# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?page=477

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**Page:** 478

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## [For syntax in @constraints](https://discourse.julialang.org/t/for-syntax-in-constraints/30483)

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**Author:** [@leclere](https://discourse.julialang.org/u/leclere)\
**Replies:** 1\
**Last updated:** [October 30, 2019, 1:28pm UTC](https://discourse.julialang.org/t/for-syntax-in-constraints/30483 "2019-10-30T13:28:48Z")

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Hi! I am looking for the most elegant way of adding multiple constraints (e.g. with a for loop) in a JuMP model. For example I would like to be able to write : using JuMP m = Model() @variable(m,x\[1:5\]) @constraints(…

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## [We can write an optimized BLAS library in pure Julia (please skip OP and jump to post 4)](https://discourse.julialang.org/t/we-can-write-an-optimized-blas-library-in-pure-julia-please-skip-op-and-jump-to-post-4/11634)

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**Author:** [@Elrod](https://discourse.julialang.org/u/Elrod)\
**Replies:** 17\
**Last updated:** [October 30, 2019, 9:46am UTC](https://discourse.julialang.org/t/we-can-write-an-optimized-blas-library-in-pure-julia-please-skip-op-and-jump-to-post-4/11634 "2019-10-30T09:46:31Z")

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There’s a readme with a lot of output dumped on it here: https://github.com/chriselrod/TriangularMatrices.jl But the highlights are that, I found an fairly optimal “compute kernel” (at least for my architecture on Jul…

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## [ApproxFun.jl Convolution/Fourier Multiplier](https://discourse.julialang.org/t/approxfun-jl-convolution-fourier-multiplier/30280)

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**Author:** [@cpross90](https://discourse.julialang.org/u/cpross90)\
**Replies:** 11\
**Last updated:** [October 30, 2019, 7:20am UTC](https://discourse.julialang.org/t/approxfun-jl-convolution-fourier-multiplier/30280 "2019-10-30T07:20:16Z")

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I’m trying to implement a solver for the Benjamin-Ono equation using DifferentialEquations.jl. I have periodic boundary conditions, so I’m using ApproxFun.jl to take the Fourier transform and use the method of lines to s…

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## [Newbie Question: Julia optimization multiprocessing](https://discourse.julialang.org/t/newbie-question-julia-optimization-multiprocessing/1686)

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**Author:** [@Jason](https://discourse.julialang.org/u/Jason)\
**Replies:** 10\
**Last updated:** [October 30, 2019, 1:12am UTC](https://discourse.julialang.org/t/newbie-question-julia-optimization-multiprocessing/1686 "2019-10-30T01:12:17Z")

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Hi, I’m trying to figure out whether Julia is a good language for a project I’m undertaking. One thing I’ll need to do is optimize a complex statistical function (Hidden Markov / CRF related) involving potentially 12K p…

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## [3D variable in JuMP](https://discourse.julialang.org/t/3d-variable-in-jump/30416)

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**Author:** [@g001234](https://discourse.julialang.org/u/g001234)\
**Replies:** 4\
**Last updated:** [October 29, 2019, 11:45pm UTC](https://discourse.julialang.org/t/3d-variable-in-jump/30416 "2019-10-29T23:45:04Z")

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I am working on a convex optimization problem that needs to define several (e.g. 5) symmetric matrices as variables. I was wondering if it is possible to define those variables with a single line like @variable(m, x(N,N,…

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## [Save the date: 4th annual JuMP-dev](https://discourse.julialang.org/t/save-the-date-4th-annual-jump-dev/30465)

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**Author:** [@odow](https://discourse.julialang.org/u/odow)\
**Replies:** 0\
**Last updated:** [October 29, 2019, 10:20pm UTC](https://discourse.julialang.org/t/save-the-date-4th-annual-jump-dev/30465 "2019-10-29T22:20:37Z")

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Dear all, We are pleased to announce that the 4th annual JuMP-dev workshop will be held June 15-17 2020 in Louvain-la-Neuve, Belgium, in conjunction with UCLouvain. Further details, including a call for speakers, will …

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## [Getting error while using CurricularAnalytics](https://discourse.julialang.org/t/getting-error-while-using-curricularanalytics/30389)

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**Author:** [@Gaurav\_Sharma](https://discourse.julialang.org/u/Gaurav_Sharma)\
**Replies:** 2\
**Last updated:** [October 29, 2019, 6:55pm UTC](https://discourse.julialang.org/t/getting-error-while-using-curricularanalytics/30389 "2019-10-29T18:55:43Z")

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Version of Julia: “1.3.0-rc4.1” CurricularAnalytics v0.6.0 “”" import Pkg Pkg.add(“CurricularAnalytics”) using CurricularAnalytics Info: Precompiling CurricularAnalytics \[593ffa3d-269e-5d81-88bc-c3b6809c35a6\] └ @ …

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## [Problem with the positivedefinitivenesse of a kernel matrix](https://discourse.julialang.org/t/problem-with-the-positivedefinitivenesse-of-a-kernel-matrix/28976)

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**Author:** [@Ujku\_KU](https://discourse.julialang.org/u/Ujku_KU)\
**Replies:** 8\
**Last updated:** [October 29, 2019, 2:37pm UTC](https://discourse.julialang.org/t/problem-with-the-positivedefinitivenesse-of-a-kernel-matrix/28976 "2019-10-29T14:37:51Z")

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Hi guys, I am trying to generate a positive definite kernel matrix. Below is the minimalistic code: julia\> using MultivariateStats, ForwardDiff, StatsBase, MLKernels, LinearAlgebra, Optim, Plots, Distributions, Forwar…

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## [JuMP macro @constraint where variable is in a finite set](https://discourse.julialang.org/t/jump-macro-constraint-where-variable-is-in-a-finite-set/30417)

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**Author:** [@dadada\_dadada](https://discourse.julialang.org/u/dadada_dadada)\
**Replies:** 1\
**Last updated:** [October 28, 2019, 8:23pm UTC](https://discourse.julialang.org/t/jump-macro-constraint-where-variable-is-in-a-finite-set/30417 "2019-10-28T20:23:02Z")

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Is it possible? I’m trying to solve a very simple optimization problem with IPOPT where the variables are binary. But it seems that IPOPT doesn’t support Bin variables, only continuous ones. Would it be possible to cre…

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## [(Interval) subset optimization with JuMP](https://discourse.julialang.org/t/interval-subset-optimization-with-jump/30415)

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**Author:** [@joemiller](https://discourse.julialang.org/u/joemiller)\
**Replies:** 2\
**Last updated:** [October 28, 2019, 7:50pm UTC](https://discourse.julialang.org/t/interval-subset-optimization-with-jump/30415 "2019-10-28T19:50:01Z")

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Hey everyone. I’m trying to figure out how to use JuMP to optimize a function of a slice of data over the left and right endpoints for the range. I’ve never used JuMP before so I’m piecing this together from tutorials a…

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## [NCP-function implementation (ifelse)](https://discourse.julialang.org/t/ncp-function-implementation-ifelse/30411)

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**Author:** [@SingingKim](https://discourse.julialang.org/u/SingingKim)\
**Replies:** 3\
**Last updated:** [October 28, 2019, 7:28pm UTC](https://discourse.julialang.org/t/ncp-function-implementation-ifelse/30411 "2019-10-28T19:28:46Z")

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Hi, I’m trying to implement a model with constraints based on an NCP-function (continuous & differentiable) and put it into an NLP solver such as IPOPT: @constraint(m, f(x,y) \<= 0) where f(x,y) := xy if …

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## [Optim.jl: bracketing with Newton()](https://discourse.julialang.org/t/optim-jl-bracketing-with-newton/30332)

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**Author:** [@PharmCat](https://discourse.julialang.org/u/PharmCat)\
**Replies:** 9\
**Last updated:** [October 28, 2019, 2:54pm UTC](https://discourse.julialang.org/t/optim-jl-bracketing-with-newton/30332 "2019-10-28T14:54:20Z")

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Is it possible to use Newton() methods with limiting some variables? Like FMinbox?

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## [Extract alignments from BAM and associated FASTA reference genome](https://discourse.julialang.org/t/extract-alignments-from-bam-and-associated-fasta-reference-genome/30294)

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**Author:** [@Gio](https://discourse.julialang.org/u/Gio)\
**Replies:** 2\
**Last updated:** [October 28, 2019, 11:49am UTC](https://discourse.julialang.org/t/extract-alignments-from-bam-and-associated-fasta-reference-genome/30294 "2019-10-28T11:49:10Z")

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Hello everybody, I’m new to Julia/BioJulia but I’m already appreciating some features of both the language and the Bio libraries (really nice work!). I’m currently trying to do simple stuff to get acquainted with the Bi…

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## [Fast calculation of eigenvalues](https://discourse.julialang.org/t/fast-calculation-of-eigenvalues/30359)

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**Author:** [@FujiwaraTakumiEH](https://discourse.julialang.org/u/FujiwaraTakumiEH)\
**Replies:** 6\
**Last updated:** [October 28, 2019, 1:24am UTC](https://discourse.julialang.org/t/fast-calculation-of-eigenvalues/30359 "2019-10-28T01:24:10Z")

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Background: Now I have a symmetric matrix A. I need to find the first n eigenvalues and eigenvectors. (I have not actually started to write code, but in the algorithm process I observed the need to solve the eigenvalues …

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## [Quadratic Expression](https://discourse.julialang.org/t/quadratic-expression/30337)

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**Author:** [@Nikos-Atzarakis](https://discourse.julialang.org/u/Nikos-Atzarakis)\
**Replies:** 2\
**Last updated:** [October 27, 2019, 12:49pm UTC](https://discourse.julialang.org/t/quadratic-expression/30337 "2019-10-27T12:49:46Z")

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Hi, I’m trying to create a quadratic expression using a variable attached in model m : using JuMP using Ipopt m= Model(with\_optimizer(Ipopt.Optimizer)) @variables m begin u\[1:(time\_lapses)\*2,1:number\_of\_players\] …

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## [Example of Login to SAML/Shibboleth authenticated site?](https://discourse.julialang.org/t/example-of-login-to-saml-shibboleth-authenticated-site/30361)

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**Author:** [@robertfeldt](https://discourse.julialang.org/u/robertfeldt)\
**Replies:** 1\
**Last updated:** [October 27, 2019, 12:39pm UTC](https://discourse.julialang.org/t/example-of-login-to-saml-shibboleth-authenticated-site/30361 "2019-10-27T12:39:29Z")

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Anyone has been able to (programmatically) authenticate via SAML/Shibboleth from/with Julia? I’m successfully scraping information from a site but to get all the information I need they require single-sign on via a SAML/…

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## [Monte Carlo Simulation for Investment Portfolio Earnings](https://discourse.julialang.org/t/monte-carlo-simulation-for-investment-portfolio-earnings/30354)

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**Author:** [@Nigel\_Adams](https://discourse.julialang.org/u/Nigel_Adams)\
**Replies:** 0\
**Last updated:** [October 27, 2019, 5:07am UTC](https://discourse.julialang.org/t/monte-carlo-simulation-for-investment-portfolio-earnings/30354 "2019-10-27T05:07:47Z")

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In case anyone is interested in Monte Carlo finance experiments this might be of interest. In this blog post we use Julia to simulate the growth of an investment portfolio using Geometric Brownian motion (GBM). I hope…

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## [Extend Axes](https://discourse.julialang.org/t/extend-axes/30340)

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**Author:** [@squirrel](https://discourse.julialang.org/u/squirrel)\
**Replies:** 1\
**Last updated:** [October 26, 2019, 6:47pm UTC](https://discourse.julialang.org/t/extend-axes/30340 "2019-10-26T18:47:32Z")

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Hi. I have a function I want to graph whose domain is only 0 to infinity, but I want the plot to show the negative x axis, too. How do I tell it to do this? Right now I have: using Plots x(u) = u y(u) = sqrt(u) y2(u…

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## [How to add metadata info to a DataFrame?](https://discourse.julialang.org/t/how-to-add-metadata-info-to-a-dataframe/11168)

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**Author:** [@gcalderone](https://discourse.julialang.org/u/gcalderone)\
**Replies:** 96\
**Last updated:** [October 26, 2019, 2:57am UTC](https://discourse.julialang.org/t/how-to-add-metadata-info-to-a-dataframe/11168 "2019-10-26T02:57:26Z")

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Storing both data and metadata in the same object or container is a very common approach in many research fields, and it has proven to be very successful in (for instance) astronomy where a few standards had been officia…

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## [The objective function \`Val{false}()\` is not supported by JuMP](https://discourse.julialang.org/t/the-objective-function-val-false-is-not-supported-by-jump/30296)

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**Author:** [@NextMyth](https://discourse.julialang.org/u/NextMyth)\
**Replies:** 2\
**Last updated:** [October 25, 2019, 10:03pm UTC](https://discourse.julialang.org/t/the-objective-function-val-false-is-not-supported-by-jump/30296 "2019-10-25T22:03:39Z")

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Hi, I am trying to build a NHL DFS lineup optimizer using code found at https://github.com/dscotthunter/Fantasy-Hockey-IP-Code/blob/master/code\_for\_Github.jl which needs updated for the current version of JuMP. I’m very …

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## [\[DIP\] K-means and Super pixels](https://discourse.julialang.org/t/dip-k-means-and-super-pixels/30243)

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**Author:** [@apattyn](https://discourse.julialang.org/u/apattyn)\
**Replies:** 4\
**Last updated:** [October 25, 2019, 9:30pm UTC](https://discourse.julialang.org/t/dip-k-means-and-super-pixels/30243 "2019-10-25T21:30:32Z")

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Hey everyone. I saw julia has the libraries Clustering.jl and ImageSegmentation.jl for data segmentation. I was mainly looking to do some grayscale image segmentation and I am not seeing k-means for images (e.g. K-means …

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## [Tables.jl win!](https://discourse.julialang.org/t/tables-jl-win/30312)

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**Author:** [@jkbest2](https://discourse.julialang.org/u/jkbest2)\
**Replies:** 0\
**Last updated:** [October 25, 2019, 5:45pm UTC](https://discourse.julialang.org/t/tables-jl-win/30312 "2019-10-25T17:45:48Z")

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One of my projects (originally written in the v0.6 days) generates a Vector of structs as its output. In the past I would’ve converted it to a DataFrame or similar with a lot of getfield broadcasts, but I was delighted t…

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## [Strange bug when truncating BigFloat to UInt8](https://discourse.julialang.org/t/strange-bug-when-truncating-bigfloat-to-uint8/30301)

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**Author:** [@gmouts](https://discourse.julialang.org/u/gmouts)\
**Replies:** 11\
**Last updated:** [October 25, 2019, 3:11pm UTC](https://discourse.julialang.org/t/strange-bug-when-truncating-bigfloat-to-uint8/30301 "2019-10-25T15:11:18Z")

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I am playing a bit with ridiculously big floating point numbers. The following: setprecision(8640) tf = BigFloat(255.11254081778609618826079023493869737962406296545795414517402744704859236140966993143901247046399018605…

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## [How to graphically solve a problem?](https://discourse.julialang.org/t/how-to-graphically-solve-a-problem/30231)

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**Author:** [@RaquelSantos](https://discourse.julialang.org/u/RaquelSantos)\
**Replies:** 1\
**Last updated:** [October 25, 2019, 9:53am UTC](https://discourse.julialang.org/t/how-to-graphically-solve-a-problem/30231 "2019-10-25T09:53:59Z")

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Is it possible to get the graphical solution of the x1 and x2 result of this problem using the Pyplot package? using JuMP, Cbc using PyPlot Test1 = Model(solver = CbcSolver()) @variable(Test1, x1 \>= 0) @variable(Test…

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## [Plan of a gallery of fractal-related pattern animations with JuliaLang](https://discourse.julialang.org/t/plan-of-a-gallery-of-fractal-related-pattern-animations-with-julialang/30282)

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**Author:** [@HaoLi111](https://discourse.julialang.org/u/HaoLi111)\
**Replies:** 1\
**Last updated:** [October 25, 2019, 3:48am UTC](https://discourse.julialang.org/t/plan-of-a-gallery-of-fractal-related-pattern-animations-with-julialang/30282 "2019-10-25T03:48:54Z")

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With JuliaLang’s fast computing and plotting ecosystems, I decide to render some fractal patterns, and at first I tried some pedestrian example in larger scales, and tried to customize with my own taste in aesthetics. G…

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## [Encrypted streams](https://discourse.julialang.org/t/encrypted-streams/30187)

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**Author:** [@Janis\_Erdmanis](https://discourse.julialang.org/u/Janis_Erdmanis)\
**Replies:** 3\
**Last updated:** [October 24, 2019, 8:54pm UTC](https://discourse.julialang.org/t/encrypted-streams/30187 "2019-10-24T20:54:54Z")

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Does Julia already have a library which can encrypt streams with a symmetric key? What I need is something simple as: using Sockets server = listen() socket = accept(server) # Some arbitrary key exchange protocol. For …

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## [Julia-Gumbo-webscraping](https://discourse.julialang.org/t/julia-gumbo-webscraping/30203)

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**Author:** [@Anil\_Mathews](https://discourse.julialang.org/u/Anil_Mathews)\
**Replies:** 16\
**Last updated:** [October 24, 2019, 1:54pm UTC](https://discourse.julialang.org/t/julia-gumbo-webscraping/30203 "2019-10-24T13:54:16Z")

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Is it possible to convert structure type to julia string type. i have scraped some data from website with Gumbo.jl and i want to push this data to a Array but when i do that i get this error:Cannot convert an object of …

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## [Mosek and Convex.jl -- Still not working](https://discourse.julialang.org/t/mosek-and-convex-jl-still-not-working/30254)

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**Author:** [@raktim](https://discourse.julialang.org/u/raktim)\
**Replies:** 3\
**Last updated:** [October 24, 2019, 1:33pm UTC](https://discourse.julialang.org/t/mosek-and-convex-jl-still-not-working/30254 "2019-10-24T13:33:12Z")

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I have been trying to use Convex with Mosek, but it seems there are still some errors. I have been trying to solve the following examples problem: using Convex, Mosek m = 4; n = 5 A = randn(m, n); b = randn(m, 1) x…

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## [Did anyone thought of implementing Octave on top of Julia?](https://discourse.julialang.org/t/did-anyone-thought-of-implementing-octave-on-top-of-julia/30211)

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**Author:** [@XVilka](https://discourse.julialang.org/u/XVilka)\
**Replies:** 3\
**Last updated:** [October 23, 2019, 11:35am UTC](https://discourse.julialang.org/t/did-anyone-thought-of-implementing-octave-on-top-of-julia/30211 "2019-10-23T11:35:40Z")

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Apparently, a lot of the Octave/MATLAB features are already available in Julia, and implementing Octave language interpreter would allow to save a lot of time for both worlds. So basically, it will boil down to implement…

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## [How to exclude the columns of a matrix which are present as columns in another matrix](https://discourse.julialang.org/t/how-to-exclude-the-columns-of-a-matrix-which-are-present-as-columns-in-another-matrix/30206)

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**Author:** [@Ujku\_KU](https://discourse.julialang.org/u/Ujku_KU)\
**Replies:** 2\
**Last updated:** [October 23, 2019, 8:30am UTC](https://discourse.julialang.org/t/how-to-exclude-the-columns-of-a-matrix-which-are-present-as-columns-in-another-matrix/30206 "2019-10-23T08:30:05Z")

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Hi guys, is there any existing function/method in Julia which checks if the columns of a matrix are columns of another matrix, and remove them from one of the matrices in case there is a positive outcome? Thank you ver…

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