# Latest

**URL:** https://discourse.julialang.org/latest.md?page=682

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

**Page:** 683

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## [About using powermodels to solve problems with SDP-OPF](https://discourse.julialang.org/t/about-using-powermodels-to-solve-problems-with-sdp-opf/99750)

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**Author:** [@lzq-zbc](https://discourse.julialang.org/u/lzq-zbc)\
**Replies:** 1\
**Last updated:** [June 2, 2023, 3:36am UTC](https://discourse.julialang.org/t/about-using-powermodels-to-solve-problems-with-sdp-opf/99750 "2023-06-02T03:36:35Z")

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I want to use the ECOS solver to solve some errors in the SDP model in OPF. using JuMP, PowerModels, Ipopt,ECOS file\_name = "E:/Vscode——data/data/case5.m" model = Model(ECOS.Optimizer) power\_model = PowerModels.instan…

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## [Watching new files being made in a folder?](https://discourse.julialang.org/t/watching-new-files-being-made-in-a-folder/86444)

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**Author:** [@Ahmed\_Salih](https://discourse.julialang.org/u/Ahmed_Salih)\
**Replies:** 2\
**Last updated:** [June 2, 2023, 3:32am UTC](https://discourse.julialang.org/t/watching-new-files-being-made-in-a-folder/86444 "2023-06-02T03:32:14Z")

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Hello! I have a case in which new files are being made in a directory every x seconds. My question is how do I use Filewatching.watch\_folder in such a way that is registers and prints to the terminal each newly made fi…

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## [Neumann series expander for solving linear problem?](https://discourse.julialang.org/t/neumann-series-expander-for-solving-linear-problem/99736)

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**Author:** [@ehgus](https://discourse.julialang.org/u/ehgus)\
**Replies:** 3\
**Last updated:** [June 2, 2023, 1:48am UTC](https://discourse.julialang.org/t/neumann-series-expander-for-solving-linear-problem/99736 "2023-06-02T01:48:49Z")

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Is there a package providing Neumann series expansion for solving linear problem? I usually solve Ax = b by calculating x = b + Sb + SSb + SSSb ... where S = 1- A, and I’d like to convert my matlab code into Julia. So …

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## [Is Julia's workflow like R's?](https://discourse.julialang.org/t/is-julias-workflow-like-rs/92529)

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**Author:** [@ForceBru](https://discourse.julialang.org/u/ForceBru)\
**Replies:** 20\
**Last updated:** [June 1, 2023, 11:55pm UTC](https://discourse.julialang.org/t/is-julias-workflow-like-rs/92529 "2023-06-01T23:55:26Z")

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So I frequently hear that Julia is supposed to be interactive, where you work mostly in the REPL: Julia’s REPL provides rich functionality that facilitates an efficient interactive workflow. The most basic Julia workf…

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## [How to navigate to end/start of current programming block with nvim-treesitter](https://discourse.julialang.org/t/how-to-navigate-to-end-start-of-current-programming-block-with-nvim-treesitter/99740)

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**Author:** [@filchristou](https://discourse.julialang.org/u/filchristou)\
**Replies:** 1\
**Last updated:** [June 1, 2023, 11:11pm UTC](https://discourse.julialang.org/t/how-to-navigate-to-end-start-of-current-programming-block-with-nvim-treesitter/99740 "2023-06-01T23:11:17Z")

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Have you found a way to go to the end/start of the current (where cursor is) most direct programming block (for-loop, if-else, let-block, struct, etc.) ? This is something that in julia-vim is implemented and supported …

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## [Julia exits when running several models (JuMP) in a row](https://discourse.julialang.org/t/julia-exits-when-running-several-models-jump-in-a-row/99686)

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**Author:** [@Yuri\_Masakazu\_Mizusa](https://discourse.julialang.org/u/Yuri_Masakazu_Mizusa)\
**Replies:** 6\
**Last updated:** [June 1, 2023, 11:08pm UTC](https://discourse.julialang.org/t/julia-exits-when-running-several-models-jump-in-a-row/99686 "2023-06-01T23:08:01Z")

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Hi, I’m running several instances on the same model in order to compare performance, like described below. My problem is that I have 1000 instances and halfway Julia exit, probably due to memory, but I don’t really und…

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## [Hard Disk storage solution for a (large) array of matrices](https://discourse.julialang.org/t/hard-disk-storage-solution-for-a-large-array-of-matrices/99734)

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**Author:** [@Mouad](https://discourse.julialang.org/u/Mouad)\
**Replies:** 12\
**Last updated:** [June 1, 2023, 9:33pm UTC](https://discourse.julialang.org/t/hard-disk-storage-solution-for-a-large-array-of-matrices/99734 "2023-06-01T21:33:02Z")

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I just finished an enormous scientific simulation (billions of regressions, trillions of allocations). The final output are a few arrays of matrices: 100000-element Vector{Matrix{Float64}}. I am looking for a solution t…

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## [\[ANN\] BlobTracking](https://discourse.julialang.org/t/ann-blobtracking/33291)

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**Author:** [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)\
**Replies:** 3\
**Last updated:** [June 1, 2023, 8:51pm UTC](https://discourse.julialang.org/t/ann-blobtracking/33291 "2023-06-01T20:51:11Z")

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I was searching around for packages or examples of blob tracking using Julia. To my surprise, I found nothing. Since I needed to do some blob tracking for the purpose of counting birds, I made a small package that can ho…

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## [Are you looking for a place to stay in Boston? Need a roommate?](https://discourse.julialang.org/t/are-you-looking-for-a-place-to-stay-in-boston-need-a-roommate/99741)

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**Author:** [@mkitti](https://discourse.julialang.org/u/mkitti)\
**Replies:** 0\
**Last updated:** [June 1, 2023, 7:57pm UTC](https://discourse.julialang.org/t/are-you-looking-for-a-place-to-stay-in-boston-need-a-roommate/99741 "2023-06-01T19:57:07Z")

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If you are still looking for a place to stay in Boston for JuliaCon 2023, feel free to post here. Use the accomodation, roommate, or invent a new tag as needed in this forum.

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## [Safely Analyzing Multiple Files with Multiple Threads](https://discourse.julialang.org/t/safely-analyzing-multiple-files-with-multiple-threads/99738)

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**Author:** [@gus-pendleton](https://discourse.julialang.org/u/gus-pendleton)\
**Replies:** 2\
**Last updated:** [June 1, 2023, 7:30pm UTC](https://discourse.julialang.org/t/safely-analyzing-multiple-files-with-multiple-threads/99738 "2023-06-01T19:30:43Z")

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Hello! I am writing functions which read multiple files of the same type, perform some analysis, and write results to a single object. I am unsure if the current way it is written is “safe” for multithreading. Here is a…

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## [BinaryBuilder specifying strict dependencies versions](https://discourse.julialang.org/t/binarybuilder-specifying-strict-dependencies-versions/99739)

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**Author:** [@vfonov](https://discourse.julialang.org/u/vfonov)\
**Replies:** 2\
**Last updated:** [June 1, 2023, 6:53pm UTC](https://discourse.julialang.org/t/binarybuilder-specifying-strict-dependencies-versions/99739 "2023-06-01T18:53:50Z")

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I have a small binary package, that I am building with BinaryBuilder, it links to HDF5 and NetCDF4. I would like to specify exact versions of these packages, currently I am using following code: ... Dependency(Package…

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## [Best way to find the last saved file in a folder?](https://discourse.julialang.org/t/best-way-to-find-the-last-saved-file-in-a-folder/99737)

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**Author:** [@phantom](https://discourse.julialang.org/u/phantom)\
**Replies:** 4\
**Last updated:** [June 1, 2023, 6:10pm UTC](https://discourse.julialang.org/t/best-way-to-find-the-last-saved-file-in-a-folder/99737 "2023-06-01T18:10:06Z")

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Hi! I have a folder where new files are constantly being added and I would like to know the best way to find the name of the last file saved. Thus far I am doing something like files = readdir(folder, join = true) las…

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## [Makie Alpha property in colormap is not observable. What's best way to mech this?](https://discourse.julialang.org/t/makie-alpha-property-in-colormap-is-not-observable-whats-best-way-to-mech-this/99731)

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**Author:** [@Allan\_Baker](https://discourse.julialang.org/u/Allan_Baker)\
**Replies:** 2\
**Last updated:** [June 1, 2023, 6:03pm UTC](https://discourse.julialang.org/t/makie-alpha-property-in-colormap-is-not-observable-whats-best-way-to-mech-this/99731 "2023-06-01T18:03:35Z")

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I have a function that makes a plot using lines/lines!. I can pass observables into the function and get the line x,y,z, and colormap value to update dynamically. The alpha value does not update as an observable. What…

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## [Precompiling module each time without any change](https://discourse.julialang.org/t/precompiling-module-each-time-without-any-change/99711)

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**Author:** [@peremato](https://discourse.julialang.org/u/peremato)\
**Replies:** 12\
**Last updated:** [June 1, 2023, 3:54pm UTC](https://discourse.julialang.org/t/precompiling-module-each-time-without-any-change/99711 "2023-06-01T15:54:42Z")

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Since I migrated to Julia 1.9 I get a pre-compilation of the module I am developing each time I start a test script. This was not the case with 1.8, for which I had sometimes to force a recompilation by modifying some of…

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## [ImageFiltering.jl](https://discourse.julialang.org/t/imagefiltering-jl/99721)

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**Author:** [@Ashwani\_Rathee](https://discourse.julialang.org/u/Ashwani_Rathee)\
**Replies:** 2\
**Last updated:** [June 1, 2023, 2:25pm UTC](https://discourse.julialang.org/t/imagefiltering-jl/99721 "2023-06-01T14:25:10Z")

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ImageFiltering.jl ImageFiltering.jl supports linear and nonlinear filtering operations on arrays, with an emphasis on the kinds of operations used in image processing. The core function is imfilter, and common kernels (f…

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## [Axis limits in 3D Makie plot](https://discourse.julialang.org/t/axis-limits-in-3d-makie-plot/99730)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 0\
**Last updated:** [June 1, 2023, 2:13pm UTC](https://discourse.julialang.org/t/axis-limits-in-3d-makie-plot/99730 "2023-06-01T14:13:50Z")

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How can I set the axis limits in this Makie code? using Distributions using Makie using WGLMakie N = 50 lat = rand(-20.:20., N) lon = rand(-180.:180., N) temp\_dist = Normal(85, 5) temp = rand(temp\_dist, N) dat…

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## [Disable SentinelArrays for CSV.read](https://discourse.julialang.org/t/disable-sentinelarrays-for-csv-read/54843)

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**Author:** [@robsmith11](https://discourse.julialang.org/u/robsmith11)\
**Replies:** 8\
**Last updated:** [June 1, 2023, 1:53pm UTC](https://discourse.julialang.org/t/disable-sentinelarrays-for-csv-read/54843 "2023-06-01T13:53:21Z")

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I’m reading a large CSV file of many Float64 values and then applying many possible transformations before doing a least squares fit. I noticed that the type is not plain Float64s despite there being no missing values: …

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## [Issue while using ReverseDiff in turing model](https://discourse.julialang.org/t/issue-while-using-reversediff-in-turing-model/99723)

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**Author:** [@Sahil\_Khan](https://discourse.julialang.org/u/Sahil_Khan)\
**Replies:** 4\
**Last updated:** [June 1, 2023, 1:16pm UTC](https://discourse.julialang.org/t/issue-while-using-reversediff-in-turing-model/99723 "2023-06-01T13:16:39Z")

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Hello, In discourse I found out that using reversediff is better for performance when you have high dimensional model. So, I’m trying to switch to reversediff from forwarddiff. But at the moment I’m facing this issue n…

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## [Speed up compilation with Zygote and PINN](https://discourse.julialang.org/t/speed-up-compilation-with-zygote-and-pinn/99652)

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**Author:** [@Matthieu\_BARREAU](https://discourse.julialang.org/u/Matthieu_BARREAU)\
**Replies:** 4\
**Last updated:** [June 1, 2023, 1:01pm UTC](https://discourse.julialang.org/t/speed-up-compilation-with-zygote-and-pinn/99652 "2023-06-01T13:01:23Z")

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Hi! I am relatively new to Julia and I am trying to move all my research projects to this new ecosystem instead of Python. However, I have trouble when my project deals with Physics informed neural network. Since I am …

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## [ForwardDiff.jl: Compute J\_f(x) \* f(x)](https://discourse.julialang.org/t/forwarddiff-jl-compute-j-f-x-f-x/99704)

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**Author:** [@ranocha](https://discourse.julialang.org/u/ranocha)\
**Replies:** 2\
**Last updated:** [June 1, 2023, 12:43pm UTC](https://discourse.julialang.org/t/forwarddiff-jl-compute-j-f-x-f-x/99704 "2023-06-01T12:43:15Z")

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There are some discussions how to compute the Jacobian-vector product J\_f(x) \* y for a function f efficiently with ForwardDiff.jl, e.g., Calculating J\_f(x) . y efficiently · Issue #319 · JuliaDiff/ForwardDiff.jl · GitHub …

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## [Getting return value From Function with loop](https://discourse.julialang.org/t/getting-return-value-from-function-with-loop/99714)

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**Author:** [@Stephen1959](https://discourse.julialang.org/u/Stephen1959)\
**Replies:** 7\
**Last updated:** [June 1, 2023, 12:20pm UTC](https://discourse.julialang.org/t/getting-return-value-from-function-with-loop/99714 "2023-06-01T12:20:21Z")

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Greetings. This ius my first post. Below is code that calculates the value of a scrabble word. It works well if I use the println() but cannot get it to return the value in total varable. Thanh you function score(st…

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## [Heatmap using categorical colours](https://discourse.julialang.org/t/heatmap-using-categorical-colours/99717)

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**Author:** [@pascal](https://discourse.julialang.org/u/pascal)\
**Replies:** 3\
**Last updated:** [June 1, 2023, 10:18am UTC](https://discourse.julialang.org/t/heatmap-using-categorical-colours/99717 "2023-06-01T10:18:37Z")

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I plot a heatmap of as using CairoMakie x=\[1; 2; 1; 2; 501; 500; 501; 500\] f = Figure() ax = Axis(f\[1,1\]) hm = heatmap!(ax, ones(8), 1:8, x, colormap=cgrad(:viridis, 4, categorical=true)) Colorbar(f\[:, 2\], hm) f Can I …

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## [LinearAlgebra.\* hangs when in a @threads loop on Apple M2 running 1.9.0 x86\_64](https://discourse.julialang.org/t/linearalgebra-hangs-when-in-a-threads-loop-on-apple-m2-running-1-9-0-x86-64/99630)

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**Author:** [@pitsianis](https://discourse.julialang.org/u/pitsianis)\
**Replies:** 6\
**Last updated:** [June 1, 2023, 7:21am UTC](https://discourse.julialang.org/t/linearalgebra-hangs-when-in-a-threads-loop-on-apple-m2-running-1-9-0-x86-64/99630 "2023-06-01T07:21:18Z")

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MacBook-Pro-M2 ~\> file /Applications/Julia-1.9.app/Contents/Resources/julia/bin/julia /Applications/Julia-1.9.app/Contents/Resources/julia/bin/julia: Mach-O 64-bit executable x86\_64 MacBook-Pro-M2 ~\> julia -t auto …

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## [Hanging in ijl\_gc\_collect() when using adopted threads](https://discourse.julialang.org/t/hanging-in-ijl-gc-collect-when-using-adopted-threads/99221)

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**Author:** [@peremato](https://discourse.julialang.org/u/peremato)\
**Replies:** 7\
**Last updated:** [June 1, 2023, 7:08am UTC](https://discourse.julialang.org/t/hanging-in-ijl-gc-collect-when-using-adopted-threads/99221 "2023-06-01T07:08:02Z")

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When using the MT mode of Geant4.jl the main thread hangs in an infinite loop in ijl\_gc\_collect(). I am using latest 1.9 version of Julia on MacOS. The way it works is as follows: The main thread (Julia REPL) calls C+…

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## [High-dimensional optimization problem with inequality constraint](https://discourse.julialang.org/t/high-dimensional-optimization-problem-with-inequality-constraint/63957)

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**Author:** [@mengxiaoliu](https://discourse.julialang.org/u/mengxiaoliu)\
**Replies:** 10\
**Last updated:** [June 1, 2023, 7:03am UTC](https://discourse.julialang.org/t/high-dimensional-optimization-problem-with-inequality-constraint/63957 "2023-06-01T07:03:33Z")

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Hello, I am solving a high-dimensional optimization problem with an inequality constraint using blackboxoptim. The objective function is differentiable, but I cannot write down the Hessians by hand. The dimensionality i…

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## [Flux runs out of memory](https://discourse.julialang.org/t/flux-runs-out-of-memory/73046)

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**Author:** [@sheevy](https://discourse.julialang.org/u/sheevy)\
**Replies:** 25\
**Last updated:** [June 1, 2023, 6:35am UTC](https://discourse.julialang.org/t/flux-runs-out-of-memory/73046 "2023-06-01T06:35:35Z")

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I’m running training conv net on 2000x2000 pixel image with Flux/Zygote on RTX 3070 (mobile) with 8GB of RAM and I’m getting out of memory exception when gradients are calculated: ERROR: LoadError: Out of GPU memory try…

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## ["bitwise and" vs "short-circuiting and", the dot version, which one should be used?](https://discourse.julialang.org/t/bitwise-and-vs-short-circuiting-and-the-dot-version-which-one-should-be-used/99211)

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**Author:** [@maxchendt](https://discourse.julialang.org/u/maxchendt)\
**Replies:** 9\
**Last updated:** [June 1, 2023, 3:08am UTC](https://discourse.julialang.org/t/bitwise-and-vs-short-circuiting-and-the-dot-version-which-one-should-be-used/99211 "2023-06-01T03:08:00Z")

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In Julia 1.9, both p .&& q and p .& q are working. But in 1.6.7 LTS, p .&& q is invalid p = \[true, true, false, false\] q = \[true, false, true, false\] #p .&& q #invalid syntax &q p .& q Should I ke…

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## [Telling Julia the type of a function's output (and other adventures in type stability)](https://discourse.julialang.org/t/telling-julia-the-type-of-a-functions-output-and-other-adventures-in-type-stability/99681)

<div class="topic-metadata">

**Author:** [@Bizzi](https://discourse.julialang.org/u/Bizzi)\
**Replies:** 5\
**Last updated:** [May 31, 2023, 8:23pm UTC](https://discourse.julialang.org/t/telling-julia-the-type-of-a-functions-output-and-other-adventures-in-type-stability/99681 "2023-05-31T20:23:07Z")

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Hey all. I’m having a bit of a hard time understanding types and how to deal with them. Take this small example involving Lux Networks: using Lux, Random, JET input = 1 n = 12 act = tanh model = Chain(Dense(input …

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## [JuliaCon 2023 talk acceptances are out!](https://discourse.julialang.org/t/juliacon-2023-talk-acceptances-are-out/95080)

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**Author:** [@logankilpatrick](https://discourse.julialang.org/u/logankilpatrick)\
**Replies:** 0\
**Last updated:** [February 23, 2023, 2:26pm UTC](https://discourse.julialang.org/t/juliacon-2023-talk-acceptances-are-out/95080 "2023-02-23T14:26:24Z")

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Hey folks, Thanks to all who submitted talks to JuliaCon 2023. It was a huge effort by the 100+ reviewers, @mfh, and @kslimes to make all of this happen but reviews and talk decisions are out. Please confirm your talks …

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## [JuliaCon 2023 Speakers please visit Pretalx and let us know your availibity](https://discourse.julialang.org/t/juliacon-2023-speakers-please-visit-pretalx-and-let-us-know-your-availibity/98182)

<div class="topic-metadata">

**Author:** [@Steven\_Kell](https://discourse.julialang.org/u/Steven_Kell)\
**Replies:** 0\
**Last updated:** [May 2, 2023, 12:32am UTC](https://discourse.julialang.org/t/juliacon-2023-speakers-please-visit-pretalx-and-let-us-know-your-availibity/98182 "2023-05-02T00:32:02Z")

</div>

You can visit Slack or message me if you need any help. Slack

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