# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=76

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**Page:** 77

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## [BifurcationKit.jl: Continuation of non-autonomous ODE limit cycle](https://discourse.julialang.org/t/bifurcationkit-jl-continuation-of-non-autonomous-ode-limit-cycle/121871)

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**Author:** [@mjowen](https://discourse.julialang.org/u/mjowen)\
**Replies:** 0\
**Last updated:** [October 28, 2024, 2:40pm UTC](https://discourse.julialang.org/t/bifurcationkit-jl-continuation-of-non-autonomous-ode-limit-cycle/121871 "2024-10-28T14:40:33Z")

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Hi, I have a non-autonomous periodic ODE system and I want to use BifurcationKit to run continuation on the limit cycle. The system features a periodic discontinuous forcing function I\_St. I have followed the steps here …

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## [Enforce positivity in simple PDE solution](https://discourse.julialang.org/t/enforce-positivity-in-simple-pde-solution/121738)

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**Author:** [@ify](https://discourse.julialang.org/u/ify)\
**Replies:** 5\
**Last updated:** [October 28, 2024, 10:35am UTC](https://discourse.julialang.org/t/enforce-positivity-in-simple-pde-solution/121738 "2024-10-28T10:35:57Z")

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Hi all, Pretty new to julia. I am trying to solve a simplified PDE that I normally would do in R. In R, the numerical steady state solution can be constrained to obtain solution concentration. However, when I translate …

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## [Using StaticArrays with EnsembleAnalysis runs with SDEProblem but not ODEProblem](https://discourse.julialang.org/t/using-staticarrays-with-ensembleanalysis-runs-with-sdeproblem-but-not-odeproblem/121837)

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**Author:** [@gjgress](https://discourse.julialang.org/u/gjgress)\
**Replies:** 2\
**Last updated:** [October 28, 2024, 10:11am UTC](https://discourse.julialang.org/t/using-staticarrays-with-ensembleanalysis-runs-with-sdeproblem-but-not-odeproblem/121837 "2024-10-28T10:11:26Z")

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Context: In my personal project I am working with running ensemble problems of SDEs. To improve performance, I used SVectors wherever possible. Depending on my needs, I used componentwise\_vectors\_timepoint to interpolat…

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## [Help with Multi-GPU FDTD implementation: halo exchange and efficient monitors](https://discourse.julialang.org/t/help-with-multi-gpu-fdtd-implementation-halo-exchange-and-efficient-monitors/121676)

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**Author:** [@lucasgrjn](https://discourse.julialang.org/u/lucasgrjn)\
**Replies:** 1\
**Last updated:** [October 28, 2024, 9:05am UTC](https://discourse.julialang.org/t/help-with-multi-gpu-fdtd-implementation-halo-exchange-and-efficient-monitors/121676 "2024-10-28T09:05:50Z")

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Hi everyone! I am a physicist and photonics engineer. Recently, Meta released a Julia package called Khronos to perform FDTD (Finite-Difference Time-Domain) simulations. The basic idea is to iteratively propagate light …

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## [Linear parameter varying control (LPV control)](https://discourse.julialang.org/t/linear-parameter-varying-control-lpv-control/121840)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 8\
**Last updated:** [October 28, 2024, 9:14am UTC](https://discourse.julialang.org/t/linear-parameter-varying-control-lpv-control/121840 "2024-10-28T09:14:30Z")

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I am trying to implement an LPV controller based on GitHub - JuliaControl/DiscretePIDs.jl: Discrete-time PID controllers in Julia The idea is easy: Use a controller for heading/ course with an inner and an outer loop. T…

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## [Plots.jl - Plot groups of data on different subplots](https://discourse.julialang.org/t/plots-jl-plot-groups-of-data-on-different-subplots/74477)

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**Author:** [@cripcate](https://discourse.julialang.org/u/cripcate)\
**Replies:** 8\
**Last updated:** [October 28, 2024, 8:47am UTC](https://discourse.julialang.org/t/plots-jl-plot-groups-of-data-on-different-subplots/74477 "2024-10-28T08:47:14Z")

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Consider this sample data: using DataFrames, Plots, Random sample\_data = DataFrame(\[rand(10), sample(\['A', 'B', 'C'\], 10)\], \["value", "group"\]) 10×2 DataFrame Row │ value group │ Float64 Char ─────┼────…

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## [Quantitative Finance in Julia](https://discourse.julialang.org/t/quantitative-finance-in-julia/119734)

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**Author:** [@Pascal\_Buhler](https://discourse.julialang.org/u/Pascal_Buhler)\
**Replies:** 20\
**Last updated:** [October 28, 2024, 7:20am UTC](https://discourse.julialang.org/t/quantitative-finance-in-julia/119734 "2024-10-28T07:20:18Z")

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Could we add in Market Data, also API from SWX / SIX or Marketscreener / Google etc? just in case something went wrong?

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## [Balanced clustering or assignment of 3D points in space](https://discourse.julialang.org/t/balanced-clustering-or-assignment-of-3d-points-in-space/121192)

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**Author:** [@BambOoxX](https://discourse.julialang.org/u/BambOoxX)\
**Replies:** 15\
**Last updated:** [October 27, 2024, 10:08am UTC](https://discourse.julialang.org/t/balanced-clustering-or-assignment-of-3d-points-in-space/121192 "2024-10-27T10:08:37Z")

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I’m currently trying to solve the following problem Let P be a set of points in 3D space Split P into smaller sets of approximately equal size, the maximum size being a hard constraint Some properties about P P is g…

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## [Avoid allocation of a Flux model on the CPU](https://discourse.julialang.org/t/avoid-allocation-of-a-flux-model-on-the-cpu/121785)

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**Author:** [@mesonepigreco](https://discourse.julialang.org/u/mesonepigreco)\
**Replies:** 3\
**Last updated:** [October 27, 2024, 8:12am UTC](https://discourse.julialang.org/t/avoid-allocation-of-a-flux-model-on-the-cpu/121785 "2024-10-27T08:12:19Z")

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Hi everyone, I have to execute a flux model inside a Monte Carlo simulation. I am currently working on the CPU; I am facing the problem of executing a model(configuration)for each step of the Monte Carlo, which allocate…

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## [StochasticDelayDiffEq having trouble with stiff models \[solved\]](https://discourse.julialang.org/t/stochasticdelaydiffeq-having-trouble-with-stiff-models-solved/121725)

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**Author:** [@kmd](https://discourse.julialang.org/u/kmd)\
**Replies:** 2\
**Last updated:** [October 26, 2024, 7:58pm UTC](https://discourse.julialang.org/t/stochasticdelaydiffeq-having-trouble-with-stiff-models-solved/121725 "2024-10-26T19:58:14Z")

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I am using SciML to try to integrate a stiff model with small noise. It is giving me tons of grief though, and I am not sure how to approach it. I even tried setting tolerances to very small values & increasing maxiter…

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## [Screening Interest in a unified Vector/Raster Package, akin to R Terra](https://discourse.julialang.org/t/screening-interest-in-a-unified-vector-raster-package-akin-to-r-terra/121613)

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**Author:** [@souma](https://discourse.julialang.org/u/souma)\
**Replies:** 27\
**Last updated:** [October 26, 2024, 1:36pm UTC](https://discourse.julialang.org/t/screening-interest-in-a-unified-vector-raster-package-akin-to-r-terra/121613 "2024-10-26T13:36:33Z")

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Hello all, I haven’t been active in Discourse but I’ve been working with Julia for scientific computing for quite a few years at this point. I want to know what the interest is in a JuliaGeo project/effort to harmonize…

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## [Simple optimizer?](https://discourse.julialang.org/t/simple-optimizer/121744)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 11\
**Last updated:** [October 25, 2024, 9:54pm UTC](https://discourse.julialang.org/t/simple-optimizer/121744 "2024-10-25T21:54:48Z")

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I have the following equation: res = c1 \* v\_app \* u\_s + c2/v\_app \* sin(psi) \* cos(beta) - psi\_dot and I want to determine the constants c1 and c2 based on measurements such that the the sum of res² over all measurement…

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## [Small integer programming problem](https://discourse.julialang.org/t/small-integer-programming-problem/121647)

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**Author:** [@StefanKarpinski](https://discourse.julialang.org/u/StefanKarpinski)\
**Replies:** 27\
**Last updated:** [October 25, 2024, 5:49pm UTC](https://discourse.julialang.org/t/small-integer-programming-problem/121647 "2024-10-25T17:49:58Z")

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I have a seemingly simple integer programming problem that I need a hard-coded algorithm for. Having this would help solve an issue in base Julia—interpreting floating point ranges fully correctly, if you can believe it.…

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## [Makie control heatmaps of volumeslices](https://discourse.julialang.org/t/makie-control-heatmaps-of-volumeslices/121696)

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**Author:** [@trasor](https://discourse.julialang.org/u/trasor)\
**Replies:** 2\
**Last updated:** [October 25, 2024, 6:43am UTC](https://discourse.julialang.org/t/makie-control-heatmaps-of-volumeslices/121696 "2024-10-25T06:43:36Z")

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Hello everyone. I try to use Makie to plot heatmap slices though a volume with their volumeslices functionality: volumeslices | Makie However, i am unable to control the positions or the numbers of the slices: using C…

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## [Calculating convex hulls through LP](https://discourse.julialang.org/t/calculating-convex-hulls-through-lp/121681)

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**Author:** [@joaoqcouto](https://discourse.julialang.org/u/joaoqcouto)\
**Replies:** 1\
**Last updated:** [October 24, 2024, 9:39pm UTC](https://discourse.julialang.org/t/calculating-convex-hulls-through-lp/121681 "2024-10-24T21:39:54Z")

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Hello, I am currently working on a problem in which I need to calculate multiple convex hulls for large datasets, as the following image shows: Two things to note: I don’t need adjacency information, simply knowing…

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## [\[ANN\] PairwiseMappingFormat.jl](https://discourse.julialang.org/t/ann-pairwisemappingformat-jl/121714)

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**Author:** [@jakobnissen](https://discourse.julialang.org/u/jakobnissen)\
**Replies:** 0\
**Last updated:** [October 24, 2024, 5:45pm UTC](https://discourse.julialang.org/t/ann-pairwisemappingformat-jl/121714 "2024-10-24T17:45:33Z")

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The newest BioJulia package has just been merged to the General Registry: PairwiseMappingFormat.jl. This package provide a parser for PAF (Pairwise mApping Format) files, which are used by some aligners such as minimap2…

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## [Eigvals of symmetric matrix](https://discourse.julialang.org/t/eigvals-of-symmetric-matrix/121672)

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**Author:** [@Daniel\_Scheinerman](https://discourse.julialang.org/u/Daniel_Scheinerman)\
**Replies:** 3\
**Last updated:** [October 24, 2024, 1:17pm UTC](https://discourse.julialang.org/t/eigvals-of-symmetric-matrix/121672 "2024-10-24T13:17:21Z")

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Within numpy in python there is the function np.linalg.eigvalsh which computes the eigenvalues of a hermetian matrix. It speeds up the computation of the eigenvalues when the matrix is symmetric. I just did a quick test …

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## [DBSCAN clustering with Haversine metric](https://discourse.julialang.org/t/dbscan-clustering-with-haversine-metric/121685)

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**Author:** [@miguelborrero](https://discourse.julialang.org/u/miguelborrero)\
**Replies:** 4\
**Last updated:** [October 24, 2024, 12:53pm UTC](https://discourse.julialang.org/t/dbscan-clustering-with-haversine-metric/121685 "2024-10-24T12:53:46Z")

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Hi there, I have an array of points (latitude, longitude) in radians and I am trying to use the package Clustering.jl to cluster my points. In the documentation it seems like a metric can be given, the default being: Eu…

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## [How to put gif or mp4 file in Literate documentation page?](https://discourse.julialang.org/t/how-to-put-gif-or-mp4-file-in-literate-documentation-page/121468)

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**Author:** [@vladdez](https://discourse.julialang.org/u/vladdez)\
**Replies:** 1\
**Last updated:** [October 24, 2024, 9:31am UTC](https://discourse.julialang.org/t/how-to-put-gif-or-mp4-file-in-literate-documentation-page/121468 "2024-10-24T09:31:12Z")

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I want to attach gif or mp4 file on documentation page. My code is: # \`\`\`@raw html # \<video autoplay loop muted playsinline controls src="../../../assets/topoplot\_animation\_UM.gif" /\> # \`\`\` This is the page deployed: B…

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## [Recommended workflow and packages for computing a slope along a tramway track](https://discourse.julialang.org/t/recommended-workflow-and-packages-for-computing-a-slope-along-a-tramway-track/119975)

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**Author:** [@zdenek\_hurak](https://discourse.julialang.org/u/zdenek_hurak)\
**Replies:** 39\
**Last updated:** [October 24, 2024, 9:00am UTC](https://discourse.julialang.org/t/recommended-workflow-and-packages-for-computing-a-slope-along-a-tramway-track/119975 "2024-10-24T09:00:37Z")

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I would like to ask for a recommendation on a workflow for computing a slope along a tramway track using Julia’s geo ecosystem (organizations JuliaEarth, JuliaGeo, …). The tramway tracks are obtained from OpenStreetMaps…

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## [Component-based model for N reactors connected to a tank](https://discourse.julialang.org/t/component-based-model-for-n-reactors-connected-to-a-tank/119536)

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**Author:** [@cstjean](https://discourse.julialang.org/u/cstjean)\
**Replies:** 9\
**Last updated:** [October 24, 2024, 8:29am UTC](https://discourse.julialang.org/t/component-based-model-for-n-reactors-connected-to-a-tank/119536 "2024-10-24T08:29:25Z")

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Say I’ve got 10 chemical reactors, which all flow into a single tank. The reactors all have different production rates for some species S. I’m interested in the concentration of S in the reactors and in the tank. I guess…

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## [How to override defaults with u0 in solve](https://discourse.julialang.org/t/how-to-override-defaults-with-u0-in-solve/121629)

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**Author:** [@Bart\_van\_de\_Lint](https://discourse.julialang.org/u/Bart_van_de_Lint)\
**Replies:** 2\
**Last updated:** [October 24, 2024, 5:02am UTC](https://discourse.julialang.org/t/how-to-override-defaults-with-u0-in-solve/121629 "2024-10-24T05:02:41Z")

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I have an ODEProblem with a system with default values, and with a starting state prob.u0. I want to be able to solve this problem from an arbitrary starting state u0 to the next timestep using solve(prob, QNDF(); save\_s…

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## [Sampling from a KDE object](https://discourse.julialang.org/t/sampling-from-a-kde-object/121604)

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**Author:** [@miguelborrero](https://discourse.julialang.org/u/miguelborrero)\
**Replies:** 4\
**Last updated:** [October 23, 2024, 8:54pm UTC](https://discourse.julialang.org/t/sampling-from-a-kde-object/121604 "2024-10-23T20:54:06Z")

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Hi there, I estimated the density for a variable of interest using the kde() function from KernelDensity.jl package. Is there not a built-in/efficient function that samples from this estimated density? Thanks a lot!

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## [Did i coded my pde correctly?](https://discourse.julialang.org/t/did-i-coded-my-pde-correctly/121661)

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**Author:** [@Shashi2\_Kumar](https://discourse.julialang.org/u/Shashi2_Kumar)\
**Replies:** 0\
**Last updated:** [October 23, 2024, 5:08pm UTC](https://discourse.julialang.org/t/did-i-coded-my-pde-correctly/121661 "2024-10-23T17:08:55Z")

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After many weeks of search for a pde solver for my elliptic pde i came across Julia. Found that it has a FNC package (FundamentalsNumericalComputation) that solves pde. I tried to encode my pde with boundary conditions a…

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## [Error returned from CUDA function in CUDA-aware MPI multi-GPU test](https://discourse.julialang.org/t/error-returned-from-cuda-function-in-cuda-aware-mpi-multi-gpu-test/121331)

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**Author:** [@luciano-drozda](https://discourse.julialang.org/u/luciano-drozda)\
**Replies:** 1\
**Last updated:** [October 23, 2024, 12:59pm UTC](https://discourse.julialang.org/t/error-returned-from-cuda-function-in-cuda-aware-mpi-multi-gpu-test/121331 "2024-10-23T12:59:45Z")

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Hi! I’m coming from this issue here, which seems to not relate to CUDA.jl specifically. Do you think it comes from my openmpi, cuda drivers installations ? Otherwise, could it come from MPI.jl ?

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## [Formating Dates.CompoundPeriod](https://discourse.julialang.org/t/formating-dates-compoundperiod/59167)

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**Author:** [@Laco\_Kovac](https://discourse.julialang.org/u/Laco_Kovac)\
**Replies:** 6\
**Last updated:** [October 23, 2024, 11:54am UTC](https://discourse.julialang.org/t/formating-dates-compoundperiod/59167 "2024-10-23T11:54:54Z")

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I have variable of type Dates.CompoundPeriod I need to change it to String in format HH:MM:SS (value will never exceed 1 hour) julia\> x = Dates.CompoundPeriod(Dates.Hour(12), Dates.Minute(13)) 12 hours, 13 minutes jul…

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## [Changing the size of VectorContinuousCallback](https://discourse.julialang.org/t/changing-the-size-of-vectorcontinuouscallback/119534)

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**Author:** [@evan-wehi](https://discourse.julialang.org/u/evan-wehi)\
**Replies:** 6\
**Last updated:** [October 23, 2024, 5:40am UTC](https://discourse.julialang.org/t/changing-the-size-of-vectorcontinuouscallback/119534 "2024-10-23T05:40:56Z")

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I’m modelling cell population dynamics. Cells die and divide so the size of system is always changing. I love DifferentialEquations.jl because it is the only library I know of that has an API for this. Most of my state v…

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## [Events seemingly ignored in system model](https://discourse.julialang.org/t/events-seemingly-ignored-in-system-model/121605)

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**Author:** [@jmaedler](https://discourse.julialang.org/u/jmaedler)\
**Replies:** 1\
**Last updated:** [October 22, 2024, 10:47pm UTC](https://discourse.julialang.org/t/events-seemingly-ignored-in-system-model/121605 "2024-10-22T22:47:34Z")

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Hi guys, I am running into an issue simulating a system model. Fundamentally it is two valves in sequence between two pressure sources. This is a test for the valve models which should allow these scenarios for a virtua…

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## [Timeseries model training using Lux.jl](https://discourse.julialang.org/t/timeseries-model-training-using-lux-jl/121618)

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**Author:** [@Rosejoycrocker](https://discourse.julialang.org/u/Rosejoycrocker)\
**Replies:** 0\
**Last updated:** [October 22, 2024, 10:36pm UTC](https://discourse.julialang.org/t/timeseries-model-training-using-lux-jl/121618 "2024-10-22T22:36:06Z")

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Hi, I’m using the Lux.jl simple LSTM classifier example ( Training a Simple LSTM | Lux.jl Docs ) to try and train a simple LSTM to predict timeseries data. I’m having issues however, as the LSTM model example is design…

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## [For TidierData.jl, wouldn't it make sense to introduce \`@sort\` etc along side \`@arrange\` given some verbs in dplyr were chosen due to "limitations" of R which aren't issues in Julia](https://discourse.julialang.org/t/for-tidierdata-jl-wouldnt-it-make-sense-to-introduce-sort-etc-along-side-arrange-given-some-verbs-in-dplyr-were-chosen-due-to-limitations-of-r-which-arent-issues-in-julia/121615)

<div class="topic-metadata">

**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 0\
**Last updated:** [October 22, 2024, 10:17pm UTC](https://discourse.julialang.org/t/for-tidierdata-jl-wouldnt-it-make-sense-to-introduce-sort-etc-along-side-arrange-given-some-verbs-in-dplyr-were-chosen-due-to-limitations-of-r-which-arent-issues-in-julia/121615 "2024-10-22T22:17:59Z")

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I was looking into the TidierData.jl api and I see familiar macro-verbs like @arrange which is basically @sort for all intents and purposes. So the question is why did dplyr choose arrange as the key word for sorting? I…

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