# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1390

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

**Page:** 1391

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## [Pattern for managing thread local storage?](https://discourse.julialang.org/t/pattern-for-managing-thread-local-storage/54023)

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**Author:** [@dmitrip](https://discourse.julialang.org/u/dmitrip)\
**Replies:** 5\
**Last updated:** [May 17, 2021, 1:19pm UTC](https://discourse.julialang.org/t/pattern-for-managing-thread-local-storage/54023 "2021-05-17T13:19:18Z")

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What’s a good pattern for preallocating buffers in a multithreaded setting? I want to avoid allocating new memory whenever I launch a task on a thread. So far I’ve been using the following pattern, which maintains a po…

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## [How install IPOPT with HSL library?](https://discourse.julialang.org/t/how-install-ipopt-with-hsl-library/61303)

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**Author:** [@oscaromar](https://discourse.julialang.org/u/oscaromar)\
**Replies:** 0\
**Last updated:** [May 17, 2021, 12:52pm UTC](https://discourse.julialang.org/t/how-install-ipopt-with-hsl-library/61303 "2021-05-17T12:52:40Z")

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Hey, friends, I don’t know how install IPOPT with HSL library, What is the step by step? Thanks!!!.

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## [FFTW.jl : could not load library "libfftw3"](https://discourse.julialang.org/t/fftw-jl-could-not-load-library-libfftw3/60995)

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**Author:** [@Ashwani\_Rathee](https://discourse.julialang.org/u/Ashwani_Rathee)\
**Replies:** 6\
**Last updated:** [May 17, 2021, 12:28pm UTC](https://discourse.julialang.org/t/fftw-jl-could-not-load-library-libfftw3/60995 "2021-05-17T12:28:25Z")

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I am facing this issue, I have provided the information that has been used to solve this issue. https://github.com/JuliaMath/FFTW.jl/issues/110 It’s local issue to my system and works fine for another contributor there. …

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## [X-axis at center of plot](https://discourse.julialang.org/t/x-axis-at-center-of-plot/24015)

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**Author:** [@rakeshvar](https://discourse.julialang.org/u/rakeshvar)\
**Replies:** 4\
**Last updated:** [May 17, 2021, 12:12pm UTC](https://discourse.julialang.org/t/x-axis-at-center-of-plot/24015 "2021-05-17T12:12:33Z")

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I want the x-axis to be at the center (y=0) but it is coming out at the bottom. using Plots plotly() plot(\[-1, 0, 1\], line=(:stem, 2), m=(:red, 3), xticks=1:3, xmirror=true, yaxis=false)

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## [Instantaneous bandwidth](https://discourse.julialang.org/t/instantaneous-bandwidth/61260)

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**Author:** [@davidwallis](https://discourse.julialang.org/u/davidwallis)\
**Replies:** 4\
**Last updated:** [May 17, 2021, 12:05pm UTC](https://discourse.julialang.org/t/instantaneous-bandwidth/61260 "2021-05-17T12:05:14Z")

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Does anyone have a function to calculate instantaneous bandwidth? Like instbw in Matlab.

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## [Scientific Software Engineer at Cervest (London, UK ± 1 timezone)](https://discourse.julialang.org/t/scientific-software-engineer-at-cervest-london-uk-1-timezone/61298)

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**Author:** [@Libbum](https://discourse.julialang.org/u/Libbum)\
**Replies:** 0\
**Last updated:** [May 17, 2021, 11:56am UTC](https://discourse.julialang.org/t/scientific-software-engineer-at-cervest-london-uk-1-timezone/61298 "2021-05-17T11:56:00Z")

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Our team is looking for a number of Scientific Software Engineers as we release our product to market. Cervest is a certified B corporation, focusing a new market sector: Climate Intelligence. As a Scientific Software E…

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## [Study SH model](https://discourse.julialang.org/t/study-sh-model/61246)

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**Author:** [@Frazze](https://discourse.julialang.org/u/Frazze)\
**Replies:** 6\
**Last updated:** [May 17, 2021, 9:18am UTC](https://discourse.julialang.org/t/study-sh-model/61246 "2021-05-17T09:18:41Z")

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Hi everyone, I’m studying the Swift Hohenberg model with only the linear term of the potential. I see that a tutorial is proposed here (https://rveltz.github.io/BifurcationKit.jl/dev/tutorials2/#Snaking-in-the-2d-Swift-…

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## [Unable to automatically install 'OpenSpecFun' when trying to add 'Symbolics'](https://discourse.julialang.org/t/unable-to-automatically-install-openspecfun-when-trying-to-add-symbolics/60950)

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**Author:** [@Aleksandr\_Mikheev](https://discourse.julialang.org/u/Aleksandr_Mikheev)\
**Replies:** 28\
**Last updated:** [May 17, 2021, 8:49am UTC](https://discourse.julialang.org/t/unable-to-automatically-install-openspecfun-when-trying-to-add-symbolics/60950 "2021-05-17T08:49:14Z")

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The problem is very much related to this one and this one, so I suppose it’s also a good idea to try to poke @giordano. TLDR: When trying to install Symbolics I get the following error: ERROR: Unable to automatically i…

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## [Bridging Slack's #Helpdesk and Discourse (Proposal, feedback welcome!)](https://discourse.julialang.org/t/bridging-slacks-helpdesk-and-discourse-proposal-feedback-welcome/53554)

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**Author:** [@logankilpatrick](https://discourse.julialang.org/u/logankilpatrick)\
**Replies:** 49\
**Last updated:** [May 17, 2021, 8:15am UTC](https://discourse.julialang.org/t/bridging-slacks-helpdesk-and-discourse-proposal-feedback-welcome/53554 "2021-05-17T08:15:59Z")

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Hey all, following up on this proposal: #Helpdesk channel on Slack (proposal to close the channel) and a thread here: I’ve heard a number of people say Julia is not mainstream because it doesn’t have many stackoverflow q…

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## [Flux.params of a matrix implemented as a struct](https://discourse.julialang.org/t/flux-params-of-a-matrix-implemented-as-a-struct/60787)

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**Author:** [@Tomas\_Pevny](https://discourse.julialang.org/u/Tomas_Pevny)\
**Replies:** 11\
**Last updated:** [May 17, 2021, 7:09am UTC](https://discourse.julialang.org/t/flux-params-of-a-matrix-implemented-as-a-struct/60787 "2021-05-17T07:09:16Z")

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Dear All, I have a student who is implementing few algorithms for distributed optimization (training of neural networks) using Flux / Zygote tooling. We have been tracking various sources of inefficiencies and I have f…

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## [Checking for Equality and for Equivalence of Symbolic Expressions](https://discourse.julialang.org/t/checking-for-equality-and-for-equivalence-of-symbolic-expressions/61276)

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**Author:** [@GpuCoder](https://discourse.julialang.org/u/GpuCoder)\
**Replies:** 1\
**Last updated:** [May 17, 2021, 5:50am UTC](https://discourse.julialang.org/t/checking-for-equality-and-for-equivalence-of-symbolic-expressions/61276 "2021-05-17T05:50:51Z")

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I’m having trouble even checking for syntactic equivalence julia\> using Symbolics julia\> @variables t 1-element Vector{Num}: t julia\> (t^2 - t^3) == (t^2 - t^3) (t^2 - (t^3)) == (t^2 - (t^3)) julia\> (t^2 - t^3) === …

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## [Using dependency package in doctests](https://discourse.julialang.org/t/using-dependency-package-in-doctests/61262)

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**Author:** [@baptnz](https://discourse.julialang.org/u/baptnz)\
**Replies:** 6\
**Last updated:** [May 17, 2021, 5:06am UTC](https://discourse.julialang.org/t/using-dependency-package-in-doctests/61262 "2021-05-17T05:06:08Z")

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I’ve created a package and successfully pushed CI-Documenter-generated docs on its github page, but I’m having trouble adding doctests. They currently fail because of a mismatch in the output, and I’m not sure how I shou…

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## [Find Reimann zeta's zeros with SpecialFunctions and Roots](https://discourse.julialang.org/t/find-reimann-zetas-zeros-with-specialfunctions-and-roots/61275)

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**Author:** [@Wei\_Yang](https://discourse.julialang.org/u/Wei_Yang)\
**Replies:** 2\
**Last updated:** [May 17, 2021, 2:11am UTC](https://discourse.julialang.org/t/find-reimann-zetas-zeros-with-specialfunctions-and-roots/61275 "2021-05-17T02:11:13Z")

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To find the zeros of the Reimann \\zeta with real part 1/2, and imaginary part less than 1000 in norm, the following is what I’m using at the moment, using SpecialFunctions using Roots g(x) = abs(zeta(.5 + x\*im)) Z =\[\] …

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## [Can't get the same results at the rocket control tutorial in JuMP](https://discourse.julialang.org/t/cant-get-the-same-results-at-the-rocket-control-tutorial-in-jump/61235)

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**Author:** [@yucho147](https://discourse.julialang.org/u/yucho147)\
**Replies:** 4\
**Last updated:** [May 17, 2021, 12:08am UTC](https://discourse.julialang.org/t/cant-get-the-same-results-at-the-rocket-control-tutorial-in-jump/61235 "2021-05-17T00:08:35Z")

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Hi I am learning how to use the JuMP package. However, I am not getting the same results from the rocket control tutorial. https://jump.dev/JuMP.jl/v0.21.8/tutorials/Nonlinear%20programs/rocket\_control/ In my environm…

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## [Recommended Graphical User Interface with Tabs?](https://discourse.julialang.org/t/recommended-graphical-user-interface-with-tabs/61268)

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**Author:** [@JosephPollacco](https://discourse.julialang.org/u/JosephPollacco)\
**Replies:** 0\
**Last updated:** [May 16, 2021, 11:22pm UTC](https://discourse.julialang.org/t/recommended-graphical-user-interface-with-tabs/61268 "2021-05-16T23:22:44Z")

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For my SoiLWater-ToolBox I am looking for a Graphical User Interface package to input the list of Parameters and Options written in TOML. Since the hydrological models is complex I will need to subdivide the parameters …

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## [How to convert TOML file into a Structure and vice versa?](https://discourse.julialang.org/t/how-to-convert-toml-file-into-a-structure-and-vice-versa/61265)

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**Author:** [@JosephPollacco](https://discourse.julialang.org/u/JosephPollacco)\
**Replies:** 1\
**Last updated:** [May 16, 2021, 11:22pm UTC](https://discourse.julialang.org/t/how-to-convert-toml-file-into-a-structure-and-vice-versa/61265 "2021-05-16T23:22:14Z")

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Hi I have a large SoilWater-ToolBox model and I have got all the input , Parameters, as a mutable struct. In order to create a package I will need to read the parameters outside the model as recommended in previous post …

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## [What recommended format of input parameters/options of a large hydrological model compiled as a Julia Package?](https://discourse.julialang.org/t/what-recommended-format-of-input-parameters-options-of-a-large-hydrological-model-compiled-as-a-julia-package/60561)

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**Author:** [@JosephPollacco](https://discourse.julialang.org/u/JosephPollacco)\
**Replies:** 2\
**Last updated:** [May 16, 2021, 10:59pm UTC](https://discourse.julialang.org/t/what-recommended-format-of-input-parameters-options-of-a-large-hydrological-model-compiled-as-a-julia-package/60561 "2021-05-16T22:59:55Z")

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The question is what format (e.g. .csv, .txt etc…) would you recommend to read Inputs options/ parameters values of a large model https://github.com/manaakiwhenua/SoilWater\_ToolBox.git ? I was informed in Discourse that…

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## [Same code much faster on a Ryzen than on a Xeon?](https://discourse.julialang.org/t/same-code-much-faster-on-a-ryzen-than-on-a-xeon/60534)

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**Author:** [@ederag](https://discourse.julialang.org/u/ederag)\
**Replies:** 10\
**Last updated:** [May 16, 2021, 10:41pm UTC](https://discourse.julialang.org/t/same-code-much-faster-on-a-ryzen-than-on-a-xeon/60534 "2021-05-16T22:41:04Z")

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The time\_evolution ODE kernel below is blazing fast on a Ryzen, and more than 4 times slower on a Xeon. This difference is striking, as usually both machines have similar single thread performances. (more on that below…

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## [Does Mac M1 in multithreads is slower that in single thread?](https://discourse.julialang.org/t/does-mac-m1-in-multithreads-is-slower-that-in-single-thread/61114)

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**Author:** [@BMval](https://discourse.julialang.org/u/BMval)\
**Replies:** 10\
**Last updated:** [May 16, 2021, 6:48pm UTC](https://discourse.julialang.org/t/does-mac-m1-in-multithreads-is-slower-that-in-single-thread/61114 "2021-05-16T18:48:31Z")

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I’ve run a simple code on mac M1 (pro, 8gb ram), Julia is the last version. @Threads for i in 1:1000 rand(1000,1000)/rand(1000,1000) end 1 core = 50 sec 2 core = 62 sec 4 core = 71 sec 8 core = doesn’t work at all. …

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## [\[ANN\] LocalRegistry 0.4](https://discourse.julialang.org/t/ann-localregistry-0-4/61254)

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**Author:** [@GunnarFarneback](https://discourse.julialang.org/u/GunnarFarneback)\
**Replies:** 0\
**Last updated:** [May 16, 2021, 5:57pm UTC](https://discourse.julialang.org/t/ann-localregistry-0-4/61254 "2021-05-16T17:57:05Z")

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LocalRegistry lets you create and maintain local registries for Julia packages. Version 0.4.0 is a breaking release. Breaking Changes The push keyword argument to register now defaults to true. The registry argume…

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## [Accents on greek letters in REPL don't seem to work (Julia 1.6.1)](https://discourse.julialang.org/t/accents-on-greek-letters-in-repl-dont-seem-to-work-julia-1-6-1/61223)

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**Author:** [@ko56](https://discourse.julialang.org/u/ko56)\
**Replies:** 7\
**Last updated:** [May 16, 2021, 4:22pm UTC](https://discourse.julialang.org/t/accents-on-greek-letters-in-repl-dont-seem-to-work-julia-1-6-1/61223 "2021-05-16T16:22:57Z")

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With Julia 1.6.1 on FreeBSD, If I type x\\hatTAB in the REPL, I get the expected, i.e. what LaTeX would produce with \\hat{x}. But if I try \\nuTAB\\hatTAB, the hat appears to the right of \\nu. My recollection is that this…

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## [Gadfly: Color Coding a Simple Bar Chart](https://discourse.julialang.org/t/gadfly-color-coding-a-simple-bar-chart/61211)

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**Author:** [@ben-schulz](https://discourse.julialang.org/u/ben-schulz)\
**Replies:** 2\
**Last updated:** [May 16, 2021, 4:19pm UTC](https://discourse.julialang.org/t/gadfly-color-coding-a-simple-bar-chart/61211 "2021-05-16T16:19:56Z")

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suppose i’m working in a Jupyter notebook with a Julia kernel, and i want to plot some very simple data in a bar chart, to show the proportion of two quantities A and B, like so: # Julia 1.6.1 using Gadfly p = plot(x=\[…

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## [Initiate DataFrame variable with missing values and type Union{Missing, Float64}](https://discourse.julialang.org/t/initiate-dataframe-variable-with-missing-values-and-type-union-missing-float64/61213)

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**Author:** [@klwlevy](https://discourse.julialang.org/u/klwlevy)\
**Replies:** 7\
**Last updated:** [May 16, 2021, 3:18pm UTC](https://discourse.julialang.org/t/initiate-dataframe-variable-with-missing-values-and-type-union-missing-float64/61213 "2021-05-16T15:18:22Z")

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How do I best initiate a new variable to an existing DataFrame, if I want the new variable to contain only missing values? Later I want to assign float values to the new variable. # Initiate a simple dataframe with one …

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## [Constraint declaration generates an error](https://discourse.julialang.org/t/constraint-declaration-generates-an-error/61239)

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**Author:** [@mamo](https://discourse.julialang.org/u/mamo)\
**Replies:** 6\
**Last updated:** [May 16, 2021, 3:16pm UTC](https://discourse.julialang.org/t/constraint-declaration-generates-an-error/61239 "2021-05-16T15:16:34Z")

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Dear all, how to type the constraint below in order to avoid an error. for j in N1 if j\>1 && j\<7 @constraint(vrpm, sum(x\[j,i,k\] for i in N5, k in B if i!=j) -sum(x\[i,j,k\] for i in N4, k in B, if i!=j) == 0) end en…

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## [Max function for two array arguments](https://discourse.julialang.org/t/max-function-for-two-array-arguments/61181)

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**Author:** [@Beliavsky](https://discourse.julialang.org/u/Beliavsky)\
**Replies:** 1\
**Last updated:** [May 15, 2021, 2:36am UTC](https://discourse.julialang.org/t/max-function-for-two-array-arguments/61181 "2021-05-15T02:36:00Z")

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The max function does what I expect for two scalar arguments, but why is max(\[3,5\],\[1,6\]) equal to \[3,5\] and max(\[2,5\],\[3,3\]) equal to \[3,3\]? I can get Fortran-like behavior with max.(\[3,5\],\[1,6\]) which gives \[3,6\].

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## [Julia -J load multiple system images](https://discourse.julialang.org/t/julia-j-load-multiple-system-images/44725)

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**Author:** [@wormholestds9](https://discourse.julialang.org/u/wormholestds9)\
**Replies:** 2\
**Last updated:** [May 16, 2021, 12:21pm UTC](https://discourse.julialang.org/t/julia-j-load-multiple-system-images/44725 "2021-05-16T12:21:16Z")

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I created user-defined system images of some packages. I want to preload packages using -J switch. However, I have a problem. For example, I did the following using three system images. julia -J sysimage1.so -J sysima…

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## [Is it possible to make conditional changes in a TimeArray (TimeSeries) object entries?](https://discourse.julialang.org/t/is-it-possible-to-make-conditional-changes-in-a-timearray-timeseries-object-entries/61231)

<div class="topic-metadata">

**Author:** [@shubh\_b](https://discourse.julialang.org/u/shubh_b)\
**Replies:** 2\
**Last updated:** [May 16, 2021, 12:17pm UTC](https://discourse.julialang.org/t/is-it-possible-to-make-conditional-changes-in-a-timearray-timeseries-object-entries/61231 "2021-05-16T12:17:34Z")

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Here is a TimeArray object ta as using TimeSeries dt = \[Date("2011-12-07"), Date("2012-04-06"), Date("2012-07-07")\] par1 = \[11, 12, 14\] par2 = \[21, 22, 24\] ta = TimeArray((dt = dt, par1 = par1, par2 = par2), timestamp…

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## [Solving System of nonlinear Equations using ModelingToolkit.jl and NonlinearSolve.jl](https://discourse.julialang.org/t/solving-system-of-nonlinear-equations-using-modelingtoolkit-jl-and-nonlinearsolve-jl/59096)

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**Author:** [@wst](https://discourse.julialang.org/u/wst)\
**Replies:** 7\
**Last updated:** [May 16, 2021, 10:14am UTC](https://discourse.julialang.org/t/solving-system-of-nonlinear-equations-using-modelingtoolkit-jl-and-nonlinearsolve-jl/59096 "2021-05-16T10:14:18Z")

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Hey there, I’m fairly new to Julia and this forum (in fact my first post here). About my problem: I’m currently trying to solve a system of 3 nonlinear equations that emerged as the solution of the hanging chain probl…

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## [GPU version of my net got stuck](https://discourse.julialang.org/t/gpu-version-of-my-net-got-stuck/61228)

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**Author:** [@tume](https://discourse.julialang.org/u/tume)\
**Replies:** 0\
**Last updated:** [May 16, 2021, 5:19am UTC](https://discourse.julialang.org/t/gpu-version-of-my-net-got-stuck/61228 "2021-05-16T05:19:49Z")

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I was trying to use a Conv net for the CIFAR-10 data. I was able to train it on CPU, but when I tried to use the GPU on my laptop to do this, it first gave me this warning: Warning: Performing scalar operations on GPU …

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## [Converting filter using "||" condition to subset](https://discourse.julialang.org/t/converting-filter-using-condition-to-subset/61203)

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**Author:** [@kobusherbst](https://discourse.julialang.org/u/kobusherbst)\
**Replies:** 4\
**Last updated:** [May 16, 2021, 4:53am UTC](https://discourse.julialang.org/t/converting-filter-using-condition-to-subset/61203 "2021-05-16T04:53:49Z")

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How do I convert the following code fragment to use subset rather than filter and is there a benefit in doing so for large dataframes? df = DataFrame(a = \[1,2,3,4,6,6\], b=\[1,missing,3,missing,5,missing\], c=\[missing,2,mi…

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