# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=458

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**Page:** 459

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## [Problem with Weave code](https://discourse.julialang.org/t/problem-with-weave-code/35862)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 9\
**Last updated:** [March 12, 2020, 7:40am UTC](https://discourse.julialang.org/t/problem-with-weave-code/35862 "2020-03-12T07:40:16Z")

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weave("C:/Users/brett/OneDrive/Documents/", out\_path=C:/Users/brett/OneDrive/Documents/ECON214Assignment3.pdf, doctype="md2pdf") When I put in this code I get an error. What am I doing wrong?

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## [Plotting with PGFPlots not able to superimpose graphs in a for loop](https://discourse.julialang.org/t/plotting-with-pgfplots-not-able-to-superimpose-graphs-in-a-for-loop/35782)

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**Author:** [@JosephPollacco](https://discourse.julialang.org/u/JosephPollacco)\
**Replies:** 7\
**Last updated:** [March 12, 2020, 7:37am UTC](https://discourse.julialang.org/t/plotting-with-pgfplots-not-able-to-superimpose-graphs-in-a-for-loop/35782 "2020-03-12T07:37:01Z")

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I am plotting with PGFPlots JULIA, and I would like to superimpose graphs in the loop such as in Plots by using Plot!. But I was only successful to produce separate graphs: X = ∑T\[1:θcalibr.Nt\] Plot\_θcalibr = Gro…

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## [Add variables in a container](https://discourse.julialang.org/t/add-variables-in-a-container/35798)

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**Author:** [@remi-garcia](https://discourse.julialang.org/u/remi-garcia)\
**Replies:** 11\
**Last updated:** [March 12, 2020, 7:06am UTC](https://discourse.julialang.org/t/add-variables-in-a-container/35798 "2020-03-12T07:06:10Z")

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Hello, I’ve found a workaround to my problem but I wonder if there is a better way to solve it. This is what I do: using JuMP model = JuMP.Model() n = 10 @variable(model, -5 \<= x0 \<= 5, Int) @variable(model, -5 \<= x\[1…

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## [Dataframe identify rows](https://discourse.julialang.org/t/dataframe-identify-rows/35819)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 1\
**Last updated:** [March 11, 2020, 6:42am UTC](https://discourse.julialang.org/t/dataframe-identify-rows/35819 "2020-03-11T06:42:33Z")

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I made a data frame from an xlsx spreadsheet, which has every month from Jan 1976- to Feb 2020 as columns, and as rows these variables. Month-year Population Labour force Employment Full-time employment Part-tim…

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## [Explicitly defining dependent variables vs allowing solver to figure it out](https://discourse.julialang.org/t/explicitly-defining-dependent-variables-vs-allowing-solver-to-figure-it-out/35114)

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**Author:** [@gobs](https://discourse.julialang.org/u/gobs)\
**Replies:** 10\
**Last updated:** [March 11, 2020, 3:20pm UTC](https://discourse.julialang.org/t/explicitly-defining-dependent-variables-vs-allowing-solver-to-figure-it-out/35114 "2020-03-11T15:20:53Z")

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I have an energy system optimisation model with storage. The energy balance for the storage technology looks something like this: e\[t\] = e\[t-1\] + eff \* c\[t\] - d\[t\] The only real decision variables are the charging and…

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## [Read Geopackage Layers to dataframe](https://discourse.julialang.org/t/read-geopackage-layers-to-dataframe/35837)

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**Author:** [@patrickplagowski](https://discourse.julialang.org/u/patrickplagowski)\
**Replies:** 1\
**Last updated:** [March 11, 2020, 3:15pm UTC](https://discourse.julialang.org/t/read-geopackage-layers-to-dataframe/35837 "2020-03-11T15:15:10Z")

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Hi everyone, I started applying ArchGDAL to read geopackage layers. How can one read geopackage layers to dataframes (like geopandas in python)? Motivation: I’d like to avoid for loops and many if/else statements in th…

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## [Question on Bayesian Inference with Julia, using Turing and/or AdvancedHMC and/or Distributions](https://discourse.julialang.org/t/question-on-bayesian-inference-with-julia-using-turing-and-or-advancedhmc-and-or-distributions/35776)

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**Author:** [@HarrisonWilde](https://discourse.julialang.org/u/HarrisonWilde)\
**Replies:** 11\
**Last updated:** [March 11, 2020, 11:55am UTC](https://discourse.julialang.org/t/question-on-bayesian-inference-with-julia-using-turing-and-or-advancedhmc-and-or-distributions/35776 "2020-03-11T11:55:25Z")

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I am looking to run some experiments in Julia after growing tired of jumping in and out of Stan and suffering from some performance issues that I think Julia could help eliminate. I am looking to do MCMC to learn paramet…

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## [Loading COVID-19 CSV data](https://discourse.julialang.org/t/loading-covid-19-csv-data/35820)

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**Author:** [@Glen](https://discourse.julialang.org/u/Glen)\
**Replies:** 2\
**Last updated:** [March 11, 2020, 4:17am UTC](https://discourse.julialang.org/t/loading-covid-19-csv-data/35820 "2020-03-11T04:17:16Z")

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Hi Julians, I am trying to read the latest COVID-19 data to do analysis, from here: https://github.com/CSSEGISandData/COVID-19/blob/master/csse\_covid\_19\_data/csse\_covid\_19\_time\_series/time\_series\_19-covid-Confirmed.csv …

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## [CBC and CLP solver version with JuMP](https://discourse.julialang.org/t/cbc-and-clp-solver-version-with-jump/35795)

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**Author:** [@bandaya](https://discourse.julialang.org/u/bandaya)\
**Replies:** 2\
**Last updated:** [March 10, 2020, 9:17pm UTC](https://discourse.julialang.org/t/cbc-and-clp-solver-version-with-jump/35795 "2020-03-10T21:17:33Z")

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I am running an optimization problem with CBC solver but it is taking forever with around 1100 binary variables. The same problem is solved in about 2 minutes if I reduce the number of variables to 900. I suspect that t…

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## [Simple optimization problem via flux](https://discourse.julialang.org/t/simple-optimization-problem-via-flux/35805)

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**Author:** [@samantp](https://discourse.julialang.org/u/samantp)\
**Replies:** 0\
**Last updated:** [March 10, 2020, 5:41pm UTC](https://discourse.julialang.org/t/simple-optimization-problem-via-flux/35805 "2020-03-10T17:41:37Z")

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I have a prediction function, called NTCP which takes several fixed input parameters: dpf,nf,ab. It also takes in some parameters that I am looking to optimize: n, TD, Y as well as my input data dvh\_all. The fixed parame…

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## [Is it possible perform reverse mode differentiation (Flux.jl with Zygote.jl) of a forward mode differentiation result (e.g. ForwardDiff)?](https://discourse.julialang.org/t/is-it-possible-perform-reverse-mode-differentiation-flux-jl-with-zygote-jl-of-a-forward-mode-differentiation-result-e-g-forwarddiff/30945)

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**Author:** [@Sleort](https://discourse.julialang.org/u/Sleort)\
**Replies:** 3\
**Last updated:** [March 10, 2020, 5:41am UTC](https://discourse.julialang.org/t/is-it-possible-perform-reverse-mode-differentiation-flux-jl-with-zygote-jl-of-a-forward-mode-differentiation-result-e-g-forwarddiff/30945 "2020-03-10T05:41:45Z")

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Say I have some function f: \\mathbb{R}^m \\times \\mathbb{R} \\to \\mathbb{R}^n, i.e. f(\\theta, x) is some vector for a given set of parameters \\theta and a scalar x. I would now like to calculate the gradient \\nabla\_\\theta …

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## [How to avoid large movement of data when using remotecall\_fetch?](https://discourse.julialang.org/t/how-to-avoid-large-movement-of-data-when-using-remotecall-fetch/35746)

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**Author:** [@zxjroger](https://discourse.julialang.org/u/zxjroger)\
**Replies:** 0\
**Last updated:** [March 9, 2020, 6:41am UTC](https://discourse.julialang.org/t/how-to-avoid-large-movement-of-data-when-using-remotecall-fetch/35746 "2020-03-09T06:41:53Z")

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I wrote a code to solve 10k linear programming problems in parallel. I timed this code on a computer with nprocs()=4. Ideally, it should be three times faster than non-parallel code, however, it is only two times faster.…

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## [DataFrames not showing value](https://discourse.julialang.org/t/dataframes-not-showing-value/35743)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 11\
**Last updated:** [March 9, 2020, 9:25pm UTC](https://discourse.julialang.org/t/dataframes-not-showing-value/35743 "2020-03-09T21:25:49Z")

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d = .05 n = .01 g = .015 s = .3 k = 6 i=s t=0:50 yn= function(t) ((y-k)+I\*t) using DataFrames df = DataFrame(A = yn, B = t) print(df) When I run this, istead of giving each value of yn for each value of t, it has #1…

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## [Reading from a KNetArray within a GPU kernel function](https://discourse.julialang.org/t/reading-from-a-knetarray-within-a-gpu-kernel-function/35767)

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**Author:** [@dfenn](https://discourse.julialang.org/u/dfenn)\
**Replies:** 0\
**Last updated:** [March 9, 2020, 7:46pm UTC](https://discourse.julialang.org/t/reading-from-a-knetarray-within-a-gpu-kernel-function/35767 "2020-03-09T19:46:40Z")

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Is it possible to use KNetArrays from within a custom GPU kernel function? The following MWE fails: using Knet using GPUArrays knArray = KnetArray(rand(4,4)) function kernel(state, knArray) temp = knArray\[1\] …

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## [Simplest way to have numerical FOC of a function?](https://discourse.julialang.org/t/simplest-way-to-have-numerical-foc-of-a-function/35754)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 1\
**Last updated:** [March 9, 2020, 3:22pm UTC](https://discourse.julialang.org/t/simplest-way-to-have-numerical-foc-of-a-function/35754 "2020-03-09T15:22:37Z")

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I have the following function for which I need to find the First Order Conditions with respect to one parameter, let’s say \\mathbb{u}: J(u,v,Y,λ) = sum(skipmissing((Y-(u \* v')) .^ 2))/2 + (λ/2) \* (norm(u)^2 + norm(v)^2…

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## [How to solve this error while installing SCENRED2](https://discourse.julialang.org/t/how-to-solve-this-error-while-installing-scenred2/35413)

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**Author:** [@SAH](https://discourse.julialang.org/u/SAH)\
**Replies:** 2\
**Last updated:** [March 9, 2020, 2:41pm UTC](https://discourse.julialang.org/t/how-to-solve-this-error-while-installing-scenred2/35413 "2020-03-09T14:41:29Z")

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I am trying to add a scenario reduction package \[available here\] in Julia and getting an error. In fact, I run these 2 lines as discribed in the link: julia\> Pkg.clone("https://github.com/trigaut/Scenred2.jl.git") julia\>…

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## [RESTful web services](https://discourse.julialang.org/t/restful-web-services/10046)

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**Author:** [@tk3369](https://discourse.julialang.org/u/tk3369)\
**Replies:** 18\
**Last updated:** [March 9, 2020, 10:38am UTC](https://discourse.julialang.org/t/restful-web-services/10046 "2020-03-09T10:38:58Z")

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What package(s) may I use to build RESTful web services? Is there any tutorial around?

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## [What is the best way to factorize/decompose a covariance matrix?](https://discourse.julialang.org/t/what-is-the-best-way-to-factorize-decompose-a-covariance-matrix/35316)

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**Author:** [@zxjroger](https://discourse.julialang.org/u/zxjroger)\
**Replies:** 21\
**Last updated:** [March 9, 2020, 2:08am UTC](https://discourse.julialang.org/t/what-is-the-best-way-to-factorize-decompose-a-covariance-matrix/35316 "2020-03-09T02:08:58Z")

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I need to draw from a certain multivariate normal distribution. To do so, I draw from standard normal distribution, then transform them to draws from multivariate normal distribution. Because the covariance matrix is onl…

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## [Get an error when keep certain variables only on the main process](https://discourse.julialang.org/t/get-an-error-when-keep-certain-variables-only-on-the-main-process/35738)

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**Author:** [@zxjroger](https://discourse.julialang.org/u/zxjroger)\
**Replies:** 0\
**Last updated:** [March 8, 2020, 11:58pm UTC](https://discourse.julialang.org/t/get-an-error-when-keep-certain-variables-only-on-the-main-process/35738 "2020-03-08T23:58:08Z")

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I am trying to learn parallel computing in Julia. I want to send something to every processes, but keep other things only at the main process. I had the following weird error. My sample code is (for simplicity): using …

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## [Need help with 'Accelerating optimization via machine learning with surrogate models'](https://discourse.julialang.org/t/need-help-with-accelerating-optimization-via-machine-learning-with-surrogate-models/35717)

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**Author:** [@viralnatani](https://discourse.julialang.org/u/viralnatani)\
**Replies:** 2\
**Last updated:** [March 8, 2020, 12:41pm UTC](https://discourse.julialang.org/t/need-help-with-accelerating-optimization-via-machine-learning-with-surrogate-models/35717 "2020-03-08T12:41:30Z")

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Hello everyone! I am a student and willing to participate in Google Summer Of Code 2020. I am interested in working on project “Accelerating optimization via machine learning with surrogate models”. But I am unable to fi…

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## [Discrete heatmap in Plots.jl](https://discourse.julialang.org/t/discrete-heatmap-in-plots-jl/35708)

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**Author:** [@c1991](https://discourse.julialang.org/u/c1991)\
**Replies:** 1\
**Last updated:** [March 8, 2020, 6:12am UTC](https://discourse.julialang.org/t/discrete-heatmap-in-plots-jl/35708 "2020-03-08T06:12:34Z")

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The following code gives me exactly what I need except that I do not want a continuous colorbar. How do I get a discrete color bar (i.e. 1 = “red”, 2 = “blue”, and 3 = “green”, etc.)? timePeriods = 12 nodes = 15 ys =…

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## [Visualizing a 3D volume in Makie: Lighting, smoothness](https://discourse.julialang.org/t/visualizing-a-3d-volume-in-makie-lighting-smoothness/35263)

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**Author:** [@dalarev](https://discourse.julialang.org/u/dalarev)\
**Replies:** 7\
**Last updated:** [March 8, 2020, 3:38am UTC](https://discourse.julialang.org/t/visualizing-a-3d-volume-in-makie-lighting-smoothness/35263 "2020-03-08T03:38:43Z")

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In plotting discrete 3D arrays using Makie, how can one modify the lighting and smoothness properties? Here is an example of a thick, extruded cross geometry constructed as a binary 3D array. (Figure on left) The lighti…

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## [Combining distributed computing / multithreading](https://discourse.julialang.org/t/combining-distributed-computing-multithreading/24320)

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**Author:** [@moudbis](https://discourse.julialang.org/u/moudbis)\
**Replies:** 7\
**Last updated:** [March 7, 2020, 10:42am UTC](https://discourse.julialang.org/t/combining-distributed-computing-multithreading/24320 "2020-03-07T10:42:06Z")

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Hello everyone, I’m trying to use multithreading in Julia 1.0 over an HPC cluster. This HPC cluster own differents nodes (separate CPU units) and each node has several cores. I want to run Julia parallel code over thi…

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## [Recursive call with ForwardDiff](https://discourse.julialang.org/t/recursive-call-with-forwarddiff/35678)

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**Author:** [@edljk](https://discourse.julialang.org/u/edljk)\
**Replies:** 0\
**Last updated:** [March 7, 2020, 8:34am UTC](https://discourse.julialang.org/t/recursive-call-with-forwarddiff/35678 "2020-03-07T08:34:05Z")

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Dear all, I considered the following piece of code. The Forward package is impressive in its flexibility! Nevertheless, I wonder if I am not missing some obvious optimization? Any suggestion are welcome. using ForwardD…

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## [Density-based clustering with incomplete distance matrix](https://discourse.julialang.org/t/density-based-clustering-with-incomplete-distance-matrix/35675)

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**Author:** [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)\
**Replies:** 0\
**Last updated:** [March 7, 2020, 4:12am UTC](https://discourse.julialang.org/t/density-based-clustering-with-incomplete-distance-matrix/35675 "2020-03-07T04:12:26Z")

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I am looking for a clustering algorithm (probably density based) that works with custom distances (I have my own non-Euclidean distance metric) and can work on very large datasets. I can evaluate nearest neighbors quickl…

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## [Trying to use Measurement.jl with DifferentialEquations.jl](https://discourse.julialang.org/t/trying-to-use-measurement-jl-with-differentialequations-jl/35655)

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**Author:** [@Hossein\_Haghi](https://discourse.julialang.org/u/Hossein_Haghi)\
**Replies:** 11\
**Last updated:** [March 6, 2020, 10:14pm UTC](https://discourse.julialang.org/t/trying-to-use-measurement-jl-with-differentialequations-jl/35655 "2020-03-06T22:14:23Z")

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In the example below I am trying to use Measurement.jl with DiffernetialEquations.jl to solve an ODE with error propagation. clearconsole() @time using DifferentialEquations, Measurements, MATLAB function Buckle(du,u,…

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## [Julia breaks down when using JuMP through Atom](https://discourse.julialang.org/t/julia-breaks-down-when-using-jump-through-atom/35658)

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**Author:** [@Ksun46](https://discourse.julialang.org/u/Ksun46)\
**Replies:** 1\
**Last updated:** [March 6, 2020, 7:51pm UTC](https://discourse.julialang.org/t/julia-breaks-down-when-using-jump-through-atom/35658 "2020-03-06T19:51:41Z")

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Hi all, I am using Julia through Juno/Atom on a Mac, and got the following error today I can run my code through the terminal through. I am not sure what’s going on here. Any suggestions? Thanks.

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## [Generalized eigenvalues with Diagonal B](https://discourse.julialang.org/t/generalized-eigenvalues-with-diagonal-b/35372)

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**Author:** [@tobydriscoll](https://discourse.julialang.org/u/tobydriscoll)\
**Replies:** 4\
**Last updated:** [March 6, 2020, 5:45pm UTC](https://discourse.julialang.org/t/generalized-eigenvalues-with-diagonal-b/35372 "2020-03-06T17:45:13Z")

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Looking to solve a generalized eigenproblem. All is well here: julia\> A = rand(4,4); julia\> B = rand(4,4); julia\> eigen(A,B) GeneralizedEigen{Complex{Float64},Complex{Float64},Array{Complex{Float64},2},Array{Complex{Flo…

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## [Vegalite.jl: levels and DataFrames](https://discourse.julialang.org/t/vegalite-jl-levels-and-dataframes/35638)

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**Author:** [@Usor](https://discourse.julialang.org/u/Usor)\
**Replies:** 10\
**Last updated:** [March 6, 2020, 4:15pm UTC](https://discourse.julialang.org/t/vegalite-jl-levels-and-dataframes/35638 "2020-03-06T16:15:18Z")

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I was reading about levels for DataFrames. How exactly can they be useful with Vegalite.jl? I read about for example display purposes: when I tried to plot some data with this in mind (already some months ago), there wa…

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## [Predicting discrete events == expenses](https://discourse.julialang.org/t/predicting-discrete-events-expenses/35612)

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**Author:** [@yakir12](https://discourse.julialang.org/u/yakir12)\
**Replies:** 12\
**Last updated:** [March 6, 2020, 4:02pm UTC](https://discourse.julialang.org/t/predicting-discrete-events-expenses/35612 "2020-03-06T16:02:48Z")

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This question is 50% not about Julia. When I try to predict how much money I will spend in the future, I sum expenses per month for multiple months and base my stats on that set of monthly expenses. But, it feels like I…

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