# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=348

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**Page:** 349

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## [JuMP & SumOfSquares generate SDPs with ~18x more constraints than YALMIP](https://discourse.julialang.org/t/jump-sumofsquares-generate-sdps-with-18x-more-constraints-than-yalmip/65377)

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**Author:** [@ciba12](https://discourse.julialang.org/u/ciba12)\
**Replies:** 15\
**Last updated:** [July 30, 2021, 1:45pm UTC](https://discourse.julialang.org/t/jump-sumofsquares-generate-sdps-with-18x-more-constraints-than-yalmip/65377 "2021-07-30T13:45:13Z")

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Hi, I am attempting to rewrite MATLAB code, which is slow due to Yalmip’s parsing speed. The resulting problem that gets sent to the solver from JuMP is much larger (and slower to solve) than Yalmip’s output. I don’t t…

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## [Problem with Ntuple and VariableRef when using NLconstraint in JuMP](https://discourse.julialang.org/t/problem-with-ntuple-and-variableref-when-using-nlconstraint-in-jump/65200)

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**Author:** [@ylish](https://discourse.julialang.org/u/ylish)\
**Replies:** 4\
**Last updated:** [July 30, 2021, 11:27am UTC](https://discourse.julialang.org/t/problem-with-ntuple-and-variableref-when-using-nlconstraint-in-jump/65200 "2021-07-30T11:27:11Z")

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Hi everybody, Below is a simplified part of my code, which attempts to do nonlinear optimization using JuMP . I have both cost and constraints which require vector input. However I am having issues with NLconstraint. Wo…

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## [CUDA requirements](https://discourse.julialang.org/t/cuda-requirements/65355)

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**Author:** [@Philippe\_Maincon1](https://discourse.julialang.org/u/Philippe_Maincon1)\
**Replies:** 2\
**Last updated:** [July 30, 2021, 9:06am UTC](https://discourse.julialang.org/t/cuda-requirements/65355 "2021-07-30T09:06:50Z")

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First, thanks to Tim & co. for great JuliaCon workshops. I was not able to install CUDA.jl, unfortunately. My PC only has Intel UHD Graphics 620, no NVIDIA card. Am I right in assuming that CUDA.jl requires an NVIDIA …

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## [CUDA.jl - ERROR: LoadError: LoadError: UndefVarError: parameters not defined](https://discourse.julialang.org/t/cuda-jl-error-loaderror-loaderror-undefvarerror-parameters-not-defined/65501)

<div class="topic-metadata">

**Author:** [@molen89](https://discourse.julialang.org/u/molen89)\
**Replies:** 1\
**Last updated:** [July 30, 2021, 8:58am UTC](https://discourse.julialang.org/t/cuda-jl-error-loaderror-loaderror-undefvarerror-parameters-not-defined/65501 "2021-07-30T08:58:02Z")

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I am having issues with the cuda/flux packages when using the gpu. Example code using Flux, CUDA m = Dense(10,5) |\> gpu x = rand(10) |\> gpu m(x) \> UndefVarError: parameters not defined versions Julia 1.6.1 CUDA 11.…

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## [Plot 2D histogram of 3D+ multivariate data](https://discourse.julialang.org/t/plot-2d-histogram-of-3d-multivariate-data/65525)

<div class="topic-metadata">

**Author:** [@thompsonmj](https://discourse.julialang.org/u/thompsonmj)\
**Replies:** 1\
**Last updated:** [July 29, 2021, 10:02pm UTC](https://discourse.julialang.org/t/plot-2d-histogram-of-3d-multivariate-data/65525 "2021-07-29T22:02:09Z")

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To plot a bivariate histogram with as many bins as I like in each dimension, I can use using StatsBase, Plots d1 = randn(10\_000) d2 = randn(10\_000) nbins1 = 25 nbins2 = 10 hist = fit(Histogram, (d1,d2), (range(mini…

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## [How to remove overhead due to nested optimization with Optim package](https://discourse.julialang.org/t/how-to-remove-overhead-due-to-nested-optimization-with-optim-package/65439)

<div class="topic-metadata">

**Author:** [@Joris\_Pinkse](https://discourse.julialang.org/u/Joris_Pinkse)\
**Replies:** 7\
**Last updated:** [July 29, 2021, 7:36pm UTC](https://discourse.julialang.org/t/how-to-remove-overhead-due-to-nested-optimization-with-optim-package/65439 "2021-07-29T19:36:52Z")

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Consider minimizing f(x, y1, y2) using a nested procedure. In an inner loop y1, y2 are minimized as a function of x and in the outer loop f( x, y1(x), y2(x) ) is minimized where y1(x), y2(x) are the solutions to the inn…

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## [@formula for Lathe.preprocess UndefVarError](https://discourse.julialang.org/t/formula-for-lathe-preprocess-undefvarerror/65504)

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**Author:** [@YummyPampers2](https://discourse.julialang.org/u/YummyPampers2)\
**Replies:** 12\
**Last updated:** [July 29, 2021, 6:11pm UTC](https://discourse.julialang.org/t/formula-for-lathe-preprocess-undefvarerror/65504 "2021-07-29T18:11:48Z")

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Hello Everyone: I am attempting to perform a logistic regression and for some reason the @formula macro, is not reading. using GLM using Lathe: preprocess fm = @formula(Outcome ~ Sesh1 + Shes2 + Sesh3) logit = glm…

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## [Recent errors with WGLMakie on Pluto](https://discourse.julialang.org/t/recent-errors-with-wglmakie-on-pluto/64859)

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**Author:** [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Replies:** 18\
**Last updated:** [July 29, 2021, 11:54am UTC](https://discourse.julialang.org/t/recent-errors-with-wglmakie-on-pluto/64859 "2021-07-29T11:54:47Z")

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I don’t know what happened but I started getting this warning on a previously working Pluto notebook with WGLMakie plots: ┌ Warning: Waiting for page sessions to load. │ This can happen for the first cel…

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## [Getting started: MIP variables and datastructure](https://discourse.julialang.org/t/getting-started-mip-variables-and-datastructure/63766)

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**Author:** [@Annette\_F](https://discourse.julialang.org/u/Annette_F)\
**Replies:** 11\
**Last updated:** [July 29, 2021, 11:42am UTC](https://discourse.julialang.org/t/getting-started-mip-variables-and-datastructure/63766 "2021-07-29T11:42:33Z")

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Hi all, In short; I’m trying to find if and how I can formulate a MIP on a datastructure. I have a set of orders ( with handling time, start location, end location and each location a timewindow ) And I want to combin…

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## [\`num\_constraints\` to return the total number of constraints](https://discourse.julialang.org/t/num-constraints-to-return-the-total-number-of-constraints/65488)

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**Author:** [@raphaelsaavedra](https://discourse.julialang.org/u/raphaelsaavedra)\
**Replies:** 2\
**Last updated:** [July 29, 2021, 11:08am UTC](https://discourse.julialang.org/t/num-constraints-to-return-the-total-number-of-constraints/65488 "2021-07-29T11:08:37Z")

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Apparently num\_constraints only accepts concrete types, which means it’s not straightforward to return the total number of constraints in the model. Is there a straightforward way of doing this, or do we need to resort t…

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## [\[ANN\] ERFA.jl 1.0 (and 1.1) – Essential Routines for Fundamental Astronomy](https://discourse.julialang.org/t/ann-erfa-jl-1-0-and-1-1-essential-routines-for-fundamental-astronomy/65424)

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**Author:** [@helgee](https://discourse.julialang.org/u/helgee)\
**Replies:** 0\
**Last updated:** [July 28, 2021, 9:18am UTC](https://discourse.julialang.org/t/ann-erfa-jl-1-0-and-1-1-essential-routines-for-fundamental-astronomy/65424 "2021-07-28T09:18:21Z")

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The venerable ERFA.jl has reached version 1.0 :tada: For those who have not heard about it, yet, it is a Julia wrapper for liberfa which in turn is the open-source version of the Standards of Fundamental Astronomy (SOFA…

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## [CuArray supports bits type error when performing automatic differentiation in sciml\_train (possibly due to array reshaping)](https://discourse.julialang.org/t/cuarray-supports-bits-type-error-when-performing-automatic-differentiation-in-sciml-train-possibly-due-to-array-reshaping/65389)

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**Author:** [@timothypraditia](https://discourse.julialang.org/u/timothypraditia)\
**Replies:** 6\
**Last updated:** [July 28, 2021, 8:39pm UTC](https://discourse.julialang.org/t/cuarray-supports-bits-type-error-when-performing-automatic-differentiation-in-sciml-train-possibly-due-to-array-reshaping/65389 "2021-07-28T20:39:36Z")

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Hello everyone, I’m trying to convert my code so that it would run on GPU, but I still encountered some issues. My code is mainly using DiffEqFlux, with some array reshaping required inside the Neural ODE function itse…

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## [Lathe.jl: No Method Matching Error](https://discourse.julialang.org/t/lathe-jl-no-method-matching-error/65455)

<div class="topic-metadata">

**Author:** [@YummyPampers2](https://discourse.julialang.org/u/YummyPampers2)\
**Replies:** 0\
**Last updated:** [July 28, 2021, 6:41pm UTC](https://discourse.julialang.org/t/lathe-jl-no-method-matching-error/65455 "2021-07-28T18:41:48Z")

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Hello Everyone: I am using Lathe:preprocess Have attempted to activate the following functions from HERE: begin mutable struct OneHotEncoder{P} \<: Lathe.preprocess.Encoder predict::P function OneHotEncoder…

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## [Line thickness, marker size scales in Makie](https://discourse.julialang.org/t/line-thickness-marker-size-scales-in-makie/65447)

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**Author:** [@keithjlee](https://discourse.julialang.org/u/keithjlee)\
**Replies:** 0\
**Last updated:** [July 28, 2021, 4:17pm UTC](https://discourse.julialang.org/t/line-thickness-marker-size-scales-in-makie/65447 "2021-07-28T16:17:35Z")

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I’m currently trying to make sense of how Makie (GLMakie) deals with scaling of element sizes. I’m trying to make a quick function that visualizes structures for finite element analysis, just simple points and lines tha…

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## [Data-formatting in and out of Flux ML model](https://discourse.julialang.org/t/data-formatting-in-and-out-of-flux-ml-model/65383)

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**Author:** [@amit1](https://discourse.julialang.org/u/amit1)\
**Replies:** 1\
**Last updated:** [July 28, 2021, 4:15pm UTC](https://discourse.julialang.org/t/data-formatting-in-and-out-of-flux-ml-model/65383 "2021-07-28T16:15:29Z")

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Hi, I am still learning the ropes of Flux framework. I have experience of tensorflow and bit of pytorch, but I am interested in Flux, mostly because of the flexibility and uniformity (no more to\_numpy and vice versa!). I…

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## [Scaling for multi-threading](https://discourse.julialang.org/t/scaling-for-multi-threading/65301)

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**Author:** [@francispoulin](https://discourse.julialang.org/u/francispoulin)\
**Replies:** 10\
**Last updated:** [July 28, 2021, 4:14pm UTC](https://discourse.julialang.org/t/scaling-for-multi-threading/65301 "2021-07-28T16:14:35Z")

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A question for @luraess and @samo . In the mini-course you gave here you give a lot of different code to solve the diffusion equation in 3D, which was a lot of fun. I know that you have shown that multi-GPU can be effic…

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## [My ConstraintSolver.jl page](https://discourse.julialang.org/t/my-constraintsolver-jl-page/65430)

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**Author:** [@Hakan\_Kjellerstrand](https://discourse.julialang.org/u/Hakan_Kjellerstrand)\
**Replies:** 2\
**Last updated:** [July 28, 2021, 12:17pm UTC](https://discourse.julialang.org/t/my-constraintsolver-jl-page/65430 "2021-07-28T12:17:38Z")

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One of my (other) Julia-related interests is Ole Kröger’s Home · ConstraintSolver . My ConstraintSolver.jl models are here: My Julia ConstraintSolver.jl page , also available at https://github.com/hakank/hakank/tree/mas…

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## [Converting a Time() to an standardized Int64 or Float64](https://discourse.julialang.org/t/converting-a-time-to-an-standardized-int64-or-float64/65404)

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**Author:** [@YummyPampers2](https://discourse.julialang.org/u/YummyPampers2)\
**Replies:** 7\
**Last updated:** [July 28, 2021, 9:11am UTC](https://discourse.julialang.org/t/converting-a-time-to-an-standardized-int64-or-float64/65404 "2021-07-28T09:11:06Z")

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Hello Everyone: I instantiated a variable using Sprints = Time(00,01,00):Dates.Minute(1):Time(01,00,00) and created a data frame with: Allstars = DataFrame(Id = 1:10, BestTimes = rand(Sprints, 10)) How could I conve…

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## [Changing Gtk widget border/background colors](https://discourse.julialang.org/t/changing-gtk-widget-border-background-colors/5126)

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**Author:** [@jpsamaroo](https://discourse.julialang.org/u/jpsamaroo)\
**Replies:** 3\
**Last updated:** [July 28, 2021, 8:40am UTC](https://discourse.julialang.org/t/changing-gtk-widget-border-background-colors/5126 "2021-07-28T08:40:15Z")

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I’m having a bit of difficulty trying to understand how one would set the background or border color of a widget with Gtk.jl. I’ve taken a look at this issue, but haven’t been able to make it work with Julia 0.6 and Gtk …

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## [Precise control of navigation in 3D scene in Makie?](https://discourse.julialang.org/t/precise-control-of-navigation-in-3d-scene-in-makie/62387)

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**Author:** [@hacklint](https://discourse.julialang.org/u/hacklint)\
**Replies:** 7\
**Last updated:** [July 27, 2021, 11:27pm UTC](https://discourse.julialang.org/t/precise-control-of-navigation-in-3d-scene-in-makie/62387 "2021-07-27T23:27:56Z")

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Hi, I’m starting to visualize a collection of meshes in Makie, currently using the mouse to navigate the content. However, after a while the rotate, drag and zoom performed usually make me end up with parts of the conte…

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## [Styling AlgebraOfGraphics boxplots](https://discourse.julialang.org/t/styling-algebraofgraphics-boxplots/65335)

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**Author:** [@jbmuir](https://discourse.julialang.org/u/jbmuir)\
**Replies:** 13\
**Last updated:** [July 27, 2021, 10:30pm UTC](https://discourse.julialang.org/t/styling-algebraofgraphics-boxplots/65335 "2021-07-27T22:30:53Z")

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I’m amazed how easy it is to make complex and good-looking figures using AlgebraOfGraphics - it is still a little opaque as to how to use custom styles in them though. I’d like to be able to change the colors in this…

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## [Adding a linear or logistic equation to a curve plot](https://discourse.julialang.org/t/adding-a-linear-or-logistic-equation-to-a-curve-plot/65348)

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**Author:** [@YummyPampers2](https://discourse.julialang.org/u/YummyPampers2)\
**Replies:** 3\
**Last updated:** [July 27, 2021, 5:50pm UTC](https://discourse.julialang.org/t/adding-a-linear-or-logistic-equation-to-a-curve-plot/65348 "2021-07-27T17:50:03Z")

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Hello Everyone: Is there an approach to displaying the regression equation on a curve plot? I would like to avoid using PyCall.jl or SciKitLearn.jl. I am using StatsPlots.jl with a PlotlyJS backend(). Initially, I …

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## [Understanding MultiAgent in ReinforcementLearning.jl](https://discourse.julialang.org/t/understanding-multiagent-in-reinforcementlearning-jl/65269)

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**Author:** [@thae](https://discourse.julialang.org/u/thae)\
**Replies:** 2\
**Last updated:** [July 27, 2021, 2:04pm UTC](https://discourse.julialang.org/t/understanding-multiagent-in-reinforcementlearning-jl/65269 "2021-07-27T14:04:44Z")

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Hello, let it be known that I know little about Julia and even less about Reinforcement Learning. I’ve written an environment so trivial it is meaningless just to understand how everything fits together. It’s a four-pla…

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## [Need Diffractor.jl for State-of-the-Art Deep Learning Model](https://discourse.julialang.org/t/need-diffractor-jl-for-state-of-the-art-deep-learning-model/59423)

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**Author:** [@Freddy\_Chua](https://discourse.julialang.org/u/Freddy_Chua)\
**Replies:** 12\
**Last updated:** [July 27, 2021, 11:03am UTC](https://discourse.julialang.org/t/need-diffractor-jl-for-state-of-the-art-deep-learning-model/59423 "2021-07-27T11:03:15Z")

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Hi, I hope to beta test for your Diffractor.jl next generation AD. I am a co-author of DeepCPCFG \[2103.05908\] DeepCPCFG: Deep Learning and Context Free Grammars for End-to-End Information Extraction. This research is a…

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## [Unable to write DataFrame to Parquet or Arrow?](https://discourse.julialang.org/t/unable-to-write-dataframe-to-parquet-or-arrow/65284)

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**Author:** [@NowanIlfideme](https://discourse.julialang.org/u/NowanIlfideme)\
**Replies:** 7\
**Last updated:** [July 27, 2021, 9:07am UTC](https://discourse.julialang.org/t/unable-to-write-dataframe-to-parquet-or-arrow/65284 "2021-07-27T09:07:11Z")

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Hi, I’m trying to save a large DataFrame. Long story short, only the CSV and Feather packages seem to work at all, but I would prefer Arrow or Parquet. I’ve installed Parquet.jl and Arrow.jl, but they fail to work. I ass…

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## [My Turing.jl models](https://discourse.julialang.org/t/my-turing-jl-models/65258)

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**Author:** [@Hakan\_Kjellerstrand](https://discourse.julialang.org/u/Hakan_Kjellerstrand)\
**Replies:** 2\
**Last updated:** [July 26, 2021, 4:36pm UTC](https://discourse.julialang.org/t/my-turing-jl-models/65258 "2021-07-26T16:36:03Z")

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I have now finished porting most of my WebPPL and BLOG models to Turing.jl. They are collected at My Julia Turing.jl (probabilistic programming) page and also available at my GitHub page: https://github.com/hakank/hakank…

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## [CUDA.@cuStaticSharedMem returning a Structure of Arrays](https://discourse.julialang.org/t/cuda-custaticsharedmem-returning-a-structure-of-arrays/65307)

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**Author:** [@shiroghost](https://discourse.julialang.org/u/shiroghost)\
**Replies:** 0\
**Last updated:** [July 26, 2021, 2:13pm UTC](https://discourse.julialang.org/t/cuda-custaticsharedmem-returning-a-structure-of-arrays/65307 "2021-07-26T14:13:30Z")

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Working on the GPU I usually find convenient to use Structure of Arrays. I use GitHub - JuliaArrays/StructArrays.jl: Efficient implementation of struct arrays in Julia For example, I use: struct pt x::Float64 Y::Float6…

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## [Generic Affine Expression in a constraint](https://discourse.julialang.org/t/generic-affine-expression-in-a-constraint/65275)

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**Author:** [@Daniel\_Villamar](https://discourse.julialang.org/u/Daniel_Villamar)\
**Replies:** 1\
**Last updated:** [July 26, 2021, 9:00am UTC](https://discourse.julialang.org/t/generic-affine-expression-in-a-constraint/65275 "2021-07-26T09:00:34Z")

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I am having a hard time with a NL model that I am creating. My model uses matrices and therefore my variable and constraints are arrays. I want to create an array of constraints that includes some calculations with my v…

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## [About @connectors](https://discourse.julialang.org/t/about-connectors/65083)

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**Author:** [@juliascrub](https://discourse.julialang.org/u/juliascrub)\
**Replies:** 3\
**Last updated:** [July 26, 2021, 12:47am UTC](https://discourse.julialang.org/t/about-connectors/65083 "2021-07-26T00:47:08Z")

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Ive got a model defined as a connector @connector function Pin(iv::Num; name) ... end And another model composed of these connectors: function ModelWithConnectors(iv::Num; name) @named a = Pin(iv) @named b …

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## [Excel data to dataframes](https://discourse.julialang.org/t/excel-data-to-dataframes/65264)

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**Author:** [@mjanun](https://discourse.julialang.org/u/mjanun)\
**Replies:** 16\
**Last updated:** [July 25, 2021, 7:21pm UTC](https://discourse.julialang.org/t/excel-data-to-dataframes/65264 "2021-07-25T19:21:39Z")

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I have some data in different columns of an Excel sheet. I want to read the different columns into separate dataframes. I know the the column name/number where the data for each dataframe starts but not number of rows of…

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