# General Usage

**URL:** https://discourse.julialang.org/c/usage/6.md?page=931

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

**Page:** 932

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## [Install PyCall on travis](https://discourse.julialang.org/t/install-pycall-on-travis/15921)

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**Author:** [@fincardona](https://discourse.julialang.org/u/fincardona)\
**Replies:** 5\
**Last updated:** [October 8, 2018, 11:26am UTC](https://discourse.julialang.org/t/install-pycall-on-travis/15921 "2018-10-08T11:26:51Z")

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Hello! I’m trying to develop a package for Julia which calls Astropy through PyCall. How can I install PyCall on travis? thanks a lot

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## [Missing libpython3.5m library?](https://discourse.julialang.org/t/missing-libpython3-5m-library/16007)

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**Author:** [@purplishrock](https://discourse.julialang.org/u/purplishrock)\
**Replies:** 1\
**Last updated:** [October 8, 2018, 5:21am UTC](https://discourse.julialang.org/t/missing-libpython3-5m-library/16007 "2018-10-08T05:21:41Z")

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‘’’ \[ Info: Precompiling PyPlot \[d330b81b-6aea-500a-939a-2ce795aea3ee\] ERROR: LoadError: LoadError: could not load library “libpython3.5m” libpython3.5m.so: cannot open shared object file: No such file or directory ‘…

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## [Optional dependencies and name collisions](https://discourse.julialang.org/t/optional-dependencies-and-name-collisions/15997)

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**Author:** [@pablosanjose](https://discourse.julialang.org/u/pablosanjose)\
**Replies:** 6\
**Last updated:** [October 7, 2018, 11:56pm UTC](https://discourse.julialang.org/t/optional-dependencies-and-name-collisions/15997 "2018-10-07T23:56:32Z")

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Say I am developing package MyPkg that computes some stuff using an exported type TA. The package also contains an optional dependency on Makie, implemented with Requires.jl. After my computation using MyPkg, I do using…

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## [Help understanding PyCall-related Travis failure](https://discourse.julialang.org/t/help-understanding-pycall-related-travis-failure/15957)

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**Author:** [@crbinz](https://discourse.julialang.org/u/crbinz)\
**Replies:** 6\
**Last updated:** [October 7, 2018, 11:10pm UTC](https://discourse.julialang.org/t/help-understanding-pycall-related-travis-failure/15957 "2018-10-07T23:10:37Z")

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I made a fairly trivial commit in SGP4.jl (removing \_\_precompile\_\_(), but now the CI is failing – apparently PyCall can’t find the sgp4 python module, although it appears that the SGP4.jl build process installs it proper…

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## [Installing CSV on Julia 0.6.x](https://discourse.julialang.org/t/installing-csv-on-julia-0-6-x/15995)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 3\
**Last updated:** [October 7, 2018, 10:10pm UTC](https://discourse.julialang.org/t/installing-csv-on-julia-0-6-x/15995 "2018-10-07T22:10:53Z")

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I am getting the following warning when precompiling the package CSV: julia\> using CSV INFO: Precompiling module CSV. WARNING: static parameter R does not occur in signature for catvaluetype at /home/ufechner/.julia/v0.…

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## [Julia on NetBSD / Minix?](https://discourse.julialang.org/t/julia-on-netbsd-minix/15985)

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**Author:** [@chakravala](https://discourse.julialang.org/u/chakravala)\
**Replies:** 0\
**Last updated:** [October 7, 2018, 4:59am UTC](https://discourse.julialang.org/t/julia-on-netbsd-minix/15985 "2018-10-07T04:59:54Z")

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Are there any users here who have tried out installing / compiling Julia on NetBSD or on Minix? If so, please share your experiences

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## [Is there way to change default order of markers in Plots.jl?](https://discourse.julialang.org/t/is-there-way-to-change-default-order-of-markers-in-plots-jl/15984)

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**Author:** [@djsegal](https://discourse.julialang.org/u/djsegal)\
**Replies:** 0\
**Last updated:** [October 7, 2018, 4:52am UTC](https://discourse.julialang.org/t/is-there-way-to-change-default-order-of-markers-in-plots-jl/15984 "2018-10-07T04:52:14Z")

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Just not a big fan of triangle markers :confused: Is there a way to change the :auto order for markers? // this occurs when you need to do hacky stuff to get a plot to work (most recently, to make colored scatters wor…

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## [Zeros slower than Array comprehension](https://discourse.julialang.org/t/zeros-slower-than-array-comprehension/15980)

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**Author:** [@antcap96](https://discourse.julialang.org/u/antcap96)\
**Replies:** 3\
**Last updated:** [October 7, 2018, 1:37am UTC](https://discourse.julialang.org/t/zeros-slower-than-array-comprehension/15980 "2018-10-07T01:37:02Z")

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When testing some things in the REPL I tried creating a 100x100 matrix of zeros and found it strange that the built-in zeros was slower than creating such a matrix using a Array comprehension. julia\> @btime zeros(Float6…

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## [Understanding allocations](https://discourse.julialang.org/t/understanding-allocations/15967)

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**Author:** [@rveltz](https://discourse.julialang.org/u/rveltz)\
**Replies:** 2\
**Last updated:** [October 6, 2018, 5:20pm UTC](https://discourse.julialang.org/t/understanding-allocations/15967 "2018-10-06T17:20:48Z")

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Hi, I have troubles understanding why foo allocates whereas foo does not: 1.623 ms (65804 allocations: 1.18 MiB) 7.578 μs (0 allocations: 0 bytes) Does someone know why? Thank you, using Parameters, BenchmarkTool…

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## [Value of e](https://discourse.julialang.org/t/value-of-e/15958)

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**Author:** [@Ajaychat3](https://discourse.julialang.org/u/Ajaychat3)\
**Replies:** 3\
**Last updated:** [October 6, 2018, 2:43pm UTC](https://discourse.julialang.org/t/value-of-e/15958 "2018-10-06T14:43:19Z")

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how to get around this? julia 1.0\> e ERROR: UndefVarError: e not defined julia 1.0\> pi π = 3.1415926535897... julia 1.0\> golden ERROR: UndefVarError: golden not defined

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## [What does \`SYSTEM: show(lasterr) caused an error\` mean ?](https://discourse.julialang.org/t/what-does-system-show-lasterr-caused-an-error-mean/15705)

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**Author:** [@ben](https://discourse.julialang.org/u/ben)\
**Replies:** 3\
**Last updated:** [October 6, 2018, 2:41pm UTC](https://discourse.julialang.org/t/what-does-system-show-lasterr-caused-an-error-mean/15705 "2018-10-06T14:41:15Z")

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Hello, Today I had this error: SYSTEM: show(lasterr) caused an error KeyError(:default) I forgot to put a double == instead of a = for a comparison. Ok, maybe I am stupid BUT it is not very friendly for the REPL to th…

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## [Parsing and generating C code](https://discourse.julialang.org/t/parsing-and-generating-c-code/15959)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 6\
**Last updated:** [October 6, 2018, 2:34pm UTC](https://discourse.julialang.org/t/parsing-and-generating-c-code/15959 "2018-10-06T14:34:14Z")

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Hello, I have a very small task to solve and want to do it with Julia: Removing curtain functions from a C code module. The names of the functions to remove are given as string list, there is an input file and an outpu…

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## [How to download content and calculate statistics of words on websites](https://discourse.julialang.org/t/how-to-download-content-and-calculate-statistics-of-words-on-websites/15929)

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**Author:** [@programista](https://discourse.julialang.org/u/programista)\
**Replies:** 1\
**Last updated:** [October 6, 2018, 10:50am UTC](https://discourse.julialang.org/t/how-to-download-content-and-calculate-statistics-of-words-on-websites/15929 "2018-10-06T10:50:17Z")

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How to start ? downloading content and prepare statistics of words (all) on websites. For me now it is a new topic, some packages? Paul

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## [Which functions do yield?](https://discourse.julialang.org/t/which-functions-do-yield/15962)

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**Author:** [@tobias.knopp](https://discourse.julialang.org/u/tobias.knopp)\
**Replies:** 0\
**Last updated:** [October 6, 2018, 10:02am UTC](https://discourse.julialang.org/t/which-functions-do-yield/15962 "2018-10-06T10:02:44Z")

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Is there somewhere a documented list of functions that do yield?

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## [Boolean indexing does not work](https://discourse.julialang.org/t/boolean-indexing-does-not-work/15692)

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**Author:** [@aplavin](https://discourse.julialang.org/u/aplavin)\
**Replies:** 4\
**Last updated:** [October 5, 2018, 8:55pm UTC](https://discourse.julialang.org/t/boolean-indexing-does-not-work/15692 "2018-10-05T20:55:46Z")

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Reading the documentation I see that boolean indexing is supposed to be the same as indexing with findall(...). However, it doesn’t look like this is correct: A = randn(10, 20, 30) mask = dropdims(sum(A, dims=3), dims=3…

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## [Constants like e and eulergamma in Julia V1.0 no longer available?](https://discourse.julialang.org/t/constants-like-e-and-eulergamma-in-julia-v1-0-no-longer-available/15917)

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**Author:** [@Gunter\_Faes](https://discourse.julialang.org/u/Gunter_Faes)\
**Replies:** 12\
**Last updated:** [October 5, 2018, 8:03pm UTC](https://discourse.julialang.org/t/constants-like-e-and-eulergamma-in-julia-v1-0-no-longer-available/15917 "2018-10-05T20:03:23Z")

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Hello, I am currently working my way through the Julia documentation and the examples and stumble over the Euler number e. In Julia V0.6 I could still call them, but in Julia V1.0.1 I get the message “ERROR: UndefVarErr…

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## [Export csv - CSV.jl and CSVFiles do not help](https://discourse.julialang.org/t/export-csv-csv-jl-and-csvfiles-do-not-help/15900)

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**Author:** [@juliauser](https://discourse.julialang.org/u/juliauser)\
**Replies:** 9\
**Last updated:** [October 5, 2018, 7:50pm UTC](https://discourse.julialang.org/t/export-csv-csv-jl-and-csvfiles-do-not-help/15900 "2018-10-05T19:50:04Z")

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Hi, I have a 90000 x 414 DataFrame I need to export to Stats. I tried saving it as csv using CSV and CSVFiles but Julia gets stuck and I have to stop it. This happens even if I try with many fewer rows. Any advice? Inc…

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## [Pkg3/Julia 1.0 - how to \`dev\` a specific branch of unregistered package?](https://discourse.julialang.org/t/pkg3-julia-1-0-how-to-dev-a-specific-branch-of-unregistered-package/15927)

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**Author:** [@anon32405968](https://discourse.julialang.org/u/anon32405968)\
**Replies:** 12\
**Last updated:** [October 5, 2018, 6:30pm UTC](https://discourse.julialang.org/t/pkg3-julia-1-0-how-to-dev-a-specific-branch-of-unregistered-package/15927 "2018-10-05T18:30:04Z")

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In the pkg mode of the Julia 1.0 REPL I can do the following to get add a specific branch of my unregistered package: (v1.0) pkg\> add https://github.com/JuliaRheology/RHEOS.jl#v1compat However, if I want to dev a speci…

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## [\`resolve\` removes packages under \[extra\] from Manifest](https://discourse.julialang.org/t/resolve-removes-packages-under-extra-from-manifest/15937)

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**Author:** [@e3c6](https://discourse.julialang.org/u/e3c6)\
**Replies:** 1\
**Last updated:** [October 5, 2018, 5:54pm UTC](https://discourse.julialang.org/t/resolve-removes-packages-under-extra-from-manifest/15937 "2018-10-05T17:54:22Z")

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It seems that resolve removes packages under \[extra\] (in Project.toml) from the Manifest.toml. Is this intended behavior? It implies that instante’ing a package is not enough to make it testable, and that packages that …

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## [From baremodule to Dict](https://discourse.julialang.org/t/from-baremodule-to-dict/10744)

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**Author:** [@scelles](https://discourse.julialang.org/u/scelles)\
**Replies:** 9\
**Last updated:** [October 5, 2018, 12:36pm UTC](https://discourse.julialang.org/t/from-baremodule-to-dict/10744 "2018-10-05T12:36:50Z")

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Hello, I defined a baremodule baremodule Return const INVALID\_CMD = 0x00 const CMD\_FINISHED = 0x01 end I would like to get a Dict from this module with keys being 0x00 and 0x01 (and more …) How can I …

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## [Using DataFrames on J 1.0.1 : now 5-7 seconds](https://discourse.julialang.org/t/using-dataframes-on-j-1-0-1-now-5-7-seconds/15915)

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**Author:** [@iwelch](https://discourse.julialang.org/u/iwelch)\
**Replies:** 0\
**Last updated:** [October 5, 2018, 6:27am UTC](https://discourse.julialang.org/t/using-dataframes-on-j-1-0-1-now-5-7-seconds/15915 "2018-10-05T06:27:50Z")

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Related to my old post Using DataFrames: ~ 10 seconds . Is there a remedy in sight for julia\> @time using DataFrames ~ 5-9 seconds (iMac and 4-year old Macbook Pro) I believe this was on the agenda.

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## [How do I reinterpret and reshape a multi-dimensional array \`J\` into a two-dimensional array \`j\` such that \`typeof(j) \<: Matrix\` is true in Julia 0.7](https://discourse.julialang.org/t/how-do-i-reinterpret-and-reshape-a-multi-dimensional-array-j-into-a-two-dimensional-array-j-such-that-typeof-j-matrix-is-true-in-julia-0-7/15911)

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**Author:** [@zygmuntszpak](https://discourse.julialang.org/u/zygmuntszpak)\
**Replies:** 2\
**Last updated:** [October 5, 2018, 5:08am UTC](https://discourse.julialang.org/t/how-do-i-reinterpret-and-reshape-a-multi-dimensional-array-j-into-a-two-dimensional-array-j-such-that-typeof-j-matrix-is-true-in-julia-0-7/15911 "2018-10-05T05:08:06Z")

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When upgrading code from version 0.6.4 to 0.7.0 I came across the following issue: Julia 0.6.4 J = rand(4,10,12) j = reinterpret(Float64,J,(4\*10,12)) typeof(j) \<: Matrix # Evaluates to true Julia 0.7.0 J = rand(4,10,1…

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## [Force \`pkg\> develop xxx\` to clone latest commit](https://discourse.julialang.org/t/force-pkg-develop-xxx-to-clone-latest-commit/15907)

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**Author:** [@una-dinosauria](https://discourse.julialang.org/u/una-dinosauria)\
**Replies:** 7\
**Last updated:** [October 5, 2018, 3:42am UTC](https://discourse.julialang.org/t/force-pkg-develop-xxx-to-clone-latest-commit/15907 "2018-10-05T03:42:40Z")

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I am happily developing a package in my own machine, so I do (v1.0) pkg\> develop https://github.com/una-dinosauria/Rayuela.jl.git which, to my surprise, clones a commit from August 2018. How can I force develop to clo…

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## [Problems with Package instalations](https://discourse.julialang.org/t/problems-with-package-instalations/15906)

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**Author:** [@angeloaliano](https://discourse.julialang.org/u/angeloaliano)\
**Replies:** 1\
**Last updated:** [October 5, 2018, 3:00am UTC](https://discourse.julialang.org/t/problems-with-package-instalations/15906 "2018-10-05T03:00:31Z")

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I am a start user of Julia software. But, when I try to install the package, I have a problem, and a message appear. For example, I want to install the package Plots. I write Pkg.add(“Plots”) and apperar a error message…

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## [Using @debug in Atom console](https://discourse.julialang.org/t/using-debug-in-atom-console/15833)

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**Author:** [@cstook](https://discourse.julialang.org/u/cstook)\
**Replies:** 5\
**Last updated:** [October 4, 2018, 9:50pm UTC](https://discourse.julialang.org/t/using-debug-in-atom-console/15833 "2018-10-04T21:50:47Z")

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Including code vs. typing into console produces different behavior. Why? The file debug.jl contains the following code. using Base.CoreLogging: Debug, global\_logger using Logging: ConsoleLogger global\_logger(ConsoleLo…

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## [Moving from v0.6 to v1.0 has been so annoying](https://discourse.julialang.org/t/moving-from-v0-6-to-v1-0-has-been-so-annoying/15740)

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**Author:** [@masiddique](https://discourse.julialang.org/u/masiddique)\
**Replies:** 36\
**Last updated:** [October 4, 2018, 8:21pm UTC](https://discourse.julialang.org/t/moving-from-v0-6-to-v1-0-has-been-so-annoying/15740 "2018-10-04T20:21:01Z")

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I just wanted to share my experience in moving from v0.6.4 to 1.0. I have to say, it has been extremely annoying, and I am wondering why I choose to work in Julia. The developers should have in mind there are several peo…

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## [Making high performance functions with flexible inputs](https://discourse.julialang.org/t/making-high-performance-functions-with-flexible-inputs/15890)

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**Author:** [@joshdorrington](https://discourse.julialang.org/u/joshdorrington)\
**Replies:** 1\
**Last updated:** [October 4, 2018, 7:28pm UTC](https://discourse.julialang.org/t/making-high-performance-functions-with-flexible-inputs/15890 "2018-10-04T19:28:10Z")

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I’m writing some code to solve a couple of o.d.e systems I’m working with. At the moment I have some code that looks like this: function timestep\_a(init;T=1.,dt=0.0005) for t in 0.:dt:T …

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## [@eval in loop error](https://discourse.julialang.org/t/eval-in-loop-error/15889)

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**Author:** [@programista](https://discourse.julialang.org/u/programista)\
**Replies:** 3\
**Last updated:** [October 4, 2018, 5:59pm UTC](https://discourse.julialang.org/t/eval-in-loop-error/15889 "2018-10-04T17:59:06Z")

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Julia 0.7 loop like below in row @eval($vx=findnz(cij)\[1\].+(i-1)\*skok) ERROR: UndefVarError: cij without loop (when i=j=1 tthis line working ! var cij is local var and exist What wrong ? for i=1:length(zakresy).-…

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## [Write DataFrame to SQLite table?](https://discourse.julialang.org/t/write-dataframe-to-sqlite-table/8319)

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**Author:** [@onetonfoot](https://discourse.julialang.org/u/onetonfoot)\
**Replies:** 6\
**Last updated:** [October 4, 2018, 5:30pm UTC](https://discourse.julialang.org/t/write-dataframe-to-sqlite-table/8319 "2018-10-04T17:30:30Z")

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I’m trying to figure out how to write a data frame to a sqlite3 table using SQLite.jl, but can’t wrap my head around the docs?

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## [Julia work with Notepad++?](https://discourse.julialang.org/t/julia-work-with-notepad/15884)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 0\
**Last updated:** [October 4, 2018, 2:58pm UTC](https://discourse.julialang.org/t/julia-work-with-notepad/15884 "2018-10-04T14:58:22Z")

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Has anyone managed to get basic Julia work (repl+eval) and code highlighting and such to work with Notepad++?

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