# General Usage

**URL:** https://discourse.julialang.org/c/usage/6.md?page=510

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**Page:** 511

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## [Undesired memory allocation during interpolation](https://discourse.julialang.org/t/undesired-memory-allocation-during-interpolation/72713)

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**Author:** [@Gravlax](https://discourse.julialang.org/u/Gravlax)\
**Replies:** 33\
**Last updated:** [December 8, 2021, 6:56pm UTC](https://discourse.julialang.org/t/undesired-memory-allocation-during-interpolation/72713 "2021-12-08T18:56:26Z")

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Dear all, I am writing a script that will require many interpolations in a row (10000s). I am trying to make it such that no allocation is made during the successive calls to Itp1D (). Therefore I’ve allocated all requ…

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## [Using MKL in 1.7](https://discourse.julialang.org/t/using-mkl-in-1-7/72398)

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**Author:** [@ctkelley](https://discourse.julialang.org/u/ctkelley)\
**Replies:** 11\
**Last updated:** [December 8, 2021, 6:44pm UTC](https://discourse.julialang.org/t/using-mkl-in-1-7/72398 "2021-12-08T18:44:29Z")

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My understanding is that all you need to do is type using MKL in the REPL and BLAS trampoline will take care of the rest. When I do that I see no difference in performance. What should I be doing? I’m on an Intel Mac …

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## [Pairwise iterator](https://discourse.julialang.org/t/pairwise-iterator/63927)

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**Author:** [@owiecc](https://discourse.julialang.org/u/owiecc)\
**Replies:** 5\
**Last updated:** [December 8, 2021, 5:43pm UTC](https://discourse.julialang.org/t/pairwise-iterator/63927 "2021-12-08T17:43:28Z")

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Imagine you have a vector \[1,2,3,4\] and would like to have easily access adjacent elements: (1,2) (2,3) (3,4) I used to do it with a for loop and then just access the i-th and i+1-th element while looping over 1 to l…

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## [Packagecompiler.jl installation issue on windows with julia 1.2](https://discourse.julialang.org/t/packagecompiler-jl-installation-issue-on-windows-with-julia-1-2/72779)

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**Author:** [@manoj.centura](https://discourse.julialang.org/u/manoj.centura)\
**Replies:** 3\
**Last updated:** [December 8, 2021, 4:53pm UTC](https://discourse.julialang.org/t/packagecompiler-jl-installation-issue-on-windows-with-julia-1-2/72779 "2021-12-08T16:53:56Z")

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hi All, I am trying to install PackageCompiler.jl with julia 1.2 on windows. getting the below error Building LibCURL ────────→ \`C:\\Users\\manojkumar.ram\\.julia\\packages\\LibCURL\\lWJxD\\deps\\build.log\` Building WinRPM…

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## [Problems in 1.6.4 with IJulia. Downgrade to 1.6.3?](https://discourse.julialang.org/t/problems-in-1-6-4-with-ijulia-downgrade-to-1-6-3/72129)

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**Author:** [@ctkelley](https://discourse.julialang.org/u/ctkelley)\
**Replies:** 17\
**Last updated:** [December 8, 2021, 3:57pm UTC](https://discourse.julialang.org/t/problems-in-1-6-4-with-ijulia-downgrade-to-1-6-3/72129 "2021-12-08T15:57:24Z")

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I am having a problem with IJulia throwing StackOverflowError: in 1.6.4. I am pretty sure that I was having no problem in 1.6.3 and have tested the notebook in 1.6.1 with no problems. Is there any way I can get 1.6.3 to…

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## [Handling project specific variables for a library?](https://discourse.julialang.org/t/handling-project-specific-variables-for-a-library/72705)

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**Author:** [@volkerkarle](https://discourse.julialang.org/u/volkerkarle)\
**Replies:** 1\
**Last updated:** [December 8, 2021, 3:08pm UTC](https://discourse.julialang.org/t/handling-project-specific-variables-for-a-library/72705 "2021-12-08T15:08:53Z")

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Dear community, I am working on a numerical library. The following is only some style aspect, so nothing crucial: There are some variables/ routines which are needed for every function, and I wonder how I could simplify…

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## [Find the intersection of elements of powerset one by one](https://discourse.julialang.org/t/find-the-intersection-of-elements-of-powerset-one-by-one/72763)

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**Author:** [@XLVII](https://discourse.julialang.org/u/XLVII)\
**Replies:** 3\
**Last updated:** [December 8, 2021, 3:02pm UTC](https://discourse.julialang.org/t/find-the-intersection-of-elements-of-powerset-one-by-one/72763 "2021-12-08T15:02:57Z")

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Let S = { trigon, tetragon , pentagon , ... ,... } is a set of polygons How to calculate intersection of subsets of (every element actually) Powerset(S) Powerset(S) =\[ {} , {trigon} , {tetragon} , {pentagon} , {trigon,…

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## [Interruptible routine: the routine does not receive SIGINT if there is no gap in the loop](https://discourse.julialang.org/t/interruptible-routine-the-routine-does-not-receive-sigint-if-there-is-no-gap-in-the-loop/72746)

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**Author:** [@Bossax](https://discourse.julialang.org/u/Bossax)\
**Replies:** 5\
**Last updated:** [December 8, 2021, 1:30pm UTC](https://discourse.julialang.org/t/interruptible-routine-the-routine-does-not-receive-sigint-if-there-is-no-gap-in-the-loop/72746 "2021-12-08T13:30:05Z")

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Hi all, I am learning to create an Interruptible routine for my camera sensor. My goal is to run an image acquisition routine on a remote process so that the local process can receive command from the user to perform ot…

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## [Stackoverflow using backslash operator in Juno](https://discourse.julialang.org/t/stackoverflow-using-backslash-operator-in-juno/72755)

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**Author:** [@sebastianmyrback](https://discourse.julialang.org/u/sebastianmyrback)\
**Replies:** 1\
**Last updated:** [December 8, 2021, 9:39am UTC](https://discourse.julialang.org/t/stackoverflow-using-backslash-operator-in-juno/72755 "2021-12-08T09:39:13Z")

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Hi, I am using Juno for Julia 1.7 on macOS. I have a problem of receiving a Stackoverflow error when running a Julia script, which does not give an error when I type it in the REPL in Atom, nor the Julia terminal. I try …

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## [Has Anyone Interfaced Julia with Haskell?](https://discourse.julialang.org/t/has-anyone-interfaced-julia-with-haskell/72751)

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**Author:** [@TheCedarPrince](https://discourse.julialang.org/u/TheCedarPrince)\
**Replies:** 0\
**Last updated:** [December 8, 2021, 8:03am UTC](https://discourse.julialang.org/t/has-anyone-interfaced-julia-with-haskell/72751 "2021-12-08T08:03:10Z")

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Hi all, Out of curiosity, has anyone interfaced Julia with a Haskell instance? I am curious about bridging the two languages and was curious if anyone had attempted this before. Thanks! ~ tcp :deciduous\_tree:

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## [How compare two vectors in conditional](https://discourse.julialang.org/t/how-compare-two-vectors-in-conditional/72747)

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**Author:** [@Sbeltranj](https://discourse.julialang.org/u/Sbeltranj)\
**Replies:** 3\
**Last updated:** [December 8, 2021, 6:39am UTC](https://discourse.julialang.org/t/how-compare-two-vectors-in-conditional/72747 "2021-12-08T06:39:18Z")

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Hi, I want to make the comparison between two vectors, it must have the condition that a \< 0 and b \< 0, this is my code: a = vec(rand(8,1)) b = vec(rand(8,1)) if a .\< 0 && b .\< 0 #compare two vector a = 0 b = 1…

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## [Error: KeyError: key packagename \[uuid\] not found](https://discourse.julialang.org/t/error-keyerror-key-packagename-uuid-not-found/72658)

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**Author:** [@Jake](https://discourse.julialang.org/u/Jake)\
**Replies:** 1\
**Last updated:** [December 7, 2021, 8:42pm UTC](https://discourse.julialang.org/t/error-keyerror-key-packagename-uuid-not-found/72658 "2021-12-07T20:42:42Z")

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I have created a package in the ~.julia\\dev directory. I used PkgTemplates for its creation. The package seems to have a correct project.toml and manifest.toml. The package name was not found in ~.julia\\environments\\v…

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## [Reducing (time spent in) garbage collection](https://discourse.julialang.org/t/reducing-time-spent-in-garbage-collection/72715)

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**Author:** [@sstroemer](https://discourse.julialang.org/u/sstroemer)\
**Replies:** 2\
**Last updated:** [December 7, 2021, 4:34pm UTC](https://discourse.julialang.org/t/reducing-time-spent-in-garbage-collection/72715 "2021-12-07T16:34:20Z")

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I’m using the code posted below to create a simple JuMP model with variable size. Depending on the size and the way I construct the problem this induces somewhere between 20-80% of the total time spent in garbage collect…

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## [Best practice for avoiding line break bugs in long expressions](https://discourse.julialang.org/t/best-practice-for-avoiding-line-break-bugs-in-long-expressions/7475)

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**Author:** [@NickNack](https://discourse.julialang.org/u/NickNack)\
**Replies:** 26\
**Last updated:** [December 7, 2021, 4:22pm UTC](https://discourse.julialang.org/t/best-practice-for-avoiding-line-break-bugs-in-long-expressions/7475 "2021-12-07T16:22:30Z")

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I had a very frustrating debugging session yesterday. My code was running without errors but producing incorrect results. It took at least two hours for me to find this problem: x = a + really \* long + + (and + comp…

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## [Update range with the same number of samples, Makie](https://discourse.julialang.org/t/update-range-with-the-same-number-of-samples-makie/72719)

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**Author:** [@lazarusA](https://discourse.julialang.org/u/lazarusA)\
**Replies:** 1\
**Last updated:** [December 7, 2021, 3:58pm UTC](https://discourse.julialang.org/t/update-range-with-the-same-number-of-samples-makie/72719 "2021-12-07T15:58:49Z")

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How to use the information from ax.finallimits\[\] to update my plot to a new range in x and y when I do zoom in or zoom out in my plot? The catch is that the number of samples needs to remain the same. using GLMakie fig …

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## [Plot in Pluto.jl made with the plotly backend has a lot of wasted white space](https://discourse.julialang.org/t/plot-in-pluto-jl-made-with-the-plotly-backend-has-a-lot-of-wasted-white-space/72681)

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**Author:** [@ultrapoci](https://discourse.julialang.org/u/ultrapoci)\
**Replies:** 11\
**Last updated:** [December 7, 2021, 2:02pm UTC](https://discourse.julialang.org/t/plot-in-pluto-jl-made-with-the-plotly-backend-has-a-lot-of-wasted-white-space/72681 "2021-12-07T14:02:12Z")

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I’ve made a simple plot in Pluto.jl with the plotly() backend, but as you can see from the picture, it has a lot of white space on its left. The cells in Pluto are already pretty small, and this makes the plot even small…

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## [Workflow question: loading models for simulation](https://discourse.julialang.org/t/workflow-question-loading-models-for-simulation/72709)

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**Author:** [@ivborissov](https://discourse.julialang.org/u/ivborissov)\
**Replies:** 0\
**Last updated:** [December 7, 2021, 12:58pm UTC](https://discourse.julialang.org/t/workflow-question-loading-models-for-simulation/72709 "2021-12-07T12:58:50Z")

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Hi, My question is related to optimization of the following workflow. I have a package MySimPkg to simulate ODE-based models and I load those models (currently julia .jl files) to run simulations. Each model.jl looks l…

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## [VS Code + stackoverflowerror](https://discourse.julialang.org/t/vs-code-stackoverflowerror/72704)

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**Author:** [@RJDennis](https://discourse.julialang.org/u/RJDennis)\
**Replies:** 3\
**Last updated:** [December 7, 2021, 10:58am UTC](https://discourse.julialang.org/t/vs-code-stackoverflowerror/72704 "2021-12-07T10:58:31Z")

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Is anyone else getting the following error? I’m running Windows and I get the error for both 1.7 and 1.6.4 when running the following in VS Code (but not when it is run directly in the REPL) function test() a = r…

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## [Dbscan clustering with distance matrix](https://discourse.julialang.org/t/dbscan-clustering-with-distance-matrix/72700)

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**Author:** [@frits45](https://discourse.julialang.org/u/frits45)\
**Replies:** 6\
**Last updated:** [December 7, 2021, 11:51am UTC](https://discourse.julialang.org/t/dbscan-clustering-with-distance-matrix/72700 "2021-12-07T11:51:37Z")

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Hello, I need to cluster “objects” that are not points in space, but I can calculate a distance between them. The documentation says: There are two implementations of DBSCAN algorithm in this package (both provided by…

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## [StackOverflowError with CSV.File when using HybridArrays and Symbolics in 1.7](https://discourse.julialang.org/t/stackoverflowerror-with-csv-file-when-using-hybridarrays-and-symbolics-in-1-7/72652)

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**Author:** [@judober](https://discourse.julialang.org/u/judober)\
**Replies:** 6\
**Last updated:** [December 7, 2021, 6:51am UTC](https://discourse.julialang.org/t/stackoverflowerror-with-csv-file-when-using-hybridarrays-and-symbolics-in-1-7/72652 "2021-12-07T06:51:00Z")

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Hello everyone, I’m getting StackOverflowError() when runing the folowing code in Julia 1.7: using CSV, Symbolics, HybridArrays function test1() CSV.File("test.dat"; delim = "; ", types = Float64) end test1() te…

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## [Alternative to computation in a loop for distances for fast performance](https://discourse.julialang.org/t/alternative-to-computation-in-a-loop-for-distances-for-fast-performance/72642)

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**Author:** [@nagda95](https://discourse.julialang.org/u/nagda95)\
**Replies:** 9\
**Last updated:** [December 7, 2021, 2:17am UTC](https://discourse.julialang.org/t/alternative-to-computation-in-a-loop-for-distances-for-fast-performance/72642 "2021-12-07T02:17:38Z")

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Hello Everyone, I want to compute the distance (SqEuclidean) of a new point (newP) from the existing neighboring points in a specific order. I have the following code: newP=\[x y z\] for i in eachindex(order) Dist\[i\]=su…

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## [How to select rows of a dataframe?](https://discourse.julialang.org/t/how-to-select-rows-of-a-dataframe/72682)

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**Author:** [@corny85](https://discourse.julialang.org/u/corny85)\
**Replies:** 3\
**Last updated:** [December 6, 2021, 10:06pm UTC](https://discourse.julialang.org/t/how-to-select-rows-of-a-dataframe/72682 "2021-12-06T22:06:11Z")

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Hello, I have a dataframe df with 5 rows and a vector of vectors v=\[\[3\],\[5\],\[1,2\],\[4\]\]. I want to create a new dataframe dg with rows indexes sorted in order of v: the 1st row of dg is the 3rd row of df the 2nd row …

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## [How to insert a new vector in a vector of vectors](https://discourse.julialang.org/t/how-to-insert-a-new-vector-in-a-vector-of-vectors/72678)

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**Author:** [@corny85](https://discourse.julialang.org/u/corny85)\
**Replies:** 3\
**Last updated:** [December 6, 2021, 8:39pm UTC](https://discourse.julialang.org/t/how-to-insert-a-new-vector-in-a-vector-of-vectors/72678 "2021-12-06T20:39:11Z")

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Hello, I’m beginning with Julia. Here is my problem: i have a vector of vectors that i fill up inside a loop under some conditions. At starting, i have v=\[\[1\]\]. Then with push! and pushfirst!, i fill up v. For examp…

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## [Increase perfomance for Gillespie Algorithm](https://discourse.julialang.org/t/increase-perfomance-for-gillespie-algorithm/72369)

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**Author:** [@Luis](https://discourse.julialang.org/u/Luis)\
**Replies:** 19\
**Last updated:** [December 6, 2021, 7:56pm UTC](https://discourse.julialang.org/t/increase-perfomance-for-gillespie-algorithm/72369 "2021-12-06T19:56:29Z")

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I am relatively new to Julia and trying to implement a version of Gillespies Algorithm that can be used in population genetics. I tried really hard to make it as fast and light weighted as possible, incorporating most o…

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## [Strange warning on PyPlot for 1.7.0 "vendor() is depreciated ..."](https://discourse.julialang.org/t/strange-warning-on-pyplot-for-1-7-0-vendor-is-depreciated/72675)

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**Author:** [@ctkelley](https://discourse.julialang.org/u/ctkelley)\
**Replies:** 2\
**Last updated:** [December 6, 2021, 7:17pm UTC](https://discourse.julialang.org/t/strange-warning-on-pyplot-for-1-7-0-vendor-is-depreciated/72675 "2021-12-06T19:17:31Z")

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I’m using 1.7.0 on my Intel machines now with the MKL Blas and happily avoiding the OpenBlas problem. I got this message from PyPlot the first time I call it from 1.7.0 in a new REPL session but not for calls after that …

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## [On writing modules using functions from other packages](https://discourse.julialang.org/t/on-writing-modules-using-functions-from-other-packages/72602)

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**Author:** [@BrunoVasco](https://discourse.julialang.org/u/BrunoVasco)\
**Replies:** 2\
**Last updated:** [December 5, 2021, 10:37am UTC](https://discourse.julialang.org/t/on-writing-modules-using-functions-from-other-packages/72602 "2021-12-05T10:37:16Z")

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I’m trying to write a module for data visualization that uses the function Gray from the package Images.jl. From what I gather, this should have been a matter of creating my module and “calling” the other package and its…

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## [Using (Web) packages together is much slower, e.g. 0.2 sec + 0.7 sec = 7.8 sec](https://discourse.julialang.org/t/using-web-packages-together-is-much-slower-e-g-0-2-sec-0-7-sec-7-8-sec/72075)

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**Author:** [@Palli](https://discourse.julialang.org/u/Palli)\
**Replies:** 4\
**Last updated:** [December 6, 2021, 3:50pm UTC](https://discourse.julialang.org/t/using-web-packages-together-is-much-slower-e-g-0-2-sec-0-7-sec-7-8-sec/72075 "2021-12-06T15:50:52Z")

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I’ll first say, the composability of Julia packages is (otherwise) excellent. I can e.g. use these two packages together, and these are the times, if loading individually (and exiting in-between): julia\> @time using We…

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## [Package compiler fails when using Julia 1.7](https://discourse.julialang.org/t/package-compiler-fails-when-using-julia-1-7/72421)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 1\
**Last updated:** [December 3, 2021, 12:39am UTC](https://discourse.julialang.org/t/package-compiler-fails-when-using-julia-1-7/72421 "2021-12-03T00:39:46Z")

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I have a package and a script that creates a new system image. It works fine with Julia 1.6.4, but fails with Julia 1.7. I tried both on Ubuntu 18.04 and 20.04. Strange error messages: ⠙ \[04m:36s\] PackageCompiler: compi…

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## [Most Efficient Way to Update and Array/Variable?](https://discourse.julialang.org/t/most-efficient-way-to-update-and-array-variable/72606)

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**Author:** [@marianoarnaiz](https://discourse.julialang.org/u/marianoarnaiz)\
**Replies:** 8\
**Last updated:** [December 6, 2021, 10:53am UTC](https://discourse.julialang.org/t/most-efficient-way-to-update-and-array-variable/72606 "2021-12-06T10:53:22Z")

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Hi all! First of all, thanks for reading. I am trying to enhance the performance of this function and I wonder if there is a more Julian way to write it in order to make it faster! I have 4 variables that I update ins…

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## [HoJ bot : Heroku Memory quota exceed](https://discourse.julialang.org/t/hoj-bot-heroku-memory-quota-exceed/61194)

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**Author:** [@Ashwani\_Rathee](https://discourse.julialang.org/u/Ashwani_Rathee)\
**Replies:** 5\
**Last updated:** [December 6, 2021, 8:27am UTC](https://discourse.julialang.org/t/hoj-bot-heroku-memory-quota-exceed/61194 "2021-12-06T08:27:48Z")

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Fellow Julians : I was trying to put HoJ(Humans of Julia) bot on heroku, but memory quota exceeded issue keeps arising. Yeah, atleast with the free tier that’s the case. Though I think in general it would be awesome to…

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