# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1895

[Latest](https://discourse.julialang.org/latest.md) · [Categories](https://discourse.julialang.org/categories.md) · [Tags](https://discourse.julialang.org/tags.md)

**Page:** 1896

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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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## [Vector of monomials of order up to n?](https://discourse.julialang.org/t/vector-of-monomials-of-order-up-to-n/30308)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 3\
**Last updated:** [October 25, 2019, 5:41pm UTC](https://discourse.julialang.org/t/vector-of-monomials-of-order-up-to-n/30308 "2019-10-25T17:41:41Z")

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Suppose I have a scalar x. Then producing the vector \[1,x,x^2, \\ldots,x^n\] is straightforward, \[x^i for i in 0:n\] What if x is a vector, x=\[x\_1,\\dots,x\_{n\_x}\], and I want to produce the vector \[1, x\_1, \\ldots,x\_{n\_x}, …

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## [Understanding while loop UndedVarError and scope](https://discourse.julialang.org/t/understanding-while-loop-undedvarerror-and-scope/16609)

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**Author:** [@Vic](https://discourse.julialang.org/u/Vic)\
**Replies:** 28\
**Last updated:** [October 25, 2019, 5:14pm UTC](https://discourse.julialang.org/t/understanding-while-loop-undedvarerror-and-scope/16609 "2019-10-25T17:14:36Z")

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REPL, Julia v1.0.1: julia\> a=1; julia\> while true; print(a); break; end 1 julia\> while true; a=2; break; end julia\> while true; a=2; print(a); break; end 2 julia\> while true; print(a); a=…

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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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## [Quantitative Investing Associate at Betterment](https://discourse.julialang.org/t/quantitative-investing-associate-at-betterment/30309)

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**Author:** [@Sebastian\_Rollen](https://discourse.julialang.org/u/Sebastian_Rollen)\
**Replies:** 0\
**Last updated:** [October 25, 2019, 3:09pm UTC](https://discourse.julialang.org/t/quantitative-investing-associate-at-betterment/30309 "2019-10-25T15:09:56Z")

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The Investing team at Betterment is hiring for the Quantitative Investing Associate role in New York. One of our big initiatives over the past year (and next year, too) is using Julia to bridge the two-language gap betwe…

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## [Why is Atom with Juno so slow?](https://discourse.julialang.org/t/why-is-atom-with-juno-so-slow/30293)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 18\
**Last updated:** [October 25, 2019, 2:34pm UTC](https://discourse.julialang.org/t/why-is-atom-with-juno-so-slow/30293 "2019-10-25T14:34:44Z")

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I think at this point I could not recommend Atom with Juno for demoing Julia. The time delays are enormous. Would it be possible to figure out where this happens and fix it? Perhaps this might help to illustrate my poin…

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## [What's the problem presented by the Anti-malwares](https://discourse.julialang.org/t/whats-the-problem-presented-by-the-anti-malwares/30303)

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**Author:** [@Yan](https://discourse.julialang.org/u/Yan)\
**Replies:** 3\
**Last updated:** [October 25, 2019, 2:28pm UTC](https://discourse.julialang.org/t/whats-the-problem-presented-by-the-anti-malwares/30303 "2019-10-25T14:28:50Z")

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## [What is the relation between cropping a .osm file by osmium cat and the crop! function provided in OpenStreetMapX package?](https://discourse.julialang.org/t/what-is-the-relation-between-cropping-a-osm-file-by-osmium-cat-and-the-crop-function-provided-in-openstreetmapx-package/30210)

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**Author:** [@bsnyh](https://discourse.julialang.org/u/bsnyh)\
**Replies:** 6\
**Last updated:** [October 25, 2019, 1:44pm UTC](https://discourse.julialang.org/t/what-is-the-relation-between-cropping-a-osm-file-by-osmium-cat-and-the-crop-function-provided-in-openstreetmapx-package/30210 "2019-10-25T13:44:34Z")

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I’m confused by the two cropping operations as mentioned in the title. My goal is to obtain the roadnetwork of a certain area using open street map data. Reference link: What's the general algorithm to draw a road netwo…

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## [Video tutorial: Julia REPL tips and tricks](https://discourse.julialang.org/t/video-tutorial-julia-repl-tips-and-tricks/29913)

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**Author:** [@miguelraz](https://discourse.julialang.org/u/miguelraz)\
**Replies:** 5\
**Last updated:** [October 25, 2019, 9:56am UTC](https://discourse.julialang.org/t/video-tutorial-julia-repl-tips-and-tricks/29913 "2019-10-25T09:56:14Z")

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Hello all! I recently recorded a video tutorial on some cool/neat/quality of life tips and tricks for getting the most out of the Julia REPL. The point is to be learning in the open and bringing others along. There’s …

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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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## [From "UndefVarError", a hopefully funny intro to Scoping](https://discourse.julialang.org/t/from-undefvarerror-a-hopefully-funny-intro-to-scoping/30285)

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**Author:** [@HaoLi111](https://discourse.julialang.org/u/HaoLi111)\
**Replies:** 4\
**Last updated:** [October 25, 2019, 9:10am UTC](https://discourse.julialang.org/t/from-undefvarerror-a-hopefully-funny-intro-to-scoping/30285 "2019-10-25T09:10:11Z")

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This is a translation version of the post from by myself. Hope it’s not too boring. First I declare that “Julia” refers to the language and is not associated with any person. The lost toy - the “UndefVarError” If one …

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## [Connecting Juno to work with Julia installed on a remote server](https://discourse.julialang.org/t/connecting-juno-to-work-with-julia-installed-on-a-remote-server/7494)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 22\
**Last updated:** [October 25, 2019, 8:46am UTC](https://discourse.julialang.org/t/connecting-juno-to-work-with-julia-installed-on-a-remote-server/7494 "2019-10-25T08:46:59Z")

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Hello, I am trying to work with Juno using Julia installed on a powerful server, for which I have SSH (and a not-default port let’s call it #SPORT). I am trying to follow the documentation at http://docs.junolab.org/la…

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## [Got route distance 0 between two different GPS locations?](https://discourse.julialang.org/t/got-route-distance-0-between-two-different-gps-locations/30291)

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**Author:** [@bsnyh](https://discourse.julialang.org/u/bsnyh)\
**Replies:** 0\
**Last updated:** [October 25, 2019, 7:25am UTC](https://discourse.julialang.org/t/got-route-distance-0-between-two-different-gps-locations/30291 "2019-10-25T07:25:44Z")

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I have two longitude, latitude pairs in coding, which are randomly generated as the following. location 1: (39.655994758358524, 56.54323616733745) location 2: (32.44297771882851, 68.10900336760139) I need to calculate…

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## [Help with parallel computing for a simple loop with a large function](https://discourse.julialang.org/t/help-with-parallel-computing-for-a-simple-loop-with-a-large-function/30258)

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**Author:** [@drez](https://discourse.julialang.org/u/drez)\
**Replies:** 4\
**Last updated:** [October 25, 2019, 4:08am UTC](https://discourse.julialang.org/t/help-with-parallel-computing-for-a-simple-loop-with-a-large-function/30258 "2019-10-25T04:08:48Z")

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Hi, I am relatively new to and wish to implement parallel computing in my code. Currently, I have a code with a large function f(x) within a loop. For example, for i = 1:N a\[ i \] = f(x\[ i \]) end ... ... C = C + …

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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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## [Convert string of type/eltype to Type itself](https://discourse.julialang.org/t/convert-string-of-type-eltype-to-type-itself/30238)

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**Author:** [@FredC](https://discourse.julialang.org/u/FredC)\
**Replies:** 14\
**Last updated:** [October 25, 2019, 12:22am UTC](https://discourse.julialang.org/t/convert-string-of-type-eltype-to-type-itself/30238 "2019-10-25T00:22:47Z")

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I have an Array{String,1} which I want to convert into an array of data types to use with loadnsparse in JuliaDB. There appears to be no way to convert a string such as “Union{Missing, Int64}” into the obvious type?

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## [How do I write an array of Int8 to disk exactly](https://discourse.julialang.org/t/how-do-i-write-an-array-of-int8-to-disk-exactly/30143)

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**Author:** [@gmouts](https://discourse.julialang.org/u/gmouts)\
**Replies:** 3\
**Last updated:** [October 24, 2019, 11:11pm UTC](https://discourse.julialang.org/t/how-do-i-write-an-array-of-int8-to-disk-exactly/30143 "2019-10-24T23:11:33Z")

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I want to create a file that on the disk is exactly the value of a given arrayof UInt8. Say I have generated a arrayof length n and I gave it the name seq. Does the following do what I want? f = open("filename",w) wri…

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## [JuliaDB loadndsparse: many errors](https://discourse.julialang.org/t/juliadb-loadndsparse-many-errors/30249)

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**Author:** [@FredC](https://discourse.julialang.org/u/FredC)\
**Replies:** 15\
**Last updated:** [October 24, 2019, 11:07pm UTC](https://discourse.julialang.org/t/juliadb-loadndsparse-many-errors/30249 "2019-10-24T23:07:27Z")

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I’ve done a fair amount of work to get my CSV cleaned up (pipe-delimited/no quotes), data types and column names right and loaded separate, consulted the out-of-core section of the JuliaDB docs, and I found the TrueFX Ju…

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## [ERROR: UndefRefError: access to undefined reference in debug mode](https://discourse.julialang.org/t/error-undefreferror-access-to-undefined-reference-in-debug-mode/29271)

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**Author:** [@Iulian.Cioarca](https://discourse.julialang.org/u/Iulian.Cioarca)\
**Replies:** 3\
**Last updated:** [October 24, 2019, 10:30pm UTC](https://discourse.julialang.org/t/error-undefreferror-access-to-undefined-reference-in-debug-mode/29271 "2019-10-24T22:30:01Z")

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Usually when I debug code using JuliaInterpreter I can see the variables from the current scope in the workspace and I can also use them in the REPL (to evaluate certain expressions). I wanted to run the code from: http…

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## [Error when adding packages in Julia 1.3 rc04 on Windows](https://discourse.julialang.org/t/error-when-adding-packages-in-julia-1-3-rc04-on-windows/30276)

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**Author:** [@Iulian.Cioarca](https://discourse.julialang.org/u/Iulian.Cioarca)\
**Replies:** 2\
**Last updated:** [October 24, 2019, 10:04pm UTC](https://discourse.julialang.org/t/error-when-adding-packages-in-julia-1-3-rc04-on-windows/30276 "2019-10-24T22:04:52Z")

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I have been using Julia 1.3 rc04 happily for the past week. Today I hit \]update and got the error below. Now I can’t add any package at all… Resolving package versions... ┌ Warning: failed to extract archive downloaded …

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## [Separate compile cache for \`julia-debug\`?](https://discourse.julialang.org/t/separate-compile-cache-for-julia-debug/30032)

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**Author:** [@twadleigh](https://discourse.julialang.org/u/twadleigh)\
**Replies:** 7\
**Last updated:** [October 24, 2019, 9:39pm UTC](https://discourse.julialang.org/t/separate-compile-cache-for-julia-debug/30032 "2019-10-24T21:39:14Z")

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Whenever I run julia-debug for the first time in a while, I get: \[ Info: Precompiling Revise ...\] as it is initialized in my startup.jl. And, generally, the compile cache is invalidated and everything recompiled. When …

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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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## [ODE solver stats](https://discourse.julialang.org/t/ode-solver-stats/30150)

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**Author:** [@Nirvik](https://discourse.julialang.org/u/Nirvik)\
**Replies:** 11\
**Last updated:** [October 24, 2019, 7:29pm UTC](https://discourse.julialang.org/t/ode-solver-stats/30150 "2019-10-24T19:29:29Z")

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I would really appreciate if someone can briefly explain stats 3, 7-9. I did find any documentation on this: sol.destats DiffEqBase.DEStats Number of function 1 evaluations: 261 Number of function 2 eva…

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## [Bug? isapprox different results elementwise (Julia 1.1.0)](https://discourse.julialang.org/t/bug-isapprox-different-results-elementwise-julia-1-1-0/30271)

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**Author:** [@dcastel](https://discourse.julialang.org/u/dcastel)\
**Replies:** 3\
**Last updated:** [October 24, 2019, 4:06pm UTC](https://discourse.julialang.org/t/bug-isapprox-different-results-elementwise-julia-1-1-0/30271 "2019-10-24T16:06:07Z")

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I have this weird case where two tensors are element-wise and size-wise approx equal up to 3 digits but as a whole they aren’t. I’m still running Julia 1.1.0 though. alldigits = cat(\[\[0.375297 0.624703\]; \[0.39924 0.600…

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

<div class="topic-metadata">

**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)

<div class="topic-metadata">

**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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## [Memory Error](https://discourse.julialang.org/t/memory-error/30251)

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**Author:** [@natgeo-wong](https://discourse.julialang.org/u/natgeo-wong)\
**Replies:** 9\
**Last updated:** [October 24, 2019, 1:06pm UTC](https://discourse.julialang.org/t/memory-error/30251 "2019-10-24T13:06:16Z")

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Hi! I am currently using Julia to download, extract and resort data. The procedure is as follows: For each day a) Download data for every hour b) Extract hourly data and combine into a single matrix c) From that s…

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## [CSV.jl, Write to files](https://discourse.julialang.org/t/csv-jl-write-to-files/30265)

<div class="topic-metadata">

**Author:** [@Anil\_Mathews](https://discourse.julialang.org/u/Anil_Mathews)\
**Replies:** 3\
**Last updated:** [October 24, 2019, 11:58am UTC](https://discourse.julialang.org/t/csv-jl-write-to-files/30265 "2019-10-24T11:58:43Z")

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I was trying wite the companies name to CSV files. But I am getting the values what is the error in this code Letters=\["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y"…

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