# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1565

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

**Page:** 1566

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## [Strange CUDA\_ERROR\_OUT\_OF\_MEMORY when using CUDA on HPC](https://discourse.julialang.org/t/strange-cuda-error-out-of-memory-when-using-cuda-on-hpc/50428)

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**Author:** [@UtkarshChemE](https://discourse.julialang.org/u/UtkarshChemE)\
**Replies:** 5\
**Last updated:** [November 23, 2020, 6:45am UTC](https://discourse.julialang.org/t/strange-cuda-error-out-of-memory-when-using-cuda-on-hpc/50428 "2020-11-23T06:45:13Z")

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I am using CUDA.jl v2.3 on a HPC GPU cluster. There is a 50% chance that my job will receive an error of out of memory. Otherwise, the same script will run to completion. Any clue why this is happening. The error stack …

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## [Distributed.pgenerate not working as documented](https://discourse.julialang.org/t/distributed-pgenerate-not-working-as-documented/50615)

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**Author:** [@marius311](https://discourse.julialang.org/u/marius311)\
**Replies:** 0\
**Last updated:** [November 23, 2020, 6:28am UTC](https://discourse.julialang.org/t/distributed-pgenerate-not-working-as-documented/50615 "2020-11-23T06:28:04Z")

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The docstring for Distributed.pgenerate says Results are returned in order as they become available. which is exactly what I need. However, it doesn’t seem to be working this way, instead, the results are only return…

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## [Copying a QR decomposition matrix Q is extremely slow](https://discourse.julialang.org/t/copying-a-qr-decomposition-matrix-q-is-extremely-slow/50430)

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**Author:** [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Replies:** 7\
**Last updated:** [November 22, 2020, 8:58am UTC](https://discourse.julialang.org/t/copying-a-qr-decomposition-matrix-q-is-extremely-slow/50430 "2020-11-22T08:58:40Z")

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This is on julia 1.5.3 julia\> f = qr(ones(100, 20), Val(true)); julia\> copy(f.Q); @time copy(f.Q); 0.057310 seconds (40.00 k allocations: 338.516 MiB, 10.85% gc time) julia\> copy(Array(f.Q)); @time copy(Array(f.Q));…

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## [How did you get interested in programming?](https://discourse.julialang.org/t/how-did-you-get-interested-in-programming/46943)

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**Author:** [@anon60034542](https://discourse.julialang.org/u/anon60034542)\
**Replies:** 40\
**Last updated:** [November 23, 2020, 5:24am UTC](https://discourse.julialang.org/t/how-did-you-get-interested-in-programming/46943 "2020-11-23T05:24:20Z")

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After my last off topic question was so popular (ha!), I thought I might ask another question I saw a commercial the other day selling a product to teach coding at a younger age, and I was wondering how did you get inte…

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## [Support for CategoricalValue in StatsPlots](https://discourse.julialang.org/t/support-for-categoricalvalue-in-statsplots/47523)

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**Author:** [@skorpio11](https://discourse.julialang.org/u/skorpio11)\
**Replies:** 3\
**Last updated:** [November 23, 2020, 4:25am UTC](https://discourse.julialang.org/t/support-for-categoricalvalue-in-statsplots/47523 "2020-11-23T04:25:00Z")

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Hi I am following the walkthrough for StatsPlots at: https://github.com/JuliaPlots/StatsPlots.jl Using Julia Version 1.4.1 Got into problems when trying the violin plot: singers = RDatasets.dataset("lattice", "singer…

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## [Improving performance (Stochastic Path + Ipopt/Jump Optim on 32 cores/132RAM)](https://discourse.julialang.org/t/improving-performance-stochastic-path-ipopt-jump-optim-on-32-cores-132ram/50510)

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**Author:** [@Bruno](https://discourse.julialang.org/u/Bruno)\
**Replies:** 6\
**Last updated:** [November 23, 2020, 3:37am UTC](https://discourse.julialang.org/t/improving-performance-stochastic-path-ipopt-jump-optim-on-32-cores-132ram/50510 "2020-11-23T03:37:51Z")

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Hello! I’ve created a gist with some Julia code. Basically I generate a path of a stochastic process (size 1000 array) and use it to analytically estimate one of the parameters (via nonlinear optim on a max likelihood su…

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## [How to do technical analysis charts / visualizations using Julia?](https://discourse.julialang.org/t/how-to-do-technical-analysis-charts-visualizations-using-julia/40562)

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**Author:** [@MaxHayden](https://discourse.julialang.org/u/MaxHayden)\
**Replies:** 8\
**Last updated:** [November 22, 2020, 10:09pm UTC](https://discourse.julialang.org/t/how-to-do-technical-analysis-charts-visualizations-using-julia/40562 "2020-11-22T22:09:44Z")

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I am trying to improve my financial research workflow and need some help figuring out how to create some custom charts/visualizations. I don’t like my current mish-mash of C++, R, Python, and some proprietary charting p…

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## [CompatHelper, Travis balance depletion](https://discourse.julialang.org/t/compathelper-travis-balance-depletion/50604)

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**Author:** [@mkarikom](https://discourse.julialang.org/u/mkarikom)\
**Replies:** 0\
**Last updated:** [November 23, 2020, 12:58am UTC](https://discourse.julialang.org/t/compathelper-travis-balance-depletion/50604 "2020-11-23T00:58:18Z")

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Is CompatHelper somehow able to trigger Travis builds on one’s github projects and forks independent of one personally pushing commits to github? Only wondering because lately I’ve simultaneously noticed CompatHelper bl…

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## [Unusual JuMP and NLopt problem](https://discourse.julialang.org/t/unusual-jump-and-nlopt-problem/50595)

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**Author:** [@optimist](https://discourse.julialang.org/u/optimist)\
**Replies:** 4\
**Last updated:** [November 22, 2020, 11:59pm UTC](https://discourse.julialang.org/t/unusual-jump-and-nlopt-problem/50595 "2020-11-22T23:59:13Z")

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This is a rather unusual problem for JuMP as I am using it to find roots of a function. I have tried Optim and Roots packages but I find them frequently failing-most likely due to the way I use them! IntervalRootFinding …

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## [Function Composition vs Piping: Is there a performance difference?](https://discourse.julialang.org/t/function-composition-vs-piping-is-there-a-performance-difference/50589)

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**Author:** [@Obtuya7](https://discourse.julialang.org/u/Obtuya7)\
**Replies:** 4\
**Last updated:** [November 22, 2020, 9:11pm UTC](https://discourse.julialang.org/t/function-composition-vs-piping-is-there-a-performance-difference/50589 "2020-11-22T21:11:04Z")

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I noticed cases where the pipe operator (e.g. |\> ) is used over function composition (e.g. f(g(x))). I see composition used throughout the base code; so I assume that it’s the preferred convention. Are there any underly…

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## [Create variable name in dataframe that is groupby key](https://discourse.julialang.org/t/create-variable-name-in-dataframe-that-is-groupby-key/50590)

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**Author:** [@croberts](https://discourse.julialang.org/u/croberts)\
**Replies:** 1\
**Last updated:** [November 22, 2020, 8:07pm UTC](https://discourse.julialang.org/t/create-variable-name-in-dataframe-that-is-groupby-key/50590 "2020-11-22T20:07:31Z")

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Suppose we have the dataframe: df = DataFrame(Dict( :name =\> (“AAA”, “AAA”, “AAA”, “AAB”, “AAB”, “CCC”, “DDE”, “DDE”)) Each unique string in :name represents a group. We can use the split-apply-combine strategy descri…

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## [How do I install backends for Plots.jl](https://discourse.julialang.org/t/how-do-i-install-backends-for-plots-jl/50592)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 4\
**Last updated:** [November 22, 2020, 7:50pm UTC](https://discourse.julialang.org/t/how-do-i-install-backends-for-plots-jl/50592 "2020-11-22T19:50:17Z")

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How do I install a backend for Plots.jl? I wanted to try PGFPlotsX, to see if it would allow easier editing in LaTeX

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## [2 permanent academic positions in Engineering Maths, University of Bristol](https://discourse.julialang.org/t/2-permanent-academic-positions-in-engineering-maths-university-of-bristol/49993)

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**Author:** [@dawbarton](https://discourse.julialang.org/u/dawbarton)\
**Replies:** 4\
**Last updated:** [November 22, 2020, 4:13pm UTC](https://discourse.julialang.org/t/2-permanent-academic-positions-in-engineering-maths-university-of-bristol/49993 "2020-11-22T16:13:15Z")

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Not directly Julia related but I figure there are probably a fair few Julians interested in academic jobs, particularly around maths and data science — 2 permanent academic positions in Engineering Mathematics (Bristol,…

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## [Way to make SharedArray over fixed length Strings?](https://discourse.julialang.org/t/way-to-make-sharedarray-over-fixed-length-strings/7082)

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**Author:** [@djsegal](https://discourse.julialang.org/u/djsegal)\
**Replies:** 15\
**Last updated:** [November 22, 2020, 1:56pm UTC](https://discourse.julialang.org/t/way-to-make-sharedarray-over-fixed-length-strings/7082 "2020-11-22T13:56:20Z")

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if you do SharedArray{AbstractString}(10, 1) you get the following error: ERROR: ArgumentError: type of SharedArray elements must be bits types, got AbstractString Is there a package for making fixed length strings to…

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## [Sliders and plot together in one windows](https://discourse.julialang.org/t/sliders-and-plot-together-in-one-windows/50538)

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**Author:** [@Tomas\_Pevny](https://discourse.julialang.org/u/Tomas_Pevny)\
**Replies:** 2\
**Last updated:** [November 22, 2020, 1:16pm UTC](https://discourse.julialang.org/t/sliders-and-plot-together-in-one-windows/50538 "2020-11-22T13:16:01Z")

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Hi, I am preparing a lecture on Hypothesis testing for students and plan to go from the very basic, hopefully helping them understand the problems. Last year, my notebook was in Jupyter with Interact package, which was…

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## [How to add a function to show so that in a matrix latex is shown](https://discourse.julialang.org/t/how-to-add-a-function-to-show-so-that-in-a-matrix-latex-is-shown/50578)

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**Author:** [@Impressium](https://discourse.julialang.org/u/Impressium)\
**Replies:** 1\
**Last updated:** [November 22, 2020, 12:34pm UTC](https://discourse.julialang.org/t/how-to-add-a-function-to-show-so-that-in-a-matrix-latex-is-shown/50578 "2020-11-22T12:34:33Z")

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Hi dear community :slight\_smile: I created my own ModInt type and want to use it in a Matrix. I want to show it as rendered latex like: julia\> \[ModInt{5}(i+j) for i in 1:2, j in 1:2\] 2×2 Array{ModInt{5},2}: 2₅ 3₅ 3₅ …

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## [Fonts with consistent ligature support for Julia](https://discourse.julialang.org/t/fonts-with-consistent-ligature-support-for-julia/43584)

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**Author:** [@pauljurczak](https://discourse.julialang.org/u/pauljurczak)\
**Replies:** 14\
**Last updated:** [November 22, 2020, 11:05am UTC](https://discourse.julialang.org/t/fonts-with-consistent-ligature-support-for-julia/43584 "2020-11-22T11:05:18Z")

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I’ve used JetBrains Mono for coding before and I kept using it for Julia, but I’m not happy with some ligatures, especially the dot operator: There was a post mentioning the same issue with Fira Code (Fira Code Font a…

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## [Dual feasibility constraints, kkt conditions](https://discourse.julialang.org/t/dual-feasibility-constraints-kkt-conditions/50575)

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**Author:** [@AliRafieePour](https://discourse.julialang.org/u/AliRafieePour)\
**Replies:** 0\
**Last updated:** [November 22, 2020, 9:57am UTC](https://discourse.julialang.org/t/dual-feasibility-constraints-kkt-conditions/50575 "2020-11-22T09:57:16Z")

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Hi everyone, I’m quite new to Julia and was looking to automatically generate dual feasibility constraints, KKT conditions, strong duality constraints and add them to the initial primal problem for further steps. I have…

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## [Conversion to Gray{Bool}](https://discourse.julialang.org/t/conversion-to-gray-bool/50572)

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**Author:** [@Ashwani\_Rathee](https://discourse.julialang.org/u/Ashwani_Rathee)\
**Replies:** 1\
**Last updated:** [November 22, 2020, 8:24am UTC](https://discourse.julialang.org/t/conversion-to-gray-bool/50572 "2020-11-22T08:24:18Z")

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I wish to convert of type(which i loaded as a bitmap)(I tried other types before) Array{ColorTypes.RGB{FixedPointNumbers.Normed{UInt8,8}},2} to an object of type ColorTypes.Gray{Bool} I wanted to apply convex hull algo…

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## [Julia DifferentialEquations: add two delays into ODE](https://discourse.julialang.org/t/julia-differentialequations-add-two-delays-into-ode/50362)

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**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 14\
**Last updated:** [November 22, 2020, 8:13am UTC](https://discourse.julialang.org/t/julia-differentialequations-add-two-delays-into-ode/50362 "2020-11-22T08:13:14Z")

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Hello, I have a set of ODEs to model the invasion of a bacterium in presence of phages. I have inserted the invading bacterium at t=1000 using a delay. function multiInfect!(du, u, p, t) μ, ν, κ, φ, ψ, ω, β, Β, ρ, …

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## [Is there a Julia implementation of BUGS (Bayesian inference Using Gibbs Sampling)?](https://discourse.julialang.org/t/is-there-a-julia-implementation-of-bugs-bayesian-inference-using-gibbs-sampling/50564)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 1\
**Last updated:** [November 22, 2020, 6:07am UTC](https://discourse.julialang.org/t/is-there-a-julia-implementation-of-bugs-bayesian-inference-using-gibbs-sampling/50564 "2020-11-22T06:07:05Z")

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As the subject says. Any hints appreciated.

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## [Merge dataframes where one value is between two others](https://discourse.julialang.org/t/merge-dataframes-where-one-value-is-between-two-others/34738)

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**Author:** [@junder873](https://discourse.julialang.org/u/junder873)\
**Replies:** 7\
**Last updated:** [November 22, 2020, 4:24am UTC](https://discourse.julialang.org/t/merge-dataframes-where-one-value-is-between-two-others/34738 "2020-11-22T04:24:53Z")

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This question is very close to this Stackoverflow question. The primary issue is merging two dataframes with a restriction based on date ranges. This is a common issue in financial data, in my case, stock returns. The e…

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## [Speed up model in Turing](https://discourse.julialang.org/t/speed-up-model-in-turing/50555)

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**Author:** [@ohmsweetohm1](https://discourse.julialang.org/u/ohmsweetohm1)\
**Replies:** 1\
**Last updated:** [November 21, 2020, 10:46pm UTC](https://discourse.julialang.org/t/speed-up-model-in-turing/50555 "2020-11-21T22:46:30Z")

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Note that I am new to Turing as well as to Bayesian inference. I have to following simple Bayesian linear regression model. (This is pretty much the tutorial example) Turing.@model function linear\_regression(x, y) …

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## [Parallel version of code not giving the right answer](https://discourse.julialang.org/t/parallel-version-of-code-not-giving-the-right-answer/50553)

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**Author:** [@Rodrigue](https://discourse.julialang.org/u/Rodrigue)\
**Replies:** 2\
**Last updated:** [November 21, 2020, 10:08pm UTC](https://discourse.julialang.org/t/parallel-version-of-code-not-giving-the-right-answer/50553 "2020-11-21T22:08:44Z")

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I’m new to parallel computing (and Julia as well for that matter). I have a very simple code that works perfectly in the regular un-parallel set-up, but that doesn’t work when distributed across several workers. That is …

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## [Rules when box/unbox applies](https://discourse.julialang.org/t/rules-when-box-unbox-applies/50463)

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**Author:** [@JuergenD](https://discourse.julialang.org/u/JuergenD)\
**Replies:** 6\
**Last updated:** [November 21, 2020, 8:57pm UTC](https://discourse.julialang.org/t/rules-when-box-unbox-applies/50463 "2020-11-21T20:57:36Z")

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Aiming to be good citizen, I’ve followed PSA Make it easier to help you and prepared an, as much as possible, stripped down example Not sure if that matters, I’m on Win10 using Julia 1.5.3 abstract type AbstractField{T…

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## [Question about Franklin.jl](https://discourse.julialang.org/t/question-about-franklin-jl/50224)

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**Author:** [@adeil](https://discourse.julialang.org/u/adeil)\
**Replies:** 10\
**Last updated:** [November 21, 2020, 8:12pm UTC](https://discourse.julialang.org/t/question-about-franklin-jl/50224 "2020-11-21T20:12:43Z")

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I’m creating a website with Franklin.jl. However, after restarting my computer, the following message appears in the REPL when I try to modify the file: julia\> using Franklin julia\> serve() ┌ Franklin Warning: in \<conf…

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## [Promotion rules for custom structs](https://discourse.julialang.org/t/promotion-rules-for-custom-structs/50548)

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**Author:** [@cadojo](https://discourse.julialang.org/u/cadojo)\
**Replies:** 1\
**Last updated:** [November 21, 2020, 6:05pm UTC](https://discourse.julialang.org/t/promotion-rules-for-custom-structs/50548 "2020-11-21T18:05:24Z")

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I have a custom struct Body (shown below). For another struct, I’d like to be able to keep vectors of Body variables, and I’d like to be able to promote Body{Float32} to Body{Float64}, Body{Float64} to Body{BigFloat}, et…

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## [A mutable struct that does not get mutated ? or does it?](https://discourse.julialang.org/t/a-mutable-struct-that-does-not-get-mutated-or-does-it/50537)

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**Author:** [@lrnv](https://discourse.julialang.org/u/lrnv)\
**Replies:** 3\
**Last updated:** [November 21, 2020, 5:38pm UTC](https://discourse.julialang.org/t/a-mutable-struct-that-does-not-get-mutated-or-does-it/50537 "2020-11-21T17:38:21Z")

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Hi, I’m trying to code an extension do Distributions.jl for a certain distribution (Some gamma convolutions), and implementing the Moschopoulos algorithm. I have an issue: To compute the pdf, i need to cache certain va…

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## [Comparing type precision](https://discourse.julialang.org/t/comparing-type-precision/50540)

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**Author:** [@cadojo](https://discourse.julialang.org/u/cadojo)\
**Replies:** 1\
**Last updated:** [November 21, 2020, 5:06pm UTC](https://discourse.julialang.org/t/comparing-type-precision/50540 "2020-11-21T17:06:44Z")

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I’m building a struct that takes a collection of elements, and I want the inner constructor to parameterize the struct by the element type of the collection. I showed what I’m looking for as the max\_precision function i…

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## [CUDA.sqrt will not found symbol "\_\_nv\_sqrt"](https://discourse.julialang.org/t/cuda-sqrt-will-not-found-symbol-nv-sqrt/50533)

<div class="topic-metadata">

**Author:** [@HaoxuanGuo](https://discourse.julialang.org/u/HaoxuanGuo)\
**Replies:** 1\
**Last updated:** [November 21, 2020, 4:15pm UTC](https://discourse.julialang.org/t/cuda-sqrt-will-not-found-symbol-nv-sqrt/50533 "2020-11-21T16:15:55Z")

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I think this may be a bug and reported it. https://github.com/JuliaGPU/CUDA.jl/issues/559#issue-748013387 Now I wonder if this a artifact error because other math function like abs are not work too. But, what caused it…

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