# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1980

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

**Page:** 1981

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## [Worker Proc Failing to Iterate JuliaDB Table](https://discourse.julialang.org/t/worker-proc-failing-to-iterate-juliadb-table/25046)

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**Author:** [@dburch](https://discourse.julialang.org/u/dburch)\
**Replies:** 1\
**Last updated:** [June 11, 2019, 5:17pm UTC](https://discourse.julialang.org/t/worker-proc-failing-to-iterate-juliadb-table/25046 "2019-06-11T17:17:49Z")

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I am getting an error when I try to iterate through a table on worker 2. I can open the table on worker 2 and println the table, but iteration which I can normally do in a serial process is failing. It errors on line 25:…

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## [How to convert a string that contains timezone to DateTime?](https://discourse.julialang.org/t/how-to-convert-a-string-that-contains-timezone-to-datetime/25120)

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**Author:** [@jayce\_ram](https://discourse.julialang.org/u/jayce_ram)\
**Replies:** 3\
**Last updated:** [June 11, 2019, 4:05pm UTC](https://discourse.julialang.org/t/how-to-convert-a-string-that-contains-timezone-to-datetime/25120 "2019-06-11T16:05:31Z")

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I have a huge csv file (\>60 millions of lines) that contains a column with date time associated. These data are seen by Julia as string and they are formatted like that: "2019-01-23T04:30:00+01:00" I have read the docu…

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## [Julia Seasons of Contributions to supplement GSoC](https://discourse.julialang.org/t/julia-seasons-of-contributions-to-supplement-gsoc/23922)

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**Author:** [@avik](https://discourse.julialang.org/u/avik)\
**Replies:** 9\
**Last updated:** [June 11, 2019, 3:50pm UTC](https://discourse.julialang.org/t/julia-seasons-of-contributions-to-supplement-gsoc/23922 "2019-06-11T15:50:19Z")

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As many of you know, Julia has been a participant in the Google Summer of Code for many years. It has been a very successful initiative for the Julia community. Many important parts of our ecosystem have been created and…

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## [Loading Error in DataArrays package in Julia Console](https://discourse.julialang.org/t/loading-error-in-dataarrays-package-in-julia-console/25152)

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**Author:** [@shahriariit](https://discourse.julialang.org/u/shahriariit)\
**Replies:** 1\
**Last updated:** [June 11, 2019, 2:58pm UTC](https://discourse.julialang.org/t/loading-error-in-dataarrays-package-in-julia-console/25152 "2019-06-11T14:58:24Z")

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I try to load this package and get errors. julia\> using DataArrays \[ Info: Precompiling DataArrays \[0fe7c1db-08c2-54a3-a222-6d1d3b7a471a\] ERROR: LoadError: LoadError: UndefVarError: start not defined Stacktrace: \[1\] ge…

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## [Get Error to load packages in Julia Console](https://discourse.julialang.org/t/get-error-to-load-packages-in-julia-console/25150)

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**Author:** [@shahriariit](https://discourse.julialang.org/u/shahriariit)\
**Replies:** 2\
**Last updated:** [June 11, 2019, 2:37pm UTC](https://discourse.julialang.org/t/get-error-to-load-packages-in-julia-console/25150 "2019-06-11T14:37:42Z")

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I try to load Distributions package but find this errors. julia\> using Distributions \[ Info: Precompiling Distributions \[31c24e10-a181-5473-b8eb-7969acd0382f\] ERROR: LoadError: InitError: C:\\Users\\Satu\\.julia\\package…

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## [Issue with nested pmap](https://discourse.julialang.org/t/issue-with-nested-pmap/25129)

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**Author:** [@abx](https://discourse.julialang.org/u/abx)\
**Replies:** 2\
**Last updated:** [June 11, 2019, 1:55pm UTC](https://discourse.julialang.org/t/issue-with-nested-pmap/25129 "2019-06-11T13:55:03Z")

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Hello, I have this script running in Julia 1.1. If I run it withing a single process (no workers added) everything works fine. If I add process (e.g. addprocs(3)) nothing gets run and the execution hangs indefinitely u…

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## ["literals" in Julia: "immutable values known at compile times"?](https://discourse.julialang.org/t/literals-in-julia-immutable-values-known-at-compile-times/25145)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 2\
**Last updated:** [June 11, 2019, 1:09pm UTC](https://discourse.julialang.org/t/literals-in-julia-immutable-values-known-at-compile-times/25145 "2019-06-11T13:09:20Z")

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Would be correct to say that literals in Julia are “immutable values known at compile times” ?

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## [Callback for a specific variable in an array while calculating differential equations](https://discourse.julialang.org/t/callback-for-a-specific-variable-in-an-array-while-calculating-differential-equations/24895)

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**Author:** [@HelgavonLichtenstein](https://discourse.julialang.org/u/HelgavonLichtenstein)\
**Replies:** 8\
**Last updated:** [June 11, 2019, 11:54am UTC](https://discourse.julialang.org/t/callback-for-a-specific-variable-in-an-array-while-calculating-differential-equations/24895 "2019-06-11T11:54:45Z")

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Hello everyone, How would one apply a callback to a variable in an array while calculating differential equations? I have a complex food web: plants are using nutrients, animals are eating plants,and some animals are b…

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## [Parsing expressions into functions](https://discourse.julialang.org/t/parsing-expressions-into-functions/25108)

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**Author:** [@JesseSantoso](https://discourse.julialang.org/u/JesseSantoso)\
**Replies:** 22\
**Last updated:** [June 11, 2019, 9:17am UTC](https://discourse.julialang.org/t/parsing-expressions-into-functions/25108 "2019-06-11T09:17:17Z")

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Hi, I’m relatively new to Julia but feel like I’m mostly getting the hang of it. I have a project where I need to parse a large number of arbitrary expressions (e.g. ax^b, a+bx^2, etc.) into a function, but I’m running …

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## [SVD solve with CUSOLVER](https://discourse.julialang.org/t/svd-solve-with-cusolver/25130)

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**Author:** [@Donut\_Meepo](https://discourse.julialang.org/u/Donut_Meepo)\
**Replies:** 2\
**Last updated:** [June 11, 2019, 3:37am UTC](https://discourse.julialang.org/t/svd-solve-with-cusolver/25130 "2019-06-11T03:37:55Z")

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Hi, I am trying to do eigen decomposition using CUSOLVER. But it is slower than using CPU. My gpu is GeForce 1060 maybe simply just it is not good enough? I think I am not doing it right hope someone can help me. Thank …

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## [Solving N-dimensional Coupled ODE Systems in DifferentialEquations Jl](https://discourse.julialang.org/t/solving-n-dimensional-coupled-ode-systems-in-differentialequations-jl/24629)

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**Author:** [@Ben\_Hardisty](https://discourse.julialang.org/u/Ben_Hardisty)\
**Replies:** 2\
**Last updated:** [June 11, 2019, 1:01am UTC](https://discourse.julialang.org/t/solving-n-dimensional-coupled-ode-systems-in-differentialequations-jl/24629 "2019-06-11T01:01:22Z")

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So I’ve figured out how to make a simulation of the life-stages of some hypothetical model organism in R. I can use “N” as the number of life-stages, the number of differential equations to be solved, during each simulat…

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## [JuliaDB: convert a Int (0,1) column to Boolean](https://discourse.julialang.org/t/juliadb-convert-a-int-0-1-column-to-boolean/25124)

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**Author:** [@GdMacmillan](https://discourse.julialang.org/u/GdMacmillan)\
**Replies:** 2\
**Last updated:** [June 10, 2019, 11:33pm UTC](https://discourse.julialang.org/t/juliadb-convert-a-int-0-1-column-to-boolean/25124 "2019-06-10T23:33:38Z")

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Hi, pretty straightforward question here: How would I go about converting a JuliaDB table column of type Int64 to Boolean values so I can run counts… I was thinking something like select(t, :is\_bad =\> convert) but conv…

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## [Float64 reduction of Float32 computation idiom using @distributed?](https://discourse.julialang.org/t/float64-reduction-of-float32-computation-idiom-using-distributed/25085)

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**Author:** [@fghorow](https://discourse.julialang.org/u/fghorow)\
**Replies:** 8\
**Last updated:** [June 10, 2019, 10:45pm UTC](https://discourse.julialang.org/t/float64-reduction-of-float32-computation-idiom-using-distributed/25085 "2019-06-10T22:45:51Z")

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I have a computation where hundreds of millions of Float32 values (for speed) need to be reduction summed in Float64 accumulators. Assuming the reduction is being driven by something like: accum = Array{Float64}(undef,…

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## [Bug? JuliaPro Distributed Procs](https://discourse.julialang.org/t/bug-juliapro-distributed-procs/24964)

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**Author:** [@dburch](https://discourse.julialang.org/u/dburch)\
**Replies:** 1\
**Last updated:** [June 10, 2019, 8:36pm UTC](https://discourse.julialang.org/t/bug-juliapro-distributed-procs/24964 "2019-06-10T20:36:07Z")

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\[Side Note: Where should I report bugs for JuliaPro?\] In reference to this post. The following code works in the Julia console version (tried 1.0.4 and 1.1.1), but it is broken in JuliaPro (tried 1.0.3 and 1.0.4): usi…

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## [Help with .travis.yml](https://discourse.julialang.org/t/help-with-travis-yml/25017)

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**Author:** [@goedman](https://discourse.julialang.org/u/goedman)\
**Replies:** 4\
**Last updated:** [June 10, 2019, 8:35pm UTC](https://discourse.julialang.org/t/help-with-travis-yml/25017 "2019-06-10T20:35:17Z")

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For several years I’ve been testing Cmdstan.jl (previously Stan.jl) with a script like below. I updated building the docs mid last year and attempted to use stages, with limited success, but at least early on below scrip…

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## [V1.0 Pkg - Can't copy packages](https://discourse.julialang.org/t/v1-0-pkg-cant-copy-packages/18764)

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**Author:** [@Glen1](https://discourse.julialang.org/u/Glen1)\
**Replies:** 8\
**Last updated:** [June 10, 2019, 8:23pm UTC](https://discourse.julialang.org/t/v1-0-pkg-cant-copy-packages/18764 "2019-06-10T20:23:15Z")

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I’m so frustrated. We’ve implemented our whole production environment in Julia and working really well, but can’t get v1.0 packages working. We are behind a firewall, so can’t add/download packages, so I currently have…

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## [Clipping gradients with Zygote/Flux](https://discourse.julialang.org/t/clipping-gradients-with-zygote-flux/25052)

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**Author:** [@mlpeschl](https://discourse.julialang.org/u/mlpeschl)\
**Replies:** 2\
**Last updated:** [June 10, 2019, 8:16pm UTC](https://discourse.julialang.org/t/clipping-gradients-with-zygote-flux/25052 "2019-06-10T20:16:32Z")

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I am currently working with Flux and due to a high amount of stochasticity in my data, I often receive “Loss is NaN” and “Loss is infinite” errors during training. Reducing the stepsize of my gradient updates of course …

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## [ISC-HPC conference 2019](https://discourse.julialang.org/t/isc-hpc-conference-2019/25127)

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**Author:** [@ffevotte](https://discourse.julialang.org/u/ffevotte)\
**Replies:** 0\
**Last updated:** [June 10, 2019, 7:39pm UTC](https://discourse.julialang.org/t/isc-hpc-conference-2019/25127 "2019-06-10T19:39:10Z")

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Hello, I’ll be at the ISC HPC conference, which takes place in Frankfurt from June 16th to June 20th. Will there be other Julians there? There does not seem to be any Julia-related event planned, but that does not preve…

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## [Sundials.jl --\> LoadError: TypeError: in cfunction, expected Union{}, got Int32](https://discourse.julialang.org/t/sundials-jl-loaderror-typeerror-in-cfunction-expected-union-got-int32/25059)

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**Author:** [@Boris\_Penaloza](https://discourse.julialang.org/u/Boris_Penaloza)\
**Replies:** 2\
**Last updated:** [June 10, 2019, 5:54pm UTC](https://discourse.julialang.org/t/sundials-jl-loaderror-typeerror-in-cfunction-expected-union-got-int32/25059 "2019-06-10T17:54:41Z")

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Hello guys, I am trying to solve a ODE using the CVODE\_BDF() solver of the Sundials package. Here is a snippet of my code: Defining the function function f(dX, X, p, t) #A, B, D, E, Inh = p #dX = -A\*X + (B - X)\*E - (…

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## [PSA: Creating tags](https://discourse.julialang.org/t/psa-creating-tags/25122)

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**Author:** [@vchuravy](https://discourse.julialang.org/u/vchuravy)\
**Replies:** 0\
**Last updated:** [June 10, 2019, 5:36pm UTC](https://discourse.julialang.org/t/psa-creating-tags/25122 "2019-06-10T17:36:12Z")

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In Why are there so little categories and optional tags? - #6 by vchuravy it is noted that we have only a few tags! The list of tags can be seen here JuliaLang and I just wanted to remind everyone that if they have TL3 …

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## [State of Plotting Packages as of 2018/12/15](https://discourse.julialang.org/t/state-of-plotting-packages-as-of-2018-12-15/18698)

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**Author:** [@jleman](https://discourse.julialang.org/u/jleman)\
**Replies:** 39\
**Last updated:** [June 10, 2019, 5:22pm UTC](https://discourse.julialang.org/t/state-of-plotting-packages-as-of-2018-12-15/18698 "2019-06-10T17:22:36Z")

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Question: Which plotting package seems to have brightest future when it comes to engineering application? Using Atom/Juno, Julia 1.0.2, Windows 10. Background and comments: I am working on a PhD in electrical engineeri…

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## [Rotating cube in Makie not working](https://discourse.julialang.org/t/rotating-cube-in-makie-not-working/25116)

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**Author:** [@Noel\_Araujo](https://discourse.julialang.org/u/Noel_Araujo)\
**Replies:** 1\
**Last updated:** [June 10, 2019, 1:54pm UTC](https://discourse.julialang.org/t/rotating-cube-in-makie-not-working/25116 "2019-06-10T13:54:21Z")

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Hello, I just found this example of a cube that should be rotating link: using Makie N = 40 interval = 0.10 scene = mesh(FRect3D(Vec3f0(-0.5), Vec3f0(1)), color = :skyblue2) rect = scene\[end\] for rad in 0.5:1/N:…

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## [Invalid escape sequence](https://discourse.julialang.org/t/invalid-escape-sequence/19805)

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**Author:** [@S.stark](https://discourse.julialang.org/u/S.stark)\
**Replies:** 1\
**Last updated:** [June 10, 2019, 12:52pm UTC](https://discourse.julialang.org/t/invalid-escape-sequence/19805 "2019-06-10T12:52:59Z")

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I’m studying Genie from the example in GitHub - GenieFramework/Genie.jl: 🧞The highly productive Julia web framework When I was trying connect SearchLight to DB, using the following command: julia\> SearchLight.Configura…

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## [LSTM on a GPU](https://discourse.julialang.org/t/lstm-on-a-gpu/25113)

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**Author:** [@tanhevg](https://discourse.julialang.org/u/tanhevg)\
**Replies:** 0\
**Last updated:** [June 10, 2019, 11:06am UTC](https://discourse.julialang.org/t/lstm-on-a-gpu/25113 "2019-06-10T11:06:17Z")

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Hello, I am trying to run the Flux model zoo LSTM example on a GPU. Turns out there is no performance improvement; on the contrary, it gets worse. The example uses ~500mb of training data, and each epoch runs for ~25se…

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## [Precompiling Makie on Windows](https://discourse.julialang.org/t/precompiling-makie-on-windows/25112)

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**Author:** [@dawbarton](https://discourse.julialang.org/u/dawbarton)\
**Replies:** 3\
**Last updated:** [June 10, 2019, 10:44am UTC](https://discourse.julialang.org/t/precompiling-makie-on-windows/25112 "2019-06-10T10:44:52Z")

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Is it possible to precompile Makie on Windows? I’ve just tried on my Linux machine and it works perfectly but on Windows I get an error about “Task cannot be serialized”; see below for the output \<\<\<snip\>\>\> Test Summary…

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## [How to know what types will the type signature match?](https://discourse.julialang.org/t/how-to-know-what-types-will-the-type-signature-match/25105)

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**Author:** [@singularitti](https://discourse.julialang.org/u/singularitti)\
**Replies:** 6\
**Last updated:** [June 10, 2019, 7:04am UTC](https://discourse.julialang.org/t/how-to-know-what-types-will-the-type-signature-match/25105 "2019-06-10T07:04:05Z")

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When writing some function signatures, I sometimes want to know what types will match them. For example, f(::AbstractVector{Real}) = 1 f(::AbstractVector{\<: Real}) = 2 They are quite similar and sometimes could confus…

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## [Filling arrays in rows](https://discourse.julialang.org/t/filling-arrays-in-rows/25097)

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**Author:** [@STHossain](https://discourse.julialang.org/u/STHossain)\
**Replies:** 4\
**Last updated:** [June 9, 2019, 6:25pm UTC](https://discourse.julialang.org/t/filling-arrays-in-rows/25097 "2019-06-09T18:25:33Z")

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Hi, Could someone please help me to figure out how a matrix could be filled in rows. So if I give some numbers with dimension then they would form a 2 dimensional array but it will start filling from the first row, the…

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## [How to read big data chunk by chunk(column-wise chunking)?](https://discourse.julialang.org/t/how-to-read-big-data-chunk-by-chunk-column-wise-chunking/25084)

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**Author:** [@Carol](https://discourse.julialang.org/u/Carol)\
**Replies:** 5\
**Last updated:** [June 9, 2019, 4:53pm UTC](https://discourse.julialang.org/t/how-to-read-big-data-chunk-by-chunk-column-wise-chunking/25084 "2019-06-09T16:53:43Z")

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Hi, could you please tell me how to read data chunk by chunk? For example, read 100 columns at one time, like: sub\_data=read\_data(file, start\_column=1,end\_column=100) After n-iteration, I can process all of my 100n co…

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## [Rank of admission and subtraction](https://discourse.julialang.org/t/rank-of-admission-and-subtraction/25065)

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**Author:** [@GERSON\_EZEQUIEL\_HERN](https://discourse.julialang.org/u/GERSON_EZEQUIEL_HERN)\
**Replies:** 3\
**Last updated:** [June 9, 2019, 11:17am UTC](https://discourse.julialang.org/t/rank-of-admission-and-subtraction/25065 "2019-06-09T11:17:59Z")

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How could you define the range in admission and subtraction over an image? enter (0-255) without going past 255 or reducing me from 0. my code is something like this … #= admiminsion and subtracion =# R₁ = float.(imgg…

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## [What's the easiest stdlib if one wants to learn (and contribute) Julia?](https://discourse.julialang.org/t/whats-the-easiest-stdlib-if-one-wants-to-learn-and-contribute-julia/25062)

<div class="topic-metadata">

**Author:** [@affans](https://discourse.julialang.org/u/affans)\
**Replies:** 3\
**Last updated:** [June 9, 2019, 11:03am UTC](https://discourse.julialang.org/t/whats-the-easiest-stdlib-if-one-wants-to-learn-and-contribute-julia/25062 "2019-06-09T11:03:36Z")

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I’ve been programming in Julia since the 0.5 days. However, I find that my understanding of certain language features, multiple dispatch, macros, and package manager is weak. The documentation helps, but I find that writ…

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