# Latest

**URL:** https://discourse.julialang.org/latest.md?page=827

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

**Page:** 828

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## [Julia, Machine Learning, and Finance](https://discourse.julialang.org/t/julia-machine-learning-and-finance/92171)

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**Author:** [@DPKMB](https://discourse.julialang.org/u/DPKMB)\
**Replies:** 1\
**Last updated:** [December 27, 2022, 3:12pm UTC](https://discourse.julialang.org/t/julia-machine-learning-and-finance/92171 "2022-12-27T15:12:39Z")

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Hello. I’ve previously asked about Julia and Finance. I’m currently going through one of the readily available introductory books on Julia. I came across this click-baity video from Siraj Learn Machine Learning in 3 Mont…

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## [Tullio and the nograd option](https://discourse.julialang.org/t/tullio-and-the-nograd-option/92123)

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**Author:** [@erlebach](https://discourse.julialang.org/u/erlebach)\
**Replies:** 13\
**Last updated:** [December 27, 2022, 2:33pm UTC](https://discourse.julialang.org/t/tullio-and-the-nograd-option/92123 "2022-12-27T14:33:56Z")

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@ChrisRackauckas , @mcabbott, I have a Tullio expression: Poly(coef) = @tullio poly\[i\] := coef\[j\] \* x\[i\]^I\[j\].x \* y\[i\]^I\[j\].y grad=Dual nograd=x nograd=y nograd=I I assumed that the nograd option expressed that these …

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## [How to Use InverseFunctions.jl that can Calculate the Inverse of a Function?](https://discourse.julialang.org/t/how-to-use-inversefunctions-jl-that-can-calculate-the-inverse-of-a-function/91931)

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**Author:** [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)\
**Replies:** 15\
**Last updated:** [December 27, 2022, 2:46pm UTC](https://discourse.julialang.org/t/how-to-use-inversefunctions-jl-that-can-calculate-the-inverse-of-a-function/91931 "2022-12-27T14:46:38Z")

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Hi all, I read the package here: https://juliamath.github.io/InverseFunctions.jl/stable/ I want to calculate simple inverse of a function: y^{2} = 4x I use this: using InverseFunctions foo(x) = sqrt(4x) inverse(fo…

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## [Fully-funded post-doc position at Toronto Metropolitan University](https://discourse.julialang.org/t/fully-funded-post-doc-position-at-toronto-metropolitan-university/92187)

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**Author:** [@bkamins](https://discourse.julialang.org/u/bkamins)\
**Replies:** 0\
**Last updated:** [December 27, 2022, 1:46pm UTC](https://discourse.julialang.org/t/fully-funded-post-doc-position-at-toronto-metropolitan-university/92187 "2022-12-27T13:46:24Z")

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I potentially have a fully-funded opportunity for a person interested in spending 6 months on a post-doc position at Toronto Metropolitan University (potentially also a person during PhD can be accepted). Time span is se…

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## [Problem while precompiling Javis](https://discourse.julialang.org/t/problem-while-precompiling-javis/92055)

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**Author:** [@Smettus](https://discourse.julialang.org/u/Smettus)\
**Replies:** 4\
**Last updated:** [December 27, 2022, 1:27pm UTC](https://discourse.julialang.org/t/problem-while-precompiling-javis/92055 "2022-12-27T13:27:25Z")

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For a project, I need my hands on a simple, yet effective SVG/other animation package. Javis, built on top of Luxor, seemed a viable option. However, while trying to install and precompile the package, I received the fol…

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## [Extend findmin/findmax functions in CUDA](https://discourse.julialang.org/t/extend-findmin-findmax-functions-in-cuda/92184)

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**Author:** [@fedoroff](https://discourse.julialang.org/u/fedoroff)\
**Replies:** 0\
**Last updated:** [December 27, 2022, 1:09pm UTC](https://discourse.julialang.org/t/extend-findmin-findmax-functions-in-cuda/92184 "2022-12-27T13:09:41Z")

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Currently the findmin/findmax functions in CUDA are defined for cases where one passes in them only a single CuArray (link), e.g. findmin(a). However, findmin/findmax functions in Base allow to pass in them an additional…

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## [Plotting a mesh with transparency with MeshViz.jl](https://discourse.julialang.org/t/plotting-a-mesh-with-transparency-with-meshviz-jl/92002)

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**Author:** [@\_stla](https://discourse.julialang.org/u/_stla)\
**Replies:** 1\
**Last updated:** [December 27, 2022, 12:05pm UTC](https://discourse.julialang.org/t/plotting-a-mesh-with-transparency-with-meshviz-jl/92002 "2022-12-27T12:05:30Z")

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I have a mesh made with Meshes.jl and I plot it with MeshViz.jl. There’s a alpha parameter to set the transparency. When I use it, here is the result I obtain: How to solve this issue?

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## [How to document a method where the leading arguments are optional?](https://discourse.julialang.org/t/how-to-document-a-method-where-the-leading-arguments-are-optional/92180)

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**Author:** [@jishnub](https://discourse.julialang.org/u/jishnub)\
**Replies:** 3\
**Last updated:** [December 27, 2022, 10:55am UTC](https://discourse.julialang.org/t/how-to-document-a-method-where-the-leading-arguments-are-optional/92180 "2022-12-27T10:55:04Z")

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The julia docstring convention for a function f(x,y) where the second argument is optional, is: f(x, y=1) Here 1 is the default value of the argument. This coincides nicely with the method definition. What does one do,…

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## [How to extract sampled values from a Turing model](https://discourse.julialang.org/t/how-to-extract-sampled-values-from-a-turing-model/92157)

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**Author:** [@affans](https://discourse.julialang.org/u/affans)\
**Replies:** 1\
**Last updated:** [December 27, 2022, 9:58am UTC](https://discourse.julialang.org/t/how-to-extract-sampled-values-from-a-turing-model/92157 "2022-12-27T09:58:56Z")

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I have implemented a Bayesian model and I am interested in extracting the results. I’d like to first assess convergence of the MCMC chains but also extract the values for the parameters. chain = sample(model\_fun, sample…

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## [How to perform parallel vector addition?](https://discourse.julialang.org/t/how-to-perform-parallel-vector-addition/92122)

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**Author:** [@27rabbitlt](https://discourse.julialang.org/u/27rabbitlt)\
**Replies:** 24\
**Last updated:** [December 27, 2022, 6:40am UTC](https://discourse.julialang.org/t/how-to-perform-parallel-vector-addition/92122 "2022-12-27T06:40:09Z")

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Hi guys~ I’m completely new to Julia and I just installed Julia this morning, so this question might seem a bit stupid. I’ve learned that Julia has JIT and well-supported multithreading, so I just want to check it out.…

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## [Faster quadratic expression for symmetric matrices](https://discourse.julialang.org/t/faster-quadratic-expression-for-symmetric-matrices/91843)

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**Author:** [@corbat](https://discourse.julialang.org/u/corbat)\
**Replies:** 12\
**Last updated:** [December 27, 2022, 6:04am UTC](https://discourse.julialang.org/t/faster-quadratic-expression-for-symmetric-matrices/91843 "2022-12-27T06:04:16Z")

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Hi, I have a use case where I need to evaluate many quadratic expressions of the form x^T M x, with the matrix M always beeing symmetric. The typical dimensionality of M is between 3 and 3000. Using the following two ap…

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## [How to Animate Solid of Revolution from SemiCircle to Torus?](https://discourse.julialang.org/t/how-to-animate-solid-of-revolution-from-semicircle-to-torus/92178)

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**Author:** [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)\
**Replies:** 0\
**Last updated:** [December 27, 2022, 5:41am UTC](https://discourse.julialang.org/t/how-to-animate-solid-of-revolution-from-semicircle-to-torus/92178 "2022-12-27T05:41:01Z")

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Hi all, I want to know how to create animation, from semicircle become cone then torus like this? So People can imagine how it looks like. This is called Solids of Revolution: Method of Disks. When a plane region rev…

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## [JupyterLab vs PlotlyJS](https://discourse.julialang.org/t/jupyterlab-vs-plotlyjs/92173)

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**Author:** [@rmfritz](https://discourse.julialang.org/u/rmfritz)\
**Replies:** 0\
**Last updated:** [December 27, 2022, 12:14am UTC](https://discourse.julialang.org/t/jupyterlab-vs-plotlyjs/92173 "2022-12-27T00:14:46Z")

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The following example works fine in the julia REPL, but only produces an empty cell in IJulia under JupyterLab. I’ve done a couple of installs I found on the net, and none of them worked. Any ideas about what to try? us…

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## [How to convert the python code below to julia?](https://discourse.julialang.org/t/how-to-convert-the-python-code-below-to-julia/92151)

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**Author:** [@jcbritobr](https://discourse.julialang.org/u/jcbritobr)\
**Replies:** 12\
**Last updated:** [December 26, 2022, 10:05pm UTC](https://discourse.julialang.org/t/how-to-convert-the-python-code-below-to-julia/92151 "2022-12-26T22:05:56Z")

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Hello, good afternoon, How to convert the below code from python to julia? from numpy import array # Transformation 1 i\_hat1 = array(\[0, 1\]) j\_hat1 = array(\[-1, 0\]) transform1 = array(\[i\_hat1, j\_hat1\]).transpose() # Tr…

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## [REPL color questions: variable names, seeing them, and setting RGB values](https://discourse.julialang.org/t/repl-color-questions-variable-names-seeing-them-and-setting-rgb-values/88743)

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**Author:** [@matw](https://discourse.julialang.org/u/matw)\
**Replies:** 13\
**Last updated:** [December 26, 2022, 9:37pm UTC](https://discourse.julialang.org/t/repl-color-questions-variable-names-seeing-them-and-setting-rgb-values/88743 "2022-12-26T21:37:51Z")

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The REPL’s package mode prompt is too dark, and I want to change it. I’ve found the REPL documentation, and it shows how to set variables using startup.jl, and I now have a few questions that go beyond changing the prom…

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## [Could anyone make this run faster?](https://discourse.julialang.org/t/could-anyone-make-this-run-faster/92145)

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**Author:** [@Ahmed\_Salih](https://discourse.julialang.org/u/Ahmed_Salih)\
**Replies:** 21\
**Last updated:** [December 26, 2022, 9:09pm UTC](https://discourse.julialang.org/t/could-anyone-make-this-run-faster/92145 "2022-12-26T21:09:38Z")

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Hello! I apologize for using unicode characters before hand, but I really like it :slight\_smile: I have a function given as: function ∇ᵢWᵢⱼ(αD,q,xᵢⱼ,h) # Skip distances outside the support of the kernel: if q \< …

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## [Improving performance: large amount of time on getindex and setindex!](https://discourse.julialang.org/t/improving-performance-large-amount-of-time-on-getindex-and-setindex/92166)

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**Author:** [@james3](https://discourse.julialang.org/u/james3)\
**Replies:** 1\
**Last updated:** [December 26, 2022, 8:46pm UTC](https://discourse.julialang.org/t/improving-performance-large-amount-of-time-on-getindex-and-setindex/92166 "2022-12-26T20:46:58Z")

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I am trying to improve the performance of my code. If I profile (Profile.@profile), ~40% of the time is spent on getindex and setindex!. My code is making extensive use of multidimensional arrays, which I suspect is resp…

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## [How to generate random RGB values through which black text is reliably visible?](https://discourse.julialang.org/t/how-to-generate-random-rgb-values-through-which-black-text-is-reliably-visible/92148)

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**Author:** [@Colin\_Beckingham](https://discourse.julialang.org/u/Colin_Beckingham)\
**Replies:** 4\
**Last updated:** [December 26, 2022, 8:40pm UTC](https://discourse.julialang.org/t/how-to-generate-random-rgb-values-through-which-black-text-is-reliably-visible/92148 "2022-12-26T20:40:10Z")

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I’d like to constrain the randomly coloured nodes in my graphplot to light colours through which black font text is reliably visible. The functions in Random do not operate well with RGB since math is not permitted. How …

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## [GLMakie beginners help: Multiple sliders and an arrow](https://discourse.julialang.org/t/glmakie-beginners-help-multiple-sliders-and-an-arrow/92113)

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**Author:** [@manya](https://discourse.julialang.org/u/manya)\
**Replies:** 4\
**Last updated:** [December 26, 2022, 8:36pm UTC](https://discourse.julialang.org/t/glmakie-beginners-help-multiple-sliders-and-an-arrow/92113 "2022-12-26T20:36:27Z")

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Hi, I am learning sliders from this tutorial line 18 to 87 \[tutorials/Tutorial02x10.jl at master · julia4ta/tutorials · GitHub\] and trying to edit such that it includes multiple sliders and an arrow from a reference poi…

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## [\[ANN\] Makie.jl 0.19](https://discourse.julialang.org/t/ann-makie-jl-0-19/91184)

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**Author:** [@jules](https://discourse.julialang.org/u/jules)\
**Replies:** 14\
**Last updated:** [December 26, 2022, 6:39pm UTC](https://discourse.julialang.org/t/ann-makie-jl-0-19/91184 "2022-12-26T18:39:53Z")

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Makie.jl v0.19 is a small minor release containing only two relevant changes. First, there’s a breaking change: All occurrences of textsize are now fontsize, so search and replace that word and you will be good to go. T…

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## [Issues with distributed package](https://discourse.julialang.org/t/issues-with-distributed-package/92158)

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**Author:** [@tomd](https://discourse.julialang.org/u/tomd)\
**Replies:** 0\
**Last updated:** [December 26, 2022, 6:14pm UTC](https://discourse.julialang.org/t/issues-with-distributed-package/92158 "2022-12-26T18:14:59Z")

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Hello! I have a code which has to deal with large arrays: l = length(A) m = 56^2 flag = trues(l) flatten\_connectivity = Array{Float32, 2}(undef, l, m) for i = 1:l flatten\_connectivity\[i, :\] …

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## [How to draw a dot with PyPlot?](https://discourse.julialang.org/t/how-to-draw-a-dot-with-pyplot/92134)

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**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 2\
**Last updated:** [December 26, 2022, 5:31pm UTC](https://discourse.julialang.org/t/how-to-draw-a-dot-with-pyplot/92134 "2022-12-26T17:31:18Z")

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Hello, I can write a marker on a plot generated with PyPlot with: scatter(X, Y, s = 25, color = "red", marker="x") However, I don’t like the x as a marker (it looks too much as a treasure map…). I tried to apply the …

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## [Alternate y-axis in Plotting](https://discourse.julialang.org/t/alternate-y-axis-in-plotting/92152)

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**Author:** [@Jake](https://discourse.julialang.org/u/Jake)\
**Replies:** 0\
**Last updated:** [December 26, 2022, 5:19pm UTC](https://discourse.julialang.org/t/alternate-y-axis-in-plotting/92152 "2022-12-26T17:19:02Z")

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I am using Plots to build a plot line by line. My initial intent was to plot one line using the left y-axis and then the next line using the right y-axis. For the first time through, using twinx() works well. Howeve…

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## [Error occured after the first precompilation on some packages after upadting to Julia 1.8.4](https://discourse.julialang.org/t/error-occured-after-the-first-precompilation-on-some-packages-after-upadting-to-julia-1-8-4/92138)

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**Author:** [@Shayan](https://discourse.julialang.org/u/Shayan)\
**Replies:** 4\
**Last updated:** [December 26, 2022, 2:32pm UTC](https://discourse.julialang.org/t/error-occured-after-the-first-precompilation-on-some-packages-after-upadting-to-julia-1-8-4/92138 "2022-12-26T14:32:04Z")

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I updated Julia using the Juliaup and now I can’t precompile some packages. Does this happen to everyone? julia\> using Plots \[ Info: Precompiling Plots \[91a5bcdd-55d7-5caf-9e0b-520d859cae80\] I break the error into seve…

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## [Example of hierarchical model in Turing](https://discourse.julialang.org/t/example-of-hierarchical-model-in-turing/19554)

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**Author:** [@Christopher\_Fisher](https://discourse.julialang.org/u/Christopher_Fisher)\
**Replies:** 9\
**Last updated:** [December 26, 2022, 2:46pm UTC](https://discourse.julialang.org/t/example-of-hierarchical-model-in-turing/19554 "2022-12-26T14:46:51Z")

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Hi all- I have been looking for an example of a hierarchical model in Turing.jl but have not found one. I was wondering if anyone has an example or could show me how to implement a simple example, such as a hierarchical…

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## [Julia for Scientists: summary slides](https://discourse.julialang.org/t/julia-for-scientists-summary-slides/91397)

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**Author:** [@tfiers](https://discourse.julialang.org/u/tfiers)\
**Replies:** 40\
**Last updated:** [December 26, 2022, 1:44pm UTC](https://discourse.julialang.org/t/julia-for-scientists-summary-slides/91397 "2022-12-26T13:44:09Z")

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I gave a presentation on Julia today, for staff of my uni’s Psychology department. Many interested people in the audience! These are the slides: (It starts slow but quickly goes into more nerdy terrain; The audience…

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## [Method error in Julia code](https://discourse.julialang.org/t/method-error-in-julia-code/91805)

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**Author:** [@hamza\_malik](https://discourse.julialang.org/u/hamza_malik)\
**Replies:** 10\
**Last updated:** [December 26, 2022, 12:49pm UTC](https://discourse.julialang.org/t/method-error-in-julia-code/91805 "2022-12-26T12:49:09Z")

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I am running this code but it shows a method error. Can someone please help me? Code: function lsmc\_am\_put(S, K, r, σ, t, N, P) Δt = t / N R = exp(r \* Δt) T = typeof(S \* exp(-σ^2 \* Δt / 2 + σ \* √Δt \* 0.1) /…

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## [Flux on Production enviroment](https://discourse.julialang.org/t/flux-on-production-enviroment/92136)

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**Author:** [@shivance](https://discourse.julialang.org/u/shivance)\
**Replies:** 2\
**Last updated:** [December 26, 2022, 12:17pm UTC](https://discourse.julialang.org/t/flux-on-production-enviroment/92136 "2022-12-26T12:17:21Z")

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We came across this thread (which dates back to two years), which pretty much demonstrates the state of Flux in production environment, which remains intact. Julia is indeed provides a tech stack, which a company once ch…

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## [CellListMap: Go from list of pairs to list of indices](https://discourse.julialang.org/t/celllistmap-go-from-list-of-pairs-to-list-of-indices/91974)

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**Author:** [@Ahmed\_Salih](https://discourse.julialang.org/u/Ahmed_Salih)\
**Replies:** 8\
**Last updated:** [December 26, 2022, 11:30am UTC](https://discourse.julialang.org/t/celllistmap-go-from-list-of-pairs-to-list-of-indices/91974 "2022-12-26T11:30:26Z")

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Hello! I am using CellListMap to generate a neighbour list of the type: ListOfPairs = (1,4,0.04) (1,3,0.02) (1,8,0.09) (2,1,0.01) (2,4,0.05) Where first index is “i”, second index is “j” and third index is the eu…

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## [General Plotting Code for Cone in 3D with GLMakie or Plots](https://discourse.julialang.org/t/general-plotting-code-for-cone-in-3d-with-glmakie-or-plots/92104)

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**Author:** [@Freya\_the\_Goddess](https://discourse.julialang.org/u/Freya_the_Goddess)\
**Replies:** 3\
**Last updated:** [December 26, 2022, 10:24am UTC](https://discourse.julialang.org/t/general-plotting-code-for-cone-in-3d-with-glmakie-or-plots/92104 "2022-12-26T10:24:25Z")

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Hi all, so I want to plot a general cone of pyramid and a right circular cone, I get this formula: But I think the plotting does not use the volume formula. Because of this torus code for GLMakie that I have: using …

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