# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1631

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

**Page:** 1632

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## [Why doesn't Makie show pictures？](https://discourse.julialang.org/t/why-doesnt-makie-show-pictures/46571)

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**Author:** [@zlq178](https://discourse.julialang.org/u/zlq178)\
**Replies:** 3\
**Last updated:** [September 15, 2020, 9:03am UTC](https://discourse.julialang.org/t/why-doesnt-makie-show-pictures/46571 "2020-09-15T09:03:09Z")

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‘’’ using AbstractPlotting,Makie x = \[2 .\* (i/3) .\* cos(i) for i in range(0, stop = 4pi, length = 30)\] y = \[2 .\* (i/3) .\* sin(i) for i in range(0, stop = 4pi, length = 30)\] z = range(0, stop = 5, length = 30) a=mesh…

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## [There is nothing in html doc exported from Pluto notebook](https://discourse.julialang.org/t/there-is-nothing-in-html-doc-exported-from-pluto-notebook/46621)

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**Author:** [@Sijun](https://discourse.julialang.org/u/Sijun)\
**Replies:** 2\
**Last updated:** [September 15, 2020, 8:37am UTC](https://discourse.julialang.org/t/there-is-nothing-in-html-doc-exported-from-pluto-notebook/46621 "2020-09-15T08:37:25Z")

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Pluto is really a wonderful package; Overall look and feel of document is great, cells are very responsive while I edit, powerful @bind feature, etc. Now I want to export to html. But when I clicked on “export static …

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## [Performance of optimization problem in a loop](https://discourse.julialang.org/t/performance-of-optimization-problem-in-a-loop/46374)

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**Author:** [@Oliver\_Lylloff](https://discourse.julialang.org/u/Oliver_Lylloff)\
**Replies:** 14\
**Last updated:** [September 15, 2020, 7:30am UTC](https://discourse.julialang.org/t/performance-of-optimization-problem-in-a-loop/46374 "2020-09-15T07:30:37Z")

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Hello. I’m trying to improve the performance of an optimization problem. I have a Hermitian matrix and want to minimize the diagonal terms while keeping the matrix positive semidefinite. Given a matrix S, \\text{minimi…

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## [Unique rows indexes in array](https://discourse.julialang.org/t/unique-rows-indexes-in-array/46588)

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**Author:** [@programista](https://discourse.julialang.org/u/programista)\
**Replies:** 14\
**Last updated:** [September 15, 2020, 7:11am UTC](https://discourse.julialang.org/t/unique-rows-indexes-in-array/46588 "2020-09-15T07:11:46Z")

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julia\> baza2 45805×9 Array{String,2}: "0" "000001" "1" "1" "1" "000002" "" "0" "2" "000002" "" "0" julia\> ia = unique(i -\> baza2\[:,6\]\[i\], 1:length( baza2\[:,6\])) 40378-element Array{Int64,1}…

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## [Can't get right ranks when using non-blocking MPI.Irecv!()](https://discourse.julialang.org/t/cant-get-right-ranks-when-using-non-blocking-mpi-irecv/46361)

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**Author:** [@Ke\_Gao](https://discourse.julialang.org/u/Ke_Gao)\
**Replies:** 5\
**Last updated:** [September 15, 2020, 5:19am UTC](https://discourse.julialang.org/t/cant-get-right-ranks-when-using-non-blocking-mpi-irecv/46361 "2020-09-15T05:19:24Z")

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I am trying to let rank 0 get other rank indexes, but I got different results from MPI.Irecv!() and MPI.Recv() , and result from MPI.Irecv!() seems odd: import MPI function main() MPI.Init() comm = MPI.COMM\_WOR…

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## [Triple buffering](https://discourse.julialang.org/t/triple-buffering/46616)

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**Author:** [@cscherrer](https://discourse.julialang.org/u/cscherrer)\
**Replies:** 2\
**Last updated:** [September 15, 2020, 2:52am UTC](https://discourse.julialang.org/t/triple-buffering/46616 "2020-09-15T02:52:41Z")

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Hi, I’m curious if anyone has tried triple buffering. This is a generally useful framework, but I’m specifically thinking allocation-free MCMC (or maybe more accurately, iteration-independent allocation count). I think …

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## [\[ANN?\] Fzf (fuzzy search) for REPL history](https://discourse.julialang.org/t/ann-fzf-fuzzy-search-for-repl-history/42793)

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**Author:** [@jling](https://discourse.julialang.org/u/jling)\
**Replies:** 10\
**Last updated:** [September 15, 2020, 12:20am UTC](https://discourse.julialang.org/t/ann-fzf-fuzzy-search-for-repl-history/42793 "2020-09-15T00:20:03Z")

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By wrapping the fzf (fzf\_jll and JLFzf) (I realize it should probably just be called Fzf.jl but name is then too short (since potentially one can make a julia implementation of Fzf) now one can have a cool fuzzy search …

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## [Installing Julia System Wide](https://discourse.julialang.org/t/installing-julia-system-wide/46390)

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**Author:** [@anon60034542](https://discourse.julialang.org/u/anon60034542)\
**Replies:** 2\
**Last updated:** [September 14, 2020, 11:51pm UTC](https://discourse.julialang.org/t/installing-julia-system-wide/46390 "2020-09-14T23:51:21Z")

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I’m using Windows 10 on my desktop machine and I would like to install Julia system wide. When I follow the instructions to right click and run as administrator, it still wants to install it in my appdata folder (as if I…

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## [How do I publish documenter.jl-generated docs to a subdirectory of a custom subddomain?](https://discourse.julialang.org/t/how-do-i-publish-documenter-jl-generated-docs-to-a-subdirectory-of-a-custom-subddomain/46602)

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**Author:** [@vlandau](https://discourse.julialang.org/u/vlandau)\
**Replies:** 1\
**Last updated:** [September 14, 2020, 8:46pm UTC](https://discourse.julialang.org/t/how-do-i-publish-documenter-jl-generated-docs-to-a-subdirectory-of-a-custom-subddomain/46602 "2020-09-14T20:46:47Z")

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My github organization is hoping to serve docs for two Julia packages on a subdomain, docs.circuitscape.org. If you visit that page, you’ll see that currently it just shows the docs for one package, Omniscape.jl, but we …

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## [Passing strings from Matlab to Julia and back using Sockets](https://discourse.julialang.org/t/passing-strings-from-matlab-to-julia-and-back-using-sockets/46589)

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**Author:** [@Iulian.Cioarca](https://discourse.julialang.org/u/Iulian.Cioarca)\
**Replies:** 4\
**Last updated:** [September 14, 2020, 8:09pm UTC](https://discourse.julialang.org/t/passing-strings-from-matlab-to-julia-and-back-using-sockets/46589 "2020-09-14T20:09:02Z")

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I needed a simple communication channel between Matlab and Julia. Maybe this will help someone, so here’s the code (spoiler alert, everything is an ascii character): ## Matlab to Julia TCPIP communication example # Jul…

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## [Low-cost abstractions for C library wrappers](https://discourse.julialang.org/t/low-cost-abstractions-for-c-library-wrappers/46592)

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**Author:** [@serenity4](https://discourse.julialang.org/u/serenity4)\
**Replies:** 5\
**Last updated:** [September 14, 2020, 7:23pm UTC](https://discourse.julialang.org/t/low-cost-abstractions-for-c-library-wrappers/46592 "2020-09-14T19:23:48Z")

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Hi, As I am experimenting several ways to abstract over C libraries wrapped with Clang with minimal overhead, I am starting to wonder whether Julia is a good fit for this kind of thing if one wants to preserve performan…

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## [Getting off the ground with Gen](https://discourse.julialang.org/t/getting-off-the-ground-with-gen/44211)

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**Author:** [@terdmann](https://discourse.julialang.org/u/terdmann)\
**Replies:** 1\
**Last updated:** [September 14, 2020, 7:13pm UTC](https://discourse.julialang.org/t/getting-off-the-ground-with-gen/44211 "2020-09-14T19:13:48Z")

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I am really interested in Gen.jl, but am somewhat confused from the documentation. That is, I could not find any example of the functionality I’m trying to use. Can someone help me with the first steps? My first questio…

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## [Error when loading Queryverse: ParquetFiles \[46a..27f\] is required but does not seem to be installed](https://discourse.julialang.org/t/error-when-loading-queryverse-parquetfiles-46a-27f-is-required-but-does-not-seem-to-be-installed/46243)

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**Author:** [@birusod](https://discourse.julialang.org/u/birusod)\
**Replies:** 6\
**Last updated:** [September 14, 2020, 6:32pm UTC](https://discourse.julialang.org/t/error-when-loading-queryverse-parquetfiles-46a-27f-is-required-but-does-not-seem-to-be-installed/46243 "2020-09-14T18:32:50Z")

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I am trying to load Qeuryverse, but facing this issue. Here is the error: using Queryverse ┌ Info: Precompiling Queryverse \[612083be-0b0f-5412-89c1-4e7c75506a58\] └ @ Base loading.jl:1278 ERROR: LoadError: ArgumentErr…

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## [Numerical optimization function does not get cached](https://discourse.julialang.org/t/numerical-optimization-function-does-not-get-cached/46373)

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**Author:** [@xor0110](https://discourse.julialang.org/u/xor0110)\
**Replies:** 4\
**Last updated:** [September 14, 2020, 6:19pm UTC](https://discourse.julialang.org/t/numerical-optimization-function-does-not-get-cached/46373 "2020-09-14T18:19:06Z")

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I have an application with a number of image analysis functions based on LeastSquaresOptim.jl. The application has to be re-started often, unfortunately — maybe a topic for another post. Every time the application is ran…

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## [Calling a CUDA kernel in an external library](https://discourse.julialang.org/t/calling-a-cuda-kernel-in-an-external-library/46505)

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**Author:** [@Niclas\_Wiberg](https://discourse.julialang.org/u/Niclas_Wiberg)\
**Replies:** 6\
**Last updated:** [September 14, 2020, 5:48pm UTC](https://discourse.julialang.org/t/calling-a-cuda-kernel-in-an-external-library/46505 "2020-09-14T17:48:44Z")

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Is it possible to call a precompiled CUDA kernel from Julia? I am writing CUDA kernels in C++ and compiling with nvcc, for use in a C++ application. I use Julia to test the code. Currently I write host-side wrapping fun…

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## [Question about comprehensions](https://discourse.julialang.org/t/question-about-comprehensions/46595)

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**Author:** [@EmadMasroor](https://discourse.julialang.org/u/EmadMasroor)\
**Replies:** 6\
**Last updated:** [September 14, 2020, 5:22pm UTC](https://discourse.julialang.org/t/question-about-comprehensions/46595 "2020-09-14T17:22:45Z")

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I have found Julia’s comprehensions to be one of its most useful features, but I am running into a problem which I hope someone can help me out with. Let’s say I have an array of size N x 10 in a variable named data, wh…

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## [PackageCompiler uses no paralelism](https://discourse.julialang.org/t/packagecompiler-uses-no-paralelism/46590)

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**Author:** [@xor0110](https://discourse.julialang.org/u/xor0110)\
**Replies:** 1\
**Last updated:** [September 14, 2020, 3:22pm UTC](https://discourse.julialang.org/t/packagecompiler-uses-no-paralelism/46590 "2020-09-14T15:22:12Z")

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I’m finally learning to use PackageCompiler, things seem to be working great so far. I just noticed that at the “creating system image object file” step building an app for my project there seems to be no parallelism. I …

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## [LINQ inner joins and select all in Query.jl](https://discourse.julialang.org/t/linq-inner-joins-and-select-all-in-query-jl/46556)

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**Author:** [@mkarikom](https://discourse.julialang.org/u/mkarikom)\
**Replies:** 7\
**Last updated:** [September 14, 2020, 2:59pm UTC](https://discourse.julialang.org/t/linq-inner-joins-and-select-all-in-query-jl/46556 "2020-09-14T14:59:43Z")

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This MWE is supposed to do an inner join (i.a equals j.c || i.b equals j.e) and output all the elements of the first df: df1 = DataFrame(a=\[1,2,3\], b=\[1.,2.,3.\]) df2 = DataFrame(c=\[2,4,2\], d=\["John", "Jim","Sally"\],e=…

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## [Arrays of functions](https://discourse.julialang.org/t/arrays-of-functions/46549)

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**Author:** [@aerdely](https://discourse.julialang.org/u/aerdely)\
**Replies:** 19\
**Last updated:** [September 14, 2020, 2:34pm UTC](https://discourse.julialang.org/t/arrays-of-functions/46549 "2020-09-14T14:34:07Z")

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About the following code: f(x) = 2x + 1 g(x) = x^2 h(x) = x^3 I = \[f, g, h\] J = Array{Function, 2}(undef, 3, 3) for i ∈ 1:3 for j ∈ 1:3 J\[i, j\] = I\[i\] ∘ I\[j\] end end display(J) I get: 3×3 Array{Functi…

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## [Several packages won't precompile after update](https://discourse.julialang.org/t/several-packages-wont-precompile-after-update/46580)

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**Author:** [@Igor\_Douven](https://discourse.julialang.org/u/Igor_Douven)\
**Replies:** 1\
**Last updated:** [September 14, 2020, 12:44pm UTC](https://discourse.julialang.org/t/several-packages-wont-precompile-after-update/46580 "2020-09-14T12:44:23Z")

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Hi all, After I updated all packages this morning, several packages (e.g., Gadfly, Optim, KernelDensity) refuse to pre-compile, all giving the following error: LoadError: UndefVarError: @printf not defined I deleted t…

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## [Adjointing around Mutating Part](https://discourse.julialang.org/t/adjointing-around-mutating-part/46582)

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**Author:** [@rakeshvar](https://discourse.julialang.org/u/rakeshvar)\
**Replies:** 0\
**Last updated:** [September 14, 2020, 11:42am UTC](https://discourse.julialang.org/t/adjointing-around-mutating-part/46582 "2020-09-14T11:42:38Z")

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I have the following toy problem that imitates my more complex problem. (A follow up from this question.) function triangulate(x::Matrix{T}) where T m, n = size(x) a = x\[:,1\] .\* \[1; zeros(T, m-1)\] for i in 2…

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## [Recovering parameters from product of two truncated normal distributions](https://discourse.julialang.org/t/recovering-parameters-from-product-of-two-truncated-normal-distributions/46577)

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**Author:** [@Libbum](https://discourse.julialang.org/u/Libbum)\
**Replies:** 2\
**Last updated:** [September 14, 2020, 10:02am UTC](https://discourse.julialang.org/t/recovering-parameters-from-product-of-two-truncated-normal-distributions/46577 "2020-09-14T10:02:09Z")

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Hi all, I’ve been thrown into the deep end with some stats, and don’t know enough about the Julia ecosystem around my problem to know if I’m doing this right. For the moment, this is an example of what I’m doing: an in…

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## [Is slurpping typed keyword args invalid?](https://discourse.julialang.org/t/is-slurpping-typed-keyword-args-invalid/46568)

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**Author:** [@tk3369](https://discourse.julialang.org/u/tk3369)\
**Replies:** 3\
**Last updated:** [September 14, 2020, 7:32am UTC](https://discourse.julialang.org/t/is-slurpping-typed-keyword-args-invalid/46568 "2020-09-14T07:32:39Z")

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Slurrping keyword args is a fairly common usage: julia\> foo(; x...) = 1 foo (generic function with 1 method) julia\> foo() 1 But, if I annotate with type, then this function becomes non-callable… julia\> bar(; x::Int..…

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## [DiffEqParamEstim TypeAssert problem with forward AD](https://discourse.julialang.org/t/diffeqparamestim-typeassert-problem-with-forward-ad/46553)

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**Author:** [@moesphere](https://discourse.julialang.org/u/moesphere)\
**Replies:** 3\
**Last updated:** [September 14, 2020, 7:08am UTC](https://discourse.julialang.org/t/diffeqparamestim-typeassert-problem-with-forward-ad/46553 "2020-09-14T07:08:00Z")

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I am getting a typeassert problem when I use the build\_objective\_function in combination with forward AD. Optimization is via Optim. It works if I use finite differencing or e.g. Tsit5() instead of Rosenbrock23() as the …

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## [Using Threads@threads loop with my own rng](https://discourse.julialang.org/t/using-threads-threads-loop-with-my-own-rng/46567)

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**Author:** [@MFairley](https://discourse.julialang.org/u/MFairley)\
**Replies:** 1\
**Last updated:** [September 14, 2020, 4:06am UTC](https://discourse.julialang.org/t/using-threads-threads-loop-with-my-own-rng/46567 "2020-09-14T04:06:10Z")

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How do I create and pass rng’s to a multi-threaded loop safely? For example, the following code will fail with large K. function thread\_samples(K) rng = MersenneTwister(1) samples = zeros(Int64, K) Threads.@…

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## [VS Code Julia -- inline detail is not shown after execution](https://discourse.julialang.org/t/vs-code-julia-inline-detail-is-not-shown-after-execution/46284)

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**Author:** [@psabela](https://discourse.julialang.org/u/psabela)\
**Replies:** 3\
**Last updated:** [September 14, 2020, 4:01am UTC](https://discourse.julialang.org/t/vs-code-julia-inline-detail-is-not-shown-after-execution/46284 "2020-09-14T04:01:35Z")

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How do I get the extra inline detail to the right of the following statement after execution: cars = dataset(“cars”) |406x9 Vega dataset

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## [Performance improvements for simple molecular surface caclulation](https://discourse.julialang.org/t/performance-improvements-for-simple-molecular-surface-caclulation/46514)

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**Author:** [@v-a-s-a](https://discourse.julialang.org/u/v-a-s-a)\
**Replies:** 15\
**Last updated:** [September 14, 2020, 12:29am UTC](https://discourse.julialang.org/t/performance-improvements-for-simple-molecular-surface-caclulation/46514 "2020-09-14T00:29:08Z")

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I have a fairly straightforward calculation I’ve been playing around with, and it seems like a good opportunity to learn a little more about typical optimizations people reach for, as well as coding style. At the core, …

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## [Making a collection of JuMP models using pmap](https://discourse.julialang.org/t/making-a-collection-of-jump-models-using-pmap/46530)

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**Author:** [@adow031](https://discourse.julialang.org/u/adow031)\
**Replies:** 4\
**Last updated:** [September 13, 2020, 10:26pm UTC](https://discourse.julialang.org/t/making-a-collection-of-jump-models-using-pmap/46530 "2020-09-13T22:26:28Z")

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I’m trying to create a number of JuMP models in parallel using pmap, and while the basic functionality of this is working fine, my implementation stores some variables and expressions in the ext field of the JuMP.Model. …

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## [Is there any overhead through too many threads?](https://discourse.julialang.org/t/is-there-any-overhead-through-too-many-threads/46559)

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**Author:** [@fgerick](https://discourse.julialang.org/u/fgerick)\
**Replies:** 7\
**Last updated:** [September 13, 2020, 9:42pm UTC](https://discourse.julialang.org/t/is-there-any-overhead-through-too-many-threads/46559 "2020-09-13T21:42:39Z")

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Hi everyone, sorry if this has already been answered somewhere, but my quick search didn’t really give me an answer. I was wondering if there is any possible performance regression when setting JULIA\_NUM\_THREADS larger…

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## [Unmarshalling to a Julia type when type has Union in the Attribute values?](https://discourse.julialang.org/t/unmarshalling-to-a-julia-type-when-type-has-union-in-the-attribute-values/46563)

<div class="topic-metadata">

**Author:** [@DataPsycho](https://discourse.julialang.org/u/DataPsycho)\
**Replies:** 1\
**Last updated:** [September 13, 2020, 9:06pm UTC](https://discourse.julialang.org/t/unmarshalling-to-a-julia-type-when-type-has-union-in-the-attribute-values/46563 "2020-09-13T21:06:59Z")

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Hi, I am trying to unmarshal a json to a Struct type where there is Union in type attributes but it does not work. Is there a way to do that? That exercise works: using Unmarshal input = "{ \\"id\\": 25073877, \\"id\_str…

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