# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=308

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**Page:** 309

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## [Makie (and Julia) do not automatically typecast obvious numerical representations](https://discourse.julialang.org/t/makie-and-julia-do-not-automatically-typecast-obvious-numerical-representations/75148)

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**Author:** [@filchristou](https://discourse.julialang.org/u/filchristou)\
**Replies:** 6\
**Last updated:** [January 25, 2022, 11:46am UTC](https://discourse.julialang.org/t/makie-and-julia-do-not-automatically-typecast-obvious-numerical-representations/75148 "2022-01-25T11:46:16Z")

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I have experienced that Julia is not very generous with automatic typecasting (or type conversion). e.g. f(x::Int) = x f(1.0) ERROR: MethodError: no method matching f(::Float64) Closest candidates are: f(::Int64) at …

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## [Missing line from deffeqflux blog post](https://discourse.julialang.org/t/missing-line-from-deffeqflux-blog-post/75141)

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**Author:** [@pl-ai](https://discourse.julialang.org/u/pl-ai)\
**Replies:** 1\
**Last updated:** [January 25, 2022, 8:10am UTC](https://discourse.julialang.org/t/missing-line-from-deffeqflux-blog-post/75141 "2022-01-25T08:10:13Z")

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In the blog post linked from the diffeqflux package (DiffEqFlux.jl – A Julia Library for Neural Differential Equations), there is this section down the page: Notice that we are not learning a solution to the ODE. Instea…

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## [Sinc Interpolation based on FFT](https://discourse.julialang.org/t/sinc-interpolation-based-on-fft/52512)

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**Author:** [@roflmaostc](https://discourse.julialang.org/u/roflmaostc)\
**Replies:** 92\
**Last updated:** [January 24, 2022, 10:18pm UTC](https://discourse.julialang.org/t/sinc-interpolation-based-on-fft/52512 "2022-01-24T22:18:47Z")

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Hey, I was trying to implement a sinc interpolation based on FFTs. One way (as far as I know) is to zero pad the frequency spectrum and calculate the IFFT of the spectrum to get a sinc interpolated signal. I ended up …

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## [CUDA aware MPI works on system but not for Julia](https://discourse.julialang.org/t/cuda-aware-mpi-works-on-system-but-not-for-julia/75060)

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**Author:** [@Chiil](https://discourse.julialang.org/u/Chiil)\
**Replies:** 30\
**Last updated:** [January 24, 2022, 10:15pm UTC](https://discourse.julialang.org/t/cuda-aware-mpi-works-on-system-but-not-for-julia/75060 "2022-01-24T22:15:10Z")

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I have problems getting CUDA-aware MPI running in Julia. I have a C++ example that works perfectly if I run it with mpiexec -n 2 ./alltoall\_test. The equivalent Julia code run with mpiexec -n 2 julia alltoall\_test.jl fai…

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## [Training Deep Neural Network using Data Parallel?](https://discourse.julialang.org/t/training-deep-neural-network-using-data-parallel/75079)

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**Author:** [@rkube](https://discourse.julialang.org/u/rkube)\
**Replies:** 5\
**Last updated:** [January 24, 2022, 9:08pm UTC](https://discourse.julialang.org/t/training-deep-neural-network-using-data-parallel/75079 "2022-01-24T21:08:19Z")

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Hi, I need to train some simpler networks on large datasets and would like to use multiple GPUs for training. Is there a tutorial or writeup on how to do this in Julia? I know about this one in torch: Multi-GPU Examples…

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## [Creating a DataFrame column as the running mean of another column](https://discourse.julialang.org/t/creating-a-dataframe-column-as-the-running-mean-of-another-column/75058)

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**Author:** [@StatisticalMouse](https://discourse.julialang.org/u/StatisticalMouse)\
**Replies:** 5\
**Last updated:** [January 24, 2022, 7:35pm UTC](https://discourse.julialang.org/t/creating-a-dataframe-column-as-the-running-mean-of-another-column/75058 "2022-01-24T19:35:42Z")

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The original code for this is a Pluto notebook, and the code in this post is supposed to be three notebook cells. The code works, and I’m pretty sure there’s a nicer syntax for the cell three, but I just can’t seem to fi…

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## [MOI.SingleVariable-in-MOI.Integer constraints are not supported by Ipopt](https://discourse.julialang.org/t/moi-singlevariable-in-moi-integer-constraints-are-not-supported-by-ipopt/75101)

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**Author:** [@oxox](https://discourse.julialang.org/u/oxox)\
**Replies:** 4\
**Last updated:** [January 24, 2022, 6:28pm UTC](https://discourse.julialang.org/t/moi-singlevariable-in-moi-integer-constraints-are-not-supported-by-ipopt/75101 "2022-01-24T18:28:21Z")

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Hi,I’m a beginner with JuMP and have some problems using the IPOPT solver. When using the IPOPT solver, there is no way to create an integer variable, an error occurs. Can someone help me？？？Thanks a lot. using JuMP u…

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## [Issue with node\_count() - type of return](https://discourse.julialang.org/t/issue-with-node-count-type-of-return/74872)

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**Author:** [@arkanver](https://discourse.julialang.org/u/arkanver)\
**Replies:** 4\
**Last updated:** [January 24, 2022, 2:09pm UTC](https://discourse.julialang.org/t/issue-with-node-count-type-of-return/74872 "2022-01-24T14:09:36Z")

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Hello all, I’ve run into an issue with JuMP function node\_count(). This function seems to check the type of value returned by the solver and expects it to be Int64, however with some solvers this isn’t the case. For exa…

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## [PGFPlotsX a matrix of RGB](https://discourse.julialang.org/t/pgfplotsx-a-matrix-of-rgb/24709)

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**Author:** [@yakir12](https://discourse.julialang.org/u/yakir12)\
**Replies:** 9\
**Last updated:** [June 7, 2019, 11:58am UTC](https://discourse.julialang.org/t/pgfplotsx-a-matrix-of-rgb/24709 "2019-06-07T11:58:44Z")

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I have an image – a matrix of RGBs. The number of pixels is relatively small (e.g. 20×20), so I want to plot it as an array of colored squares. This way the dimensions of the resulting figure won’t be dictated by the low…

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## [How to increase the maximum number of iterations in Ipopt?](https://discourse.julialang.org/t/how-to-increase-the-maximum-number-of-iterations-in-ipopt/75109)

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**Author:** [@oxox](https://discourse.julialang.org/u/oxox)\
**Replies:** 2\
**Last updated:** [January 24, 2022, 12:09pm UTC](https://discourse.julialang.org/t/how-to-increase-the-maximum-number-of-iterations-in-ipopt/75109 "2022-01-24T12:09:31Z")

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I got stuck while solving a problem with Ipopt, showing EXIT: Maximum Number of Iterations Exceeded. Its maximum number of iterations is 3000, how can I increase the maximum number of iterations？？？

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## [Zero gradients with Zygote vs correct gradients with ReverseDiff using DiffEqFlux](https://discourse.julialang.org/t/zero-gradients-with-zygote-vs-correct-gradients-with-reversediff-using-diffeqflux/74398)

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**Author:** [@JordiBolibar](https://discourse.julialang.org/u/JordiBolibar)\
**Replies:** 4\
**Last updated:** [January 24, 2022, 11:05am UTC](https://discourse.julialang.org/t/zero-gradients-with-zygote-vs-correct-gradients-with-reversediff-using-diffeqflux/74398 "2022-01-24T11:05:07Z")

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I’m having some issues (again) with Zygote trying to differentiate a UDE using DiffEqFlux. I already encountered an error with Zygote gradients with the sqrt function. For this new issue I still haven’t been able to isol…

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## [Is there any function in julia equivalent to pandas explode function](https://discourse.julialang.org/t/is-there-any-function-in-julia-equivalent-to-pandas-explode-function/75096)

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**Author:** [@Frankiewaang](https://discourse.julialang.org/u/Frankiewaang)\
**Replies:** 5\
**Last updated:** [January 24, 2022, 7:42am UTC](https://discourse.julialang.org/t/is-there-any-function-in-julia-equivalent-to-pandas-explode-function/75096 "2022-01-24T07:42:19Z")

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Hi Guys, Say I have a dataset like this: x = DataFrame(a=\[1,3,4,5\],b=\["a;b;c;d","a;c;d","a;c","b;d"\]) I want to first split the column b and then explode it to a long dataset. In python the code is like this: x\['b'\]…

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## [Vector of Flux Model Parameters Sharing Underlying Data](https://discourse.julialang.org/t/vector-of-flux-model-parameters-sharing-underlying-data/75091)

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**Author:** [@RS-Coop](https://discourse.julialang.org/u/RS-Coop)\
**Replies:** 2\
**Last updated:** [January 24, 2022, 3:12am UTC](https://discourse.julialang.org/t/vector-of-flux-model-parameters-sharing-underlying-data/75091 "2022-01-24T03:12:04Z")

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I am trying to extract the parameters of a Flux model in a single vector such that they share the same underlying data, i.e. making changes to the vector changes the model parameters. The following is based on the Flux.d…

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## [Equating ModelingToolkit parameters and variables?](https://discourse.julialang.org/t/equating-modelingtoolkit-parameters-and-variables/74642)

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**Author:** [@AndreaRH](https://discourse.julialang.org/u/AndreaRH)\
**Replies:** 4\
**Last updated:** [January 23, 2022, 6:11pm UTC](https://discourse.julialang.org/t/equating-modelingtoolkit-parameters-and-variables/74642 "2022-01-23T18:11:35Z")

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Hi! I have a first ODESystem with a parameter gNa and a second ODESystem with a variable g(t). How to create a third system that links the two together so that every time gNa appears in the first system we actually take…

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## [On the LU factorization](https://discourse.julialang.org/t/on-the-lu-factorization/75066)

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**Author:** [@scheiber\_erno](https://discourse.julialang.org/u/scheiber_erno)\
**Replies:** 1\
**Last updated:** [January 23, 2022, 1:29pm UTC](https://discourse.julialang.org/t/on-the-lu-factorization/75066 "2022-01-23T13:29:20Z")

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What is wrong with my code ? It works well six years ago. It is the case of a singular matrix. I review the following exercise: Compute the LU factorization of the matrix A=\[1 2 -1 3 2;2 4 -2 5 1;-1 -2 1 -3 -4;3 6 2 …

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## [Access cursor position in ImageView.jl](https://discourse.julialang.org/t/access-cursor-position-in-imageview-jl/75032)

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**Author:** [@PeteS](https://discourse.julialang.org/u/PeteS)\
**Replies:** 0\
**Last updated:** [January 22, 2022, 1:48pm UTC](https://discourse.julialang.org/t/access-cursor-position-in-imageview-jl/75032 "2022-01-22T13:48:53Z")

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Is it possible to access (and override) the cursor event in ImageView? I’m displaying an indexed image of a microstructure, and at any given (x, y) position I would like to display my data rather than the pixel colour.

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## [Query.jl, referencing \`\_.key\` in \`@groupby |\> @map\`](https://discourse.julialang.org/t/query-jl-referencing-key-in-groupby-map/17318)

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**Author:** [@leethargo](https://discourse.julialang.org/u/leethargo)\
**Replies:** 7\
**Last updated:** [January 22, 2022, 11:19pm UTC](https://discourse.julialang.org/t/query-jl-referencing-key-in-groupby-map/17318 "2022-01-22T23:19:14Z")

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I followed the recording of the Queryverse tutorial at JuliaCon by @davidanthoff and now get errors when I use similar queries. In particular, I want to use the \_.key shortcut in this query (see full example): data |\> …

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## [MLJ KNNRegressor BruteTree broken for predict-- load error brutetree has no field indices...?](https://discourse.julialang.org/t/mlj-knnregressor-brutetree-broken-for-predict-load-error-brutetree-has-no-field-indices/74837)

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**Author:** [@diadora77](https://discourse.julialang.org/u/diadora77)\
**Replies:** 4\
**Last updated:** [January 22, 2022, 5:02pm UTC](https://discourse.julialang.org/t/mlj-knnregressor-brutetree-broken-for-predict-load-error-brutetree-has-no-field-indices/74837 "2022-01-22T17:02:51Z")

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Using MLJ’s NearestNeighbors KNNRegressor and attempted to use BruteTree algorithm. Get the following error when attempting to use predict: ERROR: LoadError: type BruteTree has no field indices followed by usual stack t…

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## [Incorporating time lag in observation models](https://discourse.julialang.org/t/incorporating-time-lag-in-observation-models/75002)

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**Author:** [@vembha](https://discourse.julialang.org/u/vembha)\
**Replies:** 3\
**Last updated:** [January 22, 2022, 12:57pm UTC](https://discourse.julialang.org/t/incorporating-time-lag-in-observation-models/75002 "2022-01-22T12:57:47Z")

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Hello. I am estimating parameters of a simple SIR epidemic model (shown below) by fitting the model to a known time series data: Deterministic model: function SIR\_model(du, u, p, t) S, I, R = u β, γ = p du…

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## [Only explicit solvers work for stiff PDE-derived ODEs, stiff solvers crashing](https://discourse.julialang.org/t/only-explicit-solvers-work-for-stiff-pde-derived-odes-stiff-solvers-crashing/74907)

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**Author:** [@ash](https://discourse.julialang.org/u/ash)\
**Replies:** 11\
**Last updated:** [January 22, 2022, 2:05am UTC](https://discourse.julialang.org/t/only-explicit-solvers-work-for-stiff-pde-derived-odes-stiff-solvers-crashing/74907 "2022-01-22T02:05:04Z")

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I apologize for posting about this PDE many times over the past few days, but I am pursuing several different approaches and each comes with its own issues. The system is given by: \\begin{gathered} \\frac{\\partial c\_{1…

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## [How to reset slider value](https://discourse.julialang.org/t/how-to-reset-slider-value/75016)

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**Author:** [@das](https://discourse.julialang.org/u/das)\
**Replies:** 0\
**Last updated:** [January 21, 2022, 11:38pm UTC](https://discourse.julialang.org/t/how-to-reset-slider-value/75016 "2022-01-21T23:38:34Z")

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Hi everyone, I need to set, read, and reset the value of a slider (using Gtk.jl). To set the value I use: notesSlider = slider(1:200, value = 1) To read the value I use: v = value(signal(notesSlider) but I’ve had not…

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## [JLD2: triggering the actual writes to file](https://discourse.julialang.org/t/jld2-triggering-the-actual-writes-to-file/74981)

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**Author:** [@Gregstrq](https://discourse.julialang.org/u/Gregstrq)\
**Replies:** 3\
**Last updated:** [January 21, 2022, 3:34pm UTC](https://discourse.julialang.org/t/jld2-triggering-the-actual-writes-to-file/74981 "2022-01-21T15:34:28Z")

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Let’s say I saved a dataset named “dataset” to “file.jld2”: using JLD2, Random jldopen("file.jld2", "w") do fd fd\["dataset"\] = \[randn(100,100) for i=1:100\] end Now, I want to alter one of the entries in the dataset…

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## [Get Axis from Scene](https://discourse.julialang.org/t/get-axis-from-scene/74935)

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**Author:** [@fbanning](https://discourse.julialang.org/u/fbanning)\
**Replies:** 1\
**Last updated:** [January 21, 2022, 12:45pm UTC](https://discourse.julialang.org/t/get-axis-from-scene/74935 "2022-01-21T12:45:51Z")

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If I have a reference to a scene, how can I get a reference to its corresponding axis? Take the following case: fig = Figure() ax = Axis(fig\[1,1\]) s = ax.scene Now if I only have s , how can I get ax? Intuitively I’v…

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## [NEAT implementation using FLux](https://discourse.julialang.org/t/neat-implementation-using-flux/74931)

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**Author:** [@SanAlphaTau](https://discourse.julialang.org/u/SanAlphaTau)\
**Replies:** 2\
**Last updated:** [January 21, 2022, 10:00am UTC](https://discourse.julialang.org/t/neat-implementation-using-flux/74931 "2022-01-21T10:00:10Z")

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Heya, I am trying to implement a simplified version of the NEAT algorithm in julia for a project. I was just wondering what the best way of mapping my genomes into actual code it. Can I build flux models “neuron by neur…

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## [Objective bound of a model within the callback](https://discourse.julialang.org/t/objective-bound-of-a-model-within-the-callback/74941)

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**Author:** [@ahmad88](https://discourse.julialang.org/u/ahmad88)\
**Replies:** 3\
**Last updated:** [January 21, 2022, 9:22am UTC](https://discourse.julialang.org/t/objective-bound-of-a-model-within-the-callback/74941 "2022-01-21T09:22:08Z")

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I have a model where I try to add cuts to it within the callback, I am trying to access the objective bound of the model but it is not possible in the callback with the following error message Error evaluating cec-proce…

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## [Makie - Uneven dash distribution](https://discourse.julialang.org/t/makie-uneven-dash-distribution/70100)

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**Author:** [@nandoconde](https://discourse.julialang.org/u/nandoconde)\
**Replies:** 5\
**Last updated:** [January 21, 2022, 9:05am UTC](https://discourse.julialang.org/t/makie-uneven-dash-distribution/70100 "2022-01-21T09:05:55Z")

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Hello! I was experimenting with different linewidths for my paper and this happened when the :dash or the :dot linestyles were selected with a high linewidth: Is it a bug? Can it be fixed? Thanks!

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## [Monitoring GPU utilization and memory usage](https://discourse.julialang.org/t/monitoring-gpu-utilization-and-memory-usage/74958)

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**Author:** [@johnbb](https://discourse.julialang.org/u/johnbb)\
**Replies:** 2\
**Last updated:** [January 21, 2022, 8:05am UTC](https://discourse.julialang.org/t/monitoring-gpu-utilization-and-memory-usage/74958 "2022-01-21T08:05:25Z")

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While training Flux models, I would like to monitor the (Nvidia) GPU utilization and memory usage. Is there an alternative to dump output from nvidia-smi to a file and read and plot the data in Julia?

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## [Hessian with user-defined functions in MathOptNLSModel](https://discourse.julialang.org/t/hessian-with-user-defined-functions-in-mathoptnlsmodel/74672)

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**Author:** [@DanielVandH](https://discourse.julialang.org/u/DanielVandH)\
**Replies:** 2\
**Last updated:** [January 20, 2022, 10:04pm UTC](https://discourse.julialang.org/t/hessian-with-user-defined-functions-in-mathoptnlsmodel/74672 "2022-01-20T22:04:04Z")

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I am trying to use user-defined functions with the MathOptNLSModel for solving nonlinear least squares problems. I use: using JuMP using NLPModelsJuMP using JSOSolvers model = Mod…

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## [Convolutional GRU/LSTM in Flux?](https://discourse.julialang.org/t/convolutional-gru-lstm-in-flux/74770)

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**Author:** [@johnbb](https://discourse.julialang.org/u/johnbb)\
**Replies:** 4\
**Last updated:** [January 20, 2022, 8:46pm UTC](https://discourse.julialang.org/t/convolutional-gru-lstm-in-flux/74770 "2022-01-20T20:46:21Z")

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Is there any implementation of (2D) convolutional GRU, LSTM or similar based on Flux? A similar question was raised in Sept. 2020.

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## [Fitting Mixed Effects Models - Python, Julia or R?](https://discourse.julialang.org/t/fitting-mixed-effects-models-python-julia-or-r/74955)

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**Author:** [@dm13450](https://discourse.julialang.org/u/dm13450)\
**Replies:** 0\
**Last updated:** [January 20, 2022, 8:13pm UTC](https://discourse.julialang.org/t/fitting-mixed-effects-models-python-julia-or-r/74955 "2022-01-20T20:13:36Z")

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I’ve written a blog post bench-marking Julia, Python and R when fitting a mixed effects model. Julia comes out top (by quite a bit!), so if you ever need to convince someone, hopefully this will help!

[Previous page](https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=307)

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