# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=309

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**Page:** 310

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## [Need some help with FluxOpt](https://discourse.julialang.org/t/need-some-help-with-fluxopt/74904)

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**Author:** [@stochastic\_guy](https://discourse.julialang.org/u/stochastic_guy)\
**Replies:** 1\
**Last updated:** [January 20, 2022, 6:59pm UTC](https://discourse.julialang.org/t/need-some-help-with-fluxopt/74904 "2022-01-20T18:59:36Z")

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I am trying to use the FluxOptTools (https://github.com/baggepinnen/FluxOptTools.jl) to train a Flux model using Optim . I followed the example provided in the readme. It is working as intended. But when I slightly chang…

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## [Zygote terribly slow. What am I doing wrong?](https://discourse.julialang.org/t/zygote-terribly-slow-what-am-i-doing-wrong/74877)

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**Author:** [@shiroghost](https://discourse.julialang.org/u/shiroghost)\
**Replies:** 12\
**Last updated:** [January 19, 2022, 10:39pm UTC](https://discourse.julialang.org/t/zygote-terribly-slow-what-am-i-doing-wrong/74877 "2022-01-19T22:39:18Z")

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Hi all, I have been using ReverseDiff.jl for a project for quite some time. Now I have switched to Zygote because I need to determine derivative w.r.t. custom types and this seems straightforward with Zygote (see Evalua…

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## [Ssh cluster julia host address issue](https://discourse.julialang.org/t/ssh-cluster-julia-host-address-issue/63814)

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**Author:** [@grandemundo82](https://discourse.julialang.org/u/grandemundo82)\
**Replies:** 7\
**Last updated:** [January 19, 2022, 10:09pm UTC](https://discourse.julialang.org/t/ssh-cluster-julia-host-address-issue/63814 "2022-01-19T22:09:06Z")

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I am getting some error adding processors to a university cluster. When I ssh to the cluster and start Julia, when I run using Distributed addprocs(\[("username@compute-6-300",1)\], tunnel=true, max\_parallel=1, exename="…

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## [How to give a parameter list to Gurobi](https://discourse.julialang.org/t/how-to-give-a-parameter-list-to-gurobi/74878)

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**Author:** [@fksayaci](https://discourse.julialang.org/u/fksayaci)\
**Replies:** 4\
**Last updated:** [January 19, 2022, 9:25pm UTC](https://discourse.julialang.org/t/how-to-give-a-parameter-list-to-gurobi/74878 "2022-01-19T21:25:57Z")

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Hi all, I use Gurobi to solve an optimization problem. I might need to try different Gurobi parameters. Currently, I write parameters and their values inside the model directly, like Expansion\_Model = Model(optimizer…

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## [Evaluate gradient (backpropagation) on a user defined type](https://discourse.julialang.org/t/evaluate-gradient-backpropagation-on-a-user-defined-type/74434)

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**Author:** [@shiroghost](https://discourse.julialang.org/u/shiroghost)\
**Replies:** 4\
**Last updated:** [January 19, 2022, 6:20pm UTC](https://discourse.julialang.org/t/evaluate-gradient-backpropagation-on-a-user-defined-type/74434 "2022-01-19T18:20:02Z")

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Hi all, I have the following problem. Given a function f(x::Vector) I know that I can evaluate the gradient using any AD package (In particular I use ReverseDiff.jl). What I need now is to evaluate the gradient on a cus…

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## [2D DFFT: wrong order along the second dimension](https://discourse.julialang.org/t/2d-dfft-wrong-order-along-the-second-dimension/74869)

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**Author:** [@Gregstrq](https://discourse.julialang.org/u/Gregstrq)\
**Replies:** 1\
**Last updated:** [January 19, 2022, 4:14pm UTC](https://discourse.julialang.org/t/2d-dfft-wrong-order-along-the-second-dimension/74869 "2022-01-19T16:14:36Z")

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Let us consider a 2D discrete fast Fourier transform of a separable function: using FFTW xs = collect(0.0:0.1:0.9) ys = xs zs = cos.(xs).^2\*sin.(ys') fzs = fft(zs) The result of 2D DFF transform of zs is On the oth…

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## [CatViews with Flux optimize!](https://discourse.julialang.org/t/catviews-with-flux-optimize/74759)

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**Author:** [@lineycroc](https://discourse.julialang.org/u/lineycroc)\
**Replies:** 4\
**Last updated:** [January 19, 2022, 3:35pm UTC](https://discourse.julialang.org/t/catviews-with-flux-optimize/74759 "2022-01-19T15:35:08Z")

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Flux’s update!(opt, x, x̄) function errors when x and x̄ are of type CatView with the following message: TypeError: in typeassert, expected Tuple{CatView{1, Float64}, CatView{1, Float64}, Vector{Float64}}, got a value o…

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## [Solving HJB PDE using deep learning](https://discourse.julialang.org/t/solving-hjb-pde-using-deep-learning/60639)

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**Author:** [@Honza9723](https://discourse.julialang.org/u/Honza9723)\
**Replies:** 16\
**Last updated:** [January 19, 2022, 4:44am UTC](https://discourse.julialang.org/t/solving-hjb-pde-using-deep-learning/60639 "2022-01-19T04:44:50Z")

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Dear All, sorry for bothering with a possibly stupid question. I would like to ask for some advice about solving the Hamilton-Jacobi-Bellman equation using deep learning. I am trying to solve an HJB equation of a simpl…

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## [Subset using symbol from function input](https://discourse.julialang.org/t/subset-using-symbol-from-function-input/74806)

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**Author:** [@Frankiewaang](https://discourse.julialang.org/u/Frankiewaang)\
**Replies:** 4\
**Last updated:** [January 19, 2022, 3:52am UTC](https://discourse.julialang.org/t/subset-using-symbol-from-function-input/74806 "2022-01-19T03:52:26Z")

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Hi Guys, I’m a newbie to use Julia for data manipulation. When I try to convert some of my Python Pandas code to Julia code, I got some problem. function remove\_outliers(data::DataFrame,variable::Symbol;lower=-Inf,upp…

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## [Issue with (2+1)D Diffusion Reaction PDE with DiffEqOperators.jl](https://discourse.julialang.org/t/issue-with-2-1-d-diffusion-reaction-pde-with-diffeqoperators-jl/74840)

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**Author:** [@ash](https://discourse.julialang.org/u/ash)\
**Replies:** 0\
**Last updated:** [January 19, 2022, 1:25am UTC](https://discourse.julialang.org/t/issue-with-2-1-d-diffusion-reaction-pde-with-diffeqoperators-jl/74840 "2022-01-19T01:25:47Z")

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I am studying a (2+1)D diffusion-reaction PDE. I have asked about this before and got plenty of help and that resolved my issues. However, I just realized I was getting the wrong results because the model should be in tw…

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## [Repeated indext at optimization problem in JuMP](https://discourse.julialang.org/t/repeated-indext-at-optimization-problem-in-jump/74295)

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**Author:** [@Yuri\_Mizusawa](https://discourse.julialang.org/u/Yuri_Mizusawa)\
**Replies:** 4\
**Last updated:** [January 18, 2022, 11:04pm UTC](https://discourse.julialang.org/t/repeated-indext-at-optimization-problem-in-jump/74295 "2022-01-18T23:04:56Z")

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Hi, I getting an error that says " Repeated index 1. Index sets must have unique elements." My problem has to be the following structure: x(1,0,0)+x(1,0,4)+x(1,4,0)+x(1,4,4)+x(2,0,0)+x(2,4,0)+x(2,6,0) Max I reduced o…

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## [Dash JSON3 error](https://discourse.julialang.org/t/dash-json3-error/74829)

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**Author:** [@Iulian.Cioarca](https://discourse.julialang.org/u/Iulian.Cioarca)\
**Replies:** 0\
**Last updated:** [January 18, 2022, 8:29pm UTC](https://discourse.julialang.org/t/dash-json3-error/74829 "2022-01-18T20:29:48Z")

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I recently updated to Julia 1.7.1 and along with it some packages. My previously working Dash app now crashes with the following error when I want to plot something: ┌ Error: error handling request │ exception = │ …

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## [How to animate a plot with subplots](https://discourse.julialang.org/t/how-to-animate-a-plot-with-subplots/74831)

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**Author:** [@thompsonmj](https://discourse.julialang.org/u/thompsonmj)\
**Replies:** 5\
**Last updated:** [January 18, 2022, 9:27pm UTC](https://discourse.julialang.org/t/how-to-animate-a-plot-with-subplots/74831 "2022-01-18T21:27:44Z")

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I’d like to make an animation of a figure with two subplots. using Plots x\_data = range(0.0,stop=2π, length=1000) y\_data = sin.(x\_data) .+ 0.1.\*randn(1000,100) @gif for i ∈ 1:100 fig = plot(layout = grid(2,1), leg…

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## [Refresh token in background](https://discourse.julialang.org/t/refresh-token-in-background/74830)

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**Author:** [@robertdj](https://discourse.julialang.org/u/robertdj)\
**Replies:** 0\
**Last updated:** [January 18, 2022, 8:40pm UTC](https://discourse.julialang.org/t/refresh-token-in-background/74830 "2022-01-18T20:40:27Z")

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I access a REST API that rely on a temporary token. The token is short lived, but does come with a refresh token. I store it in a struct like mutable struct MyToken AccessToken::String RefreshToken::String E…

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## [Combine Makie with GMT.jl](https://discourse.julialang.org/t/combine-makie-with-gmt-jl/74347)

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**Author:** [@filchristou](https://discourse.julialang.org/u/filchristou)\
**Replies:** 9\
**Last updated:** [January 18, 2022, 6:45pm UTC](https://discourse.julialang.org/t/combine-makie-with-gmt-jl/74347 "2022-01-18T18:45:22Z")

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Short story: I want to plot graphs on top of a map. Can I use GMT.jl to draw the region of interest and plot over it using GraphMakie.jl ? Long story: GraphMakie.jl Let’s say I want to plot the Abilene network. I ha…

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## [Plots: string interpolation in labels?](https://discourse.julialang.org/t/plots-string-interpolation-in-labels/10799)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 3\
**Last updated:** [January 18, 2022, 3:22pm UTC](https://discourse.julialang.org/t/plots-string-interpolation-in-labels/10799 "2022-01-18T15:22:35Z")

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I’m solving a differential equation several times where I vary a parameter, say Kp = linspace(1,5,5). The result is a vector of vectors (time series), say vec is a vector (1D array) of vectors (time series). I then want…

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## [Plots color based on discrete value](https://discourse.julialang.org/t/plots-color-based-on-discrete-value/72472)

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**Author:** [@JianghuiDu](https://discourse.julialang.org/u/JianghuiDu)\
**Replies:** 4\
**Last updated:** [January 18, 2022, 10:40am UTC](https://discourse.julialang.org/t/plots-color-based-on-discrete-value/72472 "2022-01-18T10:40:38Z")

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data = DataFrame(x=1:5,y=1:5,color=\["a","a","b","a","c"\]) using StatsPlots @df data scatter(:x,:y) How can add color to the plot using the discrete value of column :color automatically? In ggplot I can do something lik…

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## [Several questions about KernelAbstractions](https://discourse.julialang.org/t/several-questions-about-kernelabstractions/74740)

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**Author:** [@fedoroff](https://discourse.julialang.org/u/fedoroff)\
**Replies:** 6\
**Last updated:** [January 18, 2022, 7:54am UTC](https://discourse.julialang.org/t/several-questions-about-kernelabstractions/74740 "2022-01-18T07:54:55Z")

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Hello, I have several questions about KernelAbstractions package: What is the current status of KernelAbstractions in the Julia GPU ecosystem? Is it being seen as an exploration package to try out some possible direc…

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## [CSV.jl skipto and limit keyword arguments](https://discourse.julialang.org/t/csv-jl-skipto-and-limit-keyword-arguments/74780)

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**Author:** [@xinchin](https://discourse.julialang.org/u/xinchin)\
**Replies:** 8\
**Last updated:** [January 18, 2022, 7:39am UTC](https://discourse.julialang.org/t/csv-jl-skipto-and-limit-keyword-arguments/74780 "2022-01-18T07:39:29Z")

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I have another problem with CSV.jl and DataFrames.jl, again I figure out the problem is due to skipto/limit keyword in CSV, since I encounter a problem a day (I haven’t reported all of them but will do it from now on) my…

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## [Adding nonlinear constraints in JuMP without hard-coding](https://discourse.julialang.org/t/adding-nonlinear-constraints-in-jump-without-hard-coding/74626)

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**Author:** [@ReinhardMu](https://discourse.julialang.org/u/ReinhardMu)\
**Replies:** 4\
**Last updated:** [January 18, 2022, 1:38am UTC](https://discourse.julialang.org/t/adding-nonlinear-constraints-in-jump-without-hard-coding/74626 "2022-01-18T01:38:28Z")

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Hi, I am trying to do some kind of cutting-plan algorithm in JuMP. I currently have the following example: function generate\_model(ydisc :: Vector{Vector{Float64}}) model = Model(SCIP.Optimizer) @variable(mod…

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## [Plotting from within a loop using GR?](https://discourse.julialang.org/t/plotting-from-within-a-loop-using-gr/4435)

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**Author:** [@zorp](https://discourse.julialang.org/u/zorp)\
**Replies:** 8\
**Last updated:** [January 17, 2022, 8:23pm UTC](https://discourse.julialang.org/t/plotting-from-within-a-loop-using-gr/4435 "2022-01-17T20:23:25Z")

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The following doesn’t produce any output using Juno and v0.6 of Julia: histogram(randn(10)) for i = 1:10 histogram!(randn(10)) end why is that?

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## [Design gear train with specific ratio with a set of fixed gears](https://discourse.julialang.org/t/design-gear-train-with-specific-ratio-with-a-set-of-fixed-gears/74675)

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**Author:** [@pepijndevos](https://discourse.julialang.org/u/pepijndevos)\
**Replies:** 7\
**Last updated:** [January 16, 2022, 10:35pm UTC](https://discourse.julialang.org/t/design-gear-train-with-specific-ratio-with-a-set-of-fixed-gears/74675 "2022-01-16T22:35:30Z")

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I want to make a gear train out of lego gears that needs a specific gear ratio. So let’s say I want a gear train with a ratio of 45/28 or whatever, and I have gears with \[8, 12, 16, 20, 24, 36, 40\] teeth. What combinatio…

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## [NeuralPDE.jl: how to use random noise as the initial condition](https://discourse.julialang.org/t/neuralpde-jl-how-to-use-random-noise-as-the-initial-condition/74723)

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**Author:** [@ash](https://discourse.julialang.org/u/ash)\
**Replies:** 3\
**Last updated:** [January 17, 2022, 5:22pm UTC](https://discourse.julialang.org/t/neuralpde-jl-how-to-use-random-noise-as-the-initial-condition/74723 "2022-01-17T17:22:26Z")

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I am trying to solve the same model discussed in this question using a PINN approach. Frankenstining together some code based on the examples in the documentation, I ended up with the following: using NeuralPDE, Flux, …

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## [Plots - reset color cycle](https://discourse.julialang.org/t/plots-reset-color-cycle/74751)

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**Author:** [@cripcate](https://discourse.julialang.org/u/cripcate)\
**Replies:** 7\
**Last updated:** [January 17, 2022, 12:41pm UTC](https://discourse.julialang.org/t/plots-reset-color-cycle/74751 "2022-01-17T12:41:17Z")

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Hi there. I have a plot with two different series (a scatterline and a fillrange). I want the fillrange (representing error) to be of the same color as the line. Here is my code: using DataFrames, Plots, Random Random.…

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## [Problem with using CSV package when set \`limit\` option](https://discourse.julialang.org/t/problem-with-using-csv-package-when-set-limit-option/74724)

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**Author:** [@xinchin](https://discourse.julialang.org/u/xinchin)\
**Replies:** 4\
**Last updated:** [January 17, 2022, 7:04am UTC](https://discourse.julialang.org/t/problem-with-using-csv-package-when-set-limit-option/74724 "2022-01-17T07:04:15Z")

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I get ArgumentError: Reference array points beyond the end of the pool when try to sort a data frame, now I know the problem is because I am using CSV.jl, but ideally this shouldn’t happen A minimal example to show the …

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## [Normal probability plot](https://discourse.julialang.org/t/normal-probability-plot/74663)

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**Author:** [@iskyd](https://discourse.julialang.org/u/iskyd)\
**Replies:** 7\
**Last updated:** [January 16, 2022, 12:54am UTC](https://discourse.julialang.org/t/normal-probability-plot/74663 "2022-01-16T00:54:36Z")

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I have a dataframe that contains SalePrice and I’m trying to plot the normal distribution and the normal probability plot. To plot the distribution I’m using Plots jl and StatsPlot and doing something like histogram(tr…

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## [Counting Graphlets or Motifs](https://discourse.julialang.org/t/counting-graphlets-or-motifs/74580)

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**Author:** [@Rasoul](https://discourse.julialang.org/u/Rasoul)\
**Replies:** 2\
**Last updated:** [January 17, 2022, 1:00am UTC](https://discourse.julialang.org/t/counting-graphlets-or-motifs/74580 "2022-01-17T01:00:22Z")

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Hello everybody, I will appreciate it if you let me know about the existence of a Julia package for counting graphlets or motifs in a graph. All the best, Rasoul

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## [Makie - Plotting hatched polygons in CairoMakie](https://discourse.julialang.org/t/makie-plotting-hatched-polygons-in-cairomakie/74682)

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**Author:** [@Pablo\_Marchant](https://discourse.julialang.org/u/Pablo_Marchant)\
**Replies:** 1\
**Last updated:** [January 16, 2022, 7:50pm UTC](https://discourse.julialang.org/t/makie-plotting-hatched-polygons-in-cairomakie/74682 "2022-01-16T19:50:20Z")

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Hi! I’m looking to reimplement various tools I have using python+matplotlib to julia+makie. Most of these deal with stellar astrophysics. One particular one is a plotting tool meant to post-process simulation data into …

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## [Difficulties with the step function](https://discourse.julialang.org/t/difficulties-with-the-step-function/74603)

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**Author:** [@sbacelar](https://discourse.julialang.org/u/sbacelar)\
**Replies:** 4\
**Last updated:** [January 16, 2022, 2:23pm UTC](https://discourse.julialang.org/t/difficulties-with-the-step-function/74603 "2022-01-16T14:23:01Z")

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Here I have a 6 X 3 array of agents. Each line has agents with the same age: the first line with age 20 and the last with age 25. I think I have no problems with the initialize function. But when I try to advance a step …

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## [Large - Scale Nonlinear Convex Optimization - Performance](https://discourse.julialang.org/t/large-scale-nonlinear-convex-optimization-performance/74676)

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**Author:** [@jmcastro2109](https://discourse.julialang.org/u/jmcastro2109)\
**Replies:** 8\
**Last updated:** [January 15, 2022, 9:50pm UTC](https://discourse.julialang.org/t/large-scale-nonlinear-convex-optimization-performance/74676 "2022-01-15T21:50:22Z")

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Hi everybody, I am trying to solve a large-scale nonlinear problem that is convex and has linear inequality constraints. There are 550 unknowns and 25000 linear inequality constraints. I want to get your recommendations …

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