# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1269

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

**Page:** 1270

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## [How to create JuMP expressions without adding them to a model?](https://discourse.julialang.org/t/how-to-create-jump-expressions-without-adding-them-to-a-model/68012)

<div class="topic-metadata">

**Author:** [@ForceBru](https://discourse.julialang.org/u/ForceBru)\
**Replies:** 5\
**Last updated:** [September 11, 2021, 11:56am UTC](https://discourse.julialang.org/t/how-to-create-jump-expressions-without-adding-them-to-a-model/68012 "2021-09-11T11:56:27Z")

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I’m trying to build a GARCH(1, 1) model, and this requires recursively constructing the variance: \\sigma\_t^2 = \\alpha + \\beta \\epsilon\_{t-1}^2 + \\gamma \\sigma\_{t-1}^2 Since the variances are unobserved (only the epsil…

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## [Best way to store subsets of a sample](https://discourse.julialang.org/t/best-way-to-store-subsets-of-a-sample/68018)

<div class="topic-metadata">

**Author:** [@tlorans](https://discourse.julialang.org/u/tlorans)\
**Replies:** 6\
**Last updated:** [September 11, 2021, 11:44am UTC](https://discourse.julialang.org/t/best-way-to-store-subsets-of-a-sample/68018 "2021-09-11T11:44:19Z")

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Hello everyone, I would like to store subsamples from an initial sample of data, perform different operations according to the subsample, and then return outputs in the same order than the initial inputs (\*\* EDIT: with …

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## [LinearInterpolation between two points](https://discourse.julialang.org/t/linearinterpolation-between-two-points/67090)

<div class="topic-metadata">

**Author:** [@ymtoo](https://discourse.julialang.org/u/ymtoo)\
**Replies:** 5\
**Last updated:** [September 11, 2021, 10:22am UTC](https://discourse.julialang.org/t/linearinterpolation-between-two-points/67090 "2021-09-11T10:22:34Z")

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MWE: using Interpolations itp1 = LinearInterpolation(\[1,8600\],\[1,8600\]; extrapolation\_bc=Line()) convert(Float64, itp1(8700)) #-1421.6002606281033 itp2 = LinearInterpolation(\[1,3200,8600\],\[1,3200,8600\]; extrapolation\_…

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## [Request for opinion: less worst my crappy English or text to speak?](https://discourse.julialang.org/t/request-for-opinion-less-worst-my-crappy-english-or-text-to-speak/67829)

<div class="topic-metadata">

**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 8\
**Last updated:** [September 9, 2021, 1:00pm UTC](https://discourse.julialang.org/t/request-for-opinion-less-worst-my-crappy-english-or-text-to-speak/67829 "2021-09-09T13:00:53Z")

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I am producing a blended-learning course on machine learning and Julia, and I would like to ask you if you think that for the average student would be less challenging following the slides with the audio recording of my…

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## [SaferIntegers v3](https://discourse.julialang.org/t/saferintegers-v3/68013)

<div class="topic-metadata">

**Author:** [@JeffreySarnoff](https://discourse.julialang.org/u/JeffreySarnoff)\
**Replies:** 2\
**Last updated:** [September 11, 2021, 2:37am UTC](https://discourse.julialang.org/t/saferintegers-v3/68013 "2021-09-11T02:37:39Z")

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SaferIntegers.jl version 3 exists. The exported abstract types SafeInteger, SafeSigned, SafeUnsigned are now defined as originally intended – Julia’s advancement, the active pursuit of consistant type abstractions, mad…

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## [JuliaCon 2021 Proceedings](https://discourse.julialang.org/t/juliacon-2021-proceedings/55354)

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**Author:** [@carstenbauer](https://discourse.julialang.org/u/carstenbauer)\
**Replies:** 6\
**Last updated:** [September 11, 2021, 5:57am UTC](https://discourse.julialang.org/t/juliacon-2021-proceedings/55354 "2021-09-11T05:57:02Z")

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Hi everyone, as indicated by the recent call for proposals here on discourse we are slowly approaching JuliaCon 2021. On behalf of the editorial board, it is my pleasure to announce that, for the third time in a row, th…

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## [Large-scale least squares with ModelingToolkit.jl?](https://discourse.julialang.org/t/large-scale-least-squares-with-modelingtoolkit-jl/67957)

<div class="topic-metadata">

**Author:** [@twadleigh](https://discourse.julialang.org/u/twadleigh)\
**Replies:** 1\
**Last updated:** [September 11, 2021, 2:15am UTC](https://discourse.julialang.org/t/large-scale-least-squares-with-modelingtoolkit-jl/67957 "2021-09-11T02:15:07Z")

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I’m starting to dig deep into ModelingToolkit.jl with the intention of using it to model a version of the SLAM problem. Ultimately, SLAM problems end up looking like large-scale nonlinear least squares problems. Instead …

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## [GLMakie text plots and LaTeXStrings](https://discourse.julialang.org/t/glmakie-text-plots-and-latexstrings/68014)

<div class="topic-metadata">

**Author:** [@JCQ](https://discourse.julialang.org/u/JCQ)\
**Replies:** 0\
**Last updated:** [September 11, 2021, 2:15am UTC](https://discourse.julialang.org/t/glmakie-text-plots-and-latexstrings/68014 "2021-09-11T02:15:01Z")

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I would like to do interactive LaTeXString text plots. However, updating a LaTeXString Node after the text plot has been created, doesn’t affect the plotted text. Here is a small example: using GLMakie fig = Figure()…

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## [How to parameterize a type on dimensionality of the wrapped array?](https://discourse.julialang.org/t/how-to-parameterize-a-type-on-dimensionality-of-the-wrapped-array/68008)

<div class="topic-metadata">

**Author:** [@tlnagy](https://discourse.julialang.org/u/tlnagy)\
**Replies:** 1\
**Last updated:** [September 11, 2021, 12:16am UTC](https://discourse.julialang.org/t/how-to-parameterize-a-type-on-dimensionality-of-the-wrapped-array/68008 "2021-09-11T00:16:02Z")

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Struggling a bit with parametric types for TiffImages.jl. I want to have two different types of DenseTaggedImage for 2D and 3D images since the ifd variable is a vector for 3D images and 0-dimensional for 2D images. jul…

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## [Julia 1.7 beta 4 doesn't run in termux Android](https://discourse.julialang.org/t/julia-1-7-beta-4-doesnt-run-in-termux-android/67931)

<div class="topic-metadata">

**Author:** [@evad](https://discourse.julialang.org/u/evad)\
**Replies:** 1\
**Last updated:** [September 10, 2021, 10:40pm UTC](https://discourse.julialang.org/t/julia-1-7-beta-4-doesnt-run-in-termux-android/67931 "2021-09-10T22:40:38Z")

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hi, i have installed voidlinux in termux on Android. and up to beta 3, i can download the tarball and unpack in home folder and run ./julia. for beta 4, i did the same, and running ./julia from bin folder says no such …

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## [Package testing with encrypted data; any free services that work like Travis-CI?](https://discourse.julialang.org/t/package-testing-with-encrypted-data-any-free-services-that-work-like-travis-ci/68011)

<div class="topic-metadata">

**Author:** [@joshua\_jones](https://discourse.julialang.org/u/joshua_jones)\
**Replies:** 1\
**Last updated:** [September 10, 2021, 10:34pm UTC](https://discourse.julialang.org/t/package-testing-with-encrypted-data-any-free-services-that-work-like-travis-ci/68011 "2021-09-10T22:34:45Z")

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Long topic line summarizes everything but here are details. To make a long story short, I need a way to test SeisIO.jl that supports encrypted test files. Travis-CI does this, but also started charging $70/month in June…

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## [Creating a performant function using metaprogramming](https://discourse.julialang.org/t/creating-a-performant-function-using-metaprogramming/67671)

<div class="topic-metadata">

**Author:** [@elenev](https://discourse.julialang.org/u/elenev)\
**Replies:** 9\
**Last updated:** [September 10, 2021, 10:06pm UTC](https://discourse.julialang.org/t/creating-a-performant-function-using-metaprogramming/67671 "2021-09-10T22:06:09Z")

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I have a function that constructs a NamedTuple out of a vector of numbers subject to some transformation, something like function vec2tuple(x) ( a = x\[1\], b = 1 + exp(x\[2\]), c = 2 + exp(x\[3\]), d = exp(x\[4\]) / (1 + exp(x…

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## [Powermodels Solver options](https://discourse.julialang.org/t/powermodels-solver-options/68003)

<div class="topic-metadata">

**Author:** [@aaldik](https://discourse.julialang.org/u/aaldik)\
**Replies:** 7\
**Last updated:** [September 10, 2021, 9:54pm UTC](https://discourse.julialang.org/t/powermodels-solver-options/68003 "2021-09-10T21:54:28Z")

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Hello everyone i have a question regarding how to change solver options while using Powermodels.jl. I would appreciate your help in this regard.

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## [Namespace with lexical access](https://discourse.julialang.org/t/namespace-with-lexical-access/68010)

<div class="topic-metadata">

**Author:** [@jzr](https://discourse.julialang.org/u/jzr)\
**Replies:** 1\
**Last updated:** [September 10, 2021, 9:46pm UTC](https://discourse.julialang.org/t/namespace-with-lexical-access/68010 "2021-09-10T21:46:50Z")

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I often want to use a namespace for calculating stuff like this FOO = 1 namespace A x = FOO + 1 end This is almost like a module except modules need to import names from the enclosing lexical module, which can be inco…

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## [Print all the values a function was called with to stdout (equivalent of python's \`inspect.getcallargs\`)?](https://discourse.julialang.org/t/print-all-the-values-a-function-was-called-with-to-stdout-equivalent-of-pythons-inspect-getcallargs/67988)

<div class="topic-metadata">

**Author:** [@mkarikom](https://discourse.julialang.org/u/mkarikom)\
**Replies:** 1\
**Last updated:** [September 10, 2021, 7:47pm UTC](https://discourse.julialang.org/t/print-all-the-values-a-function-was-called-with-to-stdout-equivalent-of-pythons-inspect-getcallargs/67988 "2021-09-10T19:47:15Z")

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Looking for a lightweight way to print all of the following: \<arg/keyword-arg\> .=\> \<value that was passed or default\> here is what the equivalent would be in python: print(getcallargs(show\_params, \*args, \*\*kwargs))

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## [Why do I get a key error when using a created symbol?](https://discourse.julialang.org/t/why-do-i-get-a-key-error-when-using-a-created-symbol/68001)

<div class="topic-metadata">

**Author:** [@cybervigilante](https://discourse.julialang.org/u/cybervigilante)\
**Replies:** 1\
**Last updated:** [September 10, 2021, 7:30pm UTC](https://discourse.julialang.org/t/why-do-i-get-a-key-error-when-using-a-created-symbol/68001 "2021-09-10T19:30:34Z")

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I thought it would be handy to create Symbols, and that worked, but why do I get a key error when I try to use them in a Dict? fim = \[Symbol(n) for n in "abcdef"\] 6-element Vector{Symbol}: :a :b :c :d :e :f d = …

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## [Finding Pythagorean triples](https://discourse.julialang.org/t/finding-pythagorean-triples/67954)

<div class="topic-metadata">

**Author:** [@cybervigilante](https://discourse.julialang.org/u/cybervigilante)\
**Replies:** 9\
**Last updated:** [September 10, 2021, 7:28pm UTC](https://discourse.julialang.org/t/finding-pythagorean-triples/67954 "2021-09-10T19:28:11Z")

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I was writing a small routine to find Pythagorean triples. Getting an x^2 + y^2 list was easy, but testing for sqrt of that gives me a Float rather than an Int, and floats are subject to binary error so I might not have …

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## [Two nearly identical loops — why is one faster?](https://discourse.julialang.org/t/two-nearly-identical-loops-why-is-one-faster/67998)

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**Author:** [@stevengj](https://discourse.julialang.org/u/stevengj)\
**Replies:** 2\
**Last updated:** [September 10, 2021, 7:03pm UTC](https://discourse.julialang.org/t/two-nearly-identical-loops-why-is-one-faster/67998 "2021-09-10T19:03:49Z")

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The following two functions both evaluate Chebyshev polynomials, using slightly different recurrences that nevertheless require nearly the same number of operations, both are type-stable with 0 allocations, and yet one o…

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## [Obtaining a Julia \`Image\` from Luxor.jl](https://discourse.julialang.org/t/obtaining-a-julia-image-from-luxor-jl/67992)

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**Author:** [@OvidiusCicero](https://discourse.julialang.org/u/OvidiusCicero)\
**Replies:** 2\
**Last updated:** [September 10, 2021, 6:49pm UTC](https://discourse.julialang.org/t/obtaining-a-julia-image-from-luxor-jl/67992 "2021-09-10T18:49:31Z")

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At the moment I draw an Image with Luxor and load it back into an Image with using Luxor, Images, FileIO d = Luxor.Drawing(width, height, "temp.png") … Luxor.finish() load("temp.png") Is there a way to get the image ba…

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## [Confused about build\_function](https://discourse.julialang.org/t/confused-about-build-function/67946)

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**Author:** [@gzheng](https://discourse.julialang.org/u/gzheng)\
**Replies:** 6\
**Last updated:** [September 10, 2021, 5:55pm UTC](https://discourse.julialang.org/t/confused-about-build-function/67946 "2021-09-10T17:55:01Z")

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I wanted to do a very basic application of build\_function to test out modelingtoolkit.jl, but ran into issues. using ModelingToolkit @parameters a b @variables x y = x^2 z = x + a f\_y = build\_function(y, x) # This wo…

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## [Distributed sparse matrix assembly](https://discourse.julialang.org/t/distributed-sparse-matrix-assembly/67986)

<div class="topic-metadata">

**Author:** [@fgerick](https://discourse.julialang.org/u/fgerick)\
**Replies:** 7\
**Last updated:** [September 10, 2021, 5:04pm UTC](https://discourse.julialang.org/t/distributed-sparse-matrix-assembly/67986 "2021-09-10T17:04:40Z")

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Hi, I’m having trouble understanding how Distributed works. I guess it’s something trivial for someone, but I’m no expert on this. I assume it is a mistake related to the movement of data, but I don’t see how to solve t…

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## [Wondering Why the Variable is Not Used](https://discourse.julialang.org/t/wondering-why-the-variable-is-not-used/67731)

<div class="topic-metadata">

**Author:** [@Edward\_Kong](https://discourse.julialang.org/u/Edward_Kong)\
**Replies:** 15\
**Last updated:** [September 10, 2021, 4:08pm UTC](https://discourse.julialang.org/t/wondering-why-the-variable-is-not-used/67731 "2021-09-10T16:08:01Z")

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I wonder why the grey variable names exist. As I concerned, I think it should have been used.

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## [Fitting a observed value to a Binomial Distribution Turing](https://discourse.julialang.org/t/fitting-a-observed-value-to-a-binomial-distribution-turing/66619)

<div class="topic-metadata">

**Author:** [@jonathan\_skai](https://discourse.julialang.org/u/jonathan_skai)\
**Replies:** 3\
**Last updated:** [September 10, 2021, 4:04pm UTC](https://discourse.julialang.org/t/fitting-a-observed-value-to-a-binomial-distribution-turing/66619 "2021-09-10T16:04:57Z")

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I am new to Turing and trying to learn it by trying to replicate the Chapters from the book :- https://github.com/CamDavidsonPilon/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers . Here is my problem (from Ch…

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## [Android and iOS apps accessing data in juliadb](https://discourse.julialang.org/t/android-and-ios-apps-accessing-data-in-juliadb/21882)

<div class="topic-metadata">

**Author:** [@eagles051387](https://discourse.julialang.org/u/eagles051387)\
**Replies:** 1\
**Last updated:** [September 10, 2021, 3:44pm UTC](https://discourse.julialang.org/t/android-and-ios-apps-accessing-data-in-juliadb/21882 "2021-09-10T15:44:22Z")

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Hi Guys, How can I have an android or iOS app speak to julia or is it best to pass the data onto an RDBMS and have the mobile apps speak to the RDBMS instead

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## [How to parallelize something which allocates a lot?](https://discourse.julialang.org/t/how-to-parallelize-something-which-allocates-a-lot/67853)

<div class="topic-metadata">

**Author:** [@SteffenPL](https://discourse.julialang.org/u/SteffenPL)\
**Replies:** 10\
**Last updated:** [September 10, 2021, 3:42pm UTC](https://discourse.julialang.org/t/how-to-parallelize-something-which-allocates-a-lot/67853 "2021-09-10T15:42:33Z")

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I have a simulation, which needs around 50MB of RAM and 1 second to finish (lets call it simulate(p)). My problem is that I have to run these simulations around 500 times, which suddenly leads to a slowdown (maybe) due …

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## [Looking for a few talented Julia Developers- Remote Work](https://discourse.julialang.org/t/looking-for-a-few-talented-julia-developers-remote-work/67989)

<div class="topic-metadata">

**Author:** [@juliafanatics](https://discourse.julialang.org/u/juliafanatics)\
**Replies:** 0\
**Last updated:** [September 10, 2021, 3:26pm UTC](https://discourse.julialang.org/t/looking-for-a-few-talented-julia-developers-remote-work/67989 "2021-09-10T15:26:40Z")

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Julia Programmers- Remote Work This is your opportunity to be part of a growing team that loves and breathes Julia! We are an established software development company that has been using Julia for many years. We are c…

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## [Trouble using Distributed in Juno with non-default environment](https://discourse.julialang.org/t/trouble-using-distributed-in-juno-with-non-default-environment/49603)

<div class="topic-metadata">

**Author:** [@yha](https://discourse.julialang.org/u/yha)\
**Replies:** 2\
**Last updated:** [September 10, 2021, 3:08pm UTC](https://discourse.julialang.org/t/trouble-using-distributed-in-juno-with-non-default-environment/49603 "2021-09-10T15:08:53Z")

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I’m struggling to use Distributed inside Juno without running into what seem to be pre-compilation race conditions. I can’t get @everywhere using to work (for some packages) outside the default environment, though it wor…

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## [If, elseif, else vs Case When](https://discourse.julialang.org/t/if-elseif-else-vs-case-when/67978)

<div class="topic-metadata">

**Author:** [@Billpete002](https://discourse.julialang.org/u/Billpete002)\
**Replies:** 5\
**Last updated:** [September 10, 2021, 2:37pm UTC](https://discourse.julialang.org/t/if-elseif-else-vs-case-when/67978 "2021-09-10T14:37:45Z")

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I was trying to get a multiple conditional statement running and I keep hitting an error. df1 = @chain df begin @transform(:Business\_Type = if :Business\_Type .== "Corporate Travel Department (CTD)" …

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## [Need theory on why SVG Output is no longer auto-zooming in VSCode plots pane](https://discourse.julialang.org/t/need-theory-on-why-svg-output-is-no-longer-auto-zooming-in-vscode-plots-pane/67985)

<div class="topic-metadata">

**Author:** [@Adam\_Fleischhacker](https://discourse.julialang.org/u/Adam_Fleischhacker)\
**Replies:** 3\
**Last updated:** [September 10, 2021, 2:28pm UTC](https://discourse.julialang.org/t/need-theory-on-why-svg-output-is-no-longer-auto-zooming-in-vscode-plots-pane/67985 "2021-09-10T14:28:28Z")

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My SVG output from CairoMakie used to auto-zoom perfectly on the image. Now I am getting a non-zoomed output by default with weird text saying data:image/svg+xml. Here is a pic of the default output: I would rather…

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## [Gtk.jl clear canvas on key event](https://discourse.julialang.org/t/gtk-jl-clear-canvas-on-key-event/67757)

<div class="topic-metadata">

**Author:** [@htmj](https://discourse.julialang.org/u/htmj)\
**Replies:** 2\
**Last updated:** [September 10, 2021, 2:18pm UTC](https://discourse.julialang.org/t/gtk-jl-clear-canvas-on-key-event/67757 "2021-09-10T14:18:48Z")

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Hi! I’m trying to make a simple drawing app, and i want to clear the canvas when space is pressed. I understood from this discussion Resetting the canvas within Cairo.jl and Gtk.jl for an image selection viewing gui that…

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