# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?page=312

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**Page:** 313

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## [Adomian polynomials](https://discourse.julialang.org/t/adomian-polynomials/74291)

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**Author:** [@sdwfrost](https://discourse.julialang.org/u/sdwfrost)\
**Replies:** 2\
**Last updated:** [January 10, 2022, 4:51am UTC](https://discourse.julialang.org/t/adomian-polynomials/74291 "2022-01-10T04:51:48Z")

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Hi Everyone, I’d like to solve some ODEs using Adomian decomposition (which opens up approaches to model distributed delays, etc.) for a repository of epidemiological models: https://github.com/epirecipes/sir-julia/issu…

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## [Application of Julia in Operation Research and Supply Chain](https://discourse.julialang.org/t/application-of-julia-in-operation-research-and-supply-chain/74300)

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**Author:** [@jaafar\_ballout](https://discourse.julialang.org/u/jaafar_ballout)\
**Replies:** 4\
**Last updated:** [January 10, 2022, 12:21am UTC](https://discourse.julialang.org/t/application-of-julia-in-operation-research-and-supply-chain/74300 "2022-01-10T00:21:29Z")

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Here, I am attaching the links for some posts that I found helpful to introduce Julia to Supply chain and operation research in general. Any books that cover this topic in a more detailed way?

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## [Implementation of composite quantile loss for Flux](https://discourse.julialang.org/t/implementation-of-composite-quantile-loss-for-flux/73978)

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**Author:** [@johnbb](https://discourse.julialang.org/u/johnbb)\
**Replies:** 7\
**Last updated:** [January 9, 2022, 10:55pm UTC](https://discourse.julialang.org/t/implementation-of-composite-quantile-loss-for-flux/73978 "2022-01-09T22:55:27Z")

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The composite quantile loss for a set of quantiles can be defined as \\sum\_i \\sum\_ j (p\_j - 1\\{y\_i \< q\_{ji}\\}) (y\_i - q\_{ji}) where p\_j \\in(0,1) denote the j-th quantile level/probability, y\_i the i-th target/observa…

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## [What are the "limitations" of CUDA.jl relative to CPU code and where are they rooted](https://discourse.julialang.org/t/what-are-the-limitations-of-cuda-jl-relative-to-cpu-code-and-where-are-they-rooted/74256)

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**Author:** [@Benny](https://discourse.julialang.org/u/Benny)\
**Replies:** 1\
**Last updated:** [January 9, 2022, 9:41pm UTC](https://discourse.julialang.org/t/what-are-the-limitations-of-cuda-jl-relative-to-cpu-code-and-where-are-they-rooted/74256 "2022-01-09T21:41:05Z")

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Recently got my hands on an entry-level Nvidia GPU, so I started reading through the CUDA.jl docs and some related (and possibly outdated) articles. I definitely noticed that it can get very different from CPU code, and …

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## [In MLJ, can I access individual predictions in an \`EnsembleModel\`?](https://discourse.julialang.org/t/in-mlj-can-i-access-individual-predictions-in-an-ensemblemodel/74302)

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**Author:** [@ablaom](https://discourse.julialang.org/u/ablaom)\
**Replies:** 1\
**Last updated:** [January 9, 2022, 8:28pm UTC](https://discourse.julialang.org/t/in-mlj-can-i-access-individual-predictions-in-an-ensemblemodel/74302 "2022-01-09T20:28:25Z")

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The question in the title is copied from Slack.

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## [Plot DataFrames columns in plotlyjs](https://discourse.julialang.org/t/plot-dataframes-columns-in-plotlyjs/55333)

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**Author:** [@espin](https://discourse.julialang.org/u/espin)\
**Replies:** 19\
**Last updated:** [January 9, 2022, 5:24pm UTC](https://discourse.julialang.org/t/plot-dataframes-columns-in-plotlyjs/55333 "2022-01-09T17:24:42Z")

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I’m trying to plot a DataFrame in plotlyjs(). I’m able to plot 1 column but cant plot more than 1 (I have several around 20 that I have to plot on the same figure). The first column of the df is the data for the x axis,…

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## [Plots title offset (pyplot)](https://discourse.julialang.org/t/plots-title-offset-pyplot/74250)

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**Author:** [@jamblejoe](https://discourse.julialang.org/u/jamblejoe)\
**Replies:** 2\
**Last updated:** [January 9, 2022, 2:19pm UTC](https://discourse.julialang.org/t/plots-title-offset-pyplot/74250 "2022-01-09T14:19:47Z")

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How do I offset titles in Plots.jl? For example when the title overlaps with the colorbar using Plots pyplot() heatmap(rand(100,100); title="title", titlefontsize=40, colorbar=:top) produces something like

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## [Package management of a package with different versions required by other packages](https://discourse.julialang.org/t/package-management-of-a-package-with-different-versions-required-by-other-packages/74236)

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**Author:** [@Xijiang\_Yu](https://discourse.julialang.org/u/Xijiang_Yu)\
**Replies:** 5\
**Last updated:** [January 8, 2022, 9:32pm UTC](https://discourse.julialang.org/t/package-management-of-a-package-with-different-versions-required-by-other-packages/74236 "2022-01-08T21:32:33Z")

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I recently had a trouble with package Octavian. Because it can deal with BitArray or Int8 matrix, it has a great advantage over BLAS. It made it possible to deal with much larger matrix than BLAS. The problem is that wit…

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## [Coupled non-linear PDEs using DifferentialEquations.jl and the MOL](https://discourse.julialang.org/t/coupled-non-linear-pdes-using-differentialequations-jl-and-the-mol/74139)

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**Author:** [@Iddingsite](https://discourse.julialang.org/u/Iddingsite)\
**Replies:** 10\
**Last updated:** [January 8, 2022, 1:58pm UTC](https://discourse.julialang.org/t/coupled-non-linear-pdes-using-differentialequations-jl-and-the-mol/74139 "2022-01-08T13:58:39Z")

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Hi everyone, I am trying to solve 2 coupled non-linear PDEs using the MOL with DifferentialEquations.jl and Finite differences first in 1D and I am stuck somewhere. My two equations describe the evolution of a porosity…

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## [Is JuMP the right package for large square models?](https://discourse.julialang.org/t/is-jump-the-right-package-for-large-square-models/74214)

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**Author:** [@MartinBonde](https://discourse.julialang.org/u/MartinBonde)\
**Replies:** 3\
**Last updated:** [January 8, 2022, 8:43am UTC](https://discourse.julialang.org/t/is-jump-the-right-package-for-large-square-models/74214 "2022-01-08T08:43:10Z")

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Is there a well defined ‘domain boundary’ between ModelingToolkit and JuMP? I currently use GAMS and the Conopt solver to solve very large square systems of non-linear equations. I.e. exactly as many constraints as free…

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## [Accessing ecdfplot from CairoMakie](https://discourse.julialang.org/t/accessing-ecdfplot-from-cairomakie/74219)

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**Author:** [@bicepjai](https://discourse.julialang.org/u/bicepjai)\
**Replies:** 1\
**Last updated:** [January 8, 2022, 12:43am UTC](https://discourse.julialang.org/t/accessing-ecdfplot-from-cairomakie/74219 "2022-01-08T00:43:16Z")

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I see cairomakie is moved to makie . New makie has been released, do we still need to install cairomakie separately ? I am trying to use ecdfplot and have not found a way. everytime i install cairomakie, makie version ge…

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## [Turing with ODE model using dualcache causes error](https://discourse.julialang.org/t/turing-with-ode-model-using-dualcache-causes-error/74166)

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**Author:** [@jacobusmmsmit](https://discourse.julialang.org/u/jacobusmmsmit)\
**Replies:** 1\
**Last updated:** [January 7, 2022, 6:58am UTC](https://discourse.julialang.org/t/turing-with-ode-model-using-dualcache-causes-error/74166 "2022-01-07T06:58:02Z")

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I am running into a similar problem as this thread which unfortunately didn’t resolve the issue in my case. I think I am perhaps misusing dualcache in the definition of my update function and I would be grateful for any …

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## [NLParameter](https://discourse.julialang.org/t/nlparameter/74163)

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**Author:** [@jacob-roth](https://discourse.julialang.org/u/jacob-roth)\
**Replies:** 2\
**Last updated:** [January 6, 2022, 11:12pm UTC](https://discourse.julialang.org/t/nlparameter/74163 "2022-01-06T23:12:17Z")

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Is there any way to register an NLParameter as part of a Model? For example, I would like to create a model model = Model(Ipopt.Optimizer) @variable(model, x) @NLParameter(model, p == 0) @NLobjective(model, Min, (x + p)…

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## [Julia Package for UI development](https://discourse.julialang.org/t/julia-package-for-ui-development/39469)

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**Author:** [@saraflgarcia](https://discourse.julialang.org/u/saraflgarcia)\
**Replies:** 3\
**Last updated:** [January 6, 2022, 2:14pm UTC](https://discourse.julialang.org/t/julia-package-for-ui-development/39469 "2022-01-06T14:14:29Z")

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Hi everyone, I want to develop a GUI written in Julia, with the following requirements: Widgets: top menu, tabs, checkboxes, radio button, range sliders, text-fields Widgets state: enabled/disabled, hidden/unhidden I…

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## [Julia adding an older version of my updated Gurobi Solber](https://discourse.julialang.org/t/julia-adding-an-older-version-of-my-updated-gurobi-solber/74034)

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**Author:** [@konsath](https://discourse.julialang.org/u/konsath)\
**Replies:** 17\
**Last updated:** [January 6, 2022, 12:14am UTC](https://discourse.julialang.org/t/julia-adding-an-older-version-of-my-updated-gurobi-solber/74034 "2022-01-06T00:14:35Z")

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Hi! I’m working with Julia 1.6.5 and Gurobi 9.5.0 on Visual Studio. I’ve acquired an academic license and have uninstall and reinstall everything twice. I can’t figure out why when adding Gurobi, Julia chooses a previous…

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## [Function to Calculate Kappa](https://discourse.julialang.org/t/function-to-calculate-kappa/72852)

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**Author:** [@Rahul](https://discourse.julialang.org/u/Rahul)\
**Replies:** 5\
**Last updated:** [January 5, 2022, 11:04pm UTC](https://discourse.julialang.org/t/function-to-calculate-kappa/72852 "2022-01-05T23:04:31Z")

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Is there a function to calculate Kappa in MLJ? If no, I wrote a function (shown below) and I am looking for a more efficient implementation. function kappa(predictions, original) # Confusion matrix confmat = ML…

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## [Is there a findmin(A) that uses local search instead of visiting all elements of matrix A?](https://discourse.julialang.org/t/is-there-a-findmin-a-that-uses-local-search-instead-of-visiting-all-elements-of-matrix-a/74045)

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**Author:** [@NiclasMattsson](https://discourse.julialang.org/u/NiclasMattsson)\
**Replies:** 8\
**Last updated:** [January 5, 2022, 7:29am UTC](https://discourse.julialang.org/t/is-there-a-findmin-a-that-uses-local-search-instead-of-visiting-all-elements-of-matrix-a/74045 "2022-01-05T07:29:47Z")

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I have a large matrix that contains sampled values of a convex 2D function. I want to find the minimum efficiently without visiting all elements, given indexes for a good starting guess close to the minimum. For example…

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## [Bounded sciml\_train problem error, ArgumentError: Initial x is not in](https://discourse.julialang.org/t/bounded-sciml-train-problem-error-argumenterror-initial-x-is-not-in/73710)

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**Author:** [@willsharpless](https://discourse.julialang.org/u/willsharpless)\
**Replies:** 1\
**Last updated:** [January 5, 2022, 6:09pm UTC](https://discourse.julialang.org/t/bounded-sciml-train-problem-error-argumenterror-initial-x-is-not-in/73710 "2022-01-05T18:09:48Z")

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Hi, I have been getting this initialization error when I try to do iterative box optimization with DiffEqFlux.sciml\_train. I am attempting to optimize sets of parameters for which the loss function slightly varies for d…

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## [Error while parallelizing](https://discourse.julialang.org/t/error-while-parallelizing/74049)

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**Author:** [@Sumit\_Malbari](https://discourse.julialang.org/u/Sumit_Malbari)\
**Replies:** 0\
**Last updated:** [January 4, 2022, 5:43pm UTC](https://discourse.julialang.org/t/error-while-parallelizing/74049 "2022-01-04T17:43:30Z")

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Hi All, I ran JULIA\_COPY\_STACKS=yes julia -e ‘using Pkg;Pkg.add(Pkg.PackageSpec(;name=“Spark”, version=“0.5.1”));Pkg.build(“Spark”);using Spark;Spark.init();sc = SparkContext(master=“yarn”);’ all this worked fine. C…

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## [How to add CUDA as optional dependency?](https://discourse.julialang.org/t/how-to-add-cuda-as-optional-dependency/73077)

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**Author:** [@juliohm](https://discourse.julialang.org/u/juliohm)\
**Replies:** 19\
**Last updated:** [January 5, 2022, 3:44pm UTC](https://discourse.julialang.org/t/how-to-add-cuda-as-optional-dependency/73077 "2022-01-05T15:44:46Z")

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Suppose I have a package and that I am interested in providing an option to end users to speed up their calculations in the presence of a NVIDIA GPU. Not everyone will benefit from this option and so I can’t add CUDA as …

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## [LightGraphs.jl/Graphs.jl only values from half the cartesian plane is needed](https://discourse.julialang.org/t/lightgraphs-jl-graphs-jl-only-values-from-half-the-cartesian-plane-is-needed/74080)

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**Author:** [@HelgavonLichtenstein](https://discourse.julialang.org/u/HelgavonLichtenstein)\
**Replies:** 3\
**Last updated:** [January 5, 2022, 1:34pm UTC](https://discourse.julialang.org/t/lightgraphs-jl-graphs-jl-only-values-from-half-the-cartesian-plane-is-needed/74080 "2022-01-05T13:34:50Z")

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Hi, this is a continuation of finding link distances between species in a food web. It’s been a few months so I am starting a new topic. I can find distances between species, but when I want to randomly choose a species …

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## [Flux.jl Restrict Gradients to Non-Zero values in sparse layer](https://discourse.julialang.org/t/flux-jl-restrict-gradients-to-non-zero-values-in-sparse-layer/72124)

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**Author:** [@james-a-mcmanus](https://discourse.julialang.org/u/james-a-mcmanus)\
**Replies:** 5\
**Last updated:** [January 5, 2022, 11:07am UTC](https://discourse.julialang.org/t/flux-jl-restrict-gradients-to-non-zero-values-in-sparse-layer/72124 "2022-01-05T11:07:06Z")

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Hi, I’m trying to make a custom network layer with sparse weights. I only want to train the non-zero values of the layer, however when I try to create a gradient from this the gradient returns nothing. Here is a MWE. u…

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## [Missing records in my FASTA file when writing new FASTAs](https://discourse.julialang.org/t/missing-records-in-my-fasta-file-when-writing-new-fastas/74032)

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**Author:** [@Lamma](https://discourse.julialang.org/u/Lamma)\
**Replies:** 3\
**Last updated:** [January 5, 2022, 10:27am UTC](https://discourse.julialang.org/t/missing-records-in-my-fasta-file-when-writing-new-fastas/74032 "2022-01-05T10:27:36Z")

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I have a co-assembly and some alignment data telling me if a reads from a sample that helped spawn that co-assembly align to a contig. I am using this to write a fasta file for that sample. t1 = Threads.@spawn DataF…

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## [JuMP constraint: how to use more than one filter elements in the sets](https://discourse.julialang.org/t/jump-constraint-how-to-use-more-than-one-filter-elements-in-the-sets/73928)

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**Author:** [@Luiz\_Monteiro](https://discourse.julialang.org/u/Luiz_Monteiro)\
**Replies:** 2\
**Last updated:** [January 5, 2022, 12:53am UTC](https://discourse.julialang.org/t/jump-constraint-how-to-use-more-than-one-filter-elements-in-the-sets/73928 "2022-01-05T00:53:39Z")

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Hi, In JuMP, I need to implement a constraint that uses more than one filter elements in the sets. It seems that JuMP accepts only one filter. The error message is:“There can be at most one filtering condition, which i…

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## [JuMP, one constraint with two inequalities in the expression, is it possible?](https://discourse.julialang.org/t/jump-one-constraint-with-two-inequalities-in-the-expression-is-it-possible/73843)

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**Author:** [@Luiz\_Monteiro](https://discourse.julialang.org/u/Luiz_Monteiro)\
**Replies:** 4\
**Last updated:** [January 5, 2022, 12:52am UTC](https://discourse.julialang.org/t/jump-one-constraint-with-two-inequalities-in-the-expression-is-it-possible/73843 "2022-01-05T00:52:45Z")

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Hi, I am having trouble to implement the following constraint (with two inequalities). Does JuMP accept this kind of expression? @constraint(model, con4\[i in Vtotal, j in Vcustomer; i != j\], x\[i,j\] \* Menergy\[i,j\] - (1-x…

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## [TCAD and julia?](https://discourse.julialang.org/t/tcad-and-julia/49590)

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**Author:** [@feanor12](https://discourse.julialang.org/u/feanor12)\
**Replies:** 3\
**Last updated:** [January 4, 2022, 8:38pm UTC](https://discourse.julialang.org/t/tcad-and-julia/49590 "2022-01-04T20:38:05Z")

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Is there a package which can solve drift-diffusion and Poisson’s equations for isotype heterojunctions? I think 1D would be enough. I am asking as I would be interested in understanding thermal emission or tunneling tra…

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## [ERROR: LoadError: Unable to locate Gurobi installation](https://discourse.julialang.org/t/error-loaderror-unable-to-locate-gurobi-installation/74051)

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**Author:** [@konsath](https://discourse.julialang.org/u/konsath)\
**Replies:** 2\
**Last updated:** [January 4, 2022, 8:09pm UTC](https://discourse.julialang.org/t/error-loaderror-unable-to-locate-gurobi-installation/74051 "2022-01-04T20:09:50Z")

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I’m using Julia 1.6.5 and Gurobi 9.5.0 but right now Julia is adding an outdated version of Gurobi that doesn’t match my Path (9.5.0). Could anyone provide some insight maybe? :slight\_smile: ‘’’ julia\> Pkg.build(“Gurob…

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## [Chebfun equivalent for differentiation matrices in Julia?](https://discourse.julialang.org/t/chebfun-equivalent-for-differentiation-matrices-in-julia/74042)

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**Author:** [@yewalenikhil65](https://discourse.julialang.org/u/yewalenikhil65)\
**Replies:** 4\
**Last updated:** [January 4, 2022, 6:04pm UTC](https://discourse.julialang.org/t/chebfun-equivalent-for-differentiation-matrices-in-julia/74042 "2022-01-04T18:04:12Z")

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Is there yet a differentiation matrices calculating tool in some Julia package ? Something similar to https://github.com/chebfun/chebfun/blob/master/diffmat.m I have tried searching in JuliaApproximation community but c…

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## [Setting up Julia on Spark on AWS EMR](https://discourse.julialang.org/t/setting-up-julia-on-spark-on-aws-emr/63781)

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**Author:** [@Sumit\_Malbari](https://discourse.julialang.org/u/Sumit_Malbari)\
**Replies:** 24\
**Last updated:** [January 4, 2022, 3:13pm UTC](https://discourse.julialang.org/t/setting-up-julia-on-spark-on-aws-emr/63781 "2022-01-04T15:13:50Z")

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Hi folks, I want to use Julia on Spark on AWS EMR as this is one of the requirement at my workplace. I tried to follow the steps from Julia & Spark but I was not able to succeed. If anyone has implemented it on AWS EM…

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## [LP Warm Starts - using Gurobi with JuMP](https://discourse.julialang.org/t/lp-warm-starts-using-gurobi-with-jump/73840)

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**Author:** [@bjr221](https://discourse.julialang.org/u/bjr221)\
**Replies:** 6\
**Last updated:** [January 3, 2022, 11:48pm UTC](https://discourse.julialang.org/t/lp-warm-starts-using-gurobi-with-jump/73840 "2022-01-03T23:48:32Z")

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Is there any way to warm start (choose initial vertex for dual simplex algorithm) for a linear program that you’ve created? I have tried using the “PStart” attribute for LPs to no avail, and the “.start” attribute is for…

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