16T09:02:37Z")

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Is there a reason why julia\> str = " a" " a" julia\> filter(isspace, str) " " works but julia\> filter!(isspace, str) ERROR: MethodError: no method matching filter!(::typeof(isspace), ::String) Closest candidates are: …

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## [Use external CSS file in WebIO?](https://discourse.julialang.org/t/use-external-css-file-in-webio/50218)

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**Author:** [@Jojo\_Dad](https://discourse.julialang.org/u/Jojo_Dad)\
**Replies:** 0\
**Last updated:** [November 16, 2020, 9:02am UTC](https://discourse.julialang.org/t/use-external-css-file-in-webio/50218 "2020-11-16T09:02:15Z")

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How can I load an external CSS file in WebIO?

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## [Writing LaTeX from Julia](https://discourse.julialang.org/t/writing-latex-from-julia/50187)

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**Author:** [@fusion809](https://discourse.julialang.org/u/fusion809)\
**Replies:** 6\
**Last updated:** [November 16, 2020, 8:54am UTC](https://discourse.julialang.org/t/writing-latex-from-julia/50187 "2020-11-16T08:54:18Z")

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I’m trying to write LaTeX (which I’m sure most of you know involves a lot of backslashes, e.g. \\dfrac{3}{5} to create a fraction with numerator 3 and denominator 5) to a text file. By a DuckDuckGo search I found that sed…

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## [I wrote a guide about Object Orientation and Polymorphism in Julia. opinions wanted!](https://discourse.julialang.org/t/i-wrote-a-guide-about-object-orientation-and-polymorphism-in-julia-opinions-wanted/25425)

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**Author:** [@ninjaaron](https://discourse.julialang.org/u/ninjaaron)\
**Replies:** 61\
**Last updated:** [November 16, 2020, 8:18am UTC](https://discourse.julialang.org/t/i-wrote-a-guide-about-object-orientation-and-polymorphism-in-julia-opinions-wanted/25425 "2020-11-16T08:18:29Z")

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People seem to have a hard time grokking Julia’s approach to OO and understanding how it is possible to live without classical inheritance. I took a short break from screeching at them on Quora to write this guide about …

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