# Latest

**URL:** https://discourse.julialang.org/latest.md?page=1339

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

**Page:** 1340

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## [Memory usage data for getproperty function](https://discourse.julialang.org/t/memory-usage-data-for-getproperty-function/64139)

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**Author:** [@jsjie](https://discourse.julialang.org/u/jsjie)\
**Replies:** 3\
**Last updated:** [July 6, 2021, 10:56am UTC](https://discourse.julialang.org/t/memory-usage-data-for-getproperty-function/64139 "2021-07-06T10:56:09Z")

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I’m analysing memory usage as described in julia manual , and I found that getproperty functions seem to be related to large numbers. The following lines is taken from the result .mem file: - function Base.getp…

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## [Overloading ≫ yields ERROR: TypeError: non-boolean used in boolean context](https://discourse.julialang.org/t/overloading-yields-error-typeerror-non-boolean-used-in-boolean-context/64132)

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**Author:** [@schlichtanders](https://discourse.julialang.org/u/schlichtanders)\
**Replies:** 3\
**Last updated:** [July 6, 2021, 9:56am UTC](https://discourse.julialang.org/t/overloading-yields-error-typeerror-non-boolean-used-in-boolean-context/64132 "2021-07-06T09:56:07Z")

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Can anyone help why this weird error happens? (working on julia 1.6.1) julia\> a ≫ b = a + b ≫ (generic function with 1 method) julia\> (1 ≫ 2) ≫ 3 6 julia\> 1 ≫ (2 ≫ 3) 6 julia\> 1 ≫ 2 ≫ 3 ERROR: TypeError: non-b…

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## [@printf not consistent with C printf?](https://discourse.julialang.org/t/printf-not-consistent-with-c-printf/64136)

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**Author:** [@floswald](https://discourse.julialang.org/u/floswald)\
**Replies:** 3\
**Last updated:** [July 6, 2021, 9:32am UTC](https://discourse.julialang.org/t/printf-not-consistent-with-c-printf/64136 "2021-07-06T09:32:57Z")

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quick question about %02.3f format specifier - that should left pad zeros to the left of the comma sign, and have 3 digits afterwards, like here formatting - 'printf' with leading zeros in C - Stack Overflow julia\> @pri…

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## [Two Y-axis in PlotlyJS](https://discourse.julialang.org/t/two-y-axis-in-plotlyjs/62701)

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**Author:** [@VivMendes](https://discourse.julialang.org/u/VivMendes)\
**Replies:** 1\
**Last updated:** [July 6, 2021, 9:11am UTC](https://discourse.julialang.org/t/two-y-axis-in-plotlyjs/62701 "2021-07-06T09:11:28Z")

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Hi, I am trying to come up with a two yy-axis in a plot using PlotlyJS. I have tried many variations on the Plotly example (displayed below), but all the time, something comes out wrong. Help will be very much appreciat…

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## [Julia 1.6 UndefVarError: .. not defined](https://discourse.julialang.org/t/julia-1-6-undefvarerror-not-defined/64085)

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**Author:** [@reemmasoud123](https://discourse.julialang.org/u/reemmasoud123)\
**Replies:** 5\
**Last updated:** [July 6, 2021, 8:56am UTC](https://discourse.julialang.org/t/julia-1-6-undefvarerror-not-defined/64085 "2021-07-06T08:56:00Z")

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I just downloaded Julia 1.6 and the syntax: \[-1. .1\] that expresses a range of numbers which used to work in Julia 1.5 no longer works. Does anyone know what the latest syntax for “. .” is? I need it as I am using the…

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## [Overlap scatter plot and curve plot for data fitting](https://discourse.julialang.org/t/overlap-scatter-plot-and-curve-plot-for-data-fitting/64128)

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**Author:** [@minhnguyen](https://discourse.julialang.org/u/minhnguyen)\
**Replies:** 1\
**Last updated:** [July 6, 2021, 5:45am UTC](https://discourse.julialang.org/t/overlap-scatter-plot-and-curve-plot-for-data-fitting/64128 "2021-07-06T05:45:53Z")

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Hi everyone, I’m trying to do math modeling based on a differential equation. I’m figuring out the parameters that make the graph matched the supported data. In order to see the fitness, I’d like to do overlapping graph…

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## [How do I watch JuliaCon 2021, if I missed it?](https://discourse.julialang.org/t/how-do-i-watch-juliacon-2021-if-i-missed-it/64126)

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**Author:** [@development\_mentor](https://discourse.julialang.org/u/development_mentor)\
**Replies:** 4\
**Last updated:** [July 6, 2021, 5:18am UTC](https://discourse.julialang.org/t/how-do-i-watch-juliacon-2021-if-i-missed-it/64126 "2021-07-06T05:18:31Z")

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I went with my family on holiday and couldn’t watch JuliaCon 2021. Is there a way to watch it now, or will it come on youtube?, Thanks!

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## [Cannot run ReinforcementLearning#master](https://discourse.julialang.org/t/cannot-run-reinforcementlearning-master/64050)

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**Author:** [@filchristou](https://discourse.julialang.org/u/filchristou)\
**Replies:** 1\
**Last updated:** [July 6, 2021, 4:49am UTC](https://discourse.julialang.org/t/cannot-run-reinforcementlearning-master/64050 "2021-07-06T04:49:45Z")

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Hi. Running pkg\> add ReinforcementLearning works as it should. Then, I wanted to try download the latest master branch from the git repo, as it also looks that the docu Tutorial · ReinforcementLearning.jl is based on thi…

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## [Interested for co-authoring a book titled "ML in Julia ecosystem"](https://discourse.julialang.org/t/interested-for-co-authoring-a-book-titled-ml-in-julia-ecosystem/64125)

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**Author:** [@Naba7](https://discourse.julialang.org/u/Naba7)\
**Replies:** 0\
**Last updated:** [July 6, 2021, 4:39am UTC](https://discourse.julialang.org/t/interested-for-co-authoring-a-book-titled-ml-in-julia-ecosystem/64125 "2021-07-06T04:39:41Z")

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I have been asked by Packt Publishing to author a book titled “ML in Julia ecosystem”. The outline is almost finished and I will be sending a final draft by this week. The Edboard team of Packt are asking for a co-author…

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## [Using functors for sparse Jacobian evaluations](https://discourse.julialang.org/t/using-functors-for-sparse-jacobian-evaluations/64111)

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**Author:** [@jdlara-berkeley](https://discourse.julialang.org/u/jdlara-berkeley)\
**Replies:** 2\
**Last updated:** [July 6, 2021, 12:13am UTC](https://discourse.julialang.org/t/using-functors-for-sparse-jacobian-evaluations/64111 "2021-07-06T00:13:38Z")

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I am trying to use ForwardDiff to calculate the Jacobian of a function so that I can reuse the resulting Jacobian function and use it as an input for several packages. For instance, pass it to NLsolve and later use it in…

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## [Developing a Beginner's Roadmap to Learn Julia High Performance Computing for Data Science](https://discourse.julialang.org/t/developing-a-beginners-roadmap-to-learn-julia-high-performance-computing-for-data-science/63970)

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**Author:** [@TheCedarPrince](https://discourse.julialang.org/u/TheCedarPrince)\
**Replies:** 30\
**Last updated:** [July 5, 2021, 11:53pm UTC](https://discourse.julialang.org/t/developing-a-beginners-roadmap-to-learn-julia-high-performance-computing-for-data-science/63970 "2021-07-05T23:53:19Z")

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Hi all :wave: Hope you are doing well! In alignment with both my professional and personal interests, I am slowly starting to turn my attention to the domain of High Performance Computing for the purposes of: Designin…

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## [Array indexing](https://discourse.julialang.org/t/array-indexing/64095)

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**Author:** [@Marcell\_Havlik](https://discourse.julialang.org/u/Marcell_Havlik)\
**Replies:** 7\
**Last updated:** [July 5, 2021, 10:43pm UTC](https://discourse.julialang.org/t/array-indexing/64095 "2021-07-05T22:43:14Z")

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Hey Julianners, Are there a way to ha a syntax like this: arrofarr = \[randn(2,4) for \_ in 1:10\] arrofarr\[7:end\]\[1:2,3:end\] # would select a \[4\] x \[2,2\] dim array. Is this possible? It would be really clean and it coul…

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## [Recent publications of Julia packages for Power Systems modeling](https://discourse.julialang.org/t/recent-publications-of-julia-packages-for-power-systems-modeling/64114)

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**Author:** [@jdlara-berkeley](https://discourse.julialang.org/u/jdlara-berkeley)\
**Replies:** 0\
**Last updated:** [July 5, 2021, 10:36pm UTC](https://discourse.julialang.org/t/recent-publications-of-julia-packages-for-power-systems-modeling/64114 "2021-07-05T22:36:05Z")

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For all the users interested in Power system modeling, I would like to share two recent publications about the packages we have been developing in Julia. PowerSystems.jl provides data structures to model power systems w…

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## [ForwardDiff.derivative! of inplace functions](https://discourse.julialang.org/t/forwarddiff-derivative-of-inplace-functions/54014)

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**Author:** [@jokasimr](https://discourse.julialang.org/u/jokasimr)\
**Replies:** 1\
**Last updated:** [July 5, 2021, 10:17pm UTC](https://discourse.julialang.org/t/forwarddiff-derivative-of-inplace-functions/54014 "2021-07-05T22:17:43Z")

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I’m learning how to use the FiniteDifference.jl package without allocating, and I want to implement a function for doing Jacobian vector products inplace. :slight\_smile: The goal is to accomplish the same as jvp\_finite…

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## [Learning Epidemic Model With Neural Differential Equations](https://discourse.julialang.org/t/learning-epidemic-model-with-neural-differential-equations/63386)

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**Author:** [@bkuwahara](https://discourse.julialang.org/u/bkuwahara)\
**Replies:** 5\
**Last updated:** [July 5, 2021, 9:26pm UTC](https://discourse.julialang.org/t/learning-epidemic-model-with-neural-differential-equations/63386 "2021-07-05T21:26:22Z")

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I’m trying to use neural networks with DiffEqFlux to learn an SIR model with vaccination dynamics. The equations for this model are function SIRx!(du, u, p, t) β, μ, γ, a, b = Float32.(\[280, 1/50, 365/22, 100, 0.05\]…

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## [\[ANN\] FIRLSFilterDesign.jl](https://discourse.julialang.org/t/ann-firlsfilterdesign-jl/59820)

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**Author:** [@LeoKoo](https://discourse.julialang.org/u/LeoKoo)\
**Replies:** 4\
**Last updated:** [July 5, 2021, 9:03pm UTC](https://discourse.julialang.org/t/ann-firlsfilterdesign-jl/59820 "2021-07-05T21:03:22Z")

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Hi everyone, I want to announce FIRLSFilterDesign.jl, which is a package that allows you to design linear phase Finite Impulse Response filters using weighted Least-Squares. It supports: All types of linear phase FIR…

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## [What is package that needs to be added to use SparseMatrix?](https://discourse.julialang.org/t/what-is-package-that-needs-to-be-added-to-use-sparsematrix/64105)

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**Author:** [@Amro](https://discourse.julialang.org/u/Amro)\
**Replies:** 2\
**Last updated:** [July 5, 2021, 8:51pm UTC](https://discourse.julialang.org/t/what-is-package-that-needs-to-be-added-to-use-sparsematrix/64105 "2021-07-05T20:51:44Z")

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Hello, I am trying to use the spzeros() function, but I couldnt know which package I need to install? Bests,

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## [Unable to use Flux](https://discourse.julialang.org/t/unable-to-use-flux/64077)

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**Author:** [@development\_mentor](https://discourse.julialang.org/u/development_mentor)\
**Replies:** 5\
**Last updated:** [July 5, 2021, 8:25pm UTC](https://discourse.julialang.org/t/unable-to-use-flux/64077 "2021-07-05T20:25:08Z")

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Hello, I’m trying to do reinforcement learning and deep learning with Julia. But can’t use Flux. I get an error: ┌ Info: Precompiling Flux \[587475ba-b771-5e3f-ad9e-33799f191a9c\] └ @ Base loading.jl:1317 ERROR: LoadError…

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## [How to get 'stable' URL for documentation?](https://discourse.julialang.org/t/how-to-get-stable-url-for-documentation/64030)

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**Author:** [@MattWillFlood](https://discourse.julialang.org/u/MattWillFlood)\
**Replies:** 6\
**Last updated:** [July 5, 2021, 8:19pm UTC](https://discourse.julialang.org/t/how-to-get-stable-url-for-documentation/64030 "2021-07-05T20:19:59Z")

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According to the documentation for Documenter.jl: Documentation built for a tag vX.Y.Z will be stored in a folder vX.Y.Z . Documentation built from the devbranch branch ( master by default) is stored in a folder deter…

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## [Unable to install JuliaPro on Ubuntu](https://discourse.julialang.org/t/unable-to-install-juliapro-on-ubuntu/64091)

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**Author:** [@Mahesh](https://discourse.julialang.org/u/Mahesh)\
**Replies:** 2\
**Last updated:** [July 5, 2021, 7:59pm UTC](https://discourse.julialang.org/t/unable-to-install-juliapro-on-ubuntu/64091 "2021-07-05T19:59:32Z")

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Hello Julia, I have tried installing Julia on my Ubuntu 20.04 LTS but could not install it. Your help is much appreciated. sudo yum -y install xclip && sudo yum -y install libXScrnSaver chmod 777 JuliaPro-1.5.4-1\_buil…

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## [Does Julia have tail call optimization?](https://discourse.julialang.org/t/does-julia-have-tail-call-optimization/64101)

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**Author:** [@purplishrock](https://discourse.julialang.org/u/purplishrock)\
**Replies:** 4\
**Last updated:** [July 5, 2021, 7:50pm UTC](https://discourse.julialang.org/t/does-julia-have-tail-call-optimization/64101 "2021-07-05T19:50:10Z")

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does Julia have tail call optimization ? or does a recursive function always overflow regardless of if you are careful to construct it in that fashion ?

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## [Having difficulty to produce a .pdf (but not .html) output using Weave.jl](https://discourse.julialang.org/t/having-difficulty-to-produce-a-pdf-but-not-html-output-using-weave-jl/64100)

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**Author:** [@quant-biologist](https://discourse.julialang.org/u/quant-biologist)\
**Replies:** 0\
**Last updated:** [July 5, 2021, 7:45pm UTC](https://discourse.julialang.org/t/having-difficulty-to-produce-a-pdf-but-not-html-output-using-weave-jl/64100 "2021-07-05T19:45:38Z")

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Good day, I am new to Julia, but really eager to learn. I am preparing a scientific manuscript and I would like to provide reproducible documents (i.e. Julia code) to publish on a GitHub repository. I have no problem us…

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## [My function for a struct complains access to undefined reference?](https://discourse.julialang.org/t/my-function-for-a-struct-complains-access-to-undefined-reference/64092)

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**Author:** [@EMCP](https://discourse.julialang.org/u/EMCP)\
**Replies:** 2\
**Last updated:** [July 5, 2021, 7:09pm UTC](https://discourse.julialang.org/t/my-function-for-a-struct-complains-access-to-undefined-reference/64092 "2021-07-05T19:09:32Z")

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I have 3 julialang files so far… and trying to get a working setup… but hit a snag … here’s my code dense\_layer.jl mutable struct LayerDense num\_inputs num\_neurons weights::Matrix{Float64} biases::Matri…

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## [Differential operators: curl div, grad, laplacian, partial derivatives with automatic differentiation](https://discourse.julialang.org/t/differential-operators-curl-div-grad-laplacian-partial-derivatives-with-automatic-differentiation/39375)

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**Author:** [@mleprovost](https://discourse.julialang.org/u/mleprovost)\
**Replies:** 9\
**Last updated:** [July 5, 2021, 7:21pm UTC](https://discourse.julialang.org/t/differential-operators-curl-div-grad-laplacian-partial-derivatives-with-automatic-differentiation/39375 "2021-07-05T19:21:52Z")

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Hello, Is there a package that implements the operators curl div, grad, laplacian, partial derivatives with automatic differentiation for scalar functions and vector fields?

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## [Closed Source Dependencies and Licenses from SAS](https://discourse.julialang.org/t/closed-source-dependencies-and-licenses-from-sas/64090)

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**Author:** [@nucklass](https://discourse.julialang.org/u/nucklass)\
**Replies:** 3\
**Last updated:** [July 5, 2021, 7:03pm UTC](https://discourse.julialang.org/t/closed-source-dependencies-and-licenses-from-sas/64090 "2021-07-05T19:03:00Z")

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Hoping some some more experienced devs could chime in. I’m looking to write a package for Julia to interface with SAS, akin to the saspy package SAS maintains. Long story short, the Julia package will need these four jar…

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## [Dot vs. array comprehension vs. loop](https://discourse.julialang.org/t/dot-vs-array-comprehension-vs-loop/64049)

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**Author:** [@pmlo](https://discourse.julialang.org/u/pmlo)\
**Replies:** 4\
**Last updated:** [July 4, 2021, 10:56pm UTC](https://discourse.julialang.org/t/dot-vs-array-comprehension-vs-loop/64049 "2021-07-04T22:56:10Z")

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Hello! New Julia user here. Following this post, I try to learn the way to speed up sums / integrals. I am doing the following test: using BenchmarkTools xvec = range(0, 4, length=1000) function fdot() function …

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## [Announcing SubspaceInference.jl](https://discourse.julialang.org/t/announcing-subspaceinference-jl/64094)

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**Author:** [@Manu\_Francis](https://discourse.julialang.org/u/Manu_Francis)\
**Replies:** 0\
**Last updated:** [July 5, 2021, 6:01pm UTC](https://discourse.julialang.org/t/announcing-subspaceinference-jl/64094 "2021-07-05T18:01:11Z")

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I’m happy to announce SubspaceInference.jl , a fast implementation to generate uncertainties in Neural Networks and Neural ODE’s Scaling of Bayesian inference techniques to deep neural networks (Bayesian Neural Networks…

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## [Question in Packages.ipynb](https://discourse.julialang.org/t/question-in-packages-ipynb/64093)

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**Author:** [@Paresh](https://discourse.julialang.org/u/Paresh)\
**Replies:** 1\
**Last updated:** [July 5, 2021, 6:02pm UTC](https://discourse.julialang.org/t/question-in-packages-ipynb/64093 "2021-07-05T18:02:03Z")

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Hello, How do we see the environment similar to (Introduction to Julia) pkg\> on the Terminal. Please help. Thank you.

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## [JuliaMunich Share&Code: Probabilistic Modelling with Turing.jl](https://discourse.julialang.org/t/juliamunich-share-code-probabilistic-modelling-with-turing-jl/62832)

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**Author:** [@schlichtanders](https://discourse.julialang.org/u/schlichtanders)\
**Replies:** 4\
**Last updated:** [July 5, 2021, 4:19pm UTC](https://discourse.julialang.org/t/juliamunich-share-code-probabilistic-modelling-with-turing-jl/62832 "2021-07-05T16:19:31Z")

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Time: 05. July 2021 at 18:30 Location: online, organized via Login to Meetup | Meetup Probabilistic programming is my favourite strength of the Julia language. I am glad to welcome @devmotion David Widmann, an active d…

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## [ForwardDiff caches usage](https://discourse.julialang.org/t/forwarddiff-caches-usage/64058)

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**Author:** [@jdlara-berkeley](https://discourse.julialang.org/u/jdlara-berkeley)\
**Replies:** 5\
**Last updated:** [July 5, 2021, 4:07pm UTC](https://discourse.julialang.org/t/forwarddiff-caches-usage/64058 "2021-07-05T16:07:06Z")

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I have been trying to implement a cache correctly for ForwardDiff similar to DiffEqCache without too much success. My final objective is to have a Jacobian function of the system that we can reuse in multiple steps sinc…

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