# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1802

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

**Page:** 1803

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## [Achieving parallel web request handling with Julia (httpserver.jl or other)](https://discourse.julialang.org/t/achieving-parallel-web-request-handling-with-julia-httpserver-jl-or-other/10670)

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**Author:** [@dbartow](https://discourse.julialang.org/u/dbartow)\
**Replies:** 15\
**Last updated:** [March 13, 2020, 7:02am UTC](https://discourse.julialang.org/t/achieving-parallel-web-request-handling-with-julia-httpserver-jl-or-other/10670 "2020-03-13T07:02:26Z")

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I’ve written a web server in Julia using httpserver.jl. For simplicity, let’s say that I have one endpoint that runs a Julia function to crunch some numbers and then return them to the browser. Let’s also assume for sa…

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## [Way to make custom transformer with ScikitLearn.jl](https://discourse.julialang.org/t/way-to-make-custom-transformer-with-scikitlearn-jl/35860)

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**Author:** [@djsegal](https://discourse.julialang.org/u/djsegal)\
**Replies:** 2\
**Last updated:** [March 13, 2020, 4:49am UTC](https://discourse.julialang.org/t/way-to-make-custom-transformer-with-scikitlearn-jl/35860 "2020-03-13T04:49:20Z")

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Was trying to make an oversampler that fits in with the ScikitLearn.jl package, but it seems like only BaseRegressor is supported. Has anyone figured out a way to make custom transformers for ScikitLearn in Julia?

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## [Assigning a function to unicode symbols](https://discourse.julialang.org/t/assigning-a-function-to-unicode-symbols/35909)

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**Author:** [@hros](https://discourse.julialang.org/u/hros)\
**Replies:** 1\
**Last updated:** [March 13, 2020, 2:00am UTC](https://discourse.julialang.org/t/assigning-a-function-to-unicode-symbols/35909 "2020-03-13T02:00:21Z")

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I tried to assign a function to a unicode symbol and found out that while this works for most supported unicode symbols it fails for some. specifically, you can see that Julia seems to be picky regarding assignment of \\…

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## [Installing H2o and XGBoost on Windows 10](https://discourse.julialang.org/t/installing-h2o-and-xgboost-on-windows-10/12373)

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**Author:** [@Deb\_Midya](https://discourse.julialang.org/u/Deb_Midya)\
**Replies:** 3\
**Last updated:** [March 13, 2020, 12:06am UTC](https://discourse.julialang.org/t/installing-h2o-and-xgboost-on-windows-10/12373 "2020-03-13T00:06:45Z")

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Hi all, Thanks in advance. I’m using JuliaPro-0.6.3.1 on Windows 10 64 bit. H2o: Is the any Julia package on Windows? XGBoost: I was trying to install it using Julia\>Pkg.add(“XGBoost”). But I’ve received the this er…

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## [Why is python faster than Julia](https://discourse.julialang.org/t/why-is-python-faster-than-julia/35890)

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**Author:** [@adangreen](https://discourse.julialang.org/u/adangreen)\
**Replies:** 14\
**Last updated:** [March 12, 2020, 11:34pm UTC](https://discourse.julialang.org/t/why-is-python-faster-than-julia/35890 "2020-03-12T23:34:27Z")

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I wrote two absolutely identical pieces of code on python and Julia: from time import time start\_time = time() def euclidian\_algorithm\_division\_count(a, b): division\_count = 1 if b \> a: a, b = b, a …

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## [Recoding variables and counting and removing duplicate rows in dataframes](https://discourse.julialang.org/t/recoding-variables-and-counting-and-removing-duplicate-rows-in-dataframes/35888)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 3\
**Last updated:** [March 12, 2020, 7:29pm UTC](https://discourse.julialang.org/t/recoding-variables-and-counting-and-removing-duplicate-rows-in-dataframes/35888 "2020-03-12T19:29:50Z")

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Hi all- I seeking solutions for two problems I have encountered while manipulating dataframes. I’ve been struggling to think of a good solution. Although I can probably duct tape some solutions, I was wondering whether …

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## [Plot.jl throws "broken pipe" after closing window with gr() backend](https://discourse.julialang.org/t/plot-jl-throws-broken-pipe-after-closing-window-with-gr-backend/35873)

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**Author:** [@zierenberg](https://discourse.julialang.org/u/zierenberg)\
**Replies:** 6\
**Last updated:** [March 12, 2020, 7:07pm UTC](https://discourse.julialang.org/t/plot-jl-throws-broken-pipe-after-closing-window-with-gr-backend/35873 "2020-03-12T19:07:16Z")

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Hi, I am wondering whether the following is a bug or an error in my installation. I use Plots.jl with the gr() backend and do the following MWE julia\> using Plots julia\> plot(rand(4,4)) then I close the QT window with…

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## [Speeding up MCMC for logistic regression with large datasets using Turing or some alternative](https://discourse.julialang.org/t/speeding-up-mcmc-for-logistic-regression-with-large-datasets-using-turing-or-some-alternative/35838)

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**Author:** [@HarrisonWilde](https://discourse.julialang.org/u/HarrisonWilde)\
**Replies:** 2\
**Last updated:** [March 12, 2020, 5:58pm UTC](https://discourse.julialang.org/t/speeding-up-mcmc-for-logistic-regression-with-large-datasets-using-turing-or-some-alternative/35838 "2020-03-12T17:58:19Z")

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Hi, I am running some logistic regression MCMC sampling chains using Turing and wondering how best to optimise / use multiprocessing etc. to get maximum performance. My code currently looks like this: function get\_condi…

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## [How to make compact subset queries of a dataframe?](https://discourse.julialang.org/t/how-to-make-compact-subset-queries-of-a-dataframe/35883)

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**Author:** [@HenriDeh](https://discourse.julialang.org/u/HenriDeh)\
**Replies:** 5\
**Last updated:** [March 12, 2020, 5:10pm UTC](https://discourse.julialang.org/t/how-to-make-compact-subset-queries-of-a-dataframe/35883 "2020-03-12T17:10:04Z")

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I am looking for a more elegant way to do this data\[(data.ID .== 1) .| (data.ID .== 4) .| (data.ID .== 7) .| (data.ID .== 10),: \] where data is a DataFrame. I simply want to extract rows where the ID value is one of th…

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## [What type of optimization problem is this?](https://discourse.julialang.org/t/what-type-of-optimization-problem-is-this/35882)

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**Author:** [@marcus](https://discourse.julialang.org/u/marcus)\
**Replies:** 5\
**Last updated:** [March 12, 2020, 4:25pm UTC](https://discourse.julialang.org/t/what-type-of-optimization-problem-is-this/35882 "2020-03-12T16:25:20Z")

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Hi all. I have a constrained optimization problem which looks like it might belong to a known class. The problem is to maximize the quotient \\dfrac{x^T A x}{x^T B x} w.r.t real vector x, subject to the constraint x^T x …

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## [Does Ipopt have the option to do numerical derivatives for non-differentiable function?](https://discourse.julialang.org/t/does-ipopt-have-the-option-to-do-numerical-derivatives-for-non-differentiable-function/35887)

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**Author:** [@zxjroger](https://discourse.julialang.org/u/zxjroger)\
**Replies:** 0\
**Last updated:** [March 12, 2020, 3:56pm UTC](https://discourse.julialang.org/t/does-ipopt-have-the-option-to-do-numerical-derivatives-for-non-differentiable-function/35887 "2020-03-12T15:56:26Z")

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I am trying to compare different solvers/routines on minimizing the objective function of simulated method of moments. This objective function is non-differentiable. I wonder if there is a setting in Ipopt to do numerica…

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## [Deleting edges from SimpleWeightedDiGraph based on edge weight](https://discourse.julialang.org/t/deleting-edges-from-simpleweighteddigraph-based-on-edge-weight/35835)

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**Author:** [@Jakob](https://discourse.julialang.org/u/Jakob)\
**Replies:** 4\
**Last updated:** [March 12, 2020, 3:27pm UTC](https://discourse.julialang.org/t/deleting-edges-from-simpleweighteddigraph-based-on-edge-weight/35835 "2020-03-12T15:27:49Z")

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Hi, i would like to remove multiple edges from a SimpleWeightedDiGraph based on their weight. However, naively looping over edges as in the example below does not yield the desired result, presumably because the intern…

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## [How can I clear (i.e., not overlay) my plot in Atom?](https://discourse.julialang.org/t/how-can-i-clear-i-e-not-overlay-my-plot-in-atom/35861)

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**Author:** [@Farhan\_Samir](https://discourse.julialang.org/u/Farhan_Samir)\
**Replies:** 2\
**Last updated:** [March 12, 2020, 2:59pm UTC](https://discourse.julialang.org/t/how-can-i-clear-i-e-not-overlay-my-plot-in-atom/35861 "2020-03-12T14:59:35Z")

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If I understand correctly, using plot(...) as opposed to plot!(...) should replace the contents of the old plot with the new. I’m using the former to create plots but they seem to be overlayed for some reason, and I can’…

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## [Has there been any consideration to investing in vscode?](https://discourse.julialang.org/t/has-there-been-any-consideration-to-investing-in-vscode/35740)

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**Author:** [@Rana\_Ian](https://discourse.julialang.org/u/Rana_Ian)\
**Replies:** 12\
**Last updated:** [March 12, 2020, 2:52pm UTC](https://discourse.julialang.org/t/has-there-been-any-consideration-to-investing-in-vscode/35740 "2020-03-12T14:52:47Z")

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Julia’s IDE integration with Atom through Juno is superb. It seems that a lot of effort has been put into Juno to make the Julia experience first-class in Atom. With that said, Visual Studio Code has come along way, and…

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## [Help with type inference](https://discourse.julialang.org/t/help-with-type-inference/35753)

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**Author:** [@pdeffebach](https://discourse.julialang.org/u/pdeffebach)\
**Replies:** 17\
**Last updated:** [March 12, 2020, 2:25pm UTC](https://discourse.julialang.org/t/help-with-type-inference/35753 "2020-03-12T14:25:19Z")

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I have an odd problem with type inference. I am writing an iterator which wraps a vector. The following is NOT an MWE as I cannot reproduce the error in a small example. However hopefully it can still lead to a solution. …

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## [Understanding the structure of projects](https://discourse.julialang.org/t/understanding-the-structure-of-projects/35814)

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**Author:** [@Lorenzo](https://discourse.julialang.org/u/Lorenzo)\
**Replies:** 5\
**Last updated:** [March 12, 2020, 2:22pm UTC](https://discourse.julialang.org/t/understanding-the-structure-of-projects/35814 "2020-03-12T14:22:50Z")

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Hi! This is my second super-newbie question, I hope you’re so kind to help me since this will be quite a broad one. A little background: I’m at my first year (of probably 5) of a CS degree and I have been programming f…

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## [Using Blink, Interact and PlotyJS together](https://discourse.julialang.org/t/using-blink-interact-and-plotyjs-together/29241)

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**Author:** [@amit112amit](https://discourse.julialang.org/u/amit112amit)\
**Replies:** 2\
**Last updated:** [March 12, 2020, 1:19pm UTC](https://discourse.julialang.org/t/using-blink-interact-and-plotyjs-together/29241 "2020-03-12T13:19:39Z")

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Hi. As far as I could find, we cannot use Interact.@manipulate with PlotlyJS in a Jupyterlab notebook to make interactive plots. I was able to use GR and PyPlot but I prefer using PlotlyJS because it allows me to update…

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## [Scientific Programmer/Data Expert for Model-Data integration in Biogeochemistry Jena (Germany)](https://discourse.julialang.org/t/scientific-programmer-data-expert-for-model-data-integration-in-biogeochemistry-jena-germany/35878)

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**Author:** [@fabiangans](https://discourse.julialang.org/u/fabiangans)\
**Replies:** 0\
**Last updated:** [March 12, 2020, 1:10pm UTC](https://discourse.julialang.org/t/scientific-programmer-data-expert-for-model-data-integration-in-biogeochemistry-jena-germany/35878 "2020-03-12T13:10:43Z")

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You can find the full job description here https://www.bgc-jena.mpg.de/www/uploads/Career/OpenPositions/20200309\_programmer.pdf

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## [Spherical Harmonic transforms using Julia](https://discourse.julialang.org/t/spherical-harmonic-transforms-using-julia/35824)

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**Author:** [@SMH](https://discourse.julialang.org/u/SMH)\
**Replies:** 4\
**Last updated:** [March 12, 2020, 11:37am UTC](https://discourse.julialang.org/t/spherical-harmonic-transforms-using-julia/35824 "2020-03-12T11:37:32Z")

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Hello, I want to compute forward and inverse spherical harmonic transforms in Julia. I tried using FastTransforms but the package appears to be unstable (on the Mac Desktop, at any rate) and I also can’t seem to control…

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## [Note: Job post specifically relevant to the GEO domain](https://discourse.julialang.org/t/note-job-post-specifically-relevant-to-the-geo-domain/35877)

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**Author:** [@mafla](https://discourse.julialang.org/u/mafla)\
**Replies:** 0\
**Last updated:** [March 12, 2020, 11:34am UTC](https://discourse.julialang.org/t/note-job-post-specifically-relevant-to-the-geo-domain/35877 "2020-03-12T11:34:28Z")

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## [PackageCompiler for a beginner?](https://discourse.julialang.org/t/packagecompiler-for-a-beginner/35876)

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**Author:** [@Darione](https://discourse.julialang.org/u/Darione)\
**Replies:** 0\
**Last updated:** [March 12, 2020, 10:12am UTC](https://discourse.julialang.org/t/packagecompiler-for-a-beginner/35876 "2020-03-12T10:12:15Z")

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Is it possible to have a simpler example of using PackageCompiler, addressed to the beginner? Let’s put ourselves in the shoes of him, for a moment. He is trying to use Julia, and we suppose he is very happy with it. H…

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## [Scientist in Earth System Data Science / Leipzig University / Germany](https://discourse.julialang.org/t/scientist-in-earth-system-data-science-leipzig-university-germany/35871)

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**Author:** [@mafla](https://discourse.julialang.org/u/mafla)\
**Replies:** 0\
**Last updated:** [March 12, 2020, 9:02am UTC](https://discourse.julialang.org/t/scientist-in-earth-system-data-science-leipzig-university-germany/35871 "2020-03-12T09:02:05Z")

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Dear Julia GEO community, I am looking for a highly motived PostDoc. Please do not hesitate to contact me directly for more information (the terms and conditions are probably a bit hard to understand as they refer to sp…

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## [How run script in Juno with parameters?](https://discourse.julialang.org/t/how-run-script-in-juno-with-parameters/35362)

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**Author:** [@Darione](https://discourse.julialang.org/u/Darione)\
**Replies:** 12\
**Last updated:** [March 12, 2020, 8:46am UTC](https://discourse.julialang.org/t/how-run-script-in-juno-with-parameters/35362 "2020-03-12T08:46:30Z")

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Is possible to run Julia file in Juno , as running it as command line passing it some arguments? i don’t know where i can specify arguments in running a script in Juno …

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## [Performance of power as function input](https://discourse.julialang.org/t/performance-of-power-as-function-input/35852)

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**Author:** [@MrUrq](https://discourse.julialang.org/u/MrUrq)\
**Replies:** 3\
**Last updated:** [March 12, 2020, 7:54am UTC](https://discourse.julialang.org/t/performance-of-power-as-function-input/35852 "2020-03-12T07:54:01Z")

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Hi, I have a performance regression when including the power of a function as an input argument. I have boiled it down to something like this: function f1(X) n,d = size(X) dist = 0.0 for i = 2:n fo…

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## [Problem with Weave code](https://discourse.julialang.org/t/problem-with-weave-code/35862)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 9\
**Last updated:** [March 12, 2020, 7:40am UTC](https://discourse.julialang.org/t/problem-with-weave-code/35862 "2020-03-12T07:40:16Z")

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weave("C:/Users/brett/OneDrive/Documents/", out\_path=C:/Users/brett/OneDrive/Documents/ECON214Assignment3.pdf, doctype="md2pdf") When I put in this code I get an error. What am I doing wrong?

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## [Plotting with PGFPlots not able to superimpose graphs in a for loop](https://discourse.julialang.org/t/plotting-with-pgfplots-not-able-to-superimpose-graphs-in-a-for-loop/35782)

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**Author:** [@JosephPollacco](https://discourse.julialang.org/u/JosephPollacco)\
**Replies:** 7\
**Last updated:** [March 12, 2020, 7:37am UTC](https://discourse.julialang.org/t/plotting-with-pgfplots-not-able-to-superimpose-graphs-in-a-for-loop/35782 "2020-03-12T07:37:01Z")

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I am plotting with PGFPlots JULIA, and I would like to superimpose graphs in the loop such as in Plots by using Plot!. But I was only successful to produce separate graphs: X = ∑T\[1:θcalibr.Nt\] Plot\_θcalibr = Gro…

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## [Unexpected allocations in looped vs broadcasted functions on tuples of arrays](https://discourse.julialang.org/t/unexpected-allocations-in-looped-vs-broadcasted-functions-on-tuples-of-arrays/35855)

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**Author:** [@jlchan](https://discourse.julialang.org/u/jlchan)\
**Replies:** 4\
**Last updated:** [March 12, 2020, 7:09am UTC](https://discourse.julialang.org/t/unexpected-allocations-in-looped-vs-broadcasted-functions-on-tuples-of-arrays/35855 "2020-03-12T07:09:53Z")

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I have a function which operates on tuples of arrays using broadcasting, but I’m rewriting it because it doesn’t play well with ForwardDiff.jl. However, I’ve noticed that version which loops through array entries is slo…

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## [Add variables in a container](https://discourse.julialang.org/t/add-variables-in-a-container/35798)

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**Author:** [@remi-garcia](https://discourse.julialang.org/u/remi-garcia)\
**Replies:** 11\
**Last updated:** [March 12, 2020, 7:06am UTC](https://discourse.julialang.org/t/add-variables-in-a-container/35798 "2020-03-12T07:06:10Z")

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Hello, I’ve found a workaround to my problem but I wonder if there is a better way to solve it. This is what I do: using JuMP model = JuMP.Model() n = 10 @variable(model, -5 \<= x0 \<= 5, Int) @variable(model, -5 \<= x\[1…

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## [IDEs should have an export function](https://discourse.julialang.org/t/ides-should-have-an-export-function/35865)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 7\
**Last updated:** [March 12, 2020, 5:39am UTC](https://discourse.julialang.org/t/ides-should-have-an-export-function/35865 "2020-03-12T05:39:44Z")

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IDEs like Atom should have a drop-down export function. There is nothing more frustrating than working for hours on a document and spending more hours fighting with a function like Weave to make a pdf, html, or latex. T…

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## [Way to hide code in Weaved documents?](https://discourse.julialang.org/t/way-to-hide-code-in-weaved-documents/35380)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 6\
**Last updated:** [March 12, 2020, 5:38am UTC](https://discourse.julialang.org/t/way-to-hide-code-in-weaved-documents/35380 "2020-03-12T05:38:28Z")

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In R, if I have a code that is only for technical stuff, like: library("zoo", lib.loc="C:/software/Rpackages") I can represent the same code as \` library("zoo", lib.loc="C:/software/Rpackages") \` and it won’t show up…

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