# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1659

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

**Page:** 1660

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## [How to PackageCompile ArgParse](https://discourse.julialang.org/t/how-to-packagecompile-argparse/31994)

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**Author:** [@andromodon](https://discourse.julialang.org/u/andromodon)\
**Replies:** 5\
**Last updated:** [August 14, 2020, 12:59pm UTC](https://discourse.julialang.org/t/how-to-packagecompile-argparse/31994 "2020-08-14T12:59:28Z")

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Hello! Background I’m fairly new to julia and love it’s potential, but one thing always seems to slow me down. I write scripts almost exclusively (executables with #!/path/to/julia at the top), and they’re oh-so-very-s…

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## [Question about Variable declarations](https://discourse.julialang.org/t/question-about-variable-declarations/44845)

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**Author:** [@abcde](https://discourse.julialang.org/u/abcde)\
**Replies:** 9\
**Last updated:** [August 14, 2020, 12:08pm UTC](https://discourse.julialang.org/t/question-about-variable-declarations/44845 "2020-08-14T12:08:20Z")

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In the writing process of Julia function, we need to input n as the parameter,that is function abc(data,f,n,...).I have a data matrix, and I’m going to divide the data matrix into n parts according to index f,How do I d…

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## [How to plot specific DataFrame points?](https://discourse.julialang.org/t/how-to-plot-specific-dataframe-points/44922)

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**Author:** [@HelgavonLichtenstein](https://discourse.julialang.org/u/HelgavonLichtenstein)\
**Replies:** 3\
**Last updated:** [August 14, 2020, 12:07pm UTC](https://discourse.julialang.org/t/how-to-plot-specific-dataframe-points/44922 "2020-08-14T12:07:45Z")

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In the end I want to create a scatter plot with a specific value from columns bb:ff against their corresponding value in column gg. In my case, I have a DataFrame which I pull final simulation values out of into a new Da…

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## [\`'\` or \`transpose\` failing on strings is not beginner-friendly](https://discourse.julialang.org/t/or-transpose-failing-on-strings-is-not-beginner-friendly/44926)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 2\
**Last updated:** [August 14, 2020, 11:52am UTC](https://discourse.julialang.org/t/or-transpose-failing-on-strings-is-not-beginner-friendly/44926 "2020-08-14T11:52:51Z")

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While I understand that transpose is recursive, the fact that it fails on strings (together with the beautiful ' notation) is a problem for beginners. I would vote for a less pure solution that stops the recursion for A…

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## [Log scale axis issue with PyPlot (and how to manually fix it)](https://discourse.julialang.org/t/log-scale-axis-issue-with-pyplot-and-how-to-manually-fix-it/44927)

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**Author:** [@nicolas](https://discourse.julialang.org/u/nicolas)\
**Replies:** 0\
**Last updated:** [August 14, 2020, 11:14am UTC](https://discourse.julialang.org/t/log-scale-axis-issue-with-pyplot-and-how-to-manually-fix-it/44927 "2020-08-14T11:14:25Z")

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When I execute the following code using PyPlot (Julia 1.5.0 on Windows): using Plots pyplot() scatter(1:5, \[1, 1e-5,1e-10,1e-15,1e-20\], yaxis=:log) The y axis doesn’t show properly. But I have realized by clicking on ‘…

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## [Base.Statistics -- I'm confused by the differences in arguments](https://discourse.julialang.org/t/base-statistics-im-confused-by-the-differences-in-arguments/44870)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 13\
**Last updated:** [August 14, 2020, 9:35am UTC](https://discourse.julialang.org/t/base-statistics-im-confused-by-the-differences-in-arguments/44870 "2020-08-14T09:35:48Z")

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Suppose I have a number of experiments, say 5, each of which consist of a 2x3 matrix of data. I can either organize these in a 2x3x5 array A, C, or in a vector of 5 elements of 2x3 matrices (B). For illustration: # Orga…

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## [Got \`Unreachable reached\` error while using IRTools](https://discourse.julialang.org/t/got-unreachable-reached-error-while-using-irtools/44860)

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**Author:** [@KDr2](https://discourse.julialang.org/u/KDr2)\
**Replies:** 1\
**Last updated:** [August 14, 2020, 9:33am UTC](https://discourse.julialang.org/t/got-unreachable-reached-error-while-using-irtools/44860 "2020-08-14T09:33:33Z")

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I am trying to run an example from the document of IRTools.jl, but when I run the modified IR, I got an Unreachable reached at 0x7ffad63e616d error: julia\> using IRTools julia\> f(x) = 3x + 2 f (generic function with 1 …

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## [Plotting a Plane from a function using Makie](https://discourse.julialang.org/t/plotting-a-plane-from-a-function-using-makie/44675)

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**Author:** [@fermion4](https://discourse.julialang.org/u/fermion4)\
**Replies:** 4\
**Last updated:** [August 14, 2020, 9:32am UTC](https://discourse.julialang.org/t/plotting-a-plane-from-a-function-using-makie/44675 "2020-08-14T09:32:19Z")

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I just started using Makie to plot. Is it possible to plot a plane directly from a given function? Eg. I have the following function: y1(y2,y3) = -y2 -y3 - 1.0 I would like to give intervals for y2 and y3 and directly…

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## [Macro scoping issue](https://discourse.julialang.org/t/macro-scoping-issue/44919)

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**Author:** [@jagot](https://discourse.julialang.org/u/jagot)\
**Replies:** 2\
**Last updated:** [August 14, 2020, 8:25am UTC](https://discourse.julialang.org/t/macro-scoping-issue/44919 "2020-08-14T08:25:24Z")

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I have a macro that provides a small DSL and then introduces a variable in the calling scope. I noticed under some circumstances it fails, here is a MWE: macro my\_macro(var, val) :($(esc(var)) = $(val)) end functio…

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## [Computed parametric field types using assertions in \`getproperty\`](https://discourse.julialang.org/t/computed-parametric-field-types-using-assertions-in-getproperty/43865)

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**Author:** [@mhauru](https://discourse.julialang.org/u/mhauru)\
**Replies:** 12\
**Last updated:** [August 14, 2020, 8:14am UTC](https://discourse.julialang.org/t/computed-parametric-field-types-using-assertions-in-getproperty/43865 "2020-08-14T08:14:51Z")

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Quite often I have parametric types where the field types depend in some simple but non-trivial way on the type parameters. Something like struct Dada{N} a::Array{Float64, N} b::Array{Float64, N+1} end The abov…

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## [Slow precompile time with ControlSystems.jl](https://discourse.julialang.org/t/slow-precompile-time-with-controlsystems-jl/44843)

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**Author:** [@cadojo](https://discourse.julialang.org/u/cadojo)\
**Replies:** 11\
**Last updated:** [August 14, 2020, 5:17am UTC](https://discourse.julialang.org/t/slow-precompile-time-with-controlsystems-jl/44843 "2020-08-14T05:17:44Z")

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I’m new to Julia, and I’m excited at the Control Systems design capability! I’m using macOS Catalina on a late 2013 MacBook Pro (2.4 GHz duel-core i5). I understand the initial startup will take longer than subsequent s…

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## [Figure gallery with source code and more](https://discourse.julialang.org/t/figure-gallery-with-source-code-and-more/44911)

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**Author:** [@yoninazarathy](https://discourse.julialang.org/u/yoninazarathy)\
**Replies:** 0\
**Last updated:** [August 14, 2020, 4:34am UTC](https://discourse.julialang.org/t/figure-gallery-with-source-code-and-more/44911 "2020-08-14T04:34:11Z")

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Hi Community, We’ve created a figure gallery presenting the 126 figures that appear in “Statistics with Julia” and are generated by the open sourced code described in the book. This can perhaps be (another) useful quick…

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## [Failed to precompile atom](https://discourse.julialang.org/t/failed-to-precompile-atom/44746)

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**Author:** [@mayar](https://discourse.julialang.org/u/mayar)\
**Replies:** 1\
**Last updated:** [August 14, 2020, 3:55am UTC](https://discourse.julialang.org/t/failed-to-precompile-atom/44746 "2020-08-14T03:55:53Z")

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I was working with Julia on atom and suddenly I go this error message: LoadError: Failed to precompile Atom \[c52e3926-4ff0-5f6e-af25-54175e0327b1\] to C:\\Users\\mayar.madboly\\.julia\\compiled\\v1.4\\Atom\\w9XOh\_U5N9T.ji. W…

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## [How to make JuliaDB writes thread-safe](https://discourse.julialang.org/t/how-to-make-juliadb-writes-thread-safe/44755)

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**Author:** [@mkarikom](https://discourse.julialang.org/u/mkarikom)\
**Replies:** 5\
**Last updated:** [August 14, 2020, 2:06am UTC](https://discourse.julialang.org/t/how-to-make-juliadb-writes-thread-safe/44755 "2020-08-14T02:06:18Z")

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The documentation for JuliaDB doesn’t provide a thread-safe interface for writes. Thus, the code below gives unexpected results. Is there a recommended way to do this? I have a hunch there may be an implementation uti…

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## [Equivalent of MATLAB's unwrap](https://discourse.julialang.org/t/equivalent-of-matlabs-unwrap/44882)

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**Author:** [@wsshin](https://discourse.julialang.org/u/wsshin)\
**Replies:** 6\
**Last updated:** [August 13, 2020, 7:22pm UTC](https://discourse.julialang.org/t/equivalent-of-matlabs-unwrap/44882 "2020-08-13T19:22:22Z")

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Is there a Julia function that is equivalent to MATLAB’s unwrap? It is the function that shift angles by multiples of 2π to make them look distributed continuously.

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## [More upgrade, more slow down?](https://discourse.julialang.org/t/more-upgrade-more-slow-down/44458)

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**Author:** [@paalon](https://discourse.julialang.org/u/paalon)\
**Replies:** 10\
**Last updated:** [August 13, 2020, 10:48pm UTC](https://discourse.julialang.org/t/more-upgrade-more-slow-down/44458 "2020-08-13T22:48:27Z")

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Here is small benchmark code: using BenchmarkTools powersign(i) = ifelse(i % 2 == 0, 1, -1) function leibniz(n) s = 0 for i = 0:n s += powersign(i) / (2i + 1) end 4s end n = 10^5 @benchmark le…

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## [Simultaneous Jacobian and Hessian computations](https://discourse.julialang.org/t/simultaneous-jacobian-and-hessian-computations/44884)

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**Author:** [@mleprovost](https://discourse.julialang.org/u/mleprovost)\
**Replies:** 7\
**Last updated:** [August 13, 2020, 10:15pm UTC](https://discourse.julialang.org/t/simultaneous-jacobian-and-hessian-computations/44884 "2020-08-13T22:15:42Z")

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Hello, I would like to compute the Jacobian and the Hessian of a function f: \\mathbb{R}^n \\xrightarrow{} \\mathbb{R}^m with n,m \\sim60. This function involves multiple Fourier transforms and nonlinear transformations tha…

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## [@time is off by at least 10x](https://discourse.julialang.org/t/time-is-off-by-at-least-10x/44896)

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**Author:** [@mkarikom](https://discourse.julialang.org/u/mkarikom)\
**Replies:** 7\
**Last updated:** [August 13, 2020, 9:53pm UTC](https://discourse.julialang.org/t/time-is-off-by-at-least-10x/44896 "2020-08-13T21:53:11Z")

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f1 calls f2 and f3. (this trivial logic will help with parallelization later) f2 and f3 both mutate struct1 and struct2. function f1!(int1,int2,struct1,struct2) println("\\n running f2: ") @time f2!(int1,struct1,st…

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## [Install IJulia for JupyterHub (multiple-user Jupyter)](https://discourse.julialang.org/t/install-ijulia-for-jupyterhub-multiple-user-jupyter/7432)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 10\
**Last updated:** [August 13, 2020, 8:30pm UTC](https://discourse.julialang.org/t/install-ijulia-for-jupyterhub-multiple-user-jupyter/7432 "2020-08-13T20:30:31Z")

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Hello, I am trying to install a Julia (0.6) kernel for JupyterHub, the multi-user version of Jupyter. I already have JupyterHub working with Python3 and R kernels, I just need to add Julia. I did try (from Julia run as…

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## [How to extract a time series from an image?](https://discourse.julialang.org/t/how-to-extract-a-time-series-from-an-image/44893)

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**Author:** [@VMHidalgo](https://discourse.julialang.org/u/VMHidalgo)\
**Replies:** 5\
**Last updated:** [August 13, 2020, 8:28pm UTC](https://discourse.julialang.org/t/how-to-extract-a-time-series-from-an-image/44893 "2020-08-13T20:28:46Z")

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Hi everybody, I’d like to obtain a time series from the image of a signal. I have a really old paper that includes a Figure from where I need to extract and analyse a 10\[s\] epoch that became gold standard. So I need s…

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## [The birthday paradox: help to be faster than Fortran](https://discourse.julialang.org/t/the-birthday-paradox-help-to-be-faster-than-fortran/44809)

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**Author:** [@profesor\_s](https://discourse.julialang.org/u/profesor_s)\
**Replies:** 16\
**Last updated:** [August 13, 2020, 7:06pm UTC](https://discourse.julialang.org/t/the-birthday-paradox-help-to-be-faster-than-fortran/44809 "2020-08-13T19:06:24Z")

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Introduction I am not able to beat Fortran using Julia. This is the time spent by the algorithm using these two languages: Fortran 0m 42s Julia 4m 33s As you can see, Julia takes 6.5 times the time Fortran takes to s…

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## [Is there a way to find out free disk space equivalent to psutil.disk\_usage('/') in python](https://discourse.julialang.org/t/is-there-a-way-to-find-out-free-disk-space-equivalent-to-psutil-disk-usage-in-python/16918)

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**Author:** [@Ron\_Zaidman](https://discourse.julialang.org/u/Ron_Zaidman)\
**Replies:** 7\
**Last updated:** [August 13, 2020, 6:49pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-find-out-free-disk-space-equivalent-to-psutil-disk-usage-in-python/16918 "2020-08-13T18:49:44Z")

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Is there a way to find out free disk space in drive C: both on windows and linux ? On python I would that by calling psutil.disk\_usage(‘C:’).free

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## [How to add input type to boxplot but remain its plot attribute](https://discourse.julialang.org/t/how-to-add-input-type-to-boxplot-but-remain-its-plot-attribute/44883)

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**Author:** [@1634](https://discourse.julialang.org/u/1634)\
**Replies:** 0\
**Last updated:** [August 13, 2020, 3:50pm UTC](https://discourse.julialang.org/t/how-to-add-input-type-to-boxplot-but-remain-its-plot-attribute/44883 "2020-08-13T15:50:43Z")

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Based on Oheil’s codes (StackOverflowError with boxplot!() due to deprecation - #6 by oheil), I wish to add other optional plot attributes like label, dpi etc. I’ve tried to include them in the input in a primitive way a…

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## [New package: BinaryTreeRectanglePacking.jl (N-dimensions)](https://discourse.julialang.org/t/new-package-binarytreerectanglepacking-jl-n-dimensions/44847)

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**Author:** [@OliverEvans96](https://discourse.julialang.org/u/OliverEvans96)\
**Replies:** 2\
**Last updated:** [August 13, 2020, 3:52pm UTC](https://discourse.julialang.org/t/new-package-binarytreerectanglepacking-jl-n-dimensions/44847 "2020-08-13T15:52:48Z")

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Hi all, I needed to pack lots of rectangles into a larger rectangle for my current project, and found that there wasn’t yet a suitable Julia algorithm, so I wrote one up and I thought I’d share it. I took the algorithm …

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## [StackOverflowError with boxplot!() due to deprecation](https://discourse.julialang.org/t/stackoverflowerror-with-boxplot-due-to-deprecation/44871)

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**Author:** [@1634](https://discourse.julialang.org/u/1634)\
**Replies:** 8\
**Last updated:** [August 13, 2020, 2:28pm UTC](https://discourse.julialang.org/t/stackoverflowerror-with-boxplot-due-to-deprecation/44871 "2020-08-13T14:28:29Z")

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I’d like to have boxplot only considering non-missing data ignoring row informations. using StatsPlots a=\[ 0.000163187 0.000121895 0.000229244 6.98374e-6 missing missing missing missing …

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## [Mmap access denied with SharedArrays](https://discourse.julialang.org/t/mmap-access-denied-with-sharedarrays/44881)

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**Author:** [@mfariacastro](https://discourse.julialang.org/u/mfariacastro)\
**Replies:** 0\
**Last updated:** [August 13, 2020, 3:34pm UTC](https://discourse.julialang.org/t/mmap-access-denied-with-sharedarrays/44881 "2020-08-13T15:34:27Z")

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I am running 1.5.0 on Windows. I keep running into an issue when creating a SharedArray. I am able to replicate the problem about 30% of the time. This is very annoying as it essentially means my code keeps crashing. Thi…

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## [Can't install numpy using Pycall in Ubuntu](https://discourse.julialang.org/t/cant-install-numpy-using-pycall-in-ubuntu/44878)

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**Author:** [@Riya\_Singh](https://discourse.julialang.org/u/Riya_Singh)\
**Replies:** 4\
**Last updated:** [August 13, 2020, 3:14pm UTC](https://discourse.julialang.org/t/cant-install-numpy-using-pycall-in-ubuntu/44878 "2020-08-13T15:14:23Z")

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I can’t seem to understand the problem here can someone please help

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## [Initialising typed array of tuples of ints](https://discourse.julialang.org/t/initialising-typed-array-of-tuples-of-ints/44874)

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**Author:** [@arcadeperfect](https://discourse.julialang.org/u/arcadeperfect)\
**Replies:** 3\
**Last updated:** [August 13, 2020, 2:50pm UTC](https://discourse.julialang.org/t/initialising-typed-array-of-tuples-of-ints/44874 "2020-08-13T14:50:16Z")

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Hi, I’m coming from Python so I’m not too hot on static types. I want an array of tuples of Ints. The number of elements in the array will change depending on the data set used, but the tuples will always be 4 ints. I …

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## [Should I use Val(N) or Val{N}()?](https://discourse.julialang.org/t/should-i-use-val-n-or-val-n/44862)

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**Author:** [@santiagobadia](https://discourse.julialang.org/u/santiagobadia)\
**Replies:** 3\
**Last updated:** [August 13, 2020, 2:28pm UTC](https://discourse.julialang.org/t/should-i-use-val-n-or-val-n/44862 "2020-08-13T14:28:16Z")

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I wanted to ask whether I can safely use Val(N) instead of Val{N}(). In this example @code\_warntype Val(1) @code\_warntype Val{1}() in the REPL I get completely different outputs. The result is inferrable in the seco…

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## [PSA: Julia is not at that stage of development anymore](https://discourse.julialang.org/t/psa-julia-is-not-at-that-stage-of-development-anymore/44872)

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**Author:** [@StefanKarpinski](https://discourse.julialang.org/u/StefanKarpinski)\
**Replies:** 1\
**Last updated:** [August 13, 2020, 1:53pm UTC](https://discourse.julialang.org/t/psa-julia-is-not-at-that-stage-of-development-anymore/44872 "2020-08-13T13:53:20Z")

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You heard about this brand new exciting programming language called Julia and have some suggestions for how it should work. Wonderful! We’re happy to have you here and help you learn the language and listen to your ideas…

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