# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1733

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

**Page:** 1734

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## [Circle surface](https://discourse.julialang.org/t/circle-surface/40094)

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**Author:** [@Venom](https://discourse.julialang.org/u/Venom)\
**Replies:** 4\
**Last updated:** [May 30, 2020, 2:13am UTC](https://discourse.julialang.org/t/circle-surface/40094 "2020-05-30T02:13:08Z")

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Hi, I make first steps in Julia and I want to do circle surface. I can only makes surface on rectangles field in 3D. I will be really thankfull for tips. I attach photo, what it should look like

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## [Is the way, how to get array of value from the Dict by array of keys?](https://discourse.julialang.org/t/is-the-way-how-to-get-array-of-value-from-the-dict-by-array-of-keys/40436)

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**Author:** [@BMval](https://discourse.julialang.org/u/BMval)\
**Replies:** 2\
**Last updated:** [May 30, 2020, 1:34am UTC](https://discourse.julialang.org/t/is-the-way-how-to-get-array-of-value-from-the-dict-by-array-of-keys/40436 "2020-05-30T01:34:26Z")

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Is the way, how to get an array of values from the Dict by array of keys? the same way as DataFrames works. For instance. a=Dict(1=\>"a",2="b",3=\>"c") a\[\[1,2\]\] gets \["a","b"\] thank you in advance.

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## [Julia New York Virtual Coffee Shop](https://discourse.julialang.org/t/julia-new-york-virtual-coffee-shop/40154)

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**Author:** [@JeffreySarnoff](https://discourse.julialang.org/u/JeffreySarnoff)\
**Replies:** 2\
**Last updated:** [May 30, 2020, 12:56am UTC](https://discourse.julialang.org/t/julia-new-york-virtual-coffee-shop/40154 "2020-05-30T00:56:54Z")

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Topic: Julia New York Virtual Coffee Shop Time: May 26, 2020 05:30 PM Eastern Time (US and Canada) (21:30 UTC) Join Zoom Meeting Meeting ID: 893 7558 5776

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## [Call for Community supplied Julia Academy courses](https://discourse.julialang.org/t/call-for-community-supplied-julia-academy-courses/40447)

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**Author:** [@logankilpatrick](https://discourse.julialang.org/u/logankilpatrick)\
**Replies:** 0\
**Last updated:** [May 30, 2020, 12:52am UTC](https://discourse.julialang.org/t/call-for-community-supplied-julia-academy-courses/40447 "2020-05-30T00:52:52Z")

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Hey all! We are still looking for additional materials to turn into courses for JuliaAcademy.com. In case you aren’t familiar, JuliaAcademy is a free and open source set of videos and notebooks designed to be the on ram…

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## [Optimization with cost and constraints returned from a single function call](https://discourse.julialang.org/t/optimization-with-cost-and-constraints-returned-from-a-single-function-call/40433)

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**Author:** [@DrPapa](https://discourse.julialang.org/u/DrPapa)\
**Replies:** 4\
**Last updated:** [May 29, 2020, 11:28pm UTC](https://discourse.julialang.org/t/optimization-with-cost-and-constraints-returned-from-a-single-function-call/40433 "2020-05-29T23:28:55Z")

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I need to solve a constrained non-linear optimization problem where the cost and constraints are computed via a vector-value function. E.g., instead of J = cost(x) c1 = constraint1(x) c2 = constraint2(x) I have, for ef…

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## [Julia precompile](https://discourse.julialang.org/t/julia-precompile/34282)

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**Author:** [@raqkaaq](https://discourse.julialang.org/u/raqkaaq)\
**Replies:** 4\
**Last updated:** [May 29, 2020, 11:24pm UTC](https://discourse.julialang.org/t/julia-precompile/34282 "2020-05-29T23:24:58Z")

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I am completely new to julia, and I would like to learn how to optimize my code to run as fast as possible. I don’t know if this has already been answered or not, but I created a .julia/config/startup.jl file with the li…

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## [Jupyterlab or nteract borks on vegalite plot, bug or something I'm doing wrong?](https://discourse.julialang.org/t/jupyterlab-or-nteract-borks-on-vegalite-plot-bug-or-something-im-doing-wrong/40443)

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**Author:** [@dlakelan](https://discourse.julialang.org/u/dlakelan)\
**Replies:** 0\
**Last updated:** [May 29, 2020, 10:33pm UTC](https://discourse.julialang.org/t/jupyterlab-or-nteract-borks-on-vegalite-plot-bug-or-something-im-doing-wrong/40443 "2020-05-29T22:33:54Z")

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I’m trying out the simplest example I could think of in Jupyterlab and it borked… Is there something that I need to do to get vegalite plots to show up properly? (NOTE: it also borks in nteract) If I do this from the RE…

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## [CUDAnative out of resources, but only when run from Atom/Juno?](https://discourse.julialang.org/t/cudanative-out-of-resources-but-only-when-run-from-atom-juno/40428)

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**Author:** [@Alex\_Ellison](https://discourse.julialang.org/u/Alex_Ellison)\
**Replies:** 2\
**Last updated:** [May 29, 2020, 10:20pm UTC](https://discourse.julialang.org/t/cudanative-out-of-resources-but-only-when-run-from-atom-juno/40428 "2020-05-29T22:20:16Z")

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Hey GPU Gang, I have a kernel I’m trying to execute with CUDAnative. I’ve tested it with Nvidia Visual Profiler and it uses 46 registers/thread, and I can achieve the theoretical max of 1024 threads/block when I run it …

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## [Estimating a Multivariate Distribution](https://discourse.julialang.org/t/estimating-a-multivariate-distribution/40375)

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**Author:** [@Ian\_Slagle](https://discourse.julialang.org/u/Ian_Slagle)\
**Replies:** 6\
**Last updated:** [May 29, 2020, 10:03pm UTC](https://discourse.julialang.org/t/estimating-a-multivariate-distribution/40375 "2020-05-29T22:03:45Z")

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Is there a package that can estimate a multivariate distribution? The input to this estimation isn’t really set in stone right now, but preferably it’s something that Optim.jl could work with. I essentially want somethin…

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## [Avoid GC freeing Ptr{Nothing}](https://discourse.julialang.org/t/avoid-gc-freeing-ptr-nothing/38664)

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**Author:** [@lobingera](https://discourse.julialang.org/u/lobingera)\
**Replies:** 25\
**Last updated:** [May 29, 2020, 9:34pm UTC](https://discourse.julialang.org/t/avoid-gc-freeing-ptr-nothing/38664 "2020-05-29T21:34:28Z")

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I’m using (as interface between C-APIs) a mutable struct InterpreterHooks closure::Ptr{Nothing} surface\_create::Ptr{Nothing} surface\_destroy::Ptr{Nothing} context\_create::Ptr{Nothing} context\_destroy::Ptr{Nothi…

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## [How to round down coefficients in a constraint in Julia/JuMP?](https://discourse.julialang.org/t/how-to-round-down-coefficients-in-a-constraint-in-julia-jump/29381)

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**Author:** [@Shor](https://discourse.julialang.org/u/Shor)\
**Replies:** 15\
**Last updated:** [May 29, 2020, 8:50pm UTC](https://discourse.julialang.org/t/how-to-round-down-coefficients-in-a-constraint-in-julia-jump/29381 "2020-05-29T20:50:31Z")

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Hi, I am new here. I don’t know how to round down coefficients in my constraints. (only coefficients in this constraint. I don’t want to round down elements in the given array) Anyone can help me? Thanks in advance!

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## [Link axes in Plots.jl](https://discourse.julialang.org/t/link-axes-in-plots-jl/40426)

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**Author:** [@feanor12](https://discourse.julialang.org/u/feanor12)\
**Replies:** 2\
**Last updated:** [May 29, 2020, 8:46pm UTC](https://discourse.julialang.org/t/link-axes-in-plots-jl/40426 "2020-05-29T20:46:55Z")

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I want to plot the projections of a 2d map on the right and below the 2d plot, but if I show the colorbar the axis are not aligned anymore. How can I align the axes? Is there a way to place the colorbar in the bottom r…

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## [Open vscode plot pane in 2nd editor group](https://discourse.julialang.org/t/open-vscode-plot-pane-in-2nd-editor-group/40403)

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**Author:** [@heliosdrm](https://discourse.julialang.org/u/heliosdrm)\
**Replies:** 2\
**Last updated:** [May 29, 2020, 8:26pm UTC](https://discourse.julialang.org/t/open-vscode-plot-pane-in-2nd-editor-group/40403 "2020-05-29T20:26:54Z")

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I like how Juno allows to configure the layout, such that the plot pane (and others) start always at the same place. In VS Code, when I make the first plot, the plot viewer is opened as a new tab in the editor group I’…

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## [Understanding nested Threads.@threads scheduling](https://discourse.julialang.org/t/understanding-nested-threads-threads-scheduling/40400)

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**Author:** [@jw3126](https://discourse.julialang.org/u/jw3126)\
**Replies:** 4\
**Last updated:** [May 29, 2020, 6:05pm UTC](https://discourse.julialang.org/t/understanding-nested-threads-threads-scheduling/40400 "2020-05-29T18:05:38Z")

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When I nest Threads.@threads loops, scheduling looks strange: using Base.Threads using Dates function tmap(f, arr) out = similar(arr, Any) Threads.@threads for i in eachindex(arr) out\[i\] = f(arr\[i\]) …

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## [One-dimensional Array access](https://discourse.julialang.org/t/one-dimensional-array-access/40427)

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**Author:** [@erlebach](https://discourse.julialang.org/u/erlebach)\
**Replies:** 9\
**Last updated:** [May 29, 2020, 5:50pm UTC](https://discourse.julialang.org/t/one-dimensional-array-access/40427 "2020-05-29T17:50:22Z")

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I have an array: a = collect(1:20) and I wish to access elements 1:10 and 14. How is that done? In python, with Numpy, I could do a\[1:10,14\]. Is there an accepted approach in Julia. Everything I tried has failed. I am…

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## [Problem with a hypergeometric Turing model](https://discourse.julialang.org/t/problem-with-a-hypergeometric-turing-model/40425)

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**Author:** [@mlanghinrichs](https://discourse.julialang.org/u/mlanghinrichs)\
**Replies:** 9\
**Last updated:** [May 29, 2020, 5:50pm UTC](https://discourse.julialang.org/t/problem-with-a-hypergeometric-turing-model/40425 "2020-05-29T17:50:12Z")

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Hi all, I’m trying to get a bit more into probabilistic programming with Turing.jl. I want to build a simple hypergeometric model. Imagine you have a large box with Nred red and Nblue blue balls (makes N = Nred + Nblue …

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## [Pipeline writes out of order](https://discourse.julialang.org/t/pipeline-writes-out-of-order/40351)

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**Author:** [@sijo](https://discourse.julialang.org/u/sijo)\
**Replies:** 10\
**Last updated:** [May 29, 2020, 4:23pm UTC](https://discourse.julialang.org/t/pipeline-writes-out-of-order/40351 "2020-05-29T16:23:17Z")

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Is the following a bug or am I doing something wrong? julia\> open("test.txt", "w") do file write(file, "line1\\n") run(pipeline(\`echo line2\`, file)) write(file, "line3\\n") end; sh…

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## [Profiling doesn't count matrix products correctly](https://discourse.julialang.org/t/profiling-doesnt-count-matrix-products-correctly/40420)

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**Author:** [@mhauru](https://discourse.julialang.org/u/mhauru)\
**Replies:** 1\
**Last updated:** [May 29, 2020, 3:52pm UTC](https://discourse.julialang.org/t/profiling-doesnt-count-matrix-products-correctly/40420 "2020-05-29T15:52:17Z")

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Here’s a function that should spend exactly half of its time doing a matrix product, the other half sleeping: function f(A, B) starttime = time() C = A\*B # C = sort(A\[:\]) # C = svd(A) endtime = time(…

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## [Finding saddle point](https://discourse.julialang.org/t/finding-saddle-point/21168)

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**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 36\
**Last updated:** [May 29, 2020, 3:35pm UTC](https://discourse.julialang.org/t/finding-saddle-point/21168 "2020-05-29T15:35:51Z")

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I’m trying to find the saddle point of a function. I’ve programmed a function saddle below (but if you know of a library to find saddle points, please let me know). The idea is that the input function should be specified…

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## [How to serve a PlotlyJS.jl plot using Mux?](https://discourse.julialang.org/t/how-to-serve-a-plotlyjs-jl-plot-using-mux/40422)

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**Author:** [@robsmith11](https://discourse.julialang.org/u/robsmith11)\
**Replies:** 0\
**Last updated:** [May 29, 2020, 3:32pm UTC](https://discourse.julialang.org/t/how-to-serve-a-plotlyjs-jl-plot-using-mux/40422 "2020-05-29T15:32:36Z")

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I run Julia on a remote server, so I’d like to use my browser to view plots rather than Blink.jl. I filed an issue for PlotlyJS.jl because I think a simple example of what should be a common use-case would be a valuable…

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## [What crazy instability is this?](https://discourse.julialang.org/t/what-crazy-instability-is-this/40340)

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**Author:** [@joa-quim](https://discourse.julialang.org/u/joa-quim)\
**Replies:** 20\
**Last updated:** [May 29, 2020, 2:50pm UTC](https://discourse.julialang.org/t/what-crazy-instability-is-this/40340 "2020-05-29T14:50:35Z")

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The MWE function img16to8(mat::Array{UInt16}; kw...) d = Dict{Symbol,Any}(kw) img = Array{UInt8}(undef,size(mat)); if (haskey(d, :histo\_bounds)) val\_ = d\[:histo\_bounds\] val = UInt16.(val\_) # Th…

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## [\[DataFrames Question\]: Inner join DataFrame Array?](https://discourse.julialang.org/t/dataframes-question-inner-join-dataframe-array/40412)

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**Author:** [@Xijiang\_Yu](https://discourse.julialang.org/u/Xijiang_Yu)\
**Replies:** 4\
**Last updated:** [May 29, 2020, 2:24pm UTC](https://discourse.julialang.org/t/dataframes-question-inner-join-dataframe-array/40412 "2020-05-29T14:24:46Z")

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Question: Suppose I have an array of DataFrame t\[1:10\]. What is the neatest way to join them? innerjoin(t\[1\], t\[2\], ..., on = :tag, ...) # or df = t\[1\] for i in 2:10 df = innerjoin(df, t\[i\], on =...) end

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## [Is it "dangerous" to extend base methods for tuples?](https://discourse.julialang.org/t/is-it-dangerous-to-extend-base-methods-for-tuples/40398)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 7\
**Last updated:** [May 29, 2020, 2:15pm UTC](https://discourse.julialang.org/t/is-it-dangerous-to-extend-base-methods-for-tuples/40398 "2020-05-29T14:15:10Z")

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I have to work on a structure (a gradient of multiple layers) that I represent as a vector of tuples of Float/Arrays, where the different tuples in the array may have different structure, e.g. a = \[(\[1.0 2.0; 3.0 4.0\], …

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## [How to structure a mid-sized OOP-like project physically and logically - Types.jl, Submodules or "deep Hierarchies"?](https://discourse.julialang.org/t/how-to-structure-a-mid-sized-oop-like-project-physically-and-logically-types-jl-submodules-or-deep-hierarchies/40410)

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**Author:** [@PeterKeffer](https://discourse.julialang.org/u/PeterKeffer)\
**Replies:** 3\
**Last updated:** [May 29, 2020, 2:00pm UTC](https://discourse.julialang.org/t/how-to-structure-a-mid-sized-oop-like-project-physically-and-logically-types-jl-submodules-or-deep-hierarchies/40410 "2020-05-29T14:00:59Z")

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Hey there Julians! I’m still a bloody beginner with Julia, but want to start with a medium size OOP-structured project. (I’m also a CS student, so I’m still learning how to engineer software the right way) I started wr…

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## [Adding Documentation to a GitHub Repository](https://discourse.julialang.org/t/adding-documentation-to-a-github-repository/40405)

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**Author:** [@grahamstark](https://discourse.julialang.org/u/grahamstark)\
**Replies:** 4\
**Last updated:** [May 29, 2020, 2:00pm UTC](https://discourse.julialang.org/t/adding-documentation-to-a-github-repository/40405 "2020-05-29T14:00:58Z")

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Good morning from a very sunny Glasgow, Scotland. I’m experimenting setting up a Julia package in GitHub, with code coverage and testing using Travis. I’ve been following Chris Rackauckas’ excellent video. The reposit…

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## [An idea for sustainable and professional open source management](https://discourse.julialang.org/t/an-idea-for-sustainable-and-professional-open-source-management/40228)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 40\
**Last updated:** [May 29, 2020, 1:07pm UTC](https://discourse.julialang.org/t/an-idea-for-sustainable-and-professional-open-source-management/40228 "2020-05-29T13:07:23Z")

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I want to raise an idea. Currently, a large proportion of Julia packages are maintained by volunteers. This is great because the community benefit from the free labour and love of volunteers. Still, the con is that volun…

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## [Diffeqpy, using ensembling](https://discourse.julialang.org/t/diffeqpy-using-ensembling/40411)

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**Author:** [@Abolfazl\_Ziaeemehr](https://discourse.julialang.org/u/Abolfazl_Ziaeemehr)\
**Replies:** 1\
**Last updated:** [May 29, 2020, 12:36pm UTC](https://discourse.julialang.org/t/diffeqpy-using-ensembling/40411 "2020-05-29T12:36:03Z")

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It is possible to use use ensembling in diffeqpy? here is my example code: import numpy as np import pylab as pl from time import time from sys import exit try: from diffeqpy import de from julia import Main e…

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## [Numerical integration from 0.0 to Inf](https://discourse.julialang.org/t/numerical-integration-from-0-0-to-inf/40379)

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**Author:** [@Olivier\_Merchiers](https://discourse.julialang.org/u/Olivier_Merchiers)\
**Replies:** 5\
**Last updated:** [May 29, 2020, 12:00pm UTC](https://discourse.julialang.org/t/numerical-integration-from-0-0-to-inf/40379 "2020-05-29T12:00:03Z")

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Hello everyone, I was playing around with QuadGK.jl on my function f(x) which has some strong oscillations but a finite value when integrating from 0 to \\infty. I used the transformation described in this link to solve…

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## [DocStringExtensions - interpolation string "$" allowed only in the preamble but not inside the structure](https://discourse.julialang.org/t/docstringextensions-interpolation-string-allowed-only-in-the-preamble-but-not-inside-the-structure/40349)

<div class="topic-metadata">

**Author:** [@yurier](https://discourse.julialang.org/u/yurier)\
**Replies:** 2\
**Last updated:** [May 29, 2020, 11:34am UTC](https://discourse.julialang.org/t/docstringextensions-interpolation-string-allowed-only-in-the-preamble-but-not-inside-the-structure/40349 "2020-05-29T11:34:39Z")

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I would like to pass a function to some docstrings inside a structure (by using $) not only in the preamble as in the example. works without $ inside the structure using Parameters, DocStringExtensions """ # My parame…

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## [ChisqTest parameter theta0 not recognized](https://discourse.julialang.org/t/chisqtest-parameter-theta0-not-recognized/40348)

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**Author:** [@leclere](https://discourse.julialang.org/u/leclere)\
**Replies:** 2\
**Last updated:** [May 29, 2020, 9:47am UTC](https://discourse.julialang.org/t/chisqtest-parameter-theta0-not-recognized/40348 "2020-05-29T09:47:42Z")

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I am trying to use the ChisqTest function to check adequation between my empirical repartition and a theoretical probability distribution. Unfortunately it seems that parameter theta0 is not recognized. MWE: ChisqTest(…

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