# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=263

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**Page:** 264

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## [Any packages for Point Cloud Registration](https://discourse.julialang.org/t/any-packages-for-point-cloud-registration/54679)

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**Author:** [@Wikunia](https://discourse.julialang.org/u/Wikunia)\
**Replies:** 3\
**Last updated:** [July 25, 2022, 8:23pm UTC](https://discourse.julialang.org/t/any-packages-for-point-cloud-registration/54679 "2022-07-25T20:23:02Z")

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I’m currently looking for a library that can solve or assist solving the following problem. I have a bunch of 3D point clouds from different angles and would like to combine them to have a single 3d point cloud. Seems l…

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## [How to gain access variables as soons as they are assigned a value?](https://discourse.julialang.org/t/how-to-gain-access-variables-as-soons-as-they-are-assigned-a-value/84747)

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**Author:** [@Optimization](https://discourse.julialang.org/u/Optimization)\
**Replies:** 5\
**Last updated:** [July 25, 2022, 7:55pm UTC](https://discourse.julialang.org/t/how-to-gain-access-variables-as-soons-as-they-are-assigned-a-value/84747 "2022-07-25T19:55:47Z")

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I was wondering whether in JuMP is possible to be aware of the value of variables while the model is still running?? I mean, suppose we have a set of binary variables x(i,j) i,j in \[1,2,3,...,n\]. Is there any possiblit…

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## [GUI package for a "real-time" control application](https://discourse.julialang.org/t/gui-package-for-a-real-time-control-application/84673)

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**Author:** [@Hawkes](https://discourse.julialang.org/u/Hawkes)\
**Replies:** 30\
**Last updated:** [July 25, 2022, 6:01pm UTC](https://discourse.julialang.org/t/gui-package-for-a-real-time-control-application/84673 "2022-07-25T18:01:23Z")

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Hi, since some time I’m wondering how to (i.e. using which GUI library) to build a GUI-based control/measurement application using Julia. In the past I have used Python + PyQt + PyQtGraph to create quite performant GUIs…

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## [Using CellListMap.jl within Agents.jl framework](https://discourse.julialang.org/t/using-celllistmap-jl-within-agents-jl-framework/84709)

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**Author:** [@ehsani63](https://discourse.julialang.org/u/ehsani63)\
**Replies:** 15\
**Last updated:** [July 25, 2022, 5:26pm UTC](https://discourse.julialang.org/t/using-celllistmap-jl-within-agents-jl-framework/84709 "2022-07-25T17:26:02Z")

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Hi, I am using CellListMap in one of my ABM simulations (using Agents.jl). It suits very well what I want to do: There some active agents and some static obstacles. CellListMap finds collisions between agents and obstacl…

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## [Converting a PyCall numpy ×3 Array{UInt8, 3} to RGB](https://discourse.julialang.org/t/converting-a-pycall-numpy-x3-array-uint8-3-to-rgb/70537)

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**Author:** [@Pytrator](https://discourse.julialang.org/u/Pytrator)\
**Replies:** 3\
**Last updated:** [July 25, 2022, 5:26pm UTC](https://discourse.julialang.org/t/converting-a-pycall-numpy-x3-array-uint8-3-to-rgb/70537 "2022-07-25T17:26:01Z")

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Hey guys, I use the NumPy per PyCall to get screenshots of my desktop. I get these images back as 1440×3440×3 Array{UInt8, 3} Discord user borodi#9175 already shared a function of him that converts this array to a BGR. …

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## [How to generate a reusable static LLVM IR module?](https://discourse.julialang.org/t/how-to-generate-a-reusable-static-llvm-ir-module/83226)

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**Author:** [@knlv.ok](https://discourse.julialang.org/u/knlv.ok)\
**Replies:** 4\
**Last updated:** [July 25, 2022, 11:44am UTC](https://discourse.julialang.org/t/how-to-generate-a-reusable-static-llvm-ir-module/83226 "2022-07-25T11:44:21Z")

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Hello, I am a beginner in Julia programming. I need a way to generate a static LLVM IR module for functions written in Julia and modify the LLVM IR that was generated. I saw on CUDAnative.jl , there are some features …

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## [Does MultiJuMP.jl have multithreading or multi-core support?](https://discourse.julialang.org/t/does-multijump-jl-have-multithreading-or-multi-core-support/84739)

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**Author:** [@chenr86](https://discourse.julialang.org/u/chenr86)\
**Replies:** 1\
**Last updated:** [July 25, 2022, 8:40am UTC](https://discourse.julialang.org/t/does-multijump-jl-have-multithreading-or-multi-core-support/84739 "2022-07-25T08:40:43Z")

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Hello, I’m using MultiJuMP.jl and Juniper to solve an MINLP problem. It takes more than 2 hours to optimize the problem using one core. I wonder how can I accelerate the calculation process. Can I run my code with multi…

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## [How do I get PyPlot to always be in interactive mode in the REPL?](https://discourse.julialang.org/t/how-do-i-get-pyplot-to-always-be-in-interactive-mode-in-the-repl/84724)

<div class="topic-metadata">

**Author:** [@danielc](https://discourse.julialang.org/u/danielc)\
**Replies:** 0\
**Last updated:** [July 24, 2022, 8:23pm UTC](https://discourse.julialang.org/t/how-do-i-get-pyplot-to-always-be-in-interactive-mode-in-the-repl/84724 "2022-07-24T20:23:36Z")

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So I recently had to reinstall Julia and I just can’t get PyPlot working the way it should. In the REPL, PyPlot defaults to interactive mode, meaning that plots are updated immediately and you don’t have to run show(). E…

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## [Fast, simple graphics?](https://discourse.julialang.org/t/fast-simple-graphics/84694)

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**Author:** [@Nathaniel](https://discourse.julialang.org/u/Nathaniel)\
**Replies:** 12\
**Last updated:** [July 24, 2022, 8:09am UTC](https://discourse.julialang.org/t/fast-simple-graphics/84694 "2022-07-24T08:09:47Z")

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I’m running a simulation and would like to watch my agents moving around as the simulation runs. Currently, I’m using Plots, just running plot(...) in a loop. However, this is very slow - plotting each frame takes at lea…

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## [Julia package dealing with propagation of uncertainty](https://discourse.julialang.org/t/julia-package-dealing-with-propagation-of-uncertainty/84472)

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**Author:** [@Firstname\_Lastname](https://discourse.julialang.org/u/Firstname_Lastname)\
**Replies:** 3\
**Last updated:** [July 23, 2022, 11:39pm UTC](https://discourse.julialang.org/t/julia-package-dealing-with-propagation-of-uncertainty/84472 "2022-07-23T23:39:40Z")

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In a static problem, there is uncertainty in some input, like I = a \\pm b. The output \[a function of spatial variables, i.e. f(x,y)\] is uncertain due to uncertain input. For each input sample, randomly generated, the fun…

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## [Saving time-dependent variable inside ODE](https://discourse.julialang.org/t/saving-time-dependent-variable-inside-ode/84552)

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**Author:** [@jpro](https://discourse.julialang.org/u/jpro)\
**Replies:** 7\
**Last updated:** [July 23, 2022, 11:30pm UTC](https://discourse.julialang.org/t/saving-time-dependent-variable-inside-ode/84552 "2022-07-23T23:30:50Z")

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Hi, I’d like to extract time-dependent variable from inside an ODE, but am having trouble doing so given that it is not in the state vector. I have my du function (called pendulum!) inside a system function. I use this s…

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## [Multiple Makie display windows](https://discourse.julialang.org/t/multiple-makie-display-windows/26295)

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**Author:** [@babaq](https://discourse.julialang.org/u/babaq)\
**Replies:** 21\
**Last updated:** [July 23, 2022, 4:45pm UTC](https://discourse.julialang.org/t/multiple-makie-display-windows/26295 "2022-07-23T16:45:56Z")

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Hi, I am wandering if multiply Makie Display Windows could be created with different scenes, could be very useful when compare several 3D plots.

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## [Nested groupby](https://discourse.julialang.org/t/nested-groupby/78958)

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**Author:** [@rocco\_sprmnt21](https://discourse.julialang.org/u/rocco_sprmnt21)\
**Replies:** 9\
**Last updated:** [July 23, 2022, 5:17am UTC](https://discourse.julialang.org/t/nested-groupby/78958 "2022-07-23T05:17:36Z")

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trying to understand the role of kwarg isgathered, I practiced this exercise. julia\> ds = Dataset(id = \[1,1,1,1,1,2,2,2,3,3,3\], date = Date.(\["2019-03-05", "2019-03-12", "2019-04-10", …

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## [Leftjoin with replacement](https://discourse.julialang.org/t/leftjoin-with-replacement/83457)

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**Author:** [@alfaromartino](https://discourse.julialang.org/u/alfaromartino)\
**Replies:** 3\
**Last updated:** [July 23, 2022, 5:15am UTC](https://discourse.julialang.org/t/leftjoin-with-replacement/83457 "2022-07-23T05:15:46Z")

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I thought of an option that seems a natural extension of leftjoin. Suppose that you have two dataframes, where one is a strict subset of the other. df1 = DataFrame(ID=\[1, 2, 3\], Name=\["John Doe", "Jane Doe", "Joe Blogs"…

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## [NLopt return flag: is there a simple way to check for success?](https://discourse.julialang.org/t/nlopt-return-flag-is-there-a-simple-way-to-check-for-success/84637)

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**Author:** [@mcreel](https://discourse.julialang.org/u/mcreel)\
**Replies:** 2\
**Last updated:** [July 23, 2022, 4:35am UTC](https://discourse.julialang.org/t/nlopt-return-flag-is-there-a-simple-way-to-check-for-success/84637 "2022-07-23T04:35:50Z")

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NLopt.optimize returns a tuple (objvalue, xopt, flag), and flag is a symbol that can hold strings such as FTOL\_REACHED or SUCCESS. The C API mentions that positive return values indicate success. Is there a similar way t…

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## [LinearAlgebra./ breaks CuArray](https://discourse.julialang.org/t/linearalgebra-breaks-cuarray/84570)

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**Author:** [@Lian\_Yunlong](https://discourse.julialang.org/u/Lian_Yunlong)\
**Replies:** 4\
**Last updated:** [July 23, 2022, 4:15am UTC](https://discourse.julialang.org/t/linearalgebra-breaks-cuarray/84570 "2022-07-23T04:15:29Z")

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Hi, I have made a minimal reproducible example on the errors reported in my previous posts. It seems to me that the A / b operation breaks sonething in the CuArray, which is obscure to the user. Mysterious as it is, t…

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## [Yticks on Makie plots get on top of the legend box](https://discourse.julialang.org/t/yticks-on-makie-plots-get-on-top-of-the-legend-box/84633)

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**Author:** [@RayleighLord](https://discourse.julialang.org/u/RayleighLord)\
**Replies:** 5\
**Last updated:** [July 22, 2022, 7:42pm UTC](https://discourse.julialang.org/t/yticks-on-makie-plots-get-on-top-of-the-legend-box/84633 "2022-07-22T19:42:54Z")

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Hello, Using a customized set of attributes for my plots, I found that the yticks can appear on top of a legend box. For me, this behaviour is highly undesirable but I have not found a way to make the legend box appear …

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## [Graph computing benchmarks: comparing the scalability of Dask, Dagger.jl, Tensorflow and Julius](https://discourse.julialang.org/t/graph-computing-benchmarks-comparing-the-scalability-of-dask-dagger-jl-tensorflow-and-julius/80745)

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**Author:** [@Yadong\_Li](https://discourse.julialang.org/u/Yadong_Li)\
**Replies:** 6\
**Last updated:** [July 22, 2022, 3:29pm UTC](https://discourse.julialang.org/t/graph-computing-benchmarks-comparing-the-scalability-of-dask-dagger-jl-tensorflow-and-julius/80745 "2022-07-22T15:29:55Z")

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Graph computing solutions like Dask/Dagger.jl are gaining popularity among developers, mainly because of their easy built-in distribution capabilities. If you are considering one of these graph computing solutions for yo…

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## [Complex filtering of DataFrame](https://discourse.julialang.org/t/complex-filtering-of-dataframe/78650)

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**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 9\
**Last updated:** [July 22, 2022, 1:48pm UTC](https://discourse.julialang.org/t/complex-filtering-of-dataframe/78650 "2022-07-22T13:48:37Z")

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I have this data frame that I want to filter: using DataFrames using StatsBase df = DataFrame(id = repeat(sample(1:1000, 100; replace=false), inner=2), s = repeat(1:2, inner=1, outer=100)) insertcols!(df, :t =\> rand(2:…

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## [Seeking assistance to INSERT data into Postgres DB using LibPQ.jl](https://discourse.julialang.org/t/seeking-assistance-to-insert-data-into-postgres-db-using-libpq-jl/84510)

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**Author:** [@adenoz](https://discourse.julialang.org/u/adenoz)\
**Replies:** 5\
**Last updated:** [July 22, 2022, 4:26am UTC](https://discourse.julialang.org/t/seeking-assistance-to-insert-data-into-postgres-db-using-libpq-jl/84510 "2022-07-22T04:26:22Z")

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Hi, Firstly, I am still learning Julia and my recent attempts to expand into Julia is through testing how to write data into a PostgreSQL database. I have been able to successfully connect to and query data in a PG data…

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## [ReinforcementLearning.jl weird behavior on custom environment, reset! is in Schrödingers namespace](https://discourse.julialang.org/t/reinforcementlearning-jl-weird-behavior-on-custom-environment-reset-is-in-schrodingers-namespace/84605)

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**Author:** [@bileamScheuvens](https://discourse.julialang.org/u/bileamScheuvens)\
**Replies:** 0\
**Last updated:** [July 21, 2022, 8:43pm UTC](https://discourse.julialang.org/t/reinforcementlearning-jl-weird-behavior-on-custom-environment-reset-is-in-schrodingers-namespace/84605 "2022-07-21T20:43:19Z")

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After implementing the RLBase.reset! method for my environment im being told the method doesn’t exist. When checking in help mode, Julia asks whether i meant ‘reset!’ instead of ‘reset!’. Does anyone have a clue where …

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## [Pass information between optimization iteration](https://discourse.julialang.org/t/pass-information-between-optimization-iteration/84598)

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**Author:** [@emurrayl](https://discourse.julialang.org/u/emurrayl)\
**Replies:** 2\
**Last updated:** [July 21, 2022, 7:06pm UTC](https://discourse.julialang.org/t/pass-information-between-optimization-iteration/84598 "2022-07-21T19:06:32Z")

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Hi everyone, I am trying to optimize a likelihood function. However, for each guess of the parameter value, I need to solve a value function iteration (VFI) problem to compute the likelihood. To speed up the process, I …

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## [Sensitivity of a SDE w.r.t tspan](https://discourse.julialang.org/t/sensitivity-of-a-sde-w-r-t-tspan/83998)

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**Author:** [@stochasticguy](https://discourse.julialang.org/u/stochasticguy)\
**Replies:** 3\
**Last updated:** [July 21, 2022, 3:51pm UTC](https://discourse.julialang.org/t/sensitivity-of-a-sde-w-r-t-tspan/83998 "2022-07-21T15:51:44Z")

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Hi all, I’m using SciMLSensitivity.jl to get the sensitivities of the transformation defined by: f(S\_T) = exp(- r \* T) \* max(S(T) - K, 0.0), where S\_T is the solution at time T of a SDE system of the form: dS\_t = \\mu…

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## [RandomForestRegressor in Julia](https://discourse.julialang.org/t/randomforestregressor-in-julia/84425)

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**Author:** [@Shayan](https://discourse.julialang.org/u/Shayan)\
**Replies:** 9\
**Last updated:** [July 21, 2022, 3:30pm UTC](https://discourse.julialang.org/t/randomforestregressor-in-julia/84425 "2022-07-21T15:30:53Z")

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I’m trying to train a RandomForestRegressor using DecisionTree.jl and RandomizedSearchCV (contained in ScikitLearn.jl) in Julia. Primary datasets like x\_train and y\_train etc. are provided in my google drive as well, So…

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## [Share colormap for Plotly Stacked Heatmaps](https://discourse.julialang.org/t/share-colormap-for-plotly-stacked-heatmaps/84547)

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**Author:** [@KaiserDan37](https://discourse.julialang.org/u/KaiserDan37)\
**Replies:** 2\
**Last updated:** [July 21, 2022, 1:39pm UTC](https://discourse.julialang.org/t/share-colormap-for-plotly-stacked-heatmaps/84547 "2022-07-21T13:39:21Z")

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Hello everyone, I am creating a faceted plot using the Plotly backend and and having trouble with stacking subplots of heatmaps. Specifically, the colorbars appear to overlap and I would prefer if they shared a single c…

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## [Error accessing elements within constraint matrix](https://discourse.julialang.org/t/error-accessing-elements-within-constraint-matrix/84565)

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**Author:** [@brett\_d](https://discourse.julialang.org/u/brett_d)\
**Replies:** 2\
**Last updated:** [July 21, 2022, 10:55am UTC](https://discourse.julialang.org/t/error-accessing-elements-within-constraint-matrix/84565 "2022-07-21T10:55:54Z")

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I am trying to write a constraint that sums the process times for each row of a matrix, Z\[a,p\] where Z is a binary decision variable = 1 if a is assigned p; = 0 otherwise. I am trying to multiply the 1’s in the row by t…

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## [Calculate the number of values greater than a certain value](https://discourse.julialang.org/t/calculate-the-number-of-values-greater-than-a-certain-value/84578)

<div class="topic-metadata">

**Author:** [@chenr86](https://discourse.julialang.org/u/chenr86)\
**Replies:** 2\
**Last updated:** [July 21, 2022, 7:57am UTC](https://discourse.julialang.org/t/calculate-the-number-of-values-greater-than-a-certain-value/84578 "2022-07-21T07:57:36Z")

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Hello, I’m solving a MINLP problem. In my case, there is an objective function max(sum(time60\[time\_slice\])) indicating the number of time slices in which the expression Q\[time\_slice\] is greater than 60. That is to say: …

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## [Performance of PencilFFTs with CuArray](https://discourse.julialang.org/t/performance-of-pencilffts-with-cuarray/84569)

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**Author:** [@Lightup1](https://discourse.julialang.org/u/Lightup1)\
**Replies:** 1\
**Last updated:** [July 21, 2022, 6:49am UTC](https://discourse.julialang.org/t/performance-of-pencilffts-with-cuarray/84569 "2022-07-21T06:49:54Z")

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Performance issue on PencilFFTs with CuArray CuArray Performance · Issue #56 · jipolanco/PencilFFTs.jl (github.com) Post here to find more tests. Code example: CUFFT: using CUDA using FFTW using BenchmarkTools prin…

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## [Max Plus Method for Joint Action Selection: Use-Case and Implementation](https://discourse.julialang.org/t/max-plus-method-for-joint-action-selection-use-case-and-implementation/71847)

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**Author:** [@YummyPampers2](https://discourse.julialang.org/u/YummyPampers2)\
**Replies:** 1\
**Last updated:** [July 21, 2022, 12:42am UTC](https://discourse.julialang.org/t/max-plus-method-for-joint-action-selection-use-case-and-implementation/71847 "2022-07-21T00:42:32Z")

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Good Day Folks: Could anyone point me towards a successful implementation (or proxy) of the Max-Plus method for joint selection? If not are there any Markov Decision Process (MDP) or multi-agent Markov decision proce…

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## [Cuda-memcheck reports over 1300 errors with 4 lines of julia code with CUDA.jl](https://discourse.julialang.org/t/cuda-memcheck-reports-over-1300-errors-with-4-lines-of-julia-code-with-cuda-jl/84516)

<div class="topic-metadata">

**Author:** [@Lian\_Yunlong](https://discourse.julialang.org/u/Lian_Yunlong)\
**Replies:** 2\
**Last updated:** [July 20, 2022, 11:39pm UTC](https://discourse.julialang.org/t/cuda-memcheck-reports-over-1300-errors-with-4-lines-of-julia-code-with-cuda-jl/84516 "2022-07-20T23:39:00Z")

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I have a file test.jl of four lines of Julia code using CUDA A = CuArray(rand(1000,1000)); B = CuArray(rand(1000,1000)); C = A \* B; After running the command cuda-memcheck julia test.jl \>\> test.jl.log I have got so m…

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