# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=377

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**Page:** 378

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## [\`ForwardDiff\` and \`LAPACK\` don't get along](https://discourse.julialang.org/t/forwarddiff-and-lapack-dont-get-along/58397)

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**Author:** [@Ross\_Boylan](https://discourse.julialang.org/u/Ross_Boylan)\
**Replies:** 2\
**Last updated:** [April 2, 2021, 2:23pm UTC](https://discourse.julialang.org/t/forwarddiff-and-lapack-dont-get-along/58397 "2021-04-02T14:23:59Z")

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ForwardDiff only works with pure julia code AFAIK, which means it won’t work with the external calls to BLAS or LAPACK. When I inadvertently combine them by using qr() it doesn’t work. The question is what to do about …

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## [The "sum" in constraint](https://discourse.julialang.org/t/the-sum-in-constraint/58434)

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**Author:** [@hxxx123](https://discourse.julialang.org/u/hxxx123)\
**Replies:** 2\
**Last updated:** [April 2, 2021, 1:50pm UTC](https://discourse.julialang.org/t/the-sum-in-constraint/58434 "2021-04-02T13:50:37Z")

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I’m trying to add one constraint :sum of “t\[i,j\]x\[i,j\]\<=10". T is one "1111” metrix and x\[1:11,1:11\] are binary variables.Seems to be error.

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## [Stheno.jl@0.7](https://discourse.julialang.org/t/stheno-jl-0-7/58440)

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**Author:** [@willtebbutt](https://discourse.julialang.org/u/willtebbutt)\
**Replies:** 0\
**Last updated:** [April 2, 2021, 11:53am UTC](https://discourse.julialang.org/t/stheno-jl-0-7/58440 "2021-04-02T11:53:21Z")

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Stheno.jl v0.7 has now been released. It is a very breaking release, in that much of the main user-facing interface has been refactored to ensure compatibility with the AbstractGPs.jl ecosystem that the JuliaGaussianProc…

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## [VRP with JuMP](https://discourse.julialang.org/t/vrp-with-jump/58438)

<div class="topic-metadata">

**Author:** [@hxxx123](https://discourse.julialang.org/u/hxxx123)\
**Replies:** 1\
**Last updated:** [April 2, 2021, 11:22am UTC](https://discourse.julialang.org/t/vrp-with-jump/58438 "2021-04-02T11:22:28Z")

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One VRP without time window: n customers who has n different loads need to be met at n locations,every vehicle have same capacity,which is m. we don’t need to consider serivce times.How to get minimum number of vehicle…

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## [How to make a basic classification in flux?](https://discourse.julialang.org/t/how-to-make-a-basic-classification-in-flux/58358)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 2\
**Last updated:** [April 2, 2021, 10:17am UTC](https://discourse.julialang.org/t/how-to-make-a-basic-classification-in-flux/58358 "2021-04-02T10:17:00Z")

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I am trying to make a basic classification in Flux, but I am obtainining crazy errors. Where am I wrong ? These are my attempts: Version 1: basic of the basic using Random, Flux x = \[0.1 10; 0.13 13; 0.17 17; 0.2 20; …

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## [Flux Custom Loss Function Not Working Properly](https://discourse.julialang.org/t/flux-custom-loss-function-not-working-properly/58090)

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**Author:** [@rmcsqrd](https://discourse.julialang.org/u/rmcsqrd)\
**Replies:** 20\
**Last updated:** [April 2, 2021, 10:09am UTC](https://discourse.julialang.org/t/flux-custom-loss-function-not-working-properly/58090 "2021-04-02T10:09:21Z")

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Hello, I am trying to implement the A3C reinforcement learning algorithm in Flux.jl using a custom loss function described in the algorithm. I am having trouble with my custom loss function - the parameters of my model d…

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## [Error While adding CuArrays.jl package](https://discourse.julialang.org/t/error-while-adding-cuarrays-jl-package/58387)

<div class="topic-metadata">

**Author:** [@Sumanshekhar17](https://discourse.julialang.org/u/Sumanshekhar17)\
**Replies:** 12\
**Last updated:** [April 2, 2021, 10:02am UTC](https://discourse.julialang.org/t/error-while-adding-cuarrays-jl-package/58387 "2021-04-02T10:02:13Z")

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There are two problems that I am facing first is that- I have tried CUDA.has\_cuda(), and it gave me false. The second is that when I tried to add CuArrays.jl it gave me this error- julia\> import Pkg julia\> Pkg.add("C…

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## [Factor mixture model in Turing - too slow?](https://discourse.julialang.org/t/factor-mixture-model-in-turing-too-slow/58394)

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**Author:** [@opera\_malenky](https://discourse.julialang.org/u/opera_malenky)\
**Replies:** 1\
**Last updated:** [April 2, 2021, 12:32am UTC](https://discourse.julialang.org/t/factor-mixture-model-in-turing-too-slow/58394 "2021-04-02T00:32:51Z")

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I have been trying to make a factor mixture model in Turing, but have run into some performance issues. To see where the slowdown comes from, I started by splitting the model into two separate models: a simple factor mo…

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## [Rotate camera about point in Makie 3D scene](https://discourse.julialang.org/t/rotate-camera-about-point-in-makie-3d-scene/58337)

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**Author:** [@airpmb](https://discourse.julialang.org/u/airpmb)\
**Replies:** 4\
**Last updated:** [April 1, 2021, 8:34pm UTC](https://discourse.julialang.org/t/rotate-camera-about-point-in-makie-3d-scene/58337 "2021-04-01T20:34:02Z")

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This is what I’ve got for keeping my 3D scene pointed at the origin. It seems a bit janky, is there a better way? function lookcenter(scene, stopper) @async begin while !stopper\[\] && isopen(scene) sleep(0.25…

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## [Non-convex optimization](https://discourse.julialang.org/t/non-convex-optimization/58227)

<div class="topic-metadata">

**Author:** [@optimist](https://discourse.julialang.org/u/optimist)\
**Replies:** 2\
**Last updated:** [April 1, 2021, 11:35pm UTC](https://discourse.julialang.org/t/non-convex-optimization/58227 "2021-04-01T23:35:36Z")

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I am solving a non linear optimization using Ipopt. The problem is non-convex but Ipopt gives a good enough answer. The documentation on use of nonlinear parameters and non-linear expressions is somewhat thin. Suppose …

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## [Inverse functions using TaylorSeries.jl](https://discourse.julialang.org/t/inverse-functions-using-taylorseries-jl/43382)

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**Author:** [@dpsanders](https://discourse.julialang.org/u/dpsanders)\
**Replies:** 8\
**Last updated:** [April 1, 2021, 11:24pm UTC](https://discourse.julialang.org/t/inverse-functions-using-taylorseries-jl/43382 "2021-04-01T23:24:06Z")

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Hi @ChrisRackauckas and thread, I’m interested in using AD, and so have been something like 90% successful using TaylorSeries.jl to generate the inverse function to almost any general arbitrary function. For example T…

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## [Scientific Notation in Plots.jl colorbar](https://discourse.julialang.org/t/scientific-notation-in-plots-jl-colorbar/57793)

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**Author:** [@lsterzinger](https://discourse.julialang.org/u/lsterzinger)\
**Replies:** 8\
**Last updated:** [April 1, 2021, 9:31pm UTC](https://discourse.julialang.org/t/scientific-notation-in-plots-jl-colorbar/57793 "2021-04-01T21:31:30Z")

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Hello, edit: working example using Plots x = rand(10,10) / 1e6 contourf(x) I don’t like how the colorbar’s labels are cut off by the plot edge. Is there a way to tell the plotting package to use scientific notation …

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## [Build\_function from differential equation](https://discourse.julialang.org/t/build-function-from-differential-equation/58276)

<div class="topic-metadata">

**Author:** [@ohmsweetohm1](https://discourse.julialang.org/u/ohmsweetohm1)\
**Replies:** 2\
**Last updated:** [April 1, 2021, 8:19pm UTC](https://discourse.julialang.org/t/build-function-from-differential-equation/58276 "2021-04-01T20:19:15Z")

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I tried the example from Symbolics.jl but ran into a problem: using Symbolics function lotka\_volterra!(du, u, p, t) x, y = u α, β, δ, γ = p du\[1\] = dx = α\*x - β\*x\*y du\[2\] = dy = -δ\*y + γ\*x\*y end @variables t du\[…

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## [Plots.jl plot window launched from a signal within Gtk.jl does not open—how to fix?](https://discourse.julialang.org/t/plots-jl-plot-window-launched-from-a-signal-within-gtk-jl-does-not-open-how-to-fix/58384)

<div class="topic-metadata">

**Author:** [@cdknight](https://discourse.julialang.org/u/cdknight)\
**Replies:** 1\
**Last updated:** [April 1, 2021, 8:18pm UTC](https://discourse.julialang.org/t/plots-jl-plot-window-launched-from-a-signal-within-gtk-jl-does-not-open-how-to-fix/58384 "2021-04-01T20:18:29Z")

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Hi, I’m new here (and to the Julia programming language in general), and hopefully this is the right category. Anyway, I’m attempting to make a GUI to facilitate some visualisation that I’m doing. What I want is to click…

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## [Change Plots.jl backend dynamically](https://discourse.julialang.org/t/change-plots-jl-backend-dynamically/58240)

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**Author:** [@HugoTrentesaux](https://discourse.julialang.org/u/HugoTrentesaux)\
**Replies:** 3\
**Last updated:** [April 1, 2021, 6:21pm UTC](https://discourse.julialang.org/t/change-plots-jl-backend-dynamically/58240 "2021-04-01T18:21:34Z")

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I want to plot a figure using all backends. I do this: function plots\_all\_formats() plots("png") plots("html") plots("svg") end function plots(format) # load data # ... if format == "html" …

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## [CUDA : vectorization not working with functions of complex argument](https://discourse.julialang.org/t/cuda-vectorization-not-working-with-functions-of-complex-argument/58375)

<div class="topic-metadata">

**Author:** [@anscoil](https://discourse.julialang.org/u/anscoil)\
**Replies:** 4\
**Last updated:** [April 1, 2021, 6:13pm UTC](https://discourse.julialang.org/t/cuda-vectorization-not-working-with-functions-of-complex-argument/58375 "2021-04-01T18:13:51Z")

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Hi, Before stating my problem, I would like to say that I’m a fully enthusiastic and convinced Julia user, and to thank the developers for their awesome work. The CUDA module is especially of great help to write fast c…

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## [Error with training decoupled NODEs](https://discourse.julialang.org/t/error-with-training-decoupled-nodes/58311)

<div class="topic-metadata">

**Author:** [@jvkoch](https://discourse.julialang.org/u/jvkoch)\
**Replies:** 1\
**Last updated:** [April 1, 2021, 12:35pm UTC](https://discourse.julialang.org/t/error-with-training-decoupled-nodes/58311 "2021-04-01T12:35:12Z")

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I’m attempting to train two decoupled neural ODEs simultaneously. Although decoupled, these ODEs interact through a coupled loss function (not shown). I have constructed this in two ways: 1) by writing two separate ODEPr…

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## [How can I feed sequences of different lengths though a RNN and still have it be differentiable in Flux? (Minimal example included)](https://discourse.julialang.org/t/how-can-i-feed-sequences-of-different-lengths-though-a-rnn-and-still-have-it-be-differentiable-in-flux-minimal-example-included/58340)

<div class="topic-metadata">

**Author:** [@DevJac](https://discourse.julialang.org/u/DevJac)\
**Replies:** 0\
**Last updated:** [April 1, 2021, 3:05am UTC](https://discourse.julialang.org/t/how-can-i-feed-sequences-of-different-lengths-though-a-rnn-and-still-have-it-be-differentiable-in-flux-minimal-example-included/58340 "2021-04-01T03:05:34Z")

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I have several matrices of several different lengths. I want to feed these matrices though a RNN using Flux, however, I haven’t been able to do so. Everything I’ve tried either uses a lot of memory during the backward pa…

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## [Dpylr do equivalent in query.jl standalone syntax?](https://discourse.julialang.org/t/dpylr-do-equivalent-in-query-jl-standalone-syntax/24745)

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**Author:** [@tlnagy](https://discourse.julialang.org/u/tlnagy)\
**Replies:** 10\
**Last updated:** [March 31, 2021, 11:34pm UTC](https://discourse.julialang.org/t/dpylr-do-equivalent-in-query-jl-standalone-syntax/24745 "2021-03-31T23:34:23Z")

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I love Query.jl’s standalone syntax, but I’m having trouble with finding something comparable to dplyr’s do syntax. Essentially a lot of what I need to do is compute an average/median/whatever of a group and then normali…

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## [DArray in Dagger vs DistributedArrays](https://discourse.julialang.org/t/darray-in-dagger-vs-distributedarrays/58330)

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**Author:** [@nucklass](https://discourse.julialang.org/u/nucklass)\
**Replies:** 0\
**Last updated:** [March 31, 2021, 9:23pm UTC](https://discourse.julialang.org/t/darray-in-dagger-vs-distributedarrays/58330 "2021-03-31T21:23:50Z")

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Hi all, Was looking over some options for making a project of mine run in parallel and happened to notice both Dagger and DistributedArrays export a DArray type. Anyone have any insights as to the difference between the…

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## [Robust heuristic for binding SOC without exact solution](https://discourse.julialang.org/t/robust-heuristic-for-binding-soc-without-exact-solution/58321)

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**Author:** [@lgo](https://discourse.julialang.org/u/lgo)\
**Replies:** 1\
**Last updated:** [March 31, 2021, 8:56pm UTC](https://discourse.julialang.org/t/robust-heuristic-for-binding-soc-without-exact-solution/58321 "2021-03-31T20:56:21Z")

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I’m solving a large number of LPs with a single second-order cone constraint. For each of these problems, I want to check, if the SOC is binding. To keep the run-time short, I do not want to obtain an exact solution or c…

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## [Using Plots for the first time](https://discourse.julialang.org/t/using-plots-for-the-first-time/58289)

<div class="topic-metadata">

**Author:** [@erlebach1](https://discourse.julialang.org/u/erlebach1)\
**Replies:** 7\
**Last updated:** [March 31, 2021, 8:25pm UTC](https://discourse.julialang.org/t/using-plots-for-the-first-time/58289 "2021-03-31T20:25:14Z")

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I just installed Julia 1.6 and noted the much faster compile times. Thanks! When executing using Plots for the first time, Julia when through a whole series of compiling steps. Here is a small piece of what scrolled by: …

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## [\[Julia OpenCV Binding\] no method matching jlopencv\_core\_Mat\_mutable\_data in split function](https://discourse.julialang.org/t/julia-opencv-binding-no-method-matching-jlopencv-core-mat-mutable-data-in-split-function/58284)

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**Author:** [@erwanlecarpentier](https://discourse.julialang.org/u/erwanlecarpentier)\
**Replies:** 0\
**Last updated:** [March 31, 2021, 10:25am UTC](https://discourse.julialang.org/t/julia-opencv-binding-no-method-matching-jlopencv-core-mat-mutable-data-in-split-function/58284 "2021-03-31T10:25:55Z")

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Hey! I get an error while using the split function of this Julia OpenCV Binding. Here is the code: using OpenCV m = OpenCV.imread("/absolute/path/to/image.png") OpenCV.split(m) And the error: MethodError: no method …

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## [Alternative to Netica for Bayesian Modeling](https://discourse.julialang.org/t/alternative-to-netica-for-bayesian-modeling/58265)

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**Author:** [@erlebach1](https://discourse.julialang.org/u/erlebach1)\
**Replies:** 1\
**Last updated:** [March 31, 2021, 3:04pm UTC](https://discourse.julialang.org/t/alternative-to-netica-for-bayesian-modeling/58265 "2021-03-31T15:04:47Z")

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Hi, Does anybody know of a good package the duplicates or extends the functionality of Netica (commercial software) to model Bayesian networks? Would Forney.jl or Turing.jl be appropriate to this task? Thank you.

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## [ForwardDiff of function with internal derivatives using CuArrays](https://discourse.julialang.org/t/forwarddiff-of-function-with-internal-derivatives-using-cuarrays/58178)

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**Author:** [@RynoLaubscher](https://discourse.julialang.org/u/RynoLaubscher)\
**Replies:** 8\
**Last updated:** [March 31, 2021, 12:13pm UTC](https://discourse.julialang.org/t/forwarddiff-of-function-with-internal-derivatives-using-cuarrays/58178 "2021-03-31T12:13:06Z")

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Hi All, I am struggling a bit with a ForwardDiff problem on GPU. I would like to determine the gradients of a loss function which internally uses Zygote to calculate gradients. I can get it to work perfectly on CPU but w…

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## [\`plan\_rfft\` together used with \`mul!\` and \`@view\` complains about wrong-strides-output](https://discourse.julialang.org/t/plan-rfft-together-used-with-mul-and-view-complains-about-wrong-strides-output/58215)

<div class="topic-metadata">

**Author:** [@roflmaostc](https://discourse.julialang.org/u/roflmaostc)\
**Replies:** 24\
**Last updated:** [March 30, 2021, 10:24pm UTC](https://discourse.julialang.org/t/plan-rfft-together-used-with-mul-and-view-complains-about-wrong-strides-output/58215 "2021-03-30T22:24:47Z")

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Hey, initially I wanted to have rfft! but since it doesn’t exist, I tried the workaround mentioned in this discourse discussion. However, mul! complains when used with a plan\_rfft generated matrix: using LinearAlgebra…

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## [Linearization](https://discourse.julialang.org/t/linearization/58167)

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**Author:** [@user1200](https://discourse.julialang.org/u/user1200)\
**Replies:** 3\
**Last updated:** [March 30, 2021, 10:09pm UTC](https://discourse.julialang.org/t/linearization/58167 "2021-03-30T22:09:33Z")

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Hi I have simple objective function (goal), solving with Ipopt for example: Min, sum (sin(data\[i\]\*x) for i=1:length(data) ) I was just curious if there is some way/wrap to achieve : maximize linearity of process to…

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## [Rename a row in DataFrames?](https://discourse.julialang.org/t/rename-a-row-in-dataframes/58261)

<div class="topic-metadata">

**Author:** [@Albert\_Zevelev](https://discourse.julialang.org/u/Albert_Zevelev)\
**Replies:** 1\
**Last updated:** [March 30, 2021, 8:18pm UTC](https://discourse.julialang.org/t/rename-a-row-in-dataframes/58261 "2021-03-30T20:18:34Z")

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Is it possible to rename a row in DataFrames.jl? Currently it looks like rows are numbered by default 1:n. The function rename!() only changes column names, not row names. My hack is to add a column w/ my desired row …

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## [To understand neural ODE](https://discourse.julialang.org/t/to-understand-neural-ode/58236)

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**Author:** [@vavrines](https://discourse.julialang.org/u/vavrines)\
**Replies:** 5\
**Last updated:** [March 30, 2021, 6:37pm UTC](https://discourse.julialang.org/t/to-understand-neural-ode/58236 "2021-03-30T18:37:42Z")

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I find I still don’t fully understand neural ordinary differential equations. As shown in literature (Lu et al., 2017; Haber and Ruthotto, 2017; Chen el al., 2018), a sequence of transformations h(t+1) = h(t) + f(h,th…

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## [Distribution cdf calculation](https://discourse.julialang.org/t/distribution-cdf-calculation/58252)

<div class="topic-metadata">

**Author:** [@statspy](https://discourse.julialang.org/u/statspy)\
**Replies:** 2\
**Last updated:** [March 30, 2021, 6:20pm UTC](https://discourse.julialang.org/t/distribution-cdf-calculation/58252 "2021-03-30T18:20:15Z")

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i have the following code that i am using and its working: using Distributions d=Exponential(1000) for i in collect(100:100:1000) print(i,"-\>",cdf(d,i) end The code it working properly. What i need now…

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