# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1108

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

**Page:** 1109

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## [If statement executing when comparing equality of hyphen](https://discourse.julialang.org/t/if-statement-executing-when-comparing-equality-of-hyphen/77230)

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**Author:** [@imantha](https://discourse.julialang.org/u/imantha)\
**Replies:** 2\
**Last updated:** [March 1, 2022, 12:57pm UTC](https://discourse.julialang.org/t/if-statement-executing-when-comparing-equality-of-hyphen/77230 "2022-03-01T12:57:18Z")

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Hi I am wondering what I am doing incorrectly here, somestring = "2021\_10\_20-sess05-spk\_M\_C\_010.pdf" if somestring\[11\] != "-" @show somestring\[11\],"incorrect" end \>\>\> ("-", incorrect) It shouldnt be executing sin…

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## [How to extend SecondOrderODEProblem in DifferentialEquations.jl?](https://discourse.julialang.org/t/how-to-extend-secondorderodeproblem-in-differentialequations-jl/73831)

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**Author:** [@ziolai](https://discourse.julialang.org/u/ziolai)\
**Replies:** 14\
**Last updated:** [March 1, 2022, 12:55pm UTC](https://discourse.julialang.org/t/how-to-extend-secondorderodeproblem-in-differentialequations-jl/73831 "2022-03-01T12:55:52Z")

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Greetings. SecondOrderODEProblem in DifferentialEquations solves u\_{tt} = f(u\_t,u,p,t), see Dynamical, Hamiltonian and 2nd Order ODE Problems · DifferentialEquations.jl . Please suggest how to extend this to include (u…

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## [How best to use a custom module?](https://discourse.julialang.org/t/how-best-to-use-a-custom-module/77066)

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**Author:** [@LeoK987](https://discourse.julialang.org/u/LeoK987)\
**Replies:** 18\
**Last updated:** [March 1, 2022, 10:34am UTC](https://discourse.julialang.org/t/how-best-to-use-a-custom-module/77066 "2022-03-01T10:34:25Z")

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Hi guys, I have been away from Julia since end of 2018. Now coming back and looking at my old code now with Julia 1.7, I feel puzzled at how best to use my own modules. My modules are in subdirectories under the root …

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## [Having problem with Convex.jl](https://discourse.julialang.org/t/having-problem-with-convex-jl/77196)

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**Author:** [@janilin](https://discourse.julialang.org/u/janilin)\
**Replies:** 4\
**Last updated:** [March 1, 2022, 6:08am UTC](https://discourse.julialang.org/t/having-problem-with-convex-jl/77196 "2022-03-01T06:08:49Z")

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Hi! I’m new to Julia. While I was going through the Julia for Data Science course’s \*\* Numerical Optimization\*\* lecture, got stucked in solve!() unfortunately. Explored in different forums but could not get the solution…

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## [Can Metatheory.jl work functional equal to Prolog?](https://discourse.julialang.org/t/can-metatheory-jl-work-functional-equal-to-prolog/77185)

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**Author:** [@Junars](https://discourse.julialang.org/u/Junars)\
**Replies:** 7\
**Last updated:** [March 1, 2022, 2:28am UTC](https://discourse.julialang.org/t/can-metatheory-jl-work-functional-equal-to-prolog/77185 "2022-03-01T02:28:25Z")

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I’m rewriting a Reasoning System using Julia. The system has many rules written in Prolog, I want to use these existing prolog rules, because they are declarative and could make the whole system easy to debug it’s contro…

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## [How to find the data in the nearest grid point?](https://discourse.julialang.org/t/how-to-find-the-data-in-the-nearest-grid-point/77213)

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**Author:** [@leon](https://discourse.julialang.org/u/leon)\
**Replies:** 1\
**Last updated:** [March 1, 2022, 2:12am UTC](https://discourse.julialang.org/t/how-to-find-the-data-in-the-nearest-grid-point/77213 "2022-03-01T02:12:16Z")

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I have some ship track based data missing one of the variables (Var1) that I want to extract from a gridded database (1 x 1 degree). At one location of my ship track, there will be 4 grid points (Left up, left down, rig…

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## [Comparing RNNs versus Neural ODEs for time series prediction](https://discourse.julialang.org/t/comparing-rnns-versus-neural-odes-for-time-series-prediction/77206)

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**Author:** [@00krishna](https://discourse.julialang.org/u/00krishna)\
**Replies:** 2\
**Last updated:** [March 1, 2022, 12:33am UTC](https://discourse.julialang.org/t/comparing-rnns-versus-neural-odes-for-time-series-prediction/77206 "2022-03-01T00:33:47Z")

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Hey folks. Say, I was playing around with some simple NeuralODEs (NODEs) in DiffEqFlux, and have worked with RNNs in the past. I was trying to understand the difference in prediction accuracy between RNNs and NeuralODE…

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## [VS Code: No implementation found in developed package](https://discourse.julialang.org/t/vs-code-no-implementation-found-in-developed-package/77198)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 6\
**Last updated:** [February 28, 2022, 10:29pm UTC](https://discourse.julialang.org/t/vs-code-no-implementation-found-in-developed-package/77198 "2022-02-28T22:29:00Z")

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I work with code which references functions defined in a package developed side-by-side with the current environment/file. The implementation of the function view\_modes is reported as not found, however. This function …

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## [Add repo outside of github as dependency to local package](https://discourse.julialang.org/t/add-repo-outside-of-github-as-dependency-to-local-package/77209)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 7\
**Last updated:** [February 28, 2022, 10:16pm UTC](https://discourse.julialang.org/t/add-repo-outside-of-github-as-dependency-to-local-package/77209 "2022-02-28T22:16:35Z")

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Hi all, I have a project that is set up as a local package using PkgTemplates. I would like to add a private Julia package that is hosted on a git repo outside of Github. I am having trouble getting it to work. I added…

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## [General Arrow questions](https://discourse.julialang.org/t/general-arrow-questions/77191)

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**Author:** [@tbeason](https://discourse.julialang.org/u/tbeason)\
**Replies:** 7\
**Last updated:** [February 28, 2022, 10:00pm UTC](https://discourse.julialang.org/t/general-arrow-questions/77191 "2022-02-28T22:00:31Z")

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I am considering switching to Arrow to improve my data loading times. Here is my setup: just over 1,000 files, each representing a single date, currently stored in SAS .sas7bdat format, sizes ranging from a 100MB to 3GB.…

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## [Run Julia server as Windows Service to work after user log out](https://discourse.julialang.org/t/run-julia-server-as-windows-service-to-work-after-user-log-out/37261)

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**Author:** [@sairus7](https://discourse.julialang.org/u/sairus7)\
**Replies:** 2\
**Last updated:** [February 28, 2022, 9:54pm UTC](https://discourse.julialang.org/t/run-julia-server-as-windows-service-to-work-after-user-log-out/37261 "2022-02-28T21:54:16Z")

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I’m trying to make Julia server working on a Windows machine without being closed when a user log out. So, I’ve tried to wrap a simple Julia HTTP server script (and WebSocket server script) into a service on Windows 10 …

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## [Iterator tool similar to zip (mesh?)](https://discourse.julialang.org/t/iterator-tool-similar-to-zip-mesh/77137)

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**Author:** [@reinermartin](https://discourse.julialang.org/u/reinermartin)\
**Replies:** 23\
**Last updated:** [February 28, 2022, 9:35pm UTC](https://discourse.julialang.org/t/iterator-tool-similar-to-zip-mesh/77137 "2022-02-28T21:35:50Z")

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Sometimes I would find it useful to ‘zip’ or ‘mesh’ two or more iterators in a way that each iterator runs in turn, and once one is exhausted it continues to use the remaining ones. For example, when I want to search thr…

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## [How to pass set of attributes to command](https://discourse.julialang.org/t/how-to-pass-set-of-attributes-to-command/77161)

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**Author:** [@talby](https://discourse.julialang.org/u/talby)\
**Replies:** 8\
**Last updated:** [February 28, 2022, 8:17pm UTC](https://discourse.julialang.org/t/how-to-pass-set-of-attributes-to-command/77161 "2022-02-28T20:17:23Z")

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how to pass set of attributes to command How to pass a set of attributes to a command by having all attributes predefined in an array (?), string (?), whatever (?) ? A general solution is preferred to learn about, but …

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## [Sqlite database remains in use by Julia REPL](https://discourse.julialang.org/t/sqlite-database-remains-in-use-by-julia-repl/77194)

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**Author:** [@Marie](https://discourse.julialang.org/u/Marie)\
**Replies:** 5\
**Last updated:** [February 28, 2022, 4:29pm UTC](https://discourse.julialang.org/t/sqlite-database-remains-in-use-by-julia-repl/77194 "2022-02-28T16:29:08Z")

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I have a small program that creates sqlite database with a single table. Inserts some data into the table. In the end of program execution database file remains in use by Julia. I have to kill REPL terminal to release i…

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## [Get tuple length from type?](https://discourse.julialang.org/t/get-tuple-length-from-type/32483)

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**Author:** [@ssfrr](https://discourse.julialang.org/u/ssfrr)\
**Replies:** 19\
**Last updated:** [February 28, 2022, 5:12pm UTC](https://discourse.julialang.org/t/get-tuple-length-from-type/32483 "2022-02-28T17:12:57Z")

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Is there a built-in function to get the length of a tuple as a Val{N}? Basically I’m looking for something that would be of the form: tuplen(::Type{Tuple{}}) = Val{0}() tuplen(::Type{Tuple{T}}) where T = Val{1}() tuple…

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## [Juliaup and beta release](https://discourse.julialang.org/t/juliaup-and-beta-release/77195)

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**Author:** [@dmbates](https://discourse.julialang.org/u/dmbates)\
**Replies:** 1\
**Last updated:** [February 28, 2022, 3:25pm UTC](https://discourse.julialang.org/t/juliaup-and-beta-release/77195 "2022-02-28T15:25:52Z")

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Alex has announced Julia v1.8.0-beta1 is now on the download sites. I was hoping that juliaup add beta would download and install this version but it doesn’t seem to do so. Am I misunderstanding how the beta channel …

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## [Hash(1) change between 1.5 and 1.6](https://discourse.julialang.org/t/hash-1-change-between-1-5-and-1-6/77101)

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**Author:** [@Jon\_Barker](https://discourse.julialang.org/u/Jon_Barker)\
**Replies:** 7\
**Last updated:** [February 28, 2022, 3:08pm UTC](https://discourse.julialang.org/t/hash-1-change-between-1-5-and-1-6/77101 "2022-02-28T15:08:48Z")

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Hi all, I’m trying to recreate the Hash(1) value from Julia 1.1 in our Julia 1.6 codebase. Hash(1) Julia 1.5: 0x02011ce34bce797f Hash(1) Julia 1.6: 0x5bca7c69b794f8ce I’ve delved deep into the c code, without a lot of…

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## [Create parametric structure with metaprogramming](https://discourse.julialang.org/t/create-parametric-structure-with-metaprogramming/77184)

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**Author:** [@Albert\_de\_montserrat](https://discourse.julialang.org/u/Albert_de_montserrat)\
**Replies:** 5\
**Last updated:** [February 28, 2022, 3:02pm UTC](https://discourse.julialang.org/t/create-parametric-structure-with-metaprogramming/77184 "2022-02-28T15:02:24Z")

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I’m trying to use metraprogramming to create structures on the fly. I managed to make a construtor for a vanilla struct as: function makestruct(name::Symbol, ndim::Integer) dims = (:x, :y, :z) fields = \[:( $(dim…

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## [Problem using Julia in VS Code](https://discourse.julialang.org/t/problem-using-julia-in-vs-code/77160)

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**Author:** [@pafloxy](https://discourse.julialang.org/u/pafloxy)\
**Replies:** 5\
**Last updated:** [February 28, 2022, 2:57pm UTC](https://discourse.julialang.org/t/problem-using-julia-in-vs-code/77160 "2022-02-28T14:57:54Z")

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I have recently installed VS code in my system, and added julia as an extension in it. However I have not been able to run julia scripts in it ! I was trying to run a simple helloworld script but it ended up with this m…

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## [Timestamps in \[MsgPack.jl\](https://github.com/JuliaIO/MsgPack.jl)](https://discourse.julialang.org/t/timestamps-in-msgpack-jl-https-github-com-juliaio-msgpack-jl/40255)

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**Author:** [@Impressium](https://discourse.julialang.org/u/Impressium)\
**Replies:** 1\
**Last updated:** [May 29, 2020, 12:22am UTC](https://discourse.julialang.org/t/timestamps-in-msgpack-jl-https-github-com-juliaio-msgpack-jl/40255 "2020-05-29T00:22:34Z")

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Hey :slight\_smile: I’m using MsgPack.jl and trying to add an ExtentionType (Link). But I want to define my one deserialization as defined here. I hope someone knows how it works :+1:

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## [MsgPack.ExtensionType for Date](https://discourse.julialang.org/t/msgpack-extensiontype-for-date/77188)

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**Author:** [@nsslh](https://discourse.julialang.org/u/nsslh)\
**Replies:** 0\
**Last updated:** [February 28, 2022, 2:18pm UTC](https://discourse.julialang.org/t/msgpack-extensiontype-for-date/77188 "2022-02-28T14:18:52Z")

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I am trying to write the Julia end of an RPC-over-RabbitMQ relationship. The other side (written in Ruby) uses a MsgPack extension for dates. I receive this: MsgPack.Extension(1, UInt8\[0x07, 0xe6, 0x02, 0x1c\]) I can ma…

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## [Inaccurate Matrix Multiplication](https://discourse.julialang.org/t/inaccurate-matrix-multiplication/76903)

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**Author:** [@judober](https://discourse.julialang.org/u/judober)\
**Replies:** 39\
**Last updated:** [February 28, 2022, 2:02pm UTC](https://discourse.julialang.org/t/inaccurate-matrix-multiplication/76903 "2022-02-28T14:02:12Z")

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We experienced an issue with Matrix-Vector (or row-vector times column-vector) product. In the example the result should return zero: a = \[1.3190624946305824, 1.3190624946305824\] b = \[-3.74 3.74\] # Matrix-Vector-Produ…

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## [Have I bought a fake i9-11900K?](https://discourse.julialang.org/t/have-i-bought-a-fake-i9-11900k/77109)

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**Author:** [@photor](https://discourse.julialang.org/u/photor)\
**Replies:** 28\
**Last updated:** [February 28, 2022, 1:59pm UTC](https://discourse.julialang.org/t/have-i-bought-a-fake-i9-11900k/77109 "2022-02-28T13:59:58Z")

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Intel i9-11900K is supposed to be the top one in the 11th Gen CPU family. Recently I bought a desktop computer with this CPU, but its performance is not satisfactory. Shortly after that, I bought a laptop with an i7-1180…

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## [Creating a loss function for sciml\_train with unequal time point distribution of the ODE components](https://discourse.julialang.org/t/creating-a-loss-function-for-sciml-train-with-unequal-time-point-distribution-of-the-ode-components/75204)

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**Author:** [@Marius\_123](https://discourse.julialang.org/u/Marius_123)\
**Replies:** 13\
**Last updated:** [February 28, 2022, 1:52pm UTC](https://discourse.julialang.org/t/creating-a-loss-function-for-sciml-train-with-unequal-time-point-distribution-of-the-ode-components/75204 "2022-02-28T13:52:27Z")

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Hello, i am wondering how i can build an apropriate loss function for parameter estimation with DiffEqFlux.sciml\_train if i have data points from the ODE at different time points in each component. Can maybe someone hel…

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## [Interpreted and compiled hybrid](https://discourse.julialang.org/t/interpreted-and-compiled-hybrid/77170)

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**Author:** [@dklonaros](https://discourse.julialang.org/u/dklonaros)\
**Replies:** 4\
**Last updated:** [February 28, 2022, 12:53pm UTC](https://discourse.julialang.org/t/interpreted-and-compiled-hybrid/77170 "2022-02-28T12:53:15Z")

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I love Julia’s efficiency and the speed with which I can complete certain tasks once it is compiled. The only slight gripe I have as a data scientist, especially when exploring large datasets, is the time needed in the b…

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## [Correct way to prepare dependencies of a julia project for publishing?](https://discourse.julialang.org/t/correct-way-to-prepare-dependencies-of-a-julia-project-for-publishing/77176)

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**Author:** [@Kevin\_Shen1](https://discourse.julialang.org/u/Kevin_Shen1)\
**Replies:** 9\
**Last updated:** [February 28, 2022, 12:52pm UTC](https://discourse.julialang.org/t/correct-way-to-prepare-dependencies-of-a-julia-project-for-publishing/77176 "2022-02-28T12:52:26Z")

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I come from python where each environment has an independent list of packages. This simplifies publishing the project to github because you can just install from a requirements.txt file. According to this Q&A Understand…

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## [Discard elements of function output?](https://discourse.julialang.org/t/discard-elements-of-function-output/77179)

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**Author:** [@fredrikpaues](https://discourse.julialang.org/u/fredrikpaues)\
**Replies:** 2\
**Last updated:** [February 28, 2022, 12:11pm UTC](https://discourse.julialang.org/t/discard-elements-of-function-output/77179 "2022-02-28T12:11:09Z")

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In MATLAB, I would write \[~, two\] = function\_with\_two\_outputs() to discard the first of two function outputs. Is there a syntax for doing the same in Julia? That is, discard one or more elements of the tuple returned by …

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## [Plots -- new syntax for marker stroke color?](https://discourse.julialang.org/t/plots-new-syntax-for-marker-stroke-color/70552)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 2\
**Last updated:** [February 28, 2022, 10:44am UTC](https://discourse.julialang.org/t/plots-new-syntax-for-marker-stroke-color/70552 "2022-02-28T10:44:46Z")

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I want to set the markerstrokecolor equal to the markercolor to make the label nice scatter!(.., mc=colTs,msc=colTs,...) – I’ve done so in this figure: If I don’t specify the markerstrokecolor and set it equal to t…

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## [Transform operation using two or more columns in a DataFrame](https://discourse.julialang.org/t/transform-operation-using-two-or-more-columns-in-a-dataframe/77172)

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**Author:** [@imantha](https://discourse.julialang.org/u/imantha)\
**Replies:** 6\
**Last updated:** [February 28, 2022, 9:45am UTC](https://discourse.julialang.org/t/transform-operation-using-two-or-more-columns-in-a-dataframe/77172 "2022-02-28T09:45:19Z")

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Hi I am wondering how to use transform!() or transform!() + ByRow() functions to do computations utilizing two or more columns Essentially I want to perform the the function below however using transform!() data = Dict…

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## [Defining an array of MTK variables causes error with ModelingToolkit.discretize()](https://discourse.julialang.org/t/defining-an-array-of-mtk-variables-causes-error-with-modelingtoolkit-discretize/77153)

<div class="topic-metadata">

**Author:** [@Fathya.Salih](https://discourse.julialang.org/u/Fathya.Salih)\
**Replies:** 4\
**Last updated:** [February 28, 2022, 8:05am UTC](https://discourse.julialang.org/t/defining-an-array-of-mtk-variables-causes-error-with-modelingtoolkit-discretize/77153 "2022-02-28T08:05:04Z")

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I am trying to solve a number of ODEs for a set of variables (u\_1, u\_2, ..., u\_6) using MethodOfLines.jl, but I get this error MethodError: no method matching nameof(::SymbolicUtils.Term{SymbolicUtils.FnType{Tuple, Real…

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