# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1553

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

**Page:** 1554

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## [Assignment to Matrix](https://discourse.julialang.org/t/assignment-to-matrix/51413)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 3\
**Last updated:** [December 7, 2020, 7:13pm UTC](https://discourse.julialang.org/t/assignment-to-matrix/51413 "2020-12-07T19:13:21Z")

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It seems that assignment to a matrix (as opposed to a tuple) is not supported, right ? function foo() return \[\[\[1,2,3\],"abc",'e'\] \[1, 2, 3\]\] end \[a b; c d; e f\] = foo() #error Is there any simple workaround (other…

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## [Improving IntelliJ IDE Support](https://discourse.julialang.org/t/improving-intellij-ide-support/51425)

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**Author:** [@essenciary](https://discourse.julialang.org/u/essenciary)\
**Replies:** 0\
**Last updated:** [December 7, 2020, 7:13pm UTC](https://discourse.julialang.org/t/improving-intellij-ide-support/51425 "2020-12-07T19:13:52Z")

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Lately I’ve been dabbing a bit into IntelliJ IDEs and I think it would be nice to improve Julia support. The IDEs are actually very snappy (make me believe Java IDEs are less resource intense than Electron ones these day…

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## [Introduction to oneAPI.jl](https://discourse.julialang.org/t/introduction-to-oneapi-jl/51054)

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**Author:** [@vchuravy](https://discourse.julialang.org/u/vchuravy)\
**Replies:** 2\
**Last updated:** [December 7, 2020, 6:10pm UTC](https://discourse.julialang.org/t/introduction-to-oneapi-jl/51054 "2020-12-07T18:10:48Z")

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@maleadt is going to give a short introduction to his recent work on oneAPI.jl at the next virtual JuliaGPU user call. The next user call is at Mon, December 7, 17:00 – 18:00 UTC and the details on how to join can be fo…

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## [Generalized approach for plottting derived quantities](https://discourse.julialang.org/t/generalized-approach-for-plottting-derived-quantities/51388)

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**Author:** [@henry2004y](https://discourse.julialang.org/u/henry2004y)\
**Replies:** 11\
**Last updated:** [December 7, 2020, 5:25pm UTC](https://discourse.julialang.org/t/generalized-approach-for-plottting-derived-quantities/51388 "2020-12-07T17:25:06Z")

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Hi fellows, I have a code design problem for handling derived variables in my plotting package. Say I already have a function plot that can generate figures for variable a. Let’s assume we now have another variable of …

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## [Why Are Languages Like Python and MATLAB So Much Slower than Julia?](https://discourse.julialang.org/t/why-are-languages-like-python-and-matlab-so-much-slower-than-julia/51381)

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**Author:** [@TheCedarPrince](https://discourse.julialang.org/u/TheCedarPrince)\
**Replies:** 8\
**Last updated:** [December 7, 2020, 4:55pm UTC](https://discourse.julialang.org/t/why-are-languages-like-python-and-matlab-so-much-slower-than-julia/51381 "2020-12-07T16:55:25Z")

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So I understand why Julia is fast, but why specifically are Python and MATLAB, generally speaking, orders of magnitude slower than Julia when doing similar operations? To give a background on where I am at with my knowl…

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## [Simple conditional loop](https://discourse.julialang.org/t/simple-conditional-loop/51402)

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**Author:** [@darleybarreto](https://discourse.julialang.org/u/darleybarreto)\
**Replies:** 4\
**Last updated:** [December 7, 2020, 4:05pm UTC](https://discourse.julialang.org/t/simple-conditional-loop/51402 "2020-12-07T16:05:37Z")

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Hi folks, I have a question about ifs inside for loops. Suppose I have this function: function c\_cheating(high) total = 0 high \*= 2 for i in 4:4:high total += i end total end Giving @btime c\_cheating(1\_000\_000)…

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## [How to restart CI github checks after adding a commit to JuliLang/julia?](https://discourse.julialang.org/t/how-to-restart-ci-github-checks-after-adding-a-commit-to-julilang-julia/51342)

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**Author:** [@strickek](https://discourse.julialang.org/u/strickek)\
**Replies:** 2\
**Last updated:** [December 7, 2020, 3:24pm UTC](https://discourse.julialang.org/t/how-to-restart-ci-github-checks-after-adding-a-commit-to-julilang-julia/51342 "2020-12-07T15:24:42Z")

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I use Code - OSS with extension “GitHub Pull Requests and Issues”. First, I pushed 3 commits to my Julia fork and then opened a pull request to JuliaLang/julia. Then CI started and 17 checks were positive, except build…

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## [Cannot run basic embedded Julia example](https://discourse.julialang.org/t/cannot-run-basic-embedded-julia-example/51399)

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**Author:** [@circonflexe](https://discourse.julialang.org/u/circonflexe)\
**Replies:** 2\
**Last updated:** [December 7, 2020, 3:13pm UTC](https://discourse.julialang.org/t/cannot-run-basic-embedded-julia-example/51399 "2020-12-07T15:13:10Z")

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I am trying the basic example of embedding Julia in C: file a.c contains #include \<julia.h\> int main(void) { jl\_init(); (void) jl\_eval\_string("print(sqrt(2.))"); return 0; } and the Makefile is also copy-…

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## [How can I compare every values in an array and put the new values in new arry](https://discourse.julialang.org/t/how-can-i-compare-every-values-in-an-array-and-put-the-new-values-in-new-arry/51319)

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**Author:** [@sui](https://discourse.julialang.org/u/sui)\
**Replies:** 12\
**Last updated:** [December 7, 2020, 2:56pm UTC](https://discourse.julialang.org/t/how-can-i-compare-every-values-in-an-array-and-put-the-new-values-in-new-arry/51319 "2020-12-07T14:56:10Z")

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I like to compare array values of that I have. For example, I have a nxm array. I pick A = array\[:,3\] to compare with 0. If it is bigger than 0, the new array will be 1. I have code as A = \[1 2 3; 4 5 6\] a = A\[:,3\] @va…

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## [Edit PNG PLTE](https://discourse.julialang.org/t/edit-png-plte/51305)

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**Author:** [@HugoTrentesaux](https://discourse.julialang.org/u/HugoTrentesaux)\
**Replies:** 6\
**Last updated:** [December 7, 2020, 2:05pm UTC](https://discourse.julialang.org/t/edit-png-plte/51305 "2020-12-07T14:05:05Z")

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The PNG format specifies an optional color palette (PLTE chunk). I want to edit this palette with Julia but do not find a starting point. Is there an existing library which provides this kind of “low level” control over …

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## [Problem with \`@dlsym\` (from the manual) for calling C](https://discourse.julialang.org/t/problem-with-dlsym-from-the-manual-for-calling-c/51403)

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**Author:** [@greg9q](https://discourse.julialang.org/u/greg9q)\
**Replies:** 0\
**Last updated:** [December 7, 2020, 2:04pm UTC](https://discourse.julialang.org/t/problem-with-dlsym-from-the-manual-for-calling-c/51403 "2020-12-07T14:04:40Z")

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The manual’s “Calling C and Fortran Code \> Indirect Calls” section provides the following macro to allow using a non-constant function spec with ccall: macro dlsym(func, lib) z = Ref{Ptr{Cvoid}}(C\_NULL) quote …

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## [Development package dependencies in VSCodium](https://discourse.julialang.org/t/development-package-dependencies-in-vscodium/51181)

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**Author:** [@GerhardHippmann](https://discourse.julialang.org/u/GerhardHippmann)\
**Replies:** 9\
**Last updated:** [December 7, 2020, 12:58pm UTC](https://discourse.julialang.org/t/development-package-dependencies-in-vscodium/51181 "2020-12-07T12:58:37Z")

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I am working on a development package Modia3D which depends on another development package ModiaMath: (@v1.5) pkg\> status Status \`~/.julia/environments/v1.5/Project.toml\` ... \[ee78f7c6\] Makie v0.11.1 \[eff96d63\] Meas…

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## [Types, strange behavior](https://discourse.julialang.org/t/types-strange-behavior/51384)

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**Author:** [@rapasite](https://discourse.julialang.org/u/rapasite)\
**Replies:** 2\
**Last updated:** [December 7, 2020, 10:38am UTC](https://discourse.julialang.org/t/types-strange-behavior/51384 "2020-12-07T10:38:44Z")

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Julia Version 1.5.3 (2020-11-09) Hi, looking at this vector=\[\[1,2\],\[3,\[4,5\]\]\] vector\[1\] typeof(vector\[1\]) julia\> vector=\[\[1,2\],\[3,\[4,5\]\]\] 2-element Array{Array{Any,1},1}: \[1, 2\] \[3, \[4, 5\]\] julia\> vector\[1\] 2-eleme…

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## [Proper use of Threads.Condition](https://discourse.julialang.org/t/proper-use-of-threads-condition/50937)

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**Author:** [@felipenoris](https://discourse.julialang.org/u/felipenoris)\
**Replies:** 2\
**Last updated:** [December 7, 2020, 10:30am UTC](https://discourse.julialang.org/t/proper-use-of-threads-condition/50937 "2020-12-07T10:30:48Z")

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Hi! I’m trying to implement thread-safe event listeners, something that reminds me of Java Event listeners. The idea is that I have many parts of a system that must react to change events in another part of the system. …

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## [Missing attribution](https://discourse.julialang.org/t/missing-attribution/51386)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 2\
**Last updated:** [December 7, 2020, 10:14am UTC](https://discourse.julialang.org/t/missing-attribution/51386 "2020-12-07T10:14:30Z")

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I am looking at Julia packages that deals with missing attribution, i.e. with the problem to use in a dataset the existing information to predict the missing values. I recall I read of a package that does that, but I co…

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## [Nonlinear Objective Function Splatting](https://discourse.julialang.org/t/nonlinear-objective-function-splatting/51251)

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**Author:** [@Flesko](https://discourse.julialang.org/u/Flesko)\
**Replies:** 3\
**Last updated:** [December 7, 2020, 8:30am UTC](https://discourse.julialang.org/t/nonlinear-objective-function-splatting/51251 "2020-12-07T08:30:01Z")

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Hey everyone, I was playing around with nonlinear functions for optimal control problems utilizing JuMP with IPOPT as the solver. I realized convergence problems as soon as I use the splatting operator for passing vecto…

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## [Incremental compilation may be fatally broken for this module](https://discourse.julialang.org/t/incremental-compilation-may-be-fatally-broken-for-this-module/51373)

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**Author:** [@Ravinder\_Ram](https://discourse.julialang.org/u/Ravinder_Ram)\
**Replies:** 1\
**Last updated:** [December 7, 2020, 8:01am UTC](https://discourse.julialang.org/t/incremental-compilation-may-be-fatally-broken-for-this-module/51373 "2020-12-07T08:01:37Z")

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warning why this come? how to remove it

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## [What is a good way to get the n largest elements of a CuArray?](https://discourse.julialang.org/t/what-is-a-good-way-to-get-the-n-largest-elements-of-a-cuarray/51324)

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**Author:** [@pjentsch0](https://discourse.julialang.org/u/pjentsch0)\
**Replies:** 1\
**Last updated:** [December 7, 2020, 7:26am UTC](https://discourse.julialang.org/t/what-is-a-good-way-to-get-the-n-largest-elements-of-a-cuarray/51324 "2020-12-07T07:26:11Z")

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I noticed that partialsort! is not yet defined forCuArray, I don’t need the n largest in any particular order, either. Thank you!

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## [Why Can not My Recursive Function Work?](https://discourse.julialang.org/t/why-can-not-my-recursive-function-work/51378)

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**Author:** [@KyleJT](https://discourse.julialang.org/u/KyleJT)\
**Replies:** 2\
**Last updated:** [December 7, 2020, 7:04am UTC](https://discourse.julialang.org/t/why-can-not-my-recursive-function-work/51378 "2020-12-07T07:04:35Z")

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I want to write a function to add all the arguments, using a recursive function as followed: function add\_Varargs(b...) if length(b) == 1 return b else t=b\[1:end-1\] println(b\[end\]) …

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## [How do I install node.js to use jupyter?](https://discourse.julialang.org/t/how-do-i-install-node-js-to-use-jupyter/51372)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 1\
**Last updated:** [December 7, 2020, 5:28am UTC](https://discourse.julialang.org/t/how-do-i-install-node-js-to-use-jupyter/51372 "2020-12-07T05:28:56Z")

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I need node.js to access extensions in jupyter, as well as to execute certain types of plots in Jupyter or Pluto. How do I add this?

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## [Mixed input layer using Flux gives "ERROR: Mutating arrays is not supported"](https://discourse.julialang.org/t/mixed-input-layer-using-flux-gives-error-mutating-arrays-is-not-supported/41595)

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**Author:** [@rsteckel](https://discourse.julialang.org/u/rsteckel)\
**Replies:** 1\
**Last updated:** [December 7, 2020, 5:08am UTC](https://discourse.julialang.org/t/mixed-input-layer-using-flux-gives-error-mutating-arrays-is-not-supported/41595 "2020-12-07T05:08:45Z")

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I would like to combine input types in the input layer of my Flux model. For example, using the Embedded example layer (found on this forum), I would like to embed the first column of my input data and use a Dense layer…

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## [Gradient of a loss function : struggling to avoid arrays mutation](https://discourse.julialang.org/t/gradient-of-a-loss-function-struggling-to-avoid-arrays-mutation/45593)

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**Author:** [@mothmani](https://discourse.julialang.org/u/mothmani)\
**Replies:** 4\
**Last updated:** [December 7, 2020, 5:02am UTC](https://discourse.julialang.org/t/gradient-of-a-loss-function-struggling-to-avoid-arrays-mutation/45593 "2020-12-07T05:02:51Z")

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Dear all, I’m very new to Julia and mainly interested in its SciML ecosystem. I’m using Julia 1.5 through JuliaPro. My problem deals with fitting parameters driving an ODE (eg the Lotka-Volterra ODE from the SciML tuto…

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## [DIfferentialEquations and GPU](https://discourse.julialang.org/t/differentialequations-and-gpu/21219)

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**Author:** [@fedoroff](https://discourse.julialang.org/u/fedoroff)\
**Replies:** 15\
**Last updated:** [December 7, 2020, 2:44am UTC](https://discourse.julialang.org/t/differentialequations-and-gpu/21219 "2020-12-07T02:44:24Z")

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Hello, According to the following blog post http://www.stochasticlifestyle.com/solving-systems-stochastic-pdes-using-gpus-julia/ it is very easy to turn on GPU parallelism with DifferentialEquations.jl. The only thing o…

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## [Meshfree methods](https://discourse.julialang.org/t/meshfree-methods/51247)

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**Author:** [@FrootLoops](https://discourse.julialang.org/u/FrootLoops)\
**Replies:** 4\
**Last updated:** [December 6, 2020, 7:55pm UTC](https://discourse.julialang.org/t/meshfree-methods/51247 "2020-12-06T19:55:27Z")

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Hi, are there any known packages or modifications for meshfree methods like IGA Galerkin? I cannot find much in the internet. Maybe someone already modified JuAFEM for these kind of applications?

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## [Relationship between variables](https://discourse.julialang.org/t/relationship-between-variables/51272)

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**Author:** [@JohnZ](https://discourse.julialang.org/u/JohnZ)\
**Replies:** 6\
**Last updated:** [December 6, 2020, 7:52pm UTC](https://discourse.julialang.org/t/relationship-between-variables/51272 "2020-12-06T19:52:34Z")

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In an optimisation problem, I have some relationships between variables i.e. they should take same values. I define a dataframe (called Master) that contains all the data and another dataframe (called Relationship) that …

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## [Flux: "cannot broadcast array to have fewer dimensions"](https://discourse.julialang.org/t/flux-cannot-broadcast-array-to-have-fewer-dimensions/39821)

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**Author:** [@dunefox](https://discourse.julialang.org/u/dunefox)\
**Replies:** 4\
**Last updated:** [December 6, 2020, 7:06pm UTC](https://discourse.julialang.org/t/flux-cannot-broadcast-array-to-have-fewer-dimensions/39821 "2020-12-06T19:06:23Z")

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I’m trying to get into Flux and Julia, so I defined two simple models. The first one works, the second one throws an error that I don’t quite understand yet. I’m sure it’s relatively simple to solve, I just don’t see it. …

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## [UndefVarError: P not defined](https://discourse.julialang.org/t/undefvarerror-p-not-defined/51358)

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**Author:** [@Ernesto\_Diaz](https://discourse.julialang.org/u/Ernesto_Diaz)\
**Replies:** 2\
**Last updated:** [December 6, 2020, 6:59pm UTC](https://discourse.julialang.org/t/undefvarerror-p-not-defined/51358 "2020-12-06T18:59:21Z")

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qp=0.6 function Plist(xi,qp) for i=0.001:5:xi push!(P,qp\*i) end return P end P=Plist(240,qp) Previous code return: UndefVarError: P not defined Stracktrace: \[1\]Plist(::Int64, ::Float64) at .\\In\[12\]:5 \[2…

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## [Where pre-compiled package stored in computer?](https://discourse.julialang.org/t/where-pre-compiled-package-stored-in-computer/51355)

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**Author:** [@Ravinder\_Ram](https://discourse.julialang.org/u/Ravinder_Ram)\
**Replies:** 1\
**Last updated:** [December 6, 2020, 6:50pm UTC](https://discourse.julialang.org/t/where-pre-compiled-package-stored-in-computer/51355 "2020-12-06T18:50:57Z")

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whenever pre-compiling happen where compiled package is store can i see it?

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## [\*\* incremental compilation may be fatally broken for this module \*\*](https://discourse.julialang.org/t/incremental-compilation-may-be-fatally-broken-for-this-module/31443)

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**Author:** [@Qiyamah](https://discourse.julialang.org/u/Qiyamah)\
**Replies:** 3\
**Last updated:** [December 6, 2020, 5:58pm UTC](https://discourse.julialang.org/t/incremental-compilation-may-be-fatally-broken-for-this-module/31443 "2020-12-06T17:58:01Z")

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This keeps popping up, when I try to redefine the same macro or function in a module? Is this ok? It tells me that I have overwritten a method, which I did intentionally… Thanks

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## [How confgurate IJulia with python 3.9-64?](https://discourse.julialang.org/t/how-confgurate-ijulia-with-python-3-9-64/51354)

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**Author:** [@HerAdri](https://discourse.julialang.org/u/HerAdri)\
**Replies:** 0\
**Last updated:** [December 6, 2020, 5:57pm UTC](https://discourse.julialang.org/t/how-confgurate-ijulia-with-python-3-9-64/51354 "2020-12-06T17:57:48Z")

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How to configure Ijulia to run correctly with python 3.9-64? Jupyter notebook works fine with python installation C:\\Users\\user\>py -0 Installed Pythons found by py Launcher for Windows -3.9-64 \* C:\\Users\\user\>jupyter …

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