# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1661

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

**Page:** 1662

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## [RROR: UndefVarError: insertcolafter not defined in JuliaDB](https://discourse.julialang.org/t/rror-undefvarerror-insertcolafter-not-defined-in-juliadb/44810)

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**Author:** [@hafez\_ahmad](https://discourse.julialang.org/u/hafez_ahmad)\
**Replies:** 2\
**Last updated:** [August 12, 2020, 3:11pm UTC](https://discourse.julialang.org/t/rror-undefvarerror-insertcolafter-not-defined-in-juliadb/44810 "2020-08-12T15:11:59Z")

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I am using Julia 1.5 in windows 10. I am just reading and practicing JuliaDB \> t = table(\[0.01, 0.05\], \[2,1\], \[3,4\], names=\[:t, :x, :y\], pkey=:t) \> \> insertcolafter(t, :t, :w, \[0,1\]) \> ERROR: UndefVarError: insertcol…

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## [Why does Distances 0.9.0 depends on Plots 1.5.7](https://discourse.julialang.org/t/why-does-distances-0-9-0-depends-on-plots-1-5-7/44784)

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**Author:** [@StevenSiew](https://discourse.julialang.org/u/StevenSiew)\
**Replies:** 6\
**Last updated:** [August 12, 2020, 3:05pm UTC](https://discourse.julialang.org/t/why-does-distances-0-9-0-depends-on-plots-1-5-7/44784 "2020-08-12T15:05:16Z")

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I dont understand why the package Distances which calculates euclidean distances would depends on Plot 1.5.7 I could not figure out what in Plots 1.5.8 broke Distances 0.9.0 (@v1.5) pkg\> up Updating registry at \`~/.…

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## [Noteworthy differences from Fortran](https://discourse.julialang.org/t/noteworthy-differences-from-fortran/44502)

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**Author:** [@zyth0s](https://discourse.julialang.org/u/zyth0s)\
**Replies:** 38\
**Last updated:** [August 12, 2020, 3:01pm UTC](https://discourse.julialang.org/t/noteworthy-differences-from-fortran/44502 "2020-08-12T15:01:45Z")

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I have noticed that there is no short list of noteworthy differences with Fortran in the documentation: Noteworthy Differences from other Languages · The Julia Language Considering that many Fortran programmers would b…

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## [Type error when using sciml\_train with a stiff ODE solver](https://discourse.julialang.org/t/type-error-when-using-sciml-train-with-a-stiff-ode-solver/44763)

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**Author:** [@told](https://discourse.julialang.org/u/told)\
**Replies:** 2\
**Last updated:** [August 12, 2020, 2:44pm UTC](https://discourse.julialang.org/t/type-error-when-using-sciml-train-with-a-stiff-ode-solver/44763 "2020-08-12T14:44:20Z")

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I’m using Julia since today so I might miss something fundamental. I recently discovered the UDE for SciML paper and the super nice SciML library. I try to rebuild something similar to the Lotka-Voltera example from the …

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## [Can't link to libcxxwrap\_julia on MacOS](https://discourse.julialang.org/t/cant-link-to-libcxxwrap-julia-on-macos/43657)

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**Author:** [@liuyxpp](https://discourse.julialang.org/u/liuyxpp)\
**Replies:** 1\
**Last updated:** [August 12, 2020, 2:32pm UTC](https://discourse.julialang.org/t/cant-link-to-libcxxwrap-julia-on-macos/43657 "2020-08-12T14:32:42Z")

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I install and build CxxWrap in the REPL. When I link to it, it fails with message Undefined symbols for architecture x86\_64: “jlcxx::FunctionWrapperBase::FunctionWrapperBase(jlcxx::Module\*, std::pair\<\_jl\_datatype\_t\*, \_…

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## [ERROR: Unsatisfiable requirements detected for package Unitful](https://discourse.julialang.org/t/error-unsatisfiable-requirements-detected-for-package-unitful/44699)

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**Author:** [@jtoledom](https://discourse.julialang.org/u/jtoledom)\
**Replies:** 15\
**Last updated:** [August 12, 2020, 12:28pm UTC](https://discourse.julialang.org/t/error-unsatisfiable-requirements-detected-for-package-unitful/44699 "2020-08-12T12:28:30Z")

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Hi. I’m getting this error when adding the NeuralPDE Pkg. I’m using Julia 1.5 (also tried on 1.0.5 and 1.4.2 and I get a similar log). I don’t know how to interpret it. Any help will be highly appreciated. Don’t know if…

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## [Irrational numbers are unique, so which package gets to define them?](https://discourse.julialang.org/t/irrational-numbers-are-unique-so-which-package-gets-to-define-them/44798)

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**Author:** [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Replies:** 1\
**Last updated:** [August 12, 2020, 12:11pm UTC](https://discourse.julialang.org/t/irrational-numbers-are-unique-so-which-package-gets-to-define-them/44798 "2020-08-12T12:11:27Z")

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Irrational numbers are singleton types and are unique, so we have something like julia\> Irrational{:pi}() === Irrational{:pi}() true Not many irrational numbers are defined in Base, therefore packages are free to defin…

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## [How to quote special characters in run() function](https://discourse.julialang.org/t/how-to-quote-special-characters-in-run-function/21359)

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**Author:** [@Fred](https://discourse.julialang.org/u/Fred)\
**Replies:** 4\
**Last updated:** [August 12, 2020, 12:09pm UTC](https://discourse.julialang.org/t/how-to-quote-special-characters-in-run-function/21359 "2020-08-12T12:09:04Z")

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Hi, I try to execute a shell command with Julia 1.1 on linux with the run() function. julia\> a "f1.txt" julia\> b "f2.txt" julia\> run(\`cat $a \>\> $b\`) ERROR: failed process: Process(\`cat f1.txt '\>\>' f2.txt\`, ProcessExi…

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## [Expected Behavior for Varible Scoping with try/finally?](https://discourse.julialang.org/t/expected-behavior-for-varible-scoping-with-try-finally/44799)

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**Author:** [@RodBiren](https://discourse.julialang.org/u/RodBiren)\
**Replies:** 1\
**Last updated:** [August 12, 2020, 11:25am UTC](https://discourse.julialang.org/t/expected-behavior-for-varible-scoping-with-try-finally/44799 "2020-08-12T11:25:04Z")

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Hello, I am learning Julia and was reading through the docs for Essentials. I ran into behavior that did not seem to match what I expected. Steps to reproduce: Open up REPL Set variable “a” to value “b” Have a try blo…

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## [Resetting TimeLimit of Gurobi Optimizer](https://discourse.julialang.org/t/resetting-timelimit-of-gurobi-optimizer/26627)

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**Author:** [@TheLoooser](https://discourse.julialang.org/u/TheLoooser)\
**Replies:** 4\
**Last updated:** [August 12, 2020, 11:23am UTC](https://discourse.julialang.org/t/resetting-timelimit-of-gurobi-optimizer/26627 "2020-08-12T11:23:06Z")

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I am currently using JuMP with the Gurobi Solver to optimise a tournament schedule. I use a local search heuristic to try and solve each round in a given time limit after having found a first feasible solution. The probl…

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## [Function wrapper with parameterse from struct](https://discourse.julialang.org/t/function-wrapper-with-parameterse-from-struct/44794)

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**Author:** [@Znerual](https://discourse.julialang.org/u/Znerual)\
**Replies:** 2\
**Last updated:** [August 12, 2020, 11:09am UTC](https://discourse.julialang.org/t/function-wrapper-with-parameterse-from-struct/44794 "2020-08-12T11:09:59Z")

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Dear all, I’m trying to figure out how to nicely wrap my function into a struct (or possible other type), which holds all the parameters I want to set before the function is called. The idea around that is that I’m pas…

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## [Unable to enter Pkg REPL](https://discourse.julialang.org/t/unable-to-enter-pkg-repl/44786)

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**Author:** [@cliang](https://discourse.julialang.org/u/cliang)\
**Replies:** 4\
**Last updated:** [August 12, 2020, 10:32am UTC](https://discourse.julialang.org/t/unable-to-enter-pkg-repl/44786 "2020-08-12T10:32:04Z")

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julia\> \] ERROR: syntax: unexpected "\]" Stacktrace: \[1\] top-level scope at none:1 According to the document Pkg comes with a REPL. Enter the Pkg REPL by pressing \] from the Julia REPL. To get back to the Julia REPL…

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## [\[ANN\] Runner.jl: Run with commandline args from REPL](https://discourse.julialang.org/t/ann-runner-jl-run-with-commandline-args-from-repl/44796)

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**Author:** [@v-i-s-h](https://discourse.julialang.org/u/v-i-s-h)\
**Replies:** 1\
**Last updated:** [August 12, 2020, 10:27am UTC](https://discourse.julialang.org/t/ann-runner-jl-run-with-commandline-args-from-repl/44796 "2020-08-12T10:27:16Z")

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Hi, I am pleased to announce a small package which will help in running codes with command line args from REPL. Recently, I have been working with Plots, Flux etc, where the package load time is quite high. While loadin…

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## [Advice on over- vs. proper use of type parameters](https://discourse.julialang.org/t/advice-on-over-vs-proper-use-of-type-parameters/44779)

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**Author:** [@nben](https://discourse.julialang.org/u/nben)\
**Replies:** 2\
**Last updated:** [August 12, 2020, 10:12am UTC](https://discourse.julialang.org/t/advice-on-over-vs-proper-use-of-type-parameters/44779 "2020-08-12T10:12:15Z")

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I am writing an immutable type in Julia and have realized while working on it that I have an opportunity to go a little crazy with the type parameters. Here’s a contrived example that deals with the same problem. I’m cur…

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## [Generic API to reconstruct from factorize](https://discourse.julialang.org/t/generic-api-to-reconstruct-from-factorize/44748)

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**Author:** [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)\
**Replies:** 2\
**Last updated:** [August 12, 2020, 10:03am UTC](https://discourse.julialang.org/t/generic-api-to-reconstruct-from-factorize/44748 "2020-08-12T10:03:26Z")

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Is there a generic function/API to recover the original matrix from a factorization? Eg LinearAlgebra defines Matrix in various places, so A = randn(5, 5) F = factorize(A) Matrix(F) # \<- is there a generic API here? wo…

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## [Flux in Julia 1.5](https://discourse.julialang.org/t/flux-in-julia-1-5/44428)

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**Author:** [@Ruan\_Stander](https://discourse.julialang.org/u/Ruan_Stander)\
**Replies:** 4\
**Last updated:** [August 12, 2020, 10:01am UTC](https://discourse.julialang.org/t/flux-in-julia-1-5/44428 "2020-08-12T10:01:54Z")

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downloaded Julia 1.5 added Flux first time using Flux gives this error Any advice o how to get Flux going on Julia 1.5? julia\> using Flux \[ Info: Precompiling Flux \[587475ba-b771-5e3f-ad9e-33799f191a9c\] Downloading…

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## [Got ArgumentError: Type must be isbitstype when code with MPI](https://discourse.julialang.org/t/got-argumenterror-type-must-be-isbitstype-when-code-with-mpi/44749)

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**Author:** [@Ke\_Gao](https://discourse.julialang.org/u/Ke_Gao)\
**Replies:** 6\
**Last updated:** [August 12, 2020, 9:49am UTC](https://discourse.julialang.org/t/got-argumenterror-type-must-be-isbitstype-when-code-with-mpi/44749 "2020-08-12T09:49:15Z")

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Hi guys, I got an ArgumentError: Type must be isbitstype when I tried to work with MPI.jl. Here is a piece of code: for row in eachrow(init\_ele) println(i) send\_mesg = vec(convert(Array, row)) println(sen…

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## [JuMP constraints independent of a particular model](https://discourse.julialang.org/t/jump-constraints-independent-of-a-particular-model/38314)

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**Author:** [@Tomas\_Uribe](https://discourse.julialang.org/u/Tomas_Uribe)\
**Replies:** 9\
**Last updated:** [August 12, 2020, 9:46am UTC](https://discourse.julialang.org/t/jump-constraints-independent-of-a-particular-model/38314 "2020-08-12T09:46:19Z")

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Is there a way to represent a JuMP constraint independently of a specific model (even if it is purely syntactic)? The macros for creating variables and constraints require a model, of course… What would be a convenient m…

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## [Error using Turing + ReverseDiff with PyJulia](https://discourse.julialang.org/t/error-using-turing-reversediff-with-pyjulia/44791)

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**Author:** [@vyasakanksha](https://discourse.julialang.org/u/vyasakanksha)\
**Replies:** 0\
**Last updated:** [August 12, 2020, 8:55am UTC](https://discourse.julialang.org/t/error-using-turing-reversediff-with-pyjulia/44791 "2020-08-12T08:55:41Z")

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I am getting an error when I use Turing and Reverse Diff with Pyjulia, shown below. Does anyone have any experience getting this to work? Also created a MWE here: https://gist.github.com/vyasakanksha/500d611a28e02c18a31…

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## [A possible way to improve training in Flux?](https://discourse.julialang.org/t/a-possible-way-to-improve-training-in-flux/44629)

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**Author:** [@SambitMishra98](https://discourse.julialang.org/u/SambitMishra98)\
**Replies:** 15\
**Last updated:** [August 12, 2020, 7:44am UTC](https://discourse.julialang.org/t/a-possible-way-to-improve-training-in-flux/44629 "2020-08-12T07:44:42Z")

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Let’s say I need my weights to be determined with an accuracy of 10^10 and hence want to train my network using Float64. Does it make sense to train my network with Float32 and then (after I get around 10^-7 accurac…

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## [Stochastic DDEs?](https://discourse.julialang.org/t/stochastic-ddes/24338)

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**Author:** [@maedoc](https://discourse.julialang.org/u/maedoc)\
**Replies:** 9\
**Last updated:** [August 12, 2020, 7:12am UTC](https://discourse.julialang.org/t/stochastic-ddes/24338 "2020-08-12T07:12:04Z")

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hi I’m new to Julia, but looking to port a neural mass network model with both delays & (linear additive) stochastic forcing (which I’ve solved elsewhere by adding delays by hand to typical SDE methods). Looking throug…

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## [Heatmap weird error in Plots.jl](https://discourse.julialang.org/t/heatmap-weird-error-in-plots-jl/44772)

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**Author:** [@VMHidalgo](https://discourse.julialang.org/u/VMHidalgo)\
**Replies:** 7\
**Last updated:** [August 12, 2020, 6:10am UTC](https://discourse.julialang.org/t/heatmap-weird-error-in-plots-jl/44772 "2020-08-12T06:10:53Z")

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Hi , I would like to ask for your support cause I am getting an error I have never seen before. My code… using Plots gr() xs = \[string("x", i) for i = 1:10\] ys = \[string("y", i) for i = 1:4\] z = float((1:4) \* reshap…

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## [Package for byte swapping](https://discourse.julialang.org/t/package-for-byte-swapping/44782)

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**Author:** [@Zach\_Christensen](https://discourse.julialang.org/u/Zach_Christensen)\
**Replies:** 0\
**Last updated:** [August 12, 2020, 5:50am UTC](https://discourse.julialang.org/t/package-for-byte-swapping/44782 "2020-08-12T05:50:17Z")

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Are there any packages that handle byte swapping a stream of data automatically? I asked about this a while ago on Zulip and it didn’t seem like there were any solutions available at the time, so I just put together the …

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## [ANN: UnitfulMoles.jl](https://discourse.julialang.org/t/ann-unitfulmoles-jl/44666)

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**Author:** [@Raf](https://discourse.julialang.org/u/Raf)\
**Replies:** 2\
**Last updated:** [August 12, 2020, 3:53am UTC](https://discourse.julialang.org/t/ann-unitfulmoles-jl/44666 "2020-08-12T03:53:04Z")

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Announcing UnitfulMoles.jl! UnitfulMoles.jl allows you to use and define specific molar quantities in your equations. Instead of using u"mol/mol" and similar, you can use u"molCO2/molH20". You can also do conversion to …

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## [Define function with begin or with let?](https://discourse.julialang.org/t/define-function-with-begin-or-with-let/44767)

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**Author:** [@PetrKryslUCSD](https://discourse.julialang.org/u/PetrKryslUCSD)\
**Replies:** 2\
**Last updated:** [August 11, 2020, 10:59pm UTC](https://discourse.julialang.org/t/define-function-with-begin-or-with-let/44767 "2020-08-11T22:59:09Z")

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Consider these two functions f(x) = begin x^2 end g(x) = let x^2 end using InteractiveUtils @code\_warntype f(1) @code\_warntype g(1) The compiler seems to generate the same code for both functions. So my ques…

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## [Quadrature from x=0 to x=Inf?](https://discourse.julialang.org/t/quadrature-from-x-0-to-x-inf/44751)

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**Author:** [@BLI](https://discourse.julialang.org/u/BLI)\
**Replies:** 11\
**Last updated:** [August 11, 2020, 9:38pm UTC](https://discourse.julialang.org/t/quadrature-from-x-0-to-x-inf/44751 "2020-08-11T21:38:03Z")

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I have previously used QuadGK over a finite interval. Now I need to do numeric integration from x=0 to x=Inf, and wonder if there is a routine that supports this? \[I need to check scaling, etc. of the “continuous” Poisso…

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## [Performance inv & solve in Julia & R](https://discourse.julialang.org/t/performance-inv-solve-in-julia-r/44625)

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**Author:** [@PharmCat](https://discourse.julialang.org/u/PharmCat)\
**Replies:** 15\
**Last updated:** [August 11, 2020, 9:26pm UTC](https://discourse.julialang.org/t/performance-inv-solve-in-julia-r/44625 "2020-08-11T21:26:47Z")

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How can it be: Matrix inv(A) where A 150x150 matrix twice slower (2.643 ms) than in R (1.049 ms). But invercing by blocks in R ( 3.275 ms) slower than in Julia (58.917 μs) many times. Second not surprising, but first… …

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## [How to make Pkg remember github creds](https://discourse.julialang.org/t/how-to-make-pkg-remember-github-creds/44760)

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**Author:** [@mkarikom](https://discourse.julialang.org/u/mkarikom)\
**Replies:** 0\
**Last updated:** [August 11, 2020, 9:05pm UTC](https://discourse.julialang.org/t/how-to-make-pkg-remember-github-creds/44760 "2020-08-11T21:05:01Z")

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Say I need to pull in a package from a private repo: (myproj) pkg\> add https://github.com/org/package.jl Cloning git-repo \`https://github.com/org/package.jl\` Username for 'https://github.com': org Password for 'http…

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## [Creating an abstract type as a wrapper for types different functions that serve the same purpose](https://discourse.julialang.org/t/creating-an-abstract-type-as-a-wrapper-for-types-different-functions-that-serve-the-same-purpose/44758)

<div class="topic-metadata">

**Author:** [@gottacatchenall](https://discourse.julialang.org/u/gottacatchenall)\
**Replies:** 1\
**Last updated:** [August 11, 2020, 8:36pm UTC](https://discourse.julialang.org/t/creating-an-abstract-type-as-a-wrapper-for-types-different-functions-that-serve-the-same-purpose/44758 "2020-08-11T20:36:59Z")

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I’m trying to create an abstract type that is a superclass (called Kernel) several different of functions, each a subclass of Kernel --i.e. abstract type Kernel end struct ExponentialKernel \<: Kernel ExponentialKer…

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## [Does Query.jl have a good way to implement mutations that depend on each other?](https://discourse.julialang.org/t/does-query-jl-have-a-good-way-to-implement-mutations-that-depend-on-each-other/44643)

<div class="topic-metadata">

**Author:** [@ilyagr](https://discourse.julialang.org/u/ilyagr)\
**Replies:** 3\
**Last updated:** [August 11, 2020, 8:26pm UTC](https://discourse.julialang.org/t/does-query-jl-have-a-good-way-to-implement-mutations-that-depend-on-each-other/44643 "2020-08-11T20:26:16Z")

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The following doesn’t work because latter definitions can’t depend on previous ones: DataFrame(bad=\[1,2\], good=\[0, 3\]) |\> @map(( count = \_.bad + \_.good, bad\_rate = \_.bad/\_.count, bad\_pct =round(\_.bad\_rate\*100;d…

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