# Latest

**URL:** https://discourse.julialang.org/latest.md?page=226

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

**Page:** 227

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## [Type instability and/or behavior instability of \`sqrt\` on nightly](https://discourse.julialang.org/t/type-instability-and-or-behavior-instability-of-sqrt-on-nightly/125428)

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**Author:** [@lkdvos](https://discourse.julialang.org/u/lkdvos)\
**Replies:** 3\
**Last updated:** [February 3, 2025, 8:20pm UTC](https://discourse.julialang.org/t/type-instability-and-or-behavior-instability-of-sqrt-on-nightly/125428 "2025-02-03T20:20:31Z")

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I noticed that since this commit for LinearAlgebra.jl, the default implementation of sqrt will now check if a matrix is diagonal to improve performance. There is however a change in behavior associated to this which mig…

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## [VSCode extension julia terminal not loading/adding \`LocalRegistry\` and private registries](https://discourse.julialang.org/t/vscode-extension-julia-terminal-not-loading-adding-localregistry-and-private-registries/125482)

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**Author:** [@00krishna](https://discourse.julialang.org/u/00krishna)\
**Replies:** 3\
**Last updated:** [February 3, 2025, 6:29pm UTC](https://discourse.julialang.org/t/vscode-extension-julia-terminal-not-loading-adding-localregistry-and-private-registries/125482 "2025-02-03T18:29:42Z")

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I had to rebuild my computer OS recently. I run ubuntu 22.04 LTS. I reinstalled julia and vscode, but for some reason I am having trouble with julia registries. So I use LocalRegistry for tracking development registries…

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## [I get errors when using module](https://discourse.julialang.org/t/i-get-errors-when-using-module/125351)

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**Author:** [@Fahim](https://discourse.julialang.org/u/Fahim)\
**Replies:** 3\
**Last updated:** [February 3, 2025, 4:24pm UTC](https://discourse.julialang.org/t/i-get-errors-when-using-module/125351 "2025-02-03T16:24:14Z")

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Dear Julia friends, First of all, I apologize for my poor English skills. I have a problem developing a module that uses Embeddings.jl: module Portal include("./t.jl") export get\_embedding end # module Portal using Em…

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## [Multi-thread speed in very large vectors](https://discourse.julialang.org/t/multi-thread-speed-in-very-large-vectors/125342)

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**Author:** [@pjssilva](https://discourse.julialang.org/u/pjssilva)\
**Replies:** 11\
**Last updated:** [February 3, 2025, 3:02pm UTC](https://discourse.julialang.org/t/multi-thread-speed-in-very-large-vectors/125342 "2025-02-03T15:02:26Z")

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Hi, I am trying to get my toes wet on some multi-threading code using the great OhMyThreads package. But there is a behavior that I don’t understand. I can exemplify it using the sum function. The most natural implementa…

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## [Approximate implicit function on real line](https://discourse.julialang.org/t/approximate-implicit-function-on-real-line/125421)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 7\
**Last updated:** [February 3, 2025, 2:31pm UTC](https://discourse.julialang.org/t/approximate-implicit-function-on-real-line/125421 "2025-02-03T14:31:38Z")

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I have a family of functions y(x) defined implicitly by x = \\log\\left(\\sum\_{i=1}^N \\exp(a\_i + y b\_i) \\right) where 0 \< b\_1 \< \\dots \< b\_N can be assumed. It is easy to find the solution numerically (eg with Newton’s m…

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## [Restrictions when adding a binary variable - Local Infeasibility (Ipopt, Juniper)](https://discourse.julialang.org/t/restrictions-when-adding-a-binary-variable-local-infeasibility-ipopt-juniper/121870)

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**Author:** [@fynnhoffmann54](https://discourse.julialang.org/u/fynnhoffmann54)\
**Replies:** 15\
**Last updated:** [January 23, 2025, 8:27am UTC](https://discourse.julialang.org/t/restrictions-when-adding-a-binary-variable-local-infeasibility-ipopt-juniper/121870 "2025-01-23T08:27:21Z")

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Hello, I am trying to model a nonlinear optimization problem involving binary variables and continuous variables. Specifically, I cannot understand why a binary variable “z\_sys\_to\_HP(s)” makes the model unusable. My mo…

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## [Change of behavior with \`hasmethod(eval(Meta.parse()))\`](https://discourse.julialang.org/t/change-of-behavior-with-hasmethod-eval-meta-parse/125500)

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**Author:** [@christophe.berthod](https://discourse.julialang.org/u/christophe.berthod)\
**Replies:** 3\
**Last updated:** [February 3, 2025, 2:05pm UTC](https://discourse.julialang.org/t/change-of-behavior-with-hasmethod-eval-meta-parse/125500 "2025-02-03T14:05:16Z")

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One of my codes broke due to a change of behavior of hasmethod(eval(Meta.parse())) around version 1.10.4. Prior to version 1.10.4 (e.g. 1.9.3) julia\> hasmethod(eval(Meta.parse("x-\>x")), (Real, )) true julia\> f(s) = ha…

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## [ModelingToolkit connector error with Arrays](https://discourse.julialang.org/t/modelingtoolkit-connector-error-with-arrays/123565)

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**Author:** [@fracpl](https://discourse.julialang.org/u/fracpl)\
**Replies:** 9\
**Last updated:** [February 3, 2025, 11:22am UTC](https://discourse.julialang.org/t/modelingtoolkit-connector-error-with-arrays/123565 "2025-02-03T11:22:08Z")

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Hi, I am trying to implement from scratch some 3D multibody dynamics with ModelingToolkit.jl. When I define my connector (Frame) using arrays: using ModelingToolkit using LinearAlgebra using ModelingToolkit: t\_nounits a…

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## [Tests fail on CI, pass locally](https://discourse.julialang.org/t/tests-fail-on-ci-pass-locally/125140)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 14\
**Last updated:** [January 31, 2025, 3:32pm UTC](https://discourse.julialang.org/t/tests-fail-on-ci-pass-locally/125140 "2025-01-31T15:32:22Z")

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The tests for the following pull requests pass locally, but fail on Github when using Julia 1.11 : Kcu steering · ufechner7/KiteModels.jl@5cd060d · GitHub Any idea how to debug that? The problem is that when running th…

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## [How to Use Native FP4 and FP8 for Computation in the Julia Environment with CUDA.jl](https://discourse.julialang.org/t/how-to-use-native-fp4-and-fp8-for-computation-in-the-julia-environment-with-cuda-jl/125475)

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**Author:** [@ajsagit](https://discourse.julialang.org/u/ajsagit)\
**Replies:** 0\
**Last updated:** [February 2, 2025, 3:15pm UTC](https://discourse.julialang.org/t/how-to-use-native-fp4-and-fp8-for-computation-in-the-julia-environment-with-cuda-jl/125475 "2025-02-02T15:15:47Z")

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How to Use Native FP4 and FP8 for Computation in the Julia Environment with CUDA.jl TIA

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## [Help with CUDA and Flux. DeviceMemory issue](https://discourse.julialang.org/t/help-with-cuda-and-flux-devicememory-issue/125481)

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**Author:** [@jcbritobr](https://discourse.julialang.org/u/jcbritobr)\
**Replies:** 2\
**Last updated:** [February 2, 2025, 11:17pm UTC](https://discourse.julialang.org/t/help-with-cuda-and-flux-devicememory-issue/125481 "2025-02-02T23:17:44Z")

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Hello, good evening. Im having an issue trying to run the Flux get started example. Always got ArgumentError: Illegal conversion of a CUDA.DeviceMemory to a Ptr{Float32} It brokes in line 17: out1 = model(nois…

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## [Most recent binary artifact (GMT\_jll) is not being updated, nor installed on fresh installs of GMT.jl](https://discourse.julialang.org/t/most-recent-binary-artifact-gmt-jll-is-not-being-updated-nor-installed-on-fresh-installs-of-gmt-jl/125473)

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**Author:** [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Replies:** 6\
**Last updated:** [February 2, 2025, 9:34pm UTC](https://discourse.julialang.org/t/most-recent-binary-artifact-gmt-jll-is-not-being-updated-nor-installed-on-fresh-installs-of-gmt-jl/125473 "2025-02-02T21:34:43Z")

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Hi, Don’t know what is happening but the new builds of the GMT\_jll artifact are not being installed. The artifact, 6.5.3+1, was created fine (GitHub - JuliaBinaryWrappers/GMT\_jll.jl at GMT-v6.5.3+1) but what keeps being…

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## [UndefVarError when using @turbo on nested for loop whose inner loop depends on value in outer loop](https://discourse.julialang.org/t/undefvarerror-when-using-turbo-on-nested-for-loop-whose-inner-loop-depends-on-value-in-outer-loop/125477)

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**Author:** [@leespen1](https://discourse.julialang.org/u/leespen1)\
**Replies:** 2\
**Last updated:** [February 2, 2025, 8:57pm UTC](https://discourse.julialang.org/t/undefvarerror-when-using-turbo-on-nested-for-loop-whose-inner-loop-depends-on-value-in-outer-loop/125477 "2025-02-02T20:57:54Z")

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I am trying to optimize some for-loops in a package I am working on, so I decided to check out LoopVectorization. I ran into some errors, and constructed the following MWE: using LoopVectorization function f(jmax,kmax)…

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## [What is the best way to get a running matrix-product over a large 3D array](https://discourse.julialang.org/t/what-is-the-best-way-to-get-a-running-matrix-product-over-a-large-3d-array/125452)

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**Author:** [@SanAlphaTau](https://discourse.julialang.org/u/SanAlphaTau)\
**Replies:** 9\
**Last updated:** [February 2, 2025, 4:44pm UTC](https://discourse.julialang.org/t/what-is-the-best-way-to-get-a-running-matrix-product-over-a-large-3d-array/125452 "2025-02-02T16:44:16Z")

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Heya, I am doing some markov process simulations which output NxN matrices these are stored (currently) in a 3D array X\[N, N, M) where M can be very large (1E6 or more). My code currently uses a reduce statement reduce…

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## [Why the Floating-Point Calculation Efficiency of CUDA.jl Does Not Reach the Official Theoretical Value](https://discourse.julialang.org/t/why-the-floating-point-calculation-efficiency-of-cuda-jl-does-not-reach-the-official-theoretical-value/125474)

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**Author:** [@ajsagit](https://discourse.julialang.org/u/ajsagit)\
**Replies:** 1\
**Last updated:** [February 2, 2025, 3:55pm UTC](https://discourse.julialang.org/t/why-the-floating-point-calculation-efficiency-of-cuda-jl-does-not-reach-the-official-theoretical-value/125474 "2025-02-02T15:55:10Z")

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using CUDA using BenchmarkTools using Printf function benchmark\_floating\_point(T::Type, size=2048) aligned\_size = div(size, 8) \* 8 A = CUDA.rand(T, (aligned\_size, aligned\_size)) B = CUDA.rand(T, (aligned\_siz…

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## [If in === ∈, why does .∈ work but .in fails with a ParseError?](https://discourse.julialang.org/t/if-in-why-does-work-but-in-fails-with-a-parseerror/125464)

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**Author:** [@Matheus](https://discourse.julialang.org/u/Matheus)\
**Replies:** 5\
**Last updated:** [February 2, 2025, 1:02pm UTC](https://discourse.julialang.org/t/if-in-why-does-work-but-in-fails-with-a-parseerror/125464 "2025-02-02T13:02:59Z")

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Hello everyone, I’m trying to understand the following behavior regarding in and ∈ (I guess they’re called operators?). While they are functionally identical (in === ∈ returns true), they behave differently when used wi…

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## [Nullspace in exact arithmetics](https://discourse.julialang.org/t/nullspace-in-exact-arithmetics/125471)

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**Author:** [@azoviktor](https://discourse.julialang.org/u/azoviktor)\
**Replies:** 4\
**Last updated:** [February 2, 2025, 1:03pm UTC](https://discourse.julialang.org/t/nullspace-in-exact-arithmetics/125471 "2025-02-02T13:03:19Z")

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Is there a generic Julia implementation of a nullspace in exact arithmetics? I.e., I am interested in nullspace(A::AbstractMatrix{T}), where T is any field number datatype. The return type of the method would be again Ab…

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## [Reading exact value of a pixel in an indexed (colormap) image](https://discourse.julialang.org/t/reading-exact-value-of-a-pixel-in-an-indexed-colormap-image/125467)

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**Author:** [@dgagnon](https://discourse.julialang.org/u/dgagnon)\
**Replies:** 2\
**Last updated:** [February 2, 2025, 11:31am UTC](https://discourse.julialang.org/t/reading-exact-value-of-a-pixel-in-an-indexed-colormap-image/125467 "2025-02-02T11:31:54Z")

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Hello I have a tiff file with pixel values in one byte and a color table. When I read the file I can display the RGB value of any pixel but want I want is the exact value of the pixel. This is a classified image and I d…

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## [Writing points to vtk with WriteVTK.jl](https://discourse.julialang.org/t/writing-points-to-vtk-with-writevtk-jl/50635)

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**Author:** [@O\_Julia](https://discourse.julialang.org/u/O_Julia)\
**Replies:** 3\
**Last updated:** [February 2, 2025, 10:22am UTC](https://discourse.julialang.org/t/writing-points-to-vtk-with-writevtk-jl/50635 "2025-02-02T10:22:47Z")

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Hi, I am trying to export a set of points with corresponding value at each point using WriteVTK.jl. More precisely, I am trying to convert following codes given here. from evtk.hl import pointsToVTK import numpy as n…

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## [Strange outcome for the Julia list with different type of elements](https://discourse.julialang.org/t/strange-outcome-for-the-julia-list-with-different-type-of-elements/125409)

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**Author:** [@miniskar](https://discourse.julialang.org/u/miniskar)\
**Replies:** 5\
**Last updated:** [February 2, 2025, 5:29am UTC](https://discourse.julialang.org/t/strange-outcome-for-the-julia-list-with-different-type-of-elements/125409 "2025-02-02T05:29:27Z")

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Here is the minimum working example. julia\> f= rand(Float32, 8) 8-element Vector{Float32}: 0.31442094 0.31442094 0.2593087 0.2593087 0.11091578 0.11091578 0.14340413 0.14340413 julia\> i = rand(Int32, 8) 8-eleme…

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## [Unclear allocation behaviour with built-in sum()](https://discourse.julialang.org/t/unclear-allocation-behaviour-with-built-in-sum/125304)

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**Author:** [@Deceneu](https://discourse.julialang.org/u/Deceneu)\
**Replies:** 4\
**Last updated:** [February 2, 2025, 1:04am UTC](https://discourse.julialang.org/t/unclear-allocation-behaviour-with-built-in-sum/125304 "2025-02-02T01:04:34Z")

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Hello, Introduction I’ve been trying to process some data and I’ve encountered crippling allocation when using the built-in sum(). I have some mid-level understanding of how to increase performance in Julia, but regardi…

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## [\`Zygote.gradient\` is 54000 TIMES slower than \`jax.gradient\`](https://discourse.julialang.org/t/zygote-gradient-is-54000-times-slower-than-jax-gradient/125396)

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**Author:** [@ForceBru](https://discourse.julialang.org/u/ForceBru)\
**Replies:** 80\
**Last updated:** [February 1, 2025, 9:25pm UTC](https://discourse.julialang.org/t/zygote-gradient-is-54000-times-slower-than-jax-gradient/125396 "2025-02-01T21:25:46Z")

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I’m almost unable to compute ant gradients (EDIT 9 hrs later: meant to say “any gradients”, but got gradients for ants) in Zygote. I initially attempted to optimize my model using around a million parameters, but it got …

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## [Can I manage the memory by myself?](https://discourse.julialang.org/t/can-i-manage-the-memory-by-myself/97250)

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**Author:** [@zhijie\_sun](https://discourse.julialang.org/u/zhijie_sun)\
**Replies:** 16\
**Last updated:** [February 1, 2025, 7:03pm UTC](https://discourse.julialang.org/t/can-i-manage-the-memory-by-myself/97250 "2025-02-01T19:03:19Z")

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I have a code, the GC live and RSS memory increased quickly when running, while I don’t need such big memory to do basic computation. I need to allocate lots of small dict for intermidiate computing before, and the memor…

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## [Segmentation Fault using packages](https://discourse.julialang.org/t/segmentation-fault-using-packages/125458)

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**Author:** [@kurt](https://discourse.julialang.org/u/kurt)\
**Replies:** 2\
**Last updated:** [February 1, 2025, 7:45pm UTC](https://discourse.julialang.org/t/segmentation-fault-using-packages/125458 "2025-02-01T19:45:03Z")

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Help! Every time i try using Julia’s package help in the REPL, i.e. “\]”, i get a segmentation error, and julia quits. Here is the output from versioninfo(): Julia Version 1.11.3 Commit d63adeda50d (2025-01-21 19:42 UTC…

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## [Creating Parametric ReLU in Flux](https://discourse.julialang.org/t/creating-parametric-relu-in-flux/10987)

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**Author:** [@Azamat](https://discourse.julialang.org/u/Azamat)\
**Replies:** 8\
**Last updated:** [February 1, 2025, 6:19pm UTC](https://discourse.julialang.org/t/creating-parametric-relu-in-flux/10987 "2025-02-01T18:19:48Z")

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I would like to create Parametric ReLU (PReLU), an activation function, that is described in \[1502.01852\] Delving Deep into Rectifiers: Surpassing Human-Level Performance on ImageNet Classification I know I should use u…

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## [Removing bounds checking for HPC - \`--check-bounds=unsafe\`?](https://discourse.julialang.org/t/removing-bounds-checking-for-hpc-check-bounds-unsafe/124897)

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**Author:** [@johnomotani](https://discourse.julialang.org/u/johnomotani)\
**Replies:** 51\
**Last updated:** [February 1, 2025, 4:05pm UTC](https://discourse.julialang.org/t/removing-bounds-checking-for-hpc-check-bounds-unsafe/124897 "2025-02-01T16:05:26Z")

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One of Julia’s main purposes is to enable high-performance computing at scale - it’s on the front page (Ecosystem → Parallel Computing at The Julia Programming Language)! However, apparently --check-bounds=no is becoming…

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## [How to develop code in Vulkan using Julia?](https://discourse.julialang.org/t/how-to-develop-code-in-vulkan-using-julia/125456)

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**Author:** [@mj2984](https://discourse.julialang.org/u/mj2984)\
**Replies:** 1\
**Last updated:** [February 1, 2025, 2:33pm UTC](https://discourse.julialang.org/t/how-to-develop-code-in-vulkan-using-julia/125456 "2025-02-01T14:33:52Z")

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I am looking to see if it is possible to generate SPIR-V code from Julia that can be used in Vulkan (Compute). Or something that can transform Julia code to Vulkan for compute purposes. The intention is to write a code …

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## [How to use size type as lower precision in Static Arrays?](https://discourse.julialang.org/t/how-to-use-size-type-as-lower-precision-in-static-arrays/125457)

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**Author:** [@mj2984](https://discourse.julialang.org/u/mj2984)\
**Replies:** 1\
**Last updated:** [February 1, 2025, 2:24pm UTC](https://discourse.julialang.org/t/how-to-use-size-type-as-lower-precision-in-static-arrays/125457 "2025-02-01T14:24:52Z")

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Currently Static Arrays throws an error if the size type is anything other than Int64. Considering the size of Arrays is much smaller, is it possible to support other types such as UInt8, Int8, etc?

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## [Only Abstract Types in Method Signatures](https://discourse.julialang.org/t/only-abstract-types-in-method-signatures/125435)

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**Author:** [@PatrickHaecker](https://discourse.julialang.org/u/PatrickHaecker)\
**Replies:** 6\
**Last updated:** [February 1, 2025, 11:23am UTC](https://discourse.julialang.org/t/only-abstract-types-in-method-signatures/125435 "2025-02-01T11:23:30Z")

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Reading @JonasWickman’s comment that views generally use abstract types for their method definition made me think. If the method has at least one type in its signature this type needs to have an abstract parent and if An…

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## [3D volume plot is blank with Plots.jl + GR.jl](https://discourse.julialang.org/t/3d-volume-plot-is-blank-with-plots-jl-gr-jl/125444)

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**Author:** [@photor](https://discourse.julialang.org/u/photor)\
**Replies:** 1\
**Last updated:** [February 1, 2025, 9:16am UTC](https://discourse.julialang.org/t/3d-volume-plot-is-blank-with-plots-jl-gr-jl/125444 "2025-02-01T09:16:13Z")

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The backend is GR. Thanks. julia\> using Plots julia\> heatmap(rand(10,10,10)) julia\> versioninfo() Julia Version 1.10.8 Commit 4c16ff44be (2025-01-22 10:06 UTC) Build Info: Official https://julialang.org/ release Pla…

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