# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=136

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**Page:** 137

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## [Crystal Graphs w/ GeometricFlux.jl](https://discourse.julialang.org/t/crystal-graphs-w-geometricflux-jl/109773)

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**Author:** [@Stefan\_Bringuier](https://discourse.julialang.org/u/Stefan_Bringuier)\
**Replies:** 0\
**Last updated:** [February 6, 2024, 12:25am UTC](https://discourse.julialang.org/t/crystal-graphs-w-geometricflux-jl/109773 "2024-02-06T00:25:40Z")

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I’m fairly new to GeometricFlux.jl and working on trying to implement the Crystal Graph CNN approach by Xie and Grossman. I have the following FeaturedGraph, target pair dataset. I guess what I’m wondering is 1.) How sho…

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## [Supporting SIMD-enabled objective functions in optimization APIs](https://discourse.julialang.org/t/supporting-simd-enabled-objective-functions-in-optimization-apis/109728)

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**Author:** [@nielsls](https://discourse.julialang.org/u/nielsls)\
**Replies:** 3\
**Last updated:** [February 5, 2024, 8:22pm UTC](https://discourse.julialang.org/t/supporting-simd-enabled-objective-functions-in-optimization-apis/109728 "2024-02-05T20:22:32Z")

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With SIMD the CPU may execute the same instructions on e.g. 4x differents datasets just as fast as on 1x dataset. Assuming the user has a SIMD-enabled objective function - are there optimization algos that can exploit t…

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## [Help with column generation implementation](https://discourse.julialang.org/t/help-with-column-generation-implementation/109737)

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**Author:** [@Carl\_Baier](https://discourse.julialang.org/u/Carl_Baier)\
**Replies:** 1\
**Last updated:** [February 5, 2024, 8:12pm UTC](https://discourse.julialang.org/t/help-with-column-generation-implementation/109737 "2024-02-05T20:12:29Z")

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Hello, i am currently working on a column generation model which i would like to solve with gurobi in Julia. As i am a total newbie, i dont really know where to start. This is the model i would like to implement.PDF Thi…

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## [Scaling up a Dash.jl application?](https://discourse.julialang.org/t/scaling-up-a-dash-jl-application/109660)

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**Author:** [@JesperMartinsson](https://discourse.julialang.org/u/JesperMartinsson)\
**Replies:** 2\
**Last updated:** [February 5, 2024, 7:29pm UTC](https://discourse.julialang.org/t/scaling-up-a-dash-jl-application/109660 "2024-02-05T19:29:26Z")

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I’m running a Dash.jl application simply as: run\_server(app, "0.0.0.0", 8081) Is it possible to scale it up easily (e.g. by adding more threads)?

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## [How to insert columns in sub-tables for a grouped dataframe in \`DataFrames.jl\`?](https://discourse.julialang.org/t/how-to-insert-columns-in-sub-tables-for-a-grouped-dataframe-in-dataframes-jl/109713)

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**Author:** [@anon56682678](https://discourse.julialang.org/u/anon56682678)\
**Replies:** 4\
**Last updated:** [February 5, 2024, 6:49pm UTC](https://discourse.julialang.org/t/how-to-insert-columns-in-sub-tables-for-a-grouped-dataframe-in-dataframes-jl/109713 "2024-02-05T18:49:54Z")

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What I want to do is: Group a data-frame by column (“col1”) in DataFrames.jl, call it grouped\_df Send the sub-tables from the grouped\_df to a user defined function The user-defined function will transform an exis…

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## [Help with WeakStringRef when inserting into database](https://discourse.julialang.org/t/help-with-weakstringref-when-inserting-into-database/109744)

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**Author:** [@rdavis120](https://discourse.julialang.org/u/rdavis120)\
**Replies:** 0\
**Last updated:** [February 5, 2024, 3:36pm UTC](https://discourse.julialang.org/t/help-with-weakstringref-when-inserting-into-database/109744 "2024-02-05T15:36:11Z")

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The duckdb appender api has a line of non-working code to convert a WeakStringRef types to be inserted into the database as a type Varchar. I have never used the WeakStringRef type so I do not know how this conversion sh…

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## [Lux (And Flux), "parallel" Network Input. When Input is flat, Zygote gradient works, when input is not flat it doesn't](https://discourse.julialang.org/t/lux-and-flux-parallel-network-input-when-input-is-flat-zygote-gradient-works-when-input-is-not-flat-it-doesnt/107763)

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**Author:** [@Qfl3x](https://discourse.julialang.org/u/Qfl3x)\
**Replies:** 10\
**Last updated:** [February 5, 2024, 6:10pm UTC](https://discourse.julialang.org/t/lux-and-flux-parallel-network-input-when-input-is-flat-zygote-gradient-works-when-input-is-not-flat-it-doesnt/107763 "2024-02-05T18:10:42Z")

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It’s easier to see the code: using Lux using Zygote using ComponentArrays using Random x\_test\_flat = rand(16) x\_test\_p = \[rand(4) for \_ in 1:4\] NNmodel\_1 = Lux.Chain(Lux.Dense(16 =\> 18, sigmoid), …

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## [Model a first-order-plus-delay system in ModelingToolkit](https://discourse.julialang.org/t/model-a-first-order-plus-delay-system-in-modelingtoolkit/109695)

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**Author:** [@VPBML](https://discourse.julialang.org/u/VPBML)\
**Replies:** 11\
**Last updated:** [February 5, 2024, 5:34pm UTC](https://discourse.julialang.org/t/model-a-first-order-plus-delay-system-in-modelingtoolkit/109695 "2024-02-05T17:34:35Z")

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Hi, I wonder if there is any straightforward way to model a system consisting of a first-order-plus-delay plant T(s) = K.exp(-delay.s)/(tau.s + 1) and a PI controller using components from ModelingToolkitStandardLibrary…

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## [Symbolics build\_function issues on complicated expressions](https://discourse.julialang.org/t/symbolics-build-function-issues-on-complicated-expressions/109727)

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**Author:** [@Johan-Gronqvist](https://discourse.julialang.org/u/Johan-Gronqvist)\
**Replies:** 6\
**Last updated:** [February 5, 2024, 4:48pm UTC](https://discourse.julialang.org/t/symbolics-build-function-issues-on-complicated-expressions/109727 "2024-02-05T16:48:13Z")

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I am trying to use Symbolics to define and manipulate my problem before moving to numerical methods to actually solve my problem. After initial manipulations, I want to replace all symbolic variables with their actual v…

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## [Raw"\\nabla" fails in labels](https://discourse.julialang.org/t/raw-nabla-fails-in-labels/109739)

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**Author:** [@blob](https://discourse.julialang.org/u/blob)\
**Replies:** 2\
**Last updated:** [February 5, 2024, 3:09pm UTC](https://discourse.julialang.org/t/raw-nabla-fails-in-labels/109739 "2024-02-05T15:09:49Z")

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I am trying to get “nice” labels for a plot and the unicode characters work properly only sometimes: using Plots plot(rand(10),label="δ works") plot!(rand(10),label=raw"\\delta works") …

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## [Parser for safetensors](https://discourse.julialang.org/t/parser-for-safetensors/109366)

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**Author:** [@Tomas\_Pevny](https://discourse.julialang.org/u/Tomas_Pevny)\
**Replies:** 6\
**Last updated:** [February 5, 2024, 12:35pm UTC](https://discourse.julialang.org/t/parser-for-safetensors/109366 "2024-02-05T12:35:15Z")

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There is a new format to store weights of neural networks advocated by huggingface, called safetensors. I have encountered when I wanted to download phi-2 model to Transformers.jl (see this pull request Add Phi model by…

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## [Converting UK National Grid to Lat Lon and vice versa](https://discourse.julialang.org/t/converting-uk-national-grid-to-lat-lon-and-vice-versa/109628)

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**Author:** [@TimG](https://discourse.julialang.org/u/TimG)\
**Replies:** 17\
**Last updated:** [February 5, 2024, 9:59am UTC](https://discourse.julialang.org/t/converting-uk-national-grid-to-lat-lon-and-vice-versa/109628 "2024-02-05T09:59:43Z")

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Just getting started on what I expect to be a long learning curve with maps (no prior experience). I have a UK postcode picked more or less at random: BT3 9DT. Google tells me this has the following properties: Latitu…

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## [Stop Criteria using JuMP with HiGHS when find the first feasible solution](https://discourse.julialang.org/t/stop-criteria-using-jump-with-highs-when-find-the-first-feasible-solution/109520)

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**Author:** [@grem](https://discourse.julialang.org/u/grem)\
**Replies:** 4\
**Last updated:** [February 5, 2024, 9:12am UTC](https://discourse.julialang.org/t/stop-criteria-using-jump-with-highs-when-find-the-first-feasible-solution/109520 "2024-02-05T09:12:16Z")

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Hello, I have a MILP problem, which is feasible, and I would like to stop the model run when the solver find the first feasible solution. Is it possible to use a stop criteria like that? I can only find one about time…

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## [Get x and y limits of Makie plot](https://discourse.julialang.org/t/get-x-and-y-limits-of-makie-plot/109716)

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**Author:** [@jar1](https://discourse.julialang.org/u/jar1)\
**Replies:** 5\
**Last updated:** [February 5, 2024, 7:40am UTC](https://discourse.julialang.org/t/get-x-and-y-limits-of-makie-plot/109716 "2024-02-05T07:40:16Z")

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How to get axis limits? scatter(50randn(5), 50randn(5))

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## [Correct way to save Makie plot to IOBuffer](https://discourse.julialang.org/t/correct-way-to-save-makie-plot-to-iobuffer/87793)

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**Author:** [@contradict](https://discourse.julialang.org/u/contradict)\
**Replies:** 6\
**Last updated:** [February 5, 2024, 6:41am UTC](https://discourse.julialang.org/t/correct-way-to-save-makie-plot-to-iobuffer/87793 "2024-02-05T06:41:06Z")

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I am generating a web page including a data URL for a Makie plot. I would like to avoid saving the plot to a file if possible. I figured this out but I would like to know if there is a better way. using Makie, CairoMaki…

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## [Plotting to multiple separate figures](https://discourse.julialang.org/t/plotting-to-multiple-separate-figures/109681)

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**Author:** [@cbarring](https://discourse.julialang.org/u/cbarring)\
**Replies:** 5\
**Last updated:** [February 5, 2024, 1:54am UTC](https://discourse.julialang.org/t/plotting-to-multiple-separate-figures/109681 "2024-02-05T01:54:34Z")

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Hi. I would like to generate 2 separate figures. These are shown below. Figure 1 shows the numerical solution, plus the actual solution. Figure 2 shows the (tiny) error. I can’t put all this on a single plot since t…

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## [Optimization constraints](https://discourse.julialang.org/t/optimization-constraints/109653)

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**Author:** [@Lemma](https://discourse.julialang.org/u/Lemma)\
**Replies:** 7\
**Last updated:** [February 4, 2024, 11:49pm UTC](https://discourse.julialang.org/t/optimization-constraints/109653 "2024-02-04T23:49:07Z")

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I’m working on an optimization model in JuMP where I need to implement conditional constraints based on the sign of the right-hand side (RHS) of certain conditions. This is typically handled using the Big-M method, which…

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## [Survey of Non-Linear Optimization Modeling Layers in Julia](https://discourse.julialang.org/t/survey-of-non-linear-optimization-modeling-layers-in-julia/78168)

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**Author:** [@ccoffrin](https://discourse.julialang.org/u/ccoffrin)\
**Replies:** 63\
**Last updated:** [February 4, 2024, 10:34pm UTC](https://discourse.julialang.org/t/survey-of-non-linear-optimization-modeling-layers-in-julia/78168 "2024-02-04T22:34:44Z")

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I am doing a survey of the NLP modeling layers in Julia to see which might be applicable to the kinds of problems that I regularly solve. I have the following basic requirements of the modeling layer, Support for non-…

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## [Oceananigans.jl](https://discourse.julialang.org/t/oceananigans-jl/109693)

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**Author:** [@benslinux](https://discourse.julialang.org/u/benslinux)\
**Replies:** 0\
**Last updated:** [February 4, 2024, 8:33am UTC](https://discourse.julialang.org/t/oceananigans-jl/109693 "2024-02-04T08:33:58Z")

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\*\* SOLVED - Tried running the demo program for Oceananigans - I got as far as this: julia\> run!(simulation) \[ Info: Initializing simulation… \[ Info: … simulation initialization complete (88.034 ms) \[ Info: Execu…

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## [How can I read a GDAL dataset from an io stream?](https://discourse.julialang.org/t/how-can-i-read-a-gdal-dataset-from-an-io-stream/109679)

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**Author:** [@maxfreu](https://discourse.julialang.org/u/maxfreu)\
**Replies:** 2\
**Last updated:** [February 4, 2024, 12:14pm UTC](https://discourse.julialang.org/t/how-can-i-read-a-gdal-dataset-from-an-io-stream/109679 "2024-02-04T12:14:37Z")

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Hi! I’m wondering how I can read a gdal dataset that comes in the form of some io stream. Imagine you iterate over a tar file of tifs via TarIterator. For each tif there is an io stream containing the raw dataset data as…

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## [Memoization in mcmc](https://discourse.julialang.org/t/memoization-in-mcmc/109694)

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**Author:** [@swsw](https://discourse.julialang.org/u/swsw)\
**Replies:** 0\
**Last updated:** [February 4, 2024, 9:13am UTC](https://discourse.julialang.org/t/memoization-in-mcmc/109694 "2024-02-04T09:13:04Z")

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Hi there, I wondered if how Turing or RxInfer deals w/ the following situation. For example, I have 10 parameters x1,…x10, the likelihood function is as follows. x1^2 + … + x10^2 Apparently, when updating x1, the o…

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## [Are database connection pools typically used with concurrency](https://discourse.julialang.org/t/are-database-connection-pools-typically-used-with-concurrency/109689)

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**Author:** [@rdavis120](https://discourse.julialang.org/u/rdavis120)\
**Replies:** 2\
**Last updated:** [February 4, 2024, 3:44am UTC](https://discourse.julialang.org/t/are-database-connection-pools-typically-used-with-concurrency/109689 "2024-02-04T03:44:10Z")

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When creating hundreds of tasks using @spawn (with multiple threads), where each task has a connection to an embedded database, is it necessary to use a connection pool structure or can each task maintain its own DBInter…

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## [How to create a new axis in a loop using CairoMakie?](https://discourse.julialang.org/t/how-to-create-a-new-axis-in-a-loop-using-cairomakie/109623)

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**Author:** [@albrightand](https://discourse.julialang.org/u/albrightand)\
**Replies:** 4\
**Last updated:** [February 4, 2024, 2:59am UTC](https://discourse.julialang.org/t/how-to-create-a-new-axis-in-a-loop-using-cairomakie/109623 "2024-02-04T02:59:37Z")

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I’m trying to create a series of histograms by looping through a data frame and plotting each entry as a histogram. There is 20 different plots, so it would be inconvenient to not use a loop. In the Makie docs, it shows…

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## [How to implement a filtered derivative](https://discourse.julialang.org/t/how-to-implement-a-filtered-derivative/109441)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 29\
**Last updated:** [February 3, 2024, 10:51pm UTC](https://discourse.julialang.org/t/how-to-implement-a-filtered-derivative/109441 "2024-02-03T22:51:18Z")

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How can I implement a filtered, discrete time derivative following the equations: u\_1 = u − y\_1 dy\_1/dt = (1 / T\_D) \* u\_1 y = (K\_D / T\_D) \* u\_1 filtertau = 0.01 as described on page 128 of the following document: http…

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## [3D surfaces + time slider](https://discourse.julialang.org/t/3d-surfaces-time-slider/109673)

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**Author:** [@sob](https://discourse.julialang.org/u/sob)\
**Replies:** 2\
**Last updated:** [February 3, 2024, 5:49pm UTC](https://discourse.julialang.org/t/3d-surfaces-time-slider/109673 "2024-02-03T17:49:45Z")

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Hi, PlotlyJS provides the following code to represent multiple surfaces at once (see multiple surfaces): julia\> using PlotlyJS julia\> function multiple\_surface() z1 = Vector\[\[8.83, 8.89, 8.81, 8.87, 8.9, 8.…

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## [3D plot labels customization](https://discourse.julialang.org/t/3d-plot-labels-customization/109675)

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**Author:** [@Maucejo](https://discourse.julialang.org/u/Maucejo)\
**Replies:** 0\
**Last updated:** [February 3, 2024, 4:44pm UTC](https://discourse.julialang.org/t/3d-plot-labels-customization/109675 "2024-02-03T16:44:02Z")

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Hi all, I am using Makie.jl as my main plotting library. Maybe I missed something in the doc, but I don’t know if it is possible to customize the ticks and axis labels layout of Axis3 to get something like in the figure …

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## [Integration of functions over geometries](https://discourse.julialang.org/t/integration-of-functions-over-geometries/81994)

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**Author:** [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Replies:** 30\
**Last updated:** [February 3, 2024, 4:07pm UTC](https://discourse.julialang.org/t/integration-of-functions-over-geometries/81994 "2024-02-03T16:07:20Z")

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Cross-posting from Zulip’s #meshes.jl channel… Does anyone know of a good reference for integration rules over different geometries? For example, to integrate a function f over a triangle, we can consider the surface i…

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## [KeyError in PowerModels](https://discourse.julialang.org/t/keyerror-in-powermodels/109656)

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**Author:** [@Rasoul](https://discourse.julialang.org/u/Rasoul)\
**Replies:** 3\
**Last updated:** [February 3, 2024, 6:16am UTC](https://discourse.julialang.org/t/keyerror-in-powermodels/109656 "2024-02-03T06:16:20Z")

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Hi All, I developed PowerModels and PowerModelsAnnex, then ran my customized code in PowerModelsAnnex and encountered the following error. Could you please provide guidance on how to resolve this? Thanks in advance! "E…

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## [BatchIntegralFunction not appearing to work as intended](https://discourse.julialang.org/t/batchintegralfunction-not-appearing-to-work-as-intended/109513)

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**Author:** [@HSnowden](https://discourse.julialang.org/u/HSnowden)\
**Replies:** 2\
**Last updated:** [February 3, 2024, 4:05am UTC](https://discourse.julialang.org/t/batchintegralfunction-not-appearing-to-work-as-intended/109513 "2024-02-03T04:05:09Z")

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I am trying to implement a batch integral function using the new BatchIntegralFunction rather than then deprecated nout/batch keywords. However, when I do, the in-place vector to fill place the answer in is the incorrec…

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## [Physics-informed training of a surrogate model involving finite element analysis](https://discourse.julialang.org/t/physics-informed-training-of-a-surrogate-model-involving-finite-element-analysis/103735)

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**Author:** [@touste](https://discourse.julialang.org/u/touste)\
**Replies:** 4\
**Last updated:** [February 2, 2024, 10:29pm UTC](https://discourse.julialang.org/t/physics-informed-training-of-a-surrogate-model-involving-finite-element-analysis/103735 "2024-02-02T22:29:53Z")

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Hi all, I’m looking at ways to accelerate mechanical simulations for endovascular applications. We published a paper recently where we present EndoBeams.jl, a finite element framework for beam elements in contact with a…

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