# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=327

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**Page:** 328

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## [What is \`Base.allocatedinline\` and custom types for \`CuArray\` (\`CUDA.jl\`) involving \`Missing\`](https://discourse.julialang.org/t/what-is-base-allocatedinline-and-custom-types-for-cuarray-cuda-jl-involving-missing/70122)

<div class="topic-metadata">

**Author:** [@PaulVirally](https://discourse.julialang.org/u/PaulVirally)\
**Replies:** 3\
**Last updated:** [October 22, 2021, 8:24am UTC](https://discourse.julialang.org/t/what-is-base-allocatedinline-and-custom-types-for-cuarray-cuda-jl-involving-missing/70122 "2021-10-22T08:24:01Z")

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I am trying to pass an array of a custom type to the GPU using CUDA.jl. Here is a MWE: using CUDA struct MyStruct arr::Vector{Tuple{Int, Int}} end cpu\_arr = Vector{Union{Missing, MyStruct}} # Works as expected gpu…

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## [\[ANN\] MissingsAsFalse.jl: Treat missing as false in select operations](https://discourse.julialang.org/t/ann-missingsasfalse-jl-treat-missing-as-false-in-select-operations/70062)

<div class="topic-metadata">

**Author:** [@pdeffebach](https://discourse.julialang.org/u/pdeffebach)\
**Replies:** 1\
**Last updated:** [October 20, 2021, 3:27pm UTC](https://discourse.julialang.org/t/ann-missingsasfalse-jl-treat-missing-as-false-in-select-operations/70062 "2021-10-20T15:27:26Z")

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Hello everyone! I am pleased to announce the release of a new package: MissingsAsFalse.jl. As the name implies, it helps you write code where comparisons with missing are treated as false. Which is often what is needed i…

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## [Estimate posterior distribution of initial condition(s)](https://discourse.julialang.org/t/estimate-posterior-distribution-of-initial-condition-s/70139)

<div class="topic-metadata">

**Author:** [@vembha](https://discourse.julialang.org/u/vembha)\
**Replies:** 4\
**Last updated:** [October 21, 2021, 4:58pm UTC](https://discourse.julialang.org/t/estimate-posterior-distribution-of-initial-condition-s/70139 "2021-10-21T16:58:41Z")

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Hello, I understood how the defining of prior distributions to parameter values and estimating the posterior distributions works using Turing. But, I was wondering if there is a way to estimate the posterior distributio…

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## [\[ParallelStencil\] Boundary Conditions](https://discourse.julialang.org/t/parallelstencil-boundary-conditions/70171)

<div class="topic-metadata">

**Author:** [@apattyn](https://discourse.julialang.org/u/apattyn)\
**Replies:** 2\
**Last updated:** [October 22, 2021, 1:22am UTC](https://discourse.julialang.org/t/parallelstencil-boundary-conditions/70171 "2021-10-22T01:22:55Z")

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I was taking a look at the acoustic apps, and I was able to modify it to include a time-varying pressure source. However, I can’t quite figure out how to prevent back reflections from the boundary. Is it possible to m…

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## [Lyapunov Spectrum simple code problem](https://discourse.julialang.org/t/lyapunov-spectrum-simple-code-problem/70182)

<div class="topic-metadata">

**Author:** [@Gabriel\_Carita](https://discourse.julialang.org/u/Gabriel_Carita)\
**Replies:** 2\
**Last updated:** [October 22, 2021, 12:43am UTC](https://discourse.julialang.org/t/lyapunov-spectrum-simple-code-problem/70182 "2021-10-22T00:43:20Z")

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Hello there, I’m trying to figure out how to solve my lyapunov spectrum handwrite code using the QR method for a simple example (lorenz system), there is something wrong with my code ? I’m trying to reproduce the values…

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## [DifferentialEquations.jl and ReverseDiff.jl: MethodError: Cannot \`convert\` an object of type Vector{ReverseDiff.TrackedReal{](https://discourse.julialang.org/t/differentialequations-jl-and-reversediff-jl-methoderror-cannot-convert-an-object-of-type-vector-reversediff-trackedreal/70175)

<div class="topic-metadata">

**Author:** [@salazardetroya](https://discourse.julialang.org/u/salazardetroya)\
**Replies:** 1\
**Last updated:** [October 21, 2021, 7:43pm UTC](https://discourse.julialang.org/t/differentialequations-jl-and-reversediff-jl-methoderror-cannot-convert-an-object-of-type-vector-reversediff-trackedreal/70175 "2021-10-21T19:43:49Z")

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I am trying to get gradients in a heat equation solved with DifferentialEquations.jl: using DiffEqOperators, OrdinaryDiffEq, Plots, Zygote, DiffEqSensitivity nknots = 10 h = 1.0 / (nknots + 1) knots = range(h, step=h, …

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## [DiffEqOperators and gradients](https://discourse.julialang.org/t/diffeqoperators-and-gradients/70121)

<div class="topic-metadata">

**Author:** [@salazardetroya](https://discourse.julialang.org/u/salazardetroya)\
**Replies:** 2\
**Last updated:** [October 21, 2021, 4:00pm UTC](https://discourse.julialang.org/t/diffeqoperators-and-gradients/70121 "2021-10-21T16:00:05Z")

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I am trying to solve the following problem \\begin{aligned} \\nabla \\cdot \\nabla \\phi\_{1} &= \\frac{\\partial\\left(\\phi\_{1}-\\phi\_{2}\\right)}{\\partial t}\\\\ \\nabla \\cdot \\nabla \\phi\_{2} &= -\\tau p\_1p\_2\\frac{\\partial\\left(\\…

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## [Arrays of arrays and arrays of structures in CUDA kernels cause random errors](https://discourse.julialang.org/t/arrays-of-arrays-and-arrays-of-structures-in-cuda-kernels-cause-random-errors/69739)

<div class="topic-metadata">

**Author:** [@fedoroff](https://discourse.julialang.org/u/fedoroff)\
**Replies:** 21\
**Last updated:** [October 21, 2021, 2:21pm UTC](https://discourse.julialang.org/t/arrays-of-arrays-and-arrays-of-structures-in-cuda-kernels-cause-random-errors/69739 "2021-10-21T14:21:01Z")

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Hello, I want to pass an array of structures to CUDA kernel. Each structure contains an array of CuArrays. Most of the time my code works well, but sometimes randomly I see errors of the following type: ERROR: Out-of-…

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## [Julia in fusion research](https://discourse.julialang.org/t/julia-in-fusion-research/26460)

<div class="topic-metadata">

**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 10\
**Last updated:** [October 21, 2021, 1:18pm UTC](https://discourse.julialang.org/t/julia-in-fusion-research/26460 "2021-10-21T13:18:56Z")

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Following on fromn the discussion on PIC codes. Is there much activity in using Julia for fusion and plasma simulations? Any pointers gratefully received.

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## [Looking for MG solver for sparse matrix on GPU](https://discourse.julialang.org/t/looking-for-mg-solver-for-sparse-matrix-on-gpu/61347)

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**Author:** [@Ludovic\_Dumoulin](https://discourse.julialang.org/u/Ludovic_Dumoulin)\
**Replies:** 7\
**Last updated:** [October 21, 2021, 8:24am UTC](https://discourse.julialang.org/t/looking-for-mg-solver-for-sparse-matrix-on-gpu/61347 "2021-10-21T08:24:27Z")

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Hey, I’m looking for an algebraic multigrid solver that run on GPU. The AlgebraicMultigrid.jl package is not compatible with CUDA and I can’t find other package. I could use the AMGX library in Cuda and C++ but then I’l…

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## [How group nodes if a path exists between nodes?](https://discourse.julialang.org/t/how-group-nodes-if-a-path-exists-between-nodes/70127)

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**Author:** [@Manu\_Francis](https://discourse.julialang.org/u/Manu_Francis)\
**Replies:** 1\
**Last updated:** [October 21, 2021, 8:15am UTC](https://discourse.julialang.org/t/how-group-nodes-if-a-path-exists-between-nodes/70127 "2021-10-21T08:15:55Z")

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Hi, If I have some nodes coordinates and I have to group these nodes together if there is path exist between them. Is there any algorithm available? The graph structure looks like below: # Load the packages using Ligh…

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## [JuMP installation issue in Julia v1.6](https://discourse.julialang.org/t/jump-installation-issue-in-julia-v1-6/58721)

<div class="topic-metadata">

**Author:** [@erans](https://discourse.julialang.org/u/erans)\
**Replies:** 20\
**Last updated:** [October 20, 2021, 4:29pm UTC](https://discourse.julialang.org/t/jump-installation-issue-in-julia-v1-6/58721 "2021-10-20T16:29:07Z")

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Hello, Something rather strange just happened when I tried to use JuMP with Julia v1.6 and I’m curious if it’s a bug, or if I can get some explanation on why something like this would happen. (I hope this is the approp…

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## [Integer Optimization: performance help](https://discourse.julialang.org/t/integer-optimization-performance-help/67524)

<div class="topic-metadata">

**Author:** [@jmcastro2109](https://discourse.julialang.org/u/jmcastro2109)\
**Replies:** 11\
**Last updated:** [October 20, 2021, 10:10pm UTC](https://discourse.julialang.org/t/integer-optimization-performance-help/67524 "2021-10-20T22:10:50Z")

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Hello, I am working with an integer optimization problem and I am looking for ways to speed the code up. The math problem is the following I am sampling K different outcomes of the random variable \\omega^{k} which in t…

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## ['Stale File Handle' Error When Submitting Job Array on SLURM](https://discourse.julialang.org/t/stale-file-handle-error-when-submitting-job-array-on-slurm/70108)

<div class="topic-metadata">

**Author:** [@dleather](https://discourse.julialang.org/u/dleather)\
**Replies:** 1\
**Last updated:** [October 20, 2021, 9:20pm UTC](https://discourse.julialang.org/t/stale-file-handle-error-when-submitting-job-array-on-slurm/70108 "2021-10-20T21:20:48Z")

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I’m attempting to submit a large number of jobs on an HPC running SLURM. The code runs fine when submitting a single job at a time, but I am submitting 4000 jobs at once. The error is as follows: ERROR: SystemError: cl…

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## [JSON parsing gives error message with Dash](https://discourse.julialang.org/t/json-parsing-gives-error-message-with-dash/70104)

<div class="topic-metadata">

**Author:** [@stanlazic](https://discourse.julialang.org/u/stanlazic)\
**Replies:** 1\
**Last updated:** [October 20, 2021, 7:41pm UTC](https://discourse.julialang.org/t/json-parsing-gives-error-message-with-dash/70104 "2021-10-20T19:41:46Z")

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This code runs fine and JSON.parse() works as expected. using Dash using DataFrames using CSV using Base64 using JSON # example data data\_dict = Dict("group" =\> \["A", "A", "B", "B"\], "height" =\> \[1, 2,…

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## [Using callback during adjoint method for NeuralODE](https://discourse.julialang.org/t/using-callback-during-adjoint-method-for-neuralode/70076)

<div class="topic-metadata">

**Author:** [@xk\_y](https://discourse.julialang.org/u/xk_y)\
**Replies:** 4\
**Last updated:** [October 20, 2021, 6:16pm UTC](https://discourse.julialang.org/t/using-callback-during-adjoint-method-for-neuralode/70076 "2021-10-20T18:16:05Z")

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I am training a neural ode with a callback function to add a certain value at every integration timestep. The forward pass works but an error occur during backpropagation. I was wondering if the adjoint method supports a…

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## [CellmlToolkit.jl: How to get observables?](https://discourse.julialang.org/t/cellmltoolkit-jl-how-to-get-observables/69151)

<div class="topic-metadata">

**Author:** [@andreypikunov](https://discourse.julialang.org/u/andreypikunov)\
**Replies:** 3\
**Last updated:** [October 20, 2021, 2:19pm UTC](https://discourse.julialang.org/t/cellmltoolkit-jl-how-to-get-observables/69151 "2021-10-20T14:19:59Z")

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Hello! Using Beeler-Reuter model from the README I can list observables: julia\> ml = CellModel("models/beeler\_reuter\_1977.cellml.xml") julia\> observed(ml.sys) 39-element Vector{Equation}: slow\_inward\_current\_f\_gate₊V(…

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## [Object detection and Classification using PointCloud data in Julia?](https://discourse.julialang.org/t/object-detection-and-classification-using-pointcloud-data-in-julia/70097)

<div class="topic-metadata">

**Author:** [@DoktorMike](https://discourse.julialang.org/u/DoktorMike)\
**Replies:** 0\
**Last updated:** [October 20, 2021, 1:57pm UTC](https://discourse.julialang.org/t/object-detection-and-classification-using-pointcloud-data-in-julia/70097 "2021-10-20T13:57:10Z")

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I recently came across an interesting problem where I need to do object detection and classification in a 3D PointCloud. I found some implementations for a few networks in PyTorch but didn’t find any in Julia. Flux3D doe…

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## [Juliacon21-gpu\_workshop kernel abstractions heat diffusion](https://discourse.julialang.org/t/juliacon21-gpu-workshop-kernel-abstractions-heat-diffusion/70048)

<div class="topic-metadata">

**Author:** [@Ludovic\_Dumoulin](https://discourse.julialang.org/u/Ludovic_Dumoulin)\
**Replies:** 2\
**Last updated:** [October 20, 2021, 8:24am UTC](https://discourse.julialang.org/t/juliacon21-gpu-workshop-kernel-abstractions-heat-diffusion/70048 "2021-10-20T08:24:43Z")

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Hi, I am trying to reproduce the Juliacon21-gpu workshop and I am stuck at the last part of kernel abstractions. I wrote: @kernel function diffuse\_kabs\_lmem!(out, @Const(data), a, dt, dx, dy) i, j = @index(Global,…

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## [Type instability in ForwardDiff.gradient](https://discourse.julialang.org/t/type-instability-in-forwarddiff-gradient/68973)

<div class="topic-metadata">

**Author:** [@ElOceanografo](https://discourse.julialang.org/u/ElOceanografo)\
**Replies:** 8\
**Last updated:** [October 20, 2021, 12:04am UTC](https://discourse.julialang.org/t/type-instability-in-forwarddiff-gradient/68973 "2021-10-20T00:04:14Z")

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Working on a nested optimization problem, I noticed that a lot of time was being spent in gradient calls, and a little digging found that doing out-of-place gradients was introducing a type-instability. I followed the a…

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## [\[ParallelStencil\] Wave Equation](https://discourse.julialang.org/t/parallelstencil-wave-equation/70012)

<div class="topic-metadata">

**Author:** [@apattyn](https://discourse.julialang.org/u/apattyn)\
**Replies:** 2\
**Last updated:** [October 19, 2021, 9:07pm UTC](https://discourse.julialang.org/t/parallelstencil-wave-equation/70012 "2021-10-19T21:07:03Z")

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I was looking at ParallelStencil.jl, and trying to just use it to directly solve the second order form of the wave equation. I noticed in the 2D acoustic example that it is broken up into two first order equations, and I…

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## [Side effects of using keyword allowduplicates in the unstack function](https://discourse.julialang.org/t/side-effects-of-using-keyword-allowduplicates-in-the-unstack-function/70050)

<div class="topic-metadata">

**Author:** [@rocco\_sprmnt21](https://discourse.julialang.org/u/rocco_sprmnt21)\
**Replies:** 1\
**Last updated:** [October 19, 2021, 4:52pm UTC](https://discourse.julialang.org/t/side-effects-of-using-keyword-allowduplicates-in-the-unstack-function/70050 "2021-10-19T16:52:03Z")

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If I have this df df1 = DataFrame( field = repeat(\["A", "B", "C", "D", "E"\], 12), data = rand(60), group = repeat(1:4, outer = 15)) if i try to do the following i get the suggestion to…

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## [Converting Postman Prerequest Script to Julia Script](https://discourse.julialang.org/t/converting-postman-prerequest-script-to-julia-script/69832)

<div class="topic-metadata">

**Author:** [@bww00](https://discourse.julialang.org/u/bww00)\
**Replies:** 5\
**Last updated:** [October 19, 2021, 4:16pm UTC](https://discourse.julialang.org/t/converting-postman-prerequest-script-to-julia-script/69832 "2021-10-19T16:16:32Z")

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I would like to convert the following postman js script to julia http requests. We will then translate to a vendor supplied programming language. The Julia code would be used to validate the vendor supplied results Th…

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## [Weird PRNG behavior](https://discourse.julialang.org/t/weird-prng-behavior/63186)

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**Author:** [@palday](https://discourse.julialang.org/u/palday)\
**Replies:** 4\
**Last updated:** [October 19, 2021, 8:01am UTC](https://discourse.julialang.org/t/weird-prng-behavior/63186 "2021-10-19T08:01:30Z")

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It looks like randn!(rng, v) gives different values depending on the type not the eltype of v: julia\> using Random julia\> v1 = Vector{Float64}(undef, 200) julia\> m = Matrix{Float64}(undef, 200, 3) julia\> v2 = view(m, :,…

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## [Makie - Clipped heatmap](https://discourse.julialang.org/t/makie-clipped-heatmap/70014)

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**Author:** [@nandoconde](https://discourse.julialang.org/u/nandoconde)\
**Replies:** 4\
**Last updated:** [October 19, 2021, 7:55am UTC](https://discourse.julialang.org/t/makie-clipped-heatmap/70014 "2021-10-19T07:55:21Z")

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Hello! Is there a way to get a clipped heatmap in Makie? MWE would be: # Packages using GLMakie GLMakie.activate!() # Ranges a = -3:0.033:3 b = -3:0.033:3 # Function f(x,y) = (x\*y)/(1-abs(x+y)) # Plot \_fig = Figure(…

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## [Unicode support for other fonts in Plots](https://discourse.julialang.org/t/unicode-support-for-other-fonts-in-plots/69971)

<div class="topic-metadata">

**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 6\
**Last updated:** [October 18, 2021, 7:18pm UTC](https://discourse.julialang.org/t/unicode-support-for-other-fonts-in-plots/69971 "2021-10-18T19:18:20Z")

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We can use unicode symbols in plots, like: julia\> plot(rand(10),label="π → 10⁻¹ ×") However, if we change the fonts, most commonly that not this errors: julia\> plot(rand(10),label="π → 10⁻¹ ×",fontfamily="Computer …

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## [NN Activation Functions with Plotly Dash](https://discourse.julialang.org/t/nn-activation-functions-with-plotly-dash/69992)

<div class="topic-metadata">

**Author:** [@cepel](https://discourse.julialang.org/u/cepel)\
**Replies:** 0\
**Last updated:** [October 18, 2021, 5:44pm UTC](https://discourse.julialang.org/t/nn-activation-functions-with-plotly-dash/69992 "2021-10-18T17:44:35Z")

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Hey everyone! I developed a Dash Julia application for visualizing activation functions in neural networks. You can select multiple activation functions and compare on a line chart. Feel free to review the codes on GitH…

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## [Starting point of a nonlinear optimization using Ipopt](https://discourse.julialang.org/t/starting-point-of-a-nonlinear-optimization-using-ipopt/69959)

<div class="topic-metadata">

**Author:** [@FH96](https://discourse.julialang.org/u/FH96)\
**Replies:** 3\
**Last updated:** [October 18, 2021, 11:45am UTC](https://discourse.julialang.org/t/starting-point-of-a-nonlinear-optimization-using-ipopt/69959 "2021-10-18T11:45:27Z")

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If I don’t specify the staring point in a nonlinear optimization using Ipopt ,what does the solver starts with?

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## [Purpose of secure\_cookie in Electron.jl](https://discourse.julialang.org/t/purpose-of-secure-cookie-in-electron-jl/68296)

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**Author:** [@ettersi](https://discourse.julialang.org/u/ettersi)\
**Replies:** 3\
**Last updated:** [September 17, 2021, 8:25am UTC](https://discourse.julialang.org/t/purpose-of-secure-cookie-in-electron-jl/68296 "2021-09-17T08:25:00Z")

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When Electron.jl launches a new electron process, it passes a secure cookie which is then used to authenticate the electron process when it tries to connect back to the Julia process. I’m not sure I understand the purpos…

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## [Plots: Using multiple colours in title](https://discourse.julialang.org/t/plots-using-multiple-colours-in-title/69870)

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**Author:** [@MattSainsbury-Dale](https://discourse.julialang.org/u/MattSainsbury-Dale)\
**Replies:** 9\
**Last updated:** [October 18, 2021, 7:39am UTC](https://discourse.julialang.org/t/plots-using-multiple-colours-in-title/69870 "2021-10-18T07:39:36Z")

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Using Plots.jl, is it possible to use multiple colours in the title? Here is an example of the sort of thing I am trying to do. Thanks very much in advance.

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