# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1751

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

**Page:** 1752

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## [Benchmark Kuramoto-Sivashinsky DiffEq](https://discourse.julialang.org/t/benchmark-kuramoto-sivashinsky-diffeq/39196)

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**Author:** [@mleprovost](https://discourse.julialang.org/u/mleprovost)\
**Replies:** 1\
**Last updated:** [May 10, 2020, 1:38am UTC](https://discourse.julialang.org/t/benchmark-kuramoto-sivashinsky-diffeq/39196 "2020-05-10T01:38:13Z")

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Hello, I have been looking at the notebook KS FDM Work-Precision Diagrams that solves the Kuramot-Sivashinsky (KS) problem with finite differences. The 1D equation is: \\frac{\\partial u}{\\partial t} + u \\frac{\\partial…

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## [\`Base.accumulate\`, but with initial value](https://discourse.julialang.org/t/base-accumulate-but-with-initial-value/39203)

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**Author:** [@goretkin](https://discourse.julialang.org/u/goretkin)\
**Replies:** 3\
**Last updated:** [May 10, 2020, 1:24am UTC](https://discourse.julialang.org/t/base-accumulate-but-with-initial-value/39203 "2020-05-10T01:24:50Z")

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Base.accumulate satisfies length(accumulate(op, input)) == length(input) I’m looking for a very similar function that satisfies length(accumulate(op, input; \[init\])) == length(input) + 1 and isequal(last(accumulate′…

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## [\[ANN\] DependencyWalker: walk through your binary shared libraries](https://discourse.julialang.org/t/ann-dependencywalker-walk-through-your-binary-shared-libraries/39204)

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**Author:** [@giordano](https://discourse.julialang.org/u/giordano)\
**Replies:** 0\
**Last updated:** [May 10, 2020, 12:36am UTC](https://discourse.julialang.org/t/ann-dependencywalker-walk-through-your-binary-shared-libraries/39204 "2020-05-10T00:36:41Z")

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This is to announce the first release of DependencyWalker.jl. No, this isn’t a tool to visualise the dependencies of your Julia libraries, but a very small package (less than 100 sloc!) to walk through the dependencies …

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## [Alternative to reading m4a files](https://discourse.julialang.org/t/alternative-to-reading-m4a-files/39194)

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**Author:** [@bafonso](https://discourse.julialang.org/u/bafonso)\
**Replies:** 2\
**Last updated:** [May 9, 2020, 11:53pm UTC](https://discourse.julialang.org/t/alternative-to-reading-m4a-files/39194 "2020-05-09T23:53:51Z")

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I am currently having another go at Julia and decided to do a small project working on audio data. Currently running into the situation of not being able to read m4a files. These are coming from my OSX setup and I am doi…

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## [Function not able to dispatch to a method I believed was defined](https://discourse.julialang.org/t/function-not-able-to-dispatch-to-a-method-i-believed-was-defined/39201)

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**Author:** [@korowjev](https://discourse.julialang.org/u/korowjev)\
**Replies:** 2\
**Last updated:** [May 9, 2020, 11:40pm UTC](https://discourse.julialang.org/t/function-not-able-to-dispatch-to-a-method-i-believed-was-defined/39201 "2020-05-09T23:40:55Z")

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Say I defined julia\> f(x::Number, g) = g(x) f (generic function with 1 method) julia\> f(x::Array{Number, 1}, g) = f.(x) f (generic function with 2 methods) julia\> g(x) = 2x g (generic function with 1 method) When cal…

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## [What is the use case for Julia docker images?](https://discourse.julialang.org/t/what-is-the-use-case-for-julia-docker-images/39152)

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**Author:** [@fergu](https://discourse.julialang.org/u/fergu)\
**Replies:** 10\
**Last updated:** [May 9, 2020, 11:19pm UTC](https://discourse.julialang.org/t/what-is-the-use-case-for-julia-docker-images/39152 "2020-05-09T23:19:49Z")

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This is half a question about Julia, half a question about Docker. Framing it in this way is what I think will be best for my comprehension though. There are maintained Julia images on Dockerhub (See here). I get that y…

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## [Julia in Toulouse](https://discourse.julialang.org/t/julia-in-toulouse/36943)

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**Author:** [@d9w](https://discourse.julialang.org/u/d9w)\
**Replies:** 5\
**Last updated:** [May 9, 2020, 10:02pm UTC](https://discourse.julialang.org/t/julia-in-toulouse/36943 "2020-05-09T22:02:00Z")

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Hi! Are there others here from Toulouse who would like to do a meetup soon? We could start with a virtual one and plan a physical meetup for later on.

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## [Julia vs Microsoft's (Rust-inspired) Verona language and e.g. snmalloc allocator](https://discourse.julialang.org/t/julia-vs-microsofts-rust-inspired-verona-language-and-e-g-snmalloc-allocator/38610)

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**Author:** [@Palli](https://discourse.julialang.org/u/Palli)\
**Replies:** 13\
**Last updated:** [May 9, 2020, 9:44pm UTC](https://discourse.julialang.org/t/julia-vs-microsofts-rust-inspired-verona-language-and-e-g-snmalloc-allocator/38610 "2020-05-09T21:44:06Z")

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The research project doesn’t mean “Microsoft is no longer using C++/C#/Rust”. See under C. The project is meant to be learned from, to integrate the ideas into other languages. I’m not sure if it’s possible to add to Ju…

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## [Fused ternary operator?](https://discourse.julialang.org/t/fused-ternary-operator/3067)

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**Author:** [@marius311](https://discourse.julialang.org/u/marius311)\
**Replies:** 6\
**Last updated:** [May 9, 2020, 9:40pm UTC](https://discourse.julialang.org/t/fused-ternary-operator/3067 "2020-05-09T21:40:03Z")

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Am I right there’s no “easy” way to broadcast the ternary operator? E.g. x = \[0,1,2\] @. x==0 ? 0. : 1/x #this doesn't work Of course, its easy enough to write the code yourself, broadcast(x-\>(x==0 ? 0. : 1/x), \[0,1,…

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## [Revise cannot transform my dataset](https://discourse.julialang.org/t/revise-cannot-transform-my-dataset/39177)

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**Author:** [@chedieck](https://discourse.julialang.org/u/chedieck)\
**Replies:** 23\
**Last updated:** [May 9, 2020, 9:17pm UTC](https://discourse.julialang.org/t/revise-cannot-transform-my-dataset/39177 "2020-05-09T21:17:58Z")

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I am trying to solve the “Predict Data Sales” on kaggle, using the DataFrames, Plots and CSV packages. Here is my code, named processdata.jl, so far: @time using CSV, DataFrames, Plots println("finished importing") # # …

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## [Julia-like compiled languages](https://discourse.julialang.org/t/julia-like-compiled-languages/39134)

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**Author:** [@cortner](https://discourse.julialang.org/u/cortner)\
**Replies:** 10\
**Last updated:** [May 9, 2020, 8:51pm UTC](https://discourse.julialang.org/t/julia-like-compiled-languages/39134 "2020-05-09T20:51:00Z")

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I’m putting this under “off-topic” since it doesn’t fit into usage categories, but I do believe this is a question relevant for the Julia community. My situation is that I’m developing a class of models in Julia which I…

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## [Pkg.add() fails because registry folder is read-only](https://discourse.julialang.org/t/pkg-add-fails-because-registry-folder-is-read-only/38592)

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**Author:** [@qingyanz](https://discourse.julialang.org/u/qingyanz)\
**Replies:** 2\
**Last updated:** [May 9, 2020, 8:48pm UTC](https://discourse.julialang.org/t/pkg-add-fails-because-registry-folder-is-read-only/38592 "2020-05-09T20:48:42Z")

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Hello, I am new to Julia, and I recently downloaded JuliaPro 1.0.5 on a new computer. However, I ran into trouble with Pkg.add() just into the third line, and none of the threads on julialang.org, stackexchange or GitHub…

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## [\[ANN\] LightGraphs v1.3.3 - another bugfix](https://discourse.julialang.org/t/ann-lightgraphs-v1-3-3-another-bugfix/39191)

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**Author:** [@anon94023334](https://discourse.julialang.org/u/anon94023334)\
**Replies:** 0\
**Last updated:** [May 9, 2020, 6:59pm UTC](https://discourse.julialang.org/t/ann-lightgraphs-v1-3-3-another-bugfix/39191 "2020-05-09T18:59:26Z")

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Hi all, LightGraphs.jl has been updated to v1.3.3 to fix a bug in core\_number. No other changes have been made. I expect to have a cool LG announcement in the next few days. Please stay tuned :smiley:. Edited to add m…

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## [Access to content of object in Julia](https://discourse.julialang.org/t/access-to-content-of-object-in-julia/39195)

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**Author:** [@sergevic](https://discourse.julialang.org/u/sergevic)\
**Replies:** 2\
**Last updated:** [May 9, 2020, 8:06pm UTC](https://discourse.julialang.org/t/access-to-content-of-object-in-julia/39195 "2020-05-09T20:06:26Z")

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How can I display the names of elements stored in an object in Julia? For example, in R, we have the command names() which displays the names of those elements. In Julia, the command eigen(A) stores the eigenvalues in va…

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## [Inline function on transform](https://discourse.julialang.org/t/inline-function-on-transform/39176)

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**Author:** [@chedieck](https://discourse.julialang.org/u/chedieck)\
**Replies:** 1\
**Last updated:** [May 9, 2020, 7:52pm UTC](https://discourse.julialang.org/t/inline-function-on-transform/39176 "2020-05-09T19:52:23Z")

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So, I am using the DataFrames package and have this dataset called salestrain that has a column called date. Now date is a column of strings representing the date of the sales, each is written like "12.10.2014"; but I’m …

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## [Registering a new package and naming convention](https://discourse.julialang.org/t/registering-a-new-package-and-naming-convention/39184)

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**Author:** [@Andrea\_Vigliotti](https://discourse.julialang.org/u/Andrea_Vigliotti)\
**Replies:** 2\
**Last updated:** [May 9, 2020, 7:14pm UTC](https://discourse.julialang.org/t/registering-a-new-package-and-naming-convention/39184 "2020-05-09T19:14:13Z")

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Hi all, (first time I try to register a package) I would like to register a package called AD4SM.jl, but I understand it violates one of the package naming conventions (ends with a upper case letter). The automatic re…

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## [Future-proof way to save and load data](https://discourse.julialang.org/t/future-proof-way-to-save-and-load-data/39148)

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**Author:** [@BioTurboNick](https://discourse.julialang.org/u/BioTurboNick)\
**Replies:** 12\
**Last updated:** [May 9, 2020, 4:06pm UTC](https://discourse.julialang.org/t/future-proof-way-to-save-and-load-data/39148 "2020-05-09T16:06:19Z")

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I’m frustrated with JLD2, which I thought was the way to save/load data, but it’s reconstructed types aren’t playing well with my types. But I just ran across a post from a year ago suggesting JLD2 is effectively abando…

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## [error loading packages in juliabox ](https://discourse.julialang.org/t/error-loading-packages-in-juliabox/18690)

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**Author:** [@Ahmed\_Hussein](https://discourse.julialang.org/u/Ahmed_Hussein)\
**Replies:** 2\
**Last updated:** [May 9, 2020, 3:44pm UTC](https://discourse.julialang.org/t/error-loading-packages-in-juliabox/18690 "2020-05-09T15:44:52Z")

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i am getting this error when trying to load metalhead or flux in juliabox LoadError: LoadError: could not open file /mnt/juliabox/.julia/packages/ZipFile/p60bh/deps/deps.jl Stacktrace: \[1\] include at ./boot.jl:317 \[in…

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## ["Ternary operator", (?:) associates from right to left?](https://discourse.julialang.org/t/ternary-operator-associates-from-right-to-left/39179)

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**Author:** [@GerhardTotschnig](https://discourse.julialang.org/u/GerhardTotschnig)\
**Replies:** 5\
**Last updated:** [May 9, 2020, 3:20pm UTC](https://discourse.julialang.org/t/ternary-operator-associates-from-right-to-left/39179 "2020-05-09T15:20:15Z")

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In the manual ist is written for the ternary operator a ? b : c “to facilitate chaining, the operator associates from right to left.” See: https://docs.julialang.org/en/latest/manual/control-flow/#man-conditional-eval…

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## [Get POST parameters using a HTTP server](https://discourse.julialang.org/t/get-post-parameters-using-a-http-server/39113)

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**Author:** [@dmolina](https://discourse.julialang.org/u/dmolina)\
**Replies:** 5\
**Last updated:** [May 9, 2020, 1:52pm UTC](https://discourse.julialang.org/t/get-post-parameters-using-a-http-server/39113 "2020-05-09T13:52:14Z")

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Dear all, I want to do a small server using Julia. This service implies to receive POST parameters and returns a file. Because I want to include it inside my package, I have chosen HTTP.jl (instead of Genie) to reduce t…

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## ["memory mapping failed" when reading many CSVs](https://discourse.julialang.org/t/memory-mapping-failed-when-reading-many-csvs/27979)

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**Author:** [@aplavin](https://discourse.julialang.org/u/aplavin)\
**Replies:** 11\
**Last updated:** [May 8, 2020, 5:59pm UTC](https://discourse.julialang.org/t/memory-mapping-failed-when-reading-many-csvs/27979 "2020-05-08T17:59:13Z")

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I use CSV.jl for reading many small CSV files, and at some point always encounter the following: “ERROR: SystemError: memory mapping failed: Cannot allocate memory”. Of course, there is plenty of free memory at the time.…

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## [Revise and import](https://discourse.julialang.org/t/revise-and-import/23319)

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**Author:** [@dhazeghi](https://discourse.julialang.org/u/dhazeghi)\
**Replies:** 3\
**Last updated:** [May 9, 2020, 12:52pm UTC](https://discourse.julialang.org/t/revise-and-import/23319 "2020-05-09T12:52:12Z")

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Hi folks, a fairly basic question on Revise.jl usage: how should I use revise with packages (mine) that import other packages? For example: julia\> using Revise julia\> import MyPackage \<edit code in package imported by…

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## [Trying to write a parquet writer. Please help!](https://discourse.julialang.org/t/trying-to-write-a-parquet-writer-please-help/38653)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 1\
**Last updated:** [May 9, 2020, 12:06pm UTC](https://discourse.julialang.org/t/trying-to-write-a-parquet-writer-please-help/38653 "2020-05-09T12:06:15Z")

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I am trying to understand enough about parquet to get a parquet writer going. I am trying to read a parquet file and I am using Thrift.jl. It says at offset 4 there is DictionaryPageHeader so I read that using Thrift.jl…

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## [How do you drop one quote inside another?](https://discourse.julialang.org/t/how-do-you-drop-one-quote-inside-another/39078)

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**Author:** [@djsegal](https://discourse.julialang.org/u/djsegal)\
**Replies:** 4\
**Last updated:** [May 9, 2020, 11:55am UTC](https://discourse.julialang.org/t/how-do-you-drop-one-quote-inside-another/39078 "2020-05-09T11:55:06Z")

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In the following pseudocode, is it possible to drop the foo quote inside the fizzbuzz function? bar = quote foo = quote i = rand() j = 7 end function fizzbuzz() # want foo here k = i \* j end end…

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## [Regex: ERROR: PCRE error: requested value is not set](https://discourse.julialang.org/t/regex-error-pcre-error-requested-value-is-not-set/39170)

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**Author:** [@D4taV1s](https://discourse.julialang.org/u/D4taV1s)\
**Replies:** 4\
**Last updated:** [May 9, 2020, 10:32am UTC](https://discourse.julialang.org/t/regex-error-pcre-error-requested-value-is-not-set/39170 "2020-05-09T10:32:40Z")

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task: apply regex to a multi-line string each like only some line contain a custom tag only apply a substitution to the line that contain that field, and blank out all the other lines (data extraction) current regex .…

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## [Will decreasing the precision of intermediate variables improve performance of code?](https://discourse.julialang.org/t/will-decreasing-the-precision-of-intermediate-variables-improve-performance-of-code/39166)

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**Author:** [@SambitMishra98](https://discourse.julialang.org/u/SambitMishra98)\
**Replies:** 12\
**Last updated:** [May 9, 2020, 9:47am UTC](https://discourse.julialang.org/t/will-decreasing-the-precision-of-intermediate-variables-improve-performance-of-code/39166 "2020-05-09T09:47:48Z")

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I found from a Youtube video that half-precision is significantly faster than single and double precision. \[JuliaCon 2018 | Keynote - Tricks and Tips in Numerical Computing | Nick Higham - YouTube\](2018 | Keynote - Trick…

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## [Difficulties with vectorized logical operations due to operator precedence](https://discourse.julialang.org/t/difficulties-with-vectorized-logical-operations-due-to-operator-precedence/39137)

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**Author:** [@CameronBieganek](https://discourse.julialang.org/u/CameronBieganek)\
**Replies:** 7\
**Last updated:** [May 9, 2020, 8:08am UTC](https://discourse.julialang.org/t/difficulties-with-vectorized-logical-operations-due-to-operator-precedence/39137 "2020-05-09T08:08:41Z")

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I run into this problem all the time. Here’s an example where the vector x contains two kinds of missing, the missing singleton and a sentinel value of 99. julia\> x = \[1, 99, missing, 99, 2, missing, 1\]; julia\> xmissin…

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## [The "first post" tips needs to be more visible and possibly emailed to new users](https://discourse.julialang.org/t/the-first-post-tips-needs-to-be-more-visible-and-possibly-emailed-to-new-users/38965)

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**Author:** [@anon94023334](https://discourse.julialang.org/u/anon94023334)\
**Replies:** 1\
**Last updated:** [May 9, 2020, 7:16am UTC](https://discourse.julialang.org/t/the-first-post-tips-needs-to-be-more-visible-and-possibly-emailed-to-new-users/38965 "2020-05-09T07:16:24Z")

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I can’t seem to find the pinned “here’s how to make a good post here” topic. I keep losing it and can’t remember what forum it’s in. In any case, we continue to have new users who make posts that are difficult to respond…

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## [How to read and understand Julia documentation](https://discourse.julialang.org/t/how-to-read-and-understand-julia-documentation/39122)

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**Author:** [@Oto\_Brzobohaty](https://discourse.julialang.org/u/Oto_Brzobohaty)\
**Replies:** 3\
**Last updated:** [May 9, 2020, 5:53am UTC](https://discourse.julialang.org/t/how-to-read-and-understand-julia-documentation/39122 "2020-05-09T05:53:01Z")

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1. Example: I tried to use Optim package to implement MATLAB fminsearch I have found it in the Optim documentation and I tried to follow it: using Optim struct MatlabSimplexer \<: Optim.Simplexer a::Float64 b::…

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## [A implementation of ResNet-18 uses lot of GPU memory](https://discourse.julialang.org/t/a-implementation-of-resnet-18-uses-lot-of-gpu-memory/36389)

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**Author:** [@OTapio](https://discourse.julialang.org/u/OTapio)\
**Replies:** 10\
**Last updated:** [May 9, 2020, 5:50am UTC](https://discourse.julialang.org/t/a-implementation-of-resnet-18-uses-lot-of-gpu-memory/36389 "2020-05-09T05:50:22Z")

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I have been trying to create ResNet-18 on Julia. I have managed to create a functional one but it is slow and uses lot of GPU memory. This is puzzling since similar architecture on Tensorflow runs 5-10 times faster and u…

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