# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1813

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

**Page:** 1814

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## [Handy function for making empty arrays](https://discourse.julialang.org/t/handy-function-for-making-empty-arrays/35241)

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**Author:** [@Tbl](https://discourse.julialang.org/u/Tbl)\
**Replies:** 5\
**Last updated:** [February 29, 2020, 3:19pm UTC](https://discourse.julialang.org/t/handy-function-for-making-empty-arrays/35241 "2020-02-29T15:19:24Z")

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I am teaching Julia to students with Python background and one thing cough my attention: there are few useful functions for making basic matrices, like zeros, ones, trues, falses, fill, similar, but there is no such func…

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## [Same key for run-file and continue](https://discourse.julialang.org/t/same-key-for-run-file-and-continue/35306)

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**Author:** [@luc-j-bourhis](https://discourse.julialang.org/u/luc-j-bourhis)\
**Replies:** 1\
**Last updated:** [February 29, 2020, 10:13am UTC](https://discourse.julialang.org/t/same-key-for-run-file-and-continue/35306 "2020-02-29T10:13:55Z")

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Coming from a different IDE (for Python), I got used to having the same key to initiate debugging, “run-file” assigned to F5 by default, and “continue” assigned to F8 by default. So basically, F5 starts debugging if it i…

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## [Submatrix multiply](https://discourse.julialang.org/t/submatrix-multiply/35309)

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**Author:** [@hytonwons](https://discourse.julialang.org/u/hytonwons)\
**Replies:** 7\
**Last updated:** [February 29, 2020, 7:14am UTC](https://discourse.julialang.org/t/submatrix-multiply/35309 "2020-02-29T07:14:48Z")

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Hi, my algorithm involves a lot of submatrix multiply. I got inspired by the use of view, but the speedup of doing so is not that satisfying. Below is some sample code: If we just try slicing the matrix, the speedup is …

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## [A couple questions on profiling](https://discourse.julialang.org/t/a-couple-questions-on-profiling/35290)

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**Author:** [@riccardomurri](https://discourse.julialang.org/u/riccardomurri)\
**Replies:** 3\
**Last updated:** [February 29, 2020, 7:01am UTC](https://discourse.julialang.org/t/a-couple-questions-on-profiling/35290 "2020-02-29T07:01:53Z")

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I am trying to profile a piece of code that runs for about 15 minutes. If I use the default settings in Profile.init(), the profile buffer fills up when Julia is still compiling my code, so I don’t get any useful inform…

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## [Unit conversion](https://discourse.julialang.org/t/unit-conversion/35302)

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**Author:** [@erlebach](https://discourse.julialang.org/u/erlebach)\
**Replies:** 12\
**Last updated:** [February 29, 2020, 6:30am UTC](https://discourse.julialang.org/t/unit-conversion/35302 "2020-02-29T06:30:41Z")

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Hi, I am new to Julia and am trying out Unitful. I would like to do the following: a = 1"m" / 1"cm" and have it return 100. What must I do to make this happen? It is clearly not automatic. Similarly, I would like: …

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## [Is there a way to suppress "method overwritten" warnings?](https://discourse.julialang.org/t/is-there-a-way-to-suppress-method-overwritten-warnings/3233)

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**Author:** [@DIzer](https://discourse.julialang.org/u/DIzer)\
**Replies:** 24\
**Last updated:** [February 29, 2020, 6:19am UTC](https://discourse.julialang.org/t/is-there-a-way-to-suppress-method-overwritten-warnings/3233 "2020-02-29T06:19:03Z")

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more over i am still not sure whether it is bug or ugly implemented feature…

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## [How to print arrays inside functions?](https://discourse.julialang.org/t/how-to-print-arrays-inside-functions/4091)

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**Author:** [@matthieu](https://discourse.julialang.org/u/matthieu)\
**Replies:** 12\
**Last updated:** [February 29, 2020, 6:05am UTC](https://discourse.julialang.org/t/how-to-print-arrays-inside-functions/4091 "2020-02-29T06:05:34Z")

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It is useful to peak at an array when debugging a function. However, the macro @show prints arrays like vectors. How to print arrays in the correct REPL way? zeros(5, 5) #\>5×5 Array{Float64,2}: #\> 0.0 0.0 0.0 0.0 0.…

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## [Code to train a Support Vector Machine?](https://discourse.julialang.org/t/code-to-train-a-support-vector-machine/35300)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 0\
**Last updated:** [February 28, 2020, 8:39pm UTC](https://discourse.julialang.org/t/code-to-train-a-support-vector-machine/35300 "2020-02-28T20:39:15Z")

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Hello, In the MITx 6.86x “Machine Learning with Python-From Linear Models to Deep Learning” course we has been presented with a recitation that uses scikit-learn to train a SVM model (code follows). In particular, the …

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## [Export metagraph with node properties](https://discourse.julialang.org/t/export-metagraph-with-node-properties/35295)

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**Author:** [@feanor12](https://discourse.julialang.org/u/feanor12)\
**Replies:** 2\
**Last updated:** [February 28, 2020, 8:02pm UTC](https://discourse.julialang.org/t/export-metagraph-with-node-properties/35295 "2020-02-28T20:02:24Z")

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Is there a way to export a MetaGraph to a common graph format and include the added node properties?

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## [How would I parallelize a for loop that's iterating over columns of a dataframe](https://discourse.julialang.org/t/how-would-i-parallelize-a-for-loop-thats-iterating-over-columns-of-a-dataframe/35249)

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**Author:** [@Julia1](https://discourse.julialang.org/u/Julia1)\
**Replies:** 5\
**Last updated:** [February 28, 2020, 7:37pm UTC](https://discourse.julialang.org/t/how-would-i-parallelize-a-for-loop-thats-iterating-over-columns-of-a-dataframe/35249 "2020-02-28T19:37:10Z")

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Hi how’s it going? I’ve read up on Distributed.jl, adprocs, and @everywhere. I tried implementing parallelization of a function I have by making sure all the necessary packages, functions, and variables were preceded by…

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## [TAB auto dropdown suggestions after backspace](https://discourse.julialang.org/t/tab-auto-dropdown-suggestions-after-backspace/35285)

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**Author:** [@Iulian.Cioarca](https://discourse.julialang.org/u/Iulian.Cioarca)\
**Replies:** 2\
**Last updated:** [February 28, 2020, 5:44pm UTC](https://discourse.julialang.org/t/tab-auto-dropdown-suggestions-after-backspace/35285 "2020-02-28T17:44:49Z")

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Is it possible to automatically show the TAB suggestions after one deletes the previously selected item? Example: I want to browse module A with A. + TAB. This will drop down the available function, types etc, like: A…

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## [Error in JuMP with nonlinear objective](https://discourse.julialang.org/t/error-in-jump-with-nonlinear-objective/35261)

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**Author:** [@mleprovost](https://discourse.julialang.org/u/mleprovost)\
**Replies:** 6\
**Last updated:** [February 28, 2020, 5:38pm UTC](https://discourse.julialang.org/t/error-in-jump-with-nonlinear-objective/35261 "2020-02-28T17:38:12Z")

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Hello everyone, I am interested in the following optimization problem that I would like to solve with JuMP: \\begin{split} \\min\_{x \\in \\mathbb{R}^n} & (z^Tx)^2 - \\log(b^T x\[1:k\])\\\\ \\mbox{ subject to }& x\[1:k\] \\geq 0…

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## [\[ANN\] DBInterface.jl, MySQL.jl 1.0, and SQLite.jl 1.0](https://discourse.julialang.org/t/ann-dbinterface-jl-mysql-jl-1-0-and-sqlite-jl-1-0/34701)

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**Author:** [@quinnj](https://discourse.julialang.org/u/quinnj)\
**Replies:** 5\
**Last updated:** [February 28, 2020, 3:42pm UTC](https://discourse.julialang.org/t/ann-dbinterface-jl-mysql-jl-1-0-and-sqlite-jl-1-0/34701 "2020-02-28T15:42:29Z")

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Sorry for all the posting lately, but I’ve been trying to coordinate a few 1.0 releases, so bear with me :sweat\_smile: This is the first official announcement of the new DBInterface.jl package, aiming to provide a stand…

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## [Issues using HDF5 package](https://discourse.julialang.org/t/issues-using-hdf5-package/34769)

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**Author:** [@natepage](https://discourse.julialang.org/u/natepage)\
**Replies:** 1\
**Last updated:** [February 28, 2020, 2:59pm UTC](https://discourse.julialang.org/t/issues-using-hdf5-package/34769 "2020-02-28T14:59:06Z")

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I have downloaded the HDF5 package using the “add” command and I have made a small program that currently just reads an HDF5 file and prints some of the data. However I am getting the following error when I try to run th…

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## [Serve files](https://discourse.julialang.org/t/serve-files/35229)

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**Author:** [@yakir12](https://discourse.julialang.org/u/yakir12)\
**Replies:** 1\
**Last updated:** [February 28, 2020, 2:48pm UTC](https://discourse.julialang.org/t/serve-files/35229 "2020-02-28T14:48:51Z")

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How can I serve the content of a specific folder online? Something like this: The goal is for a user to see a list of all the available files in that folder and be able to download them. The last post about this top…

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## [Python to Julia conversion](https://discourse.julialang.org/t/python-to-julia-conversion/35280)

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**Author:** [@Eldho.Ashna](https://discourse.julialang.org/u/Eldho.Ashna)\
**Replies:** 3\
**Last updated:** [February 28, 2020, 2:33pm UTC](https://discourse.julialang.org/t/python-to-julia-conversion/35280 "2020-02-28T14:33:17Z")

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Can someone tell me how to convert a python code to julia, i.e., .py to .jl.

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## [How to fit a normal distribution to some points in the tail](https://discourse.julialang.org/t/how-to-fit-a-normal-distribution-to-some-points-in-the-tail/35233)

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**Author:** [@lesshaste](https://discourse.julialang.org/u/lesshaste)\
**Replies:** 18\
**Last updated:** [February 28, 2020, 2:18pm UTC](https://discourse.julialang.org/t/how-to-fit-a-normal-distribution-to-some-points-in-the-tail/35233 "2020-02-28T14:18:48Z")

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I have some empirical values for the cdf of a distribution which should be close to Normal. These are for x = 1, 2, … , 13. They are as follows: \[5.2909066017292616e-17, 2.998035847356917e-15, 2.893916126231429e-12, 2.8…

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## [Turing/Atom incompatibilities](https://discourse.julialang.org/t/turing-atom-incompatibilities/35287)

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**Author:** [@rsteckel](https://discourse.julialang.org/u/rsteckel)\
**Replies:** 0\
**Last updated:** [February 28, 2020, 2:02pm UTC](https://discourse.julialang.org/t/turing-atom-incompatibilities/35287 "2020-02-28T14:02:38Z")

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I upgrade Julia to 1.3. I installed 2 packages (Flux and Turing). Then I started Atom and got this error: Any idea why those packages would be incompatible with Atom/Juno?

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## [Organizing code into functions—am I doing it right?](https://discourse.julialang.org/t/organizing-code-into-functions-am-i-doing-it-right/35228)

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**Author:** [@ElectronicTeaCup](https://discourse.julialang.org/u/ElectronicTeaCup)\
**Replies:** 9\
**Last updated:** [February 28, 2020, 12:46pm UTC](https://discourse.julialang.org/t/organizing-code-into-functions-am-i-doing-it-right/35228 "2020-02-28T12:46:42Z")

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Hey everyone! A while back when I was learning Python, I read the book “Think Python” which has a similar port on Julia. I read the port recently, and was wondering about the method explained in the book when it came to …

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## [How can I use Optim/BFGS on functions I can't evaluate but whose gradients I can compute?](https://discourse.julialang.org/t/how-can-i-use-optim-bfgs-on-functions-i-cant-evaluate-but-whose-gradients-i-can-compute/35160)

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**Author:** [@marius311](https://discourse.julialang.org/u/marius311)\
**Replies:** 11\
**Last updated:** [February 28, 2020, 11:24am UTC](https://discourse.julialang.org/t/how-can-i-use-optim-bfgs-on-functions-i-cant-evaluate-but-whose-gradients-i-can-compute/35160 "2020-02-28T11:24:53Z")

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Suppose I have function I want to maximize with Optim’s BFGS algorithm. While I can compute gradients for this function, I cannot compute its value (this is typical if e.g. a high-dimensional determinant is involved, sin…

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## [Deep Learning libraries](https://discourse.julialang.org/t/deep-learning-libraries/35278)

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**Author:** [@Eldho.Ashna](https://discourse.julialang.org/u/Eldho.Ashna)\
**Replies:** 2\
**Last updated:** [February 28, 2020, 10:15am UTC](https://discourse.julialang.org/t/deep-learning-libraries/35278 "2020-02-28T10:15:23Z")

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Hi everyone. I know that julia has many deep learning libraries like Flux, Mocha, Knet, MLBase etc. Can someone explain me which one is best for what. Or in other words, how are each of them different.

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## [Very mysterious error message](https://discourse.julialang.org/t/very-mysterious-error-message/35276)

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**Author:** [@moritz\_braun](https://discourse.julialang.org/u/moritz_braun)\
**Replies:** 9\
**Last updated:** [February 28, 2020, 9:47am UTC](https://discourse.julialang.org/t/very-mysterious-error-message/35276 "2020-02-28T09:47:17Z")

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The following code file=ARGS\[1\] lines=readlines(file) lenFile=length(lines) l3=lines\[3\] l4=lines\[4\] l5=lines\[5\] l6=lines\[6\] sl3=split(l3) NA=parse(Int64,sl3\[1\]) sl4=split(l4) nx=parse(Int64,sl4\[1\]) sl5=split(l…

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## [Official Docker Hub Julia Images?](https://discourse.julialang.org/t/official-docker-hub-julia-images/18358)

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**Author:** [@ccoffrin](https://discourse.julialang.org/u/ccoffrin)\
**Replies:** 8\
**Last updated:** [February 28, 2020, 7:48am UTC](https://discourse.julialang.org/t/official-docker-hub-julia-images/18358 "2020-02-28T07:48:42Z")

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Is one of these two docker hub images an official base for the Julia language? https://hub.docker.com/r/\_/julia/ https://hub.docker.com/r/julialang/julia/

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## [Installing packages leads to crash](https://discourse.julialang.org/t/installing-packages-leads-to-crash/35268)

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**Author:** [@soylentgreeen202](https://discourse.julialang.org/u/soylentgreeen202)\
**Replies:** 1\
**Last updated:** [February 28, 2020, 6:08am UTC](https://discourse.julialang.org/t/installing-packages-leads-to-crash/35268 "2020-02-28T06:08:25Z")

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Hello, I just installed Julia for the first time but am unable to install any packages. I am running Julia 1.3 on Arch linux. edit: it looks like upgrading from http-parser 2.9.2 to 2.9.3 is what’s causing this for me. …

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## [Help me with indexing](https://discourse.julialang.org/t/help-me-with-indexing/35203)

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**Author:** [@varun\_yaramasu](https://discourse.julialang.org/u/varun_yaramasu)\
**Replies:** 3\
**Last updated:** [February 28, 2020, 4:12am UTC](https://discourse.julialang.org/t/help-me-with-indexing/35203 "2020-02-28T04:12:15Z")

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For example using JuMP,SCS m=Model(with\_optimizer(SCS.Optimizer)) branch=\[1 2 0.1 3 4 0.1 4 5 0.2 4 6 0.3 5 6 0.1 \] G=length(branch\[:,1\]) @variable(m,P\[branch\[1:G,1\], branch\[1…

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## [How to control the output of broadcast?](https://discourse.julialang.org/t/how-to-control-the-output-of-broadcast/32287)

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**Author:** [@tomtom](https://discourse.julialang.org/u/tomtom)\
**Replies:** 7\
**Last updated:** [February 28, 2020, 1:23am UTC](https://discourse.julialang.org/t/how-to-control-the-output-of-broadcast/32287 "2020-02-28T01:23:58Z")

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calling fun.() below returns an Array of NamedTuples: julia\> function fun(x)::NamedTuple (a = x + 1, b = x - 1) end fun (generic function with 1 method) julia\> fun.(\[1, 2, 3\]) 3-element Array{NamedTup…

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## [Entering xlsx columns into HypothosisTests](https://discourse.julialang.org/t/entering-xlsx-columns-into-hypothosistests/35157)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 26\
**Last updated:** [February 27, 2020, 10:55pm UTC](https://discourse.julialang.org/t/entering-xlsx-columns-into-hypothosistests/35157 "2020-02-27T22:55:59Z")

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I’m trying to do Chi Squared tests of variables in a dataframe, from an xlsx file. When I use describe() I get a table: ────┼─────────┼──────────┼──────────┤ │ 1 │ Q1 │ 1.47727 │ 1 │ 1.0 │ 2 │ 2 …

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## [No matching method in 02-advanced\_ODE\_solving.ipynb tutorial](https://discourse.julialang.org/t/no-matching-method-in-02-advanced-ode-solving-ipynb-tutorial/35200)

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**Author:** [@erlebach](https://discourse.julialang.org/u/erlebach)\
**Replies:** 17\
**Last updated:** [February 27, 2020, 10:25pm UTC](https://discourse.julialang.org/t/no-matching-method-in-02-advanced-ode-solving-ipynb-tutorial/35200 "2020-02-27T22:25:53Z")

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Hi, I am running a tutorial: 02-advanced\_ODE\_solving in a Jupyter notebook. I got part of the way down the notebook, and eventually got an error that indicated a routine was not found. I am using Julia 1.31 . If there i…

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## [Problem of first plot? can be better?](https://discourse.julialang.org/t/problem-of-first-plot-can-be-better/35064)

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**Author:** [@Darione](https://discourse.julialang.org/u/Darione)\
**Replies:** 10\
**Last updated:** [February 27, 2020, 10:25pm UTC](https://discourse.julialang.org/t/problem-of-first-plot-can-be-better/35064 "2020-02-27T22:25:37Z")

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Is there an improvement in the first plot problem in Julia’s road map? I ported a text search program, with its web interface (with Genie) and it works very well, a missile like speed once the first compilation started …

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## [Method definition overwritten warnings when compiling cache or "using module" twice](https://discourse.julialang.org/t/method-definition-overwritten-warnings-when-compiling-cache-or-using-module-twice/28970)

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**Author:** [@rwgardner](https://discourse.julialang.org/u/rwgardner)\
**Replies:** 1\
**Last updated:** [February 27, 2020, 9:56pm UTC](https://discourse.julialang.org/t/method-definition-overwritten-warnings-when-compiling-cache-or-using-module-twice/28970 "2020-02-27T21:56:50Z")

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I have some code with this general structure push!(LOAD\_PATH, Base.source\_dir()) …

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