# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=329

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**Page:** 330

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## [Using LightGraphs to study ODEproblems](https://discourse.julialang.org/t/using-lightgraphs-to-study-odeproblems/69545)

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**Author:** [@Frazze](https://discourse.julialang.org/u/Frazze)\
**Replies:** 3\
**Last updated:** [October 14, 2021, 10:41am UTC](https://discourse.julialang.org/t/using-lightgraphs-to-study-odeproblems/69545 "2021-10-14T10:41:33Z")

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Hi everyone, I’m studying an ODEProblem where the function have a laplacian operator. #Domain and grid Nx = 40 Ny = 40 lx = 12 ly = 12 # the Laplacian operator function Laplacian2D(Nx, Ny, lx, ly) hx = lx/Nx hy = l…

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## [Compressed array-on-disk](https://discourse.julialang.org/t/compressed-array-on-disk/69410)

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**Author:** [@grero](https://discourse.julialang.org/u/grero)\
**Replies:** 9\
**Last updated:** [October 11, 2021, 1:36pm UTC](https://discourse.julialang.org/t/compressed-array-on-disk/69410 "2021-10-11T13:36:51Z")

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I am working on an algorithm that fits an HMM model to some data. As part of the fitting I need to run the so-called \[forward-backward\] algorithm (Forward–backward algorithm - Wikipedia). This involves constructing matri…

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## [Custom \<span\> using Documenter.jl](https://discourse.julialang.org/t/custom-span-using-documenter-jl/69727)

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**Author:** [@ettersi](https://discourse.julialang.org/u/ettersi)\
**Replies:** 0\
**Last updated:** [October 14, 2021, 4:49am UTC](https://discourse.julialang.org/t/custom-span-using-documenter-jl/69727 "2021-10-14T04:49:09Z")

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How can I insert a custom \<span\> element in a Documenter.jl markdown file? Specifically, I would like to create HTML like the following: Lorem ipsum \<span style="color: #f00;"\>dolor\</span\> sit amet. The following bit…

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## [Julia animation using PlotlyJS](https://discourse.julialang.org/t/julia-animation-using-plotlyjs/69684)

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**Author:** [@cvalero](https://discourse.julialang.org/u/cvalero)\
**Replies:** 0\
**Last updated:** [October 13, 2021, 12:47pm UTC](https://discourse.julialang.org/t/julia-animation-using-plotlyjs/69684 "2021-10-13T12:47:17Z")

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Hi, I am happy to share some code that shows how to do animations using Julia and PlotlyJS on a Jupyter Notebook. On the first cell of a Jupyter Notebook insert using PlotlyJS t = LinRange(0.0,2\*pi,250) ω1 = 2 ω2 = …

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## [Tokyo 2020 Olympic Medals](https://discourse.julialang.org/t/tokyo-2020-olympic-medals/69641)

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**Author:** [@cepel](https://discourse.julialang.org/u/cepel)\
**Replies:** 1\
**Last updated:** [October 13, 2021, 6:45pm UTC](https://discourse.julialang.org/t/tokyo-2020-olympic-medals/69641 "2021-10-13T18:45:41Z")

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Hey everyone! I developed a Dash Julia application to visualize Tokyo 2020 Olympic Medals of teams, and open-sourced all the codes. You can see the application here: Live on Heroku ← Click Here GitHub ← Click Here (…

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## [Seg Fault caused by loading a giant model](https://discourse.julialang.org/t/seg-fault-caused-by-loading-a-giant-model/69588)

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**Author:** [@Tyler\_Ingebrand](https://discourse.julialang.org/u/Tyler_Ingebrand)\
**Replies:** 1\
**Last updated:** [October 13, 2021, 6:01pm UTC](https://discourse.julialang.org/t/seg-fault-caused-by-loading-a-giant-model/69588 "2021-10-13T18:01:24Z")

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When using BSON, I am getting a seg fault when trying to load a saved model. Details below. The model is originally saved with: bson(savedir \* "policy.bson", policy = final\_policy) Then, in a different module, I am t…

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## [Setting heuristic solution involving symmetric matrix in JuMP callback](https://discourse.julialang.org/t/setting-heuristic-solution-involving-symmetric-matrix-in-jump-callback/69621)

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**Author:** [@Shuvomoy\_Das\_Gupta](https://discourse.julialang.org/u/Shuvomoy_Das_Gupta)\
**Replies:** 7\
**Last updated:** [October 13, 2021, 5:11pm UTC](https://discourse.julialang.org/t/setting-heuristic-solution-involving-symmetric-matrix-in-jump-callback/69621 "2021-10-13T17:11:52Z")

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Dear All, I am experimenting with JuMP callback with Gurobi’s MIQCP feature, where I am storing the heuristic values based on tips from https://discourse.julialang.org/t/jump-cplex-how-to-set-heuristic-solution-using-sp…

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## [Defining constraints using JuMP](https://discourse.julialang.org/t/defining-constraints-using-jump/69659)

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**Author:** [@FH96](https://discourse.julialang.org/u/FH96)\
**Replies:** 4\
**Last updated:** [October 13, 2021, 1:43pm UTC](https://discourse.julialang.org/t/defining-constraints-using-jump/69659 "2021-10-13T13:43:42Z")

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while defining constraints in a nonlinear optimization problem ,I face this error: “MethodError: no method matching \*(::DataFrame, ::Vector{VariableRef}))” can anyone help? here’s part of my code: s\_matrix\_df=DataFra…

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## [Nested cross-validation](https://discourse.julialang.org/t/nested-cross-validation/65089)

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**Author:** [@rikh](https://discourse.julialang.org/u/rikh)\
**Replies:** 3\
**Last updated:** [October 13, 2021, 9:45am UTC](https://discourse.julialang.org/t/nested-cross-validation/65089 "2021-10-13T09:45:21Z")

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For my PhD, I’m mainly dealing with data containing 10 to 20 features and sample sizes of about 100 to 500. According to quite some literature, cross-validation (CV) is biased and should be replaced by nested cross-valid…

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## [Differential Equations: resolving instability in ODE problem](https://discourse.julialang.org/t/differential-equations-resolving-instability-in-ode-problem/69671)

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**Author:** [@spinystellate](https://discourse.julialang.org/u/spinystellate)\
**Replies:** 1\
**Last updated:** [October 13, 2021, 9:29am UTC](https://discourse.julialang.org/t/differential-equations-resolving-instability-in-ode-problem/69671 "2021-10-13T09:29:22Z")

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I am trying to transfer a Matlab model to Julia, but am running into instability issues. I have found this discussion: \[Handling Instability When Solving ODE Problems\] and tried some of the suggested actions, but am st…

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## [Derivative of a registered function](https://discourse.julialang.org/t/derivative-of-a-registered-function/69656)

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**Author:** [@PikaPei](https://discourse.julialang.org/u/PikaPei)\
**Replies:** 2\
**Last updated:** [October 13, 2021, 7:03am UTC](https://discourse.julialang.org/t/derivative-of-a-registered-function/69656 "2021-10-13T07:03:27Z")

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I want to compute some Jacobian matrix and get the numerical value. However, if I registered the user-defined function, I can’t get the result. For example, before @register: using ModelingToolkit @parameters t D = D…

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## [AsVector is impressive why it's not implemented yet](https://discourse.julialang.org/t/asvector-is-impressive-why-its-not-implemented-yet/69500)

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**Author:** [@xinchin](https://discourse.julialang.org/u/xinchin)\
**Replies:** 2\
**Last updated:** [October 13, 2021, 5:14am UTC](https://discourse.julialang.org/t/asvector-is-impressive-why-its-not-implemented-yet/69500 "2021-10-13T05:14:22Z")

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I come up across this issue https://github.com/JuliaData/DataFrames.jl/issues/2440 and I was amazed by the idea and the capability of Julia language. I learnt a lot from the code, but wonder why it is not implemented y…

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## [TextModels PoSTagger error due to Flux.jl](https://discourse.julialang.org/t/textmodels-postagger-error-due-to-flux-jl/69514)

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**Author:** [@Maxim\_Lubov](https://discourse.julialang.org/u/Maxim_Lubov)\
**Replies:** 3\
**Last updated:** [October 13, 2021, 3:44am UTC](https://discourse.julialang.org/t/textmodels-postagger-error-due-to-flux-jl/69514 "2021-10-13T03:44:39Z")

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I have a problem with TextAnalysis PoSTagger. When I try to load PoSTagger: pos = PoSTagger() the following error occurs: ERROR: LoadError: MethodError: no method matching Flux.Conv(::typeof(identity), ::Array{Float3…

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## [Visual bug with CairoMakie in Notebooks](https://discourse.julialang.org/t/visual-bug-with-cairomakie-in-notebooks/69436)

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**Author:** [@jedforrest](https://discourse.julialang.org/u/jedforrest)\
**Replies:** 3\
**Last updated:** [October 13, 2021, 3:28am UTC](https://discourse.julialang.org/t/visual-bug-with-cairomakie-in-notebooks/69436 "2021-10-13T03:28:22Z")

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Hi, I think I found a very specific rendering bug when using CairoMakie and Julia Notebooks. Running the following code in successive notebook cells produces the rendering error in the second plot. The orange line in t…

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## [How to export the coefficient matrix of JuMP model?](https://discourse.julialang.org/t/how-to-export-the-coefficient-matrix-of-jump-model/69635)

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**Author:** [@iiitr](https://discourse.julialang.org/u/iiitr)\
**Replies:** 1\
**Last updated:** [October 12, 2021, 8:53pm UTC](https://discourse.julialang.org/t/how-to-export-the-coefficient-matrix-of-jump-model/69635 "2021-10-12T20:53:29Z")

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Hi all, In Matlab/Yalmip, we can using export, we can get the coefficient matrix and several “standard form” based on certain solver. For example, if we use Gurobi, we can use export to get A, rhs, sense, vtype, obj… I…

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## [Transformers for NER classification](https://discourse.julialang.org/t/transformers-for-ner-classification/69300)

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**Author:** [@Maxim\_Lubov](https://discourse.julialang.org/u/Maxim_Lubov)\
**Replies:** 9\
**Last updated:** [October 12, 2021, 6:07pm UTC](https://discourse.julialang.org/t/transformers-for-ner-classification/69300 "2021-10-12T18:07:15Z")

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Hello. I am building a model for NER classification. Model is based on pre-trained BERT loaded with Transformers. I have some problems with the loss function. The problem is, that all losses are calculated only for the s…

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## [Unbalanced One-way ANOVA](https://discourse.julialang.org/t/unbalanced-one-way-anova/69489)

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**Author:** [@AerospaceMark](https://discourse.julialang.org/u/AerospaceMark)\
**Replies:** 4\
**Last updated:** [October 12, 2021, 12:46pm UTC](https://discourse.julialang.org/t/unbalanced-one-way-anova/69489 "2021-10-12T12:46:55Z")

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I’m a graduate student seeking to learn how to do statistics in Julia. From my internet searching and working with the SimpleANOVA package, I’ve been able to perform ANOVA tests on data where each group has the same numb…

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## [Wrong to add mosek](https://discourse.julialang.org/t/wrong-to-add-mosek/69605)

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**Author:** [@wangpuming](https://discourse.julialang.org/u/wangpuming)\
**Replies:** 3\
**Last updated:** [October 12, 2021, 12:13pm UTC](https://discourse.julialang.org/t/wrong-to-add-mosek/69605 "2021-10-12T12:13:09Z")

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I tried Pkg.add(“Mosek”) to add Mosek package, but I got following errors when I use it.(I have installed the license.) I have no idea why I have received these errors. Please let me know if you have been in the same sit…

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## [Communication between QML and Julia](https://discourse.julialang.org/t/communication-between-qml-and-julia/69617)

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**Author:** [@etas](https://discourse.julialang.org/u/etas)\
**Replies:** 0\
**Last updated:** [October 12, 2021, 12:03pm UTC](https://discourse.julialang.org/t/communication-between-qml-and-julia/69617 "2021-10-12T12:03:37Z")

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Hi, I’m trying to make a light UI with QML but I didn’t find the way to call Julia functions from QML with a vector as parameter and to use this vector in Julia. This example calls the Julia function fct1 when a button, …

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## [A little tax-benefit simulation](https://discourse.julialang.org/t/a-little-tax-benefit-simulation/69615)

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**Author:** [@grahamstark](https://discourse.julialang.org/u/grahamstark)\
**Replies:** 0\
**Last updated:** [October 12, 2021, 11:45am UTC](https://discourse.julialang.org/t/a-little-tax-benefit-simulation/69615 "2021-10-12T11:45:11Z")

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Hi, I thought I’d share this: https://stb.virtual-worlds.scot/bcd/ it’s a tax-benefit simulation of budget constraints for the UK (specifically, Scotland). Built in Julia and Dash, it how shows the net income of a hou…

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## [Working with a cluster: Data storage & JuliaDB workflow?](https://discourse.julialang.org/t/working-with-a-cluster-data-storage-juliadb-workflow/69544)

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**Author:** [@volkerkarle](https://discourse.julialang.org/u/volkerkarle)\
**Replies:** 7\
**Last updated:** [October 12, 2021, 11:31am UTC](https://discourse.julialang.org/t/working-with-a-cluster-data-storage-juliadb-workflow/69544 "2021-10-12T11:31:25Z")

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Dear folks, My Problem: Assume I work on a cluster spawning thousands of jobs (in parallel) and each job saves its outcome in some .hdf5 or .jld file. After all jobs have finished, I collect the data and put them in one…

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## [Status of Plotly Availability / Development in Julia?](https://discourse.julialang.org/t/status-of-plotly-availability-development-in-julia/69553)

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**Author:** [@Dieter](https://discourse.julialang.org/u/Dieter)\
**Replies:** 11\
**Last updated:** [October 12, 2021, 5:25am UTC](https://discourse.julialang.org/t/status-of-plotly-availability-development-in-julia/69553 "2021-10-12T05:25:29Z")

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Hi Community, I am quite new in Julia but I have already seen that Plotly does a great job in creating interactive plots. But it seems that https://plotly.com/julia/ has a lot of dead links such as https://plotly.com/j…

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## [Column Gerneration Example in the documentation/hot start after adding variables to LP](https://discourse.julialang.org/t/column-gerneration-example-in-the-documentation-hot-start-after-adding-variables-to-lp/69603)

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**Author:** [@dirk](https://discourse.julialang.org/u/dirk)\
**Replies:** 1\
**Last updated:** [October 12, 2021, 4:40am UTC](https://discourse.julialang.org/t/column-gerneration-example-in-the-documentation-hot-start-after-adding-variables-to-lp/69603 "2021-10-12T04:40:31Z")

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Hi all, I just started using Julia and JuMP. I went through the tutorials (https://jump.dev/JuMP.jl/stable/tutorials/Mixed-integer%20linear%20programs/cutting\_stock\_column\_generation/) and in the column generation exam…

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## [Fastest way to add many JuMP constraints](https://discourse.julialang.org/t/fastest-way-to-add-many-jump-constraints/69587)

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**Author:** [@ZHEN\_LIN](https://discourse.julialang.org/u/ZHEN_LIN)\
**Replies:** 6\
**Last updated:** [October 12, 2021, 3:08am UTC](https://discourse.julialang.org/t/fastest-way-to-add-many-jump-constraints/69587 "2021-10-12T03:08:43Z")

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What is the best way to add the following constraints in JuMP to minimize computation time? I need to solve similar models many times. @constraint(model, \[i = 1:n, j = 1:m\], \[t\[i, j\], 1, x\[i, j\]\] in MOI.ExponentialCone(…

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## [(Flux) Moving data between cpu and gpu: "This intrinsic must be compiled to be called"](https://discourse.julialang.org/t/flux-moving-data-between-cpu-and-gpu-this-intrinsic-must-be-compiled-to-be-called/69595)

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**Author:** [@c-state](https://discourse.julialang.org/u/c-state)\
**Replies:** 1\
**Last updated:** [October 12, 2021, 2:08am UTC](https://discourse.julialang.org/t/flux-moving-data-between-cpu-and-gpu-this-intrinsic-must-be-compiled-to-be-called/69595 "2021-10-12T02:08:35Z")

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The title and example really say it all. I’m using Flux.jl version 0.12.7 and CUDA.jl 3.5.0. MWE: julia\> using Flux julia\> x = \[1, 2\] 2-element Vector{Int64}: 1 2 julia\> Flux.pullback(() -\> gpu(x)) ERROR: this intr…

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## [Qs about trained model: (1) testmode! vs excluding Dropout layers; (2) size of BSON file](https://discourse.julialang.org/t/qs-about-trained-model-1-testmode-vs-excluding-dropout-layers-2-size-of-bson-file/69572)

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**Author:** [@Maxim\_Lubov](https://discourse.julialang.org/u/Maxim_Lubov)\
**Replies:** 3\
**Last updated:** [October 11, 2021, 11:44pm UTC](https://discourse.julialang.org/t/qs-about-trained-model-1-testmode-vs-excluding-dropout-layers-2-size-of-bson-file/69572 "2021-10-11T23:44:07Z")

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(1) I trained the NN model and want to use it further, i.e, load from the disk. What is the best way to predict: (i) with Flux.testmode! and Dropout layers; (ii) without Dropout layers and without Flux.testmode!? (2) My…

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## [Is there a way to serialize a CURAND RNG?](https://discourse.julialang.org/t/is-there-a-way-to-serialize-a-curand-rng/34493)

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**Author:** [@marius311](https://discourse.julialang.org/u/marius311)\
**Replies:** 2\
**Last updated:** [October 11, 2021, 9:15pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-serialize-a-curand-rng/34493 "2021-10-11T21:15:16Z")

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With Base, I can take the RNG returned by Random.default\_rng(), write it to file with eg JLD2, then later reload it and reproduce my random number sequence from that point. Is something like this possible with CURAND? I…

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## [CellListMap.jl / CellListMap.florpi documentation](https://discourse.julialang.org/t/celllistmap-jl-celllistmap-florpi-documentation/68390)

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**Author:** [@j\_u](https://discourse.julialang.org/u/j_u)\
**Replies:** 2\
**Last updated:** [October 11, 2021, 7:21pm UTC](https://discourse.julialang.org/t/celllistmap-jl-celllistmap-florpi-documentation/68390 "2021-10-11T19:21:28Z")

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Is there any documentation on CellListMap.florpi “function” / “code” that computes pairwise velocity distributions? Any additional information like github documentation, research paper, accessible explanation in literatu…

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## [Transparent series points on a plot](https://discourse.julialang.org/t/transparent-series-points-on-a-plot/69569)

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**Author:** [@pthompson234](https://discourse.julialang.org/u/pthompson234)\
**Replies:** 1\
**Last updated:** [October 11, 2021, 4:43pm UTC](https://discourse.julialang.org/t/transparent-series-points-on-a-plot/69569 "2021-10-11T16:43:18Z")

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Hi, this may be a simple question, but I would like to make a scatter plot where all markers have the same color, but some are more transparent than others. To do this, I have constructed a vector of RGBA objects, like b…

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## [How to suppress specific warning?](https://discourse.julialang.org/t/how-to-suppress-specific-warning/69502)

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**Author:** [@Ahmed\_Salih](https://discourse.julialang.org/u/Ahmed_Salih)\
**Replies:** 6\
**Last updated:** [October 11, 2021, 1:55pm UTC](https://discourse.julialang.org/t/how-to-suppress-specific-warning/69502 "2021-10-11T13:55:43Z")

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I get the following warning when plotting two surfaces with different colors but only showing one colorbar, which is what I want: ┌ Warning: Multiple series with different fill alpha share a colorbar. Colorbar may not r…

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