# Specific Domains **URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=194 [Latest](https://discourse.julialang.org/latest.md) · [Categories](https://discourse.julialang.org/categories.md) · [Tags](https://discourse.julialang.org/tags.md) **Page:** 195 --- ## [Usage of Measurements.jl](https://discourse.julialang.org/t/usage-of-measurements-jl/98726)

**Author:** [@Fourier](https://discourse.julialang.org/u/Fourier)\ **Replies:** 3\ **Last updated:** [May 12, 2023, 9:36am UTC](https://discourse.julialang.org/t/usage-of-measurements-jl/98726 "2023-05-12T09:36:19Z")

I want to use measurements.jl for my data analysis, because it can propagate uncertainites. However for example this input: julia\> 1 ± 1 \* 1 ± 0.5 1.0 ± 1.0 ± 0.5 ± 0.0 gives me an answer I did not expect, I thought t… --- ## [How to specify weights (wts) in MixedModels.jl?](https://discourse.julialang.org/t/how-to-specify-weights-wts-in-mixedmodels-jl/98707)

**Author:** [@Rscho314](https://discourse.julialang.org/u/Rscho314)\ **Replies:** 0\ **Last updated:** [May 11, 2023, 11:22pm UTC](https://discourse.julialang.org/t/how-to-specify-weights-wts-in-mixedmodels-jl/98707 "2023-05-11T23:22:44Z")

Hi, I specified a multilevel longitudinal model in MixedModels.jl. I am having a heteroscedasticity issue, for which I’d like to try to weight observations. So, the unweighted model: fit(MixedModel,@formula(maxtrop~1+… --- ## [Needing to plot streaming vehicle trajectories on a map similar to city or road map](https://discourse.julialang.org/t/needing-to-plot-streaming-vehicle-trajectories-on-a-map-similar-to-city-or-road-map/98705)

**Author:** [@benibilme](https://discourse.julialang.org/u/benibilme)\ **Replies:** 1\ **Last updated:** [May 12, 2023, 7:19am UTC](https://discourse.julialang.org/t/needing-to-plot-streaming-vehicle-trajectories-on-a-map-similar-to-city-or-road-map/98705 "2023-05-12T07:19:47Z")

Hello, I desparately need a plotting library, platform to plot streaming vehicle trajectories on a city map. I am trying to put distance to python ecosystem and try to stay in julia ecosystem as much as possible but I h… --- ## [Working with Multiple Vectors of Parameters](https://discourse.julialang.org/t/working-with-multiple-vectors-of-parameters/98685)

**Author:** [@astrobc1](https://discourse.julialang.org/u/astrobc1)\ **Replies:** 2\ **Last updated:** [May 11, 2023, 8:37pm UTC](https://discourse.julialang.org/t/working-with-multiple-vectors-of-parameters/98685 "2023-05-11T20:37:33Z")

I’m working with the SciML Optimization framework trying to optimize several Vectors of parameters with ReverseDiff.jl. I understand the Vector that’s passed to my objective function is flattened, so I’m also passing the… --- ## [Flux Dense Layer Type Instability](https://discourse.julialang.org/t/flux-dense-layer-type-instability/98642)

**Author:** [@Ian\_L](https://discourse.julialang.org/u/Ian_L)\ **Replies:** 7\ **Last updated:** [May 11, 2023, 4:20pm UTC](https://discourse.julialang.org/t/flux-dense-layer-type-instability/98642 "2023-05-11T16:20:12Z")

Hi. I am stumped as to why the forward pass is type unstable. It’s effectively a varying length chain similar to Flux.Chain on an alternating sequence of dense and dropout layers: struct MLP dense::Vector{Flux.Dense… --- ## [DataFrames: convert column data type](https://discourse.julialang.org/t/dataframes-convert-column-data-type/35522)

**Author:** [@Usor](https://discourse.julialang.org/u/Usor)\ **Replies:** 65\ **Last updated:** [May 11, 2023, 1:37pm UTC](https://discourse.julialang.org/t/dataframes-convert-column-data-type/35522 "2023-05-11T13:37:19Z")

Was looking around, but didn’t find an answer. Specifically, I have a DataFrame and one column has data type Int64; it has the unique values 0 and 1 (meaning obviously false and true). What is the easiest quickest way t… --- ## [Variable rate jump stops matching birth-death theory](https://discourse.julialang.org/t/variable-rate-jump-stops-matching-birth-death-theory/98609)

**Author:** [@freddie090](https://discourse.julialang.org/u/freddie090)\ **Replies:** 2\ **Last updated:** [May 11, 2023, 11:06am UTC](https://discourse.julialang.org/t/variable-rate-jump-stops-matching-birth-death-theory/98609 "2023-05-11T11:06:37Z")

I saw that a mixed birth-death ODE-jump process I was using wasn’t behaving as expected. Following some investigation, it appears that when I switch the rates from being ‘ConstantRateJump’ to ‘VariableRateJump’ the birt… --- ## [Bayesian Neural Network example in Turing](https://discourse.julialang.org/t/bayesian-neural-network-example-in-turing/98667)

**Author:** [@Patrik\_Waldmann](https://discourse.julialang.org/u/Patrik_Waldmann)\ **Replies:** 0\ **Last updated:** [May 11, 2023, 8:55am UTC](https://discourse.julialang.org/t/bayesian-neural-network-example-in-turing/98667 "2023-05-11T08:55:47Z")

I have run the Bayesian Neural Networks example in the Turing Tutorials and it works fine except for that the network weights (parameters variable) run into identifiability/convergence issues, i.e. most of them wanders a… --- ## [Is it possible to solve problem for subset of parameters?](https://discourse.julialang.org/t/is-it-possible-to-solve-problem-for-subset-of-parameters/98645)

**Author:** [@Optimization](https://discourse.julialang.org/u/Optimization)\ **Replies:** 3\ **Last updated:** [May 11, 2023, 8:53am UTC](https://discourse.julialang.org/t/is-it-possible-to-solve-problem-for-subset-of-parameters/98645 "2023-05-11T08:53:26Z")

I have a dataset which is big and I already have written the model whith the following format: @constraint(model, f in F\], sum(x\[(i,j,k)\] for (i,j,k) in families\[f\] if i == pref\[f\]) == 1) # families\[f\] is a diction… --- ## [Quiver colors in Plots.jl](https://discourse.julialang.org/t/quiver-colors-in-plots-jl/34981)

**Author:** [@alvrg](https://discourse.julialang.org/u/alvrg)\ **Replies:** 3\ **Last updated:** [May 11, 2023, 7:04am UTC](https://discourse.julialang.org/t/quiver-colors-in-plots-jl/34981 "2023-05-11T07:04:18Z")

Hi all, I made this simple example where I plot a bunch of arrows using Plots # Arrow position. x = collect(0:10) y = fill(0., 10) # Arrow direction. u = fill(1., 10) v = fill(1., 10) # Arrow color. c = collect(1:10) … --- ## [\`dualize()\` cannot take \`ignore\_objective\` argument](https://discourse.julialang.org/t/dualize-cannot-take-ignore-objective-argument/98650)

**Author:** [@g001234](https://discourse.julialang.org/u/g001234)\ **Replies:** 5\ **Last updated:** [May 10, 2023, 11:35pm UTC](https://discourse.julialang.org/t/dualize-cannot-take-ignore-objective-argument/98650 "2023-05-10T23:35:23Z")

When using Dualization.jl to dualize an LP, I used the ignore\_objective argument to turn off the objective. However, I received the following error: ERROR: MethodError: no method matching dualize(::Model, ::Nothing; dua… --- ## [ERROR: The provided \`optimizer\_constructor\` is invalid](https://discourse.julialang.org/t/error-the-provided-optimizer-constructor-is-invalid/98607)

**Author:** [@Gianmarco\_Montillo](https://discourse.julialang.org/u/Gianmarco_Montillo)\ **Replies:** 1\ **Last updated:** [May 10, 2023, 11:12pm UTC](https://discourse.julialang.org/t/error-the-provided-optimizer-constructor-is-invalid/98607 "2023-05-10T23:12:13Z")

Hello everyone, I am trying to solve a math model using Alpine.jl. Given n arrays of different dimension, n constraint of strict equalities (one for each sum of the whole array i.e. sum(x)==X, sum(y)==Y, sum(z)==Z), one … --- ## [AoG Attributes and/or Post-Plot Environment Stacking?](https://discourse.julialang.org/t/aog-attributes-and-or-post-plot-environment-stacking/98640)

**Author:** [@Nathan\_Boyer](https://discourse.julialang.org/u/Nathan_Boyer)\ **Replies:** 0\ **Last updated:** [May 10, 2023, 8:20pm UTC](https://discourse.julialang.org/t/aog-attributes-and-or-post-plot-environment-stacking/98640 "2023-05-10T20:20:18Z")

I have an AlgebraOfGraphics.Layers object drawn in my package environment which has CairoMakie as a dependency. I now find myself needing to zoom in. I assume there is an axis option I can use to set xlimits and ylimits… --- ## [Concatenating DataFrames in parallel](https://discourse.julialang.org/t/concatenating-dataframes-in-parallel/98630)

**Author:** [@gaspardelanuit](https://discourse.julialang.org/u/gaspardelanuit)\ **Replies:** 4\ **Last updated:** [May 10, 2023, 5:42pm UTC](https://discourse.julialang.org/t/concatenating-dataframes-in-parallel/98630 "2023-05-10T17:42:16Z")

I am trying to run multiple simulations in parallel. The output of these simulations is a DataFrame. My goal is to return a concatenated DataFrame with all of the simulations. The simple code would be using DataFrames… --- ## [Neural network training for DSGE model](https://discourse.julialang.org/t/neural-network-training-for-dsge-model/98567)

**Author:** [@Vahagn](https://discourse.julialang.org/u/Vahagn)\ **Replies:** 0\ **Last updated:** [May 9, 2023, 5:55pm UTC](https://discourse.julialang.org/t/neural-network-training-for-dsge-model/98567 "2023-05-09T17:55:11Z")

Hi, I have a DSGE model for which I need to approximate decision functions using neural network. I have already written many parts of my code. But I don’t know how to train it. I have written some training loop in the b… --- ## [Discrete systems in MTK](https://discourse.julialang.org/t/discrete-systems-in-mtk/98602)

**Author:** [@HamzaKh99](https://discourse.julialang.org/u/HamzaKh99)\ **Replies:** 1\ **Last updated:** [May 10, 2023, 12:00pm UTC](https://discourse.julialang.org/t/discrete-systems-in-mtk/98602 "2023-05-10T12:00:08Z")

Hello everyone! I’m trying to do a discrete system example, using Difference and Differential functions, when I create the ODEProblem without structural\_simplify() I get the results I want. \`using ModelingToolkit usin… --- ## [How to optimize multiple ODEs at once?](https://discourse.julialang.org/t/how-to-optimize-multiple-odes-at-once/98194)

**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\ **Replies:** 2\ **Last updated:** [May 10, 2023, 8:39am UTC](https://discourse.julialang.org/t/how-to-optimize-multiple-odes-at-once/98194 "2023-05-10T08:39:05Z")

Hello, I have a set of several ODEs to describe the interaction between six bacteria and six phages (one for bacterium). Collectively, I have 18 equations with 7 parameters. What is the approach to finding the values o… --- ## [GPs: sum of independent Kernels](https://discourse.julialang.org/t/gps-sum-of-independent-kernels/98542)

**Author:** [@martincornejo](https://discourse.julialang.org/u/martincornejo)\ **Replies:** 2\ **Last updated:** [May 10, 2023, 8:00am UTC](https://discourse.julialang.org/t/gps-sum-of-independent-kernels/98542 "2023-05-10T08:00:58Z")

The documentation of KernelFunctions.jl specifies many building blocks to define composite Kernels. But I can’t find a way to build a sum of independent Kernels, something similar to the KernelTensorProduct but with addi… --- ## [Zygote Update with Parametric Type](https://discourse.julialang.org/t/zygote-update-with-parametric-type/98588)

**Author:** [@Ian\_L](https://discourse.julialang.org/u/Ian_L)\ **Replies:** 5\ **Last updated:** [May 10, 2023, 6:26am UTC](https://discourse.julialang.org/t/zygote-update-with-parametric-type/98588 "2023-05-10T06:26:22Z")

Hi. I’m trying to update my flux model which is parameterized by two types: abstract type C end struct A \<: C end struct B \<: C end struct Block{T\<:C} C\_inout::Int time::Vector{Float64} end Flux.@functor Block… --- ## [Callbacks - Accessing Gurobi specific functionality](https://discourse.julialang.org/t/callbacks-accessing-gurobi-specific-functionality/98560)

**Author:** [@Sokar](https://discourse.julialang.org/u/Sokar)\ **Replies:** 2\ **Last updated:** [May 10, 2023, 5:20am UTC](https://discourse.julialang.org/t/callbacks-accessing-gurobi-specific-functionality/98560 "2023-05-10T05:20:21Z")

Hi everyone. Working on my master thesis project, I have run into some problems using JuMP and Gurobi. I need to use Gurobi specific callback functionality, but as far as I can tell, this requires me to construct my mod… --- ## [Loss/Accuracy computation in validation set in Flux](https://discourse.julialang.org/t/loss-accuracy-computation-in-validation-set-in-flux/98590)

**Author:** [@imantha](https://discourse.julialang.org/u/imantha)\ **Replies:** 1\ **Last updated:** [May 10, 2023, 5:05am UTC](https://discourse.julialang.org/t/loss-accuracy-computation-in-validation-set-in-flux/98590 "2023-05-10T05:05:24Z")

Hi I have written the code below following the examples in Flux model zoo (conv\_mnist). I have a feeling I am doing something wrong especially in the validation set. I have some experience with pytorch and usually when y… --- ## [How to use fft to 2d vector data](https://discourse.julialang.org/t/how-to-use-fft-to-2d-vector-data/98530)

**Author:** [@xiaoming](https://discourse.julialang.org/u/xiaoming)\ **Replies:** 2\ **Last updated:** [May 10, 2023, 1:17am UTC](https://discourse.julialang.org/t/how-to-use-fft-to-2d-vector-data/98530 "2023-05-10T01:17:02Z")

I have some data like this: function f(x) \[sin(2\*pi\*x\[1\])\*cos(2\*pi\*x\[2\]), cos(2\*pi\*x\[1\])\*sin(2\*pi\*x\[2\])\] end N=200 data = \[f(\[i/N,j/N\]) for i in 0:N-1, j in 0:N-1\] which is a matrix of size N\\times N, with vector e… --- ## [Zygote adjoints for cholesky factorization on sparse arrays](https://discourse.julialang.org/t/zygote-adjoints-for-cholesky-factorization-on-sparse-arrays/98578)

**Author:** [@Ian\_L](https://discourse.julialang.org/u/Ian_L)\ **Replies:** 0\ **Last updated:** [May 9, 2023, 9:53pm UTC](https://discourse.julialang.org/t/zygote-adjoints-for-cholesky-factorization-on-sparse-arrays/98578 "2023-05-09T21:53:30Z")

Hi. Is there a quick and dirty way of getting AD to work when dealing with cholesky factorizations? The example below performs factorization (must be done inside) followed by solving a system of equations. The goal is t… --- ## [@NLconstraint and String Name](https://discourse.julialang.org/t/nlconstraint-and-string-name/98550)

**Author:** [@Mirsad\_Cosovic](https://discourse.julialang.org/u/Mirsad_Cosovic)\ **Replies:** 4\ **Last updated:** [May 9, 2023, 8:59pm UTC](https://discourse.julialang.org/t/nlconstraint-and-string-name/98550 "2023-05-09T20:59:38Z")

Can the string be included to represent the constraint name in non-linear constraints using @NLconstraint, akin to @constraint’s base\_name functionality? --- ## [Random variations between results of CPU and GPU computation](https://discourse.julialang.org/t/random-variations-between-results-of-cpu-and-gpu-computation/98517)

**Author:** [@ReWoP](https://discourse.julialang.org/u/ReWoP)\ **Replies:** 7\ **Last updated:** [May 9, 2023, 7:02pm UTC](https://discourse.julialang.org/t/random-variations-between-results-of-cpu-and-gpu-computation/98517 "2023-05-09T19:02:20Z")

Hi all, I’ve noticed that I’m getting some variations between the results computed in the GPU VS the ones obtained in the CPU. Here is a simple example: a = CUDA.rand(Float64, 10000); @show CUDA.sum(a) - sum(Array(a)… --- ## [GLMakie. How to choose a specific GPU?](https://discourse.julialang.org/t/glmakie-how-to-choose-a-specific-gpu/98557)

**Author:** [@fedoroff](https://discourse.julialang.org/u/fedoroff)\ **Replies:** 4\ **Last updated:** [May 9, 2023, 4:12pm UTC](https://discourse.julialang.org/t/glmakie-how-to-choose-a-specific-gpu/98557 "2023-05-09T16:12:46Z")

If I’m using GLMakie on a system with multiple GPUs, how can I select a specific GPU unit for rendering? --- ## [Parallelization of Genetic Algorithm (Evolutionaty.jl) with Distributed.jl and Gurobi](https://discourse.julialang.org/t/parallelization-of-genetic-algorithm-evolutionaty-jl-with-distributed-jl-and-gurobi/98389)

**Author:** [@umbe](https://discourse.julialang.org/u/umbe)\ **Replies:** 4\ **Last updated:** [May 9, 2023, 3:53pm UTC](https://discourse.julialang.org/t/parallelization-of-genetic-algorithm-evolutionaty-jl-with-distributed-jl-and-gurobi/98389 "2023-05-09T15:53:32Z")

Hello to everyone, I’m trying to solve an nested optimization problem that is structured in the following way: Master Problem: heuristic solver (genetic algorithm with Evolutionary.jl) for nonlinear black box problem S… --- ## [Can I name new JuMP constraints in a function using an argument?](https://discourse.julialang.org/t/can-i-name-new-jump-constraints-in-a-function-using-an-argument/95640)

**Author:** [@sallyrobson](https://discourse.julialang.org/u/sallyrobson)\ **Replies:** 2\ **Last updated:** [May 9, 2023, 1:30pm UTC](https://discourse.julialang.org/t/can-i-name-new-jump-constraints-in-a-function-using-an-argument/95640 "2023-05-09T13:30:09Z")

I’m trying to define a function that would add a JuMP constraint to a model, and I would like to set the name of the constraint using an argument from the function. When I have tried to do this in the past it just sets t… --- ## [Deactivate plot display to avoid need for X server](https://discourse.julialang.org/t/deactivate-plot-display-to-avoid-need-for-x-server/19359)

**Author:** [@samo](https://discourse.julialang.org/u/samo)\ **Replies:** 16\ **Last updated:** [May 9, 2023, 9:37am UTC](https://discourse.julialang.org/t/deactivate-plot-display-to-avoid-need-for-x-server/19359 "2023-05-09T09:37:54Z")

I use the following type of code to create a gif animation: using Plots anim = Animation(); for it = 1:nt contourf(...); frame(anim); end gif(anim, "test.gif", fps = 15); This works fine on my local noteboo… --- ## [JuMP: How to see output of particular variable and indicies?](https://discourse.julialang.org/t/jump-how-to-see-output-of-particular-variable-and-indicies/98505)

**Author:** [@Optimization](https://discourse.julialang.org/u/Optimization)\ **Replies:** 5\ **Last updated:** [May 9, 2023, 9:22am UTC](https://discourse.julialang.org/t/jump-how-to-see-output-of-particular-variable-and-indicies/98505 "2023-05-09T09:22:49Z")

Hi there Is it possible to ask JuMp to just show some particular indicies of varaiables? For instance let’s say we have a binary variable @variable(model, x\[i = 2:3, j = 1:2:30, \["A", "B",..."Z"\]\] \>= 0, Bin) and aft… [Previous page](https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=193) [Next page](https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=195)