# Latest

**URL:** https://discourse.julialang.org/latest.md?page=432

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

**Page:** 433

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## [Help me understand multi-threaded scaling for matrix multiplication](https://discourse.julialang.org/t/help-me-understand-multi-threaded-scaling-for-matrix-multiplication/112926)

<div class="topic-metadata">

**Author:** [@RayleighLord](https://discourse.julialang.org/u/RayleighLord)\
**Replies:** 22\
**Last updated:** [April 16, 2024, 6:29pm UTC](https://discourse.julialang.org/t/help-me-understand-multi-threaded-scaling-for-matrix-multiplication/112926 "2024-04-16T18:29:13Z")

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Hello, I would like to begin by clarifying that I have very little knowledge of multithreading. I was experimenting with the following code, using the MKL library to perform matrix multiplications with a different numbe…

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## [Creating an identifier column when combing multiple DataFrames with CSV.read](https://discourse.julialang.org/t/creating-an-identifier-column-when-combing-multiple-dataframes-with-csv-read/113013)

<div class="topic-metadata">

**Author:** [@phantom](https://discourse.julialang.org/u/phantom)\
**Replies:** 2\
**Last updated:** [April 16, 2024, 5:59pm UTC](https://discourse.julialang.org/t/creating-an-identifier-column-when-combing-multiple-dataframes-with-csv-read/113013 "2024-04-16T17:59:16Z")

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Suppose I have the following CSV files. df1 = DataFrame(A = 1:5, B = \["M", "F", "F", "M", "F"\]) df2 = DataFrame(A = 11:15, B = \["A", "B", "C", "D", "E"\]) df3 = DataFrame(A = 16:21, B = \["A", "B", "C", "D", "E","T"\]) …

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## [NonlinearSolve.jl - 'solve' not defined](https://discourse.julialang.org/t/nonlinearsolve-jl-solve-not-defined/113020)

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**Author:** [@Giovanni\_Bettolo](https://discourse.julialang.org/u/Giovanni_Bettolo)\
**Replies:** 5\
**Last updated:** [April 16, 2024, 5:34pm UTC](https://discourse.julialang.org/t/nonlinearsolve-jl-solve-not-defined/113020 "2024-04-16T17:34:33Z")

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I am new to Julia, I have been trying to test the NonlinearSolve.jl installation using the Problem Type 1 of “Getting Started with Nonlinear Rootfinding in Julia”, but it always returns the error ’LoadError: UndefVarErro…

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## [Ambiguity in change of variable behaviour in a struct?](https://discourse.julialang.org/t/ambiguity-in-change-of-variable-behaviour-in-a-struct/113012)

<div class="topic-metadata">

**Author:** [@Maddy](https://discourse.julialang.org/u/Maddy)\
**Replies:** 13\
**Last updated:** [April 16, 2024, 5:13pm UTC](https://discourse.julialang.org/t/ambiguity-in-change-of-variable-behaviour-in-a-struct/113012 "2024-04-16T17:13:52Z")

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I was recently writing some code and noticed a peculiar behaviour of structs Notice how earlier, I define a variable a with value 1. I push this into a list. Change the value of the list variable but that doesn’t cha…

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## [Addprocs: specify both multithreading and active environment](https://discourse.julialang.org/t/addprocs-specify-both-multithreading-and-active-environment/80427)

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**Author:** [@Gregstrq](https://discourse.julialang.org/u/Gregstrq)\
**Replies:** 2\
**Last updated:** [April 16, 2024, 5:11pm UTC](https://discourse.julialang.org/t/addprocs-specify-both-multithreading-and-active-environment/80427 "2024-04-16T17:11:02Z")

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Let’s say I want to add a process with 8 threads. This is easy: using Distributed addprocs(1, exeflags="-t 8") One can check that @fetchfrom 2 Threads.nthreads() returns 8 as expected. But, if I try to specify the env…

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## [Inserting Notebooks into LaTeX (LyX) documents?](https://discourse.julialang.org/t/inserting-notebooks-into-latex-lyx-documents/112972)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 4\
**Last updated:** [April 16, 2024, 4:28pm UTC](https://discourse.julialang.org/t/inserting-notebooks-into-latex-lyx-documents/112972 "2024-04-16T16:28:45Z")

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I’m trying to figure out how to insert Jupyter Notebooks into LaTeX documents. Specifically, I’m interested in how to do this with LyX. Although the latest version of LyX (2.4.0, in RC4 at the moment) supports Unicode ch…

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## [Inv not working in mac?](https://discourse.julialang.org/t/inv-not-working-in-mac/113014)

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**Author:** [@ivanricardo](https://discourse.julialang.org/u/ivanricardo)\
**Replies:** 9\
**Last updated:** [April 16, 2024, 4:21pm UTC](https://discourse.julialang.org/t/inv-not-working-in-mac/113014 "2024-04-16T16:21:46Z")

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Hello, So I have just installed julia 1.10.2 on a mac (M1) and I try running A = \[1 2 3;4 5 6;7 8 9\] inv(A) and I expect a singular error. However, I actually get a matrix as an output. What is weirder is that if I d…

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## [Vote for your favorite workshops at JuliaCon 2024!](https://discourse.julialang.org/t/vote-for-your-favorite-workshops-at-juliacon-2024/113026)

<div class="topic-metadata">

**Author:** [@ranjan](https://discourse.julialang.org/u/ranjan)\
**Replies:** 1\
**Last updated:** [April 16, 2024, 4:13pm UTC](https://discourse.julialang.org/t/vote-for-your-favorite-workshops-at-juliacon-2024/113026 "2024-04-16T16:13:27Z")

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Hi all, The list of JuliaCon 2024 Workshops has been released, and we now request everyone to vote for their favorite workshop! This poll is anonymous and we use these statistics for scheduling purposes. Best, Juli…

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## [GeometricMachineLearning.jl: Looking for a direct contact opportunity with persons involved](https://discourse.julialang.org/t/geometricmachinelearning-jl-looking-for-a-direct-contact-opportunity-with-persons-involved/113025)

<div class="topic-metadata">

**Author:** [@j\_u](https://discourse.julialang.org/u/j_u)\
**Replies:** 0\
**Last updated:** [April 16, 2024, 3:42pm UTC](https://discourse.julialang.org/t/geometricmachinelearning-jl-looking-for-a-direct-contact-opportunity-with-persons-involved/113025 "2024-04-16T15:42:48Z")

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Hi, I am looking for a direct contact opportunity with persons involved in GeometricMachineLearning.jl. I joined Julia Community a few years ago thanks to a hobby project of mine about "Neural network analysis of uncerta…

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## [How to specify xticks with min, max an arbitrary number?](https://discourse.julialang.org/t/how-to-specify-xticks-with-min-max-an-arbitrary-number/113021)

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**Author:** [@vladdez](https://discourse.julialang.org/u/vladdez)\
**Replies:** 0\
**Last updated:** [April 16, 2024, 3:03pm UTC](https://discourse.julialang.org/t/how-to-specify-xticks-with-min-max-an-arbitrary-number/113021 "2024-04-16T15:03:13Z")

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I want to specify ax.xticks with min of xvalue, 0.0, mean of xvalue, max of xvalue. How can I implement that?

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## [GPU memory usage increasing on each epoch (Flux)](https://discourse.julialang.org/t/gpu-memory-usage-increasing-on-each-epoch-flux/112942)

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**Author:** [@evanfields](https://discourse.julialang.org/u/evanfields)\
**Replies:** 5\
**Last updated:** [April 16, 2024, 2:16pm UTC](https://discourse.julialang.org/t/gpu-memory-usage-increasing-on-each-epoch-flux/112942 "2024-04-16T14:16:01Z")

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I’m catching up on the last few years of Flux progress (thanks, Flux devs!) by training some toy models, and am surprised to find that GPU memory usage is increasing on each training epoch, even when all training data is…

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## [Washington D.C. greater metro area meetups](https://discourse.julialang.org/t/washington-d-c-greater-metro-area-meetups/26862)

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**Author:** [@Nosferican](https://discourse.julialang.org/u/Nosferican)\
**Replies:** 7\
**Last updated:** [April 16, 2024, 1:46pm UTC](https://discourse.julialang.org/t/washington-d-c-greater-metro-area-meetups/26862 "2024-04-16T13:46:31Z")

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This is for connecting the Julia community in the Washington D.C. greater metro area. This is me, Name: José Bayoán Santiago Calderón GitHub: Nosferican Slack: Nosferican I live in Pentagon City (Arlington, VA) and …

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## [Cubature of Singular Integrand](https://discourse.julialang.org/t/cubature-of-singular-integrand/113003)

<div class="topic-metadata">

**Author:** [@Domenico\_Lahaye](https://discourse.julialang.org/u/Domenico_Lahaye)\
**Replies:** 3\
**Last updated:** [April 16, 2024, 1:33pm UTC](https://discourse.julialang.org/t/cubature-of-singular-integrand/113003 "2024-04-16T13:33:06Z")

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?quadgk provides as output !!! note Only one-dimensional integrals are provided by this function. For multi-dimensional integration (cubature), there are many different algorithms (often much better than simple nested 1…

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## [Are there any tools in julia that can test the peak memory consumption of the functions I wrote?](https://discourse.julialang.org/t/are-there-any-tools-in-julia-that-can-test-the-peak-memory-consumption-of-the-functions-i-wrote/113011)

<div class="topic-metadata">

**Author:** [@F-YF](https://discourse.julialang.org/u/F-YF)\
**Replies:** 1\
**Last updated:** [April 16, 2024, 1:00pm UTC](https://discourse.julialang.org/t/are-there-any-tools-in-julia-that-can-test-the-peak-memory-consumption-of-the-functions-i-wrote/113011 "2024-04-16T13:00:03Z")

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Let’s look at this example first: julia\> using BenchmarkTools julia\> julia\> function f(x::Matrix{Float64}) y = x \* x return nothing end f (generic function with 1 method) julia\> julia\> …

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## [Question regarding numerical stability among Julia versions](https://discourse.julialang.org/t/question-regarding-numerical-stability-among-julia-versions/112741)

<div class="topic-metadata">

**Author:** [@CodeLenz](https://discourse.julialang.org/u/CodeLenz)\
**Replies:** 16\
**Last updated:** [April 16, 2024, 12:54pm UTC](https://discourse.julialang.org/t/question-regarding-numerical-stability-among-julia-versions/112741 "2024-04-16T12:54:05Z")

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Dear Julians. I was testing the following code (M,C and K are sparse, symmetric and positive definite matrices) Julia\> M,C,K=THS(); julia\> cholM=cholesky(M); julia\> Cb = cholM\\C; julia\> Kb = cholM\\K; julia\> F = 0.…

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## [Solving a nonlinear equation using NonlinearSolve.jl with AutoFiniteDiff() yields errors about dual number](https://discourse.julialang.org/t/solving-a-nonlinear-equation-using-nonlinearsolve-jl-with-autofinitediff-yields-errors-about-dual-number/112988)

<div class="topic-metadata">

**Author:** [@LINGXIAO\_QIN](https://discourse.julialang.org/u/LINGXIAO_QIN)\
**Replies:** 2\
**Last updated:** [April 16, 2024, 12:13pm UTC](https://discourse.julialang.org/t/solving-a-nonlinear-equation-using-nonlinearsolve-jl-with-autofinitediff-yields-errors-about-dual-number/112988 "2024-04-16T12:13:18Z")

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I am trying to solve a nonlinear equation, which is constructed using the thermophysical properties of fluids (via CoolProp package). An MWE is shown below. using NonlinearSolve, CoolProp function myfun\_P\_MWE(p, (T, i…

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## [Speed up JuMP.jl Estimation When Jacobian and Hessian of Constraints are Sparse](https://discourse.julialang.org/t/speed-up-jump-jl-estimation-when-jacobian-and-hessian-of-constraints-are-sparse/112981)

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**Author:** [@Strange\_Xue](https://discourse.julialang.org/u/Strange_Xue)\
**Replies:** 6\
**Last updated:** [April 16, 2024, 11:08am UTC](https://discourse.julialang.org/t/speed-up-jump-jl-estimation-when-jacobian-and-hessian-of-constraints-are-sparse/112981 "2024-04-16T11:08:20Z")

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Hi guys, in last questions (link is shown below), I asked how to supply gradient of objective and jacobian of constraints in nonlinear optimization. But @odow told me I dont have to do that because JuMP.jl will automatic…

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## [NeuralODE with covariates](https://discourse.julialang.org/t/neuralode-with-covariates/112999)

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**Author:** [@elcup](https://discourse.julialang.org/u/elcup)\
**Replies:** 1\
**Last updated:** [April 16, 2024, 9:34am UTC](https://discourse.julialang.org/t/neuralode-with-covariates/112999 "2024-04-16T09:34:16Z")

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Hi. Am an quite new with Julia and I am stuck with something. Maybe you can help me (sorry if I am trying something stupid). I am working with Neural ODEs using DiffEqFlux. I want to model the differential equation with…

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## [Changelog.jl release announcement](https://discourse.julialang.org/t/changelog-jl-release-announcement/112996)

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**Author:** [@fredrikekre](https://discourse.julialang.org/u/fredrikekre)\
**Replies:** 0\
**Last updated:** [April 16, 2024, 8:04am UTC](https://discourse.julialang.org/t/changelog-jl-release-announcement/112996 "2024-04-16T08:04:55Z")

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I want to announce Changelog.jl – a small utility package that helps with changelog maintenance. It was released in the registry back in November last year but was never announced here. The two main functionalities are…

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## [Optimising iterative solution of small system](https://discourse.julialang.org/t/optimising-iterative-solution-of-small-system/112885)

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**Author:** [@alemelis](https://discourse.julialang.org/u/alemelis)\
**Replies:** 12\
**Last updated:** [April 16, 2024, 7:46am UTC](https://discourse.julialang.org/t/optimising-iterative-solution-of-small-system/112885 "2024-04-16T07:46:29Z")

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Hello again, I’m solving iteratively this system of 6 equations as part of a larger simulation Toy datausing StaticArrays using LinearAlgebra mutable struct V{T} u::T A::T A0::T γ::T β::T end st…

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## [How to print similar tabular process output?](https://discourse.julialang.org/t/how-to-print-similar-tabular-process-output/112928)

<div class="topic-metadata">

**Author:** [@WuSiren](https://discourse.julialang.org/u/WuSiren)\
**Replies:** 6\
**Last updated:** [April 16, 2024, 7:33am UTC](https://discourse.julialang.org/t/how-to-print-similar-tabular-process-output/112928 "2024-04-16T07:33:03Z")

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How can I print a similar tabular process output in my code? (make them aligned) Nodes | B&B Tree | Objective Bounds | Dynamic Constraints | Work Proc. InQue…

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## [Auto indent after inputing pipe and a return](https://discourse.julialang.org/t/auto-indent-after-inputing-pipe-and-a-return/112994)

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**Author:** [@cocoa1231](https://discourse.julialang.org/u/cocoa1231)\
**Replies:** 0\
**Last updated:** [April 16, 2024, 7:26am UTC](https://discourse.julialang.org/t/auto-indent-after-inputing-pipe-and-a-return/112994 "2024-04-16T07:26:58Z")

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I often end up chaining pipes as follows and in jupyter notebook at least, I have to input a tab after every pipe. Would it be possible somehow to tell the language server to indent after I input a pipe and return? proc…

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## [Segfault when using PythonCall.jl with Plots.jl](https://discourse.julialang.org/t/segfault-when-using-pythoncall-jl-with-plots-jl/112944)

<div class="topic-metadata">

**Author:** [@sadish-d](https://discourse.julialang.org/u/sadish-d)\
**Replies:** 1\
**Last updated:** [April 16, 2024, 2:42am UTC](https://discourse.julialang.org/t/segfault-when-using-pythoncall-jl-with-plots-jl/112944 "2024-04-16T02:42:47Z")

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I have a package that uses PythonCall.jl to import and use the python library TTS. Importing Plots.jl seems to be causing a segmentation fault. Below is a minimum working example. If I import Pytest and then call f(), it…

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## [An off-topic question: Why is it \`add\`/\`import\` a package, but \`using\` instead of \`use\` it?](https://discourse.julialang.org/t/an-off-topic-question-why-is-it-add-import-a-package-but-using-instead-of-use-it/112948)

<div class="topic-metadata">

**Author:** [@WuSiren](https://discourse.julialang.org/u/WuSiren)\
**Replies:** 3\
**Last updated:** [April 16, 2024, 1:28am UTC](https://discourse.julialang.org/t/an-off-topic-question-why-is-it-add-import-a-package-but-using-instead-of-use-it/112948 "2024-04-16T01:28:45Z")

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An off-topic question: Why is it add/import a package, but using instead of use it?

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## [Will return allocate memory?](https://discourse.julialang.org/t/will-return-allocate-memory/112987)

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**Author:** [@Strange\_Xue](https://discourse.julialang.org/u/Strange_Xue)\
**Replies:** 3\
**Last updated:** [April 16, 2024, 1:19am UTC](https://discourse.julialang.org/t/will-return-allocate-memory/112987 "2024-04-16T01:19:00Z")

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Hi guys, looking at the following two versions of codes. I found more allocations in version 2 perhaps because b is returned in version 2. However, b = \[a\] is also operated in both versions. Why is there a big difference…

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## [Is Julia slow at closing files on Windows?](https://discourse.julialang.org/t/is-julia-slow-at-closing-files-on-windows/112983)

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**Author:** [@Ahmed\_Salih](https://discourse.julialang.org/u/Ahmed_Salih)\
**Replies:** 1\
**Last updated:** [April 16, 2024, 12:38am UTC](https://discourse.julialang.org/t/is-julia-slow-at-closing-files-on-windows/112983 "2024-04-16T00:38:21Z")

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Hello! It is hard to provide a MWE, since this is a pattern I observe when running a simulation in Julia. I time the different operation and I see that closing a file through HDF5.jl takes up more time than I think it s…

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## [\`in(x, y)\` and \`y in x\` behave differently?](https://discourse.julialang.org/t/in-x-y-and-y-in-x-behave-differently/112965)

<div class="topic-metadata">

**Author:** [@filchristou](https://discourse.julialang.org/u/filchristou)\
**Replies:** 8\
**Last updated:** [April 15, 2024, 11:53pm UTC](https://discourse.julialang.org/t/in-x-y-and-y-in-x-behave-differently/112965 "2024-04-15T23:53:39Z")

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I made a dummy range struct MyRange starting::Int ending::Int end for which I only care to check whether integers are contained there. Consequently I implemented the Base.in function Base.in(r::MyRange, i::In…

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## [Error when using MKLDirectSolver in SCS](https://discourse.julialang.org/t/error-when-using-mkldirectsolver-in-scs/112982)

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**Author:** [@charshaw](https://discourse.julialang.org/u/charshaw)\
**Replies:** 2\
**Last updated:** [April 15, 2024, 11:20pm UTC](https://discourse.julialang.org/t/error-when-using-mkldirectsolver-in-scs/112982 "2024-04-15T23:20:59Z")

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I am using JuMP and calling SCS as a solver. I want to use SCS.MKLDirectSolver, as discussed in an earlier thread. As discussed on the SCS.jl README page, this requires using the package SCS\_MKL\_jll. But, I’m getting an…

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## [Clarification on when order matters when reading multiple files with CSV.read?](https://discourse.julialang.org/t/clarification-on-when-order-matters-when-reading-multiple-files-with-csv-read/112970)

<div class="topic-metadata">

**Author:** [@phantom](https://discourse.julialang.org/u/phantom)\
**Replies:** 4\
**Last updated:** [April 15, 2024, 11:03pm UTC](https://discourse.julialang.org/t/clarification-on-when-order-matters-when-reading-multiple-files-with-csv-read/112970 "2024-04-15T23:03:17Z")

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When using CSV.read to read multiple CSV files into a single DataFrame. When does the order the files are listed makes a difference. @nilshg points out that this is an issue with pooled arrays and can be remedied by s…

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## [How to get help on a Julia command on a Jupyter notebook?](https://discourse.julialang.org/t/how-to-get-help-on-a-julia-command-on-a-jupyter-notebook/112976)

<div class="topic-metadata">

**Author:** [@younes](https://discourse.julialang.org/u/younes)\
**Replies:** 7\
**Last updated:** [April 15, 2024, 9:56pm UTC](https://discourse.julialang.org/t/how-to-get-help-on-a-julia-command-on-a-jupyter-notebook/112976 "2024-04-15T21:56:47Z")

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I already tried : ?replace ParseError: # Error @ /home/onto/dev/projects/intro\_julia.ipynb:1:1 ?replace ╙ ── not a unary operator Stacktrace: \[1\] top-level scope @ ~/dev/projects/intro\_julia.ipynb:1 but it does w…

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