# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=457

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**Page:** 458

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## [How to call nonlinear solver in MathOptInterface](https://discourse.julialang.org/t/how-to-call-nonlinear-solver-in-mathoptinterface/36001)

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**Author:** [@zxjroger](https://discourse.julialang.org/u/zxjroger)\
**Replies:** 3\
**Last updated:** [March 17, 2020, 3:06pm UTC](https://discourse.julialang.org/t/how-to-call-nonlinear-solver-in-mathoptinterface/36001 "2020-03-17T15:06:53Z")

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I am trying to move from MathProgBase to MathOptInterface. My code works for the former package, but after I rewrote it using the latter package, I got an error saying Ipopt: Failed to construct problem. I believe it is …

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## [2-dimensional DataFrame column](https://discourse.julialang.org/t/2-dimensional-dataframe-column/36060)

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**Author:** [@martincornejo](https://discourse.julialang.org/u/martincornejo)\
**Replies:** 2\
**Last updated:** [March 17, 2020, 3:05pm UTC](https://discourse.julialang.org/t/2-dimensional-dataframe-column/36060 "2020-03-17T15:05:32Z")

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MATLAB-tables and pandas-dataframe enable more than one element per cell (column-row pair). Is the same possible in Julia DataFrames? I tried for example: julia\> df = DataFrame(A = ones(10), B = ones(10,2)) which promp…

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## [\`empty!\` for JuMP.Model or JuMP.direct\_model?](https://discourse.julialang.org/t/empty-for-jump-model-or-jump-direct-model/35673)

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**Author:** [@Henrique\_Becker](https://discourse.julialang.org/u/Henrique_Becker)\
**Replies:** 12\
**Last updated:** [March 17, 2020, 3:03am UTC](https://discourse.julialang.org/t/empty-for-jump-model-or-jump-direct-model/35673 "2020-03-17T03:03:19Z")

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I did not found a way of emptying a model (created with either JuMP.model or JuMP.direct\_model). There is a MathOptInterface.empty!, but it seems I need to call it over backend(model) and after I do that, I cannot add a…

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## [JuMP-dev 2020](https://discourse.julialang.org/t/jump-dev-2020/33158)

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**Author:** [@odow](https://discourse.julialang.org/u/odow)\
**Replies:** 2\
**Last updated:** [March 16, 2020, 7:43pm UTC](https://discourse.julialang.org/t/jump-dev-2020/33158 "2020-03-16T19:43:00Z")

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Dear all, We are pleased to announce that we are now inviting talk submissions for JuMP-dev 2020, to be held June 15-17, 2020 in Louvain-la-Neuve, Belgium, in conjunction with UCLouvain. For more information on JuMP-de…

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## [VegaLite: Text labels on bar charts](https://discourse.julialang.org/t/vegalite-text-labels-on-bar-charts/36048)

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**Author:** [@hellemo](https://discourse.julialang.org/u/hellemo)\
**Replies:** 2\
**Last updated:** [March 16, 2020, 6:38pm UTC](https://discourse.julialang.org/t/vegalite-text-labels-on-bar-charts/36048 "2020-03-16T18:38:04Z")

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I can’t figure out how to show the actual values on a bar chart in VegaLite, I tried adapting the examples but clearly I don’t understand what options are necessary to achieve what I want. I’m able to do each layer more…

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## [Write large Least Square like problems in JuMP](https://discourse.julialang.org/t/write-large-least-square-like-problems-in-jump/35931)

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**Author:** [@dmetivie](https://discourse.julialang.org/u/dmetivie)\
**Replies:** 2\
**Last updated:** [March 16, 2020, 5:43pm UTC](https://discourse.julialang.org/t/write-large-least-square-like-problems-in-jump/35931 "2020-03-16T17:43:08Z")

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Hi, Here is a small code showing the issue I am facing when trying to form large problem (least square like) with JuMP using JuMP, Ipopt, BenchmarkTools p = 500 n = 200 solver = with\_optimizer(Ipopt.Optimizer); ML = …

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## [Flux cannot save a parameters](https://discourse.julialang.org/t/flux-cannot-save-a-parameters/35642)

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**Author:** [@Owolf](https://discourse.julialang.org/u/Owolf)\
**Replies:** 3\
**Last updated:** [March 16, 2020, 4:35pm UTC](https://discourse.julialang.org/t/flux-cannot-save-a-parameters/35642 "2020-03-16T16:35:30Z")

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Dear Julia community, I am trying to save parameters for trained RNN with BSON. However it seems that in latest version of FLUX this is not possible, however https://fluxml.ai says something different. I create rnn as: …

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## [Bipartite weighted network](https://discourse.julialang.org/t/bipartite-weighted-network/35985)

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**Author:** [@mp-crypto](https://discourse.julialang.org/u/mp-crypto)\
**Replies:** 7\
**Last updated:** [March 16, 2020, 3:17pm UTC](https://discourse.julialang.org/t/bipartite-weighted-network/35985 "2020-03-16T15:17:31Z")

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Hello, I am new to Julia (moving from Python). I am trying to generate a bipartite weighted network from a data frame. The data frame contains the “edgelist” (i.e., a column for bottom nodes, and a column for top nodes)…

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## [AssertionError: ctx === CuCurrentContext()](https://discourse.julialang.org/t/assertionerror-ctx-cucurrentcontext/36026)

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**Author:** [@benoitseron](https://discourse.julialang.org/u/benoitseron)\
**Replies:** 3\
**Last updated:** [March 16, 2020, 11:41am UTC](https://discourse.julialang.org/t/assertionerror-ctx-cucurrentcontext/36026 "2020-03-16T11:41:08Z")

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I am trying to setup Julia to use my GPU, out of curiosity as I am a new user. After a few problems, I encoutered this one, where I have not found anything (apart from this which didn’t help me either): using Benchmark…

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## [Does automatic differentiation work for function with discrete argument?](https://discourse.julialang.org/t/does-automatic-differentiation-work-for-function-with-discrete-argument/35947)

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**Author:** [@zxjroger](https://discourse.julialang.org/u/zxjroger)\
**Replies:** 8\
**Last updated:** [March 16, 2020, 1:10am UTC](https://discourse.julialang.org/t/does-automatic-differentiation-work-for-function-with-discrete-argument/35947 "2020-03-16T01:10:13Z")

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I am trying to find the minimizer \\theta of the following nonlinear and non-differentiable function: g(H(X | \\theta),X). Here, X is known and imported from dataset; \\theta=(\\theta\_1,\\theta\_2,\\theta\_3) are the parameters …

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## [Can't seem to get reverse\_diff working in Turing](https://discourse.julialang.org/t/cant-seem-to-get-reverse-diff-working-in-turing/36015)

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**Author:** [@HarrisonWilde](https://discourse.julialang.org/u/HarrisonWilde)\
**Replies:** 10\
**Last updated:** [March 15, 2020, 9:19pm UTC](https://discourse.julialang.org/t/cant-seem-to-get-reverse-diff-working-in-turing/36015 "2020-03-15T21:19:41Z")

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I am having some issues with getting my code to work with reverse\_diff enabled, which I believe would be a good idea due to having around 35 params, I get the following error: ERROR: MethodError: no method matching zero…

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## [PL/Julia extension ( minimal )](https://discourse.julialang.org/t/pl-julia-extension-minimal/34232)

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**Author:** [@ImreSamu](https://discourse.julialang.org/u/ImreSamu)\
**Replies:** 2\
**Last updated:** [March 15, 2020, 7:07am UTC](https://discourse.julialang.org/t/pl-julia-extension-minimal/34232 "2020-03-15T07:07:54Z")

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" The following is only the beginning of an example to create a new procedural language for PostgreSQL. At some point later we will have something that enables user defined functions and stored procedures written in the J…

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## [Cant Install CUDA for gpu](https://discourse.julialang.org/t/cant-install-cuda-for-gpu/35973)

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**Author:** [@shashiracherla](https://discourse.julialang.org/u/shashiracherla)\
**Replies:** 2\
**Last updated:** [March 14, 2020, 4:58pm UTC](https://discourse.julialang.org/t/cant-install-cuda-for-gpu/35973 "2020-03-14T16:58:53Z")

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Hi newbie here, please help me im not able to install CUDA for julia (v1.0) pkg\> add CUDA Updating registry at \`~/.julia/registries/General\` Updating git-repo \`https://github.com/JuliaRegistries/General.git\` ERROR:…

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## [Problem forming a least squares solution](https://discourse.julialang.org/t/problem-forming-a-least-squares-solution/27563)

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**Author:** [@scottstanie](https://discourse.julialang.org/u/scottstanie)\
**Replies:** 13\
**Last updated:** [March 14, 2020, 4:22pm UTC](https://discourse.julialang.org/t/problem-forming-a-least-squares-solution/27563 "2020-03-14T16:22:25Z")

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I’m having trouble formulating a model to minimize ||Ax - b|| Ideally I’m looking to minimize the 1 norm, but in trying to get there I ran into errors that I’m not sure I understand: using JuMP using ECOS model = Mode…

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## [Convex.jl: variables "disappearing" in cumulative constraint](https://discourse.julialang.org/t/convex-jl-variables-disappearing-in-cumulative-constraint/35958)

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**Author:** [@riccardomurri](https://discourse.julialang.org/u/riccardomurri)\
**Replies:** 2\
**Last updated:** [March 14, 2020, 3:52pm UTC](https://discourse.julialang.org/t/convex-jl-variables-disappearing-in-cumulative-constraint/35958 "2020-03-14T15:52:04Z")

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Hello, I am trying to build a sort of L\_2-norm constraint piecewise, using code like this (simplified form of the actual code): x = \[Convex.Variable(m\*s+2r, m\*s+2r) for \_ in 1:N\]; for t in 1:N @debug "…

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## [Possible bug while calculating determinant?](https://discourse.julialang.org/t/possible-bug-while-calculating-determinant/35960)

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**Author:** [@PseudoCodeNerd](https://discourse.julialang.org/u/PseudoCodeNerd)\
**Replies:** 8\
**Last updated:** [March 14, 2020, 3:46pm UTC](https://discourse.julialang.org/t/possible-bug-while-calculating-determinant/35960 "2020-03-14T15:46:47Z")

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Hello I’m a high school junior and was recently self-studying linear algebra. I was reading about calculating determinants and the properties of them. I read that whenever in a determinant, there are 2 similar rows (or…

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## [Alternative to Data Voyager for Julia](https://discourse.julialang.org/t/alternative-to-data-voyager-for-julia/35946)

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**Author:** [@Usor](https://discourse.julialang.org/u/Usor)\
**Replies:** 3\
**Last updated:** [March 14, 2020, 12:25pm UTC](https://discourse.julialang.org/t/alternative-to-data-voyager-for-julia/35946 "2020-03-14T12:25:01Z")

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Is Data Voyager (.jl), a beautiful package, the only one of its kind for Julia? Is there another such system?

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## [VegaLite: Facet plot with errorband](https://discourse.julialang.org/t/vegalite-facet-plot-with-errorband/35903)

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**Author:** [@hellemo](https://discourse.julialang.org/u/hellemo)\
**Replies:** 4\
**Last updated:** [March 13, 2020, 4:55pm UTC](https://discourse.julialang.org/t/vegalite-facet-plot-with-errorband/35903 "2020-03-13T16:55:13Z")

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Does VegaLite not support faceting of plots with errorbands? I’m struggling to make this work: using VegaLite, DataFrames function generatedata() df = DataFrame() K = 10 L = 10 Cat1 = \[:A,:B\] Cat2 =…

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## [Help understanding GLM (the concept, not the package)](https://discourse.julialang.org/t/help-understanding-glm-the-concept-not-the-package/35896)

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**Author:** [@mthelm85](https://discourse.julialang.org/u/mthelm85)\
**Replies:** 4\
**Last updated:** [March 13, 2020, 3:56pm UTC](https://discourse.julialang.org/t/help-understanding-glm-the-concept-not-the-package/35896 "2020-03-13T15:56:23Z")

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I’m trying to understand how generalized linear models work by coding a simple example from scratch and I’m hoping some of the stats experts here (I know there are several of you lurking around :face\_with\_monocle:) can h…

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## [CuArrays warning: You are using CUDNN 7.1.4 for CUDA 9.0.0 with CUDA toolkit 9.2.148; these might be incompatible](https://discourse.julialang.org/t/cuarrays-warning-you-are-using-cudnn-7-1-4-for-cuda-9-0-0-with-cuda-toolkit-9-2-148-these-might-be-incompatible/35891)

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**Author:** [@Phil\_Tomson](https://discourse.julialang.org/u/Phil_Tomson)\
**Replies:** 4\
**Last updated:** [March 13, 2020, 3:23pm UTC](https://discourse.julialang.org/t/cuarrays-warning-you-are-using-cudnn-7-1-4-for-cuda-9-0-0-with-cuda-toolkit-9-2-148-these-might-be-incompatible/35891 "2020-03-13T15:23:22Z")

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I was trying to run the Flux modelzoo MNIST mlp.jl example and I notice these warning coming from CuArrays.jl: julia\> include("mlp.jl") \[ Info: Precompiling Flux \[587475ba-b771-5e3f-ad9e-33799f191a9c\] ┌ Warning: CuArray…

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## [Can not install CUDAnative](https://discourse.julialang.org/t/can-not-install-cudanative/35925)

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**Author:** [@sbacelar](https://discourse.julialang.org/u/sbacelar)\
**Replies:** 2\
**Last updated:** [March 13, 2020, 1:30pm UTC](https://discourse.julialang.org/t/can-not-install-cudanative/35925 "2020-03-13T13:30:36Z")

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GPU newbie here (Julia 1.3.1 and Windows 10). I have been able to install CUDAdrv v6.1.0 but when I try to install CUDAnative (and also CuArrays) I receive the following error: (v1.3) pkg\> add CUDAnative Resolving pack…

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## [Convex.jl: How to print full variable ID](https://discourse.julialang.org/t/convex-jl-how-to-print-full-variable-id/35917)

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**Author:** [@riccardomurri](https://discourse.julialang.org/u/riccardomurri)\
**Replies:** 1\
**Last updated:** [March 13, 2020, 9:50am UTC](https://discourse.julialang.org/t/convex-jl-how-to-print-full-variable-id/35917 "2020-03-13T09:50:14Z")

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I’m trying to debug an issue with the formulation of an optimization problem using Convex.jl, and I got the following tree print of a constraint (using Convex.MAXDEPTH\[\] = 12 and Convex.MAXWIDTH\[\] = 120), but all the “…

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## [Speeding up MCMC for logistic regression with large datasets using Turing or some alternative](https://discourse.julialang.org/t/speeding-up-mcmc-for-logistic-regression-with-large-datasets-using-turing-or-some-alternative/35838)

<div class="topic-metadata">

**Author:** [@HarrisonWilde](https://discourse.julialang.org/u/HarrisonWilde)\
**Replies:** 2\
**Last updated:** [March 12, 2020, 5:58pm UTC](https://discourse.julialang.org/t/speeding-up-mcmc-for-logistic-regression-with-large-datasets-using-turing-or-some-alternative/35838 "2020-03-12T17:58:19Z")

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Hi, I am running some logistic regression MCMC sampling chains using Turing and wondering how best to optimise / use multiprocessing etc. to get maximum performance. My code currently looks like this: function get\_condi…

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## [How to make compact subset queries of a dataframe?](https://discourse.julialang.org/t/how-to-make-compact-subset-queries-of-a-dataframe/35883)

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**Author:** [@HenriDeh](https://discourse.julialang.org/u/HenriDeh)\
**Replies:** 5\
**Last updated:** [March 12, 2020, 5:10pm UTC](https://discourse.julialang.org/t/how-to-make-compact-subset-queries-of-a-dataframe/35883 "2020-03-12T17:10:04Z")

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I am looking for a more elegant way to do this data\[(data.ID .== 1) .| (data.ID .== 4) .| (data.ID .== 7) .| (data.ID .== 10),: \] where data is a DataFrame. I simply want to extract rows where the ID value is one of th…

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## [What type of optimization problem is this?](https://discourse.julialang.org/t/what-type-of-optimization-problem-is-this/35882)

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**Author:** [@marcus](https://discourse.julialang.org/u/marcus)\
**Replies:** 5\
**Last updated:** [March 12, 2020, 4:25pm UTC](https://discourse.julialang.org/t/what-type-of-optimization-problem-is-this/35882 "2020-03-12T16:25:20Z")

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Hi all. I have a constrained optimization problem which looks like it might belong to a known class. The problem is to maximize the quotient \\dfrac{x^T A x}{x^T B x} w.r.t real vector x, subject to the constraint x^T x …

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## [Does Ipopt have the option to do numerical derivatives for non-differentiable function?](https://discourse.julialang.org/t/does-ipopt-have-the-option-to-do-numerical-derivatives-for-non-differentiable-function/35887)

<div class="topic-metadata">

**Author:** [@zxjroger](https://discourse.julialang.org/u/zxjroger)\
**Replies:** 0\
**Last updated:** [March 12, 2020, 3:56pm UTC](https://discourse.julialang.org/t/does-ipopt-have-the-option-to-do-numerical-derivatives-for-non-differentiable-function/35887 "2020-03-12T15:56:26Z")

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I am trying to compare different solvers/routines on minimizing the objective function of simulated method of moments. This objective function is non-differentiable. I wonder if there is a setting in Ipopt to do numerica…

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## [Deleting edges from SimpleWeightedDiGraph based on edge weight](https://discourse.julialang.org/t/deleting-edges-from-simpleweighteddigraph-based-on-edge-weight/35835)

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**Author:** [@Jakob](https://discourse.julialang.org/u/Jakob)\
**Replies:** 4\
**Last updated:** [March 12, 2020, 3:27pm UTC](https://discourse.julialang.org/t/deleting-edges-from-simpleweighteddigraph-based-on-edge-weight/35835 "2020-03-12T15:27:49Z")

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Hi, i would like to remove multiple edges from a SimpleWeightedDiGraph based on their weight. However, naively looping over edges as in the example below does not yield the desired result, presumably because the intern…

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## [Using Blink, Interact and PlotyJS together](https://discourse.julialang.org/t/using-blink-interact-and-plotyjs-together/29241)

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**Author:** [@amit112amit](https://discourse.julialang.org/u/amit112amit)\
**Replies:** 2\
**Last updated:** [March 12, 2020, 1:19pm UTC](https://discourse.julialang.org/t/using-blink-interact-and-plotyjs-together/29241 "2020-03-12T13:19:39Z")

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Hi. As far as I could find, we cannot use Interact.@manipulate with PlotlyJS in a Jupyterlab notebook to make interactive plots. I was able to use GR and PyPlot but I prefer using PlotlyJS because it allows me to update…

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## [Spherical Harmonic transforms using Julia](https://discourse.julialang.org/t/spherical-harmonic-transforms-using-julia/35824)

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**Author:** [@SMH](https://discourse.julialang.org/u/SMH)\
**Replies:** 4\
**Last updated:** [March 12, 2020, 11:37am UTC](https://discourse.julialang.org/t/spherical-harmonic-transforms-using-julia/35824 "2020-03-12T11:37:32Z")

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Hello, I want to compute forward and inverse spherical harmonic transforms in Julia. I tried using FastTransforms but the package appears to be unstable (on the Mac Desktop, at any rate) and I also can’t seem to control…

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## [Note: Job post specifically relevant to the GEO domain](https://discourse.julialang.org/t/note-job-post-specifically-relevant-to-the-geo-domain/35877)

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**Author:** [@mafla](https://discourse.julialang.org/u/mafla)\
**Replies:** 0\
**Last updated:** [March 12, 2020, 11:34am UTC](https://discourse.julialang.org/t/note-job-post-specifically-relevant-to-the-geo-domain/35877 "2020-03-12T11:34:28Z")

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