# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1559

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

**Page:** 1560

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## [Implementing finite difference with periodic B.C](https://discourse.julialang.org/t/implementing-finite-difference-with-periodic-b-c/50975)

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**Author:** [@yhchang](https://discourse.julialang.org/u/yhchang)\
**Replies:** 9\
**Last updated:** [November 30, 2020, 9:09pm UTC](https://discourse.julialang.org/t/implementing-finite-difference-with-periodic-b-c/50975 "2020-11-30T21:09:39Z")

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I am pretty new to Julia and ultimately I want to transfer my python code for solving a nonlinear PDE into Julia (and see whether I can get the speedup I hope). The PDE I want to solve is similar to a nonlinear heat equ…

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## [REPL Environment](https://discourse.julialang.org/t/repl-environment/50977)

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**Author:** [@vaeli](https://discourse.julialang.org/u/vaeli)\
**Replies:** 2\
**Last updated:** [November 30, 2020, 8:51pm UTC](https://discourse.julialang.org/t/repl-environment/50977 "2020-11-30T20:51:19Z")

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Hello! There is only a command for total refresh, or restart, to make it possible to create a class with different variables in Julia. Mathematically, it would help to have such command: "Store “Package1"” To have Ju…

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## [How to call wait on multiple Tasks?](https://discourse.julialang.org/t/how-to-call-wait-on-multiple-tasks/50981)

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**Author:** [@s-kap](https://discourse.julialang.org/u/s-kap)\
**Replies:** 3\
**Last updated:** [November 30, 2020, 7:46pm UTC](https://discourse.julialang.org/t/how-to-call-wait-on-multiple-tasks/50981 "2020-11-30T19:46:18Z")

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Hey all, I have some code that uses @spawn to generate ~50 tasks tasks=Vector{Task}() function process\_row\_group(range::Tuple{Int64,RangeMarker}) for col\_name in col\_names push!(tasks, Threads.@spawn proces…

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## [Documenter fails with ssh error](https://discourse.julialang.org/t/documenter-fails-with-ssh-error/50976)

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**Author:** [@Joris\_Pinkse](https://discourse.julialang.org/u/Joris_Pinkse)\
**Replies:** 9\
**Last updated:** [November 30, 2020, 7:24pm UTC](https://discourse.julialang.org/t/documenter-fails-with-ssh-error/50976 "2020-11-30T19:24:51Z")

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I’m trying to create my first package (using pkgtemplate) but am running into problems generating the documentation using Documenter. I’ve generated ssh keys using DocumenterTools and have stuck them in the indicated pl…

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## [Embed local image in Dash app with HTTP?](https://discourse.julialang.org/t/embed-local-image-in-dash-app-with-http/51004)

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**Author:** [@Iulian.Cioarca](https://discourse.julialang.org/u/Iulian.Cioarca)\
**Replies:** 3\
**Last updated:** [November 30, 2020, 7:19pm UTC](https://discourse.julialang.org/t/embed-local-image-in-dash-app-with-http/51004 "2020-11-30T19:19:14Z")

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I am developing a Dash.jl app and discovered that I cannot embed local pictures. One workaround I found is to somehow host images on a local server in order to display them, but I have no idea how to do that in Julia. M…

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## [Partitioning Around Medoids (PAM) in Julia](https://discourse.julialang.org/t/partitioning-around-medoids-pam-in-julia/50879)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 10\
**Last updated:** [November 30, 2020, 4:45pm UTC](https://discourse.julialang.org/t/partitioning-around-medoids-pam-in-julia/50879 "2020-11-30T16:45:20Z")

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I’m unable to find any package that implements this algorithm. I’m going to attempt to implement the algorithm myself but I’m not sure if I have the know-how to get it over the finish line, to be perfectly honest. Would …

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## [Adding multiple new columns to dataframe?](https://discourse.julialang.org/t/adding-multiple-new-columns-to-dataframe/50997)

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**Author:** [@LasseKatten](https://discourse.julialang.org/u/LasseKatten)\
**Replies:** 13\
**Last updated:** [November 30, 2020, 4:18pm UTC](https://discourse.julialang.org/t/adding-multiple-new-columns-to-dataframe/50997 "2020-11-30T16:18:01Z")

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Hi Previously, one could do the following to add new columns to a dataframe: df = Dataframe() df\[\[:col1, :col2, :col3\]\] = \[\] But nowadays, this yields the following error message: ERROR: MethodError: no method matchi…

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## [Best way to learn differentiable computing?](https://discourse.julialang.org/t/best-way-to-learn-differentiable-computing/50955)

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**Author:** [@StatisticalMouse](https://discourse.julialang.org/u/StatisticalMouse)\
**Replies:** 1\
**Last updated:** [November 30, 2020, 3:52pm UTC](https://discourse.julialang.org/t/best-way-to-learn-differentiable-computing/50955 "2020-11-30T15:52:28Z")

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What would be the best resource to get started? Also, what would be the ‘state of the art’ in this area right now?

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## [VSCode displaying error markers for positional arguments](https://discourse.julialang.org/t/vscode-displaying-error-markers-for-positional-arguments/50980)

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**Author:** [@Niclas\_Wiberg](https://discourse.julialang.org/u/Niclas_Wiberg)\
**Replies:** 1\
**Last updated:** [November 30, 2020, 2:52pm UTC](https://discourse.julialang.org/t/vscode-displaying-error-markers-for-positional-arguments/50980 "2020-11-30T14:52:36Z")

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I’m using the awesome Julia mode in VSCode, thanks for that! One slight issue however is that vscode seems to display incorrect error markers on some calls to functions with keyword arguments. Is it possible to get rid …

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## [MKL package installation failed: error during bootstrap](https://discourse.julialang.org/t/mkl-package-installation-failed-error-during-bootstrap/50992)

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**Author:** [@EconModeler](https://discourse.julialang.org/u/EconModeler)\
**Replies:** 0\
**Last updated:** [November 30, 2020, 1:16pm UTC](https://discourse.julialang.org/t/mkl-package-installation-failed-error-during-bootstrap/50992 "2020-11-30T13:16:28Z")

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Hello. I am using JuliaPro with Julia version 1.5.2. My computer OS is windows and the CPU is Intel(R) Core ™ i7-7500U CPU@2.70HGz, 2.9GHz. I would like to use Intel Math Kernel Library with Julia, so I tried to add t…

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## [Need help with Flux CUDA.jl warning and error message](https://discourse.julialang.org/t/need-help-with-flux-cuda-jl-warning-and-error-message/50146)

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**Author:** [@forestacorn](https://discourse.julialang.org/u/forestacorn)\
**Replies:** 7\
**Last updated:** [November 30, 2020, 12:49pm UTC](https://discourse.julialang.org/t/need-help-with-flux-cuda-jl-warning-and-error-message/50146 "2020-11-30T12:49:13Z")

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I need some help understanding the following Flux problem and hopefully finding a fix for it. When I run using Flux on my desktop system I get the following warning and error messages: ┌ Warning: This version of CUDA.j…

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## [How to use github & friends tools for package development in late 2020](https://discourse.julialang.org/t/how-to-use-github-friends-tools-for-package-development-in-late-2020/50984)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 1\
**Last updated:** [November 30, 2020, 11:11am UTC](https://discourse.julialang.org/t/how-to-use-github-friends-tools-for-package-development-in-late-2020/50984 "2020-11-30T11:11:23Z")

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I recall some weeks ago to have quickly read some topic, and having received some emails, dealing with some change of policy for some of the tools we use in package development (something related to cron). Now, I someho…

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## [Qrfact lufact functions not found in LinearAlgebra Pkg](https://discourse.julialang.org/t/qrfact-lufact-functions-not-found-in-linearalgebra-pkg/50966)

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**Author:** [@George\_Makroglou](https://discourse.julialang.org/u/George_Makroglou)\
**Replies:** 4\
**Last updated:** [November 30, 2020, 10:17am UTC](https://discourse.julialang.org/t/qrfact-lufact-functions-not-found-in-linearalgebra-pkg/50966 "2020-11-30T10:17:31Z")

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Hello, I’m actually new to Julia and trying many different tutorials along with the documentation in order to get a better understanding of the language until I start using it in a more fluent way. I’ve seen in one of th…

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## [Dotted pair operator .=\>](https://discourse.julialang.org/t/dotted-pair-operator/50978)

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**Author:** [@mzaffalon](https://discourse.julialang.org/u/mzaffalon)\
**Replies:** 1\
**Last updated:** [November 30, 2020, 8:32am UTC](https://discourse.julialang.org/t/dotted-pair-operator/50978 "2020-11-30T08:32:35Z")

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I just realized today that it is possible to create a dict with .=\>: julia\> Dict(\['a', 'b', 'c'\] .=\> 1:3) Dict{Char,Int64} with 3 entries: 'a' =\> 1 'c' =\> 3 'b' =\> 2 Dotted syntax for pairs: this made my day!

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## [Nested Pipes](https://discourse.julialang.org/t/nested-pipes/49573)

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**Author:** [@Lincoln\_Hannah](https://discourse.julialang.org/u/Lincoln_Hannah)\
**Replies:** 6\
**Last updated:** [November 30, 2020, 6:12am UTC](https://discourse.julialang.org/t/nested-pipes/49573 "2020-11-30T06:12:55Z")

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For a Pipe within a Pipe is there an \_ equivalent for the inner pipe ? \_\_ ? \_2 ?

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## [Using Optim.Options (Syntax)](https://discourse.julialang.org/t/using-optim-options-syntax/50930)

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**Author:** [@schubbiaschwilli](https://discourse.julialang.org/u/schubbiaschwilli)\
**Replies:** 1\
**Last updated:** [November 30, 2020, 5:22am UTC](https://discourse.julialang.org/t/using-optim-options-syntax/50930 "2020-11-30T05:22:43Z")

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Hello! I am fitting curves with 2 parameters and I’m using Optim.optimize; especially the LBFGS method because there are lower and upper bounds. —snip— Optim.optimize(par → Loss(Testdata, par), \[0.005, 0.00001\], \[1000…

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## [Auckland Julia meetup, Wednesday December 2](https://discourse.julialang.org/t/auckland-julia-meetup-wednesday-december-2/50970)

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**Author:** [@odow](https://discourse.julialang.org/u/odow)\
**Replies:** 3\
**Last updated:** [November 30, 2020, 4:12am UTC](https://discourse.julialang.org/t/auckland-julia-meetup-wednesday-december-2/50970 "2020-11-30T04:12:46Z")

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Tēnā koutou, We’re pleased to announce that, due to New Zealand’s Covid-free status, an in-person Julia meetup will take place Wednesday, December 2 at 4pm, hosted by the Department of Physics at the University of Auc…

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## [Performance of recursively building tuples](https://discourse.julialang.org/t/performance-of-recursively-building-tuples/50917)

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**Author:** [@Benny](https://discourse.julialang.org/u/Benny)\
**Replies:** 6\
**Last updated:** [November 30, 2020, 2:51am UTC](https://discourse.julialang.org/t/performance-of-recursively-building-tuples/50917 "2020-11-30T02:51:58Z")

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I was reading through the source code for broadcasting and CartesianIndices, and I noticed that there were many methods that recursively operated on tuples. I thought it strange because I thought iteration was more intui…

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## [Us-west.pkg.julialang.org is down. How to switch to east?](https://discourse.julialang.org/t/us-west-pkg-julialang-org-is-down-how-to-switch-to-east/50973)

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**Author:** [@tbenst](https://discourse.julialang.org/u/tbenst)\
**Replies:** 1\
**Last updated:** [November 30, 2020, 2:49am UTC](https://discourse.julialang.org/t/us-west-pkg-julialang-org-is-down-how-to-switch-to-east/50973 "2020-11-30T02:49:07Z")

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I cannot reach us-west.pkg.julialang.org, and it appears to be down: Us-west.pkg.julialang.org down? Current problems and status. How can I temporarily switch to https://us-east.pkg.julialang.org/? Edit: as a hack work…

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## [How is Julia written in Julia?](https://discourse.julialang.org/t/how-is-julia-written-in-julia/50918)

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**Author:** [@logankilpatrick](https://discourse.julialang.org/u/logankilpatrick)\
**Replies:** 9\
**Last updated:** [November 30, 2020, 1:18am UTC](https://discourse.julialang.org/t/how-is-julia-written-in-julia/50918 "2020-11-30T01:18:37Z")

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Hey all, I am broadly trying to understand how Julia as a language is written in Julia itself. Is the compiler what is enabling this or is there a different reason?

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## [Writing protobuf message to a websocket](https://discourse.julialang.org/t/writing-protobuf-message-to-a-websocket/50951)

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**Author:** [@Josiah\_Slack](https://discourse.julialang.org/u/Josiah_Slack)\
**Replies:** 0\
**Last updated:** [November 29, 2020, 5:56pm UTC](https://discourse.julialang.org/t/writing-protobuf-message-to-a-websocket/50951 "2020-11-29T17:56:26Z")

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I’m interested in writing a server process in julia that will periodically publish protocol buffer messages over a web socket. I’ve done a little naive experimenting, and haven’t gotten very far (did manage to get an err…

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## [$JULIA\_BINDIR is not set](https://discourse.julialang.org/t/julia-bindir-is-not-set/50950)

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**Author:** [@Ravinder\_Ram](https://discourse.julialang.org/u/Ravinder_Ram)\
**Replies:** 1\
**Last updated:** [November 29, 2020, 5:36pm UTC](https://discourse.julialang.org/t/julia-bindir-is-not-set/50950 "2020-11-29T17:36:55Z")

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what is JULIA\_BINDIR

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## [Stability Issues in Optim](https://discourse.julialang.org/t/stability-issues-in-optim/50949)

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**Author:** [@Gregor](https://discourse.julialang.org/u/Gregor)\
**Replies:** 0\
**Last updated:** [November 29, 2020, 5:30pm UTC](https://discourse.julialang.org/t/stability-issues-in-optim/50949 "2020-11-29T17:30:53Z")

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Hello, I am trying to optimize a simple linear system towards some known parameters and switched from the ADAMs optimizer to (L)BFGS. I didn’t change the problem/ode but for some reason the (L)BFGS optimizer runs in sev…

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## [Fitting Data](https://discourse.julialang.org/t/fitting-data/50938)

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**Author:** [@WEEZEERAE](https://discourse.julialang.org/u/WEEZEERAE)\
**Replies:** 1\
**Last updated:** [November 29, 2020, 3:40pm UTC](https://discourse.julialang.org/t/fitting-data/50938 "2020-11-29T15:40:13Z")

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Hello Community! I would like to know about which package you would recommend me to fit data sets, i.e received from a spectral analysis. Currently I am working with GnuPlot, but I guess there is a more accurate way to …

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## [\[ANN\] PubChemCrawler](https://discourse.julialang.org/t/ann-pubchemcrawler/50935)

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**Author:** [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Replies:** 0\
**Last updated:** [November 29, 2020, 2:03pm UTC](https://discourse.julialang.org/t/ann-pubchemcrawler/50935 "2020-11-29T14:03:17Z")

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For the chemistry- or cheminformatics-inclined among you, you may be interested in PubChemCrawler, which makes it easier to query the PubChem service. https://github.com/JuliaHealth/PubChemCrawler.jl

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## [What is the fastest way to parse a string of numbers into a tuple / struct with different field types?](https://discourse.julialang.org/t/what-is-the-fastest-way-to-parse-a-string-of-numbers-into-a-tuple-struct-with-different-field-types/50905)

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**Author:** [@Vasily\_Pisarev](https://discourse.julialang.org/u/Vasily_Pisarev)\
**Replies:** 5\
**Last updated:** [November 29, 2020, 1:51pm UTC](https://discourse.julialang.org/t/what-is-the-fastest-way-to-parse-a-string-of-numbers-into-a-tuple-struct-with-different-field-types/50905 "2020-11-29T13:51:52Z")

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Suppose I have a large table whose rows look like 3 1 2.5 4.0 10.1 and I know for sure that the first two columns are Ints and the next three are Float64s. Is there a way to use that information to write a fast parsin…

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## [VS Code cursor jumps to the end of file after execution](https://discourse.julialang.org/t/vs-code-cursor-jumps-to-the-end-of-file-after-execution/50929)

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**Author:** [@fedoroff](https://discourse.julialang.org/u/fedoroff)\
**Replies:** 2\
**Last updated:** [November 29, 2020, 11:29am UTC](https://discourse.julialang.org/t/vs-code-cursor-jumps-to-the-end-of-file-after-execution/50929 "2020-11-29T11:29:04Z")

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When I execute a file in VS Code by pressing “Shift+Enter” the cursor jumps to the end of the file. How can I avoid this behavior?

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## [Calling Julia functions (which take custom structs as inputs) from Python](https://discourse.julialang.org/t/calling-julia-functions-which-take-custom-structs-as-inputs-from-python/50567)

<div class="topic-metadata">

**Author:** [@apg](https://discourse.julialang.org/u/apg)\
**Replies:** 9\
**Last updated:** [November 29, 2020, 7:25am UTC](https://discourse.julialang.org/t/calling-julia-functions-which-take-custom-structs-as-inputs-from-python/50567 "2020-11-29T07:25:03Z")

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I’ve been trying to figure out a systematic way to call Julia functions from Python. I came across pyjulia library (in python) and PyCall modules (in julia) which seem to be pretty useful. However, most of the examples s…

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## [Unable to numerically differentiate in Calculus.jl Integers not Reals](https://discourse.julialang.org/t/unable-to-numerically-differentiate-in-calculus-jl-integers-not-reals/49211)

<div class="topic-metadata">

**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 19\
**Last updated:** [November 29, 2020, 3:55am UTC](https://discourse.julialang.org/t/unable-to-numerically-differentiate-in-calculus-jl-integers-not-reals/49211 "2020-11-29T03:55:57Z")

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using Calculs f(x) = sin(x) f'(1.0) - cos(1.0) When I run this, I get an error saying it doesn’t accept 64bit integers. How do I change the type of a function to a real number?

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## [Handling "cyclical" dependencies upon new release?](https://discourse.julialang.org/t/handling-cyclical-dependencies-upon-new-release/50910)

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**Author:** [@tpoisot](https://discourse.julialang.org/u/tpoisot)\
**Replies:** 1\
**Last updated:** [November 29, 2020, 2:40am UTC](https://discourse.julialang.org/t/handling-cyclical-dependencies-upon-new-release/50910 "2020-11-29T02:40:13Z")

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I have a package (A) that is in its 0.3 versions, and I am about to update it to 0.4. To generate the documentation, I use two other packages (B, C) that depend on A. For the moment, I cannot build the documentation of A …

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