# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=510

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**Page:** 511

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## [ANN: Knet v1.2.0: iterators, iterators, iterators](https://discourse.julialang.org/t/ann-knet-v1-2-0-iterators-iterators-iterators/19905)

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**Author:** [@denizyuret](https://discourse.julialang.org/u/denizyuret)\
**Replies:** 8\
**Last updated:** [January 27, 2019, 10:24pm UTC](https://discourse.julialang.org/t/ann-knet-v1-2-0-iterators-iterators-iterators/19905 "2019-01-27T22:24:59Z")

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The new Knet release is all about iterators: iterators for minibatching, iterators for training, iterators for monitoring, convergence etc. Why am I so excited about iterators all of a sudden? Allow me to explain: Knet …

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## [DifferentialEquations.jl: marked point processes (or storing user data)](https://discourse.julialang.org/t/differentialequations-jl-marked-point-processes-or-storing-user-data/19453)

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**Author:** [@yha](https://discourse.julialang.org/u/yha)\
**Replies:** 6\
**Last updated:** [January 27, 2019, 4:27pm UTC](https://discourse.julialang.org/t/differentialequations-jl-marked-point-processes-or-storing-user-data/19453 "2019-01-27T16:27:19Z")

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I’m trying to simulate a simple marked point process with DifferentialEquations. As far as I can tell, this is not directly supported (the documentation does mention a mark in the context of RegularJump, but this seems t…

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## [\`sync\_threads()\` doesn't seem to work within a loop](https://discourse.julialang.org/t/sync-threads-doesnt-seem-to-work-within-a-loop/20144)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 8\
**Last updated:** [January 27, 2019, 11:38am UTC](https://discourse.julialang.org/t/sync-threads-doesnt-seem-to-work-within-a-loop/20144 "2019-01-27T11:38:35Z")

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I am trying to run sync\_threads() within a GPU kernel but I can’t seem to get it to work within a for loop. Here is the MWE using CuArrays, CUDAnative, CUDAdrv import Flux: cpu CuArrays.allowscalar(false) x = cu(rand(…

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## [Solvers fail on nonlinear problem (which has solutions)](https://discourse.julialang.org/t/solvers-fail-on-nonlinear-problem-which-has-solutions/20051)

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**Author:** [@Torkel](https://discourse.julialang.org/u/Torkel)\
**Replies:** 30\
**Last updated:** [January 26, 2019, 4:51pm UTC](https://discourse.julialang.org/t/solvers-fail-on-nonlinear-problem-which-has-solutions/20051 "2019-01-26T16:51:36Z")

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(quite long text, but I wanted to put down everything I had on the problem) I have been having this set of non-linear equations which I have been trying to solve for a while now. I initially tried NLsolve.jl, however, i…

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## [What does \`groupby\` use to determine equality?](https://discourse.julialang.org/t/what-does-groupby-use-to-determine-equality/20106)

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**Author:** [@ExpandingMan](https://discourse.julialang.org/u/ExpandingMan)\
**Replies:** 3\
**Last updated:** [January 26, 2019, 1:39pm UTC](https://discourse.julialang.org/t/what-does-groupby-use-to-determine-equality/20106 "2019-01-26T13:39:30Z")

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I have a dataframe with some custom types in one of the columns I’d like to groupby. This doesn’t seem to work correctly as the groupby seems to consider objects that are == and have identical hash to be distinct. What…

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## [Controlling the data --\> color gradient mapping in Plots](https://discourse.julialang.org/t/controlling-the-data-color-gradient-mapping-in-plots/20096)

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**Author:** [@tobydriscoll](https://discourse.julialang.org/u/tobydriscoll)\
**Replies:** 3\
**Last updated:** [January 25, 2019, 7:31pm UTC](https://discourse.julialang.org/t/controlling-the-data-color-gradient-mapping-in-plots/20096 "2019-01-25T19:31:01Z")

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x = (0:80)/80; y = @.sin(3\*exp(x)); using Plots cg = cgrad(:viridis,range(0,stop=1,length=64)) plot(x,y,line\_z=y,color=cg) What I get (this is GR, but other backends seem to be similar): This is not what I expecte…

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## [About the convention for the design matrix (row-as-observation or column-as-observation)](https://discourse.julialang.org/t/about-the-convention-for-the-design-matrix-row-as-observation-or-column-as-observation/20080)

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**Author:** [@tlienart](https://discourse.julialang.org/u/tlienart)\
**Replies:** 3\
**Last updated:** [January 25, 2019, 12:26pm UTC](https://discourse.julialang.org/t/about-the-convention-for-the-design-matrix-row-as-observation-or-column-as-observation/20080 "2019-01-25T12:26:43Z")

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At the risk of resucitating an old discussion… I was exploring some of the code in JuliaStats and Clustering and realised that a convention often used in these packages (and in similar ones like GaussianProcesses) is th…

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## [How to fit MixedModels with the option REML=TRUE?](https://discourse.julialang.org/t/how-to-fit-mixedmodels-with-the-option-reml-true/19746)

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**Author:** [@Juan](https://discourse.julialang.org/u/Juan)\
**Replies:** 5\
**Last updated:** [January 25, 2019, 7:20am UTC](https://discourse.julialang.org/t/how-to-fit-mixedmodels-with-the-option-reml-true/19746 "2019-01-25T07:20:37Z")

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I need to use the package MixedModels.jl for regression with random effects. I’ve created the following toy example. using DataFrames, MixedModels, StatsBase, Distributions, LinearAlgebra, SparseArrays N=50 x1 = rep…

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## [Studentized Range Distribution?](https://discourse.julialang.org/t/studentized-range-distribution/20050)

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**Author:** [@BioTurboNick](https://discourse.julialang.org/u/BioTurboNick)\
**Replies:** 3\
**Last updated:** [January 24, 2019, 9:56pm UTC](https://discourse.julialang.org/t/studentized-range-distribution/20050 "2019-01-24T21:56:14Z")

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I may be missing it, but does Distributions.jl contain the q (Studentized range) distribution? This is the one used for post-hoc multiple comparisons. Defined by degrees of freedom (nu) and number of comparisons (k).

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## [JuliaDB: GroupViews](https://discourse.julialang.org/t/juliadb-groupviews/20045)

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**Author:** [@anon92994695](https://discourse.julialang.org/u/anon92994695)\
**Replies:** 0\
**Last updated:** [January 24, 2019, 5:10pm UTC](https://discourse.julialang.org/t/juliadb-groupviews/20045 "2019-01-24T17:10:42Z")

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I’ve found it particularly useful to view JuliaDB tables by chunks (denoted either by their primary keys, or a subset of the indexing key). Is there any plan to implement anything like the following into the library(whet…

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## [DiffEqFlux.jl – A Julia Library for Neural Differential Equations](https://discourse.julialang.org/t/diffeqflux-jl-a-julia-library-for-neural-differential-equations/20000)

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**Author:** [@MikeInnes](https://discourse.julialang.org/u/MikeInnes)\
**Replies:** 1\
**Last updated:** [January 24, 2019, 6:40am UTC](https://discourse.julialang.org/t/diffeqflux-jl-a-julia-library-for-neural-differential-equations/20000 "2019-01-24T06:40:42Z")

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We just released a new blog post showing how you can replicate the results of the recent Neural ODEs paper – and then some – using Flux and DifferentialEquations.jl. We’ve been combining ML and DiffEqs for a quite some t…

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## [Convert a JuMPArray in PowerModels](https://discourse.julialang.org/t/convert-a-jumparray-in-powermodels/19947)

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**Author:** [@Rasoul](https://discourse.julialang.org/u/Rasoul)\
**Replies:** 6\
**Last updated:** [January 24, 2019, 3:41am UTC](https://discourse.julialang.org/t/convert-a-jumparray-in-powermodels/19947 "2019-01-24T03:41:30Z")

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Hi All, I have the following piece of code in PowerModels that does some post processing procedures. It works perfectly for small test systems. aa = getvalue(var(pm, :cs)) bpp = Dict( (parse(Int,i), branch\["f\_bus"\] ,…

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## [What does \`Flux.@treelike\` do?](https://discourse.julialang.org/t/what-does-flux-treelike-do/19975)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 2\
**Last updated:** [January 24, 2019, 3:24am UTC](https://discourse.julialang.org/t/what-does-flux-treelike-do/19975 "2019-01-24T03:24:12Z")

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What does Flux.@treelike do? In Flux’s source code, I see a lot of Flux’s layers are defined and then @treelike is called. .E.g. @treelike Dense.

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## [Multi-dimensional SharedArrays.jl don't work in @distributed loops](https://discourse.julialang.org/t/multi-dimensional-sharedarrays-jl-dont-work-in-distributed-loops/19944)

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**Author:** [@michaelkyu](https://discourse.julialang.org/u/michaelkyu)\
**Replies:** 2\
**Last updated:** [January 23, 2019, 4:04pm UTC](https://discourse.julialang.org/t/multi-dimensional-sharedarrays-jl-dont-work-in-distributed-loops/19944 "2019-01-23T16:04:12Z")

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I’m following the documentation for parallel code in Julia v1.0. The simple example in the docs for using a 1D SharedArrays and @distributed does execute correctly for me. However, if I modify the example to make the Sha…

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## [Julia 0.6 parallelization of modules and functions](https://discourse.julialang.org/t/julia-0-6-parallelization-of-modules-and-functions/19952)

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**Author:** [@wonderboy3489](https://discourse.julialang.org/u/wonderboy3489)\
**Replies:** 2\
**Last updated:** [January 23, 2019, 4:00pm UTC](https://discourse.julialang.org/t/julia-0-6-parallelization-of-modules-and-functions/19952 "2019-01-23T16:00:13Z")

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Hi all, I’m trying to modify some example code from the documentation and am running into an error. Here’s my module that I’m trying to create: @everywhere module parallel\_test using Base.Distributed @everywhere using…

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## [Ipopt in Julia without JumP and automatic hessian calculation?](https://discourse.julialang.org/t/ipopt-in-julia-without-jump-and-automatic-hessian-calculation/19931)

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**Author:** [@Roshan.Sharma](https://discourse.julialang.org/u/Roshan.Sharma)\
**Replies:** 5\
**Last updated:** [January 23, 2019, 3:28pm UTC](https://discourse.julialang.org/t/ipopt-in-julia-without-jump-and-automatic-hessian-calculation/19931 "2019-01-23T15:28:21Z")

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Hi all, I know that it is possible to use Ipopt in Julia without using JumP. For this the user has to define eval\_f (objective function), eval\_g (nonlinear constraints), eval\_grad\_f (gradient of the objective function) …

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## [Color choices for graphs?](https://discourse.julialang.org/t/color-choices-for-graphs/19971)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 2\
**Last updated:** [January 23, 2019, 3:06pm UTC](https://discourse.julialang.org/t/color-choices-for-graphs/19971 "2019-01-23T15:06:32Z")

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I’m looking into presenting som model structures using graphs. Below is an example of a first attempt: My problem is related to choice of colors for ease of readability: Is there some guideline for best choice of li…

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## [Open Cascade - PythonOCC - 3D modelling](https://discourse.julialang.org/t/open-cascade-pythonocc-3d-modelling/19974)

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**Author:** [@josemaria](https://discourse.julialang.org/u/josemaria)\
**Replies:** 0\
**Last updated:** [January 23, 2019, 11:02am UTC](https://discourse.julialang.org/t/open-cascade-pythonocc-3d-modelling/19974 "2019-01-23T11:02:30Z")

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I was wondering if there is something equivalent to pythonooc. It wraps Open Cascade Community Edition. It seems that Open Cascade is what is behind FreeCAD. If there is nothing already done, I wonder if there is someth…

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## [Deploy Julia model in flask](https://discourse.julialang.org/t/deploy-julia-model-in-flask/19961)

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**Author:** [@VINITPANDEY](https://discourse.julialang.org/u/VINITPANDEY)\
**Replies:** 0\
**Last updated:** [January 23, 2019, 5:36am UTC](https://discourse.julialang.org/t/deploy-julia-model-in-flask/19961 "2019-01-23T05:36:05Z")

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How to deploy machine learning model in Julia

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## [Julia performs poorly on group-by benchmarks](https://discourse.julialang.org/t/julia-performs-poorly-on-group-by-benchmarks/16476)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 48\
**Last updated:** [January 23, 2019, 2:57am UTC](https://discourse.julialang.org/t/julia-performs-poorly-on-group-by-benchmarks/16476 "2019-01-23T02:57:58Z")

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h20 has published a set of benchmarks that shows Julia’s DataFrames.jl has, in general, the worst group-by performance out of many data packages. JuliaDB.jl was not benchmarked so that may be a good addition. I have done…

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## [Anybody working on Automatic Differentiation "the Conal Elliot way"?](https://discourse.julialang.org/t/anybody-working-on-automatic-differentiation-the-conal-elliot-way/19887)

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**Author:** [@jbrea](https://discourse.julialang.org/u/jbrea)\
**Replies:** 5\
**Last updated:** [January 23, 2019, 12:11am UTC](https://discourse.julialang.org/t/anybody-working-on-automatic-differentiation-the-conal-elliot-way/19887 "2019-01-23T00:11:28Z")

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Just learned about The simple essence of automatic differentiation. Did somebody already try to implement these ideas in Julia? Any thoughts about pros and cons of this approach relative to e.g. Zygote.jl?

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## [Are certain operations just not good candidates for threading?](https://discourse.julialang.org/t/are-certain-operations-just-not-good-candidates-for-threading/19909)

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**Author:** [@colintbowers](https://discourse.julialang.org/u/colintbowers)\
**Replies:** 4\
**Last updated:** [January 22, 2019, 11:51pm UTC](https://discourse.julialang.org/t/are-certain-operations-just-not-good-candidates-for-threading/19909 "2019-01-22T23:51:43Z")

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Hi all, I was experimenting with using threading to speed up a loop over vcat that swaps the first and second half of a sequence of vectors. I fire up Julia and verify: julia\> Threads.nthreads() 4 I wrote the followin…

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## [Using GLM.jl for mixed design Anova](https://discourse.julialang.org/t/using-glm-jl-for-mixed-design-anova/19922)

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**Author:** [@jbrea](https://discourse.julialang.org/u/jbrea)\
**Replies:** 4\
**Last updated:** [January 22, 2019, 9:58pm UTC](https://discourse.julialang.org/t/using-glm-jl-for-mixed-design-anova/19922 "2019-01-22T21:58:29Z")

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Is it possible to get with GLM.jl and ANOVA.jl something equivalent to R’s aov(data ~ age\*day + Error(id/day), data = data) to study data with one between (age) and one within (day) factor? I am stuck with translating…

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## [MNIST GPU CuArrays error](https://discourse.julialang.org/t/mnist-gpu-cuarrays-error/19695)

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**Author:** [@Fadi\_Nader](https://discourse.julialang.org/u/Fadi_Nader)\
**Replies:** 23\
**Last updated:** [January 22, 2019, 3:06pm UTC](https://discourse.julialang.org/t/mnist-gpu-cuarrays-error/19695 "2019-01-22T15:06:40Z")

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Hi, I’m trying to train MNIST over GPU using julia, but I face the following error. here is my code: X = hcat(float.(reshape.(imgs, :))...) |\>gpu; Y = onehotbatch(labels, 0:9) |\> gpu; batches=\[(X\[:,:,:,i\],Y\[:,i\]) for i…

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## [Delete a JuMP model entirely](https://discourse.julialang.org/t/delete-a-jump-model-entirely/19895)

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**Author:** [@Rasoul](https://discourse.julialang.org/u/Rasoul)\
**Replies:** 2\
**Last updated:** [January 22, 2019, 2:43pm UTC](https://discourse.julialang.org/t/delete-a-jump-model-entirely/19895 "2019-01-22T14:43:42Z")

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Hi All, Is there any way to delete a JuMP model after solving it? I have to call a function repeatedly to solve my problem but after the first call, I get the following error for every single variable in the model. Plea…

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## [Help Couenne](https://discourse.julialang.org/t/help-couenne/16825)

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**Author:** [@muriloasouza](https://discourse.julialang.org/u/muriloasouza)\
**Replies:** 23\
**Last updated:** [January 22, 2019, 12:42pm UTC](https://discourse.julialang.org/t/help-couenne/16825 "2019-01-22T12:42:58Z")

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Hello, i’m using Couenne to solve a MINLP problem. It has been running for days now, and during this time, i keep getting messages like this: Cbc0010I After 26300 nodes, 3934 on tree, 1e+050 best solution, best possible…

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## [Working with posteriors](https://discourse.julialang.org/t/working-with-posteriors/19846)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 7\
**Last updated:** [January 22, 2019, 10:45am UTC](https://discourse.julialang.org/t/working-with-posteriors/19846 "2019-01-22T10:45:13Z")

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Finding that I am writing a lot of repetitive code, I am trying to rethink the way I work with posterior distributions (eg from MCMC). I can typically reduce most operations on posteriors to transformations, which opera…

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## [how to make julia install a curl that respects the proxy? ](https://discourse.julialang.org/t/how-to-make-julia-install-a-curl-that-respects-the-proxy/19891)

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**Author:** [@frankwillmore](https://discourse.julialang.org/u/frankwillmore)\
**Replies:** 2\
**Last updated:** [January 21, 2019, 11:46pm UTC](https://discourse.julialang.org/t/how-to-make-julia-install-a-curl-that-respects-the-proxy/19891 "2019-01-21T23:46:26Z")

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I’m building Julia 1.0.3 (and probably 0.7.0) for deployment on a KNL cluster which sits behind a proxy. Cross-compilation succeeds and julia repl runs, as long as there is no need to load dependencies (e.g. MPI) at run-…

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## [Knet issue](https://discourse.julialang.org/t/knet-issue/18355)

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**Author:** [@microlifecc](https://discourse.julialang.org/u/microlifecc)\
**Replies:** 3\
**Last updated:** [January 22, 2019, 1:35am UTC](https://discourse.julialang.org/t/knet-issue/18355 "2019-01-22T01:35:30Z")

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Hi Guys! I am trying to go through the tutorial here. But I am getting the error: Cannot find libknet8, please rerun Pkg.build("Knet"). Stacktrace: \[1\] im2col!(::Array{Float64,4}, ::Array{Float64,4}, ::Array{Float64…

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## [Casting, annotations and numeric types for CUDAnative](https://discourse.julialang.org/t/casting-annotations-and-numeric-types-for-cudanative/19853)

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**Author:** [@Alex\_Ellison](https://discourse.julialang.org/u/Alex_Ellison)\
**Replies:** 5\
**Last updated:** [January 21, 2019, 9:07pm UTC](https://discourse.julialang.org/t/casting-annotations-and-numeric-types-for-cudanative/19853 "2019-01-21T21:07:07Z")

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Hello, I’ve begun exploring the CUDAnative package which modest success. I’ve run into a couple of limitations. I wanted to allocate an array from within my kernel as is shown in some of the project examples. The first…

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