# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1695

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

**Page:** 1696

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## [Count cumulative number of unique elements](https://discourse.julialang.org/t/count-cumulative-number-of-unique-elements/42736)

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**Author:** [@tpoisot](https://discourse.julialang.org/u/tpoisot)\
**Replies:** 1\
**Last updated:** [July 8, 2020, 3:10pm UTC](https://discourse.julialang.org/t/count-cumulative-number-of-unique-elements/42736 "2020-07-08T15:10:45Z")

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I am trying to produce a species discovery curve, which is basically the number of unique species observed over time. So, at time t, the value is length(unique(\_.species\_name)) for all observations up to time t - this in…

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## [Modify plot outside of function where created](https://discourse.julialang.org/t/modify-plot-outside-of-function-where-created/42690)

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**Author:** [@Nathan\_Boyer](https://discourse.julialang.org/u/Nathan_Boyer)\
**Replies:** 5\
**Last updated:** [July 8, 2020, 3:04pm UTC](https://discourse.julialang.org/t/modify-plot-outside-of-function-where-created/42690 "2020-07-08T15:04:46Z")

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I have a function below which can accept scalars or arrays. (It seemed easier to write the code to work with both input types rather than creating separate methods. I will gladly accept tips on that too.) It returns a nu…

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## [Force model to discard basis](https://discourse.julialang.org/t/force-model-to-discard-basis/41104)

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**Author:** [@Henrique\_Becker](https://discourse.julialang.org/u/Henrique_Becker)\
**Replies:** 10\
**Last updated:** [July 8, 2020, 2:53pm UTC](https://discourse.julialang.org/t/force-model-to-discard-basis/41104 "2020-07-08T14:53:50Z")

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I am wondering if there is a JuMP/MOI way (this is, solver-agnostic) to discard the simplex basis that is implicitly carried by a Model after an LP was solved by the first time. My problem is that I have a large model t…

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## [Is there a DictTables.jl?](https://discourse.julialang.org/t/is-there-a-dicttables-jl/42700)

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**Author:** [@Amin\_Yahyaabadi](https://discourse.julialang.org/u/Amin_Yahyaabadi)\
**Replies:** 7\
**Last updated:** [July 8, 2020, 1:50pm UTC](https://discourse.julialang.org/t/is-there-a-dicttables-jl/42700 "2020-07-08T13:50:54Z")

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I have a problem in which the data is tabular, but one of the columns is the keys for the rest of the row. For example: │ id │ x2 │ y2 │ │ String │ Int64 │ Int64 │ ┼────────┼───────┼───────┤ │ a │ 1 │…

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## [Cannot add StatsBase package, getting GitError](https://discourse.julialang.org/t/cannot-add-statsbase-package-getting-giterror/42595)

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**Author:** [@Shahmir\_Asif](https://discourse.julialang.org/u/Shahmir_Asif)\
**Replies:** 7\
**Last updated:** [July 8, 2020, 1:17pm UTC](https://discourse.julialang.org/t/cannot-add-statsbase-package-getting-giterror/42595 "2020-07-08T13:17:12Z")

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I am using Julia 1.0. I am trying to add this package but I get this error. I have tried to update package module but that doesn’t help ERROR: GitError(Code:EMERGECONFLICT, Class:Checkout, 4479 conflicts prevent checkou…

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## [Multithreaded parallel prefix scan not faster](https://discourse.julialang.org/t/multithreaded-parallel-prefix-scan-not-faster/42591)

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**Author:** [@Ellipse0934](https://discourse.julialang.org/u/Ellipse0934)\
**Replies:** 5\
**Last updated:** [July 8, 2020, 1:12pm UTC](https://discourse.julialang.org/t/multithreaded-parallel-prefix-scan-not-faster/42591 "2020-07-08T13:12:45Z")

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I am trying to write the parallel prefix scan as a multithreaded CPU function. Since the number of processors is small relative to the length of the array It wouldn’t be fruitful to use Hillis-Steele or Belloch scan. In…

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## [Does using Revise cause julia 1.5.0-rc1 to crash?](https://discourse.julialang.org/t/does-using-revise-cause-julia-1-5-0-rc1-to-crash/42725)

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**Author:** [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Replies:** 1\
**Last updated:** [July 8, 2020, 12:41pm UTC](https://discourse.julialang.org/t/does-using-revise-cause-julia-1-5-0-rc1-to-crash/42725 "2020-07-08T12:41:08Z")

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I’ve just downloaded the glibc binary from the Julia downloads page. This is what I find \_ \_ \_ \_(\_)\_ | Documentation: https://docs.julialang.org (\_) | (\_) (\_) | \_ \_ \_| |\_ \_\_ \_…

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## [How would I filter columns that contain a particular substring?](https://discourse.julialang.org/t/how-would-i-filter-columns-that-contain-a-particular-substring/42721)

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**Author:** [@Julia1](https://discourse.julialang.org/u/Julia1)\
**Replies:** 2\
**Last updated:** [July 8, 2020, 12:41pm UTC](https://discourse.julialang.org/t/how-would-i-filter-columns-that-contain-a-particular-substring/42721 "2020-07-08T12:41:04Z")

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Hi how’s it going? Say I have this dataframe initial = DataFrame(:day=\>\["monday","monday","monday"\],:name=\>\["bob","mike","phillis"\],:temp=\>\["medium","high","low, medium"\],:gender=\>\["male, female","male","female"\]) H…

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## [Question about TimeSeriesClustering](https://discourse.julialang.org/t/question-about-timeseriesclustering/42723)

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**Author:** [@abcde](https://discourse.julialang.org/u/abcde)\
**Replies:** 0\
**Last updated:** [July 8, 2020, 12:19pm UTC](https://discourse.julialang.org/t/question-about-timeseriesclustering/42723 "2020-07-08T12:19:43Z")

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using TimeSeriesClustering ts\_input\_data = load\_timeseries\_data(:CEP\_GER1) Why does it always output my data in the REPL, shouldn’t it output in the workspace? thanks！！！！

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## [Memory allocation in matrix multiplication](https://discourse.julialang.org/t/memory-allocation-in-matrix-multiplication/42707)

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**Author:** [@aaraujo71](https://discourse.julialang.org/u/aaraujo71)\
**Replies:** 2\
**Last updated:** [July 8, 2020, 11:39am UTC](https://discourse.julialang.org/t/memory-allocation-in-matrix-multiplication/42707 "2020-07-08T11:39:53Z")

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I am using matrix multiplication inside large loops and I wonder how I can reduce memory allocation. For example, the following (useless) code function run\_cycle!(R, A, B) for i in 1:1000 R = A\*B end end…

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## [DifferentialEquations and Parameter Estimation with Indicator Variables](https://discourse.julialang.org/t/differentialequations-and-parameter-estimation-with-indicator-variables/42633)

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**Author:** [@Alfie](https://discourse.julialang.org/u/Alfie)\
**Replies:** 4\
**Last updated:** [July 8, 2020, 8:40am UTC](https://discourse.julialang.org/t/differentialequations-and-parameter-estimation-with-indicator-variables/42633 "2020-07-08T08:40:54Z")

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Hi I am new to Julia, sorry for this basic question, I am doing some parameter fitting, and would like to use a binary indicator variable (0/1) to differentiate groups from my data. I have the following code: f…

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## [Positioning in violin plot](https://discourse.julialang.org/t/positioning-in-violin-plot/42678)

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**Author:** [@smonsays](https://discourse.julialang.org/u/smonsays)\
**Replies:** 2\
**Last updated:** [July 8, 2020, 8:39am UTC](https://discourse.julialang.org/t/positioning-in-violin-plot/42678 "2020-07-08T08:39:16Z")

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I would like to add ground truth values to a violin plot. So suppose I knew that for my category "a" the true value is 2.0 and I have a violin plot, I could use scatter like so: violin(repeat(\["a", "b", "c"\], outer=100)…

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## [Getting the "current seriescolor" in a recipe](https://discourse.julialang.org/t/getting-the-current-seriescolor-in-a-recipe/42675)

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**Author:** [@met-j](https://discourse.julialang.org/u/met-j)\
**Replies:** 2\
**Last updated:** [July 8, 2020, 8:29am UTC](https://discourse.julialang.org/t/getting-the-current-seriescolor-in-a-recipe/42675 "2020-07-08T08:29:46Z")

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I am working on a Plots recipe based on the marginalhist example. I would like to make the fillcolor of the histogram subplots dependend on the colorgradient used. While this works manually seriescolor --\> cgrad(:star…

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## [Sending emails from Julia using sendmail](https://discourse.julialang.org/t/sending-emails-from-julia-using-sendmail/26672)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 9\
**Last updated:** [July 8, 2020, 7:45am UTC](https://discourse.julialang.org/t/sending-emails-from-julia-using-sendmail/26672 "2020-07-08T07:45:59Z")

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Hello, which is the simplest way to send basic text emails from a julia script in a server that already has sendmail (PostFix sendmail interface) but without setting up a SMTP server (i.e. without https://github.com/avik…

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## [Detect if current "package" has been activated](https://discourse.julialang.org/t/detect-if-current-package-has-been-activated/26764)

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**Author:** [@pixel27](https://discourse.julialang.org/u/pixel27)\
**Replies:** 14\
**Last updated:** [July 8, 2020, 5:45am UTC](https://discourse.julialang.org/t/detect-if-current-package-has-been-activated/26764 "2020-07-08T05:45:01Z")

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I’m not sure I’m doing this correctly but basically I’m building an “application” not a module. I have a Manifest.toml and Project.toml defined that contain the modules this application uses. So my initial julia file d…

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## [Benchmark in place functions with @btime wasn't set up properly?](https://discourse.julialang.org/t/benchmark-in-place-functions-with-btime-wasnt-set-up-properly/42705)

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**Author:** [@jchen975](https://discourse.julialang.org/u/jchen975)\
**Replies:** 2\
**Last updated:** [July 8, 2020, 4:05am UTC](https://discourse.julialang.org/t/benchmark-in-place-functions-with-btime-wasnt-set-up-properly/42705 "2020-07-08T04:05:52Z")

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I wrote an in-place function that performs the multidimensional Newton-Raphson algorithm, and I’m trying to compare the performance with the original implementation in Matlab. Since I wrote it as an in-place function, I…

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## [Question: DifferentialEquations.jl and Runge-Kutte RK4 error](https://discourse.julialang.org/t/question-differentialequations-jl-and-runge-kutte-rk4-error/42694)

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**Author:** [@teamtelefunken](https://discourse.julialang.org/u/teamtelefunken)\
**Replies:** 4\
**Last updated:** [July 8, 2020, 2:35am UTC](https://discourse.julialang.org/t/question-differentialequations-jl-and-runge-kutte-rk4-error/42694 "2020-07-08T02:35:21Z")

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I’m trying to program a simple matrix-Ricatti ODE solver via the DifferentialEquations.jl package and the RK4 algorithm (I tried the default algorithm as well, to no avail). To benchmark my solver, I’m comparing it to th…

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## [Tricks for parallel computing in Julia](https://discourse.julialang.org/t/tricks-for-parallel-computing-in-julia/42638)

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**Author:** [@Joris\_Pinkse](https://discourse.julialang.org/u/Joris_Pinkse)\
**Replies:** 11\
**Last updated:** [July 7, 2020, 11:12pm UTC](https://discourse.julialang.org/t/tricks-for-parallel-computing-in-julia/42638 "2020-07-07T23:12:41Z")

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The graph above represents execution time per call of the function once in the program below as a function of the number of workers used on a 32 cpu/64 thread machine. The green line (left y axis) represents the progr…

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## [Making a structure that contains a static array](https://discourse.julialang.org/t/making-a-structure-that-contains-a-static-array/42681)

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**Author:** [@alan](https://discourse.julialang.org/u/alan)\
**Replies:** 5\
**Last updated:** [July 7, 2020, 11:09pm UTC](https://discourse.julialang.org/t/making-a-structure-that-contains-a-static-array/42681 "2020-07-07T23:09:19Z")

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I’m trying to make a structure that contains a static array. Here’s a minimal example: using StaticArrays mutable struct Foo{N\<:Integer,T} v :: MVector{N,T} end function Foo(x::N, y::T) where {N\<:Integer,T} w …

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## [Comparing matrix multiplication between Julia and C](https://discourse.julialang.org/t/comparing-matrix-multiplication-between-julia-and-c/42692)

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**Author:** [@saulo.giovani](https://discourse.julialang.org/u/saulo.giovani)\
**Replies:** 2\
**Last updated:** [July 7, 2020, 10:38pm UTC](https://discourse.julialang.org/t/comparing-matrix-multiplication-between-julia-and-c/42692 "2020-07-07T22:38:52Z")

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Hey, community! I was comparing matrix multiplication performance using loops in C and Julia and I would like to know if someone could help me with one doubt about Matrix Acess behavior. I have read in the text “What Eve…

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## [Packages imported in IJulia throw errors that are missing when imported in REPL](https://discourse.julialang.org/t/packages-imported-in-ijulia-throw-errors-that-are-missing-when-imported-in-repl/42683)

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**Author:** [@Qfl3x](https://discourse.julialang.org/u/Qfl3x)\
**Replies:** 9\
**Last updated:** [July 7, 2020, 9:09pm UTC](https://discourse.julialang.org/t/packages-imported-in-ijulia-throw-errors-that-are-missing-when-imported-in-repl/42683 "2020-07-07T21:09:27Z")

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Hello. When using packages from within IJulia, I get error messages of the type: ┌ Info: Precompiling Zygote \[e88e6eb3-aa80-5325-afca-941959d7151f\] └ @ Base loading.jl:1260 ┌ Warning: Package Zygote does not have Array…

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## [Performing vector operations on a specific range of a CuArray](https://discourse.julialang.org/t/performing-vector-operations-on-a-specific-range-of-a-cuarray/39706)

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**Author:** [@ozmaden](https://discourse.julialang.org/u/ozmaden)\
**Replies:** 2\
**Last updated:** [July 7, 2020, 8:11pm UTC](https://discourse.julialang.org/t/performing-vector-operations-on-a-specific-range-of-a-cuarray/39706 "2020-07-07T20:11:48Z")

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Hello everyone! I’m taking my first steps with Julia and programming GPUs, also this is my first post here. So please forgive me if the question is too banal or has been answered before :slight\_smile: I could not find an…

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## [Instantiation of Tuple with value type parameters](https://discourse.julialang.org/t/instantiation-of-tuple-with-value-type-parameters/42673)

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**Author:** [@vlc](https://discourse.julialang.org/u/vlc)\
**Replies:** 15\
**Last updated:** [July 7, 2020, 8:05pm UTC](https://discourse.julialang.org/t/instantiation-of-tuple-with-value-type-parameters/42673 "2020-07-07T20:05:03Z")

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Hi there, I would like to be able to instantiate Tuples with value type parameters, e.g. foo = Tuple{3,4}() that is, similarly to how Val does it bar = Val(3) or baz = Val{3}() I was wondering whether there was wa…

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## [Saving VegaLite Plots](https://discourse.julialang.org/t/saving-vegalite-plots/42575)

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**Author:** [@Chris\_Anderson](https://discourse.julialang.org/u/Chris_Anderson)\
**Replies:** 2\
**Last updated:** [July 7, 2020, 5:46pm UTC](https://discourse.julialang.org/t/saving-vegalite-plots/42575 "2020-07-07T17:46:11Z")

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I’m having some trouble saving plots I’ve created using VegaLite. Here is what I’ve been trying. grph1 |\> save("/PATH/figure.png") I get this error. MethodError: no method matching save\_(::FileIO.File{FileIO.DataForm…

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## [Loading entire jld2 file](https://discourse.julialang.org/t/loading-entire-jld2-file/42610)

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**Author:** [@gideonsimpson](https://discourse.julialang.org/u/gideonsimpson)\
**Replies:** 12\
**Last updated:** [July 7, 2020, 5:40pm UTC](https://discourse.julialang.org/t/loading-entire-jld2-file/42610 "2020-07-07T17:40:20Z")

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If I’ve saved my data to a jld2 format file using FileIO, is there a quick way to just load in the entire file at once? I seem to have to name all the entries in the file one by one.

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## [How to explode a DataFrame cell containing multiple values into separate rows?](https://discourse.julialang.org/t/how-to-explode-a-dataframe-cell-containing-multiple-values-into-separate-rows/42677)

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**Author:** [@Julia1](https://discourse.julialang.org/u/Julia1)\
**Replies:** 7\
**Last updated:** [July 7, 2020, 4:25pm UTC](https://discourse.julialang.org/t/how-to-explode-a-dataframe-cell-containing-multiple-values-into-separate-rows/42677 "2020-07-07T16:25:34Z")

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Hi, I’m working on a project where sometimes I get data coming in with multiple values in one cell. Part of my feature engineering is to calculate the counts per user, and I’m looking for an effective way to explode out …

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## [Large memory allocation in ForwardDiff](https://discourse.julialang.org/t/large-memory-allocation-in-forwarddiff/42581)

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**Author:** [@shiroghost](https://discourse.julialang.org/u/shiroghost)\
**Replies:** 14\
**Last updated:** [July 7, 2020, 3:06pm UTC](https://discourse.julialang.org/t/large-memory-allocation-in-forwarddiff/42581 "2020-07-07T15:06:43Z")

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Hi all, I am a bit new to Julia, so I am sure that I should have a type stability problem somewhere, but I cannot find the mistake… I am trying to determine a simple hessian of a user supplied function. The user gives …

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## [What are expected \[pre\]compile times?](https://discourse.julialang.org/t/what-are-expected-pre-compile-times/42672)

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**Author:** [@evanfields](https://discourse.julialang.org/u/evanfields)\
**Replies:** 3\
**Last updated:** [July 7, 2020, 2:01pm UTC](https://discourse.julialang.org/t/what-are-expected-pre-compile-times/42672 "2020-07-07T14:01:48Z")

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I recently thought I’d try out the 1.5 release candidate when making some figures since rumor has it it’s quite snappy :slight\_smile: I was surprised that on a fresh install, after Pkg.add("Gadfly"), using Gadfly took 14…

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## [Use multithreaded Jacobian function generated with ModelingToolKit.jl for application in DifferentialEquations.jl](https://discourse.julialang.org/t/use-multithreaded-jacobian-function-generated-with-modelingtoolkit-jl-for-application-in-differentialequations-jl/42317)

<div class="topic-metadata">

**Author:** [@luis\_munoz](https://discourse.julialang.org/u/luis_munoz)\
**Replies:** 5\
**Last updated:** [July 7, 2020, 1:45pm UTC](https://discourse.julialang.org/t/use-multithreaded-jacobian-function-generated-with-modelingtoolkit-jl-for-application-in-differentialequations-jl/42317 "2020-07-07T13:45:30Z")

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Hi, I would like to complete the example PDE in the SciML News (also in the ModelingToolKit.jl documentation), section “ModelingToolkit Automatic Parallelism”, on automatically computed multithreaded Jacobian functions…

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## [Helicopter Scientific Machine Learning (SciML) Challenge Problem](https://discourse.julialang.org/t/helicopter-scientific-machine-learning-sciml-challenge-problem/42676)

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**Author:** [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Replies:** 0\
**Last updated:** [July 7, 2020, 1:15pm UTC](https://discourse.julialang.org/t/helicopter-scientific-machine-learning-sciml-challenge-problem/42676 "2020-07-07T13:15:18Z")

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Hey everyone, If you’ve been looking for a fun problem to get into scientific machine learning, check out our new Helicpter SciML Challenge Problem: This challenge problem gives a first principles model (along with i…

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