# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1855

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

**Page:** 1856

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## [Julia 1.0.2 cannot find libraries under vglrun](https://discourse.julialang.org/t/julia-1-0-2-cannot-find-libraries-under-vglrun/17977)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 1\
**Last updated:** [December 26, 2019, 5:25pm UTC](https://discourse.julialang.org/t/julia-1-0-2-cannot-find-libraries-under-vglrun/17977 "2019-12-26T17:25:34Z")

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When I try to start julia in a virtual GL environment (needed for Makie) julia 1.0 fails, even though julia 0.7 and 0.6 work. It fails with the following failure: ufechner@TUD277255:~$ vglrun julia1 WARNING: Error durin…

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## [DataFrame no longer is displayed in console](https://discourse.julialang.org/t/dataframe-no-longer-is-displayed-in-console/32717)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 4\
**Last updated:** [December 26, 2019, 4:42pm UTC](https://discourse.julialang.org/t/dataframe-no-longer-is-displayed-in-console/32717 "2019-12-26T16:42:36Z")

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In the terminal of vscode I cannot see any longer the content of any dataframe. I doesn’t make a difference if I start julia in the terminal or the “Julia REPL” plugin. Example: julia\> using DataFrames; …

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## [Putting results of diffrent arrays for one variable in one array](https://discourse.julialang.org/t/putting-results-of-diffrent-arrays-for-one-variable-in-one-array/32708)

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**Author:** [@marouane](https://discourse.julialang.org/u/marouane)\
**Replies:** 13\
**Last updated:** [December 26, 2019, 1:32pm UTC](https://discourse.julialang.org/t/putting-results-of-diffrent-arrays-for-one-variable-in-one-array/32708 "2019-12-26T13:32:15Z")

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Basically i have this small piece of code when i get: function scan\_maker(A) m = JuMP.Model(solver=ClpSolver(PrimalTolerance=1e-3, DualTolerance=1e-3, InfeasibleReturn=1, PresolveType=1)) # m = Model(solver=Guro…

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## [VegaLite.jl; what needs doing?](https://discourse.julialang.org/t/vegalite-jl-what-needs-doing/31940)

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**Author:** [@Usor](https://discourse.julialang.org/u/Usor)\
**Replies:** 12\
**Last updated:** [December 26, 2019, 1:24pm UTC](https://discourse.julialang.org/t/vegalite-jl-what-needs-doing/31940 "2019-12-26T13:24:50Z")

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I do not consider myself great at VegaLite.jl and I don’t know all its elements. I am still getting used to it more and more and don’t always have much time. Still I am interested in possibly helping with this project. I…

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## [Exercise in DiffEqTutorials, "Failed to build the parameter derivatives"](https://discourse.julialang.org/t/exercise-in-diffeqtutorials-failed-to-build-the-parameter-derivatives/32711)

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**Author:** [@yuxi.liu](https://discourse.julialang.org/u/yuxi.liu)\
**Replies:** 1\
**Last updated:** [December 26, 2019, 12:42pm UTC](https://discourse.julialang.org/t/exercise-in-diffeqtutorials-failed-to-build-the-parameter-derivatives/32711 "2019-12-26T12:42:53Z")

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This is from the tutorial of DiffEqTutorials, Callbacks and Events, exercise 2: using DifferentialEquations, ParameterizedFunctions ball! = @ode\_def BallBounce begin dy = v dv = -g + k\*v end g e k throws error ┌ …

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## [Plotting differential equation solutions](https://discourse.julialang.org/t/plotting-differential-equation-solutions/32705)

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**Author:** [@yuxi.liu](https://discourse.julialang.org/u/yuxi.liu)\
**Replies:** 1\
**Last updated:** [December 26, 2019, 12:29pm UTC](https://discourse.julialang.org/t/plotting-differential-equation-solutions/32705 "2019-12-26T12:29:21Z")

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The following code runs really slowly, because it redraws the graph every update, instead of incrementally. There must be some method for incremental diagramming, but I can’t find any. There should be a way to plot this…

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## [Error Symbolic calculations could not initiate. Likely there's a function which is not differentiable by SymEngine](https://discourse.julialang.org/t/error-symbolic-calculations-could-not-initiate-likely-theres-a-function-which-is-not-differentiable-by-symengine/32707)

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**Author:** [@yuxi.liu](https://discourse.julialang.org/u/yuxi.liu)\
**Replies:** 1\
**Last updated:** [December 26, 2019, 12:28pm UTC](https://discourse.julialang.org/t/error-symbolic-calculations-could-not-initiate-likely-theres-a-function-which-is-not-differentiable-by-symengine/32707 "2019-12-26T12:28:37Z")

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I’m simulating a satellite around the earth, and got error: Symbolic calculations could not initiate. Likely there's a function which is not differentiable by SymEngine. I think it’s because it cannot differentiate the…

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## [TimeSeries.jl: How to set the meta field in TimeArray (of TimeSeries.jl) after the array is constructed?](https://discourse.julialang.org/t/timeseries-jl-how-to-set-the-meta-field-in-timearray-of-timeseries-jl-after-the-array-is-constructed/32703)

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**Author:** [@zdenek\_hurak](https://discourse.julialang.org/u/zdenek_hurak)\
**Replies:** 1\
**Last updated:** [December 26, 2019, 11:09am UTC](https://discourse.julialang.org/t/timeseries-jl-how-to-set-the-meta-field-in-timearray-of-timeseries-jl-after-the-array-is-constructed/32703 "2019-12-26T11:09:13Z")

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Is it possible to set the meta field in a TimeArray (of the TimeSeries.jl package) after the array is defined? The only discussion of meta field in the manual is in the section on constructors. But what if my time array…

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## [Automerge.run error when registering for package](https://discourse.julialang.org/t/automerge-run-error-when-registering-for-package/32690)

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**Author:** [@rakshit\_naidu](https://discourse.julialang.org/u/rakshit_naidu)\
**Replies:** 2\
**Last updated:** [December 26, 2019, 11:09am UTC](https://discourse.julialang.org/t/automerge-run-error-when-registering-for-package/32690 "2019-12-26T11:09:39Z")

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I have followed the instructions to register my package using Registrator.jl I face an error in the last step of the Automerge.run I have also added CompatHelper.jl to my repo. Need some help to figure out what’s goin…

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## [Plotting vector fields](https://discourse.julialang.org/t/plotting-vector-fields/32704)

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**Author:** [@yuxi.liu](https://discourse.julialang.org/u/yuxi.liu)\
**Replies:** 5\
**Last updated:** [December 26, 2019, 8:27am UTC](https://discourse.julialang.org/t/plotting-vector-fields/32704 "2019-12-26T08:27:03Z")

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I wrote this down because it is weirdly hard to find anything on this topic. To plot vector fields, use the undocumented (as of 2019 Dec 26) quiver function. Quiver is a strange name, coming from the military: a “quiver…

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## [Failed to load \`CUDAdrv\`](https://discourse.julialang.org/t/failed-to-load-cudadrv/32524)

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**Author:** [@affans](https://discourse.julialang.org/u/affans)\
**Replies:** 3\
**Last updated:** [December 26, 2019, 1:02am UTC](https://discourse.julialang.org/t/failed-to-load-cudadrv/32524 "2019-12-26T01:02:22Z")

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I am, for the first time, trying to learn how GPU programming works. I have two Tesla K80s on a HPC. To begin I request the proper node through slurm, and launch an interactive job. \[affans@hpc ~\]$ srun -p gpuq --gres=g…

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## [Tips to create beautiful, publication-quality plots](https://discourse.julialang.org/t/tips-to-create-beautiful-publication-quality-plots/32384)

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**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 28\
**Last updated:** [December 26, 2019, 12:54am UTC](https://discourse.julialang.org/t/tips-to-create-beautiful-publication-quality-plots/32384 "2019-12-26T00:54:37Z")

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Edit: an equivalent blog post is available here, as suggested by colleagues: https://nextjournal.com/leandromartinez98/tips-to-create-beautiful-publication-quality-plots-in-julia I was about to send an e-mail to my st…

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## [VegaLite.jl; sorting problematic](https://discourse.julialang.org/t/vegalite-jl-sorting-problematic/31939)

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**Author:** [@Usor](https://discourse.julialang.org/u/Usor)\
**Replies:** 4\
**Last updated:** [December 25, 2019, 8:47pm UTC](https://discourse.julialang.org/t/vegalite-jl-sorting-problematic/31939 "2019-12-25T20:47:51Z")

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I looked on the site to translate some things to see hoe and if it worked: Sorting | Vega-Lite If I want to use for some channel (y) the x channel, then taking their example doesn’t work and gives no result, unless I us…

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## [Can't test package: "in manifest but not in project"](https://discourse.julialang.org/t/cant-test-package-in-manifest-but-not-in-project/32663)

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**Author:** [@yha](https://discourse.julialang.org/u/yha)\
**Replies:** 3\
**Last updated:** [December 25, 2019, 7:46pm UTC](https://discourse.julialang.org/t/cant-test-package-in-manifest-but-not-in-project/32663 "2019-12-25T19:46:37Z")

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I have the registered CircularArrays package deved, but I can’t test it, and can’t make sense of the error message (v1.3) pkg\> status CircularArrays Status \`C:\\Users\\sternlab\\.julia\\environments\\v1.3\\Project.toml\` …

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## [Usage of keyword \`const\` in the context of types. (code from Julia documentation)](https://discourse.julialang.org/t/usage-of-keyword-const-in-the-context-of-types-code-from-julia-documentation/32654)

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**Author:** [@reumle](https://discourse.julialang.org/u/reumle)\
**Replies:** 4\
**Last updated:** [December 25, 2019, 7:42pm UTC](https://discourse.julialang.org/t/usage-of-keyword-const-in-the-context-of-types-code-from-julia-documentation/32654 "2019-12-25T19:42:26Z")

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Hi, I read this in Julia doc (Types · The Julia Language) julia\> const T1 = Array{Array{T,1} where T, 1} Array{Array{T,1} where T,1} What is the meaning of const in this context? eg I built a variable like here below…

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## [How to check if all fields of a Tuple are the same](https://discourse.julialang.org/t/how-to-check-if-all-fields-of-a-tuple-are-the-same/32700)

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**Author:** [@pdeffebach](https://discourse.julialang.org/u/pdeffebach)\
**Replies:** 2\
**Last updated:** [December 25, 2019, 7:41pm UTC](https://discourse.julialang.org/t/how-to-check-if-all-fields-of-a-tuple-are-the-same/32700 "2019-12-25T19:41:35Z")

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Let’s say you have julia\> t = (\[1, 2\], \["a", "b"\]) (\[1, 2\], \["a", "b"\]) julia\> typeof(t) Tuple{Array{Int64,1},Array{String,1}} Let’s say I have a function that takes in a tuple of abstract arrays, and I really need th…

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## [Breaking a list into chunks of size N](https://discourse.julialang.org/t/breaking-a-list-into-chunks-of-size-n/32697)

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**Author:** [@PseudoCodeNerd](https://discourse.julialang.org/u/PseudoCodeNerd)\
**Replies:** 2\
**Last updated:** [December 25, 2019, 6:05pm UTC](https://discourse.julialang.org/t/breaking-a-list-into-chunks-of-size-n/32697 "2019-12-25T18:05:38Z")

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Hello there ! I’m trying to break a list into chunks of size N . Here’s the code which I’ve written julia\> function chunk(arr,n) \[arr\[i \* n:(i + 1) \* n\] for i in \[(length(arr)+n-1)//n\]\] end Can someone…

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## [Parallel loop in numeric order](https://discourse.julialang.org/t/parallel-loop-in-numeric-order/32592)

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**Author:** [@Diger](https://discourse.julialang.org/u/Diger)\
**Replies:** 7\
**Last updated:** [December 25, 2019, 3:53pm UTC](https://discourse.julialang.org/t/parallel-loop-in-numeric-order/32592 "2019-12-25T15:53:13Z")

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Running a loop is in numeric order for i=1:100 println(i) end Is it possible to run a parallel loop in order? @sync @distributed for i=1:100 println(i) end I figure it is not fully possible to fully run it in ord…

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## [Inferring the type of an operation for \`struct\` fields](https://discourse.julialang.org/t/inferring-the-type-of-an-operation-for-struct-fields/32694)

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**Author:** [@OvidiusCicero](https://discourse.julialang.org/u/OvidiusCicero)\
**Replies:** 4\
**Last updated:** [December 25, 2019, 3:26pm UTC](https://discourse.julialang.org/t/inferring-the-type-of-an-operation-for-struct-fields/32694 "2019-12-25T15:26:01Z")

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I have a struct struct Test divisor::Int64 dividend::Int64 result::Float64 end Test(divisor, dividend) = Test(divisor, dividend, divisor/dividend) I want to make a template out of this struct such that inst…

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## [Julia 1.3 order of magnitude slowdown in function](https://discourse.julialang.org/t/julia-1-3-order-of-magnitude-slowdown-in-function/32691)

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**Author:** [@joshua\_jones](https://discourse.julialang.org/u/joshua_jones)\
**Replies:** 1\
**Last updated:** [December 25, 2019, 1:19pm UTC](https://discourse.julialang.org/t/julia-1-3-order-of-magnitude-slowdown-in-function/32691 "2019-12-25T13:19:59Z")

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Cross-posted from https://github.com/JuliaLang/julia/issues/34195 I’m noticing an order-of-magnitude slowdown in a custom function to parse “sample list” files (one ASCII value per line) to Float32 arrays. Any ideas wha…

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## [PosDefManifoldML: machine learning for positive definite matrices](https://discourse.julialang.org/t/posdefmanifoldml-machine-learning-for-positive-definite-matrices/32620)

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**Author:** [@Marco-Congedo](https://discourse.julialang.org/u/Marco-Congedo)\
**Replies:** 17\
**Last updated:** [December 25, 2019, 11:35am UTC](https://discourse.julialang.org/t/posdefmanifoldml-machine-learning-for-positive-definite-matrices/32620 "2019-12-25T11:35:14Z")

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Hello all, PosDefManifoldML is a Python-free package for classifying data in the Riemannian manifolds P of real or complex positive definite matrices, for example, covariance matrices, Fourier cross-spectral matrices, k…

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## [Package cannot be installed on Julia 1.0.4](https://discourse.julialang.org/t/package-cannot-be-installed-on-julia-1-0-4/32687)

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**Author:** [@rakshit\_naidu](https://discourse.julialang.org/u/rakshit_naidu)\
**Replies:** 4\
**Last updated:** [December 25, 2019, 11:29am UTC](https://discourse.julialang.org/t/package-cannot-be-installed-on-julia-1-0-4/32687 "2019-12-25T11:29:55Z")

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I cannot install my Package in Julia. Github link for my package: https://github.com/r0cketr1kky/Dogsay.jl I tried to install it by using Pkg; Pkg.add(“Dogsay”) and I keep getting the following error: ERROR: The foll…

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## [Errors in Travis-CI for building a new package](https://discourse.julialang.org/t/errors-in-travis-ci-for-building-a-new-package/32686)

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**Author:** [@rakshit\_naidu](https://discourse.julialang.org/u/rakshit_naidu)\
**Replies:** 2\
**Last updated:** [December 25, 2019, 10:28am UTC](https://discourse.julialang.org/t/errors-in-travis-ci-for-building-a-new-package/32686 "2019-12-25T10:28:28Z")

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My github repo link is: https://github.com/r0cketr1kky/Dogsay.jl I have more than 40 builds and I still can’t figure out my error. It would be great if someone could assist me in packaging my code for Julia. The Error…

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## [BoundsError: attempt to access 0-element Array{JuMP.Variable,1} at index \[1\]](https://discourse.julialang.org/t/boundserror-attempt-to-access-0-element-array-jump-variable-1-at-index-1/32683)

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**Author:** [@marouane1994](https://discourse.julialang.org/u/marouane1994)\
**Replies:** 0\
**Last updated:** [December 25, 2019, 7:30am UTC](https://discourse.julialang.org/t/boundserror-attempt-to-access-0-element-array-jump-variable-1-at-index-1/32683 "2019-12-25T07:30:24Z")

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i have this function: function prob(na) b = T0\*na setc(-b) total = 0.0 for x in Channel(scan) nab = vi2\*x + b #the photon numbers for each item in the sum in the note (10) …

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## [Is there a tool to organize imports/using statements?](https://discourse.julialang.org/t/is-there-a-tool-to-organize-imports-using-statements/32670)

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**Author:** [@Qiyamah](https://discourse.julialang.org/u/Qiyamah)\
**Replies:** 1\
**Last updated:** [December 25, 2019, 7:56am UTC](https://discourse.julialang.org/t/is-there-a-tool-to-organize-imports-using-statements/32670 "2019-12-25T07:56:44Z")

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Hi, I have bunch of modules which uses using …SomeOtherModule however I want to transform them into using …SomeOtherModule: f1,f2 which shows exactly which functions and fields are being used from that particular mo…

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## [Where does where go?](https://discourse.julialang.org/t/where-does-where-go/32570)

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**Author:** [@tk3369](https://discourse.julialang.org/u/tk3369)\
**Replies:** 5\
**Last updated:** [December 25, 2019, 6:26am UTC](https://discourse.julialang.org/t/where-does-where-go/32570 "2019-12-25T06:26:27Z")

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I generally write function signatures with the where-clause outside of the arguments list. Is there any reason why one would put that inside the function signature? e.g. foo(x::T where T) = 1 foo(x::T) where T = 2 fo…

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## [Why is Base.summarysize not loaded like Base.summary?](https://discourse.julialang.org/t/why-is-base-summarysize-not-loaded-like-base-summary/32674)

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**Author:** [@yuxi.liu](https://discourse.julialang.org/u/yuxi.liu)\
**Replies:** 1\
**Last updated:** [December 25, 2019, 4:43am UTC](https://discourse.julialang.org/t/why-is-base-summarysize-not-loaded-like-base-summary/32674 "2019-12-25T04:43:32Z")

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When I start up julia REPL, Base.summary is loaded and I can use it directly like summary, but Base.summarysize must be used like Base.summarysize, else: julia\> summarysize ERROR: UndefVarError: summarysize not defined

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## [SplitApplyCombine.jl \`group\` enhancements, reaches version 1.0.0](https://discourse.julialang.org/t/splitapplycombine-jl-group-enhancements-reaches-version-1-0-0/32675)

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**Author:** [@andyferris](https://discourse.julialang.org/u/andyferris)\
**Replies:** 1\
**Last updated:** [December 25, 2019, 3:13am UTC](https://discourse.julialang.org/t/splitapplycombine-jl-group-enhancements-reaches-version-1-0-0/32675 "2019-12-25T03:13:07Z")

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Merry Chirstmas everybody, Today I have released version 1.0.0 of SplitApplyCombine.jl, with the headline feature being that grouping functions have moved to returning a dictionary from Dictionaries.jl. On a personal n…

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## [Undefined variable of function side while loop](https://discourse.julialang.org/t/undefined-variable-of-function-side-while-loop/32668)

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**Author:** [@locluong09](https://discourse.julialang.org/u/locluong09)\
**Replies:** 3\
**Last updated:** [December 24, 2019, 10:15pm UTC](https://discourse.julialang.org/t/undefined-variable-of-function-side-while-loop/32668 "2019-12-24T22:15:42Z")

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I have a function inside a while loop like the code below, but get problem ERROR: UndefVarError: Pre\_predict not defined. Pre\_predict = zeros(Row, Col) while true N,S,W,E,C,Q = construct\_Tran\_matrix(Pre\_init, \*\*Pre\_…

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## [Issue with BNN example from Turing Tutorial](https://discourse.julialang.org/t/issue-with-bnn-example-from-turing-tutorial/32665)

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**Author:** [@nucklass](https://discourse.julialang.org/u/nucklass)\
**Replies:** 3\
**Last updated:** [December 24, 2019, 7:53pm UTC](https://discourse.julialang.org/t/issue-with-bnn-example-from-turing-tutorial/32665 "2019-12-24T19:53:32Z")

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Hi, student and first time poster here. I’ve been trying to work through the tutorials from the Turing documentation, and can’t seem to get the Bayesian Neural Network to run. More specifically, it seems to stem from th…

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