# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?page=482

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**Page:** 483

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## [Higher derivatives using ForwardDiff](https://discourse.julialang.org/t/higher-derivatives-using-forwarddiff/28814)

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**Author:** [@RJDennis](https://discourse.julialang.org/u/RJDennis)\
**Replies:** 8\
**Last updated:** [September 17, 2019, 10:46am UTC](https://discourse.julialang.org/t/higher-derivatives-using-forwarddiff/28814 "2019-09-17T10:46:30Z")

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Hi All, If I have a function, say, test(x) = x\[1\]^3\*log(x\[2\])\*sqrt(x\[3\]) then what is the best way to use ForwardDiff to compute higher-order partial derivatives of this function? I tried the following first\_d(x) = …

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## [Digamma not defined in JuMP nonlinear optimization](https://discourse.julialang.org/t/digamma-not-defined-in-jump-nonlinear-optimization/28824)

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**Author:** [@brwst](https://discourse.julialang.org/u/brwst)\
**Replies:** 2\
**Last updated:** [September 17, 2019, 2:00am UTC](https://discourse.julialang.org/t/digamma-not-defined-in-jump-nonlinear-optimization/28824 "2019-09-17T02:00:11Z")

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Hello all, I’m trying to familiarize myself with JuMP, especially in the context of using SpecialFunctions. I’m struggling with gamma() and lgamma() specifically, so I’ve tried to implement the simple example from JuMP…

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## [Draw polygon around scatterplot data?](https://discourse.julialang.org/t/draw-polygon-around-scatterplot-data/28729)

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**Author:** [@BioTurboNick](https://discourse.julialang.org/u/BioTurboNick)\
**Replies:** 6\
**Last updated:** [September 16, 2019, 3:29pm UTC](https://discourse.julialang.org/t/draw-polygon-around-scatterplot-data/28729 "2019-09-16T15:29:22Z")

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Is there any package or combination of packages that would let me draw a polygon around a region in scatterplot data? Even just pieces I could cobble something together from. The end goal is to use it to filter my point…

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## [Where does Julia provide the biggest benefits over other ML frameworks for research?](https://discourse.julialang.org/t/where-does-julia-provide-the-biggest-benefits-over-other-ml-frameworks-for-research/28481)

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**Author:** [@Chillee](https://discourse.julialang.org/u/Chillee)\
**Replies:** 34\
**Last updated:** [September 16, 2019, 11:55am UTC](https://discourse.julialang.org/t/where-does-julia-provide-the-biggest-benefits-over-other-ml-frameworks-for-research/28481 "2019-09-16T11:55:30Z")

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I’ve read a bunch of the blogs on the Julia website (e.g. on machine learning and programming languages), but I remain unconvinced about what large benefits Julia provides over PyTorch. For example, one section in the b…

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## [Extracting local sensitivities when using save\_idxs](https://discourse.julialang.org/t/extracting-local-sensitivities-when-using-save-idxs/28714)

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**Author:** [@moesphere](https://discourse.julialang.org/u/moesphere)\
**Replies:** 5\
**Last updated:** [September 16, 2019, 8:05am UTC](https://discourse.julialang.org/t/extracting-local-sensitivities-when-using-save-idxs/28714 "2019-09-16T08:05:40Z")

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When specifying the saveat keyword, the extraction of local sensitivites seems to fail. The example is from the official documentation: using DifferentialEquations using DiffEqSensitivity function f(du,u,p,t) du\[1\] =…

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## [JDF - an experimental DataFrame serialization format is ready for beta testing](https://discourse.julialang.org/t/jdf-an-experimental-dataframe-serialization-format-is-ready-for-beta-testing/28722)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 8\
**Last updated:** [September 15, 2019, 11:01pm UTC](https://discourse.julialang.org/t/jdf-an-experimental-dataframe-serialization-format-is-ready-for-beta-testing/28722 "2019-09-15T23:01:56Z")

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https://github.com/xiaodaigh/JDF.jl I wanted to contribute to Parquet.jl and Arrow.jl but don’t feel confident that I know enough about serialization and disk formats. And reading the Parquet and Arrow docs still leaves…

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## [Animation error Makie](https://discourse.julialang.org/t/animation-error-makie/18405)

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**Author:** [@OlivierHnt](https://discourse.julialang.org/u/OlivierHnt)\
**Replies:** 15\
**Last updated:** [September 15, 2019, 4:04pm UTC](https://discourse.julialang.org/t/animation-error-makie/18405 "2019-09-15T16:04:51Z")

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I downloaded Makie and I tried to run one of the given example: using Makie xyvec = rand(Point2f0, (2)) .\* 5 .+ 1 velvec = rand(Point2f0, (2)) .\* 10 # define some other parameters t = 0 ts = 0.03 balldiameter = 1…

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## [Queryverse: How to @select columns with specific eltype? (using \`oftype\` function)](https://discourse.julialang.org/t/queryverse-how-to-select-columns-with-specific-eltype-using-oftype-function/28709)

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**Author:** [@Anselm\_Jeong](https://discourse.julialang.org/u/Anselm_Jeong)\
**Replies:** 3\
**Last updated:** [September 14, 2019, 10:14am UTC](https://discourse.julialang.org/t/queryverse-how-to-select-columns-with-specific-eltype-using-oftype-function/28709 "2019-09-14T10:14:47Z")

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Dear all Queryverse users. In an auxilary package QueryOperators.NamedTupleUtilities, there is a helper function named oftype. I guess it is related with selecting columns with specific eltype. But I cannot figure out h…

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## [How to call some special functions in julia v0.6?](https://discourse.julialang.org/t/how-to-call-some-special-functions-in-julia-v0-6/5127)

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**Author:** [@BVPs](https://discourse.julialang.org/u/BVPs)\
**Replies:** 5\
**Last updated:** [September 14, 2019, 5:56am UTC](https://discourse.julialang.org/t/how-to-call-some-special-functions-in-julia-v0-6/5127 "2019-09-14T05:56:10Z")

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Hello. Apparently, some of the special functions are moved to SpecialFunctions.jl in julia v0.6, e.g., besselj0. When I call this function, it generates the following warning: julia\> using SpecialFunctions julia\> x=0.01…

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## [Text Classification with Word Embeddings using Flux](https://discourse.julialang.org/t/text-classification-with-word-embeddings-using-flux/28751)

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**Author:** [@Nigel\_Adams](https://discourse.julialang.org/u/Nigel_Adams)\
**Replies:** 2\
**Last updated:** [September 14, 2019, 3:09am UTC](https://discourse.julialang.org/t/text-classification-with-word-embeddings-using-flux/28751 "2019-09-14T03:09:50Z")

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I’ve been experimenting with text classification using word embeddings and Flux. The posts start simple and work their way up to a project using 1d Convolutions. I couldn’t find many Julia examples on the web in this a…

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## [How to compute partial derivatives efficiently with Zygote](https://discourse.julialang.org/t/how-to-compute-partial-derivatives-efficiently-with-zygote/28731)

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**Author:** [@SEA](https://discourse.julialang.org/u/SEA)\
**Replies:** 2\
**Last updated:** [September 13, 2019, 7:23pm UTC](https://discourse.julialang.org/t/how-to-compute-partial-derivatives-efficiently-with-zygote/28731 "2019-09-13T19:23:38Z")

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Suppose we have a function f(x, y), and want to compute \\partial\_x f(x,y) for many y’s, ideally using no memory allocation. Using Zygote, I tried Zygote.forwarddiff(y-\>f(x,y), y). However, I believe this creates a new a…

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## [Problem with GPU programming](https://discourse.julialang.org/t/problem-with-gpu-programming/28704)

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**Author:** [@sergevic](https://discourse.julialang.org/u/sergevic)\
**Replies:** 4\
**Last updated:** [September 13, 2019, 4:09pm UTC](https://discourse.julialang.org/t/problem-with-gpu-programming/28704 "2019-09-13T16:09:20Z")

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I have the following code that I can run on Julia v.1.1: using LinearAlgebra L=Symmetric(rand(Float32,10000,10000)) C=zeros(Float32,size(L,1),size(L,2)) D=zeros(Float32,size(L,1),size(L,2)) D\[1,1\]=1 k=750 function Lap…

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## [Nonlinear equations on abstract vectors?](https://discourse.julialang.org/t/nonlinear-equations-on-abstract-vectors/28692)

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**Author:** [@tobydriscoll](https://discourse.julialang.org/u/tobydriscoll)\
**Replies:** 8\
**Last updated:** [September 12, 2019, 8:52pm UTC](https://discourse.julialang.org/t/nonlinear-equations-on-abstract-vectors/28692 "2019-09-12T20:52:23Z")

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I need to solve a (smooth, unconstrained) system of nonlinear equations for an unknown defined on multiple subdomains (to wit, domain decomposition for a PDE). A natural representation of the unknown might be a vector of…

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## [How do you guys would plot and histogram this Distribution F code?](https://discourse.julialang.org/t/how-do-you-guys-would-plot-and-histogram-this-distribution-f-code/28675)

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**Author:** [@Halor](https://discourse.julialang.org/u/Halor)\
**Replies:** 3\
**Last updated:** [September 12, 2019, 7:29pm UTC](https://discourse.julialang.org/t/how-do-you-guys-would-plot-and-histogram-this-distribution-f-code/28675 "2019-09-12T19:29:28Z")

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Hi. I am a new user in programming and in statistics so I want to learn all the things that I can. I try to code a PDF of F Distribution which formula have taken from Wikipedia (Distribución F - Wikipedia, la encicloped…

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## [ApproxFun: defining a nonlinear differential operator](https://discourse.julialang.org/t/approxfun-defining-a-nonlinear-differential-operator/15296)

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**Author:** [@zdenek\_hurak](https://discourse.julialang.org/u/zdenek_hurak)\
**Replies:** 6\
**Last updated:** [September 12, 2019, 12:44pm UTC](https://discourse.julialang.org/t/approxfun-defining-a-nonlinear-differential-operator/15296 "2019-09-12T12:44:11Z")

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Hello, I am struggling with the very basics of usage of ApproxFun package. I would like to define a nonlinear differential operator (the ultimate motivation is actually to define and solve a nonlinear ODE). The operator \\…

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## [Conditional logit regression -solved using cox regression](https://discourse.julialang.org/t/conditional-logit-regression-solved-using-cox-regression/28615)

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**Author:** [@compleat](https://discourse.julialang.org/u/compleat)\
**Replies:** 11\
**Last updated:** [September 12, 2019, 11:52am UTC](https://discourse.julialang.org/t/conditional-logit-regression-solved-using-cox-regression/28615 "2019-09-12T11:52:47Z")

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I noticed on here a thread which can’t now find about conditional/multinomial logit. Actually, there is no need to implement anything new - this is trivial if cox proportional hazards regression exists and allows for l…

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## [How to do batching in Flux's recurrent sequence model to take advantage of GPU during training?](https://discourse.julialang.org/t/how-to-do-batching-in-fluxs-recurrent-sequence-model-to-take-advantage-of-gpu-during-training/28678)

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**Author:** [@Azamat](https://discourse.julialang.org/u/Azamat)\
**Replies:** 1\
**Last updated:** [September 12, 2019, 10:37am UTC](https://discourse.julialang.org/t/how-to-do-batching-in-fluxs-recurrent-sequence-model-to-take-advantage-of-gpu-during-training/28678 "2019-09-12T10:37:38Z")

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Suppose I have a recurrent model in Flux, say using Flux D = 2 m = RNN(D,3) If want to apply it to sequence, then the documentation says I should represent my sequence seq as a vector of vectors, so something like T =…

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## [VegaLite.jl: render as raw image](https://discourse.julialang.org/t/vegalite-jl-render-as-raw-image/28645)

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**Author:** [@jtackm](https://discourse.julialang.org/u/jtackm)\
**Replies:** 8\
**Last updated:** [September 12, 2019, 10:12am UTC](https://discourse.julialang.org/t/vegalite-jl-render-as-raw-image/28645 "2019-09-12T10:12:17Z")

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I ran into a problem when using VegaLite (+Jupyter) on larger datasets (80k+ rows, 6 variables). When rendering a scatterplot inline in a notebook, jupyter hangs when saving. This is a MWE: df = DataFrame(\[Symbol("var$i…

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## [\[ANN\] Turing.jl Breaking Changes](https://discourse.julialang.org/t/ann-turing-jl-breaking-changes/28493)

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**Author:** [@cpfiffer](https://discourse.julialang.org/u/cpfiffer)\
**Replies:** 1\
**Last updated:** [September 12, 2019, 8:23am UTC](https://discourse.julialang.org/t/ann-turing-jl-breaking-changes/28493 "2019-09-12T08:23:55Z")

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Hey folks. Over the past couple months we’ve been working on a fairly significant PR designed to overhaul Turing’s internal API to make future development a lot easier. Many of these changes are never something a use wi…

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## [F Distribution, Beta function](https://discourse.julialang.org/t/f-distribution-beta-function/28630)

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**Author:** [@Halor](https://discourse.julialang.org/u/Halor)\
**Replies:** 7\
**Last updated:** [September 12, 2019, 2:26am UTC](https://discourse.julialang.org/t/f-distribution-beta-function/28630 "2019-09-12T02:26:43Z")

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Hi. I am new in this programming world so I need help for coding a F Distribution, due to I do not have idea to do this. I am having trouble even programming beta function. I just need some ideas so I would be able to d…

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## [How's AutoGrad different from Flux](https://discourse.julialang.org/t/hows-autograd-different-from-flux/28666)

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**Author:** [@stochastic\_guy](https://discourse.julialang.org/u/stochastic_guy)\
**Replies:** 0\
**Last updated:** [September 11, 2019, 9:04pm UTC](https://discourse.julialang.org/t/hows-autograd-different-from-flux/28666 "2019-09-11T21:04:02Z")

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Is there any difference between AutoGrad.jl and Flux’s automatic differentiation utilities?

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## [Where can I find the most widely adopted implementation of Legendre polynomials?](https://discourse.julialang.org/t/where-can-i-find-the-most-widely-adopted-implementation-of-legendre-polynomials/4183)

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**Author:** [@krcools](https://discourse.julialang.org/u/krcools)\
**Replies:** 17\
**Last updated:** [September 11, 2019, 4:59pm UTC](https://discourse.julialang.org/t/where-can-i-find-the-most-widely-adopted-implementation-of-legendre-polynomials/4183 "2019-09-11T16:59:33Z")

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Apart from an implementation hidden somewhere in Jacobi, I could not find where this special, but quite common, function was implemented. Am I missing the obvious location? Maybe it belongs in SpecialFunctions?

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## [Corrplot fails](https://discourse.julialang.org/t/corrplot-fails/28639)

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**Author:** [@moesphere](https://discourse.julialang.org/u/moesphere)\
**Replies:** 2\
**Last updated:** [September 11, 2019, 1:25pm UTC](https://discourse.julialang.org/t/corrplot-fails/28639 "2019-09-11T13:25:56Z")

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I am trying to plot data with corrplot(). It works for certain data, but fails for other data, i.e. no error is thrown but the plotting does not finish either. See the following minimal example: using StatsPlots A = \[3.…

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## [How to mark specific points in a contour plot using plots.jl?](https://discourse.julialang.org/t/how-to-mark-specific-points-in-a-contour-plot-using-plots-jl/28616)

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**Author:** [@tiago](https://discourse.julialang.org/u/tiago)\
**Replies:** 2\
**Last updated:** [September 11, 2019, 7:51am UTC](https://discourse.julialang.org/t/how-to-mark-specific-points-in-a-contour-plot-using-plots-jl/28616 "2019-09-11T07:51:29Z")

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Hello, As the title of the post says, I want to mark specific points in a contour plot in a similar way that we do in a normal plot, like in the picture below The code that generated the plot: plot(x,xV,title="Solut…

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## [How to implement interactive plots in IJulia](https://discourse.julialang.org/t/how-to-implement-interactive-plots-in-ijulia/9284)

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**Author:** [@mbaz](https://discourse.julialang.org/u/mbaz)\
**Replies:** 11\
**Last updated:** [September 10, 2019, 6:04pm UTC](https://discourse.julialang.org/t/how-to-implement-interactive-plots-in-ijulia/9284 "2019-09-10T18:04:07Z")

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I am trying to get interactive plots with Gaston in IJulia notebooks. I am almost there, but there is one final piece of the puzzle that I can’t quite figure out. I have this code in a notebook: using Gaston, Reactive, …

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## [How to quickly bulk insert into postgres](https://discourse.julialang.org/t/how-to-quickly-bulk-insert-into-postgres/15194)

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**Author:** [@ExpandingMan](https://discourse.julialang.org/u/ExpandingMan)\
**Replies:** 14\
**Last updated:** [September 10, 2019, 1:03pm UTC](https://discourse.julialang.org/t/how-to-quickly-bulk-insert-into-postgres/15194 "2019-09-10T13:03:48Z")

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This is sort of a shot in the dark, I don’t have any reason to believe there’s a better solution to this but I thought I’d give it a try. I’m trying to insert data into tables on a postgres database. I’m using the exce…

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## [Federated Learning in Julia](https://discourse.julialang.org/t/federated-learning-in-julia/28535)

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**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 8\
**Last updated:** [September 10, 2019, 11:37am UTC](https://discourse.julialang.org/t/federated-learning-in-julia/28535 "2019-09-10T11:37:36Z")

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Is anyone working with federated learning in Julia? Asking for a friend.

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## [Lagrange multipliers (duals) in JuMP 0.19](https://discourse.julialang.org/t/lagrange-multipliers-duals-in-jump-0-19/28328)

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**Author:** [@ko56](https://discourse.julialang.org/u/ko56)\
**Replies:** 15\
**Last updated:** [September 9, 2019, 6:06pm UTC](https://discourse.julialang.org/t/lagrange-multipliers-duals-in-jump-0-19/28328 "2019-09-09T18:06:59Z")

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I have Julia 1.1.1 and JuMP 0.19. I am solving a concave maximization problem with linear constraints with Ipopt. I am confused with what is happening to the signs of the Lagrange multipliers: The correct multipliers a…

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## [How can I handle uuid and jsob in PGSQL](https://discourse.julialang.org/t/how-can-i-handle-uuid-and-jsob-in-pgsql/28539)

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**Author:** [@hasanOryx](https://discourse.julialang.org/u/hasanOryx)\
**Replies:** 4\
**Last updated:** [September 9, 2019, 5:35pm UTC](https://discourse.julialang.org/t/how-can-i-handle-uuid-and-jsob-in-pgsql/28539 "2019-09-09T17:35:28Z")

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In my database, I’ve the below structure: CREATE TABLE public.devices ( id uuid, data jsonb ) When I run my query using this package, I got the below, how can I read the output properly?

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## [Bar chart with rotated x label for each bar](https://discourse.julialang.org/t/bar-chart-with-rotated-x-label-for-each-bar/28554)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 5\
**Last updated:** [September 9, 2019, 5:32pm UTC](https://discourse.julialang.org/t/bar-chart-with-rotated-x-label-for-each-bar/28554 "2019-09-09T17:32:38Z")

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I’m having a hard time plotting a simple bar chart with Plots.jl that has a label below each bar. The data are stored in a DataFrame that looks like this: julia\> merged\[:, \[1,5,6\]\] 85×3 DataFrame │ Row │ naics │ % of to…

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