# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?page=481

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**Page:** 482

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## [Automatically cropping images](https://discourse.julialang.org/t/automatically-cropping-images/29235)

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**Author:** [@merckxiaan](https://discourse.julialang.org/u/merckxiaan)\
**Replies:** 6\
**Last updated:** [September 27, 2019, 3:45pm UTC](https://discourse.julialang.org/t/automatically-cropping-images/29235 "2019-09-27T15:45:58Z")

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Hello, I’ve got a directory filled with a couple of hundred images, similar to something like this: The problem is a lot of these images aren’t centered or don’t take up a lot of the space (e.g. a lot of excess whitesp…

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## [Conditional if else constraint in JuMP](https://discourse.julialang.org/t/conditional-if-else-constraint-in-jump/29177)

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**Author:** [@gopal2017](https://discourse.julialang.org/u/gopal2017)\
**Replies:** 2\
**Last updated:** [September 27, 2019, 11:13am UTC](https://discourse.julialang.org/t/conditional-if-else-constraint-in-jump/29177 "2019-09-27T11:13:35Z")

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Hi, I want to use conditional if else in JuMP. I have seen ConditionalJuMP at https://juliaobserver.com/packages/ConditionalJuMP. But it won’t work for julia v0.5.2 Please mention any package for indicator constraints. …

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## [Simple custom recurrent layer in Flux](https://discourse.julialang.org/t/simple-custom-recurrent-layer-in-flux/26740)

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**Author:** [@Rassibassi](https://discourse.julialang.org/u/Rassibassi)\
**Replies:** 2\
**Last updated:** [September 27, 2019, 10:45am UTC](https://discourse.julialang.org/t/simple-custom-recurrent-layer-in-flux/26740 "2019-09-27T10:45:36Z")

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Hi, I am looking into Flux and trying to understand the recurrent functionality. The following code defines a first order low pass filter with Flux.Recur. using Flux using Flux.Tracker c = 0.5 function LP(h, x) h…

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## [Heatmap with labels per block](https://discourse.julialang.org/t/heatmap-with-labels-per-block/29152)

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**Author:** [@feanor12](https://discourse.julialang.org/u/feanor12)\
**Replies:** 4\
**Last updated:** [September 25, 2019, 6:33pm UTC](https://discourse.julialang.org/t/heatmap-with-labels-per-block/29152 "2019-09-25T18:33:58Z")

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Is it possible to generate something like this (Create heatmap chart - MATLAB heatmap) with Plots.jl? Especially the labels inside the blocks. I could only find this example: http://docs.juliaplots.org/latest/examples/g…

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## [Uncertainty quantification of inverse problem using hierarchical Bayes: high-level modelling](https://discourse.julialang.org/t/uncertainty-quantification-of-inverse-problem-using-hierarchical-bayes-high-level-modelling/28681)

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**Author:** [@Oliver\_Lylloff](https://discourse.julialang.org/u/Oliver_Lylloff)\
**Replies:** 12\
**Last updated:** [September 25, 2019, 12:11pm UTC](https://discourse.julialang.org/t/uncertainty-quantification-of-inverse-problem-using-hierarchical-bayes-high-level-modelling/28681 "2019-09-25T12:11:50Z")

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Hi all, I’m trying to solve an example problem from a paper \[1\] and wish to do it with high-level modelling. I’m looking into Turing.jl but other packages may exist that I do not know of. For a didactic purpose I want t…

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## [Gridstudio supports Julia](https://discourse.julialang.org/t/gridstudio-supports-julia/29143)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 0\
**Last updated:** [September 25, 2019, 3:37am UTC](https://discourse.julialang.org/t/gridstudio-supports-julia/29143 "2019-09-25T03:37:35Z")

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https://gridstudio.io/announcement/ Does anyone know about gridstudio? It’s like an online Excel designed for data science.

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## [Gillespie in parallel on the GPU with DiffEqGPU?](https://discourse.julialang.org/t/gillespie-in-parallel-on-the-gpu-with-diffeqgpu/29114)

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**Author:** [@nilsbecker](https://discourse.julialang.org/u/nilsbecker)\
**Replies:** 1\
**Last updated:** [September 24, 2019, 2:44pm UTC](https://discourse.julialang.org/t/gillespie-in-parallel-on-the-gpu-with-diffeqgpu/29114 "2019-09-24T14:44:12Z")

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DifferentialEquations is getting support for integrating ODE parameters ensembles on the GPU, in parallel. Another example for an ‘embarassingly parallel’ problem is stochastic simulation with multiple copies of random n…

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## [Export trained model to PMML](https://discourse.julialang.org/t/export-trained-model-to-pmml/29110)

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**Author:** [@Carlos\_Roig](https://discourse.julialang.org/u/Carlos_Roig)\
**Replies:** 0\
**Last updated:** [September 24, 2019, 1:07pm UTC](https://discourse.julialang.org/t/export-trained-model-to-pmml/29110 "2019-09-24T13:07:21Z")

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Hi there, I’m trying to find a way to export an already trained model to PMML formal, so I can integrate the model in a PMML consumer (Zementis Predictive Analytics). Is there any way to do that in Julia? In R and Pyth…

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## [Paired symmetric matrix decomposition?](https://discourse.julialang.org/t/paired-symmetric-matrix-decomposition/29092)

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**Author:** [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Replies:** 1\
**Last updated:** [September 24, 2019, 7:42am UTC](https://discourse.julialang.org/t/paired-symmetric-matrix-decomposition/29092 "2019-09-24T07:42:36Z")

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Do any of the linear algebra gurus here know the name of or a citation for the following paired matrix decomposition: given symmetric matrices A and B, and an arbitrary vector v, find a decomposition of the form A = W D…

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## [In-place backslash operator for sparse matrices](https://discourse.julialang.org/t/in-place-backslash-operator-for-sparse-matrices/6091)

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**Author:** [@tryingtosolve](https://discourse.julialang.org/u/tryingtosolve)\
**Replies:** 1\
**Last updated:** [September 26, 2017, 7:17pm UTC](https://discourse.julialang.org/t/in-place-backslash-operator-for-sparse-matrices/6091 "2017-09-26T19:17:56Z")

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I have been doing A\\b where A is a sparse matrix. However, is there an in place version of \\? I have stumbled upon A\_ldiv\_B! but it seems to me (1) this function has been deprecated and (2) it didn’t work on sparse matr…

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## [Function rand() or sample() for MCMC sampling and similar?](https://discourse.julialang.org/t/function-rand-or-sample-for-mcmc-sampling-and-similar/28985)

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**Author:** [@oschulz](https://discourse.julialang.org/u/oschulz)\
**Replies:** 19\
**Last updated:** [September 23, 2019, 3:39pm UTC](https://discourse.julialang.org/t/function-rand-or-sample-for-mcmc-sampling-and-similar/28985 "2019-09-23T15:39:33Z")

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I was wondering whether to use rand() or StatsBase.sample() to name an MCMC sampling function? Some packages (e.g. AdvancedHMC.jl) use sample(), I currently use rand() (BAT.jl). There was a decision on rand() vs sample() …

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## [Using a onehot vector together with other data](https://discourse.julialang.org/t/using-a-onehot-vector-together-with-other-data/29007)

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**Author:** [@ohmsweetohm1](https://discourse.julialang.org/u/ohmsweetohm1)\
**Replies:** 2\
**Last updated:** [September 23, 2019, 8:34am UTC](https://discourse.julialang.org/t/using-a-onehot-vector-together-with-other-data/29007 "2019-09-23T08:34:56Z")

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Is it possible to use a Flux.onehot vector together with other data as input to a Layer?

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## [Zygote Performance](https://discourse.julialang.org/t/zygote-performance/29028)

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**Author:** [@cortner](https://discourse.julialang.org/u/cortner)\
**Replies:** 22\
**Last updated:** [September 23, 2019, 12:27am UTC](https://discourse.julialang.org/t/zygote-performance/29028 "2019-09-23T00:27:31Z")

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At the moment I implement gradients for all my models, because I have not yet found that Julia’s AD packages come anywhere close to my fairly naive hand-optimised gradients. (The only exception is ForwardDiff on very sma…

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## [PPL connection to MLJ.jl](https://discourse.julialang.org/t/ppl-connection-to-mlj-jl/28736)

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**Author:** [@cscherrer](https://discourse.julialang.org/u/cscherrer)\
**Replies:** 12\
**Last updated:** [September 22, 2019, 9:53pm UTC](https://discourse.julialang.org/t/ppl-connection-to-mlj-jl/28736 "2019-09-22T21:53:11Z")

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I’d like to get Soss.jl connected to MLJ.jl. I can imagine a few ways this might work, and thought I could get some input here on what could be most useful as first steps. I’ll start with a short overview, since Soss wo…

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## [Weak dependence on CUDA packages, 2019 version](https://discourse.julialang.org/t/weak-dependence-on-cuda-packages-2019-version/29033)

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**Author:** [@dfdx](https://discourse.julialang.org/u/dfdx)\
**Replies:** 3\
**Last updated:** [September 22, 2019, 2:11pm UTC](https://discourse.julialang.org/t/weak-dependence-on-cuda-packages-2019-version/29033 "2019-09-22T14:11:48Z")

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What’s state of the art for writing code with weak dependence on CUDA, e.g. when you want to provide automatic speedup if GPU is available, but provide fallback for systems with only CPUs? I remember a lot of discussion …

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## [Solving integral equation using DifferentialEquations](https://discourse.julialang.org/t/solving-integral-equation-using-differentialequations/28992)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 7\
**Last updated:** [September 20, 2019, 6:26pm UTC](https://discourse.julialang.org/t/solving-integral-equation-using-differentialequations/28992 "2019-09-20T18:26:21Z")

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Problem I need to solve an equation in x which can be simplified as an MWE into x = \\int\_{x}^\\infty A(z) dz Importantly, A(z) is decreasing, integrable, and goes to 0 at infinity. Possible solution concept I thought …

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## [\]test DiffEqGPU errors with " unsupported call to the Julia runtime"](https://discourse.julialang.org/t/test-diffeqgpu-errors-with-unsupported-call-to-the-julia-runtime/28893)

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**Author:** [@nilsbecker](https://discourse.julialang.org/u/nilsbecker)\
**Replies:** 19\
**Last updated:** [September 20, 2019, 2:39pm UTC](https://discourse.julialang.org/t/test-diffeqgpu-errors-with-unsupported-call-to-the-julia-runtime/28893 "2019-09-20T14:39:11Z")

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hi, i’m trying to experiment with ODE solving on GPUs but can’t seem to get the packages running properly. this is on a machine with CUDA 9.0 installed and 4 Tesla K80 GPUs. i can install DiffEqGPU but the test fails as…

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## [Synchronizing Cuda kernels](https://discourse.julialang.org/t/synchronizing-cuda-kernels/28220)

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**Author:** [@wiktorkujawa](https://discourse.julialang.org/u/wiktorkujawa)\
**Replies:** 5\
**Last updated:** [September 20, 2019, 5:49am UTC](https://discourse.julialang.org/t/synchronizing-cuda-kernels/28220 "2019-09-20T05:49:45Z")

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I have two cuda functions in my code: @cuda blocks=3 threads=numberofsegments+1 divideLine(Segment,numberofsegments+1,SegmentsCalculated) @cuda blocks=lenX,lenY,lenZ threads=numberofsegments,2,1 biotGPU(x,y,z,SegmentsCa…

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## [CuArray is Row Major or Column Major?](https://discourse.julialang.org/t/cuarray-is-row-major-or-column-major/7402)

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**Author:** [@drjoke](https://discourse.julialang.org/u/drjoke)\
**Replies:** 1\
**Last updated:** [November 30, 2017, 7:49am UTC](https://discourse.julialang.org/t/cuarray-is-row-major-or-column-major/7402 "2017-11-30T07:49:41Z")

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And does it really matter for the GPU? I read it matters if the architecture supports SIMD. I am not sure if GPU supports SIMD.

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## [Building SCIP error](https://discourse.julialang.org/t/building-scip-error/28973)

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**Author:** [@Ariel\_Cruz\_Cruz](https://discourse.julialang.org/u/Ariel_Cruz_Cruz)\
**Replies:** 2\
**Last updated:** [September 20, 2019, 2:31am UTC](https://discourse.julialang.org/t/building-scip-error/28973 "2019-09-20T02:31:44Z")

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Hi, I’m trying to add the SCIP package to solve some optimization problems. I am using Ubuntu 18.04 and I installed SCIP already. But when I try to make the Pkg.build("SCIP") I get the next error message: julia\> Pkg.bui…

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## [Gurobi for quadratic constraint problems](https://discourse.julialang.org/t/gurobi-for-quadratic-constraint-problems/28956)

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**Author:** [@Ariel\_Cruz\_Cruz](https://discourse.julialang.org/u/Ariel_Cruz_Cruz)\
**Replies:** 2\
**Last updated:** [September 19, 2019, 5:14pm UTC](https://discourse.julialang.org/t/gurobi-for-quadratic-constraint-problems/28956 "2019-09-19T17:14:48Z")

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Hi, I want to know if I can use the Gurobi solver to solve the next problem: min: ( (x1-1)^2 + (x2-2)^2 + (x3-1)^2 ) / 2 s.t.: x1, x2, x3 \>= 0 x1 \* x3 \<= 2 x2 \* x3 \<= 2 Because when I try to do that I get this error: …

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## [Optical Music Recognition](https://discourse.julialang.org/t/optical-music-recognition/28834)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 2\
**Last updated:** [September 19, 2019, 5:03pm UTC](https://discourse.julialang.org/t/optical-music-recognition/28834 "2019-09-19T17:03:02Z")

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Is anyone interested in working on OMR in Julia? Warning: I am a total novice in ML :smiley: I’ve been looking for an excuse to finally take the dive into machine/deep learning in Julia and this is a project that I c…

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## [Developing a kmer counter in Julia](https://discourse.julialang.org/t/developing-a-kmer-counter-in-julia/292)

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**Author:** [@bpr](https://discourse.julialang.org/u/bpr)\
**Replies:** 7\
**Last updated:** [September 19, 2019, 3:42pm UTC](https://discourse.julialang.org/t/developing-a-kmer-counter-in-julia/292 "2019-09-19T15:42:59Z")

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Hi, I was looking at some data using the Jellyfish program (a fast parallel kmer counter written in C++) and I was wondering how close I could get to it’s performance in Julia. Just so you know where I’m coming from, my…

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## [CUDAnative: examples using CUDA streams?](https://discourse.julialang.org/t/cudanative-examples-using-cuda-streams/24702)

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**Author:** [@samo](https://discourse.julialang.org/u/samo)\
**Replies:** 8\
**Last updated:** [September 19, 2019, 1:06pm UTC](https://discourse.julialang.org/t/cudanative-examples-using-cuda-streams/24702 "2019-09-19T13:06:24Z")

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From this topic we can see that CUDA streams are supported. Are there any code examples using CUDA streams in CUDAnative to help with first steps? I.e. how to create a stream, use it in a kernel call, sync on the stream…

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## [What can we do if the titile of the subplot overlap the xlabels](https://discourse.julialang.org/t/what-can-we-do-if-the-titile-of-the-subplot-overlap-the-xlabels/28944)

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**Author:** [@Lyupinpin](https://discourse.julialang.org/u/Lyupinpin)\
**Replies:** 1\
**Last updated:** [September 19, 2019, 1:03pm UTC](https://discourse.julialang.org/t/what-can-we-do-if-the-titile-of-the-subplot-overlap-the-xlabels/28944 "2019-09-19T13:03:57Z")

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using PyPlot clf() fig = figure("error",figsize=(10,50)) for i=1:3 subplot(3,1,i) a=rand(100) plot(a,a) ylabel(" Y",fontsize=18) xlabel("X",fontsize=18) title("L",fontsize=18) ax = gca() …

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## [Flux.jl: training fails at GPU but works on CPU](https://discourse.julialang.org/t/flux-jl-training-fails-at-gpu-but-works-on-cpu/28868)

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**Author:** [@Martijn-R](https://discourse.julialang.org/u/Martijn-R)\
**Replies:** 1\
**Last updated:** [September 19, 2019, 1:06am UTC](https://discourse.julialang.org/t/flux-jl-training-fails-at-gpu-but-works-on-cpu/28868 "2019-09-19T01:06:03Z")

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I have a Flux model that works OK on the CPU, but it fails when I switch to the GPU – see an MWE below. When I set gpu\_or\_cpu to cpu, loss drops to 0.004, but if I set it to gpu, the loss increases. I guess I am making …

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## [Is it really possible for rand to throw a zero?](https://discourse.julialang.org/t/is-it-really-possible-for-rand-to-throw-a-zero/28505)

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**Author:** [@aerdely](https://discourse.julialang.org/u/aerdely)\
**Replies:** 61\
**Last updated:** [September 18, 2019, 9:41am UTC](https://discourse.julialang.org/t/is-it-really-possible-for-rand-to-throw-a-zero/28505 "2019-09-18T09:41:23Z")

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rand documentation says it draws iid uniformly distributed values in the half-open unit interval \[0,1) which includes zero but… Is rand ever throwing a zero? I have tried several times with minimum(rand(1\_000\_000\_000)) a…

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## [Blank images and "dead pixels" in Makie](https://discourse.julialang.org/t/blank-images-and-dead-pixels-in-makie/28609)

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**Author:** [@dalarev](https://discourse.julialang.org/u/dalarev)\
**Replies:** 42\
**Last updated:** [September 18, 2019, 3:55am UTC](https://discourse.julialang.org/t/blank-images-and-dead-pixels-in-makie/28609 "2019-09-18T03:55:54Z")

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I run into blank images and “dead pixels” when running this Makie example (see below). The bottom-center image is blank, while the bottom-right image has a “dead pixel” at the bottom-right corner; hard to see, but it is…

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## [Understanding Blink windows](https://discourse.julialang.org/t/understanding-blink-windows/28852)

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**Author:** [@pdeffebach](https://discourse.julialang.org/u/pdeffebach)\
**Replies:** 0\
**Last updated:** [September 17, 2019, 2:52pm UTC](https://discourse.julialang.org/t/understanding-blink-windows/28852 "2019-09-17T14:52:52Z")

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My goal is to write a function that fills a Blink window with a table using TableView as quickly as possible. To do this I want to load a Blink window once and then let it sit idle in the background until the user calls…

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## [Packages for Variational Bayes inference? Turing?](https://discourse.julialang.org/t/packages-for-variational-bayes-inference-turing/17904)

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**Author:** [@Juan](https://discourse.julialang.org/u/Juan)\
**Replies:** 12\
**Last updated:** [September 17, 2019, 2:01pm UTC](https://discourse.julialang.org/t/packages-for-variational-bayes-inference-turing/17904 "2019-09-17T14:01:16Z")

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What is the most versatile and/or fasest Julia package for doing “Variational Bayes inference”? I’ve only found two packages: VarBayes.jl and TopicModelsVB.jl, the former seems deprecated. How can I do Variational Baye…

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