# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=254

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

**Page:** 255

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## [Usage of CUDA.CUFFT.cufftPlanMany](https://discourse.julialang.org/t/usage-of-cuda-cufft-cufftplanmany/86403)

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**Author:** [@gerhardu](https://discourse.julialang.org/u/gerhardu)\
**Replies:** 1\
**Last updated:** [August 30, 2022, 6:32pm UTC](https://discourse.julialang.org/t/usage-of-cuda-cufft-cufftplanmany/86403 "2022-08-30T18:32:41Z")

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Hi, I need to calculate approx 600 FFT’s of 3 dimensional arrays (e.g. 128^3). I know how to do this on CPUs and also how to do this sequentially on a GPU. By sequentially I mean that I copy one of the 600 arrays to t…

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## [Symbolics and polynomials](https://discourse.julialang.org/t/symbolics-and-polynomials/86541)

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**Author:** [@qwerty](https://discourse.julialang.org/u/qwerty)\
**Replies:** 0\
**Last updated:** [August 30, 2022, 11:23am UTC](https://discourse.julialang.org/t/symbolics-and-polynomials/86541 "2022-08-30T11:23:50Z")

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What is the best package for working with polynomials with Symbolics.jl?

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## [User cut with JuMP and Gurobi](https://discourse.julialang.org/t/user-cut-with-jump-and-gurobi/86518)

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**Author:** [@Luiz\_Monteiro](https://discourse.julialang.org/u/Luiz_Monteiro)\
**Replies:** 1\
**Last updated:** [August 29, 2022, 11:18pm UTC](https://discourse.julialang.org/t/user-cut-with-jump-and-gurobi/86518 "2022-08-29T23:18:57Z")

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Hi, I am trying to insert user cuts in a mixed-integer linear programming model (Location-routing problem). I’m using the sintax presented in JuMP documentation (Callbacks · JuMP), and model in direct mode (model1 = dir…

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## [Converting an image rotation demo from JuliaCon 2021 (AMD -\> NVIDIA)](https://discourse.julialang.org/t/converting-an-image-rotation-demo-from-juliacon-2021-amd-nvidia/86365)

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**Author:** [@aaron\_pung](https://discourse.julialang.org/u/aaron_pung)\
**Replies:** 3\
**Last updated:** [August 29, 2022, 7:32pm UTC](https://discourse.julialang.org/t/converting-an-image-rotation-demo-from-juliacon-2021-amd-nvidia/86365 "2022-08-29T19:32:02Z")

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I’ve been trying to convert the rotate\_kernel function from the 2021 JuliaCon GPU Workshop to work with CUDA, but I’m having trouble. I’m new to building kernels on the GPU, but my current implementation of these functi…

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## [Symbolics and Polynomial](https://discourse.julialang.org/t/symbolics-and-polynomial/86503)

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**Author:** [@qwerty](https://discourse.julialang.org/u/qwerty)\
**Replies:** 3\
**Last updated:** [August 29, 2022, 7:31pm UTC](https://discourse.julialang.org/t/symbolics-and-polynomial/86503 "2022-08-29T19:31:24Z")

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Is there a function that lets you know if a given expression is a polynomial?

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## [Makie - Use of textbox validator](https://discourse.julialang.org/t/makie-use-of-textbox-validator/86487)

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**Author:** [@JB\_15](https://discourse.julialang.org/u/JB_15)\
**Replies:** 4\
**Last updated:** [August 29, 2022, 3:45pm UTC](https://discourse.julialang.org/t/makie-use-of-textbox-validator/86487 "2022-08-29T15:45:27Z")

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Hi I’m trying to use the validator from the Makie Textbox https://makie.juliaplots.org/v0.17.13/examples/blocks/textbox/index.html Could anybody give me an example of how to use the validator? My goal is to verify th…

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## [Error using CuIterator with Flux.train!](https://discourse.julialang.org/t/error-using-cuiterator-with-flux-train/86436)

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**Author:** [@taotree](https://discourse.julialang.org/u/taotree)\
**Replies:** 2\
**Last updated:** [August 29, 2022, 1:54pm UTC](https://discourse.julialang.org/t/error-using-cuiterator-with-flux-train/86436 "2022-08-29T13:54:59Z")

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I’m trying to use CuIterator and Flux.train!. Attempting to do so gives an error because train! tries to get the length of the CuIterator. So this: iter = CuIterator(batch(i) for i in 1:BATCH\_COUNT) Flux.train!(loss, ps…

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## [Symbolics.jl and struct](https://discourse.julialang.org/t/symbolics-jl-and-struct/86490)

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**Author:** [@qwerty](https://discourse.julialang.org/u/qwerty)\
**Replies:** 4\
**Last updated:** [August 29, 2022, 11:08am UTC](https://discourse.julialang.org/t/symbolics-jl-and-struct/86490 "2022-08-29T11:08:44Z")

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Should I create structs when using Symbolics.jl or is it better not to use structs and always work with purely symbolic expressions? For example, if I wanted to create my functions for calculating the truncated Taylor s…

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## [Custom backpropagation rule on GPU](https://discourse.julialang.org/t/custom-backpropagation-rule-on-gpu/86459)

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**Author:** [@Jakub\_Mitura](https://discourse.julialang.org/u/Jakub_Mitura)\
**Replies:** 2\
**Last updated:** [August 29, 2022, 8:23am UTC](https://discourse.julialang.org/t/custom-backpropagation-rule-on-gpu/86459 "2022-08-29T08:23:37Z")

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Hello I am trying to define the custom Chainrules rrule to be able to use Enzyme on selected functions for backpropagation done generally with Zygote . Kernel and taking derivatives using enzyme works. However, taking ja…

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## [Simple CuArray conversion, reverse, and transpose taking too long?](https://discourse.julialang.org/t/simple-cuarray-conversion-reverse-and-transpose-taking-too-long/86337)

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**Author:** [@aaron\_pung](https://discourse.julialang.org/u/aaron_pung)\
**Replies:** 3\
**Last updated:** [August 29, 2022, 7:57am UTC](https://discourse.julialang.org/t/simple-cuarray-conversion-reverse-and-transpose-taking-too-long/86337 "2022-08-29T07:57:03Z")

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I am ingesting a NetCDF file using the NCDatasets package; the resulting array of type Matrix{Float32} has size (32768,1000). Afterwards, I’m converting the array to a CuArray: \`\`\`using CUDA using NCDatasets CUDA.allow…

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## [Tree corresponding to expression in Symbolics](https://discourse.julialang.org/t/tree-corresponding-to-expression-in-symbolics/86034)

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**Author:** [@qwerty](https://discourse.julialang.org/u/qwerty)\
**Replies:** 3\
**Last updated:** [August 28, 2022, 6:59pm UTC](https://discourse.julialang.org/t/tree-corresponding-to-expression-in-symbolics/86034 "2022-08-28T18:59:57Z")

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In a video on YB I saw that you can get the tree corresponding to the expression with unwrap. tree\_expr = unwrap(sin(cos(x))) How can i access the elements of the tree? Also I saw that it can be displayed with: show…

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## [LinearSolve and SparseArrays: reuse factorization for multiple right-hand side vectors?](https://discourse.julialang.org/t/linearsolve-and-sparsearrays-reuse-factorization-for-multiple-right-hand-side-vectors/85003)

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**Author:** [@afas](https://discourse.julialang.org/u/afas)\
**Replies:** 2\
**Last updated:** [August 29, 2022, 1:15am UTC](https://discourse.julialang.org/t/linearsolve-and-sparsearrays-reuse-factorization-for-multiple-right-hand-side-vectors/85003 "2022-08-29T01:15:51Z")

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Hi everyone, I am implementing several Finite Element procedures in Julia and I am trying to switch all the implementation to use LinearSolve. I would like to know if it is possible to reuse a symbolic factorization of …

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## [BigFloat converted to string returns different number?](https://discourse.julialang.org/t/bigfloat-converted-to-string-returns-different-number/86473)

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**Author:** [@HelloThere](https://discourse.julialang.org/u/HelloThere)\
**Replies:** 8\
**Last updated:** [August 28, 2022, 11:20pm UTC](https://discourse.julialang.org/t/bigfloat-converted-to-string-returns-different-number/86473 "2022-08-28T23:20:47Z")

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Hi, I am new to Julia and in the documentation I came across this: julia\> big"1.23456789012345678901" 1.234567890123456789010000000000000000000000000000000000000000000000000000000004 At first I thought that this is so…

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## [How to multiply matrices with different structure?](https://discourse.julialang.org/t/how-to-multiply-matrices-with-different-structure/86428)

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**Author:** [@ivzktch99](https://discourse.julialang.org/u/ivzktch99)\
**Replies:** 2\
**Last updated:** [August 28, 2022, 9:42pm UTC](https://discourse.julialang.org/t/how-to-multiply-matrices-with-different-structure/86428 "2022-08-28T21:42:10Z")

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I am defining a variable X as a lower trianglar matrix (to reduce the number of variables). How can I multiply it with another dense matrix Y? The following gives me an error using JuMP using LinearAlgebra model = Mode…

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## [Suggestions for the design of Survey.jl?](https://discourse.julialang.org/t/suggestions-for-the-design-of-survey-jl/86381)

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**Author:** [@iuliadmtru](https://discourse.julialang.org/u/iuliadmtru)\
**Replies:** 3\
**Last updated:** [August 28, 2022, 8:18pm UTC](https://discourse.julialang.org/t/suggestions-for-the-design-of-survey-jl/86381 "2022-08-28T20:18:05Z")

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Hello, We are building Survey.jl, a package for statistical estimates from surveys. The inspiration for the package comes from the corresponding R survey package created by Thomas Lumley. We started out imitating the R…

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## [Find cycles in a direct graph (simplecycles error: function not defined)](https://discourse.julialang.org/t/find-cycles-in-a-direct-graph-simplecycles-error-function-not-defined/86449)

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**Author:** [@Luiz\_Monteiro](https://discourse.julialang.org/u/Luiz_Monteiro)\
**Replies:** 3\
**Last updated:** [August 28, 2022, 12:15pm UTC](https://discourse.julialang.org/t/find-cycles-in-a-direct-graph-simplecycles-error-function-not-defined/86449 "2022-08-28T12:15:18Z")

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Hi, I need to find cycles in a direct graph and return the vector of nodes of each cycle. I am using Graphs, LightGraphs, SimpleWeightedGraphs. Example: For a direct graph with the arcs \[(1 3), (2 4), (3 1), (4 5), (5, …

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## [Problem with MathOptInterface.jl @ 1.7.0](https://discourse.julialang.org/t/problem-with-mathoptinterface-jl-1-7-0/86450)

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**Author:** [@lionisxn](https://discourse.julialang.org/u/lionisxn)\
**Replies:** 5\
**Last updated:** [August 28, 2022, 11:29am UTC](https://discourse.julialang.org/t/problem-with-mathoptinterface-jl-1-7-0/86450 "2022-08-28T11:29:04Z")

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Does anyone encounter a crash on Julia 1.8.0 when using the latest version JuMP.jl and MathOptInterface.jl @ 1.7.0? The following pop-up messages are displayed on my computer running windows 11. However, when switched t…

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## [Makie plot recipe collections?](https://discourse.julialang.org/t/makie-plot-recipe-collections/86434)

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**Author:** [@fedario](https://discourse.julialang.org/u/fedario)\
**Replies:** 3\
**Last updated:** [August 27, 2022, 8:27pm UTC](https://discourse.julialang.org/t/makie-plot-recipe-collections/86434 "2022-08-27T20:27:02Z")

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Hi community! I noticed that Makie.jl enables you to create custom recipes. Before I start creating something myself, I thought I’d ask: Are there repositories containing collections of recipes that extend Makie’s defau…

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## [Symbolics avoid simplifications with rules](https://discourse.julialang.org/t/symbolics-avoid-simplifications-with-rules/86421)

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**Author:** [@qwerty](https://discourse.julialang.org/u/qwerty)\
**Replies:** 2\
**Last updated:** [August 27, 2022, 2:39pm UTC](https://discourse.julialang.org/t/symbolics-avoid-simplifications-with-rules/86421 "2022-08-27T14:39:04Z")

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How can I avoid simplification before applying a rule in Symbolics? I have (xy-yx) and I want to replace it with commutator(x, y), but before the rule can be applied xy-yx is simplified to 0.

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## [What is the Flux.flatten inverse operation?](https://discourse.julialang.org/t/what-is-the-flux-flatten-inverse-operation/86413)

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**Author:** [@taotree](https://discourse.julialang.org/u/taotree)\
**Replies:** 2\
**Last updated:** [August 27, 2022, 5:06am UTC](https://discourse.julialang.org/t/what-is-the-flux-flatten-inverse-operation/86413 "2022-08-27T05:06:12Z")

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My input data is multivariate time series, so the input array is width x length x batch. It appears a Dense layer requires the data to be in a single dimension, so I thought this is what Flux.flatten is for. On the outpu…

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## [Optimiser to get the best selection of a set of penalty values](https://discourse.julialang.org/t/optimiser-to-get-the-best-selection-of-a-set-of-penalty-values/86376)

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**Author:** [@ayodyas](https://discourse.julialang.org/u/ayodyas)\
**Replies:** 5\
**Last updated:** [August 26, 2022, 11:48pm UTC](https://discourse.julialang.org/t/optimiser-to-get-the-best-selection-of-a-set-of-penalty-values/86376 "2022-08-26T23:48:31Z")

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I have an optimisation model in Julia using Jump model and Cbc optimiser. The model is highly dependent on the initial inputs. What will be best method to select the initial input such that, the error penalty in the orig…

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## [Help me with Julia/R comparison project, how to plot US county maps in Plots/StatsPlots (or what's best alternative)?](https://discourse.julialang.org/t/help-me-with-julia-r-comparison-project-how-to-plot-us-county-maps-in-plots-statsplots-or-whats-best-alternative/75686)

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**Author:** [@dlakelan](https://discourse.julialang.org/u/dlakelan)\
**Replies:** 18\
**Last updated:** [August 26, 2022, 10:23pm UTC](https://discourse.julialang.org/t/help-me-with-julia-r-comparison-project-how-to-plot-us-county-maps-in-plots-statsplots-or-whats-best-alternative/75686 "2022-08-26T22:23:52Z")

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I’m working with Phil Price over at Andrew Gelman’s blog https://statmodeling.stat.columbia.edu/ to do a comparison between using R and using Julia for basic data analysis stuff. We’ve got a few simple tasks and are imp…

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## [Automated distribution fitting](https://discourse.julialang.org/t/automated-distribution-fitting/30161)

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**Author:** [@mike\_k](https://discourse.julialang.org/u/mike_k)\
**Replies:** 11\
**Last updated:** [August 26, 2022, 9:43pm UTC](https://discourse.julialang.org/t/automated-distribution-fitting/30161 "2022-08-26T21:43:33Z")

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Dear community, I am not an expert in statistics, so maybe this question is a bit naive. I have a data vector with ~10^6 entries (between \[0,1\]) and want to identify a distribution which fits best to that data. I wonder…

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## [Obtaining sub-optimal results from the model when the time limit is reached](https://discourse.julialang.org/t/obtaining-sub-optimal-results-from-the-model-when-the-time-limit-is-reached/85635)

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**Author:** [@AAAG](https://discourse.julialang.org/u/AAAG)\
**Replies:** 11\
**Last updated:** [August 26, 2022, 8:47pm UTC](https://discourse.julialang.org/t/obtaining-sub-optimal-results-from-the-model-when-the-time-limit-is-reached/85635 "2022-08-26T20:47:02Z")

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Hi, I am working on a model that includes both linear and non-linear constraints. I am using Ipopt and Juniper solvers for my model. What I am trying to do is to limit the time of the model and obtain the sub-optimal s…

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## [Symbolics: Extend a rule to a sum with multiple terms](https://discourse.julialang.org/t/symbolics-extend-a-rule-to-a-sum-with-multiple-terms/86384)

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**Author:** [@qwerty](https://discourse.julialang.org/u/qwerty)\
**Replies:** 2\
**Last updated:** [August 26, 2022, 8:22pm UTC](https://discourse.julialang.org/t/symbolics-extend-a-rule-to-a-sum-with-multiple-terms/86384 "2022-08-26T20:22:38Z")

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I have this: @syms commutator(a, b) myRule = @rule commutator((~a)+(~b), ~c) =\> commutator(~a, ~c) + commutator(~b, ~c) how can I extend the rule to get: myRule\_ = @rule commutator((~a)+(~b)+(~d), ~c) =\> commutator(~a…

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## [Commit to a common syntax for accessing additional index mapping information on axes](https://discourse.julialang.org/t/commit-to-a-common-syntax-for-accessing-additional-index-mapping-information-on-axes/84988)

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**Author:** [@Zach\_Christensen](https://discourse.julialang.org/u/Zach_Christensen)\
**Replies:** 75\
**Last updated:** [August 26, 2022, 7:12pm UTC](https://discourse.julialang.org/t/commit-to-a-common-syntax-for-accessing-additional-index-mapping-information-on-axes/84988 "2022-08-26T19:12:54Z")

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If you use AxisArrays.jl it’s axisvalues(data, dim), if you use AxisKeys.jl it’s called axiskeys(data, dim), if you use DimensionalData.jl it’s dims(data, dim).val, if you use NamedArrays.jl it’s \`names(data, dim). Whate…

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## [State of machine learning in Julia](https://discourse.julialang.org/t/state-of-machine-learning-in-julia/74385)

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**Author:** [@sethaxen](https://discourse.julialang.org/u/sethaxen)\
**Replies:** 60\
**Last updated:** [August 26, 2022, 4:34pm UTC](https://discourse.julialang.org/t/state-of-machine-learning-in-julia/74385 "2022-08-26T16:34:27Z")

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After the Twitter space Q&A @logankilpatrick hosted yesterday on “The future of machine learning and why it looks a lot like Julia,” I thought it would be useful to accumulate some community responses to a few questions …

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## [MAP Optimization and RAM usage related to autodiff](https://discourse.julialang.org/t/map-optimization-and-ram-usage-related-to-autodiff/86388)

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**Author:** [@jweinstk](https://discourse.julialang.org/u/jweinstk)\
**Replies:** 0\
**Last updated:** [August 26, 2022, 2:28pm UTC](https://discourse.julialang.org/t/map-optimization-and-ram-usage-related-to-autodiff/86388 "2022-08-26T14:28:39Z")

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Hi there probabilistic programming folks - I’ve enjoyed reading the posts here and now have one of my own. I am trying to estimate the MAP of a multivariate linear model with a mixture model component using Turing (will …

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## [Order of rules in Symbolics / SymbolicUtils](https://discourse.julialang.org/t/order-of-rules-in-symbolics-symbolicutils/86383)

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**Author:** [@qwerty](https://discourse.julialang.org/u/qwerty)\
**Replies:** 1\
**Last updated:** [August 26, 2022, 1:50pm UTC](https://discourse.julialang.org/t/order-of-rules-in-symbolics-symbolicutils/86383 "2022-08-26T13:50:12Z")

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Does the order of the rules in Symbolics/SymbolicUtils matter when simplifying?

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## [Parameter Estimation of ODE system where the response variables are not the state variables](https://discourse.julialang.org/t/parameter-estimation-of-ode-system-where-the-response-variables-are-not-the-state-variables/86171)

<div class="topic-metadata">

**Author:** [@jonlym](https://discourse.julialang.org/u/jonlym)\
**Replies:** 8\
**Last updated:** [August 26, 2022, 12:46pm UTC](https://discourse.julialang.org/t/parameter-estimation-of-ode-system-where-the-response-variables-are-not-the-state-variables/86171 "2022-08-26T12:46:50Z")

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I am new to Julia and I would like to write a program to estimate the kinetic parameters for a chemical system. I am aware of Catalyst.jl but my work involves systems with complex geometries so I often have to modify my …

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