# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1955

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

**Page:** 1956

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## [How to remove rows containing missing from DataFrame?](https://discourse.julialang.org/t/how-to-remove-rows-containing-missing-from-dataframe/12234)

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**Author:** [@Gyslain](https://discourse.julialang.org/u/Gyslain)\
**Replies:** 6\
**Last updated:** [July 22, 2019, 10:07pm UTC](https://discourse.julialang.org/t/how-to-remove-rows-containing-missing-from-dataframe/12234 "2019-07-22T22:07:01Z")

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Hi, given this DataFrame : A=DataFrame(a=\[1:2;missing;4\], b=1:4) 4×2 DataFrames.DataFrame │ Row │ a │ b │ ├─────┼─────────┼───┤ │ 1 │ 1 │ 1 │ │ 2 │ 2 │ 2 │ │ 3 │ missing │ 3 │ │ 4 │ 4 │ 4…

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## [Copying variable to all remote processes?](https://discourse.julialang.org/t/copying-variable-to-all-remote-processes/26518)

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**Author:** [@vlandau](https://discourse.julialang.org/u/vlandau)\
**Replies:** 5\
**Last updated:** [July 19, 2019, 4:18pm UTC](https://discourse.julialang.org/t/copying-variable-to-all-remote-processes/26518 "2019-07-19T16:18:16Z")

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Hello all, I’m working on some code where each remote worker needs to compute an array by accumulating values, and the arrays then need to be summed. Below is an absolute minimum working example to demonstrate the probl…

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## [Composite types versus lookup tables](https://discourse.julialang.org/t/composite-types-versus-lookup-tables/26534)

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**Author:** [@yakir12](https://discourse.julialang.org/u/yakir12)\
**Replies:** 7\
**Last updated:** [July 22, 2019, 6:03pm UTC](https://discourse.julialang.org/t/composite-types-versus-lookup-tables/26534 "2019-07-22T18:03:47Z")

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I’ve been fluctuating between holding my data in database-style tables versus composite types. Things like joining in the DB version is very useful, but things tend to stay as floats and strings. Method dispatch and cus…

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## [How to initialize two dimensional array of arrays?](https://discourse.julialang.org/t/how-to-initialize-two-dimensional-array-of-arrays/26635)

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**Author:** [@mike\_k](https://discourse.julialang.org/u/mike_k)\
**Replies:** 5\
**Last updated:** [July 22, 2019, 4:25pm UTC](https://discourse.julialang.org/t/how-to-initialize-two-dimensional-array-of-arrays/26635 "2019-07-22T16:25:44Z")

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Dear community, I fail to initialize an array of type Array{Array{UInt16,1},2}. In particular I tried it via a mutable struct, which in my case then leads to type Array{Array{UInt16,N} where N,2} which I can use as want…

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## [Is the following code using some regression technique?](https://discourse.julialang.org/t/is-the-following-code-using-some-regression-technique/26636)

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**Author:** [@bsnyh](https://discourse.julialang.org/u/bsnyh)\
**Replies:** 1\
**Last updated:** [July 22, 2019, 3:57pm UTC](https://discourse.julialang.org/t/is-the-following-code-using-some-regression-technique/26636 "2019-07-22T15:57:32Z")

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The following piece of code is from the OpenStreetMapX package. The logic is pretty straightforward to follow. I was just wondering, where is the constant 3.6 from? Does it come from some statistical fittings? Any commen…

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## [Split an Int128 to two Int64](https://discourse.julialang.org/t/split-an-int128-to-two-int64/26625)

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**Author:** [@hros](https://discourse.julialang.org/u/hros)\
**Replies:** 2\
**Last updated:** [July 22, 2019, 12:31pm UTC](https://discourse.julialang.org/t/split-an-int128-to-two-int64/26625 "2019-07-22T12:31:46Z")

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Edit: this post started as a question and as a I found an answer turned into a suggestion to update the documentation I have to multiply two Int64 values and split the result into the high and low 64 bit values. This i…

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## [How to filter out missings (using DataFramesMeta @where)](https://discourse.julialang.org/t/how-to-filter-out-missings-using-dataframesmeta-where/26618)

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**Author:** [@abeburnett](https://discourse.julialang.org/u/abeburnett)\
**Replies:** 2\
**Last updated:** [July 22, 2019, 11:43am UTC](https://discourse.julialang.org/t/how-to-filter-out-missings-using-dataframesmeta-where/26618 "2019-07-22T11:43:52Z")

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How do I filter out missings when working with DataFramesMeta? For context, my background is R/Python, and in R I use the tidyverse/dplyr/etc. heavily. I want to do: @linq indeed\_dice\_data |\> transform(mean\_subdoma…

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## [Nested parallel loop](https://discourse.julialang.org/t/nested-parallel-loop/26623)

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**Author:** [@bernhard](https://discourse.julialang.org/u/bernhard)\
**Replies:** 4\
**Last updated:** [July 22, 2019, 10:34am UTC](https://discourse.julialang.org/t/nested-parallel-loop/26623 "2019-07-22T10:34:34Z")

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Is there an easy way, to make the example below work? using Distributed addprocs(3) @sync @distributed (+) for x in collect(1:10), y in collect(1:10) sum(rand(x,y)) end

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## [Makie interaction: Slider with animation](https://discourse.julialang.org/t/makie-interaction-slider-with-animation/25179)

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**Author:** [@neuralian](https://discourse.julialang.org/u/neuralian)\
**Replies:** 10\
**Last updated:** [July 22, 2019, 10:12am UTC](https://discourse.julialang.org/t/makie-interaction-slider-with-animation/25179 "2019-07-22T10:12:19Z")

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(Edited for clarity in the light of feedback (thanks, yakir12) about how to post on this forum) I’m struggling to figure out how to use a slider to interact with an animation in Makie. I’m using v1.1.1 in Atom under W…

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## [Problem with Pkg: cannot be found in current path](https://discourse.julialang.org/t/problem-with-pkg-cannot-be-found-in-current-path/26492)

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**Author:** [@pjgorski](https://discourse.julialang.org/u/pjgorski)\
**Replies:** 3\
**Last updated:** [July 22, 2019, 8:22am UTC](https://discourse.julialang.org/t/problem-with-pkg-cannot-be-found-in-current-path/26492 "2019-07-22T08:22:54Z")

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Hi! I am working on Julia 1.0.3. I am using Atom in Ubuntu 16. Today I upgraded Atom and julia-client packages and after it Julia repl cannot start. Following error message is displayed: Hold on tight while we are insta…

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## [Julia and Demography](https://discourse.julialang.org/t/julia-and-demography/23773)

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**Author:** [@sbacelar](https://discourse.julialang.org/u/sbacelar)\
**Replies:** 9\
**Last updated:** [July 22, 2019, 7:16am UTC](https://discourse.julialang.org/t/julia-and-demography/23773 "2019-07-22T07:16:54Z")

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Is there any work on (computational) demography using Julia?

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## [ErrorException("Task cannot be serialized") with TaskWrapper struct](https://discourse.julialang.org/t/errorexception-task-cannot-be-serialized-with-taskwrapper-struct/26617)

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**Author:** [@Jasha10](https://discourse.julialang.org/u/Jasha10)\
**Replies:** 3\
**Last updated:** [July 22, 2019, 3:39am UTC](https://discourse.julialang.org/t/errorexception-task-cannot-be-serialized-with-taskwrapper-struct/26617 "2019-07-22T03:39:49Z")

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I’ve got a TaskWrappers.jl package whose source file looks like this. module TaskWrappers struct TaskWrapper task::Task end t = @async sleep(10) example = TaskWrapper(t) end My directory layout is simple: |- Proje…

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## [Parameter tuning in neural ODE](https://discourse.julialang.org/t/parameter-tuning-in-neural-ode/26450)

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**Author:** [@JunichiFukui](https://discourse.julialang.org/u/JunichiFukui)\
**Replies:** 15\
**Last updated:** [July 21, 2019, 10:03pm UTC](https://discourse.julialang.org/t/parameter-tuning-in-neural-ode/26450 "2019-07-21T22:03:10Z")

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Hello, I’m trying to reproduce chemical reaction equations using neural ODE system. I calculated time-series of mass fraction of chemical species and temperature using other ODE solver, and exported the solution data to…

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## [Include command inconsistent with isfile result](https://discourse.julialang.org/t/include-command-inconsistent-with-isfile-result/26578)

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**Author:** [@bernhard](https://discourse.julialang.org/u/bernhard)\
**Replies:** 17\
**Last updated:** [July 21, 2019, 8:26pm UTC](https://discourse.julialang.org/t/include-command-inconsistent-with-isfile-result/26578 "2019-07-21T20:26:52Z")

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I am having trouble to include a file. More precisely isfile(fi) returns true, but include(fi) errors ERROR: LoadError: could not open file C:\\temp\\a\\SomePackage\\src\\src\\file.jl I created an MWE here. I simply run jul…

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## [DiffEqFlux with time as additional input to Neural ODE](https://discourse.julialang.org/t/diffeqflux-with-time-as-additional-input-to-neural-ode/26456)

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**Author:** [@Michael\_Struwig](https://discourse.julialang.org/u/Michael_Struwig)\
**Replies:** 7\
**Last updated:** [July 21, 2019, 3:41pm UTC](https://discourse.julialang.org/t/diffeqflux-with-time-as-additional-input-to-neural-ode/26456 "2019-07-21T15:41:17Z")

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Hi! My academic or theoretical vocabulary isn’t extensive, so please excuse any lack of terminology on my part. Please point the correct terminology out to me, I’m more than happy to learn. I’ve been enjoying and follo…

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## [How to bin data properly for further study, by example to plot it estimated PDf and CDF?](https://discourse.julialang.org/t/how-to-bin-data-properly-for-further-study-by-example-to-plot-it-estimated-pdf-and-cdf/26511)

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**Author:** [@Masacroso](https://discourse.julialang.org/u/Masacroso)\
**Replies:** 12\
**Last updated:** [July 21, 2019, 3:02pm UTC](https://discourse.julialang.org/t/how-to-bin-data-properly-for-further-study-by-example-to-plot-it-estimated-pdf-and-cdf/26511 "2019-07-21T15:02:49Z")

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I didn’t found a package to bin data such that I can use the binned data for further analysis, just I found some bin functions inside plotting functions, by example to plot histograms or so, but I want just the binned da…

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## [Error with ode\_def](https://discourse.julialang.org/t/error-with-ode-def/18594)

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**Author:** [@Stephen](https://discourse.julialang.org/u/Stephen)\
**Replies:** 16\
**Last updated:** [July 21, 2019, 12:10pm UTC](https://discourse.julialang.org/t/error-with-ode-def/18594 "2019-07-21T12:10:46Z")

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using DifferentialEquations f = @ode\_def LotkaVolterra begin dx = a\*x - b\*x\*y dy = -c\*y + d\*x\*y end a b c d produce ERROR: LoadError: LoadError: error compiling #ode\_def\_opts#1: error compiling symbols: error compi…

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## [How to feed initial solution to solver?](https://discourse.julialang.org/t/how-to-feed-initial-solution-to-solver/26577)

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**Author:** [@Qun](https://discourse.julialang.org/u/Qun)\
**Replies:** 2\
**Last updated:** [July 21, 2019, 12:08pm UTC](https://discourse.julialang.org/t/how-to-feed-initial-solution-to-solver/26577 "2019-07-21T12:08:20Z")

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I am keen to learn how to feed an initial solution to a solver. I use the following example and I got the above warning when I used CPLEX, Cbc, Gurobi, GLPK. Could any one point me in the right direction to solve this is…

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## [Extremely long compilation time (\> 2000 sec on Win32)](https://discourse.julialang.org/t/extremely-long-compilation-time-2000-sec-on-win32/26496)

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**Author:** [@devmotion](https://discourse.julialang.org/u/devmotion)\
**Replies:** 13\
**Last updated:** [July 21, 2019, 10:19am UTC](https://discourse.julialang.org/t/extremely-long-compilation-time-2000-sec-on-win32/26496 "2019-07-21T10:19:48Z")

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Hej! I’m observing extremely long compilation times of more than 2000 sec on Appveyor (Win32) for the delay differential equation solver package DelayDiffEq. A week ago, with version 5.7.0 the first test took around 16…

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## [How can I make a package run in its own environment](https://discourse.julialang.org/t/how-can-i-make-a-package-run-in-its-own-environment/26601)

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**Author:** [@Chong\_Wang](https://discourse.julialang.org/u/Chong_Wang)\
**Replies:** 5\
**Last updated:** [July 21, 2019, 8:13am UTC](https://discourse.julialang.org/t/how-can-i-make-a-package-run-in-its-own-environment/26601 "2019-07-21T08:13:53Z")

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If I create a package Foo depending on Bar@0.1.0, and the default environment (say, v1.1) has Bar@0.2.0, how can I use the package Foo in the default environment? Here’s what I did: In the environment Foo, I \]add Bar@…

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## [New behaviour due to an update of the package CSV when using CSV.read](https://discourse.julialang.org/t/new-behaviour-due-to-an-update-of-the-package-csv-when-using-csv-read/26565)

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**Author:** [@steph\_de\_paris](https://discourse.julialang.org/u/steph_de_paris)\
**Replies:** 5\
**Last updated:** [July 21, 2019, 7:49am UTC](https://discourse.julialang.org/t/new-behaviour-due-to-an-update-of-the-package-csv-when-using-csv-read/26565 "2019-07-21T07:49:51Z")

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Hello, When the file tmp.csv just contains the string “INFI\_”, the code using CSV data = CSV.read("tmp.csv",header=false,delim=';'); data gives the result 1×1 DataFrames.DataFrame │ Row │ Column1 │ │ │ String …

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## [Philosophy on asserts](https://discourse.julialang.org/t/philosophy-on-asserts/26587)

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**Author:** [@lewis](https://discourse.julialang.org/u/lewis)\
**Replies:** 5\
**Last updated:** [July 21, 2019, 5:54am UTC](https://discourse.julialang.org/t/philosophy-on-asserts/26587 "2019-07-21T05:54:45Z")

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Curious what the view on asserts in released, production code is. Working on PR for Pkg.TOML. It has lots of places that trigger assert error on nothing values with a get method: get(x) = (@assert !isnull(x); x). In t…

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## [What is the main purpose of this hash function in the following code?](https://discourse.julialang.org/t/what-is-the-main-purpose-of-this-hash-function-in-the-following-code/26586)

<div class="topic-metadata">

**Author:** [@bsnyh](https://discourse.julialang.org/u/bsnyh)\
**Replies:** 2\
**Last updated:** [July 21, 2019, 5:33am UTC](https://discourse.julialang.org/t/what-is-the-main-purpose-of-this-hash-function-in-the-following-code/26586 "2019-07-21T05:33:29Z")

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The following is the code, excerpted from OpenStreetMapX package. I do not quite understand what is the purpose of the hash function here? Based on the help of the hash function from REPL, the hash function hash(x\[, h::U…

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## [Row and column with multiple plots in VegaLite.jl](https://discourse.julialang.org/t/row-and-column-with-multiple-plots-in-vegalite-jl/26426)

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**Author:** [@yanivab](https://discourse.julialang.org/u/yanivab)\
**Replies:** 1\
**Last updated:** [July 20, 2019, 10:03pm UTC](https://discourse.julialang.org/t/row-and-column-with-multiple-plots-in-vegalite-jl/26426 "2019-07-20T22:03:10Z")

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Trying to make a plot with a line and error band, and subplots in rows and columns. However, when I try this: dat |\> @vlplot(row = "sess:o", column = "PID:n") + @vlplot(:errorband, y = "rand\_lb:q", y2 = "rand\_ub:q", x =…

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## [Pass struct with mutable array field to ccall?](https://discourse.julialang.org/t/pass-struct-with-mutable-array-field-to-ccall/26576)

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**Author:** [@tuckermcclure](https://discourse.julialang.org/u/tuckermcclure)\
**Replies:** 7\
**Last updated:** [July 20, 2019, 10:01pm UTC](https://discourse.julialang.org/t/pass-struct-with-mutable-array-field-to-ccall/26576 "2019-07-20T22:01:55Z")

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I need to call a C interface that has a struct argument like so: typedef struct { double a\[2\]; } MyStruct; I know I can could use the following Julia type to represent my data and pass that to ccall: mutable struc…

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## [Pharmaceutical Modeling and Simulation with Pumas](https://discourse.julialang.org/t/pharmaceutical-modeling-and-simulation-with-pumas/26556)

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**Author:** [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Replies:** 4\
**Last updated:** [July 20, 2019, 9:50pm UTC](https://discourse.julialang.org/t/pharmaceutical-modeling-and-simulation-with-pumas/26556 "2019-07-20T21:50:16Z")

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We are excited to announce Pumas.jl, a package for pharmaceutical modeling and simulation. The website for the project can be found at https://pumas.ai . With Pumas you can easily simulate and fit nonlinear mixed effects…

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## [InexactError while using the PiGPIO.jl package from JuliaBerry](https://discourse.julialang.org/t/inexacterror-while-using-the-pigpio-jl-package-from-juliaberry/26593)

<div class="topic-metadata">

**Author:** [@akshayh](https://discourse.julialang.org/u/akshayh)\
**Replies:** 1\
**Last updated:** [July 20, 2019, 9:37pm UTC](https://discourse.julialang.org/t/inexacterror-while-using-the-pigpio-jl-package-from-juliaberry/26593 "2019-07-20T21:37:20Z")

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Hi, I am trying to read sensor (MPU 6050) data using Raspberry Pi 3 and Julia using the PiGPIO package. I have connected my Pi to the pigpio daemon over a network. When I am trying to use “i2c\_write\_byte” function some…

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## [@async calls to WebSockets read and write methods](https://discourse.julialang.org/t/async-calls-to-websockets-read-and-write-methods/26405)

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**Author:** [@Jasha10](https://discourse.julialang.org/u/Jasha10)\
**Replies:** 6\
**Last updated:** [July 20, 2019, 8:09pm UTC](https://discourse.julialang.org/t/async-calls-to-websockets-read-and-write-methods/26405 "2019-07-20T20:09:22Z")

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I’ve put together a simple coroutine that makes use of the WebSockets.jl package, but I’m not sure if WebSockets.jl (or the underlying HTTP.jl) is designed to be able to handle this sort of asynchronous behavior: using …

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## [What is the relation between Array{Int64,1} and AbstractSet{Int64}?](https://discourse.julialang.org/t/what-is-the-relation-between-array-int64-1-and-abstractset-int64/26590)

<div class="topic-metadata">

**Author:** [@bsnyh](https://discourse.julialang.org/u/bsnyh)\
**Replies:** 1\
**Last updated:** [July 20, 2019, 5:19pm UTC](https://discourse.julialang.org/t/what-is-the-relation-between-array-int64-1-and-abstractset-int64/26590 "2019-07-20T17:19:10Z")

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Hi, the following is the code, which confuses me. function myF( a::AbstractSet{Int} ) for element in a print(element) end end b = Dict( 1 =\> 2, 2 =\> 3, 3 =\>4 ) myF(collec…

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## [Announcing Maxima.jl](https://discourse.julialang.org/t/announcing-maxima-jl/3013)

<div class="topic-metadata">

**Author:** [@nsmith](https://discourse.julialang.org/u/nsmith)\
**Replies:** 4\
**Last updated:** [April 6, 2017, 1:35pm UTC](https://discourse.julialang.org/t/announcing-maxima-jl/3013 "2017-04-06T13:35:12Z")

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I’d like to announce here for the first time the availability of Maxima.jl. A symbolic mathematics package for julia that uses the Maxima CAS. Maxima features: a full Maxima REPL mode that can be extends the Julia REPL …

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