# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1026

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

**Page:** 1027

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## [Destructuring Type Parameters](https://discourse.julialang.org/t/destructuring-type-parameters/81881)

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**Author:** [@HashBrown](https://discourse.julialang.org/u/HashBrown)\
**Replies:** 3\
**Last updated:** [May 29, 2022, 11:43pm UTC](https://discourse.julialang.org/t/destructuring-type-parameters/81881 "2022-05-29T23:43:57Z")

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Is there any way to destructure type parameters when defining parametric types and methods. Something along the lines of struct Foo{U{T}} end # Examples Foo{Vector{Int}}() Foo{AbstractArray{Int}}() I know this parti…

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## [ReTest, module system issues](https://discourse.julialang.org/t/retest-module-system-issues/81885)

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**Author:** [@jcbritobr](https://discourse.julialang.org/u/jcbritobr)\
**Replies:** 26\
**Last updated:** [May 29, 2022, 11:22pm UTC](https://discourse.julialang.org/t/retest-module-system-issues/81885 "2022-05-29T23:22:39Z")

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Hello, good afternoon, I’m trying to test some modules, but I’m having issues with ReTest and the module system. I had this custom modules and is all added to “.” path. RunTests.jl file, I’m getting the UndefVarError: …

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## [Benchmarking Error, Invalid Active Developer Path](https://discourse.julialang.org/t/benchmarking-error-invalid-active-developer-path/81808)

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**Author:** [@rnayebi](https://discourse.julialang.org/u/rnayebi)\
**Replies:** 3\
**Last updated:** [May 29, 2022, 10:48pm UTC](https://discourse.julialang.org/t/benchmarking-error-invalid-active-developer-path/81808 "2022-05-29T22:48:32Z")

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Hi, I was following this lecture: Julia is fast! | JuliaAcademy (the one about benchmarking) and I was running into some problems. Here is the cell I ran and the error that I got. Also I just downloaded it from the …

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## [How to restrict type parameter to be subclass of a parameterized type](https://discourse.julialang.org/t/how-to-restrict-type-parameter-to-be-subclass-of-a-parameterized-type/81854)

<div class="topic-metadata">

**Author:** [@HashBrown](https://discourse.julialang.org/u/HashBrown)\
**Replies:** 1\
**Last updated:** [May 29, 2022, 9:15am UTC](https://discourse.julialang.org/t/how-to-restrict-type-parameter-to-be-subclass-of-a-parameterized-type/81854 "2022-05-29T09:15:18Z")

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I am looking to perform something like this: abstract type Foo{T} end struct Bar{T, U} \<: Foo{U} bar :: U end struct Baz{T} \<: Foo{U} where T \<: Foo{U} where U baz :: U end That is I would like to parameteriz…

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## [Converting PyTorch to Flux while keeping performance](https://discourse.julialang.org/t/converting-pytorch-to-flux-while-keeping-performance/81877)

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**Author:** [@Jarartur](https://discourse.julialang.org/u/Jarartur)\
**Replies:** 7\
**Last updated:** [May 29, 2022, 9:58pm UTC](https://discourse.julialang.org/t/converting-pytorch-to-flux-while-keeping-performance/81877 "2022-05-29T21:58:01Z")

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Hey, I am currently converting some models from pytorch to flux and can’t figure out why I am having performance issues. My function in PyTorch: def stiffness\_reg(x, idx): x\_nn = knn\_gather(x, idx) # basically ind…

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## [Sampling from Turing model combining discrete and continuous variables fails on second loop through the model](https://discourse.julialang.org/t/sampling-from-turing-model-combining-discrete-and-continuous-variables-fails-on-second-loop-through-the-model/81889)

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**Author:** [@Canaan\_Breiss](https://discourse.julialang.org/u/Canaan_Breiss)\
**Replies:** 0\
**Last updated:** [May 29, 2022, 9:35pm UTC](https://discourse.julialang.org/t/sampling-from-turing-model-combining-discrete-and-continuous-variables-fails-on-second-loop-through-the-model/81889 "2022-05-29T21:35:13Z")

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Hi, I’m trying to write a model that simultaneously estimates the mean of two underlying components, while also inferring component membership, with by-subject random intercepts. The data I have are synthetic, 120 subjec…

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## [Error in Pkg.update()](https://discourse.julialang.org/t/error-in-pkg-update/81837)

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**Author:** [@Raymond](https://discourse.julialang.org/u/Raymond)\
**Replies:** 3\
**Last updated:** [May 29, 2022, 8:18pm UTC](https://discourse.julialang.org/t/error-in-pkg-update/81837 "2022-05-29T20:18:31Z")

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What’s wrong with this problem? julia\> using Pkg julia\> Pkg.update() Updating registry at \`~/.julia/registries/General.toml\` ┌ Warning: could not download https://pkg.julialang.org/registries │ exception = Connec…

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## [Write function "show" for own multi-level structure](https://discourse.julialang.org/t/write-function-show-for-own-multi-level-structure/81882)

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**Author:** [@Yuri](https://discourse.julialang.org/u/Yuri)\
**Replies:** 2\
**Last updated:** [May 29, 2022, 7:35pm UTC](https://discourse.julialang.org/t/write-function-show-for-own-multi-level-structure/81882 "2022-05-29T19:35:47Z")

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I want to write a function Base.show for my structure Node: mutable struct Node keys::Vector vals::Vector count::Int end and which will display: nod = Node( \["a", "b", "c", "d"\], \[Node( \["…

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## [MethodError: objects of type Float64 are not callable](https://discourse.julialang.org/t/methoderror-objects-of-type-float64-are-not-callable/81876)

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**Author:** [@Hupdup](https://discourse.julialang.org/u/Hupdup)\
**Replies:** 2\
**Last updated:** [May 29, 2022, 6:04pm UTC](https://discourse.julialang.org/t/methoderror-objects-of-type-float64-are-not-callable/81876 "2022-05-29T18:04:11Z")

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Hi, when I want to update the weights of my main\_network, I always get this ERROR: MethodError: objects of type Float64 are not callable The Output is: -24.429102722601773 Float32\[-0.019576067, 0.08515469, -0.026…

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## [Stipple plotting markers with color](https://discourse.julialang.org/t/stipple-plotting-markers-with-color/81320)

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**Author:** [@monty](https://discourse.julialang.org/u/monty)\
**Replies:** 15\
**Last updated:** [May 29, 2022, 5:30pm UTC](https://discourse.julialang.org/t/stipple-plotting-markers-with-color/81320 "2022-05-29T17:30:08Z")

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How the markers can be plotted with color based on a third variable (in addition of x and y)? import Stipple import Stipple: @with\_kw, @reactors, R, ChannelName import Genie import StippleUI import StipplePlotly @Stipp…

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## [First actuarial example](https://discourse.julialang.org/t/first-actuarial-example/81863)

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**Author:** [@sbacelar](https://discourse.julialang.org/u/sbacelar)\
**Replies:** 4\
**Last updated:** [May 29, 2022, 2:40pm UTC](https://discourse.julialang.org/t/first-actuarial-example/81863 "2022-05-29T14:40:54Z")

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I found this little example in an actuarial book using R. set.seed(1) X \<- rexp(200, rate=1/100) print(X\[1:5\]) I know that rexp generates random deviates. How can I replicate this example in Julia? Using Distributions…

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## [Symbolics.jl: Compute determinant](https://discourse.julialang.org/t/symbolics-jl-compute-determinant/81866)

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**Author:** [@DanDoe](https://discourse.julialang.org/u/DanDoe)\
**Replies:** 2\
**Last updated:** [May 29, 2022, 1:28pm UTC](https://discourse.julialang.org/t/symbolics-jl-compute-determinant/81866 "2022-05-29T13:28:35Z")

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I would like to compute the determinant of a matrix involving a symbolic variable: using Symbolics I = # Identity matrix A = # Some non-trivial matrix @variables z aux = I - z \* A det(aux) This webpage claims that co…

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## [\[ANN\] New package KiteSimulators.jl](https://discourse.julialang.org/t/ann-new-package-kitesimulators-jl/81861)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 0\
**Last updated:** [May 29, 2022, 10:47am UTC](https://discourse.julialang.org/t/ann-new-package-kitesimulators-jl/81861 "2022-05-29T10:47:55Z")

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I am happy to announce the release of the meta-package KiteSimulators.jl, which bundles all the packages that are part of Julia Kite Power Tools. It is easy to install on Windows and Linux (hopefully also on Mac, I ca…

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## [How to embed a .png file in README.md](https://discourse.julialang.org/t/how-to-embed-a-png-file-in-readme-md/81859)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 3\
**Last updated:** [May 29, 2022, 10:50am UTC](https://discourse.julialang.org/t/how-to-embed-a-png-file-in-readme-md/81859 "2022-05-29T10:50:58Z")

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What is the best way of embedding a .png file in a README.md file for a package on Github? I currently use: \<p align="center"\>\<img src="./docs/kite\_power\_tools.png" width="500" /\>\</p\> That works fine on github: GitHub…

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## [Plotting a thematic map with a continuous color scale](https://discourse.julialang.org/t/plotting-a-thematic-map-with-a-continuous-color-scale/81695)

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**Author:** [@Brinkhuis](https://discourse.julialang.org/u/Brinkhuis)\
**Replies:** 9\
**Last updated:** [May 29, 2022, 10:19am UTC](https://discourse.julialang.org/t/plotting-a-thematic-map-with-a-continuous-color-scale/81695 "2022-05-29T10:19:31Z")

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I would like to plot a thematic map (choropleth) using Plots.jl. The DataFrame df I use has 3 columns: geometry, value1 and value2. The column geometry is of element type Polygon (data was read using the Shapefile packag…

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## [Rhombic Dodecahedron](https://discourse.julialang.org/t/rhombic-dodecahedron/81743)

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**Author:** [@Gravlax](https://discourse.julialang.org/u/Gravlax)\
**Replies:** 1\
**Last updated:** [May 29, 2022, 8:50am UTC](https://discourse.julialang.org/t/rhombic-dodecahedron/81743 "2022-05-29T08:50:09Z")

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Dear all, I was wondering whether there an existing package that allows to generate shapes such as rhombic dodecahedron. I am trying to make a 3D model (Cartesian regular mesh) in which I would like to identify cell ce…

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## [Pipeline for different columns](https://discourse.julialang.org/t/pipeline-for-different-columns/81494)

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**Author:** [@jfcal](https://discourse.julialang.org/u/jfcal)\
**Replies:** 11\
**Last updated:** [May 29, 2022, 9:08am UTC](https://discourse.julialang.org/t/pipeline-for-different-columns/81494 "2022-05-29T09:08:23Z")

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Hi everyone, I have mixed type data and want to apply different functions to different types in a pipeline. Like imputation with mean for continuous and knn imputation for categorical and so on… Is it possible with MLJ…

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## [Problems with USE\_SYSTEM\_LLVM](https://discourse.julialang.org/t/problems-with-use-system-llvm/81790)

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**Author:** [@wheeheee](https://discourse.julialang.org/u/wheeheee)\
**Replies:** 4\
**Last updated:** [May 29, 2022, 5:14am UTC](https://discourse.julialang.org/t/problems-with-use-system-llvm/81790 "2022-05-29T05:14:12Z")

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I was trying to build julia on master for Fedora x86\_64 with USE\_SYSTEM\_LLVM=1 toggled in Make.inc (nothing else modified). When I use make, the outputs stop until the line below and don’t progress for some time so I ctr…

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## [Send http request through specific network interface using HTTP.jl](https://discourse.julialang.org/t/send-http-request-through-specific-network-interface-using-http-jl/81777)

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**Author:** [@Anastas](https://discourse.julialang.org/u/Anastas)\
**Replies:** 2\
**Last updated:** [May 29, 2022, 5:08am UTC](https://discourse.julialang.org/t/send-http-request-through-specific-network-interface-using-http-jl/81777 "2022-05-29T05:08:50Z")

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Hello, every one I want to send request through specific network interface using HTTP.jl like it works in here . In lib python requests it works correct. Or if to use curl, request should look like this: curl --interfa…

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## [Does Julia has the similar command \`clear all\` or \`cls\` in matlab?](https://discourse.julialang.org/t/does-julia-has-the-similar-command-clear-all-or-cls-in-matlab/81809)

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**Author:** [@Raymond](https://discourse.julialang.org/u/Raymond)\
**Replies:** 8\
**Last updated:** [May 29, 2022, 1:03am UTC](https://discourse.julialang.org/t/does-julia-has-the-similar-command-clear-all-or-cls-in-matlab/81809 "2022-05-29T01:03:08Z")

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Dear all, Does Julia has the similar command clear all or cls in matlab? I want to clear all the variable or packages which are used.

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## [Extracting type parameters from type with many parameters](https://discourse.julialang.org/t/extracting-type-parameters-from-type-with-many-parameters/81843)

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**Author:** [@nsajko](https://discourse.julialang.org/u/nsajko)\
**Replies:** 6\
**Last updated:** [May 29, 2022, 12:07am UTC](https://discourse.julialang.org/t/extracting-type-parameters-from-type-with-many-parameters/81843 "2022-05-29T00:07:05Z")

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I’ve got a type with six type parameters, something like this: struct MyType{A \<: S, a0, a1, B \<: T, b0, b1} end My problem is that I want access to the type parameters in functions which take MyType values as argument…

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## [Reading and writing Apache arrow files](https://discourse.julialang.org/t/reading-and-writing-apache-arrow-files/81838)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 4\
**Last updated:** [May 28, 2022, 8:01pm UTC](https://discourse.julialang.org/t/reading-and-writing-apache-arrow-files/81838 "2022-05-28T20:01:40Z")

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Hello, I am writing my log files in apache arrow format using Arrow.jl User Manual · Arrow.jl Now I want to read it in Python, see Feather File Format — Apache Arrow v9.0.0 But the Python documentation mentions differ…

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## [How to control type conversion from python to julia](https://discourse.julialang.org/t/how-to-control-type-conversion-from-python-to-julia/81840)

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**Author:** [@StormSurge](https://discourse.julialang.org/u/StormSurge)\
**Replies:** 1\
**Last updated:** [May 28, 2022, 7:45pm UTC](https://discourse.julialang.org/t/how-to-control-type-conversion-from-python-to-julia/81840 "2022-05-28T19:45:53Z")

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I’m extremely new to Julia (started learning it yesterday) and I’m currently in the process of trying to create a Python client for a game called Adventure Land. I have the client working, but there’s a single process wi…

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## [Updating a value using a column](https://discourse.julialang.org/t/updating-a-value-using-a-column/81805)

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**Author:** [@anon69491625](https://discourse.julialang.org/u/anon69491625)\
**Replies:** 10\
**Last updated:** [May 28, 2022, 7:04pm UTC](https://discourse.julialang.org/t/updating-a-value-using-a-column/81805 "2022-05-28T19:04:26Z")

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I want to select a row from a dataframe and update a value on that row using a message received via zmq. So the message would provide Bucket = “bucket\_1” # this would add a new row to the empty dataframe field\_in =…

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## [Using serial ports](https://discourse.julialang.org/t/using-serial-ports/81604)

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**Author:** [@nhardy](https://discourse.julialang.org/u/nhardy)\
**Replies:** 8\
**Last updated:** [May 28, 2022, 7:04pm UTC](https://discourse.julialang.org/t/using-serial-ports/81604 "2022-05-28T19:04:12Z")

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So, I am trying to stream data from a device over a serial port (RS232 via USB) in realtime. I saw two packages to talk to serial ports, SerialPorts (a wrapper on the Python SerialPorts package) and LibSerialPorts (a wra…

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## [Training with Flux.jl on the GPU causes ArgumentError: cannot take the CPU address of a CuArray](https://discourse.julialang.org/t/training-with-flux-jl-on-the-gpu-causes-argumenterror-cannot-take-the-cpu-address-of-a-cuarray/81751)

<div class="topic-metadata">

**Author:** [@lfenzo](https://discourse.julialang.org/u/lfenzo)\
**Replies:** 4\
**Last updated:** [May 28, 2022, 4:30pm UTC](https://discourse.julialang.org/t/training-with-flux-jl-on-the-gpu-causes-argumenterror-cannot-take-the-cpu-address-of-a-cuarray/81751 "2022-05-28T16:30:54Z")

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Hello! I’m trying to train a neural network using Flux.jl on the GPU with CUDA.jl. My issue (see error below) is that there seems to be some problem during the data transfer process between the GPU and CPU which causes …

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## [Why do we need "GalacticOptim.instantiate\_function"?](https://discourse.julialang.org/t/why-do-we-need-galacticoptim-instantiate-function/81760)

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**Author:** [@mzhenirovskyy](https://discourse.julialang.org/u/mzhenirovskyy)\
**Replies:** 9\
**Last updated:** [May 28, 2022, 3:58pm UTC](https://discourse.julialang.org/t/why-do-we-need-galacticoptim-instantiate-function/81760 "2022-05-28T15:58:28Z")

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This example seems to work even without “instantiate\_function”. https://diffeqflux.sciml.ai/stable/examples/neural\_ode\_galacticoptim/ I can’t find any docs about “instantiate\_function”.

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## [Initiate an array of functions](https://discourse.julialang.org/t/initiate-an-array-of-functions/81834)

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**Author:** [@LeoK987](https://discourse.julialang.org/u/LeoK987)\
**Replies:** 4\
**Last updated:** [May 28, 2022, 3:15pm UTC](https://discourse.julialang.org/t/initiate-an-array-of-functions/81834 "2022-05-28T15:15:53Z")

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I have func1 and func2. When I create an array of the functions, like: julia\> A = \[func1, func2\] 2-element Vector{Function}: func1 (generic function with 4 methods) func2 (generic function with 4 methods) That is g…

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## [Solving Heat equation using Julia](https://discourse.julialang.org/t/solving-heat-equation-using-julia/81720)

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**Author:** [@Raed\_Maraabeh](https://discourse.julialang.org/u/Raed_Maraabeh)\
**Replies:** 5\
**Last updated:** [May 28, 2022, 2:06pm UTC](https://discourse.julialang.org/t/solving-heat-equation-using-julia/81720 "2022-05-28T14:06:44Z")

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Hi, I am new user of Julia and I want to use it for solving PDEs and ODEs numerically. I am trying to run examples that are available in Julia website or GitHub but I get error. For instance I want to run this example…

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## [Portable Julia](https://discourse.julialang.org/t/portable-julia/45339)

<div class="topic-metadata">

**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 22\
**Last updated:** [May 28, 2022, 1:36pm UTC](https://discourse.julialang.org/t/portable-julia/45339 "2022-05-28T13:36:55Z")

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I noticed that a portable Julia is now available for the Windows platform. I think this might lead to a Julia-on-a-stick, but a little bit more work is required, I think. I started putting together a bash script for th…

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