# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1279

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

**Page:** 1280

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## [How to enforce spawned tasks to be run on different threads?](https://discourse.julialang.org/t/how-to-enforce-spawned-tasks-to-be-run-on-different-threads/67496)

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**Author:** [@erwanlecarpentier](https://discourse.julialang.org/u/erwanlecarpentier)\
**Replies:** 4\
**Last updated:** [September 1, 2021, 1:48pm UTC](https://discourse.julialang.org/t/how-to-enforce-spawned-tasks-to-be-run-on-different-threads/67496 "2021-09-01T13:48:22Z")

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Hey! I would like to run a job several times in parallel (as many times as the number of available threads), and I would like to do this several times in a row. MWE: function mytask() # The task to be parallelized …

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## [Is it possible to wrap up the error message in Pluto?](https://discourse.julialang.org/t/is-it-possible-to-wrap-up-the-error-message-in-pluto/67500)

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**Author:** [@GoH](https://discourse.julialang.org/u/GoH)\
**Replies:** 0\
**Last updated:** [September 1, 2021, 1:48pm UTC](https://discourse.julialang.org/t/is-it-possible-to-wrap-up-the-error-message-in-pluto/67500 "2021-09-01T13:48:08Z")

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just a quick question, sometimes I got a very long error description in Pluto, and it takes sometime for me to navigate. so i’m wondering is it possible to wrap it up, and I can scroll it up and down if I want to look i…

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## [ComponentArrays.jl crashes Julia in VSCode but not in REPL](https://discourse.julialang.org/t/componentarrays-jl-crashes-julia-in-vscode-but-not-in-repl/54667)

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**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 0\
**Last updated:** [February 5, 2021, 2:55am UTC](https://discourse.julialang.org/t/componentarrays-jl-crashes-julia-in-vscode-but-not-in-repl/54667 "2021-02-05T02:55:20Z")

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The following code crashes Julia in VSCode, but the REPL can run it with no problem. using ComponentArrays szE = 2 szG = 2 szA = 9 szK = 5 szT = 44 szB = 2 szZ = 2 costdata = Array{Float64}(undef, szT) wwdata = Array{…

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## [Reverting back to avoid precompile errors?](https://discourse.julialang.org/t/reverting-back-to-avoid-precompile-errors/67354)

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**Author:** [@martin.demare](https://discourse.julialang.org/u/martin.demare)\
**Replies:** 26\
**Last updated:** [September 1, 2021, 12:30pm UTC](https://discourse.julialang.org/t/reverting-back-to-avoid-precompile-errors/67354 "2021-09-01T12:30:27Z")

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Hi, I am doing some work quite unrelated to the reading of CSV-files, however I am very much impacted by the issue described in csv-jl-fails-precompling #67195. Since my preferred package (GeoArrays.jl, which has a dep…

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## [Problem about SDDE solver in differentialequation.jl](https://discourse.julialang.org/t/problem-about-sdde-solver-in-differentialequation-jl/67495)

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**Author:** [@Liwei17](https://discourse.julialang.org/u/Liwei17)\
**Replies:** 1\
**Last updated:** [September 1, 2021, 12:13pm UTC](https://discourse.julialang.org/t/problem-about-sdde-solver-in-differentialequation-jl/67495 "2021-09-01T12:13:47Z")

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Basically, I’m running a SDDE solver. tspan = (0, 50000); prob = SDDEProblem(f, g, u0, h, tspan, p; constant\_lags = lag); sol = solve(prob, RKMil()); I want to get the corresponding tspan time point in “sol”. But I fo…

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## [Find the value of the inverse of a function in some point](https://discourse.julialang.org/t/find-the-value-of-the-inverse-of-a-function-in-some-point/67479)

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**Author:** [@maoc](https://discourse.julialang.org/u/maoc)\
**Replies:** 3\
**Last updated:** [September 1, 2021, 11:36am UTC](https://discourse.julialang.org/t/find-the-value-of-the-inverse-of-a-function-in-some-point/67479 "2021-09-01T11:36:47Z")

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I have a particular function and I want to calculate its inverse. My function is locally injective and I want to calculate its inverse, more specifically, values. For example, suppose my function is f such that f(0.1) = …

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## [Can't get CSV package working in 1.6.2](https://discourse.julialang.org/t/cant-get-csv-package-working-in-1-6-2/67490)

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**Author:** [@compleat](https://discourse.julialang.org/u/compleat)\
**Replies:** 1\
**Last updated:** [September 1, 2021, 11:33am UTC](https://discourse.julialang.org/t/cant-get-csv-package-working-in-1-6-2/67490 "2021-09-01T11:33:32Z")

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After standard installation of 1.6.2 on Ubuntu 20, I tried adding and (later) building the CSV package. Each ran OK but failed on invocations of ‘using’. using CSV \\u250c Info: Precompiling CSV \[336ed68f-0bac-5ca0-87…

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## [Speed up matrix multiplication with permuted vector](https://discourse.julialang.org/t/speed-up-matrix-multiplication-with-permuted-vector/67491)

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**Author:** [@Thomas](https://discourse.julialang.org/u/Thomas)\
**Replies:** 5\
**Last updated:** [September 1, 2021, 11:24am UTC](https://discourse.julialang.org/t/speed-up-matrix-multiplication-with-permuted-vector/67491 "2021-09-01T11:24:51Z")

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I have a very large sparse matrix of the order (1768, 39816100) that goes into the following (part of Computing sparse orthogonal projections - #2 by stevengj): QR = qr(A::SparseMatrixCSC) # A = sparse matrix of size (1…

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## [Where is my memory usage coming from](https://discourse.julialang.org/t/where-is-my-memory-usage-coming-from/67351)

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**Author:** [@maarten\_van\_damme](https://discourse.julialang.org/u/maarten_van_damme)\
**Replies:** 12\
**Last updated:** [September 1, 2021, 9:33am UTC](https://discourse.julialang.org/t/where-is-my-memory-usage-coming-from/67351 "2021-09-01T09:33:31Z")

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While developing a package, I noticed that a simulation that used to run without problems now takes a whopping 30+ gb. The script is rather simple, I use some packages and then execute a let block. There should be no lea…

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## [Updating a value in JLD2](https://discourse.julialang.org/t/updating-a-value-in-jld2/29702)

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**Author:** [@pixel27](https://discourse.julialang.org/u/pixel27)\
**Replies:** 1\
**Last updated:** [September 1, 2021, 8:31am UTC](https://discourse.julialang.org/t/updating-a-value-in-jld2/29702 "2021-09-01T08:31:05Z")

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Is it possible to update a value written to a JLD2 file? With version 1 there was a delete! method to delete the old value before writing it’s new value. With v2 I don’t see that method. I’ve looked for other methods i…

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## [EOFError: read end of file JLD2](https://discourse.julialang.org/t/eoferror-read-end-of-file-jld2/59693)

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**Author:** [@Sebastian\_Mena](https://discourse.julialang.org/u/Sebastian_Mena)\
**Replies:** 1\
**Last updated:** [September 1, 2021, 8:29am UTC](https://discourse.julialang.org/t/eoferror-read-end-of-file-jld2/59693 "2021-09-01T08:29:37Z")

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Hi, I tried to import a dictionary into jupyter notebook (julia 1.5.1), but it threw me this error: \>import JLD2 \>dict\_duels\_accurate\_probs = load("path/dict\_duels\_accurate\_probs.jld2") Error encountered while loading…

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## [Plot size changes depending on installed packages](https://discourse.julialang.org/t/plot-size-changes-depending-on-installed-packages/67068)

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**Author:** [@ForceBru](https://discourse.julialang.org/u/ForceBru)\
**Replies:** 9\
**Last updated:** [September 1, 2021, 7:40am UTC](https://discourse.julialang.org/t/plot-size-changes-depending-on-installed-packages/67068 "2021-09-01T07:40:49Z")

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I have two Pluto notebooks that are identical except for the line with imports. Yet the plot in the second one is consistently tiny. Notebook with tiny plot First like: using StatsPlots, Distributions, LoopVectorization…

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## [Running time](https://discourse.julialang.org/t/running-time/67462)

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**Author:** [@tortijazz](https://discourse.julialang.org/u/tortijazz)\
**Replies:** 5\
**Last updated:** [September 1, 2021, 6:55am UTC](https://discourse.julialang.org/t/running-time/67462 "2021-09-01T06:55:23Z")

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Hi everybody, I was making simulations with Flux.jl, DiffEqFlux.jl, Optim.jl, DiffEqSensitivity.jl and OrdinaryDiffEq.jl in Julia-1.5.2 and I saw that there was a new stable release (1.6.2 version), so I did upgrade Jul…

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## [Multi-threading and Dierckx.jl & Interpolations.jl and gradients](https://discourse.julialang.org/t/multi-threading-and-dierckx-jl-interpolations-jl-and-gradients/67452)

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**Author:** [@gianmariomanca](https://discourse.julialang.org/u/gianmariomanca)\
**Replies:** 6\
**Last updated:** [September 1, 2021, 6:15am UTC](https://discourse.julialang.org/t/multi-threading-and-dierckx-jl-interpolations-jl-and-gradients/67452 "2021-09-01T06:15:55Z")

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I noticed that if I use https://github.com/kbarbary/Dierckx.jl (1D, k=3 and derivatives) in a loop with the Threads.@threads macro I get partially corrupted results. If I remove the Threads.@threads macro results look f…

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## [Behavior of Julia package manager, deleting folders in registeries/General very frequently, unacceptable](https://discourse.julialang.org/t/behavior-of-julia-package-manager-deleting-folders-in-registeries-general-very-frequently-unacceptable/67468)

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**Author:** [@Lian\_Yunlong](https://discourse.julialang.org/u/Lian_Yunlong)\
**Replies:** 6\
**Last updated:** [September 1, 2021, 3:19am UTC](https://discourse.julialang.org/t/behavior-of-julia-package-manager-deleting-folders-in-registeries-general-very-frequently-unacceptable/67468 "2021-09-01T03:19:58Z")

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Dear Julia developers and experts, I am a scientific researcher and a regular Julia user. I often run Julia programs on HPC. During the development of my own package, I need to add other packages from time to time. Ever…

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## [Can't understand what LoopVectorization is doing](https://discourse.julialang.org/t/cant-understand-what-loopvectorization-is-doing/67439)

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**Author:** [@Gregstrq](https://discourse.julialang.org/u/Gregstrq)\
**Replies:** 7\
**Last updated:** [September 1, 2021, 2:18am UTC](https://discourse.julialang.org/t/cant-understand-what-loopvectorization-is-doing/67439 "2021-09-01T02:18:35Z")

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I’ve stumbled upon something which looks like black magic to me. I am solving an ODE, where the right-hand-side function needs to evaluate a large sum, which can be paralleled over a number of threads. I have replaced T…

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## [How to define structure with its field is matrix?](https://discourse.julialang.org/t/how-to-define-structure-with-its-field-is-matrix/67450)

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**Author:** [@Amro](https://discourse.julialang.org/u/Amro)\
**Replies:** 8\
**Last updated:** [August 31, 2021, 11:09pm UTC](https://discourse.julialang.org/t/how-to-define-structure-with-its-field-is-matrix/67450 "2021-08-31T23:09:08Z")

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I have a structure as below: struct R value::Vector{Float64} = \[\] end however, I want to make the “value” to be matrix (undefined,3) with elements type as “Float64” so I adjusted as below: struct R value::Arra…

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## [Change color of specific bar in a bar plot](https://discourse.julialang.org/t/change-color-of-specific-bar-in-a-bar-plot/67459)

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**Author:** [@vtomar](https://discourse.julialang.org/u/vtomar)\
**Replies:** 1\
**Last updated:** [August 31, 2021, 10:32pm UTC](https://discourse.julialang.org/t/change-color-of-specific-bar-in-a-bar-plot/67459 "2021-08-31T22:32:24Z")

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Below is some sample code using Makie that generates horizontal bar plots in blue color. I want to color one of the bars to be with a different color. How would I do that? The bar that needs to be colored: The y axis val…

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## [Does Julia cache version of function with given input value?](https://discourse.julialang.org/t/does-julia-cache-version-of-function-with-given-input-value/67445)

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**Author:** [@Thomas](https://discourse.julialang.org/u/Thomas)\
**Replies:** 7\
**Last updated:** [August 31, 2021, 9:24pm UTC](https://discourse.julialang.org/t/does-julia-cache-version-of-function-with-given-input-value/67445 "2021-08-31T21:24:02Z")

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Say I am doing y = x\[perm\] for a permutation perm. I believe that Julia would dispatch and compile a version of getindex(x, perm) for the type that I called. Now if I call y1 = x1\[perm\] again for the same types but diffe…

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## [Product of two symmetric matrices: LoopVectorization.jl vs LinearAlgebra](https://discourse.julialang.org/t/product-of-two-symmetric-matrices-loopvectorization-jl-vs-linearalgebra/67396)

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**Author:** [@fipelle](https://discourse.julialang.org/u/fipelle)\
**Replies:** 9\
**Last updated:** [August 31, 2021, 8:11pm UTC](https://discourse.julialang.org/t/product-of-two-symmetric-matrices-loopvectorization-jl-vs-linearalgebra/67396 "2021-08-31T20:11:59Z")

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Hi, I am playing around with LoopVectorization.jl. In doing so, I have noticed that it seems to be about 1.5x faster than LinearAlgebra in computing the product between two symmetric matrices (while being about as fast …

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## [Plot beyond gridlines](https://discourse.julialang.org/t/plot-beyond-gridlines/67438)

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**Author:** [@jzr](https://discourse.julialang.org/u/jzr)\
**Replies:** 3\
**Last updated:** [August 31, 2021, 7:42pm UTC](https://discourse.julialang.org/t/plot-beyond-gridlines/67438 "2021-08-31T19:42:33Z")

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using WGLMakie n = 500 x = 1:n y = randn(n) fig = Figure() ax = Axis( fig\[1,1\], limits=(nothing, (-1.5, 1.5)), xgridcolor=:red, leftspinevisible=false, rightspinevisible=false, topspinevisible=…

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## [New Makie website](https://discourse.julialang.org/t/new-makie-website/67284)

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**Author:** [@jules](https://discourse.julialang.org/u/jules)\
**Replies:** 5\
**Last updated:** [August 31, 2021, 7:40pm UTC](https://discourse.julialang.org/t/new-makie-website/67284 "2021-08-31T19:40:53Z")

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We have a new website for Makie, built with Franklin.jl http://makie.juliaplots.org/ The new site has overview galleries for plotting functions and layoutables, and is organized a bit more clearly. It’s still a work in…

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## [Hide axis labels](https://discourse.julialang.org/t/hide-axis-labels/67443)

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**Author:** [@jzr](https://discourse.julialang.org/u/jzr)\
**Replies:** 2\
**Last updated:** [August 31, 2021, 7:34pm UTC](https://discourse.julialang.org/t/hide-axis-labels/67443 "2021-08-31T19:34:38Z")

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using WGLMakie n = 500 x = 1:n y = randn(n) c = rand('a':'d', n) spec = data((;x,y,c)) \* visual(Scatter) \* mapping(:x, :y, row=:c) draw(spec, axis=(; ylabelvisible=false)) How can I hide each of these labels? y -…

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## [@cfunction within function, scoping problem](https://discourse.julialang.org/t/cfunction-within-function-scoping-problem/66484)

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**Author:** [@dbertini](https://discourse.julialang.org/u/dbertini)\
**Replies:** 10\
**Last updated:** [August 31, 2021, 7:09pm UTC](https://discourse.julialang.org/t/cfunction-within-function-scoping-problem/66484 "2021-08-31T19:09:59Z")

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Hi it seems that the macro @cfunction work only with function defined in global scope. Used within a function like function get\_ptr(f::Function) integrand\_c = @cfunction( $f,Cdouble,(Ptr{Cdouble},Ptr{Cdouble},Ptr…

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## [Julia and QuestDB](https://discourse.julialang.org/t/julia-and-questdb/67434)

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**Author:** [@dm13450](https://discourse.julialang.org/u/dm13450)\
**Replies:** 2\
**Last updated:** [August 31, 2021, 5:29pm UTC](https://discourse.julialang.org/t/julia-and-questdb/67434 "2021-08-31T17:29:57Z")

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I’ve written two blog posts about using Julia with QuestDB. This is a type of database that specialises in time series data, so in part 1 I’ve written about connecting to a WebSocket to ingest streaming data into QuestD…

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## [ReferenceTests for a Matrix](https://discourse.julialang.org/t/referencetests-for-a-matrix/67431)

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**Author:** [@Brad\_Carman](https://discourse.julialang.org/u/Brad_Carman)\
**Replies:** 1\
**Last updated:** [August 31, 2021, 5:23pm UTC](https://discourse.julialang.org/t/referencetests-for-a-matrix/67431 "2021-08-31T17:23:17Z")

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I’m struggling to figure out how to use @test\_reference from ReferenceTests.jl for a Matrix{Float64} type. If I do @test\_reference "data.dat" data then the data is stored as a string and compared as a string. This m…

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## [Correct way of: f(::T) where T = zero(T)?](https://discourse.julialang.org/t/correct-way-of-f-t-where-t-zero-t/67426)

<div class="topic-metadata">

**Author:** [@lmiq](https://discourse.julialang.org/u/lmiq)\
**Replies:** 2\
**Last updated:** [August 31, 2021, 5:14pm UTC](https://discourse.julialang.org/t/correct-way-of-f-t-where-t-zero-t/67426 "2021-08-31T17:14:31Z")

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What is the correct way to pass only a type to control dispatch and use that type inside the function? As the title says, I want to do something like: f(::T) where T = zero(T) Is this one? julia\> f(T::DataType) = zer…

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## [What does "surprising behaviors" in the documentation of ITensor mean?](https://discourse.julialang.org/t/what-does-surprising-behaviors-in-the-documentation-of-itensor-mean/67408)

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**Author:** [@wujinq](https://discourse.julialang.org/u/wujinq)\
**Replies:** 2\
**Last updated:** [August 31, 2021, 5:09pm UTC](https://discourse.julialang.org/t/what-does-surprising-behaviors-in-the-documentation-of-itensor-mean/67408 "2021-08-31T17:09:48Z")

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In this page it is said that The reason we recommend the let...end block is that code written in the Julia global scope can have some surprising behaviors. Putting your code into a let block avoids these issues. What…

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## [How to control group sorting in boxplot?](https://discourse.julialang.org/t/how-to-control-group-sorting-in-boxplot/67432)

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**Author:** [@gedankenexperiment](https://discourse.julialang.org/u/gedankenexperiment)\
**Replies:** 2\
**Last updated:** [August 31, 2021, 4:38pm UTC](https://discourse.julialang.org/t/how-to-control-group-sorting-in-boxplot/67432 "2021-08-31T16:38:10Z")

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How can I control the order in which groups are sorted along the x-axis? The xsort attribute seems to be deprecated, cf. How to adjust the X-axis order of boxplot with StatsPlots.jl - #9 by Shuhua I’m using Julia v1.6 a…

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## [Neural ODE with Evolutionary Parameters](https://discourse.julialang.org/t/neural-ode-with-evolutionary-parameters/65736)

<div class="topic-metadata">

**Author:** [@Saad](https://discourse.julialang.org/u/Saad)\
**Replies:** 7\
**Last updated:** [August 31, 2021, 4:17pm UTC](https://discourse.julialang.org/t/neural-ode-with-evolutionary-parameters/65736 "2021-08-31T16:17:02Z")

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Hello everyone, I would like to know if there is a package on Julia adapted to Neural ODEs with time dependent parameters, or if there is a practical example of code use to allow evolution of the neural network paramete…

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