# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=189

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**Page:** 190

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## [New Theoretical Analysis for ADVI / BBVI](https://discourse.julialang.org/t/new-theoretical-analysis-for-advi-bbvi/99527)

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**Author:** [@Red-Portal](https://discourse.julialang.org/u/Red-Portal)\
**Replies:** 10\
**Last updated:** [May 31, 2023, 1:37am UTC](https://discourse.julialang.org/t/new-theoretical-analysis-for-advi-bbvi/99527 "2023-05-31T01:37:38Z")

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Hi all, We’ve recently uploaded to ArXiv a theoretical analysis for ADVI (although the title says black-box VI), which I believe is the first formal full convergence proof for any black-box VI-type algorithm that uses S…

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## [Recommended way to do callbacks in MIP root node](https://discourse.julialang.org/t/recommended-way-to-do-callbacks-in-mip-root-node/99617)

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**Author:** [@felipecordera](https://discourse.julialang.org/u/felipecordera)\
**Replies:** 3\
**Last updated:** [May 31, 2023, 1:36am UTC](https://discourse.julialang.org/t/recommended-way-to-do-callbacks-in-mip-root-node/99617 "2023-05-31T01:36:26Z")

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Hi everyone, I would like to know whether there are any recommendations in the workflow for the following situation: I have defined a MIP model along with a solver-independent lazy callback function, and I would like t…

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## [CVODE\_BDF using order of magnitude fewer function evals than Julia solvers](https://discourse.julialang.org/t/cvode-bdf-using-order-of-magnitude-fewer-function-evals-than-julia-solvers/98562)

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**Author:** [@p\_f](https://discourse.julialang.org/u/p_f)\
**Replies:** 10\
**Last updated:** [May 31, 2023, 1:29am UTC](https://discourse.julialang.org/t/cvode-bdf-using-order-of-magnitude-fewer-function-evals-than-julia-solvers/98562 "2023-05-31T01:29:09Z")

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Recently ported a Matlab implementation over to Julia. My RHS function evaluates faster in Julia, which is good, but the vast majority of Julia solvers seem to require far more function evaluations. CVODE\_BDF outperforms…

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## [BiLevel with Lower Quadratic Constraints](https://discourse.julialang.org/t/bilevel-with-lower-quadratic-constraints/99603)

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**Author:** [@JeffreySarnoff](https://discourse.julialang.org/u/JeffreySarnoff)\
**Replies:** 3\
**Last updated:** [May 30, 2023, 10:26pm UTC](https://discourse.julialang.org/t/bilevel-with-lower-quadratic-constraints/99603 "2023-05-30T22:26:54Z")

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As “BilevelJuMP is not able to solve problems with quadratic constraints in the lower level.” Is there a recommended way to solve bilevel optimizations where the lower level has quadratic constraints and the upper level …

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## [ODE solving](https://discourse.julialang.org/t/ode-solving/99520)

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**Author:** [@Ordens\_Ritter](https://discourse.julialang.org/u/Ordens_Ritter)\
**Replies:** 7\
**Last updated:** [May 30, 2023, 8:48pm UTC](https://discourse.julialang.org/t/ode-solving/99520 "2023-05-30T20:48:03Z")

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I am Trying to model some temperature curves with a physically informed NN (PINN). I started solve the FOPDT first, to be able to apply it later. function FOPDT(z) τ, Κ, θ = z return \[T1\[i\] .- (1 ./ τ) .\* (-T1…

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## [How to visualize a 3D slice of a higher-dimensional space](https://discourse.julialang.org/t/how-to-visualize-a-3d-slice-of-a-higher-dimensional-space/99610)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 1\
**Last updated:** [May 30, 2023, 6:26pm UTC](https://discourse.julialang.org/t/how-to-visualize-a-3d-slice-of-a-higher-dimensional-space/99610 "2023-05-30T18:26:27Z")

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A few months ago, I read a book called The Elegant Universe and in it the author discusses Calabi-Yau manifolds and includes a plot that is a 2D slice of a Calabi-Yau manifold. Does anyone know how to go about taking a 2…

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## [BoundaError with NLopt in JuMP with a user-defined function and its gradient](https://discourse.julialang.org/t/boundaerror-with-nlopt-in-jump-with-a-user-defined-function-and-its-gradient/99598)

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**Author:** [@naouess](https://discourse.julialang.org/u/naouess)\
**Replies:** 1\
**Last updated:** [May 30, 2023, 7:28pm UTC](https://discourse.julialang.org/t/boundaerror-with-nlopt-in-jump-with-a-user-defined-function-and-its-gradient/99598 "2023-05-30T19:28:19Z")

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Hello, I am solving an NLP in JuMP with several nonlinear user-defined functions as constraints. I provide the functions and their gradients in the following way: for j in 1:24 register(m, Symbol("myfunc\_$j"), length(…

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## [Fast plotting of area-filled signals with interactive zoom](https://discourse.julialang.org/t/fast-plotting-of-area-filled-signals-with-interactive-zoom/63611)

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**Author:** [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Replies:** 8\
**Last updated:** [May 30, 2023, 7:03pm UTC](https://discourse.julialang.org/t/fast-plotting-of-area-filled-signals-with-interactive-zoom/63611 "2023-05-30T19:03:47Z")

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Plotting 50 signals below with filled areas using PyPlot.jl takes ~0.2 s (after first plot) and allows fast interactive zoom-in: Interactive zoom-in: A MWE is provided herein: using PyCall pygui(:qt5) using PyPlo…

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## [Fixed Frequency Control in DiffEq](https://discourse.julialang.org/t/fixed-frequency-control-in-diffeq/99446)

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**Author:** [@Guido\_Ballabio](https://discourse.julialang.org/u/Guido_Ballabio)\
**Replies:** 6\
**Last updated:** [May 30, 2023, 4:35pm UTC](https://discourse.julialang.org/t/fixed-frequency-control-in-diffeq/99446 "2023-05-30T16:35:48Z")

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I am trying to use DiffEq and SciML sensitivity to build NN fixed-frequency controller for physical systems. I’ve tried PeriodicCallback and ti works (see original issue)but not with Neural Networks (Lux), because only…

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## [Sobolov training in Flux - first derivative of input wrt output in loss function](https://discourse.julialang.org/t/sobolov-training-in-flux-first-derivative-of-input-wrt-output-in-loss-function/99612)

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**Author:** [@Santa1806](https://discourse.julialang.org/u/Santa1806)\
**Replies:** 0\
**Last updated:** [May 30, 2023, 3:19pm UTC](https://discourse.julialang.org/t/sobolov-training-in-flux-first-derivative-of-input-wrt-output-in-loss-function/99612 "2023-05-30T15:19:28Z")

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I have a dataset with input images x\_train, an objective value corresponding to each image y\_train, and the set of derivatives of y\_train wrt x\_train, dc\_train. I would like to train a CNN using this data, where I find t…

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## [How to plot a 3D grid in Makie](https://discourse.julialang.org/t/how-to-plot-a-3d-grid-in-makie/99575)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 3\
**Last updated:** [May 30, 2023, 3:07pm UTC](https://discourse.julialang.org/t/how-to-plot-a-3d-grid-in-makie/99575 "2023-05-30T15:07:01Z")

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It’s super easy to visualize a 3D grid with scatter!: using Makie using WGLMakie r = -2:2 fig = Figure() ax = LScene(fig\[1, 1\], show\_axis=false) scatter!(ax, \[Point3f(x,y,z) for x in r for y in r for z in r\]) fig ……

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## [What is the meaning of multiple objective functions?](https://discourse.julialang.org/t/what-is-the-meaning-of-multiple-objective-functions/51857)

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**Author:** [@prit](https://discourse.julialang.org/u/prit)\
**Replies:** 4\
**Last updated:** [May 30, 2023, 2:24pm UTC](https://discourse.julialang.org/t/what-is-the-meaning-of-multiple-objective-functions/51857 "2023-05-30T14:24:15Z")

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I have multiple objective functions in my code, created by a loop around the @objective macro. Here’s the code: using JuMP using MosekTools K = 3 N = 2 penalties = \[1.0, 3.9, 8.7\] function fac1(r::Number, i::Number, l::…

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## [Multi-physics simulation](https://discourse.julialang.org/t/multi-physics-simulation/88651)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 18\
**Last updated:** [May 30, 2023, 7:40am UTC](https://discourse.julialang.org/t/multi-physics-simulation/88651 "2023-05-30T07:40:10Z")

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As far as I know, for multi-physics simulations often software packages like Ansys or COMSOL are used. Can Julia also be used for this kind of simulations? Or can Julia be used together with these commercial SW packages…

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## [What strategy to allocate resources while respecting many constraints](https://discourse.julialang.org/t/what-strategy-to-allocate-resources-while-respecting-many-constraints/99484)

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**Author:** [@rocco\_sprmnt21](https://discourse.julialang.org/u/rocco_sprmnt21)\
**Replies:** 16\
**Last updated:** [May 29, 2023, 10:22pm UTC](https://discourse.julialang.org/t/what-strategy-to-allocate-resources-while-respecting-many-constraints/99484 "2023-05-29T22:22:46Z")

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Suppose we have a table with 8 rows and 30 (or 31) columns. We have to label each cell with G and N, respecting the following rules (sometimes some other constraint is added :slight\_smile: ) Each column (i.e. each day…

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## [3D surface plot with GR backend error from certain camera angles](https://discourse.julialang.org/t/3d-surface-plot-with-gr-backend-error-from-certain-camera-angles/99564)

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**Author:** [@bast](https://discourse.julialang.org/u/bast)\
**Replies:** 1\
**Last updated:** [May 29, 2023, 4:51pm UTC](https://discourse.julialang.org/t/3d-surface-plot-with-gr-backend-error-from-certain-camera-angles/99564 "2023-05-29T16:51:35Z")

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Hi, I am trying to do a surface plot on data with missing/NaN values but the camera angle that I want gives me the error: “GKS: Colour index is invalid in routine SET\_FILL\_COLOR\_INDEX” and the coloring is all black. Us…

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## [SciML Optimization - algorithms and convergence speed](https://discourse.julialang.org/t/sciml-optimization-algorithms-and-convergence-speed/99170)

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**Author:** [@sob](https://discourse.julialang.org/u/sob)\
**Replies:** 10\
**Last updated:** [May 29, 2023, 9:20pm UTC](https://discourse.julialang.org/t/sciml-optimization-algorithms-and-convergence-speed/99170 "2023-05-29T21:20:44Z")

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I’m currently working on a minimization problem where the loss function is of dimensions n by p, with both n and p ~100 (but not necessarily equal, although in some cases they may be). I started with a naive implementati…

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## [2D diffusion and crank nicolson](https://discourse.julialang.org/t/2d-diffusion-and-crank-nicolson/99528)

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**Author:** [@jtgreen](https://discourse.julialang.org/u/jtgreen)\
**Replies:** 0\
**Last updated:** [May 28, 2023, 7:57pm UTC](https://discourse.julialang.org/t/2d-diffusion-and-crank-nicolson/99528 "2023-05-28T19:57:02Z")

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I’m trying to solve 2D diffusion using the crank nicolson method and seem to be screwing it up. For one, Ax=b should be solved with A\\b, but gives nonsensical results. Oddly, b\\A seems to give something approximating wha…

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## [Lots of lines! in Makie](https://discourse.julialang.org/t/lots-of-lines-in-makie/99553)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 3\
**Last updated:** [May 29, 2023, 2:51pm UTC](https://discourse.julialang.org/t/lots-of-lines-in-makie/99553 "2023-05-29T14:51:32Z")

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I am making a plot of a dataset using semi-transparent lines connecting a bunch of measurements. MWE: using CairoMakie, Colors CairoMakie.activate!(type = "svg") a = √.abs.(randn(500)) b = a .\* 0.5 .+ randn() / 10 c = …

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## [How to extract priors from a Turing model](https://discourse.julialang.org/t/how-to-extract-priors-from-a-turing-model/99568)

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**Author:** [@DominiqueMakowski](https://discourse.julialang.org/u/DominiqueMakowski)\
**Replies:** 0\
**Last updated:** [May 29, 2023, 2:29pm UTC](https://discourse.julialang.org/t/how-to-extract-priors-from-a-turing-model/99568 "2023-05-29T14:29:26Z")

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Assuming the following model: # Bayesian linear regression. @model function linear\_regression(x, y) # Set variance prior. σ² ~ truncated(Normal(0, 100); lower=0) # Set intercept prior. intercept ~ Norma…

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## [Axis-generating functions in Makie](https://discourse.julialang.org/t/axis-generating-functions-in-makie/99558)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 2\
**Last updated:** [May 29, 2023, 2:23pm UTC](https://discourse.julialang.org/t/axis-generating-functions-in-makie/99558 "2023-05-29T14:23:30Z")

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I would like to organize some commonly used plots into functions. Eg function makie\_plot\_posterior\_check(figure, label, data, predicted; scatter\_color = alphacolor(colorant"black", 0.…

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## [CSV : problem to write big dataframes](https://discourse.julialang.org/t/csv-problem-to-write-big-dataframes/17343)

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**Author:** [@Fred](https://discourse.julialang.org/u/Fred)\
**Replies:** 20\
**Last updated:** [May 29, 2023, 1:04pm UTC](https://discourse.julialang.org/t/csv-problem-to-write-big-dataframes/17343 "2023-05-29T13:04:46Z")

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Hi, I have to read and write some big dataframes (100-500Mo). For a 80 Mo DataFrame, I need 220 sec to write it. And for a 500 Mo dataframe , after one hour waiting I gave up… I use the following code : julia\> using…

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## [POST request size limit](https://discourse.julialang.org/t/post-request-size-limit/98178)

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**Author:** [@sschmidhuber](https://discourse.julialang.org/u/sschmidhuber)\
**Replies:** 1\
**Last updated:** [May 29, 2023, 12:37pm UTC](https://discourse.julialang.org/t/post-request-size-limit/98178 "2023-05-29T12:37:48Z")

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Hello, I’m building a web application using Oxygen (which is using HTTP.jl). Is there a way to limit the max request size for HTTP post requests? When I’m able to check the size in the request handler, the memory is al…

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## [Using Metatheory.jl to simplify algebra expression](https://discourse.julialang.org/t/using-metatheory-jl-to-simplify-algebra-expression/99550)

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**Author:** [@VPBML](https://discourse.julialang.org/u/VPBML)\
**Replies:** 0\
**Last updated:** [May 29, 2023, 10:25am UTC](https://discourse.julialang.org/t/using-metatheory-jl-to-simplify-algebra-expression/99550 "2023-05-29T10:25:40Z")

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Hi, I am trying to use Metatheory.jl to simplify my algebra expressions (the expressions have type Expr), but did not get the results I expected. For example, when I tried to simplify the Expr :(a+(a-b)), I got :(a+(a-b…

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## [Complex Integration](https://discourse.julialang.org/t/complex-integration/99544)

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**Author:** [@Fourier](https://discourse.julialang.org/u/Fourier)\
**Replies:** 1\
**Last updated:** [May 29, 2023, 8:05am UTC](https://discourse.julialang.org/t/complex-integration/99544 "2023-05-29T08:05:27Z")

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Is there a package that has support for complex numbers when integrating? I quite liked monte carlo integration, because the integrals I am evaluating are 3 dimensional and the error of MC is dimension independant. Also…

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## [What is the underlying logic of Adding an Environment Wrapper in ReinforcementLearning.jl?](https://discourse.julialang.org/t/what-is-the-underlying-logic-of-adding-an-environment-wrapper-in-reinforcementlearning-jl/99539)

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**Author:** [@WuSiren](https://discourse.julialang.org/u/WuSiren)\
**Replies:** 1\
**Last updated:** [May 29, 2023, 7:25am UTC](https://discourse.julialang.org/t/what-is-the-underlying-logic-of-adding-an-environment-wrapper-in-reinforcementlearning-jl/99539 "2023-05-29T07:25:44Z")

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When customizing an environment using ReinforcementLearning.jl, we need to transform the environment using some environment wrappers because a TabularQApproximator only accepts states of type Int, as the example code sho…

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## [Flux: 1D convolutions (on genomic data)](https://discourse.julialang.org/t/flux-1d-convolutions-on-genomic-data/74874)

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**Author:** [@wc4wc4wc4](https://discourse.julialang.org/u/wc4wc4wc4)\
**Replies:** 20\
**Last updated:** [May 28, 2023, 7:27pm UTC](https://discourse.julialang.org/t/flux-1d-convolutions-on-genomic-data/74874 "2023-05-28T19:27:08Z")

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I am trying to recreate this tutorial from Python. This basically deals with how to apply deep learning to genomic data. As such, the input consists of sequences, where each sequence is based on a combination of any of …

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## [Mutable objects in Enzyme.jl](https://discourse.julialang.org/t/mutable-objects-in-enzyme-jl/99433)

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**Author:** [@Iris\_Allevi](https://discourse.julialang.org/u/Iris_Allevi)\
**Replies:** 7\
**Last updated:** [May 28, 2023, 5:32pm UTC](https://discourse.julialang.org/t/mutable-objects-in-enzyme-jl/99433 "2023-05-28T17:32:51Z")

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Hi everyone I am new to automatic differentiation. I decided to use Enzyme since I need to handle mutating objects (even if I am not differentiating with respect to these objects). I try to write a minimal, self-consis…

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## [Strange gradient behavior related to function applications](https://discourse.julialang.org/t/strange-gradient-behavior-related-to-function-applications/99508)

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**Author:** [@wormholestds9](https://discourse.julialang.org/u/wormholestds9)\
**Replies:** 0\
**Last updated:** [May 28, 2023, 8:36am UTC](https://discourse.julialang.org/t/strange-gradient-behavior-related-to-function-applications/99508 "2023-05-28T08:36:56Z")

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I ran into a baffling problem. I am using a sparse matrix sm as a weight matrix for a Dense unit. It is 2000x2000 sparse matrix with 100000 non-zero Float32 entries I created two Dense units: b = zeros(Float32,200…

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## [Trying to Create a Schmitt Trigger Component in ModelingToolkit.jl](https://discourse.julialang.org/t/trying-to-create-a-schmitt-trigger-component-in-modelingtoolkit-jl/99503)

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**Author:** [@astra\_kawa](https://discourse.julialang.org/u/astra_kawa)\
**Replies:** 3\
**Last updated:** [May 28, 2023, 4:40am UTC](https://discourse.julialang.org/t/trying-to-create-a-schmitt-trigger-component-in-modelingtoolkit-jl/99503 "2023-05-28T04:40:22Z")

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Hello all. I am trying to create a Schmitt trigger component in ModelingToolkit.jl. Specifically the circuit in the image below (source): I am using the IdealOpAmp component from the MTK standard library, I am assumi…

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## [Saving a DataFrame containing vectors](https://discourse.julialang.org/t/saving-a-dataframe-containing-vectors/99477)

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**Author:** [@krish-rmsh](https://discourse.julialang.org/u/krish-rmsh)\
**Replies:** 4\
**Last updated:** [May 27, 2023, 3:50pm UTC](https://discourse.julialang.org/t/saving-a-dataframe-containing-vectors/99477 "2023-05-27T15:50:06Z")

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I am trying to save a DataFrame, where one of the columns (Say “e\_list”) contains vectors of size 40. I tried the following packages, and none of them seem to work. CSV When opening the .csv file stored using the CSV…

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