# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=395

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**Page:** 396

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## [Numerical questions about spatially varying parameters for ParallelStencil.jl](https://discourse.julialang.org/t/numerical-questions-about-spatially-varying-parameters-for-parallelstencil-jl/53558)

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**Author:** [@ziyiyin97](https://discourse.julialang.org/u/ziyiyin97)\
**Replies:** 4\
**Last updated:** [January 20, 2021, 4:44am UTC](https://discourse.julialang.org/t/numerical-questions-about-spatially-varying-parameters-for-parallelstencil-jl/53558 "2021-01-20T04:44:42Z")

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Hi developers for ParallelStencil.jl, Hope you stepped into the new year with ease. I have experienced with your julia software in a while, thanks to your clear documentation and workflow! I have a couple of questions …

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## ["InexactError" when calling Optim](https://discourse.julialang.org/t/inexacterror-when-calling-optim/53568)

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**Author:** [@Michael\_Barmann](https://discourse.julialang.org/u/Michael_Barmann)\
**Replies:** 3\
**Last updated:** [January 19, 2021, 10:22pm UTC](https://discourse.julialang.org/t/inexacterror-when-calling-optim/53568 "2021-01-19T22:22:33Z")

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I’m writing a program to perform parameter estimation on a system of ODEs, and I keep getting this weird “InexactError” that I’ve spent hours unsuccessfully trying to figure out. Here is my call to the optimizer which i…

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## [MLJ: accessing model fields from resampler](https://discourse.julialang.org/t/mlj-accessing-model-fields-from-resampler/53551)

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**Author:** [@Pere](https://discourse.julialang.org/u/Pere)\
**Replies:** 4\
**Last updated:** [January 19, 2021, 9:37pm UTC](https://discourse.julialang.org/t/mlj-accessing-model-fields-from-resampler/53551 "2021-01-19T21:37:40Z")

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I have a composite model that has a parameter (alpha) that generates a probability distribution and then the features and samples are weighted according to this distribution. I also want the samples to be taken according…

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## [Positioning a volume with Makie](https://discourse.julialang.org/t/positioning-a-volume-with-makie/53621)

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**Author:** [@Flausi](https://discourse.julialang.org/u/Flausi)\
**Replies:** 2\
**Last updated:** [January 19, 2021, 6:54pm UTC](https://discourse.julialang.org/t/positioning-a-volume-with-makie/53621 "2021-01-19T18:54:04Z")

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Hello, I would like to plot a three-dimensional matrix as a volume at an arbitrary location in space with Makie.jl. using GLMakie using AbstractPlotting x = LinRange(1, 200, 200) y = LinRange(1, 200, 200) z = LinRange(…

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## [Warm-starting (set\_start\_value function) does not work in JuMP](https://discourse.julialang.org/t/warm-starting-set-start-value-function-does-not-work-in-jump/53620)

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**Author:** [@Shuvomoy\_Das\_Gupta](https://discourse.julialang.org/u/Shuvomoy_Das_Gupta)\
**Replies:** 2\
**Last updated:** [January 19, 2021, 5:59pm UTC](https://discourse.julialang.org/t/warm-starting-set-start-value-function-does-not-work-in-jump/53620 "2021-01-19T17:59:27Z")

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Dear All, I am trying to solve the following SDP with warm starting. The code is as follows using JuMP, COSMO # data m = 5 n = 10 using Random: bitrand c = randn(n) x0 = bitrand(n) A = randn(m, n) b = A \* x0 x\_pr…

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## [Simulated Method of Moments / Indirect inference: how might ModelingToolkit be extended to provide convenient user inteface?](https://discourse.julialang.org/t/simulated-method-of-moments-indirect-inference-how-might-modelingtoolkit-be-extended-to-provide-convenient-user-inteface/53395)

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**Author:** [@croberts](https://discourse.julialang.org/u/croberts)\
**Replies:** 16\
**Last updated:** [January 19, 2021, 5:39pm UTC](https://discourse.julialang.org/t/simulated-method-of-moments-indirect-inference-how-might-modelingtoolkit-be-extended-to-provide-convenient-user-inteface/53395 "2021-01-19T17:39:55Z")

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I am looking to estimate a simulated method of moments model. The most similar thread on SMM is from 2019 but does not settle issues: The most similar thread is: Global optimization: Simulated Method of Moments . Julia…

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## [Automatic inverse of a function?](https://discourse.julialang.org/t/automatic-inverse-of-a-function/53342)

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**Author:** [@lrnv](https://discourse.julialang.org/u/lrnv)\
**Replies:** 17\
**Last updated:** [January 19, 2021, 5:28pm UTC](https://discourse.julialang.org/t/automatic-inverse-of-a-function/53342 "2021-01-19T17:28:51Z")

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Hey, I do have a function that makes a heavy computation in Julia, from \\mathbb R^n to \\mathbb R^m. It uses loops, multiplications, additions, divisions, substractions, powers and exp/log. I am looking to inverse the f…

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## [Any way to delete an object and free memory?](https://discourse.julialang.org/t/any-way-to-delete-an-object-and-free-memory/53600)

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**Author:** [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)\
**Replies:** 5\
**Last updated:** [January 19, 2021, 2:19pm UTC](https://discourse.julialang.org/t/any-way-to-delete-an-object-and-free-memory/53600 "2021-01-19T14:19:50Z")

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Hi, I have a Monte Carlo simulation code that uses instances of a mutable struct that contain arrays. These arrays can be really large when the number of particles in the simulation increase. In the code, I have one ins…

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## [Problem with constrains for consequtive cases](https://discourse.julialang.org/t/problem-with-constrains-for-consequtive-cases/53599)

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**Author:** [@gustav.asbjorn](https://discourse.julialang.org/u/gustav.asbjorn)\
**Replies:** 1\
**Last updated:** [January 19, 2021, 1:15pm UTC](https://discourse.julialang.org/t/problem-with-constrains-for-consequtive-cases/53599 "2021-01-19T13:15:04Z")

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Hello there. I have problems creating some constrains that will satisfy the following case: We have 10 wokers that will work some days of a 14 day period in different timeintervals of the day: daytime, evening and night…

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## [Any advice on Stereo Matching in Julia?](https://discourse.julialang.org/t/any-advice-on-stereo-matching-in-julia/53552)

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**Author:** [@Erik\_Engheim](https://discourse.julialang.org/u/Erik_Engheim)\
**Replies:** 2\
**Last updated:** [January 19, 2021, 11:05am UTC](https://discourse.julialang.org/t/any-advice-on-stereo-matching-in-julia/53552 "2021-01-19T11:05:56Z")

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I am looking to do stereo matching in Julia, basically to find the depth in an image by using two images. I am at an early stage and would appreciate some advice on where to look for information, and what libraries are …

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## [Problems with constraint. Alternative for JuMP variable in if statement](https://discourse.julialang.org/t/problems-with-constraint-alternative-for-jump-variable-in-if-statement/53563)

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**Author:** [@gustav.asbjorn](https://discourse.julialang.org/u/gustav.asbjorn)\
**Replies:** 7\
**Last updated:** [January 19, 2021, 11:00am UTC](https://discourse.julialang.org/t/problems-with-constraint-alternative-for-jump-variable-in-if-statement/53563 "2021-01-19T11:00:28Z")

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Hey. So I need to implement the following: Let’s say that we have 10 workers. If they work in the weekend then they want to work both days of the weekend or none. If they work only one day of the weekend then we add a p…

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## [Error using getvalue](https://discourse.julialang.org/t/error-using-getvalue/53546)

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**Author:** [@RaquelSantos](https://discourse.julialang.org/u/RaquelSantos)\
**Replies:** 4\
**Last updated:** [January 18, 2021, 8:35pm UTC](https://discourse.julialang.org/t/error-using-getvalue/53546 "2021-01-18T20:35:09Z")

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Hello!! Whenever I try to use getvalue the following error appears to me: MethodError: no method matches getvalue (:: ConstraintRef {Model, JuMP.GenericRangeConstraint {JuMP.GenericAffExpr {Float64, Variable}}}) Could…

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## [Kanai-Tajimi Process (seismic simulation)](https://discourse.julialang.org/t/kanai-tajimi-process-seismic-simulation/53553)

<div class="topic-metadata">

**Author:** [@Frederic\_Gilt](https://discourse.julialang.org/u/Frederic_Gilt)\
**Replies:** 0\
**Last updated:** [January 18, 2021, 6:15pm UTC](https://discourse.julialang.org/t/kanai-tajimi-process-seismic-simulation/53553 "2021-01-18T18:15:25Z")

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Dear All, I am a basic user of Julia and was wondering if it’s possible to achieve simulations of mechanical structures facing seismic input modeled with Kanai-Tajami process There is a cool description of such kind of…

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## [How to convert String type columns of a dataframe to a DateTime type and a Float64 type, using either plain DataFrames.jl or Query.jl](https://discourse.julialang.org/t/how-to-convert-string-type-columns-of-a-dataframe-to-a-datetime-type-and-a-float64-type-using-either-plain-dataframes-jl-or-query-jl/53505)

<div class="topic-metadata">

**Author:** [@mocalvao](https://discourse.julialang.org/u/mocalvao)\
**Replies:** 4\
**Last updated:** [January 18, 2021, 10:55am UTC](https://discourse.julialang.org/t/how-to-convert-string-type-columns-of-a-dataframe-to-a-datetime-type-and-a-float64-type-using-either-plain-dataframes-jl-or-query-jl/53505 "2021-01-18T10:55:04Z")

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I have the following dataframe, with original columns of String type: using DataFrames df\_0 = DataFrame(Inicio = \["10 Jan 2021 15:00 ", "10 Jan 2021 16:43 ", "10 Jan 2021 17:13 "\], Q1 = \["0.50", "0.00", "0.50"\]) I a…

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## [How to delete a nonlinear constraint from a JuMP optimization problem](https://discourse.julialang.org/t/how-to-delete-a-nonlinear-constraint-from-a-jump-optimization-problem/53469)

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**Author:** [@boranzhao](https://discourse.julialang.org/u/boranzhao)\
**Replies:** 2\
**Last updated:** [January 18, 2021, 4:22am UTC](https://discourse.julialang.org/t/how-to-delete-a-nonlinear-constraint-from-a-jump-optimization-problem/53469 "2021-01-18T04:22:49Z")

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Hello, I know that delete can be used to delete constraints and variables from a JuMP problem. However, based on my testing, it does not work for nonlinear constraint added through @NLconstraint. I was wondering whether…

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## [Runtime Generated Functions](https://discourse.julialang.org/t/runtime-generated-functions/53507)

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**Author:** [@Ruchitha\_Kumar](https://discourse.julialang.org/u/Ruchitha_Kumar)\
**Replies:** 10\
**Last updated:** [January 18, 2021, 12:08am UTC](https://discourse.julialang.org/t/runtime-generated-functions/53507 "2021-01-18T00:08:46Z")

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Blockquote nlsys\_func = generate\_function(ns, \[x,y,z\], \[a,b,c\], expression=Val{false})\[2\] Generates : (::RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(Symbol(“##MTIIPVar#873”), Symbol(“##MTKArg#870”), Symbol(“##…

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## [Turing: help with multinomial likelihood](https://discourse.julialang.org/t/turing-help-with-multinomial-likelihood/53484)

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**Author:** [@drbenvincent](https://discourse.julialang.org/u/drbenvincent)\
**Replies:** 3\
**Last updated:** [January 17, 2021, 7:05pm UTC](https://discourse.julialang.org/t/turing-help-with-multinomial-likelihood/53484 "2021-01-17T19:05:01Z")

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Hi I’m running through a number of JAGS models, converting them to Turing. Mostly this is an easy process, but I’ve got stuck on what is probably something very simple. Original JAGS model: model{ alpha ~ dbeta(1,1) …

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## [Chemfiles -- contains](https://discourse.julialang.org/t/chemfiles-contains/53493)

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**Author:** [@aquarelleX332](https://discourse.julialang.org/u/aquarelleX332)\
**Replies:** 2\
**Last updated:** [January 17, 2021, 6:34pm UTC](https://discourse.julialang.org/t/chemfiles-contains/53493 "2021-01-17T18:34:36Z")

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Hello dear all, I tried to install Chemfiles.jl. During the test: julia\> Pkg.test("Chemfiles") I obtained an error: Test Summary: | Pass Total Generics | 1 1 Test Summary: | Pass Total Atom |…

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## [RNN (LSTM) Training issues with loss function](https://discourse.julialang.org/t/rnn-lstm-training-issues-with-loss-function/53483)

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**Author:** [@jparcinski](https://discourse.julialang.org/u/jparcinski)\
**Replies:** 0\
**Last updated:** [January 17, 2021, 12:11pm UTC](https://discourse.julialang.org/t/rnn-lstm-training-issues-with-loss-function/53483 "2021-01-17T12:11:36Z")

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Hi, I have problem with understanding 1 issue, maybe someone will help me. I’m trying to build LSTM or simple RNN for predicting price values. To start understand how to do it in Julia I used the example from here: A Ba…

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## [Makie in vmware player](https://discourse.julialang.org/t/makie-in-vmware-player/53439)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 1\
**Last updated:** [January 16, 2021, 8:32pm UTC](https://discourse.julialang.org/t/makie-in-vmware-player/53439 "2021-01-16T20:32:48Z")

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I am trying to make Makie.jl work within a virtual machine. I can install it successfully using the following setup: ubuntu 18.04 host with nvidia 390.141 driver cinamon 20.1 running in vmware player But when I execut…

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## [From Python-cgkit to Makie.jl](https://discourse.julialang.org/t/from-python-cgkit-to-makie-jl/52129)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 3\
**Last updated:** [January 16, 2021, 6:11pm UTC](https://discourse.julialang.org/t/from-python-cgkit-to-makie-jl/52129 "2021-01-16T18:11:27Z")

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I am trying to convert the 3D viewer of my kitepower system simulator (Bitbucket) to Julia/ Makie.jl. The old Python/C++ library is unsupported since 8 years and the newest system where it works is Ubuntu 14.04, so I …

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## [PoSTagger on other languages than English](https://discourse.julialang.org/t/postagger-on-other-languages-than-english/53385)

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**Author:** [@tencnivel](https://discourse.julialang.org/u/tencnivel)\
**Replies:** 2\
**Last updated:** [January 16, 2021, 5:00pm UTC](https://discourse.julialang.org/t/postagger-on-other-languages-than-english/53385 "2021-01-16T17:00:22Z")

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Has anyone manage to use TextModels PoSTagger on another language than English? The following does not work, everything gets tagged as ‘NNP’: using TextModels using TextAnalysis using Languages str = "André trouve cet…

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## [Plots (PyPlot) - Set legend title font size](https://discourse.julialang.org/t/plots-pyplot-set-legend-title-font-size/31763)

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**Author:** [@timmm](https://discourse.julialang.org/u/timmm)\
**Replies:** 2\
**Last updated:** [January 16, 2021, 2:40pm UTC](https://discourse.julialang.org/t/plots-pyplot-set-legend-title-font-size/31763 "2021-01-16T14:40:10Z")

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Hi, When using Plots (PyPlot backend) I cant seem to control the font size of the legends title: using Plots, LaTeXStrings pyplot() upscale = 2 #Xx upscaling in resolution p=plot( ) fntsm = Plots.font("sans-serif", po…

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## [User cuts and Lazy Constraints JuMP Gurobi](https://discourse.julialang.org/t/user-cuts-and-lazy-constraints-jump-gurobi/53328)

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**Author:** [@baprata](https://discourse.julialang.org/u/baprata)\
**Replies:** 4\
**Last updated:** [January 16, 2021, 8:43am UTC](https://discourse.julialang.org/t/user-cuts-and-lazy-constraints-jump-gurobi/53328 "2021-01-16T08:43:10Z")

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I am trying to insert user cuts and lazy constraints in a mixed-integer linear programming model. I am putting the functions in separate files from the main model. An illustrative example: function valid\_inequality(cb\_d…

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## [Finding roots of a complex transcedental function](https://discourse.julialang.org/t/finding-roots-of-a-complex-transcedental-function/53407)

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**Author:** [@Jake](https://discourse.julialang.org/u/Jake)\
**Replies:** 0\
**Last updated:** [January 15, 2021, 9:01pm UTC](https://discourse.julialang.org/t/finding-roots-of-a-complex-transcedental-function/53407 "2021-01-15T21:01:28Z")

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I am trying to do root-finding on a complex function. The function is a 3x3 matrix in the Laplacian domain. I would like to find the values of “s”, where the determinant of this matrix is zero. I am not sure what the …

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## [Help me to model and optimize an alternative wind turbine](https://discourse.julialang.org/t/help-me-to-model-and-optimize-an-alternative-wind-turbine/51532)

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**Author:** [@Impressium](https://discourse.julialang.org/u/Impressium)\
**Replies:** 6\
**Last updated:** [January 15, 2021, 7:58pm UTC](https://discourse.julialang.org/t/help-me-to-model-and-optimize-an-alternative-wind-turbine/51532 "2021-01-15T19:58:59Z")

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Heyy best community :slight\_smile: I’ve got this idea for a long time but didn’t had the time to share and visualize it. But here it is :smiley: I modeled it in a steady state and got: …

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## [Functions of GPUArrays in ODEs and scheduling on GPU](https://discourse.julialang.org/t/functions-of-gpuarrays-in-odes-and-scheduling-on-gpu/53304)

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**Author:** [@Gregstrq](https://discourse.julialang.org/u/Gregstrq)\
**Replies:** 11\
**Last updated:** [January 15, 2021, 11:31am UTC](https://discourse.julialang.org/t/functions-of-gpuarrays-in-odes-and-scheduling-on-gpu/53304 "2021-01-15T11:31:57Z")

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I have a totally noob question here. I know that there are GPUArrays for which broadcasting and various linear algebra stuff is overloaded, so it gets executed on GPU. Suppose, that I define a function which works with…

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## [Adding a new line to a candlestick plot](https://discourse.julialang.org/t/adding-a-new-line-to-a-candlestick-plot/53375)

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**Author:** [@colintbowers](https://discourse.julialang.org/u/colintbowers)\
**Replies:** 7\
**Last updated:** [January 15, 2021, 10:19am UTC](https://discourse.julialang.org/t/adding-a-new-line-to-a-candlestick-plot/53375 "2021-01-15T10:19:29Z")

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Hi all, The TimeSeries.jl package allows the construction of a candlestick plot. This works very nicely for me. However, sometimes I’d like to add another line to overlay the candlestick plot. I’ve been messing around f…

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## [KernelError with Flux.tain! on GPU](https://discourse.julialang.org/t/kernelerror-with-flux-tain-on-gpu/52989)

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**Author:** [@Geoffrey](https://discourse.julialang.org/u/Geoffrey)\
**Replies:** 4\
**Last updated:** [January 15, 2021, 8:42am UTC](https://discourse.julialang.org/t/kernelerror-with-flux-tain-on-gpu/52989 "2021-01-15T08:42:31Z")

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Hi, I’m trying to train denoising autoencoder for data imputation and I manage to get it work on CPU but I get a KernelError when trying to go on GPU. However, I checked that my loss function don’t produce error when us…

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## [ForwardDiff: "No Method Matching" Error](https://discourse.julialang.org/t/forwarddiff-no-method-matching-error/53311)

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**Author:** [@Michael\_Barmann](https://discourse.julialang.org/u/Michael_Barmann)\
**Replies:** 9\
**Last updated:** [January 15, 2021, 12:19am UTC](https://discourse.julialang.org/t/forwarddiff-no-method-matching-error/53311 "2021-01-15T00:19:25Z")

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I’m testing out the ForwardDiff package for the first time, but unfortunately I’m getting a “No Method Matching” error that I can’t figure out. I was successful in making the following test example by mimicking the one …

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