# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1806

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

**Page:** 1807

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## [Recursive call with ForwardDiff](https://discourse.julialang.org/t/recursive-call-with-forwarddiff/35678)

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**Author:** [@edljk](https://discourse.julialang.org/u/edljk)\
**Replies:** 0\
**Last updated:** [March 7, 2020, 8:34am UTC](https://discourse.julialang.org/t/recursive-call-with-forwarddiff/35678 "2020-03-07T08:34:05Z")

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Dear all, I considered the following piece of code. The Forward package is impressive in its flexibility! Nevertheless, I wonder if I am not missing some obvious optimization? Any suggestion are welcome. using ForwardD…

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## [Density-based clustering with incomplete distance matrix](https://discourse.julialang.org/t/density-based-clustering-with-incomplete-distance-matrix/35675)

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**Author:** [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)\
**Replies:** 0\
**Last updated:** [March 7, 2020, 4:12am UTC](https://discourse.julialang.org/t/density-based-clustering-with-incomplete-distance-matrix/35675 "2020-03-07T04:12:26Z")

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I am looking for a clustering algorithm (probably density based) that works with custom distances (I have my own non-Euclidean distance metric) and can work on very large datasets. I can evaluate nearest neighbors quickl…

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## [Julia breaks down](https://discourse.julialang.org/t/julia-breaks-down/35659)

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**Author:** [@Ksun46](https://discourse.julialang.org/u/Ksun46)\
**Replies:** 10\
**Last updated:** [March 7, 2020, 2:21am UTC](https://discourse.julialang.org/t/julia-breaks-down/35659 "2020-03-07T02:21:52Z")

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Hi all. I am using Julia through Juno on a Mac, and got the following error today when I was trying to call the optimize! function from JuMP using JuMP, Ipopt m\_test = Model(with\_optimizer(Ipopt.Optimizer, linear\_sol…

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## [SQLite.jl install error with Julia1.3.1](https://discourse.julialang.org/t/sqlite-jl-install-error-with-julia1-3-1/35007)

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**Author:** [@zhangliye](https://discourse.julialang.org/u/zhangliye)\
**Replies:** 10\
**Last updated:** [March 7, 2020, 2:16am UTC](https://discourse.julialang.org/t/sqlite-jl-install-error-with-julia1-3-1/35007 "2020-03-07T02:16:53Z")

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I got the following errors while installing SQLite.jl on Julia1.3.1. without error for the old version of Julia1.1. The followings are the error message. Resolving package versions... ERROR: Unable to automatically inst…

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## [MySQL.jl install error](https://discourse.julialang.org/t/mysql-jl-install-error/35277)

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**Author:** [@zhangliye](https://discourse.julialang.org/u/zhangliye)\
**Replies:** 11\
**Last updated:** [March 7, 2020, 2:14am UTC](https://discourse.julialang.org/t/mysql-jl-install-error/35277 "2020-03-07T02:14:20Z")

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I got the following error while installing MySQL.jl on windows 10. (@v1.3) pkg\> add MySQL Updating registry at \`C:\\Users\\zhangly\\.juliapro\\JuliaPro\_v1.3.1-1\\registries\\JuliaPro\` tar: Can't convert a path to a wchar\_t…

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## [Vararg vs Tuple{Vararg} performance](https://discourse.julialang.org/t/vararg-vs-tuple-vararg-performance/35670)

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**Author:** [@SnoopyDoowop](https://discourse.julialang.org/u/SnoopyDoowop)\
**Replies:** 4\
**Last updated:** [March 7, 2020, 12:30am UTC](https://discourse.julialang.org/t/vararg-vs-tuple-vararg-performance/35670 "2020-03-07T00:30:09Z")

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Hello! While trying out some things in the julia REPL to see how a\[i…\] = x is transformed into setindex!(a, x, i…). I came across multiple questions : I am wondering why the prototype of setindex! is setindex!(A::Abstr…

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## [Going from python to Julia](https://discourse.julialang.org/t/going-from-python-to-julia/35664)

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**Author:** [@evcon131](https://discourse.julialang.org/u/evcon131)\
**Replies:** 5\
**Last updated:** [March 6, 2020, 11:00pm UTC](https://discourse.julialang.org/t/going-from-python-to-julia/35664 "2020-03-06T23:00:39Z")

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I really want to learn Julia to replace what I do in python. I was trying to create some basic things and kept getting errors I couldn’t resolve. This is an example of what I do in python: cd={} opt='' oldtime=time.time…

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## [Working with MulAddMul](https://discourse.julialang.org/t/working-with-muladdmul/35668)

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**Author:** [@bjack205](https://discourse.julialang.org/u/bjack205)\
**Replies:** 0\
**Last updated:** [March 6, 2020, 10:34pm UTC](https://discourse.julialang.org/t/working-with-muladdmul/35668 "2020-03-06T22:34:51Z")

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I’m trying to implement the 5-argument mul! made available in Julia v1.3 on StaticArrays, and SizedArrays in particular. I’m trying to make use of LinearAlgebra.MulAddMul that is used throughout the matrix multiplication…

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## [Trying to use Measurement.jl with DifferentialEquations.jl](https://discourse.julialang.org/t/trying-to-use-measurement-jl-with-differentialequations-jl/35655)

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**Author:** [@Hossein\_Haghi](https://discourse.julialang.org/u/Hossein_Haghi)\
**Replies:** 11\
**Last updated:** [March 6, 2020, 10:14pm UTC](https://discourse.julialang.org/t/trying-to-use-measurement-jl-with-differentialequations-jl/35655 "2020-03-06T22:14:23Z")

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In the example below I am trying to use Measurement.jl with DiffernetialEquations.jl to solve an ODE with error propagation. clearconsole() @time using DifferentialEquations, Measurements, MATLAB function Buckle(du,u,…

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## [Parellel arrays](https://discourse.julialang.org/t/parellel-arrays/35645)

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**Author:** [@eaubanel](https://discourse.julialang.org/u/eaubanel)\
**Replies:** 4\
**Last updated:** [March 6, 2020, 8:33pm UTC](https://discourse.julialang.org/t/parellel-arrays/35645 "2020-03-06T20:33:43Z")

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I need to have multiple threads write values to a shared array. I’m thinking of having each thread write to a private array, and then have the threads each write their private values into a shared array. In the following…

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## [Julia breaks down when using JuMP through Atom](https://discourse.julialang.org/t/julia-breaks-down-when-using-jump-through-atom/35658)

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**Author:** [@Ksun46](https://discourse.julialang.org/u/Ksun46)\
**Replies:** 1\
**Last updated:** [March 6, 2020, 7:51pm UTC](https://discourse.julialang.org/t/julia-breaks-down-when-using-jump-through-atom/35658 "2020-03-06T19:51:41Z")

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Hi all, I am using Julia through Juno/Atom on a Mac, and got the following error today I can run my code through the terminal through. I am not sure what’s going on here. Any suggestions? Thanks.

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## [\`Serialization.serialize()\` strings are not interned, causing duplication](https://discourse.julialang.org/t/serialization-serialize-strings-are-not-interned-causing-duplication/35626)

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**Author:** [@NHDaly](https://discourse.julialang.org/u/NHDaly)\
**Replies:** 0\
**Last updated:** [March 6, 2020, 5:11am UTC](https://discourse.julialang.org/t/serialization-serialize-strings-are-not-interned-causing-duplication/35626 "2020-03-06T05:11:09Z")

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Can anyone help me understand the serialization behavior for many shared references to large strings? I’ve noticed that multiple shared references to strings end up duplicated on disk when serialized via Serialization.se…

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## [Problems reading compressed HDF5 file created in Python](https://discourse.julialang.org/t/problems-reading-compressed-hdf5-file-created-in-python/35580)

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**Author:** [@adriano.vilela](https://discourse.julialang.org/u/adriano.vilela)\
**Replies:** 6\
**Last updated:** [March 6, 2020, 6:04pm UTC](https://discourse.julialang.org/t/problems-reading-compressed-hdf5-file-created-in-python/35580 "2020-03-06T18:04:24Z")

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I’m having problems reading an HDF5 file that was saved in Python with the pytables library (www.pytables.org). The file I’m trying to read is available at: https://www.cefala.org/~adriano/.shared/simple\_mjpeg\_frames\_0\_…

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## [User-Defined Struct Constructors similar to Named Tuples](https://discourse.julialang.org/t/user-defined-struct-constructors-similar-to-named-tuples/35596)

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**Author:** [@Deduction42](https://discourse.julialang.org/u/Deduction42)\
**Replies:** 3\
**Last updated:** [March 6, 2020, 6:08pm UTC](https://discourse.julialang.org/t/user-defined-struct-constructors-similar-to-named-tuples/35596 "2020-03-06T18:08:03Z")

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When initializing user-define objects or structs, I find that he positional argument approach isn’t very clean. For example, let us say that we first start with mutable struct MyPoint x::Float64 z::Float64 end Then …

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## [Generalized eigenvalues with Diagonal B](https://discourse.julialang.org/t/generalized-eigenvalues-with-diagonal-b/35372)

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**Author:** [@tobydriscoll](https://discourse.julialang.org/u/tobydriscoll)\
**Replies:** 4\
**Last updated:** [March 6, 2020, 5:45pm UTC](https://discourse.julialang.org/t/generalized-eigenvalues-with-diagonal-b/35372 "2020-03-06T17:45:13Z")

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Looking to solve a generalized eigenproblem. All is well here: julia\> A = rand(4,4); julia\> B = rand(4,4); julia\> eigen(A,B) GeneralizedEigen{Complex{Float64},Complex{Float64},Array{Complex{Float64},2},Array{Complex{Flo…

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## [Create view for an Array of FieldVector](https://discourse.julialang.org/t/create-view-for-an-array-of-fieldvector/35649)

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**Author:** [@CFBaptista](https://discourse.julialang.org/u/CFBaptista)\
**Replies:** 4\
**Last updated:** [March 6, 2020, 5:14pm UTC](https://discourse.julialang.org/t/create-view-for-an-array-of-fieldvector/35649 "2020-03-06T17:14:21Z")

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Let’s say I have a struct that represents a point in 3D: using StaticArrays struct Point3D{T} \<: FieldVector{3, T} x::T y::T z::T end Then I generate some points like: points = rand(Point3D{Float64}, 10) I…

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## [How store this variable into files, and reaload it?](https://discourse.julialang.org/t/how-store-this-variable-into-files-and-reaload-it/35636)

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**Author:** [@Darione](https://discourse.julialang.org/u/Darione)\
**Replies:** 7\
**Last updated:** [March 6, 2020, 4:55pm UTC](https://discourse.julialang.org/t/how-store-this-variable-into-files-and-reaload-it/35636 "2020-03-06T16:55:30Z")

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Hello, I have this two kind of variabiles, x and y, to save to file, and after to reload. julia\> x Dict{Any,Any} with 2 entries: "day" =\> \[1, 2, 3\] "beautifull" =\> \[7, 5, 10, 11, 23, 56\] julia\> y = \[\["W…

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## [Vecnorm Error](https://discourse.julialang.org/t/vecnorm-error/35648)

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**Author:** [@JP\_Nieto](https://discourse.julialang.org/u/JP_Nieto)\
**Replies:** 1\
**Last updated:** [March 6, 2020, 4:26pm UTC](https://discourse.julialang.org/t/vecnorm-error/35648 "2020-03-06T16:26:14Z")

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I have this code that must be from an old version function column\_norms(X, i) M = size(X)\[2\] X\_diff = X .- X\[:, i\] norm\_vector = \[vecnorm(X\_diff\[:, k\]) for k=1:M\] norm\_vector\[i\] = 10^10 return(norm\_vector) ERROR: …

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## [Vegalite.jl: levels and DataFrames](https://discourse.julialang.org/t/vegalite-jl-levels-and-dataframes/35638)

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**Author:** [@Usor](https://discourse.julialang.org/u/Usor)\
**Replies:** 10\
**Last updated:** [March 6, 2020, 4:15pm UTC](https://discourse.julialang.org/t/vegalite-jl-levels-and-dataframes/35638 "2020-03-06T16:15:18Z")

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I was reading about levels for DataFrames. How exactly can they be useful with Vegalite.jl? I read about for example display purposes: when I tried to plot some data with this in mind (already some months ago), there wa…

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## [Batteries included](https://discourse.julialang.org/t/batteries-included/35565)

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**Author:** [@Darione](https://discourse.julialang.org/u/Darione)\
**Replies:** 19\
**Last updated:** [March 6, 2020, 4:13pm UTC](https://discourse.julialang.org/t/batteries-included/35565 "2020-03-06T16:13:35Z")

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While I got stuck importing a package to save arrays to text files, I’m thinking that Julia doesn’t appear too “batteries included”, as are Python and PHP for example. How come this difference in setting? Is it because…

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## [Predicting discrete events == expenses](https://discourse.julialang.org/t/predicting-discrete-events-expenses/35612)

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**Author:** [@yakir12](https://discourse.julialang.org/u/yakir12)\
**Replies:** 12\
**Last updated:** [March 6, 2020, 4:02pm UTC](https://discourse.julialang.org/t/predicting-discrete-events-expenses/35612 "2020-03-06T16:02:48Z")

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This question is 50% not about Julia. When I try to predict how much money I will spend in the future, I sum expenses per month for multiple months and base my stats on that set of monthly expenses. But, it feels like I…

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## [Register and specialize a function in a different module/package (Julia segfaults)](https://discourse.julialang.org/t/register-and-specialize-a-function-in-a-different-module-package-julia-segfaults/35591)

<div class="topic-metadata">

**Author:** [@essenciary](https://discourse.julialang.org/u/essenciary)\
**Replies:** 12\
**Last updated:** [March 6, 2020, 3:33pm UTC](https://discourse.julialang.org/t/register-and-specialize-a-function-in-a-different-module-package-julia-segfaults/35591 "2020-03-06T15:33:27Z")

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I am working on a DSL for creating web pages. Something like this (Julia like pseudo-code): module Html function table(f::Function; args...) # actual implementation here end function tr(f::Function; args...) # actual …

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## [Access to the Julia Zulip chats](https://discourse.julialang.org/t/access-to-the-julia-zulip-chats/35610)

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**Author:** [@Mason](https://discourse.julialang.org/u/Mason)\
**Replies:** 9\
**Last updated:** [March 6, 2020, 3:28pm UTC](https://discourse.julialang.org/t/access-to-the-julia-zulip-chats/35610 "2020-03-06T15:28:36Z")

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Hi all, as some may know, a lot of us are experimenting with using Zulip instead of Slack right now but we’ve noticed that julialang.zulipchat.com and julia.zulipchat.com both already exist but we haven’t been able to fi…

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## [Varinfo() slow if variable large](https://discourse.julialang.org/t/varinfo-slow-if-variable-large/35585)

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**Author:** [@Usor](https://discourse.julialang.org/u/Usor)\
**Replies:** 4\
**Last updated:** [March 6, 2020, 2:02pm UTC](https://discourse.julialang.org/t/varinfo-slow-if-variable-large/35585 "2020-03-06T14:02:36Z")

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I’ve often had not-so-large DataFrames loaded, and performance with varinfo() was good. When a DataFrame exceeds a certain size, e.g. beyond 100 MB, varinfo() is very slow. (I didn’t check the exact size, but the one lo…

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## [How to only read (first or last better) element of Set?](https://discourse.julialang.org/t/how-to-only-read-first-or-last-better-element-of-set/35635)

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**Author:** [@programista](https://discourse.julialang.org/u/programista)\
**Replies:** 7\
**Last updated:** [March 6, 2020, 1:49pm UTC](https://discourse.julialang.org/t/how-to-only-read-first-or-last-better-element-of-set/35635 "2020-03-06T13:49:53Z")

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How to only read (first or last better) element of Set ? julia\> X=Set(\["a","b"\]) Set(\["b", "a"\]) julia\> X\[1\] ERROR: MethodError: no method matching getindex(::Set{String}, ::Int64) Stacktrace: \[1\] top-level scope at n…

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## [Storing evaled function inside a struct](https://discourse.julialang.org/t/storing-evaled-function-inside-a-struct/35454)

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**Author:** [@Karajan](https://discourse.julialang.org/u/Karajan)\
**Replies:** 28\
**Last updated:** [March 6, 2020, 1:30pm UTC](https://discourse.julialang.org/t/storing-evaled-function-inside-a-struct/35454 "2020-03-06T13:30:50Z")

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Hi everyone! I’m looking for feedback on the approach of some code I’ve written. Since the code is for work I’ll share a greatly simplified version of what it looks like. I’d like to hear opinions on the “right way” to…

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## [How to get the full output from python using PyCall](https://discourse.julialang.org/t/how-to-get-the-full-output-from-python-using-pycall/35634)

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**Author:** [@zwwi](https://discourse.julialang.org/u/zwwi)\
**Replies:** 4\
**Last updated:** [March 6, 2020, 12:59pm UTC](https://discourse.julialang.org/t/how-to-get-the-full-output-from-python-using-pycall/35634 "2020-03-06T12:59:04Z")

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Hello, I’m trying to use the iminuit package from python. However, I do not know whether it is possible to get all the output from python. Here is some simple code in python: from iminuit import Minuit def f(a, b): …

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## [PyPlot add vertical line](https://discourse.julialang.org/t/pyplot-add-vertical-line/35632)

<div class="topic-metadata">

**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 2\
**Last updated:** [March 6, 2020, 12:42pm UTC](https://discourse.julialang.org/t/pyplot-add-vertical-line/35632 "2020-03-06T12:42:39Z")

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Hello, I would like to add 1. a single vertical line and 2. a series of vertical lines to a PyPlot chart. I have, let’s say, an x value of 38, how do I plot a vertical line on that point? And if I create a vector with…

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## [AWS avoid loading to memory when putting](https://discourse.julialang.org/t/aws-avoid-loading-to-memory-when-putting/35637)

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**Author:** [@yakir12](https://discourse.julialang.org/u/yakir12)\
**Replies:** 0\
**Last updated:** [March 6, 2020, 12:44pm UTC](https://discourse.julialang.org/t/aws-avoid-loading-to-memory-when-putting/35637 "2020-03-06T12:44:40Z")

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I’m recording videos from a raspberry pi and want to put those on an S3 bucket using AWSS3.jl. The thing is, these videos can be large approaching the RAM of the RPI (in my case 2GB). So I’s like to avoid loading them to…

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## [MKL.jl + Python](https://discourse.julialang.org/t/mkl-jl-python/35631)

<div class="topic-metadata">

**Author:** [@fgerick](https://discourse.julialang.org/u/fgerick)\
**Replies:** 2\
**Last updated:** [March 6, 2020, 10:37am UTC](https://discourse.julialang.org/t/mkl-jl-python/35631 "2020-03-06T10:37:25Z")

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Hi, is there a way of building MKL.jl such that it uses the MKL library of the (anaconda) Python that PyCall.jl is linked to? The reason is the issue arising when two different builds of MKL are combined: PyPlot conflict…

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