# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=376

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**Page:** 377

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## [Using Gurobi with PowerModels](https://discourse.julialang.org/t/using-gurobi-with-powermodels/58688)

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**Author:** [@aaldik](https://discourse.julialang.org/u/aaldik)\
**Replies:** 1\
**Last updated:** [April 6, 2021, 7:28pm UTC](https://discourse.julialang.org/t/using-gurobi-with-powermodels/58688 "2021-04-06T19:28:35Z")

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Dears How to use Gurobi to solve optimization problems for PowerModels? Regards

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## [Type unstability with container generation in JuMP](https://discourse.julialang.org/t/type-unstability-with-container-generation-in-jump/58433)

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**Author:** [@etienne\_dg](https://discourse.julialang.org/u/etienne_dg)\
**Replies:** 4\
**Last updated:** [April 6, 2021, 5:55pm UTC](https://discourse.julialang.org/t/type-unstability-with-container-generation-in-jump/58433 "2021-04-06T17:55:24Z")

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Hi, julia\> model = Model(Gurobi.Optimizer) julia\> @variable(model, a\[x in 1:10; x \< 5\], Bin) JuMP.Containers.SparseAxisArray{VariableRef, 1, Tuple{Int64}} with 4 entries: julia\> @variable(model, b\[x in 1:10; x \> 15\], …

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## [Stochastic simulation error](https://discourse.julialang.org/t/stochastic-simulation-error/58692)

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**Author:** [@jailton](https://discourse.julialang.org/u/jailton)\
**Replies:** 1\
**Last updated:** [April 6, 2021, 4:32pm UTC](https://discourse.julialang.org/t/stochastic-simulation-error/58692 "2021-04-06T16:32:47Z")

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Hello, I am newbie in Julia, trying to run a MCMC algorithm, but I getting some complaints about the parameters of the gamma distribution (which are supposed to be \> 0), but they are, so I don’t understand this complain…

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## [Folder picker](https://discourse.julialang.org/t/folder-picker/58679)

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**Author:** [@saraflgarcia](https://discourse.julialang.org/u/saraflgarcia)\
**Replies:** 0\
**Last updated:** [April 6, 2021, 11:44am UTC](https://discourse.julialang.org/t/folder-picker/58679 "2021-04-06T11:44:11Z")

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Hi everyone, I’m using the Interact package. How can I make a widget to pick a folder (like the filepicker but for folders)? Thank you so much, Sara

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## [Making a PD Controller Component in ModelingToolkit.jl](https://discourse.julialang.org/t/making-a-pd-controller-component-in-modelingtoolkit-jl/58509)

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**Author:** [@Dhruva2](https://discourse.julialang.org/u/Dhruva2)\
**Replies:** 28\
**Last updated:** [April 6, 2021, 10:10am UTC](https://discourse.julialang.org/t/making-a-pd-controller-component-in-modelingtoolkit-jl/58509 "2021-04-06T10:10:32Z")

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If I were to make a PD controller component, I’d probably do something like this: using ModelingToolkit function PD\_controller(Pgain, Dgain, num\_inputs; name=:pd) @parameters t D = Differential(t) @variables…

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## [Ternary diagrams and surfaces on non-rectangular grids](https://discourse.julialang.org/t/ternary-diagrams-and-surfaces-on-non-rectangular-grids/43423)

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**Author:** [@SEA](https://discourse.julialang.org/u/SEA)\
**Replies:** 12\
**Last updated:** [April 6, 2021, 12:46am UTC](https://discourse.julialang.org/t/ternary-diagrams-and-surfaces-on-non-rectangular-grids/43423 "2021-04-06T00:46:05Z")

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I would like to plot a surface on a triangular domain. Is there a Julia project which can plot ternary diagrams, akin to this code?

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## [Lazy constraint callback issue with GLPK](https://discourse.julialang.org/t/lazy-constraint-callback-issue-with-glpk/58345)

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**Author:** [@manoj.centura](https://discourse.julialang.org/u/manoj.centura)\
**Replies:** 5\
**Last updated:** [April 5, 2021, 11:28pm UTC](https://discourse.julialang.org/t/lazy-constraint-callback-issue-with-glpk/58345 "2021-04-05T23:28:07Z")

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Hi , The callback is not working in GLPK. The below code is working in fine Gurobi. using JuMP, Gurobi,MathOptInterface,GLPK model = Model(Gurobi.Optimizer) set\_optimizer\_attribute(model, "OutputFlag", 0) …

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## [Finite Element Assembly using map over elements](https://discourse.julialang.org/t/finite-element-assembly-using-map-over-elements/58576)

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**Author:** [@ziolai](https://discourse.julialang.org/u/ziolai)\
**Replies:** 6\
**Last updated:** [April 5, 2021, 9:24am UTC](https://discourse.julialang.org/t/finite-element-assembly-using-map-over-elements/58576 "2021-04-05T09:24:19Z")

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Hi, I am wondering whether the loop over the elements in a finite element assembly can be replace by a flavor of map over the list of elements. I am happy to consider the linear elements on a one-dimensional mesh to st…

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## [Design preconditioner for unconstrained optimization problem](https://discourse.julialang.org/t/design-preconditioner-for-unconstrained-optimization-problem/58650)

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**Author:** [@mleprovost](https://discourse.julialang.org/u/mleprovost)\
**Replies:** 0\
**Last updated:** [April 5, 2021, 10:35pm UTC](https://discourse.julialang.org/t/design-preconditioner-for-unconstrained-optimization-problem/58650 "2021-04-05T22:35:33Z")

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Hello, I am working on the greedy algorithm developed in Baptista et al. (https://arxiv.org/pdf/2009.10303.pdf) to approximate the components of a transport map S (aka normalizing flow) that pushes forward a target den…

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## [Obtaining Irreducible Inconsistent Subsystem (IIS) with JumP - Gurobi](https://discourse.julialang.org/t/obtaining-irreducible-inconsistent-subsystem-iis-with-jump-gurobi/58491)

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**Author:** [@priantop](https://discourse.julialang.org/u/priantop)\
**Replies:** 2\
**Last updated:** [April 5, 2021, 9:27pm UTC](https://discourse.julialang.org/t/obtaining-irreducible-inconsistent-subsystem-iis-with-jump-gurobi/58491 "2021-04-05T21:27:11Z")

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Hi, I am kind of new to Julia (+/- 3 months of usage) I am trying to find which constraints are members of IIS of an Infeasible or Unbounded optimisation problem. For example, I have the following script using JuMP, G…

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## [How to get ticks elapsed by CPLEX solver with JuMP?](https://discourse.julialang.org/t/how-to-get-ticks-elapsed-by-cplex-solver-with-jump/58619)

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**Author:** [@Antell](https://discourse.julialang.org/u/Antell)\
**Replies:** 1\
**Last updated:** [April 5, 2021, 4:04pm UTC](https://discourse.julialang.org/t/how-to-get-ticks-elapsed-by-cplex-solver-with-jump/58619 "2021-04-05T16:04:43Z")

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I would like to call the getDetTime function from IBM Documentation on a model, in order to get the amount of deterministic ticks that have elapsed during a call to optimize!. I cannot figure out how to use the new CPLEX…

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## [JuMP optimize! call will very rarely violate model's time limit parameters by huge factors?](https://discourse.julialang.org/t/jump-optimize-call-will-very-rarely-violate-models-time-limit-parameters-by-huge-factors/58061)

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**Author:** [@Antell](https://discourse.julialang.org/u/Antell)\
**Replies:** 18\
**Last updated:** [April 5, 2021, 2:50pm UTC](https://discourse.julialang.org/t/jump-optimize-call-will-very-rarely-violate-models-time-limit-parameters-by-huge-factors/58061 "2021-04-05T14:50:41Z")

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I am doing research that involves incrementally loosening the relative parameter setting of a MIPS optimizer, in order to enable faster termination. Normally, this strategy works quite well. However, very rarely a call t…

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## [How to fix Error: Method error: objects of type GenericAffExpr{Float64, VariableRef} are not callable](https://discourse.julialang.org/t/how-to-fix-error-method-error-objects-of-type-genericaffexpr-float64-variableref-are-not-callable/58495)

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**Author:** [@GraceMabele](https://discourse.julialang.org/u/GraceMabele)\
**Replies:** 3\
**Last updated:** [April 5, 2021, 12:40pm UTC](https://discourse.julialang.org/t/how-to-fix-error-method-error-objects-of-type-genericaffexpr-float64-variableref-are-not-callable/58495 "2021-04-05T12:40:13Z")

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I would like to create a Taylor expansion of an objective function but I am having trouble as the objective function is a Generic affline expression. Is there a way to use the convert () to convert the form? This is the…

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## [Combining ContinuousCallback and DiscreteCallback in solving ODEProblem (DifferentialEquations)](https://discourse.julialang.org/t/combining-continuouscallback-and-discretecallback-in-solving-odeproblem-differentialequations/58608)

<div class="topic-metadata">

**Author:** [@zdenek\_hurak](https://discourse.julialang.org/u/zdenek_hurak)\
**Replies:** 1\
**Last updated:** [April 5, 2021, 12:15pm UTC](https://discourse.julialang.org/t/combining-continuouscallback-and-discretecallback-in-solving-odeproblem-differentialequations/58608 "2021-04-05T12:15:56Z")

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Is it possible to combine ContinuousCallback and DiscreteCallback while solving ODEProblem? While the former checks if some real quantity attains a zero value, checking a simultaneous satisfaction of some additional logi…

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## [What is the "interface" necessary for DifferentialEquations.jl if your data type does not subclass AbstractArray?](https://discourse.julialang.org/t/what-is-the-interface-necessary-for-differentialequations-jl-if-your-data-type-does-not-subclass-abstractarray/58480)

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**Author:** [@Krastanov](https://discourse.julialang.org/u/Krastanov)\
**Replies:** 5\
**Last updated:** [April 5, 2021, 10:26am UTC](https://discourse.julialang.org/t/what-is-the-interface-necessary-for-differentialequations-jl-if-your-data-type-does-not-subclass-abstractarray/58480 "2021-04-05T10:26:38Z")

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There are a few similar conversation from previous years in this forum (e.g. JuliaDiffEq with custom types - #24 by mzilhao), but I was not able to find official documentation on the topic, and I am uncertain how much of…

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## [Abstract Cell Complex points, edges, faces, etc. for grids](https://discourse.julialang.org/t/abstract-cell-complex-points-edges-faces-etc-for-grids/58460)

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**Author:** [@goretkin](https://discourse.julialang.org/u/goretkin)\
**Replies:** 2\
**Last updated:** [April 5, 2021, 1:08am UTC](https://discourse.julialang.org/t/abstract-cell-complex-points-edges-faces-etc-for-grids/58460 "2021-04-05T01:08:33Z")

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Are there any packages that define a representation for n-dimensional grids as 0-cells, 1-cells, … , n-cells, with incidence relations among them? I came across \[1710.07819\] Geometric Computing with Chain Complexes: Des…

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## [LIKWID profiler](https://discourse.julialang.org/t/likwid-profiler/58543)

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**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 1\
**Last updated:** [April 4, 2021, 8:15pm UTC](https://discourse.julialang.org/t/likwid-profiler/58543 "2021-04-04T20:15:29Z")

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Definitely worth reading if you are interested in finding detail on the CPU or GPU system you are working with. If this belongs in Off Topic I will happily move it.

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## [Slider or drop menus in Makie](https://discourse.julialang.org/t/slider-or-drop-menus-in-makie/58560)

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**Author:** [@lazarusA](https://discourse.julialang.org/u/lazarusA)\
**Replies:** 6\
**Last updated:** [April 4, 2021, 8:03pm UTC](https://discourse.julialang.org/t/slider-or-drop-menus-in-makie/58560 "2021-04-04T20:03:03Z")

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Hello, probably the following is too much to ask, but could someone please take a look at this and see if it is possible to add two drop menus for l and m, or two sliders, either will be fine. I tried to follow the docu…

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## [SymPy function with 2 variables](https://discourse.julialang.org/t/sympy-function-with-2-variables/58538)

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**Author:** [@statspy](https://discourse.julialang.org/u/statspy)\
**Replies:** 4\
**Last updated:** [April 4, 2021, 7:02pm UTC](https://discourse.julialang.org/t/sympy-function-with-2-variables/58538 "2021-04-04T19:02:22Z")

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i am trying: julia\> a=Equality(x^2 + y^3, 31) i would like to get x=2 and y=3. How ca i do it? I tried solve(a,\[x,y\]) and solve(a) but i am getting: (-sqrt(31 - y^3), y) (sqrt(31 - y^3), y)

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## [Simplex transforms in Bijectors.jl (sorry)](https://discourse.julialang.org/t/simplex-transforms-in-bijectors-jl-sorry/56372)

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**Author:** [@cscherrer](https://discourse.julialang.org/u/cscherrer)\
**Replies:** 9\
**Last updated:** [April 4, 2021, 6:57pm UTC](https://discourse.julialang.org/t/simplex-transforms-in-bijectors-jl-sorry/56372 "2021-04-04T18:57:17Z")

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I’d like to understand the ideas behind the way Bijectors handles simplices. First, something I think I understand, for comparison: TransformVariables julia\> using TransformVariables julia\> t = UnitSimplex(4) UnitSimp…

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## [Best way to deregister cam2d selection zoom? GLMakie - solved](https://discourse.julialang.org/t/best-way-to-deregister-cam2d-selection-zoom-glmakie-solved/58549)

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**Author:** [@kool7d](https://discourse.julialang.org/u/kool7d)\
**Replies:** 0\
**Last updated:** [April 4, 2021, 7:06am UTC](https://discourse.julialang.org/t/best-way-to-deregister-cam2d-selection-zoom-glmakie-solved/58549 "2021-04-04T07:06:01Z")

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how do I deregister the rectangle selection zoom for cam2d? xzoomlock and yzoomlock don’t work. I can stop it from zooming if I do off(fm1.scene.events.mousedrag.listeners\[1\].mouseevent, fm1.scene.events.mousedrag.l…

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## [How to leverage conjugate priors](https://discourse.julialang.org/t/how-to-leverage-conjugate-priors/56636)

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**Author:** [@EvoArt](https://discourse.julialang.org/u/EvoArt)\
**Replies:** 2\
**Last updated:** [April 3, 2021, 9:51pm UTC](https://discourse.julialang.org/t/how-to-leverage-conjugate-priors/56636 "2021-04-03T21:51:46Z")

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I have a Turing model that I’m using to estimate how evenly distributed some count variables of interest are. I’m using the concentration parameter of a symmetric Dirichlet distribution as a measure of evenness. A simpli…

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## [Any optimization packages which implement diagonal Hessian updates?](https://discourse.julialang.org/t/any-optimization-packages-which-implement-diagonal-hessian-updates/58528)

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**Author:** [@marius311](https://discourse.julialang.org/u/marius311)\
**Replies:** 0\
**Last updated:** [April 3, 2021, 9:50pm UTC](https://discourse.julialang.org/t/any-optimization-packages-which-implement-diagonal-hessian-updates/58528 "2021-04-03T21:50:44Z")

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Are there any Julia packages which do high-dimensional unconstrained optimization and support diagonal-only updates to the Hessian? Those that I know (Optim and OptimKit) have BFGS which updates the entire Hessian, but h…

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## [Makie: Unable to produce any plot. MethodError: no method matching shadertype](https://discourse.julialang.org/t/makie-unable-to-produce-any-plot-methoderror-no-method-matching-shadertype/58519)

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**Author:** [@AAlshammaa](https://discourse.julialang.org/u/AAlshammaa)\
**Replies:** 2\
**Last updated:** [April 3, 2021, 9:04pm UTC](https://discourse.julialang.org/t/makie-unable-to-produce-any-plot-methoderror-no-method-matching-shadertype/58519 "2021-04-03T21:04:56Z")

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I am using Julia 1.6.0. I did a clean install by deleting ~/.julia then re-installed Makie package. When I try to start a scene using Scene(), or plot straight away using something like lines(1:10, 1:10) i get this erro…

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## [Taking gradients of large differential equations](https://discourse.julialang.org/t/taking-gradients-of-large-differential-equations/57788)

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**Author:** [@Dhruva2](https://discourse.julialang.org/u/Dhruva2)\
**Replies:** 4\
**Last updated:** [April 3, 2021, 4:39pm UTC](https://discourse.julialang.org/t/taking-gradients-of-large-differential-equations/57788 "2021-04-03T16:39:49Z")

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Hi all, I have a rather large reaction network I want to fit to data. I imported it from an .xml file so it is in the form of ModelingToolkit.ODESystem. It has 228 states and 470 parameters. It’s not particularly sti…

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## [Plotting difference from mean](https://discourse.julialang.org/t/plotting-difference-from-mean/58496)

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**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 8\
**Last updated:** [April 3, 2021, 4:27pm UTC](https://discourse.julialang.org/t/plotting-difference-from-mean/58496 "2021-04-03T16:27:06Z")

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If I have a CSV file with name and value pairs such as node01, 127097.3 node02, 127263.5 node03, 127132.3 … How would I make a plot of each values difference from the mean of the whole column? These are stream tria…

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## [Estimate correlation between two time series](https://discourse.julialang.org/t/estimate-correlation-between-two-time-series/58505)

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**Author:** [@stebett](https://discourse.julialang.org/u/stebett)\
**Replies:** 0\
**Last updated:** [April 3, 2021, 2:29pm UTC](https://discourse.julialang.org/t/estimate-correlation-between-two-time-series/58505 "2021-04-03T14:29:31Z")

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Hello, I’m a new Turing user and I’m not very familiar with probabilistic modeling, but the package is so cool that I couldn’t help trying to implement some of it :slight\_smile: Basically I have 2 Bernoulli/Poisson proc…

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## [Flux train all parameters except those equal to 0](https://discourse.julialang.org/t/flux-train-all-parameters-except-those-equal-to-0/55665)

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**Author:** [@anon74562486](https://discourse.julialang.org/u/anon74562486)\
**Replies:** 1\
**Last updated:** [April 2, 2021, 7:43pm UTC](https://discourse.julialang.org/t/flux-train-all-parameters-except-those-equal-to-0/55665 "2021-04-02T19:43:53Z")

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I have a neural network model trained on the mnist dataset. If I add to the loss function a l1 regularization term I get many parameters near 0. But if I set manually those parameters to 0 the model performs worse and …

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## [How are called "transversal" layers in NN?](https://discourse.julialang.org/t/how-are-called-transversal-layers-in-nn/58305)

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**Author:** [@sylvaticus](https://discourse.julialang.org/u/sylvaticus)\
**Replies:** 5\
**Last updated:** [April 2, 2021, 4:53pm UTC](https://discourse.julialang.org/t/how-are-called-transversal-layers-in-nn/58305 "2021-04-02T16:53:29Z")

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Hello, how is it known the concept in a neural network of a “transversal” or “cross section” layer ? I can’t find anything relevant with these two words… Its characteristic is that its activation function takes as input…

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## [How to make the legend fontsize larger in Makie.jl?](https://discourse.julialang.org/t/how-to-make-the-legend-fontsize-larger-in-makie-jl/58451)

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**Author:** [@ericphanson](https://discourse.julialang.org/u/ericphanson)\
**Replies:** 1\
**Last updated:** [April 2, 2021, 3:51pm UTC](https://discourse.julialang.org/t/how-to-make-the-legend-fontsize-larger-in-makie-jl/58451 "2021-04-02T15:51:25Z")

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Example: julia\> fig = Figure() Scene (512px, 320px): 0 Plots 0 Child Scenes julia\> ax = Axis(fig\[1,1\]) Axis with 0 plots: julia\> lines!(ax, sort(rand(10)), rand(10), label="Plot") Lines{Tuple{Vector{Point{2, Floa…

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