# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1946

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

**Page:** 1947

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## [Atom REPL cannot display anything](https://discourse.julialang.org/t/atom-repl-cannot-display-anything/27219)

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**Author:** [@Rouzaire](https://discourse.julialang.org/u/Rouzaire)\
**Replies:** 0\
**Last updated:** [August 6, 2019, 2:12pm UTC](https://discourse.julialang.org/t/atom-repl-cannot-display-anything/27219 "2019-08-06T14:12:07Z")

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Hello, I updated julia-client to 0.8.12-beta2 this morning and since then I encountered the following problem : after (and not before) running my (parallelized) code, any entry in the REPL console produces the same out…

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## [Trouble with nested summations in objective funtion](https://discourse.julialang.org/t/trouble-with-nested-summations-in-objective-funtion/27215)

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**Author:** [@Natedogg373](https://discourse.julialang.org/u/Natedogg373)\
**Replies:** 3\
**Last updated:** [August 6, 2019, 1:22pm UTC](https://discourse.julialang.org/t/trouble-with-nested-summations-in-objective-funtion/27215 "2019-08-06T13:22:02Z")

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Hello, I’m a beginner with julia and working on a MIP optimization problem and I’ve been having trouble finishing my objective. Below is the portion of the objective I have traced the error to. sum(sum(3\*t\[i,j,l\]+v1\[i…

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## [Primitive parametric types](https://discourse.julialang.org/t/primitive-parametric-types/27173)

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**Author:** [@hros](https://discourse.julialang.org/u/hros)\
**Replies:** 5\
**Last updated:** [August 6, 2019, 9:12am UTC](https://discourse.julialang.org/t/primitive-parametric-types/27173 "2019-08-06T09:12:23Z")

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Is it possible to specify the bit size of a primitive type as a parameter? If I try: primitive type MyType{B,T,D} \<: Number B end I get : ERROR: invalid declaration of primitive type MyType additionally, I would lik…

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## [Juno crashes over and over again](https://discourse.julialang.org/t/juno-crashes-over-and-over-again/27198)

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**Author:** [@clizama](https://discourse.julialang.org/u/clizama)\
**Replies:** 2\
**Last updated:** [August 6, 2019, 8:33am UTC](https://discourse.julialang.org/t/juno-crashes-over-and-over-again/27198 "2019-08-06T08:33:08Z")

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I’ve been working with Julia 0.6.4 and Julia 1.0.0. When I load a bunch of packages, Atom crashes. I get a message saying “Atom quit unexpectedly”. This happens over and over again. Sometimes I’m able to load more pac…

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## [" Adjusting nev from # to # ". eigs() on a Sparse Array using Arpack](https://discourse.julialang.org/t/adjusting-nev-from-to-eigs-on-a-sparse-array-using-arpack/27163)

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**Author:** [@Adan](https://discourse.julialang.org/u/Adan)\
**Replies:** 3\
**Last updated:** [August 6, 2019, 7:06am UTC](https://discourse.julialang.org/t/adjusting-nev-from-to-eigs-on-a-sparse-array-using-arpack/27163 "2019-08-06T07:06:36Z")

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Hi there! I’m trying to solve an eigenvalues problem. Originally I have a 792x792 matrix that I turned into a Sparse Array. For that purpose I’m using Arpack and eigs( ). The dimension of that array is 792 so I expect t…

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## [How to see the output from DSP.Periodograms.periodogram?](https://discourse.julialang.org/t/how-to-see-the-output-from-dsp-periodograms-periodogram/26732)

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**Author:** [@Andrzej\_Ceglowski](https://discourse.julialang.org/u/Andrzej_Ceglowski)\
**Replies:** 2\
**Last updated:** [August 6, 2019, 2:26am UTC](https://discourse.julialang.org/t/how-to-see-the-output-from-dsp-periodograms-periodogram/26732 "2019-08-06T02:26:23Z")

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Thank you for taking the time to look at my rookie problem. I cannot find documentation on the periodogram type variable and consequently cannot access the results of DSP periodograms routine. Can you help? The steps/d…

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## [How can I solve "no method matching Chains" in Turing - Julia](https://discourse.julialang.org/t/how-can-i-solve-no-method-matching-chains-in-turing-julia/27166)

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**Author:** [@Manu\_Francis](https://discourse.julialang.org/u/Manu_Francis)\
**Replies:** 4\
**Last updated:** [August 6, 2019, 1:27am UTC](https://discourse.julialang.org/t/how-can-i-solve-no-method-matching-chains-in-turing-julia/27166 "2019-08-06T01:27:03Z")

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Hi, I am trying to learn as a beginner of Julia and Turing and run the following program given in Turing tutorial. # Import libraries. using Turing, StatsPlots, Random # Set the true probability of heads in a coin. p\_…

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## [JuliaCon 2019 | What's Bad About Julia](https://discourse.julialang.org/t/juliacon-2019-whats-bad-about-julia/27177)

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**Author:** [@o314](https://discourse.julialang.org/u/o314)\
**Replies:** 2\
**Last updated:** [August 5, 2019, 11:47pm UTC](https://discourse.julialang.org/t/juliacon-2019-whats-bad-about-julia/27177 "2019-08-05T23:47:49Z")

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3:42 Sorry to say i was unable to understand the name of the person with whom Jeff Bezanson had a good chat about the future protocol system. Best guess starting here - Jiahao Chen, Keno Fischer, Matt Bauma…

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## [\`inmin\` and \`inmax\` not defined](https://discourse.julialang.org/t/inmin-and-inmax-not-defined/27175)

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**Author:** [@ryanorsinger](https://discourse.julialang.org/u/ryanorsinger)\
**Replies:** 5\
**Last updated:** [August 5, 2019, 11:31pm UTC](https://discourse.julialang.org/t/inmin-and-inmax-not-defined/27175 "2019-08-05T23:31:16Z")

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Good day! I’m working though “Julia for Data Science” by Voulgaris, and in Chapter 2, the global functions inmin and inmax are not defined. Because the book is written in Julia 0.4. I searched https://docs.julialang.org…

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## [Making VulkanCore.jl work with latest version of Julia](https://discourse.julialang.org/t/making-vulkancore-jl-work-with-latest-version-of-julia/27108)

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**Author:** [@rapasite](https://discourse.julialang.org/u/rapasite)\
**Replies:** 5\
**Last updated:** [August 5, 2019, 7:43pm UTC](https://discourse.julialang.org/t/making-vulkancore-jl-work-with-latest-version-of-julia/27108 "2019-08-05T19:43:07Z")

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ERROR: Unsatisfiable requirements detected for package VulkanCore \[16167f82\]: VulkanCore \[16167f82\] log: ├─possible versions are: 1.0.0 or uninstalled ├─restricted to versions \* by an explicit requirement, leaving onl…

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## [Decade anniversary coming up!](https://discourse.julialang.org/t/decade-anniversary-coming-up/27186)

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**Author:** [@bjarthur](https://discourse.julialang.org/u/bjarthur)\
**Replies:** 0\
**Last updated:** [August 5, 2019, 7:36pm UTC](https://discourse.julialang.org/t/decade-anniversary-coming-up/27186 "2019-08-05T19:36:24Z")

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commit a9cbc036ac62dc5ba5200416ca7b40a2f9aa59ea Author: Stefan Karpinski \<stefan.karpinski@gmail.com\> Date: Sat Aug 22 20:39:06 2009 -0700 Initial empty commit. is there a party planned?

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## [Query.jl - Return all columns with @map](https://discourse.julialang.org/t/query-jl-return-all-columns-with-map/11717)

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**Author:** [@joshualeond](https://discourse.julialang.org/u/joshualeond)\
**Replies:** 3\
**Last updated:** [August 5, 2019, 7:13pm UTC](https://discourse.julialang.org/t/query-jl-return-all-columns-with-map/11717 "2019-08-05T19:13:45Z")

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Hey there, I recently watched @davidanthoff’s Queryverse tutorial and am giving Query.jl a go. I like the new pipe-able syntax as I’m a heavy user of dplyr. I see the @map macro would be similar to the select and mutate …

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## [PGFPlotsX.jl - custom color cycler?](https://discourse.julialang.org/t/pgfplotsx-jl-custom-color-cycler/27178)

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**Author:** [@tamasgal](https://discourse.julialang.org/u/tamasgal)\
**Replies:** 8\
**Last updated:** [August 5, 2019, 3:47pm UTC](https://discourse.julialang.org/t/pgfplotsx-jl-custom-color-cycler/27178 "2019-08-05T15:47:54Z")

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I am trying to use a custom color cycler for all my plots in my thesis. In my LaTeX style document I defined some colours for testing, here is an example which I found on SO: \\usepackage{pgfplots} \\definecolor{blues1}{…

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## [Cannot install packages on Julia version 1.1.1 due to certificate validation failure](https://discourse.julialang.org/t/cannot-install-packages-on-julia-version-1-1-1-due-to-certificate-validation-failure/26973)

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**Author:** [@R366Y](https://discourse.julialang.org/u/R366Y)\
**Replies:** 2\
**Last updated:** [August 5, 2019, 11:24am UTC](https://discourse.julialang.org/t/cannot-install-packages-on-julia-version-1-1-1-due-to-certificate-validation-failure/26973 "2019-08-05T11:24:11Z")

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Hi , I’m new to Julia development and I’m trying to make some small programs in order to learn the language but I cannot install any package due to the error you can see below. I’m at work and I use several IDE like In…

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## [Calculate SVM dual loss effeciently](https://discourse.julialang.org/t/calculate-svm-dual-loss-effeciently/27171)

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**Author:** [@Charlie\_He](https://discourse.julialang.org/u/Charlie_He)\
**Replies:** 0\
**Last updated:** [August 5, 2019, 10:12am UTC](https://discourse.julialang.org/t/calculate-svm-dual-loss-effeciently/27171 "2019-08-05T10:12:30Z")

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I am trying to implement a SVM dual optimization problem in Julia. My data set is the 60000x784 MNIST number recognition dataset. Here are my functions for The linear version is very fast: function dual\_loss(α::Vec, X:…

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## [Checking the uniqueness of a tuple](https://discourse.julialang.org/t/checking-the-uniqueness-of-a-tuple/27161)

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**Author:** [@affans](https://discourse.julialang.org/u/affans)\
**Replies:** 3\
**Last updated:** [August 5, 2019, 9:55am UTC](https://discourse.julialang.org/t/checking-the-uniqueness-of-a-tuple/27161 "2019-08-05T09:55:00Z")

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I have an array of tuples, i.e. Array{Tuple{Int64, Int64}} which I would like to filter by unique items. That is, my uniqueness criteria for a tuple is that (x\_1, x\_2) = (x\_2, x\_1). So if I have a = \[(1, 2), (3, 4), (…

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## [IndexedTable to DataFrame](https://discourse.julialang.org/t/indexedtable-to-dataframe/26528)

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**Author:** [@bernhard](https://discourse.julialang.org/u/bernhard)\
**Replies:** 3\
**Last updated:** [August 5, 2019, 8:17am UTC](https://discourse.julialang.org/t/indexedtable-to-dataframe/26528 "2019-08-05T08:17:32Z")

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I am wondering how to convert an IndexedTable to a DataFrame. There are two posts that offer (partial) solutions to this, but I am not sure if that is (still) the best way. For now, it is not clear to me when it is pr…

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## [How to implement the Python's \`itertools.tee\` function](https://discourse.julialang.org/t/how-to-implement-the-pythons-itertools-tee-function/27142)

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**Author:** [@singularitti](https://discourse.julialang.org/u/singularitti)\
**Replies:** 3\
**Last updated:** [August 5, 2019, 12:37am UTC](https://discourse.julialang.org/t/how-to-implement-the-pythons-itertools-tee-function/27142 "2019-08-05T00:37:39Z")

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Python’s doc has given a roughly equivalent to its itertools.tee function: def tee(iterable, n=2): it = iter(iterable) deques = \[collections.deque() for i in range(n)\] def gen(mydeque): while True: …

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## [How to modify value of \*scalar\* argument passed to function so that it persists in calling function?](https://discourse.julialang.org/t/how-to-modify-value-of-scalar-argument-passed-to-function-so-that-it-persists-in-calling-function/27151)

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**Author:** [@Rafal\_Machalica](https://discourse.julialang.org/u/Rafal_Machalica)\
**Replies:** 8\
**Last updated:** [August 4, 2019, 11:31pm UTC](https://discourse.julialang.org/t/how-to-modify-value-of-scalar-argument-passed-to-function-so-that-it-persists-in-calling-function/27151 "2019-08-04T23:31:59Z")

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I want to obtain standard C behaviour of following minimal example: int a = 5; void f (int \*a) { \*a = \*a+1; } f(&a); after calling the function, variable “a” will still be equal 6 in outer scope. I am aware that i…

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## [How to use SparseArrays single precision (Float32)?](https://discourse.julialang.org/t/how-to-use-sparsearrays-single-precision-float32/27150)

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**Author:** [@Jorge\_Vieyra](https://discourse.julialang.org/u/Jorge_Vieyra)\
**Replies:** 2\
**Last updated:** [August 4, 2019, 11:19pm UTC](https://discourse.julialang.org/t/how-to-use-sparsearrays-single-precision-float32/27150 "2019-08-04T23:19:11Z")

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Hi All, I was just experimenting with a Float32 matrix because I want to see if it’s faster and with enough precision. However to my surprise, I realized that this is not doing what I am expecting: backslash '' (ldiv…

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## [Support with embedding julia in C++](https://discourse.julialang.org/t/support-with-embedding-julia-in-c/5054)

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**Author:** [@yogi](https://discourse.julialang.org/u/yogi)\
**Replies:** 12\
**Last updated:** [August 4, 2019, 10:46pm UTC](https://discourse.julialang.org/t/support-with-embedding-julia-in-c/5054 "2019-08-04T22:46:02Z")

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We are embedding julia in C++. The first few calls to the function are completed successfully, but after a few times the following error comes up. while loading no file, in expression starting on line 389 jl\_subtype\_le…

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## [Unexpected 4x slowdown when computing many svds in loop](https://discourse.julialang.org/t/unexpected-4x-slowdown-when-computing-many-svds-in-loop/27148)

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**Author:** [@egcjm](https://discourse.julialang.org/u/egcjm)\
**Replies:** 4\
**Last updated:** [August 4, 2019, 4:01pm UTC](https://discourse.julialang.org/t/unexpected-4x-slowdown-when-computing-many-svds-in-loop/27148 "2019-08-04T16:01:06Z")

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I compute svds of N roughly ~100x100 matrices and note a 4x slowdown when I do this in a loop for N \> 100. function f\_svd(n::Int64,a::Array{Float64,2}) for i in 1:n u,s,v = svd(a); end end (in my r…

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## [Start up costs when using remotecall\_fetch](https://discourse.julialang.org/t/start-up-costs-when-using-remotecall-fetch/27072)

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**Author:** [@DanielAvilaGirardot](https://discourse.julialang.org/u/DanielAvilaGirardot)\
**Replies:** 2\
**Last updated:** [August 4, 2019, 2:21pm UTC](https://discourse.julialang.org/t/start-up-costs-when-using-remotecall-fetch/27072 "2019-08-04T14:21:51Z")

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Hello, Is there a measure of the start up costs when using functions such as pmap or remotecall\_fetch?. By start up cost I mean the time elapsed from the instant in which the remotecall\_fetch command is called and the i…

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## [Handling multipart/form-data with Mux or HTTP](https://discourse.julialang.org/t/handling-multipart-form-data-with-mux-or-http/24918)

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**Author:** [@tencnivel](https://discourse.julialang.org/u/tencnivel)\
**Replies:** 3\
**Last updated:** [August 4, 2019, 1:48pm UTC](https://discourse.julialang.org/t/handling-multipart-form-data-with-mux-or-http/24918 "2019-08-04T13:48:21Z")

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Hi everyone! I’m trying to handle the upload of files (several files at the same time) using Mux. I would like to be able to loop over the input parts and for each of them : get the name of the file get the content of…

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## [JuliaCon 2019 streaming live](https://discourse.julialang.org/t/juliacon-2019-streaming-live/26684)

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**Author:** [@viralbshah](https://discourse.julialang.org/u/viralbshah)\
**Replies:** 19\
**Last updated:** [August 4, 2019, 1:30pm UTC](https://discourse.julialang.org/t/juliacon-2019-streaming-live/26684 "2019-08-04T13:30:36Z")

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JuliaCon 2019 is streaming live on the Julia Channel on Youtube. Every video has its own livestream and will be linked on the channel page as it goes live.

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## [Reusing variable in multiple parallel calls](https://discourse.julialang.org/t/reusing-variable-in-multiple-parallel-calls/23187)

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**Author:** [@dsweber2](https://discourse.julialang.org/u/dsweber2)\
**Replies:** 5\
**Last updated:** [August 4, 2019, 11:48am UTC](https://discourse.julialang.org/t/reusing-variable-in-multiple-parallel-calls/23187 "2019-08-04T11:48:35Z")

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I am going to be calling the same fft on several remote workers many times each. To get an additional speed improvement, I am aiming to use plan\_fft. But plan\_fft objects aren’t thread safe, so I can’t reuse the same pla…

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## [Do you need to run function (from compiled module) twice to get performance benefit in Julia script?](https://discourse.julialang.org/t/do-you-need-to-run-function-from-compiled-module-twice-to-get-performance-benefit-in-julia-script/27147)

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**Author:** [@Donut\_Meepo](https://discourse.julialang.org/u/Donut_Meepo)\
**Replies:** 3\
**Last updated:** [August 4, 2019, 7:48am UTC](https://discourse.julialang.org/t/do-you-need-to-run-function-from-compiled-module-twice-to-get-performance-benefit-in-julia-script/27147 "2019-08-04T07:48:29Z")

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Hi, I am writing a module with couple functions to be used in a script. If I run the script that using functions from the precompiled module, do I still need to include a small dataset to compile the functions? Here mig…

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## [Sending Dataframes of different lengths to a CSV file](https://discourse.julialang.org/t/sending-dataframes-of-different-lengths-to-a-csv-file/27064)

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**Author:** [@MuadhF](https://discourse.julialang.org/u/MuadhF)\
**Replies:** 3\
**Last updated:** [August 4, 2019, 6:53am UTC](https://discourse.julialang.org/t/sending-dataframes-of-different-lengths-to-a-csv-file/27064 "2019-08-04T06:53:02Z")

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Hi, Is there a way to send DataFrames of different lengths to a CSV file, so that when I open them in Excel, they would appear side by side? Or is there simply a way to create a single DataFrame with varying column len…

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## [Generated Code needs 2 scopes! module level scope and current scope](https://discourse.julialang.org/t/generated-code-needs-2-scopes-module-level-scope-and-current-scope/27125)

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**Author:** [@Qiyamah](https://discourse.julialang.org/u/Qiyamah)\
**Replies:** 2\
**Last updated:** [August 4, 2019, 2:13am UTC](https://discourse.julialang.org/t/generated-code-needs-2-scopes-module-level-scope-and-current-scope/27125 "2019-08-04T02:13:15Z")

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macro instantiate(typ) quote struct $typ end $typ() end |\> esc end tt = @instantiate(TT) # this is ok julia\> f(x) = begin @instantiate NN …

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## [Is the "isbits union" optimization enabled in Julia 1.1?](https://discourse.julialang.org/t/is-the-isbits-union-optimization-enabled-in-julia-1-1/27130)

<div class="topic-metadata">

**Author:** [@jonathan-laurent](https://discourse.julialang.org/u/jonathan-laurent)\
**Replies:** 6\
**Last updated:** [August 4, 2019, 2:10am UTC](https://discourse.julialang.org/t/is-the-isbits-union-optimization-enabled-in-julia-1-1/27130 "2019-08-04T02:10:15Z")

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According to the documentation, the so-called “isbits Union optimization” should apply to the following type definition: struct S x :: Union{UInt8, Int16} end Therefore, I would expect isbitstype(S) to be true. Howev…

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