# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=421

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**Page:** 422

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## [Examples with atomic operations using CUDA.jl](https://discourse.julialang.org/t/examples-with-atomic-operations-using-cuda-jl/46084)

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**Author:** [@duanestorti](https://discourse.julialang.org/u/duanestorti)\
**Replies:** 6\
**Last updated:** [September 15, 2020, 2:31pm UTC](https://discourse.julialang.org/t/examples-with-atomic-operations-using-cuda-jl/46084 "2020-09-15T14:31:44Z")

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Can anyone point me to examples that include atomic operations using CUDA.jl? I am having some issues trying to figure out the syntax for pointers, and examples would be helpful.

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## [Adjusting markers in legend](https://discourse.julialang.org/t/adjusting-markers-in-legend/38042)

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**Author:** [@jamblejoe](https://discourse.julialang.org/u/jamblejoe)\
**Replies:** 4\
**Last updated:** [September 15, 2020, 11:40am UTC](https://discourse.julialang.org/t/adjusting-markers-in-legend/38042 "2020-09-15T11:40:02Z")

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Hi, I would like to adjust marker settings in the legend, e.g. size and strokewidth, ideally with the pyplot backend. In the following minimal working example I would like the markers in the legend to be the same as in …

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## [Condition in @objective](https://discourse.julialang.org/t/condition-in-objective/46526)

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**Author:** [@sogrbilja](https://discourse.julialang.org/u/sogrbilja)\
**Replies:** 5\
**Last updated:** [September 15, 2020, 10:54am UTC](https://discourse.julialang.org/t/condition-in-objective/46526 "2020-09-15T10:54:45Z")

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I want to set an if statement in @objective macro. This is how it looks like now: @variable(premex, PRODAMOUNT\[op\_k in keys(\_ORDER\_PRODUCTs\_ALL), u\_k in keys(UNITS), t in TIME\], Int, lower\_bound = 0) @o…

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## [Zygote unexpected broadcasting](https://discourse.julialang.org/t/zygote-unexpected-broadcasting/46476)

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**Author:** [@merckxiaan](https://discourse.julialang.org/u/merckxiaan)\
**Replies:** 1\
**Last updated:** [September 15, 2020, 9:47am UTC](https://discourse.julialang.org/t/zygote-unexpected-broadcasting/46476 "2020-09-15T09:47:48Z")

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This is a MWE for a problem i’m having, I’ve adapted matrix multiplication to accept trans arguments telling whether the matrix is to be transposed. As for the adjoint definition, I looked at NNlib.batched\_mul When I t…

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## [There is nothing in html doc exported from Pluto notebook](https://discourse.julialang.org/t/there-is-nothing-in-html-doc-exported-from-pluto-notebook/46621)

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**Author:** [@Sijun](https://discourse.julialang.org/u/Sijun)\
**Replies:** 2\
**Last updated:** [September 15, 2020, 8:37am UTC](https://discourse.julialang.org/t/there-is-nothing-in-html-doc-exported-from-pluto-notebook/46621 "2020-09-15T08:37:25Z")

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Pluto is really a wonderful package; Overall look and feel of document is great, cells are very responsive while I edit, powerful @bind feature, etc. Now I want to export to html. But when I clicked on “export static …

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## [Performance of optimization problem in a loop](https://discourse.julialang.org/t/performance-of-optimization-problem-in-a-loop/46374)

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**Author:** [@Oliver\_Lylloff](https://discourse.julialang.org/u/Oliver_Lylloff)\
**Replies:** 14\
**Last updated:** [September 15, 2020, 7:30am UTC](https://discourse.julialang.org/t/performance-of-optimization-problem-in-a-loop/46374 "2020-09-15T07:30:37Z")

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Hello. I’m trying to improve the performance of an optimization problem. I have a Hermitian matrix and want to minimize the diagonal terms while keeping the matrix positive semidefinite. Given a matrix S, \\text{minimi…

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## [Triple buffering](https://discourse.julialang.org/t/triple-buffering/46616)

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**Author:** [@cscherrer](https://discourse.julialang.org/u/cscherrer)\
**Replies:** 2\
**Last updated:** [September 15, 2020, 2:52am UTC](https://discourse.julialang.org/t/triple-buffering/46616 "2020-09-15T02:52:41Z")

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Hi, I’m curious if anyone has tried triple buffering. This is a generally useful framework, but I’m specifically thinking allocation-free MCMC (or maybe more accurately, iteration-independent allocation count). I think …

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## [Getting off the ground with Gen](https://discourse.julialang.org/t/getting-off-the-ground-with-gen/44211)

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**Author:** [@terdmann](https://discourse.julialang.org/u/terdmann)\
**Replies:** 1\
**Last updated:** [September 14, 2020, 7:13pm UTC](https://discourse.julialang.org/t/getting-off-the-ground-with-gen/44211 "2020-09-14T19:13:48Z")

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I am really interested in Gen.jl, but am somewhat confused from the documentation. That is, I could not find any example of the functionality I’m trying to use. Can someone help me with the first steps? My first questio…

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## [Calling a CUDA kernel in an external library](https://discourse.julialang.org/t/calling-a-cuda-kernel-in-an-external-library/46505)

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**Author:** [@Niclas\_Wiberg](https://discourse.julialang.org/u/Niclas_Wiberg)\
**Replies:** 6\
**Last updated:** [September 14, 2020, 5:48pm UTC](https://discourse.julialang.org/t/calling-a-cuda-kernel-in-an-external-library/46505 "2020-09-14T17:48:44Z")

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Is it possible to call a precompiled CUDA kernel from Julia? I am writing CUDA kernels in C++ and compiling with nvcc, for use in a C++ application. I use Julia to test the code. Currently I write host-side wrapping fun…

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## [Adjointing around Mutating Part](https://discourse.julialang.org/t/adjointing-around-mutating-part/46582)

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**Author:** [@rakeshvar](https://discourse.julialang.org/u/rakeshvar)\
**Replies:** 0\
**Last updated:** [September 14, 2020, 11:42am UTC](https://discourse.julialang.org/t/adjointing-around-mutating-part/46582 "2020-09-14T11:42:38Z")

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I have the following toy problem that imitates my more complex problem. (A follow up from this question.) function triangulate(x::Matrix{T}) where T m, n = size(x) a = x\[:,1\] .\* \[1; zeros(T, m-1)\] for i in 2…

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## [Recovering parameters from product of two truncated normal distributions](https://discourse.julialang.org/t/recovering-parameters-from-product-of-two-truncated-normal-distributions/46577)

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**Author:** [@Libbum](https://discourse.julialang.org/u/Libbum)\
**Replies:** 2\
**Last updated:** [September 14, 2020, 10:02am UTC](https://discourse.julialang.org/t/recovering-parameters-from-product-of-two-truncated-normal-distributions/46577 "2020-09-14T10:02:09Z")

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Hi all, I’ve been thrown into the deep end with some stats, and don’t know enough about the Julia ecosystem around my problem to know if I’m doing this right. For the moment, this is an example of what I’m doing: an in…

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## [DiffEqParamEstim TypeAssert problem with forward AD](https://discourse.julialang.org/t/diffeqparamestim-typeassert-problem-with-forward-ad/46553)

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**Author:** [@moesphere](https://discourse.julialang.org/u/moesphere)\
**Replies:** 3\
**Last updated:** [September 14, 2020, 7:08am UTC](https://discourse.julialang.org/t/diffeqparamestim-typeassert-problem-with-forward-ad/46553 "2020-09-14T07:08:00Z")

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I am getting a typeassert problem when I use the build\_objective\_function in combination with forward AD. Optimization is via Optim. It works if I use finite differencing or e.g. Tsit5() instead of Rosenbrock23() as the …

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## [Making a collection of JuMP models using pmap](https://discourse.julialang.org/t/making-a-collection-of-jump-models-using-pmap/46530)

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**Author:** [@adow031](https://discourse.julialang.org/u/adow031)\
**Replies:** 4\
**Last updated:** [September 13, 2020, 10:26pm UTC](https://discourse.julialang.org/t/making-a-collection-of-jump-models-using-pmap/46530 "2020-09-13T22:26:28Z")

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I’m trying to create a number of JuMP models in parallel using pmap, and while the basic functionality of this is working fine, my implementation stores some variables and expressions in the ext field of the JuMP.Model. …

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## [Broadcasting in loss function for RNN with timeseries](https://discourse.julialang.org/t/broadcasting-in-loss-function-for-rnn-with-timeseries/44526)

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**Author:** [@raoulg](https://discourse.julialang.org/u/raoulg)\
**Replies:** 4\
**Last updated:** [September 12, 2020, 10:33pm UTC](https://discourse.julialang.org/t/broadcasting-in-loss-function-for-rnn-with-timeseries/44526 "2020-09-12T22:33:55Z")

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I’m trying to get an RNN to work with timeseries and I don’t understand why things don’t work as expected. I found a workaround, but it just seems to be too complicated. My data are sequences of 29 observations, and I h…

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## [Create Running Total Columns in a Data Frame for Multiple Variables with Dynamic Column Name Creation](https://discourse.julialang.org/t/create-running-total-columns-in-a-data-frame-for-multiple-variables-with-dynamic-column-name-creation/46299)

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**Author:** [@clibassi](https://discourse.julialang.org/u/clibassi)\
**Replies:** 7\
**Last updated:** [September 12, 2020, 9:28pm UTC](https://discourse.julialang.org/t/create-running-total-columns-in-a-data-frame-for-multiple-variables-with-dynamic-column-name-creation/46299 "2020-09-12T21:28:31Z")

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I’ve got some sports data in a dataframe I’m playing with that has data on teams throughout a season and I have a number of performance measures I’d like to create cumulative sums for. I found some great suggestions for …

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## [JuMP constraint MethodError: no method matching isless(::Int64, ::VariableRef)](https://discourse.julialang.org/t/jump-constraint-methoderror-no-method-matching-isless-int64-variableref/46498)

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**Author:** [@valenmgama](https://discourse.julialang.org/u/valenmgama)\
**Replies:** 3\
**Last updated:** [September 12, 2020, 4:54pm UTC](https://discourse.julialang.org/t/jump-constraint-methoderror-no-method-matching-isless-int64-variableref/46498 "2020-09-12T16:54:47Z")

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Hey, I need your help! What I am basically trying is to add a constraint to a JuMP matrix variable that no more than one element of a row can be a value larger than 0. In other words only 1 element in the row can be a …

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## [Display an RGB array with Gtk.jl](https://discourse.julialang.org/t/display-an-rgb-array-with-gtk-jl/46506)

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**Author:** [@noroskir](https://discourse.julialang.org/u/noroskir)\
**Replies:** 2\
**Last updated:** [September 12, 2020, 3:12pm UTC](https://discourse.julialang.org/t/display-an-rgb-array-with-gtk-jl/46506 "2020-09-12T15:12:33Z")

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Hi there! I have an image as a 3dim RGB array Array{Int32, (width, height, 3)} and I want to render it with Gtk.jl. I have not yet found a description on how to do this. Can anyone help ? Thanks :slight\_smile:

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## [Suggestions for playing music from real-time data generated in Julia](https://discourse.julialang.org/t/suggestions-for-playing-music-from-real-time-data-generated-in-julia/46448)

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**Author:** [@Benny](https://discourse.julialang.org/u/Benny)\
**Replies:** 4\
**Last updated:** [September 12, 2020, 1:59pm UTC](https://discourse.julialang.org/t/suggestions-for-playing-music-from-real-time-data-generated-in-julia/46448 "2020-09-12T13:59:21Z")

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A little project I have in mind requires making data in real time (well, maybe 100 times a second at most) that is used to output music in real time. Details are scant because I haven’t really done anything yet, I’m tryi…

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## [Certain callback does not seem to have an effect when solving JumpProblem](https://discourse.julialang.org/t/certain-callback-does-not-seem-to-have-an-effect-when-solving-jumpproblem/46415)

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**Author:** [@Torkel](https://discourse.julialang.org/u/Torkel)\
**Replies:** 2\
**Last updated:** [September 12, 2020, 9:34am UTC](https://discourse.julialang.org/t/certain-callback-does-not-seem-to-have-an-effect-when-solving-jumpproblem/46415 "2020-09-12T09:34:41Z")

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I am trying to solve a jump problem. As a part of it, mid simulation, I change a parameter. This is basically an input being triggered into the system. This does not seem to have much effect though, and I am unsure why: …

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## [Smoothing Splines with Optimized Unequal Knot Spacing](https://discourse.julialang.org/t/smoothing-splines-with-optimized-unequal-knot-spacing/46418)

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**Author:** [@Nathan\_Boyer](https://discourse.julialang.org/u/Nathan_Boyer)\
**Replies:** 1\
**Last updated:** [September 12, 2020, 7:45am UTC](https://discourse.julialang.org/t/smoothing-splines-with-optimized-unequal-knot-spacing/46418 "2020-09-12T07:45:19Z")

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I have some (x,y) data with equally-spaced x’s. I would like to smooth the data using (up to) 4 cubic splines and obtain the equations for each spline. I would like the knots connecting the splines to move to an optimal …

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## [GLMakie complains about missing OpenGl, which is there](https://discourse.julialang.org/t/glmakie-complains-about-missing-opengl-which-is-there/29582)

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**Author:** [@zweiglimmergneis](https://discourse.julialang.org/u/zweiglimmergneis)\
**Replies:** 6\
**Last updated:** [September 11, 2020, 9:20pm UTC](https://discourse.julialang.org/t/glmakie-complains-about-missing-opengl-which-is-there/29582 "2020-09-11T21:20:38Z")

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This might be a OS-problem (fedora 30), but I couldn’t find useful info elsewhere, so I post the problem here. build GLMakie issues an Error: (v1.2) pkg\> build GLMakie Building Conda ───────────→ \`~/.julia/package…

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## [Impose initialization adn normalization on layers in Flux](https://discourse.julialang.org/t/impose-initialization-adn-normalization-on-layers-in-flux/23921)

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**Author:** [@stefesse](https://discourse.julialang.org/u/stefesse)\
**Replies:** 2\
**Last updated:** [September 11, 2020, 8:48pm UTC](https://discourse.julialang.org/t/impose-initialization-adn-normalization-on-layers-in-flux/23921 "2020-09-11T20:48:35Z")

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Hi all, I am constructing a simple perceptron with Flux, something like: y = W\*x + b. To do so I simply use: model = Dense(N,1,nonlinearity); What I do not understand is: How can I impose the initial value for the ma…

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## [Neural ODE fitting really slow](https://discourse.julialang.org/t/neural-ode-fitting-really-slow/45516)

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**Author:** [@vaglino](https://discourse.julialang.org/u/vaglino)\
**Replies:** 13\
**Last updated:** [September 11, 2020, 6:55pm UTC](https://discourse.julialang.org/t/neural-ode-fitting-really-slow/45516 "2020-09-11T18:55:32Z")

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I’m trying to fit this simple neural ODE, first with adam then bfgs, but the performance is extremely slow (about 15 minutes for 100 adams iterations). I am basing the code on the SciML talk from JuliaCon 2020. When I ti…

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## [Local installation of CUDA toolkit](https://discourse.julialang.org/t/local-installation-of-cuda-toolkit/46463)

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**Author:** [@DanaGalizia](https://discourse.julialang.org/u/DanaGalizia)\
**Replies:** 5\
**Last updated:** [September 11, 2020, 5:49pm UTC](https://discourse.julialang.org/t/local-installation-of-cuda-toolkit/46463 "2020-09-11T17:49:50Z")

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Hi, I’m trying to add the Cuda.jl package using a local installation of the CUDA toolkit. In the installation guide, it says You might want to disallow use of artifacts, e.g., because an optimized CUDA installation is …

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## [How to get/set constraint names?](https://discourse.julialang.org/t/how-to-get-set-constraint-names/46411)

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**Author:** [@vattyamv](https://discourse.julialang.org/u/vattyamv)\
**Replies:** 4\
**Last updated:** [September 11, 2020, 4:32pm UTC](https://discourse.julialang.org/t/how-to-get-set-constraint-names/46411 "2020-09-11T16:32:16Z")

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Hi, I am trying to set and get constraint names but am running into some errors. I originally built the model without naming the constraints but now I want to name them. Take for example, for i in 1:timerange @const…

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## [Hierarchical quadtree for fast mutipole method](https://discourse.julialang.org/t/hierarchical-quadtree-for-fast-mutipole-method/46350)

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**Author:** [@mleprovost](https://discourse.julialang.org/u/mleprovost)\
**Replies:** 3\
**Last updated:** [September 11, 2020, 3:43pm UTC](https://discourse.julialang.org/t/hierarchical-quadtree-for-fast-mutipole-method/46350 "2020-09-11T15:43:41Z")

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Hello, Is there a package that constructs a hierarchical quadtree given a set of non-uniform points in 2D? I would like to play around with fast multipole methods.

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## [Training a simple linear model in Flux](https://discourse.julialang.org/t/training-a-simple-linear-model-in-flux/24741)

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**Author:** [@robsmith11](https://discourse.julialang.org/u/robsmith11)\
**Replies:** 4\
**Last updated:** [September 11, 2020, 3:20pm UTC](https://discourse.julialang.org/t/training-a-simple-linear-model-in-flux/24741 "2020-09-11T15:20:10Z")

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I’m trying to get started with Flux, but finding the documentation a bit lacking in regards to explaining the basic functionality. For example, how would I train the following linear model with a single scalar parameter…

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## [R's pairs scatter plot in Julia](https://discourse.julialang.org/t/rs-pairs-scatter-plot-in-julia/46254)

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**Author:** [@maxpiot](https://discourse.julialang.org/u/maxpiot)\
**Replies:** 2\
**Last updated:** [September 11, 2020, 1:35pm UTC](https://discourse.julialang.org/t/rs-pairs-scatter-plot-in-julia/46254 "2020-09-11T13:35:29Z")

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Hi all, I’m looking for a convenient way of recreating the R’s pairwise scatter plots (Scatter Plot Matrices - R Base Graphs - Easy Guides - Wiki - STHDA) in Julia. I’ve come across the corrplot function in the StatsPl…

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## [Callback problem with DifferentialEquations](https://discourse.julialang.org/t/callback-problem-with-differentialequations/46057)

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**Author:** [@moesphere](https://discourse.julialang.org/u/moesphere)\
**Replies:** 10\
**Last updated:** [September 11, 2020, 12:40pm UTC](https://discourse.julialang.org/t/callback-problem-with-differentialequations/46057 "2020-09-11T12:40:24Z")

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I am stuck with a problem considering a SavingCallback from the DifferentialEquations suite. I could not create a MWE, thus I will explain the problem. I have an ODEProblem where I use a SavingCallback for the calculat…

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## [How to find the number of non-zeros weights needed to minimise the distance between a weighted sum and a population](https://discourse.julialang.org/t/how-to-find-the-number-of-non-zeros-weights-needed-to-minimise-the-distance-between-a-weighted-sum-and-a-population/46442)

<div class="topic-metadata">

**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 1\
**Last updated:** [September 11, 2020, 11:36am UTC](https://discourse.julialang.org/t/how-to-find-the-number-of-non-zeros-weights-needed-to-minimise-the-distance-between-a-weighted-sum-and-a-population/46442 "2020-09-11T11:36:35Z")

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Hello, I need to use some individual elements (x\_n, in my application agricultural farms of which I know every details) as building blocks to reconstruct an observed aggregate V\_d \>=0 for the d dimensions (in my applica…

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