# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=347

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**Page:** 348

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## [Loss of precision when plotting large floats in Makie](https://discourse.julialang.org/t/loss-of-precision-when-plotting-large-floats-in-makie/65802)

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**Author:** [@MaltheSR](https://discourse.julialang.org/u/MaltheSR)\
**Replies:** 3\
**Last updated:** [August 4, 2021, 3:05pm UTC](https://discourse.julialang.org/t/loss-of-precision-when-plotting-large-floats-in-makie/65802 "2021-08-04T15:05:53Z")

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I’m new to Julia and have been toying around with Makie to move some of my plotting from R/ggplot to Julia/Makie, which has been a pleasure so far. However, I’ve been having an issue which I believe to be illustrated by …

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## [Least squares fitting that accounts for covariance matrix of all input parameters](https://discourse.julialang.org/t/least-squares-fitting-that-accounts-for-covariance-matrix-of-all-input-parameters/64775)

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**Author:** [@nluetts](https://discourse.julialang.org/u/nluetts)\
**Replies:** 22\
**Last updated:** [August 4, 2021, 10:24am UTC](https://discourse.julialang.org/t/least-squares-fitting-that-accounts-for-covariance-matrix-of-all-input-parameters/64775 "2021-08-04T10:24:39Z")

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Hi, I am thinking about writing a package that implements a generalized least squares fitting method or perhaps seek to contribute somewhere where it might fit. Before I write more than my prototype, I wanted to double …

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## [How to show CuArray without copying from GPU to CPU?](https://discourse.julialang.org/t/how-to-show-cuarray-without-copying-from-gpu-to-cpu/65798)

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**Author:** [@wulalagiao](https://discourse.julialang.org/u/wulalagiao)\
**Replies:** 0\
**Last updated:** [August 4, 2021, 9:36am UTC](https://discourse.julialang.org/t/how-to-show-cuarray-without-copying-from-gpu-to-cpu/65798 "2021-08-04T09:36:57Z")

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I wanna display a CuArray(actually an image) to see how it changes during the computation, and I cannot figure out a method to do it.

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## [Handling fluid systems in MTK](https://discourse.julialang.org/t/handling-fluid-systems-in-mtk/65305)

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**Author:** [@ohmsweetohm1](https://discourse.julialang.org/u/ohmsweetohm1)\
**Replies:** 1\
**Last updated:** [August 4, 2021, 1:50am UTC](https://discourse.julialang.org/t/handling-fluid-systems-in-mtk/65305 "2021-08-04T01:50:45Z")

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In Modelica a fluid Connector has a medium property, see \[1\]. Is this possible with the existing parameter system in MTK? As I understand it it has to be a subtype of Real, which a medium would not. If a large fluid s…

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## [Choosing a Plotting Base to Build a Statistical Plotting Package](https://discourse.julialang.org/t/choosing-a-plotting-base-to-build-a-statistical-plotting-package/62240)

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**Author:** [@ParadaCarleton](https://discourse.julialang.org/u/ParadaCarleton)\
**Replies:** 19\
**Last updated:** [August 4, 2021, 12:39am UTC](https://discourse.julialang.org/t/choosing-a-plotting-base-to-build-a-statistical-plotting-package/62240 "2021-08-04T00:39:08Z")

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If I wanted to build a package that adds more kinds of statistical plots to Julia, what would be the best plotting package to build it on top of? (e.g. Plots.jl, Makie, Gadfly, VegaLite) What advantages/disadvantages do …

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## [Queryverse \`load(f) ▷ @take(3)\` appears to read the whole file](https://discourse.julialang.org/t/queryverse-load-f-take-3-appears-to-read-the-whole-file/63272)

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**Author:** [@dereksz](https://discourse.julialang.org/u/dereksz)\
**Replies:** 2\
**Last updated:** [August 3, 2021, 6:28pm UTC](https://discourse.julialang.org/t/queryverse-load-f-take-3-appears-to-read-the-whole-file/63272 "2021-08-03T18:28:13Z")

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Just watched David Anthoff’s awsome Introduction to the Queryverse video. David emphasises that the Queryverse is designed to work in a “streaming” fashion, and that data is supposed to be “pulled” through the stages in…

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## [Cannot specify symbolic types](https://discourse.julialang.org/t/cannot-specify-symbolic-types/65702)

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**Author:** [@yuvalw](https://discourse.julialang.org/u/yuvalw)\
**Replies:** 2\
**Last updated:** [August 3, 2021, 5:42pm UTC](https://discourse.julialang.org/t/cannot-specify-symbolic-types/65702 "2021-08-03T17:42:28Z")

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Hello, I cannot specify any symbolic type. using Symbolics @variables u::Complex # or any other type gives the following error: ERROR: LoadError: AssertionError: @variables expects a tuple of expressions or an expres…

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## [Why doesn't this work with DataFrames.jl \`combine\`?](https://discourse.julialang.org/t/why-doesnt-this-work-with-dataframes-jl-combine/65549)

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**Author:** [@xiaodai](https://discourse.julialang.org/u/xiaodai)\
**Replies:** 13\
**Last updated:** [August 3, 2021, 3:46pm UTC](https://discourse.julialang.org/t/why-doesnt-this-work-with-dataframes-jl-combine/65549 "2021-08-03T15:46:35Z")

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This works df = DataFrame( a = rand(1:8, 1000), b = rand(1:8, 1000), c = rand(1:8, 1000), ) combine(groupby(df, :a), nrow =\> :meh) # this works function \_meh(sdf) \[sdf\[!, Not(:a)\]\] end c…

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## [Using Zygote with custom CUDA kernels](https://discourse.julialang.org/t/using-zygote-with-custom-cuda-kernels/65688)

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**Author:** [@oscarknagg](https://discourse.julialang.org/u/oscarknagg)\
**Replies:** 3\
**Last updated:** [August 3, 2021, 1:11pm UTC](https://discourse.julialang.org/t/using-zygote-with-custom-cuda-kernels/65688 "2021-08-03T13:11:37Z")

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Hi all. I’m wondering if it’s possible to use Zygote to automatically differentiate CUDA kernels that I’ve defined. A minimal (not-quite working) example is below. My actual use case is not as trivial but this is essenti…

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## [Replacing one column with three (DataFrames.jl)](https://discourse.julialang.org/t/replacing-one-column-with-three-dataframes-jl/65565)

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**Author:** [@Alex-ZA](https://discourse.julialang.org/u/Alex-ZA)\
**Replies:** 3\
**Last updated:** [August 3, 2021, 11:19am UTC](https://discourse.julialang.org/t/replacing-one-column-with-three-dataframes-jl/65565 "2021-08-03T11:19:07Z")

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Hi everyone! My first post here. I have to say, loving the Julia language. It is quickly becoming my favourite. Also, fantastic work with Juno. It is awesome. I am trying to implement an “One Hot” transform on some…

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## [Simplify JSON while deserializing into struct with StructTypes.jl](https://discourse.julialang.org/t/simplify-json-while-deserializing-into-struct-with-structtypes-jl/65484)

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**Author:** [@Jakob](https://discourse.julialang.org/u/Jakob)\
**Replies:** 9\
**Last updated:** [August 3, 2021, 6:58am UTC](https://discourse.julialang.org/t/simplify-json-while-deserializing-into-struct-with-structtypes-jl/65484 "2021-08-03T06:58:29Z")

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Hi everyone, I have a relatively complex and nested JSON object (representing a patent application) which I would like to deserialize into a struct. However, I would like to “de-nest” the structure somewhat and between…

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## [How to make Zygote avoid differentiating with respect to some fields in struct](https://discourse.julialang.org/t/how-to-make-zygote-avoid-differentiating-with-respect-to-some-fields-in-struct/65520)

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**Author:** [@Nikos\_Gianniotis](https://discourse.julialang.org/u/Nikos_Gianniotis)\
**Replies:** 6\
**Last updated:** [August 2, 2021, 8:08pm UTC](https://discourse.julialang.org/t/how-to-make-zygote-avoid-differentiating-with-respect-to-some-fields-in-struct/65520 "2021-08-02T20:08:51Z")

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Hello everyone, I have been always used ForwardDiff for my automatic differentiation needs, but recently I thought I should try out Zygote instead. My main motivation for doing so is the ability of Zygote to work with c…

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## [Change Gtk Button color](https://discourse.julialang.org/t/change-gtk-button-color/62433)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 2\
**Last updated:** [August 1, 2021, 8:17pm UTC](https://discourse.julialang.org/t/change-gtk-button-color/62433 "2021-08-01T20:17:45Z")

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Hi all, I would like to change the color of a button in Gtk based on an event and change the color or darken the button when it is selected. Right now I am stuck simply trying to change the color. My approach is based …

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## [Problem optimizing a 2 variable function (Optim .jl)](https://discourse.julialang.org/t/problem-optimizing-a-2-variable-function-optim-jl/65655)

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**Author:** [@AndresCasillas](https://discourse.julialang.org/u/AndresCasillas)\
**Replies:** 4\
**Last updated:** [August 2, 2021, 2:05pm UTC](https://discourse.julialang.org/t/problem-optimizing-a-2-variable-function-optim-jl/65655 "2021-08-02T14:05:50Z")

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Hi! I want to optimize a 2 variable function using Optim.jl. I’ve read the documentation but I still can’t figure it out. I hope someone can help me. (I’m using Optim and using MittagLeffler on a Jupyter notebook with Ju…

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## [Makie: LinePattern in Box](https://discourse.julialang.org/t/makie-linepattern-in-box/65663)

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**Author:** [@wst](https://discourse.julialang.org/u/wst)\
**Replies:** 2\
**Last updated:** [August 2, 2021, 12:07pm UTC](https://discourse.julialang.org/t/makie-linepattern-in-box/65663 "2021-08-02T12:07:41Z")

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Hello everyone, to get better understanding of how Makie works I’m trying to visualize stacked composite-laminates. My current approach is to draw a Box for each lamina, which works fine. Now I want to add a hatching t…

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## [\[ANN\]¯SNM: simulated neural moments for ABC or Bayesian method of moments](https://discourse.julialang.org/t/ann-snm-simulated-neural-moments-for-abc-or-bayesian-method-of-moments/41592)

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**Author:** [@mcreel](https://discourse.julialang.org/u/mcreel)\
**Replies:** 2\
**Last updated:** [August 2, 2021, 9:06am UTC](https://discourse.julialang.org/t/ann-snm-simulated-neural-moments-for-abc-or-bayesian-method-of-moments/41592 "2021-08-02T09:06:11Z")

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SNM is a project to reduce the dimension of statistics used for Approximate Bayesian Computing or the method of simulated moments though use of neural nets. The project allows for creation and training of the neural net,…

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## [Nonlinear callback cplex](https://discourse.julialang.org/t/nonlinear-callback-cplex/65660)

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**Author:** [@Luca](https://discourse.julialang.org/u/Luca)\
**Replies:** 1\
**Last updated:** [August 2, 2021, 8:41am UTC](https://discourse.julialang.org/t/nonlinear-callback-cplex/65660 "2021-08-02T08:41:13Z")

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Dear all, I would like to implement non linear lazy constraint for a cplex model. For instance I would like to implement the following code: using CPLEX, JuMP model = Model(CPLEX.Optimizer) @variable(model, x \<= 10, In…

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## [Variables multiplication with JuMP.jl](https://discourse.julialang.org/t/variables-multiplication-with-jump-jl/65661)

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**Author:** [@ver\_kh](https://discourse.julialang.org/u/ver_kh)\
**Replies:** 1\
**Last updated:** [August 2, 2021, 8:40am UTC](https://discourse.julialang.org/t/variables-multiplication-with-jump-jl/65661 "2021-08-02T08:40:30Z")

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Hi all, I’m trying to multiply three JuMP variables within a function but getting an error: LoadError: Cannot multiply a quadratic expression by a variable Here is the simplified version of code: using JuMP, Ipopt f…

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## [Makie.contour plot into an array](https://discourse.julialang.org/t/makie-contour-plot-into-an-array/65652)

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**Author:** [@Dale\_James\_Black](https://discourse.julialang.org/u/Dale_James_Black)\
**Replies:** 2\
**Last updated:** [August 2, 2021, 5:45am UTC](https://discourse.julialang.org/t/makie-contour-plot-into-an-array/65652 "2021-08-02T05:45:23Z")

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Is there a way to turn a Makie.contour plot into an array? Either where the contour pixels are 1s and everything else is 0 or where the pixels enclosed by the values are 1s and everything else is a 0. I can use ImageEdge…

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## [Unexpected and unclear labels' grouping in the legend when using plotly(js) backend with subplots](https://discourse.julialang.org/t/unexpected-and-unclear-labels-grouping-in-the-legend-when-using-plotly-js-backend-with-subplots/65632)

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**Author:** [@gianmariomanca](https://discourse.julialang.org/u/gianmariomanca)\
**Replies:** 2\
**Last updated:** [August 2, 2021, 2:35am UTC](https://discourse.julialang.org/t/unexpected-and-unclear-labels-grouping-in-the-legend-when-using-plotly-js-backend-with-subplots/65632 "2021-08-02T02:35:03Z")

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begin using StatsPlots gr() # pgfplotsx() # plotlyjs() # plotly() serie1=rand(5) serie2=rand(5) serie3=rand(10) serie4=rand(10) pg = plot( plot(\[serie3 serie4\], label=\["Serie1" "Serie2"\]), plot(\[se…

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## [Vecp, transition matrix and kronecker product](https://discourse.julialang.org/t/vecp-transition-matrix-and-kronecker-product/64240)

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**Author:** [@marcobonici](https://discourse.julialang.org/u/marcobonici)\
**Replies:** 9\
**Last updated:** [August 2, 2021, 1:17am UTC](https://discourse.julialang.org/t/vecp-transition-matrix-and-kronecker-product/64240 "2021-08-02T01:17:17Z")

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Hi to everybody, Given 4 different matrices \\boldsymbol{A}, \\boldsymbol{C}, \\boldsymbol{D}, \\boldsymbol{E}, I want to evaluate the following quantity \\operatorname{vecp}(\\boldsymbol{A})^{T} \\boldsymbol{B}\_{n}^{+}(\\bol…

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## [DSP.jl power spectra normalization](https://discourse.julialang.org/t/dsp-jl-power-spectra-normalization/26162)

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**Author:** [@Marco-Congedo](https://discourse.julialang.org/u/Marco-Congedo)\
**Replies:** 4\
**Last updated:** [August 1, 2021, 2:48pm UTC](https://discourse.julialang.org/t/dsp-jl-power-spectra-normalization/26162 "2021-08-01T14:48:41Z")

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Can anyone explain the rationale behind the FFT normalization done in DSP.jl, for instance in the periodogram function ? Here below is the concerned code of the fft2pow! function, which computes the power spectra. I am…

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## [Moving from LMI toolbox (Matlab) to JuliaOpt](https://discourse.julialang.org/t/moving-from-lmi-toolbox-matlab-to-juliaopt/21001)

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**Author:** [@glemieux](https://discourse.julialang.org/u/glemieux)\
**Replies:** 18\
**Last updated:** [July 31, 2021, 5:31pm UTC](https://discourse.julialang.org/t/moving-from-lmi-toolbox-matlab-to-juliaopt/21001 "2021-07-31T17:31:09Z")

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Does anyone have experience in moving from Matlab’s LMI toolbox to the various JuliaOpt packages? I’m taking a non-linear dynamics course (AAE666 at Purdue) and we’ve just been introduced to linear matrix inequalities i…

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## [Importing ZipFile.ReadableFile into DataFrame](https://discourse.julialang.org/t/importing-zipfile-readablefile-into-dataframe/65587)

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**Author:** [@banksiaboy](https://discourse.julialang.org/u/banksiaboy)\
**Replies:** 3\
**Last updated:** [July 31, 2021, 10:55pm UTC](https://discourse.julialang.org/t/importing-zipfile-readablefile-into-dataframe/65587 "2021-07-31T22:55:06Z")

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I have used ZipFile to open a downloaded compound zipfile. I want to import several of the contained files into DataFrames. ZipFile.Reader for IOStream(\<file ./GBIF-Datasets/0333654-200613084148143.zip\>) containing 16 f…

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## [Help building a PID example](https://discourse.julialang.org/t/help-building-a-pid-example/27194)

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**Author:** [@Ronis\_BR](https://discourse.julialang.org/u/Ronis_BR)\
**Replies:** 11\
**Last updated:** [July 31, 2021, 2:30pm UTC](https://discourse.julialang.org/t/help-building-a-pid-example/27194 "2021-07-31T14:30:59Z")

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Hi guys! I am trying to use Flux.jl to build a PIDNN as shown here: PID Neural Network I started to code using only the proportional part. This, I need an input layer with 2 inputs and 1 output, and one output layer wi…

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## [MKLSparse: how to control thread affinity and the number of threads?](https://discourse.julialang.org/t/mklsparse-how-to-control-thread-affinity-and-the-number-of-threads/65601)

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**Author:** [@Gregstrq](https://discourse.julialang.org/u/Gregstrq)\
**Replies:** 0\
**Last updated:** [July 31, 2021, 2:14pm UTC](https://discourse.julialang.org/t/mklsparse-how-to-control-thread-affinity-and-the-number-of-threads/65601 "2021-07-31T14:14:17Z")

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As far as I understand, currently the go-to way if you need multithreaded Sparse Matrix operations is to interface with MKL using MKLSparse.jl. Now, imagine I have a machine with several NUMA nodes and want to run multi…

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## [Pluralisation of @NLparameter](https://discourse.julialang.org/t/pluralisation-of-nlparameter/61060)

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**Author:** [@path-doc](https://discourse.julialang.org/u/path-doc)\
**Replies:** 4\
**Last updated:** [July 30, 2021, 9:49pm UTC](https://discourse.julialang.org/t/pluralisation-of-nlparameter/61060 "2021-07-30T21:49:20Z")

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Hi I’m enjoying using JuMP, is there any reason why there is no pluralisation of @NLparameter ? I’ve had a peek at the macro file and the format of variables, constraints and expressions are the same. What would be th…

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## [PosDefException: matrix is not positive definite; Cholesky factorization failed](https://discourse.julialang.org/t/posdefexception-matrix-is-not-positive-definite-cholesky-factorization-failed/65518)

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**Author:** [@YummyPampers2](https://discourse.julialang.org/u/YummyPampers2)\
**Replies:** 9\
**Last updated:** [July 30, 2021, 5:39pm UTC](https://discourse.julialang.org/t/posdefexception-matrix-is-not-positive-definite-cholesky-factorization-failed/65518 "2021-07-30T17:39:31Z")

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Hello Julians: I am encountering the issue above when I am building a logistic regression model using the GLM package. I was able to catch a reply from @tim.holy that covered some functions that could potentially a…

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## [Makie: how to avoid dropdown menus overlapping?](https://discourse.julialang.org/t/makie-how-to-avoid-dropdown-menus-overlapping/65556)

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**Author:** [@HenriDeh](https://discourse.julialang.org/u/HenriDeh)\
**Replies:** 1\
**Last updated:** [July 30, 2021, 5:10pm UTC](https://discourse.julialang.org/t/makie-how-to-avoid-dropdown-menus-overlapping/65556 "2021-07-30T17:10:50Z")

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Hi, Here’s a MWE of a Makie Figure with two dropdown menus. f = Figure() f\[1,1\] = Menu(f, options = \["aaa", "bbb", "ccc"\]) f\[2,1\] = Menu(f, options = \["aaa", "bbb", "ccc"\], direction = :up) You’ll notice that when ope…

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## [Glitching plot in GLMakie when reopening an interactive figure](https://discourse.julialang.org/t/glitching-plot-in-glmakie-when-reopening-an-interactive-figure/65560)

<div class="topic-metadata">

**Author:** [@zornsllama](https://discourse.julialang.org/u/zornsllama)\
**Replies:** 0\
**Last updated:** [July 30, 2021, 4:39pm UTC](https://discourse.julialang.org/t/glitching-plot-in-glmakie-when-reopening-an-interactive-figure/65560 "2021-07-30T16:39:32Z")

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I am finding that interactive plots in GLMakie seem to glitch upon reopening a figure. What I mean by this is that when I initially run the code to produce an interactive plot, it displays correctly in the Makie window, …

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