# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1421

[Latest](https://discourse.julialang.org/latest.md) · [Categories](https://discourse.julialang.org/categories.md) · [Tags](https://discourse.julialang.org/tags.md)

**Page:** 1422

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## [Activating a separate environment](https://discourse.julialang.org/t/activating-a-separate-environment/59515)

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**Author:** [@HerAdri](https://discourse.julialang.org/u/HerAdri)\
**Replies:** 2\
**Last updated:** [April 18, 2021, 8:15am UTC](https://discourse.julialang.org/t/activating-a-separate-environment/59515 "2021-04-18T08:15:12Z")

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how to activate a separate environment for julia 1.6.0 from julia 1.5.4? (@v1.6) pkg\> activate env1.6 Activating new environment at \`C:\\Users\\hermesr\\env1.6\\Project.toml\` (env1.6) pkg\> add Plots Updating registry…

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## [Getting problem data from jump model (semidefinite programming, etc.)](https://discourse.julialang.org/t/getting-problem-data-from-jump-model-semidefinite-programming-etc/59327)

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**Author:** [@Thomas](https://discourse.julialang.org/u/Thomas)\
**Replies:** 2\
**Last updated:** [April 18, 2021, 7:42am UTC](https://discourse.julialang.org/t/getting-problem-data-from-jump-model-semidefinite-programming-etc/59327 "2021-04-18T07:42:53Z")

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Hi everyone, after a quick search here and the API, I have not seen this question addressed to my liking so let me raise it: How to get the problem data in canonical form min dot(C,x) subject to Ax=b, that is from a mo…

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## [Usage of non-gzip files in Artifacts](https://discourse.julialang.org/t/usage-of-non-gzip-files-in-artifacts/48298)

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**Author:** [@racinmat](https://discourse.julialang.org/u/racinmat)\
**Replies:** 3\
**Last updated:** [April 18, 2021, 7:04am UTC](https://discourse.julialang.org/t/usage-of-non-gzip-files-in-artifacts/48298 "2021-04-18T07:04:00Z")

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Currently, Pkg.Artifacts assume downloaded file is gzipped and try to unzip it during artifact"a\_name". But some packages need to download files as artifacts, which are not archives. Is there way to add non-archives to A…

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## [Overwrite default constructor](https://discourse.julialang.org/t/overwrite-default-constructor/59520)

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**Author:** [@oyczyco13](https://discourse.julialang.org/u/oyczyco13)\
**Replies:** 2\
**Last updated:** [April 18, 2021, 6:30am UTC](https://discourse.julialang.org/t/overwrite-default-constructor/59520 "2021-04-18T06:30:42Z")

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Is it possible to overwrite the default constructor like: struct A field1 field2 field3 end function A(f1, f2, f3) # do some operation here like log / parameters inspection # return a…

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## [Priors for generated quantities in Turing?](https://discourse.julialang.org/t/priors-for-generated-quantities-in-turing/57572)

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**Author:** [@opera\_malenky](https://discourse.julialang.org/u/opera_malenky)\
**Replies:** 7\
**Last updated:** [April 18, 2021, 6:18am UTC](https://discourse.julialang.org/t/priors-for-generated-quantities-in-turing/57572 "2021-04-18T06:18:11Z")

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I have a Turing model where I need (in part) to do something like this: @model test() = begin x = ones(10) sigma ~ InverseGamma(1, 1) x ~ Normal(0, sigma) end m1 = sample(test(), NUTS(0.65), 1000) I was a …

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## [Is it possble for Julia to overwrite how to get field](https://discourse.julialang.org/t/is-it-possble-for-julia-to-overwrite-how-to-get-field/59507)

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**Author:** [@oyczyco13](https://discourse.julialang.org/u/oyczyco13)\
**Replies:** 6\
**Last updated:** [April 18, 2021, 2:40am UTC](https://discourse.julialang.org/t/is-it-possble-for-julia-to-overwrite-how-to-get-field/59507 "2021-04-18T02:40:57Z")

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struct A obj::B field1 field2 field3 end struct B field4 field5 end b = B(4, 5) a = A(b, 1, 2 ,3) a.field4 I expect a is able to get field4 from a.b (if there is one) by calling a.field4, just…

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## [Missing module documentation under Requires.jl](https://discourse.julialang.org/t/missing-module-documentation-under-requires-jl/58454)

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**Author:** [@henry2004y](https://discourse.julialang.org/u/henry2004y)\
**Replies:** 1\
**Last updated:** [April 18, 2021, 12:28am UTC](https://discourse.julialang.org/t/missing-module-documentation-under-requires-jl/58454 "2021-04-18T00:28:25Z")

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Hello, I am developing a data processing package. This package contains plotting functionalities from PyPlot.jl, but I don’t want to include that as an explicit dependency, so I choose to use Requires.jl to accomplish t…

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## [Trying to understand jll dependency version](https://discourse.julialang.org/t/trying-to-understand-jll-dependency-version/59504)

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**Author:** [@Egwene\_al\_Vere](https://discourse.julialang.org/u/Egwene_al_Vere)\
**Replies:** 1\
**Last updated:** [April 18, 2021, 12:11am UTC](https://discourse.julialang.org/t/trying-to-understand-jll-dependency-version/59504 "2021-04-18T00:11:12Z")

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This comes up in my testing of the current nightly, v1.7, where using DifferentialEquations fails due to one of its dependencies (Sundials). This has been reported by someone here The gist might be: The current Sundi…

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## [Unpacking Python's asterisk operator in Julia](https://discourse.julialang.org/t/unpacking-pythons-asterisk-operator-in-julia/59498)

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**Author:** [@amm](https://discourse.julialang.org/u/amm)\
**Replies:** 2\
**Last updated:** [April 17, 2021, 8:59pm UTC](https://discourse.julialang.org/t/unpacking-pythons-asterisk-operator-in-julia/59498 "2021-04-17T20:59:57Z")

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Hi everyone, I’ve been using Python recently, and I’ve discovered the asterisk operator, which expands the elements of an array where it’s used. For example, the two following usages of the variable a are equivalent, bei…

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## [Same ODEProblem has differente results when variable is Float64 and Vector{Float64}](https://discourse.julialang.org/t/same-odeproblem-has-differente-results-when-variable-is-float64-and-vector-float64/59477)

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**Author:** [@Rafael\_FC](https://discourse.julialang.org/u/Rafael_FC)\
**Replies:** 2\
**Last updated:** [April 17, 2021, 8:08pm UTC](https://discourse.julialang.org/t/same-odeproblem-has-differente-results-when-variable-is-float64-and-vector-float64/59477 "2021-04-17T20:08:12Z")

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Hello! I’m having trouble with the following code. As of now it’s working fine, but if I change y0 (Float64) to y0\[1\] (Vector{Float64}) and dy to dy\[1\], it returns a wrong result. Since it’s a simple problem I must be …

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## [Batch time-series input for RNN](https://discourse.julialang.org/t/batch-time-series-input-for-rnn/59469)

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**Author:** [@Sunny](https://discourse.julialang.org/u/Sunny)\
**Replies:** 1\
**Last updated:** [April 17, 2021, 8:07pm UTC](https://discourse.julialang.org/t/batch-time-series-input-for-rnn/59469 "2021-04-17T20:07:49Z")

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How to form and feed a proper batch to feed to RNN? It is possible to apply RNN to batch of one data point time-series inputs: # single sample rnn = RNN(2,3) seq = ones(Float32,(2,10)) rnn(seq) # apply to 10 sample in…

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## [Delete all rows which have null values/missing values in 'all' the columns](https://discourse.julialang.org/t/delete-all-rows-which-have-null-values-missing-values-in-all-the-columns/59489)

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**Author:** [@harneet411](https://discourse.julialang.org/u/harneet411)\
**Replies:** 1\
**Last updated:** [April 17, 2021, 6:02pm UTC](https://discourse.julialang.org/t/delete-all-rows-which-have-null-values-missing-values-in-all-the-columns/59489 "2021-04-17T18:02:28Z")

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I am trying to find a similar functionality like in Python where in I can delete the rows which have ‘all’ null values in a row - code in python - Using Pandas dataframe ‘closed\_prices’ closed\_prices.dropna(axis=0, how…

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## [Difficulty with Downloading IJulia](https://discourse.julialang.org/t/difficulty-with-downloading-ijulia/59484)

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**Author:** [@p.dawson](https://discourse.julialang.org/u/p.dawson)\
**Replies:** 2\
**Last updated:** [April 17, 2021, 5:51pm UTC](https://discourse.julialang.org/t/difficulty-with-downloading-ijulia/59484 "2021-04-17T17:51:14Z")

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I have bought new computer today with small SSD and a 1TB HDD. Have already downloaded Python and Anaconda. Want to use Julia in Jupyter notebooks. Downloaded Julia. No Problem. Attempted to download IJulia using Package…

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## [Julia 1.6.1 testing period](https://discourse.julialang.org/t/julia-1-6-1-testing-period/59490)

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**Author:** [@ararslan](https://discourse.julialang.org/u/ararslan)\
**Replies:** 0\
**Last updated:** [April 17, 2021, 5:46pm UTC](https://discourse.julialang.org/t/julia-1-6-1-testing-period/59490 "2021-04-17T17:46:40Z")

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The release-1.6 branch on the Julia repository now contains the set of commits we’re planning to tag as v1.6.1, the first patch release in the 1.6 series. The list of commits included since v1.6.0 is available here. As a…

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## [Trying to debug embedding of Julia in a JUCE (VST) audio plugin](https://discourse.julialang.org/t/trying-to-debug-embedding-of-julia-in-a-juce-vst-audio-plugin/58968)

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**Author:** [@toivo](https://discourse.julialang.org/u/toivo)\
**Replies:** 2\
**Last updated:** [April 17, 2021, 5:45pm UTC](https://discourse.julialang.org/t/trying-to-debug-embedding-of-julia-in-a-juce-vst-audio-plugin/58968 "2021-04-17T17:45:10Z")

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Hi! I’m trying to embed Julia into a VST plugin (using the JUCE framework) on windows. JUCE provides several build targets, and the standalone target works fine (after some tweaks related to embedding Julia on windows).…

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## [Julia is Eight times Slower than Go on Numerical Scheme](https://discourse.julialang.org/t/julia-is-eight-times-slower-than-go-on-numerical-scheme/59383)

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**Author:** [@ejolson](https://discourse.julialang.org/u/ejolson)\
**Replies:** 31\
**Last updated:** [April 17, 2021, 5:29pm UTC](https://discourse.julialang.org/t/julia-is-eight-times-slower-than-go-on-numerical-scheme/59383 "2021-04-17T17:29:47Z")

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Here is a run of the Julia code conjulia -- Energy Conserving IRK Scheme y(0)=\[1.0, 1.0, 1.0\] p n h E(100) dE(100) error 7 128 7.8125000e-01 3.0000000e+00 0.00…

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## [Why is big(0.5) printed as 0.50?](https://discourse.julialang.org/t/why-is-big-0-5-printed-as-0-50/59395)

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**Author:** [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Replies:** 6\
**Last updated:** [April 17, 2021, 5:06pm UTC](https://discourse.julialang.org/t/why-is-big-0-5-printed-as-0-50/59395 "2021-04-17T17:06:04Z")

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I’m not sure if this is the intended behavior: julia\> 0.5 0.5 julia\> big(0.5) 0.50 julia\> big(0.5) == 0.5 true Why the extra 0 at the end for a BigFloat?

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## [First Julia Meetup in Canberra, Australia](https://discourse.julialang.org/t/first-julia-meetup-in-canberra-australia/59485)

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**Author:** [@mohamed82008](https://discourse.julialang.org/u/mohamed82008)\
**Replies:** 0\
**Last updated:** [April 17, 2021, 5:14pm UTC](https://discourse.julialang.org/t/first-julia-meetup-in-canberra-australia/59485 "2021-04-17T17:14:40Z")

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Hi everyone, I am happy to announce the first Julia meetup in Canberra, Australia. It will be online so people can join from anywhere with a compatible timezone. This will be a beginner-friendly meetup discussing useful…

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## [Julia package for dithering images?](https://discourse.julialang.org/t/julia-package-for-dithering-images/56844)

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**Author:** [@Phil\_Tomson](https://discourse.julialang.org/u/Phil_Tomson)\
**Replies:** 3\
**Last updated:** [April 17, 2021, 4:58pm UTC](https://discourse.julialang.org/t/julia-package-for-dithering-images/56844 "2021-04-17T16:58:41Z")

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Are there any Julia packages for dithering images? Specifically Floyd-Steinberg dithering? I noticed this one: GitHub - xianrenb/DitherImage.jl: Simple Julia Package for Image Dithering But it hasn’t been updated in 5 …

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## [True power set of a set is slower than power array of array](https://discourse.julialang.org/t/true-power-set-of-a-set-is-slower-than-power-array-of-array/59464)

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**Author:** [@Wei\_Yang](https://discourse.julialang.org/u/Wei_Yang)\
**Replies:** 3\
**Last updated:** [April 17, 2021, 4:34pm UTC](https://discourse.julialang.org/t/true-power-set-of-a-set-is-slower-than-power-array-of-array/59464 "2021-04-17T16:34:49Z")

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I’m trying to create a power set function with only set operations, but it turns out to be much slower than the array version. I wonder why this is the case, and how to make the Set version as fast as the array version. …

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## [Gradient not updating in call to optimize (Optim.jl)](https://discourse.julialang.org/t/gradient-not-updating-in-call-to-optimize-optim-jl/59448)

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**Author:** [@marcus-waldman](https://discourse.julialang.org/u/marcus-waldman)\
**Replies:** 2\
**Last updated:** [April 17, 2021, 4:03pm UTC](https://discourse.julialang.org/t/gradient-not-updating-in-call-to-optimize-optim-jl/59448 "2021-04-17T16:03:57Z")

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I’m trying to use the optimize function as part of the Optim.jl package with gradients that I provide. The problem I am having is that the function isn’t actually iterating–it simply computes the objective function once …

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## [Change directory before running an external command](https://discourse.julialang.org/t/change-directory-before-running-an-external-command/59479)

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**Author:** [@curious](https://discourse.julialang.org/u/curious)\
**Replies:** 2\
**Last updated:** [April 17, 2021, 3:11pm UTC](https://discourse.julialang.org/t/change-directory-before-running-an-external-command/59479 "2021-04-17T15:11:52Z")

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I have a julia file, say FileIwantToRun.jl in many folders/directories. I want to write a script that visits each of these directories and runs this file from those directories (it outputs a file that I want it to save i…

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## [Orientation of 3d globe makie](https://discourse.julialang.org/t/orientation-of-3d-globe-makie/59478)

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**Author:** [@gdkrmr](https://discourse.julialang.org/u/gdkrmr)\
**Replies:** 0\
**Last updated:** [April 17, 2021, 2:26pm UTC](https://discourse.julialang.org/t/orientation-of-3d-globe-makie/59478 "2021-04-17T14:26:22Z")

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I am plotting a global data product on a 3d globe using Makie using with code below (sorry for not making this reproducible): m = uv\_normal\_mesh(GeometryBasics.Tesselation(Sphere(Point3f0(0), 6371000f0), 200)) scene = m…

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## [Plots: where to find the list of available fonts? Is it possible to set all fonts simultaneously](https://discourse.julialang.org/t/plots-where-to-find-the-list-of-available-fonts-is-it-possible-to-set-all-fonts-simultaneously/59451)

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**Author:** [@curious](https://discourse.julialang.org/u/curious)\
**Replies:** 6\
**Last updated:** [April 17, 2021, 2:00pm UTC](https://discourse.julialang.org/t/plots-where-to-find-the-list-of-available-fonts-is-it-possible-to-set-all-fonts-simultaneously/59451 "2021-04-17T14:00:08Z")

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I am using Plots.jl to create some plots with the default backend (I think it is the gr backend). I know that I can set say the title font and the legend font to say “computer modern” using the command: Plots.default(ti…

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## [What is the equivalent Julia code for this code in Python using requests?](https://discourse.julialang.org/t/what-is-the-equivalent-julia-code-for-this-code-in-python-using-requests/59468)

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**Author:** [@Nash](https://discourse.julialang.org/u/Nash)\
**Replies:** 4\
**Last updated:** [April 17, 2021, 12:31pm UTC](https://discourse.julialang.org/t/what-is-the-equivalent-julia-code-for-this-code-in-python-using-requests/59468 "2021-04-17T12:31:31Z")

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In attempt to use a new service that provides plenty of Python examples, I would like to know the equivalent to the following in Julia. Hopefully I can then work through the remaining examples myself: import requests h…

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## [How to use \`iterate(s::Stack)\` and \`Iterators.reverse(s::Stack{T})\` for Stack and Queue in DataStructures.jl?](https://discourse.julialang.org/t/how-to-use-iterate-s-stack-and-iterators-reverse-s-stack-t-for-stack-and-queue-in-datastructures-jl/59394)

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**Author:** [@vladgladkikh](https://discourse.julialang.org/u/vladgladkikh)\
**Replies:** 7\
**Last updated:** [April 17, 2021, 12:06pm UTC](https://discourse.julialang.org/t/how-to-use-iterate-s-stack-and-iterators-reverse-s-stack-t-for-stack-and-queue-in-datastructures-jl/59394 "2021-04-17T12:06:51Z")

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I am reading documentation for DataStructures.jl, namely this page: Stack and Queue · DataStructures.jl and cannot figure out how to use iterate(s::Stack) and Iterators.reverse(s::Stack{T})? I try this: s = Stack{Int}(…

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## [GridInterpolations.jl is not differentiable](https://discourse.julialang.org/t/gridinterpolations-jl-is-not-differentiable/58403)

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**Author:** [@jvkoch](https://discourse.julialang.org/u/jvkoch)\
**Replies:** 1\
**Last updated:** [April 17, 2021, 11:42am UTC](https://discourse.julialang.org/t/gridinterpolations-jl-is-not-differentiable/58403 "2021-04-17T11:42:08Z")

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I’m attempting to train two neural odes simultaneously that interact through the definition of a loss function. My training data is a 2d array. The goal here is to have one ODE describe the “path” through the 2D data arr…

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## [Write access to a variable in a module](https://discourse.julialang.org/t/write-access-to-a-variable-in-a-module/59025)

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**Author:** [@Eben60](https://discourse.julialang.org/u/Eben60)\
**Replies:** 6\
**Last updated:** [April 17, 2021, 11:32am UTC](https://discourse.julialang.org/t/write-access-to-a-variable-in-a-module/59025 "2021-04-17T11:32:11Z")

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module Mdl b1 = false end import .Mdl.b1 julia\> b1 false julia\> b1=true ERROR: cannot assign a value to variable Mdl.b1 from module Main Stacktrace: \[1\] top-level scope @ none:1 Why? ( I know, I can use a setter…

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## [FrankWolfe.jl: convex-constrained non-linear optimization at scale](https://discourse.julialang.org/t/frankwolfe-jl-convex-constrained-non-linear-optimization-at-scale/59472)

<div class="topic-metadata">

**Author:** [@mbesancon](https://discourse.julialang.org/u/mbesancon)\
**Replies:** 2\
**Last updated:** [April 17, 2021, 11:14am UTC](https://discourse.julialang.org/t/frankwolfe-jl-convex-constrained-non-linear-optimization-at-scale/59472 "2021-04-17T11:14:31Z")

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We are glad to have released FrankWolfe.jl, a package implementing several variants of the Frank-Wolfe / Conditional Gradient algorithm. The method allows the optimization of arbitrary objective functions with first-ord…

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## [How to bring differential equations to wanted value with DiffEqFlux?](https://discourse.julialang.org/t/how-to-bring-differential-equations-to-wanted-value-with-diffeqflux/54167)

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**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 24\
**Last updated:** [April 17, 2021, 11:13am UTC](https://discourse.julialang.org/t/how-to-bring-differential-equations-to-wanted-value-with-diffeqflux/54167 "2021-04-17T11:13:38Z")

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Hello, I have a population system (bacteria/phages) that I have described with these ODEs that include the logistic factor: function sir!(du, u, p, t) # SIRl with logistic term μ, κ, φ, ω, η, β = p #= du\[1\]…

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