# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=459

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**Page:** 460

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## [Numerical Stability](https://discourse.julialang.org/t/numerical-stability/35617)

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**Author:** [@hytonwons](https://discourse.julialang.org/u/hytonwons)\
**Replies:** 1\
**Last updated:** [March 6, 2020, 2:23am UTC](https://discourse.julialang.org/t/numerical-stability/35617 "2020-03-06T02:23:53Z")

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Hi, recently I’ve been testing the numerical stability of my algorithms. Let me just use QR decomposition as an example. I tried to test the orthogonality (relative backward error) of the computed Q following this formu…

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## [Wrapping tests involving eval in @testset](https://discourse.julialang.org/t/wrapping-tests-involving-eval-in-testset/35257)

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**Author:** [@ablaom](https://discourse.julialang.org/u/ablaom)\
**Replies:** 2\
**Last updated:** [March 6, 2020, 12:12am UTC](https://discourse.julialang.org/t/wrapping-tests-involving-eval-in-testset/35257 "2020-03-06T00:12:45Z")

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I often get into trouble wrapping unit tests involving macros or eval in @testset. Can someone explain why the first example works but the second fails? x = 5 eval(quote @test x == 5 end …

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## [NLsolve.jl collocation divergence](https://discourse.julialang.org/t/nlsolve-jl-collocation-divergence/35256)

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**Author:** [@Honza9723](https://discourse.julialang.org/u/Honza9723)\
**Replies:** 10\
**Last updated:** [March 5, 2020, 7:19pm UTC](https://discourse.julialang.org/t/nlsolve-jl-collocation-divergence/35256 "2020-03-05T19:19:56Z")

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Hi everyone! I would like to ask for help/suggestions/advice with my code. I am trying to solve a simple macroeconomic model (plain vanilla deterministic optimal growth) using collocation with Chebyshev polynomials. To …

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## [Easiest quickest way to search DataFrame w/wildcards](https://discourse.julialang.org/t/easiest-quickest-way-to-search-dataframe-w-wildcards/35575)

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**Author:** [@Usor](https://discourse.julialang.org/u/Usor)\
**Replies:** 7\
**Last updated:** [March 5, 2020, 3:21pm UTC](https://discourse.julialang.org/t/easiest-quickest-way-to-search-dataframe-w-wildcards/35575 "2020-03-05T15:21:54Z")

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Is there an easy straightforward already existing way to search a DataFrame with a String wildcard in a specific column, and then print the found entries/rows? For example, you want to search if a certain name is in the…

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## [FLUX + Pytorch + tensorflow](https://discourse.julialang.org/t/flux-pytorch-tensorflow/35584)

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**Author:** [@JP\_Nieto](https://discourse.julialang.org/u/JP_Nieto)\
**Replies:** 0\
**Last updated:** [March 5, 2020, 3:13pm UTC](https://discourse.julialang.org/t/flux-pytorch-tensorflow/35584 "2020-03-05T15:13:20Z")

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Is it possible to integrate layers of pytorch and tensorflow in Flux models? any example?

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## [Vegalite.jl: use dots for separation sign](https://discourse.julialang.org/t/vegalite-jl-use-dots-for-separation-sign/35569)

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**Author:** [@Usor](https://discourse.julialang.org/u/Usor)\
**Replies:** 4\
**Last updated:** [March 5, 2020, 3:07pm UTC](https://discourse.julialang.org/t/vegalite-jl-use-dots-for-separation-sign/35569 "2020-03-05T15:07:36Z")

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Is there a setting to use . instead of , for digit separation in the resulting plot itself? (E.g., 1.000 instead of 1,000 for a thousand.) Alternatively, is there a setting to use a space character?

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## [IsApprox.jl uniform interface for approximate and exact equality](https://discourse.julialang.org/t/isapprox-jl-uniform-interface-for-approximate-and-exact-equality/35551)

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**Author:** [@jlapeyre](https://discourse.julialang.org/u/jlapeyre)\
**Replies:** 1\
**Last updated:** [March 5, 2020, 9:44am UTC](https://discourse.julialang.org/t/isapprox-jl-uniform-interface-for-approximate-and-exact-equality/35551 "2020-03-05T09:44:47Z")

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Sometimes I see an algorithm for a predicate duplicated because the notion of closeness varies. Eg. exact equality, (maximum over) elementwise distance, closeness in norm. This package is a quick initial attempt at addr…

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## [Looking for a script that runs the same code with different set of parameters and saves the results in different folders](https://discourse.julialang.org/t/looking-for-a-script-that-runs-the-same-code-with-different-set-of-parameters-and-saves-the-results-in-different-folders/35437)

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**Author:** [@Ujku\_KU](https://discourse.julialang.org/u/Ujku_KU)\
**Replies:** 7\
**Last updated:** [March 5, 2020, 1:38am UTC](https://discourse.julialang.org/t/looking-for-a-script-that-runs-the-same-code-with-different-set-of-parameters-and-saves-the-results-in-different-folders/35437 "2020-03-05T01:38:41Z")

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Hi guys, I am running a set of experiments and each of experiment differs from the rest by the set of the parameters which are picked by the same pool of parameters. I would like to run the experiments in a loop automati…

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## [Optimization of time-dependent parameters with time-series in chemical model](https://discourse.julialang.org/t/optimization-of-time-dependent-parameters-with-time-series-in-chemical-model/35550)

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**Author:** [@Newton-Climate](https://discourse.julialang.org/u/Newton-Climate)\
**Replies:** 0\
**Last updated:** [March 5, 2020, 1:35am UTC](https://discourse.julialang.org/t/optimization-of-time-dependent-parameters-with-time-series-in-chemical-model/35550 "2020-03-05T01:35:14Z")

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Hello All, I have a coupled set of differential equations with some-time-dependent parameters that I would like to optimize. In the code at the bottom of this post, the k\_i terms are fixed kinetic constants, the c\[inde…

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## [CUDAnative dynamic allocation](https://discourse.julialang.org/t/cudanative-dynamic-allocation/35435)

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**Author:** [@Michael\_Benton](https://discourse.julialang.org/u/Michael_Benton)\
**Replies:** 5\
**Last updated:** [March 4, 2020, 6:29pm UTC](https://discourse.julialang.org/t/cudanative-dynamic-allocation/35435 "2020-03-04T18:29:52Z")

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I need to be able to dynamically allocate in kernel. val = MArray{Tuple{4}, Float32}(undef) is a way to get static allocation with StaticArrays.jl inside a CUDA kernel I figured something like Array{Float32}(undef, 4) …

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## [\[DataFrames Question\]: 0.20 performance benchmarks](https://discourse.julialang.org/t/dataframes-question-0-20-performance-benchmarks/34044)

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**Author:** [@anandj](https://discourse.julialang.org/u/anandj)\
**Replies:** 1\
**Last updated:** [March 4, 2020, 2:51pm UTC](https://discourse.julialang.org/t/dataframes-question-0-20-performance-benchmarks/34044 "2020-03-04T14:51:56Z")

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I was looking at the 0.20 release notes and noticed that performance was mentioned 5 times. I was wondering if anyone has done general benchmarking versus the prior version. Thanks

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## [VegaLite: facet plot with running average layer](https://discourse.julialang.org/t/vegalite-facet-plot-with-running-average-layer/35463)

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**Author:** [@jtackm](https://discourse.julialang.org/u/jtackm)\
**Replies:** 3\
**Last updated:** [March 4, 2020, 12:19pm UTC](https://discourse.julialang.org/t/vegalite-facet-plot-with-running-average-layer/35463 "2020-03-04T12:19:05Z")

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I have a dataset with continuous values and would like to plot those values together with their running averages in a layered plot. Works well in this simple case: using Random, DataFrames, Queryverse Random.seed!(1234)…

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## ["The applicable method may be too new" - Inference by loading saved BSON Flux model](https://discourse.julialang.org/t/the-applicable-method-may-be-too-new-inference-by-loading-saved-bson-flux-model/33913)

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**Author:** [@jchen975](https://discourse.julialang.org/u/jchen975)\
**Replies:** 1\
**Last updated:** [March 4, 2020, 11:47am UTC](https://discourse.julialang.org/t/the-applicable-method-may-be-too-new-inference-by-loading-saved-bson-flux-model/33913 "2020-03-04T11:47:37Z")

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Hi, I was trying to do inference with a previously trained Flux CNN that was saved with BSON with the following: 38 @load model\_name model 39 model = model |\> gpu 40 data = data |\> gpu 41 42 println(type…

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## [Newcomer contributor in JuliaGeo and co. - Help me get started!](https://discourse.julialang.org/t/newcomer-contributor-in-juliageo-and-co-help-me-get-started/32480)

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**Author:** [@Datseris](https://discourse.julialang.org/u/Datseris)\
**Replies:** 28\
**Last updated:** [March 4, 2020, 9:15am UTC](https://discourse.julialang.org/t/newcomer-contributor-in-juliageo-and-co-help-me-get-started/32480 "2020-03-04T09:15:07Z")

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Hello everyone! I am George, lead dev/maintainer of JuliaDynamics and JuliaMusic. I just started my first postdoc position in the Max Planck Institute for Meteorology. My topic will be about spatiotemporal correlations a…

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## [Help setting up Julia on a cluster](https://discourse.julialang.org/t/help-setting-up-julia-on-a-cluster/5519)

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**Author:** [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Replies:** 28\
**Last updated:** [March 4, 2020, 12:10am UTC](https://discourse.julialang.org/t/help-setting-up-julia-on-a-cluster/5519 "2020-03-04T00:10:12Z")

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I am trying Julia for the first time on a HPC cluster at my university. Julia v0.6 is already installed, I have a few questions: How to install packages on a custom folder in the cluster other than .julia/v0.6, and wit…

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## [ClusterManagers.jl hangs on pbs](https://discourse.julialang.org/t/clustermanagers-jl-hangs-on-pbs/11056)

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**Author:** [@Snir\_Gazit](https://discourse.julialang.org/u/Snir_Gazit)\
**Replies:** 9\
**Last updated:** [March 3, 2020, 11:37pm UTC](https://discourse.julialang.org/t/clustermanagers-jl-hangs-on-pbs/11056 "2020-03-03T23:37:57Z")

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I am trying to run several jobs on a PBS cluster using ClusterManagers.jl. using ClusterManagers addprocs\_pbs(4,queue="batch") The job seems to hang: job id is 24, waiting for job to start ...........................…

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## [Difficulties to convert Matlab (ODE45) -\> Julia](https://discourse.julialang.org/t/difficulties-to-convert-matlab-ode45-julia/34828)

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**Author:** [@Noel\_Araujo](https://discourse.julialang.org/u/Noel_Araujo)\
**Replies:** 7\
**Last updated:** [March 3, 2020, 5:27pm UTC](https://discourse.julialang.org/t/difficulties-to-convert-matlab-ode45-julia/34828 "2020-03-03T17:27:22Z")

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I’m sorry to interrupt your morning/afternoon/evenning, but I need some help to convert a code written in Matlab into Julia. However, I cannot figure out where/why/how is going wrong :sob: I have a code to my research w…

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## [Infeasibility](https://discourse.julialang.org/t/infeasibility/35456)

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**Author:** [@ohmsweetohm1](https://discourse.julialang.org/u/ohmsweetohm1)\
**Replies:** 1\
**Last updated:** [March 3, 2020, 2:48pm UTC](https://discourse.julialang.org/t/infeasibility/35456 "2020-03-03T14:48:32Z")

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Is there a way to get some more information about why a JuMP.Model is infeasible, like e.g. Gurobi has?

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## [GraphPlot: calling gplot() inside function does often not work (in Atom)](https://discourse.julialang.org/t/graphplot-calling-gplot-inside-function-does-often-not-work-in-atom/35086)

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**Author:** [@mike\_k](https://discourse.julialang.org/u/mike_k)\
**Replies:** 2\
**Last updated:** [March 3, 2020, 8:01am UTC](https://discourse.julialang.org/t/graphplot-calling-gplot-inside-function-does-often-not-work-in-atom/35086 "2020-03-03T08:01:55Z")

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Dear community, I observe a strange behavior when plotting graphs with GraphPlot. In most cases it refuses to plot the input graph if I call gplot() via a function. However, sometimes (in rare cases) it works. Calling g…

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## [Mean of integers overflows - bug or expected behaviour?](https://discourse.julialang.org/t/mean-of-integers-overflows-bug-or-expected-behaviour/34767)

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**Author:** [@Mikhail\_Kagalenko](https://discourse.julialang.org/u/Mikhail_Kagalenko)\
**Replies:** 94\
**Last updated:** [March 3, 2020, 2:44am UTC](https://discourse.julialang.org/t/mean-of-integers-overflows-bug-or-expected-behaviour/34767 "2020-03-03T02:44:51Z")

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The function mean(), when used on Int inputs, returns a float result. However, it may silently overflow on integer arithmetic. julia\> mean(\[1,1\]\*typemax(Int)) -1 Maintainer of Statistics.jl closed the issue, saying t…

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## [JuMP 0.20.1: Possible bug in CPLEX when using generic lazy callback](https://discourse.julialang.org/t/jump-0-20-1-possible-bug-in-cplex-when-using-generic-lazy-callback/35425)

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**Author:** [@ryancorywright](https://discourse.julialang.org/u/ryancorywright)\
**Replies:** 1\
**Last updated:** [March 2, 2020, 7:29pm UTC](https://discourse.julialang.org/t/jump-0-20-1-possible-bug-in-cplex-when-using-generic-lazy-callback/35425 "2020-03-02T19:29:50Z")

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Specs: JuMP version 0.20.1, MOI version 0.9.12, CPLEX version 12.10, CPLEX.jl version 0.6.3. When using JuMP and CPLEX to solve a problem via outer approximation (using a generic lazy callback), I’m getting the followin…

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## [PowerModels in MAC OS](https://discourse.julialang.org/t/powermodels-in-mac-os/35384)

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**Author:** [@faoh](https://discourse.julialang.org/u/faoh)\
**Replies:** 5\
**Last updated:** [March 2, 2020, 4:42pm UTC](https://discourse.julialang.org/t/powermodels-in-mac-os/35384 "2020-03-02T16:42:23Z")

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When I try to use build\_model to see the optimization model, it shows ‘UndefVarError: build\_model not defined’. The code is pm = build\_model(“~/PowerModels.jl-master/test/data/matpower/case5\_tnep.m”, ACPPowerModel, Po…

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## [@ode\_def macro leads to UndefRefError: access to undefined reference](https://discourse.julialang.org/t/ode-def-macro-leads-to-undefreferror-access-to-undefined-reference/35330)

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**Author:** [@joergbuchwald](https://discourse.julialang.org/u/joergbuchwald)\
**Replies:** 7\
**Last updated:** [March 2, 2020, 12:55pm UTC](https://discourse.julialang.org/t/ode-def-macro-leads-to-undefreferror-access-to-undefined-reference/35330 "2020-03-02T12:55:39Z")

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Hi, I tried to use the @ode\_def macro, but somehow got stuck in an UndefRefError: julia\> sir\_ode = @ode\_def SIRModel begin dS = -β\*S\*I dI = β\*S\*I-γ\*I dR = γ\*I end β γ ┌ Warni…

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## [How to set labels for eached coloured bar in Plots.jl's bar()?](https://discourse.julialang.org/t/how-to-set-labels-for-eached-coloured-bar-in-plots-jls-bar/9312)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 11\
**Last updated:** [March 2, 2020, 11:00am UTC](https://discourse.julialang.org/t/how-to-set-labels-for-eached-coloured-bar-in-plots-jls-bar/9312 "2020-03-02T11:00:28Z")

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bar( \["a","b","c"\], \[1,2,3\], fillcolor = categorical(\["a","b","c"\]).refs, labels = \["a","b","c"\] ) I can make the plot with the above code, but I can’t seem to work out how to make the labels follow the …

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## [Interest in co-developing a library for Positive Matrix Factorization (PMF)](https://discourse.julialang.org/t/interest-in-co-developing-a-library-for-positive-matrix-factorization-pmf/25189)

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**Author:** [@dhhagan](https://discourse.julialang.org/u/dhhagan)\
**Replies:** 3\
**Last updated:** [March 2, 2020, 10:52am UTC](https://discourse.julialang.org/t/interest-in-co-developing-a-library-for-positive-matrix-factorization-pmf/25189 "2020-03-02T10:52:16Z")

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Positive Matrix Factorization (PMF; Paatero, 1997) is a factorization method commonly used in the environmental sciences since unlike nonnegative matrix factorization (NMF), it utilizes known uncertainties to weight the …

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## [Yay, I finally managed to define my custom kernel. But now I need it to be fast(er)](https://discourse.julialang.org/t/yay-i-finally-managed-to-define-my-custom-kernel-but-now-i-need-it-to-be-fast-er/34398)

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**Author:** [@izzorts](https://discourse.julialang.org/u/izzorts)\
**Replies:** 6\
**Last updated:** [March 2, 2020, 10:39am UTC](https://discourse.julialang.org/t/yay-i-finally-managed-to-define-my-custom-kernel-but-now-i-need-it-to-be-fast-er/34398 "2020-03-02T10:39:41Z")

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Hi! It’s been about a week that I started learning GPGPU in Julia. At first I used ArrayFire, but then I needed to do some more sophisticated computations on the GPU and started trying to define my own custom kernels via…

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## [CUDAnative: would it be possible to specify interface arguments rather than kernel arguments?](https://discourse.julialang.org/t/cudanative-would-it-be-possible-to-specify-interface-arguments-rather-than-kernel-arguments/35282)

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**Author:** [@samo](https://discourse.julialang.org/u/samo)\
**Replies:** 2\
**Last updated:** [March 2, 2020, 9:24am UTC](https://discourse.julialang.org/t/cudanative-would-it-be-possible-to-specify-interface-arguments-rather-than-kernel-arguments/35282 "2020-03-02T09:24:16Z")

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Issue Let’s consider the following simple CUDAnative example: julia\> using CuArrays, CUDAnative julia\> A = CuArrays.zeros(2,2) 2×2 CuArray{Float32,2}: 0.0 0.0 0.0 0.0 julia\> B = CuArrays.ones(2,2) 2×2 CuArray{Floa…

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## [Excel not recognize automatically generated CSV files using utf-8 encoding](https://discourse.julialang.org/t/excel-not-recognize-automatically-generated-csv-files-using-utf-8-encoding/35258)

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**Author:** [@JosephPollacco](https://discourse.julialang.org/u/JosephPollacco)\
**Replies:** 9\
**Last updated:** [March 1, 2020, 9:46pm UTC](https://discourse.julialang.org/t/excel-not-recognize-automatically-generated-csv-files-using-utf-8-encoding/35258 "2020-03-01T21:46:51Z")

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I generate utf-8 encoding output in Julia by using DelimitedFiles package. I would like students to be able to read the generated files automatically in EXCEL by using utf-8 encoding without going into the pain in Excel…

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## [Interest in a port of snorkel?](https://discourse.julialang.org/t/interest-in-a-port-of-snorkel/35349)

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**Author:** [@a5vzener](https://discourse.julialang.org/u/a5vzener)\
**Replies:** 0\
**Last updated:** [March 1, 2020, 4:52am UTC](https://discourse.julialang.org/t/interest-in-a-port-of-snorkel/35349 "2020-03-01T04:52:27Z")

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Has anyone used snorkel, a python package for efficient data set labeling? Does this seem like a good algorithm or system to be ported to Julia? -doug

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## [How do i show plots in a PDF generated through Weave?](https://discourse.julialang.org/t/how-do-i-show-plots-in-a-pdf-generated-through-weave/35346)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 2\
**Last updated:** [March 1, 2020, 1:45am UTC](https://discourse.julialang.org/t/how-do-i-show-plots-in-a-pdf-generated-through-weave/35346 "2020-03-01T01:45:16Z")

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Using this code, I’m able to turn my .jl file into a pdf, including calculations weave("Soc323.jl", out\_path = "C:/Users/brett/OneDrive/Documents", doctype = "md2pdf") but none of my plots are included, is there a comm…

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