# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=217

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**Page:** 218

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## [Recommended optimizer in OptimizationBBO](https://discourse.julialang.org/t/recommended-optimizer-in-optimizationbbo/94188)

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**Author:** [@magnumopus94](https://discourse.julialang.org/u/magnumopus94)\
**Replies:** 1\
**Last updated:** [February 7, 2023, 11:53am UTC](https://discourse.julialang.org/t/recommended-optimizer-in-optimizationbbo/94188 "2023-02-07T11:53:51Z")

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Hello! I’ve been using the OptimizationBBO.jl recently. In the GitHub page, it is stated that The recommended optimizer is BBO\_adaptive\_de\_rand\_1\_bin\_radiuslimited() May I know why this is the case? On what basis i…

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## [MTK: interpolation of observed variables?](https://discourse.julialang.org/t/mtk-interpolation-of-observed-variables/94193)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 1\
**Last updated:** [February 7, 2023, 11:01am UTC](https://discourse.julialang.org/t/mtk-interpolation-of-observed-variables/94193 "2023-02-07T11:01:55Z")

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Suppose I do a simulation of a model using ModelingToolkit.jl, where x is the state, y is an observed variable, and the solution object is sol. Then sol\[x\] sol\[y\] give vectors of the solution of x and y at the time poi…

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## [Constrain 2D array variable to contain a value \`x\` number of times](https://discourse.julialang.org/t/constrain-2d-array-variable-to-contain-a-value-x-number-of-times/94180)

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**Author:** [@dash102](https://discourse.julialang.org/u/dash102)\
**Replies:** 3\
**Last updated:** [February 7, 2023, 4:20am UTC](https://discourse.julialang.org/t/constrain-2d-array-variable-to-contain-a-value-x-number-of-times/94180 "2023-02-07T04:20:31Z")

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I am trying to solve for a 2D array x of dimension 4x2 that satisfy the following: x contains integers between 0 and 5 (inclusive) For each column col of x: 1 \<= col\[i\] - col\[i-2\] \<= 2 for i = 3, 4, 7, 8 col\[i\] % …

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## [Named objects in .obj files](https://discourse.julialang.org/t/named-objects-in-obj-files/94185)

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**Author:** [@airpmb](https://discourse.julialang.org/u/airpmb)\
**Replies:** 0\
**Last updated:** [February 7, 2023, 3:56am UTC](https://discourse.julialang.org/t/named-objects-in-obj-files/94185 "2023-02-07T03:56:26Z")

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I have .obj format files exported from Blender, which include object names (o keyword). I’d like to retain the association between these object names and the geometry they refer to. As far as I can tell this isn’t curren…

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## [Julia/Flux creating a model correctly - using Chain Embedding layer reshaping & Dense layers](https://discourse.julialang.org/t/julia-flux-creating-a-model-correctly-using-chain-embedding-layer-reshaping-dense-layers/94089)

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**Author:** [@roeya](https://discourse.julialang.org/u/roeya)\
**Replies:** 3\
**Last updated:** [February 7, 2023, 1:05am UTC](https://discourse.julialang.org/t/julia-flux-creating-a-model-correctly-using-chain-embedding-layer-reshaping-dense-layers/94089 "2023-02-07T01:05:52Z")

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I am trying to follow an old article about word embedding in Julia language with Flux: Julia Word Embedding Layer in Flux - Self Trained - Getting to Know Julia As it is an old outdated article I managed to handle the e…

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## [How to access variables and expressions faster in jump](https://discourse.julialang.org/t/how-to-access-variables-and-expressions-faster-in-jump/94123)

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**Author:** [@Betristor](https://discourse.julialang.org/u/Betristor)\
**Replies:** 4\
**Last updated:** [February 6, 2023, 7:42pm UTC](https://discourse.julialang.org/t/how-to-access-variables-and-expressions-faster-in-jump/94123 "2023-02-06T19:42:58Z")

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I established a very large model using julia with plenty of variables and expressions. Though not all of these will be meaningful for accessing, I still wrote all into results in dataframe and then saved to csv files. I’…

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## [Case study: Speeding up a logistic regression with RHS prior (Turing vs Numpyro) - any tricks I'm missing?](https://discourse.julialang.org/t/case-study-speeding-up-a-logistic-regression-with-rhs-prior-turing-vs-numpyro-any-tricks-im-missing/87681)

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**Author:** [@svilupp](https://discourse.julialang.org/u/svilupp)\
**Replies:** 38\
**Last updated:** [February 6, 2023, 7:34pm UTC](https://discourse.julialang.org/t/case-study-speeding-up-a-logistic-regression-with-rhs-prior-turing-vs-numpyro-any-tricks-im-missing/87681 "2023-02-06T19:34:06Z")

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Inspired by the recent long discussion on Slack around the performance of Turing, I’ve decided to try to beat my go-to implementation in Numpyro (and failed). I’d appreciate any tips or tricks on how to further speed up…

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## [Filtering 2D data in Julia](https://discourse.julialang.org/t/filtering-2d-data-in-julia/94122)

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**Author:** [@marianoarnaiz](https://discourse.julialang.org/u/marianoarnaiz)\
**Replies:** 5\
**Last updated:** [February 6, 2023, 7:31pm UTC](https://discourse.julialang.org/t/filtering-2d-data-in-julia/94122 "2023-02-06T19:31:49Z")

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Hi all. Is there are packaga that I can use to filter 2D data? Things like butterworth filtering, derivatives, poly fitting, spectrum computation, etc? I know a lot of this is implemente in GMT.jl by @joa-quim but the …

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## [Models with persistent memory usage](https://discourse.julialang.org/t/models-with-persistent-memory-usage/93215)

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**Author:** [@pfarndt](https://discourse.julialang.org/u/pfarndt)\
**Replies:** 3\
**Last updated:** [February 6, 2023, 5:12pm UTC](https://discourse.julialang.org/t/models-with-persistent-memory-usage/93215 "2023-02-06T17:12:16Z")

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I am using Turing a lot but now I have a model which would keep some persistent memory to be computational efficient. A minimal example would be: using Turing, Optim, ForwardDiff mutable struct Acomputer{T \<: Number} …

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## [How to display an array of UInt8 as a color image](https://discourse.julialang.org/t/how-to-display-an-array-of-uint8-as-a-color-image/93990)

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**Author:** [@Tetane](https://discourse.julialang.org/u/Tetane)\
**Replies:** 8\
**Last updated:** [February 6, 2023, 1:30pm UTC](https://discourse.julialang.org/t/how-to-display-an-array-of-uint8-as-a-color-image/93990 "2023-02-06T13:30:50Z")

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I have a color image represented by an array of UInt8 of size (58638, 22376, 3) that I want to display using imshow from the ImageView package. The RGB channels are contained in the third dimension of the array. I unders…

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## [How to make a fast first plot with CairoMakie?](https://discourse.julialang.org/t/how-to-make-a-fast-first-plot-with-cairomakie/94120)

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**Author:** [@YH\_Ko](https://discourse.julialang.org/u/YH_Ko)\
**Replies:** 2\
**Last updated:** [February 6, 2023, 7:23am UTC](https://discourse.julialang.org/t/how-to-make-a-fast-first-plot-with-cairomakie/94120 "2023-02-06T07:23:05Z")

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I’m new to Julia language. I have tried to follow data visualization with Makie. However, the time to first plot is too long. (~50sec) 50.087309 seconds (146.21 M allocations: 7.676 GiB, 3.69% gc time, 98.74% compi…

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## [GADFLY Font Change Not Saving](https://discourse.julialang.org/t/gadfly-font-change-not-saving/94044)

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**Author:** [@ChrisVL1](https://discourse.julialang.org/u/ChrisVL1)\
**Replies:** 5\
**Last updated:** [February 6, 2023, 2:25am UTC](https://discourse.julialang.org/t/gadfly-font-change-not-saving/94044 "2023-02-06T02:25:42Z")

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When changing the label font and saving as a PDF, the saved pdf does not display the changed font style. Here’s an example: xs = convert(Vector{Float64}, tsteps) layer2 = layer(x=xs1, y=Euler\_Maruyama1,Geom.line,Them…

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## [Query Gurobi attributes of JuMP model](https://discourse.julialang.org/t/query-gurobi-attributes-of-jump-model/94113)

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**Author:** [@jacob-roth](https://discourse.julialang.org/u/jacob-roth)\
**Replies:** 2\
**Last updated:** [February 6, 2023, 2:15am UTC](https://discourse.julialang.org/t/query-gurobi-attributes-of-jump-model/94113 "2023-02-06T02:15:33Z")

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I am interested in obtaining particular solution attributes (e.g., DualVio) of my Gurobi model constructed by JuMP. Can I use the Gurobi.jl C interface to query a solved JuMP model to obtain solution quality attributes? …

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## [3 Layered Neural Network for a simple curve fit not working](https://discourse.julialang.org/t/3-layered-neural-network-for-a-simple-curve-fit-not-working/94078)

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**Author:** [@RSH](https://discourse.julialang.org/u/RSH)\
**Replies:** 2\
**Last updated:** [February 6, 2023, 12:30am UTC](https://discourse.julialang.org/t/3-layered-neural-network-for-a-simple-curve-fit-not-working/94078 "2023-02-06T00:30:29Z")

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I am currently attempting to utilize a three-layered neural network to model the function cos(x). Despite extensive efforts to debug my code, I have been unable to identify and rectify the source of error. It is my belie…

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## [Zygote gradient error with \`reduce\` on GPU](https://discourse.julialang.org/t/zygote-gradient-error-with-reduce-on-gpu/94049)

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**Author:** [@ogoid](https://discourse.julialang.org/u/ogoid)\
**Replies:** 3\
**Last updated:** [February 6, 2023, 12:15am UTC](https://discourse.julialang.org/t/zygote-gradient-error-with-reduce-on-gpu/94049 "2023-02-06T00:15:03Z")

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Hello, I’m trying to use reduce (and mapreduce and its variants) in the loss function of a Flux neural network, but Zygote throws an error when it runs on the GPU (works fine on the CPU though). Are these functions unsu…

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## [How interpret constraint values for inequalities?](https://discourse.julialang.org/t/how-interpret-constraint-values-for-inequalities/93866)

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**Author:** [@hugh\_man](https://discourse.julialang.org/u/hugh_man)\
**Replies:** 3\
**Last updated:** [February 5, 2023, 11:59pm UTC](https://discourse.julialang.org/t/how-interpret-constraint-values-for-inequalities/93866 "2023-02-05T23:59:06Z")

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Hello, I’m trying to understand the values outputted when evaluating a constraint. In another thread I received this useful response on how to evaluate constraints. I’ll use a slightly modified example from there (pas…

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## [Mosek Solver Option](https://discourse.julialang.org/t/mosek-solver-option/94106)

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**Author:** [@A\_M](https://discourse.julialang.org/u/A_M)\
**Replies:** 3\
**Last updated:** [February 5, 2023, 11:57pm UTC](https://discourse.julialang.org/t/mosek-solver-option/94106 "2023-02-05T23:57:35Z")

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Solving a linear problem using Mosek, I set MSK\_DPAR\_INTPNT\_TOL\_PFEAS, which is Primal feasibility tolerance used by the interior-point optimizer for linear problems, to 1.0 by set\_optimizer\_attribute(model, "MSK\_DPAR\_I…

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## [Bayesian optimization](https://discourse.julialang.org/t/bayesian-optimization/94060)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 8\
**Last updated:** [February 5, 2023, 10:44pm UTC](https://discourse.julialang.org/t/bayesian-optimization/94060 "2023-02-05T22:44:45Z")

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Hello, I try to understand Bayesian optimization, which I want to use for the estimation of the power coefficient of a wind turbine which is a function of (at least) the wind speed and declines over the years. Can it b…

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## [Manipulate sparse arrays](https://discourse.julialang.org/t/manipulate-sparse-arrays/94082)

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**Author:** [@Tri](https://discourse.julialang.org/u/Tri)\
**Replies:** 2\
**Last updated:** [February 5, 2023, 10:02pm UTC](https://discourse.julialang.org/t/manipulate-sparse-arrays/94082 "2023-02-05T22:02:44Z")

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I am using sparse array as variables in the following: using Ipopt,JuMP model = Model(Ipopt.Optimizer) n = 4 @variable(model, X\[i=1:n, j=1:i-1\] \>=0) @variable(model, y\[1:n\]\>=0) @variable(model, z\[1:n\]) @NLconstraint…

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## [, and . in numbers inside CSV format](https://discourse.julialang.org/t/and-in-numbers-inside-csv-format/94087)

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**Author:** [@mpirke](https://discourse.julialang.org/u/mpirke)\
**Replies:** 7\
**Last updated:** [February 5, 2023, 5:30pm UTC](https://discourse.julialang.org/t/and-in-numbers-inside-csv-format/94087 "2023-02-05T17:30:48Z")

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Hey there! I have to following problem. I want to read in data ( .csv ) which has the following structure: data = """ col1;col2;col3;col4;col5 "05.02.2023";1000,01;2000,02;3000,03;12:00:00 "06.02.2023";4000,04;5000,05;…

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## [Passing custom struct into kernel function](https://discourse.julialang.org/t/passing-custom-struct-into-kernel-function/94069)

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**Author:** [@FujiwaraTakumiEH](https://discourse.julialang.org/u/FujiwaraTakumiEH)\
**Replies:** 1\
**Last updated:** [February 4, 2023, 10:43pm UTC](https://discourse.julialang.org/t/passing-custom-struct-into-kernel-function/94069 "2023-02-04T22:43:19Z")

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Hello, I’m still a little confused about Adapt.jl. I read several posts in the forum and tried it for my case, but it did not work…:joy: I have a custom struct like this: using Adapt using CUDA # T is either Float64 …

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## [Unable to add objectives in vector form using JuMP](https://discourse.julialang.org/t/unable-to-add-objectives-in-vector-form-using-jump/94041)

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**Author:** [@Gokhan\_Kof](https://discourse.julialang.org/u/Gokhan_Kof)\
**Replies:** 5\
**Last updated:** [February 4, 2023, 8:51pm UTC](https://discourse.julialang.org/t/unable-to-add-objectives-in-vector-form-using-jump/94041 "2023-02-04T20:51:11Z")

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Hi, I was trying to test multi-objective support of JuMP (MOO) pkg\> st Project MOO v0.0.1 Status \`~/Desktop/MOO.jl/Project.toml\` \[60bf3e95\] GLPK v1.1.0 \[4076af6c\] JuMP v1.7.0 \`https://github.com/jump-dev…

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## [How to calculate correlation and covariance matrix between columns of a TimeArray](https://discourse.julialang.org/t/how-to-calculate-correlation-and-covariance-matrix-between-columns-of-a-timearray/94038)

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**Author:** [@mdogan](https://discourse.julialang.org/u/mdogan)\
**Replies:** 1\
**Last updated:** [February 4, 2023, 8:16pm UTC](https://discourse.julialang.org/t/how-to-calculate-correlation-and-covariance-matrix-between-columns-of-a-timearray/94038 "2023-02-04T20:16:26Z")

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I’m new to Julia. I want to calculate the correlation and covariance matrix of the columns of a TimeArray. To reproduce my example, I copied my code below to construct a TimeArray. using DataFrames using TimeSeries da…

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## [Disabling grouping along x-axis in grouped boxplot](https://discourse.julialang.org/t/disabling-grouping-along-x-axis-in-grouped-boxplot/93997)

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**Author:** [@jewh](https://discourse.julialang.org/u/jewh)\
**Replies:** 1\
**Last updated:** [February 3, 2023, 10:59pm UTC](https://discourse.julialang.org/t/disabling-grouping-along-x-axis-in-grouped-boxplot/93997 "2023-02-03T22:59:29Z")

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Using the group keyword argument in Statsplots.boxplot adjusts the distance between individual boxes so that they cluster with their groups (see example below): using StatsPlots x = Vector{String}(undef, 40) for i = 1…

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## [How to create sliced views of \`CuArray\` correctly?](https://discourse.julialang.org/t/how-to-create-sliced-views-of-cuarray-correctly/93971)

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**Author:** [@jinfreedom](https://discourse.julialang.org/u/jinfreedom)\
**Replies:** 1\
**Last updated:** [February 3, 2023, 9:38pm UTC](https://discourse.julialang.org/t/how-to-create-sliced-views-of-cuarray-correctly/93971 "2023-02-03T21:38:45Z")

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Hi, I would like to split and reshape a CuArray to a StructArray “in place” as views. I used sliced views of the input CuArray and got a warning about slicing. Is there a correct way of doing the following? julia\> siz=(…

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## [Interpolate a 3D array](https://discourse.julialang.org/t/interpolate-a-3d-array/93885)

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**Author:** [@Dale\_James\_Black](https://discourse.julialang.org/u/Dale_James_Black)\
**Replies:** 19\
**Last updated:** [February 3, 2023, 6:58pm UTC](https://discourse.julialang.org/t/interpolate-a-3d-array/93885 "2023-02-03T18:58:04Z")

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If I have a 3D array along with a unit normal vector and point for a plane that intersects that array, how would I use Interpolations.jl to create a new 3D array that is the same size as the original array but where all …

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## [WriteVTK node numbering for 27 node Lagrange Hexahedron](https://discourse.julialang.org/t/writevtk-node-numbering-for-27-node-lagrange-hexahedron/93698)

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**Author:** [@jman87](https://discourse.julialang.org/u/jman87)\
**Replies:** 17\
**Last updated:** [February 3, 2023, 6:16pm UTC](https://discourse.julialang.org/t/writevtk-node-numbering-for-27-node-lagrange-hexahedron/93698 "2023-02-03T18:16:21Z")

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@jipolanco I’m trying to export a mesh containing 27-node Lagrange Hexahedron elements using WriteVTK, but I can’t seem to get the node ordering correct. Another ParaView user suggested I get the ordering from ParaView…

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## [Equivalent Circuit Optimization](https://discourse.julialang.org/t/equivalent-circuit-optimization/93907)

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**Author:** [@ellocco](https://discourse.julialang.org/u/ellocco)\
**Replies:** 9\
**Last updated:** [February 3, 2023, 4:30pm UTC](https://discourse.julialang.org/t/equivalent-circuit-optimization/93907 "2023-02-03T16:30:45Z")

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Hi, yesterday I worked on a script provided by Maxime to find an optimal solution for the parameters of an equivalent circuit. For this purpose there is the established python package impedance.py, but this package fai…

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## [MLJ: RootMeanSquaredLogError() returns Inf instead of actual score](https://discourse.julialang.org/t/mlj-rootmeansquaredlogerror-returns-inf-instead-of-actual-score/93995)

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**Author:** [@clouedoc](https://discourse.julialang.org/u/clouedoc)\
**Replies:** 0\
**Last updated:** [February 3, 2023, 3:25pm UTC](https://discourse.julialang.org/t/mlj-rootmeansquaredlogerror-returns-inf-instead-of-actual-score/93995 "2023-02-03T15:25:20Z")

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Hello, I’m trying to build a model for the Store Sales Kaggle Competition. I’ve tried to build a super-simple model that only takes two-three features and submit my predictions to Kaggle. The numbers didn’t correspond …

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## [GTK4.jl: Canvas not visible when pushed to a box](https://discourse.julialang.org/t/gtk4-jl-canvas-not-visible-when-pushed-to-a-box/93959)

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**Author:** [@sarath-menon](https://discourse.julialang.org/u/sarath-menon)\
**Replies:** 1\
**Last updated:** [February 3, 2023, 11:32am UTC](https://discourse.julialang.org/t/gtk4-jl-canvas-not-visible-when-pushed-to-a-box/93959 "2023-02-03T11:32:02Z")

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Hello. I am trying to display a canvas GTK4.jl. The documentation example works. But when I push the canvas to a GTKBox and push the box to the window (instead of pushing the canvas directly to the window), the canvas …

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