# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=398

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**Page:** 399

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## [RNN Not learning](https://discourse.julialang.org/t/rnn-not-learning/51686)

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**Author:** [@Emilio4d46](https://discourse.julialang.org/u/Emilio4d46)\
**Replies:** 9\
**Last updated:** [January 4, 2021, 9:46am UTC](https://discourse.julialang.org/t/rnn-not-learning/51686 "2021-01-04T09:46:32Z")

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I have been trying to build an RNN in Julia using Flux and it does not seem to converge or learn at all. The code is learning on a parsed Stanford Sentiment Treebank (i.e. An array of words and a sentiment score) Th…

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## [@NLconstraint with a sum, array and scalar variables](https://discourse.julialang.org/t/nlconstraint-with-a-sum-array-and-scalar-variables/52710)

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**Author:** [@maajdl](https://discourse.julialang.org/u/maajdl)\
**Replies:** 5\
**Last updated:** [January 4, 2021, 8:47am UTC](https://discourse.julialang.org/t/nlconstraint-with-a-sum-array-and-scalar-variables/52710 "2021-01-04T08:47:18Z")

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Hello and happy new year! Below is a toy problem. It deals with a mix of 4 chemicals. The quantities of the chemicals are given in the array xs. The temperature of the mix is the only unknow, subject to the constrai…

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## [Meaning of Δ in different \`apply!\` methods is different in different Flux optimizers?](https://discourse.julialang.org/t/meaning-of-in-different-apply-methods-is-different-in-different-flux-optimizers/52811)

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**Author:** [@gxyd](https://discourse.julialang.org/u/gxyd)\
**Replies:** 0\
**Last updated:** [January 4, 2021, 7:57am UTC](https://discourse.julialang.org/t/meaning-of-in-different-apply-methods-is-different-in-different-flux-optimizers/52811 "2021-01-04T07:57:08Z")

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Hi, I want to understand the meaning of Δ used in different methods (i.e. for different optimizers) in Flux. For example: in Descent, the meaning of Δ seems to be: \[∂f/∂θᵢ\] i=1,2,3,… While looking at the meaning of Δ …

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## [Map Performance with CuArrays](https://discourse.julialang.org/t/map-performance-with-cuarrays/33497)

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**Author:** [@bmit](https://discourse.julialang.org/u/bmit)\
**Replies:** 15\
**Last updated:** [January 4, 2021, 7:29am UTC](https://discourse.julialang.org/t/map-performance-with-cuarrays/33497 "2021-01-04T07:29:48Z")

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I’m trying to benchmark different methods of calling the same in-place function on subsets of a large data block using CuArrays. I’m using fft as an example function because I can baseline against planning an fft over on…

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## [Sum is very slow (and I can't figure out why)](https://discourse.julialang.org/t/sum-is-very-slow-and-i-cant-figure-out-why/52791)

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**Author:** [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)\
**Replies:** 4\
**Last updated:** [January 4, 2021, 7:25am UTC](https://discourse.julialang.org/t/sum-is-very-slow-and-i-cant-figure-out-why/52791 "2021-01-04T07:25:42Z")

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Hi, I’m building up a Monte Carlo code in CUDA that, as intermediate steps, needs to perform sums of several thousand Floats. The fact is that the numbers are produced by a function V(r,dip) where r is vector of floats …

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## [CUDA does not successfully initialise](https://discourse.julialang.org/t/cuda-does-not-successfully-initialise/52661)

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**Author:** [@iHany](https://discourse.julialang.org/u/iHany)\
**Replies:** 2\
**Last updated:** [January 4, 2021, 7:20am UTC](https://discourse.julialang.org/t/cuda-does-not-successfully-initialise/52661 "2021-01-04T07:20:24Z")

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I installed CUDA by \]add CUDA and tried to test it by test CUDA. However, I encountered the below error message. CUDA initialisation error ERROR: LoadError: CUDA.jl did not successfully initialize, and is not usable. I…

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## [WGLMakie meshscatter plot GPU load goes to 70% and stays there](https://discourse.julialang.org/t/wglmakie-meshscatter-plot-gpu-load-goes-to-70-and-stays-there/52810)

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**Author:** [@woolstar](https://discourse.julialang.org/u/woolstar)\
**Replies:** 0\
**Last updated:** [January 4, 2021, 5:52am UTC](https://discourse.julialang.org/t/wglmakie-meshscatter-plot-gpu-load-goes-to-70-and-stays-there/52810 "2021-01-04T05:52:05Z")

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I am doing some 3D plotting in Makie (using WGLMakie in Pluto), and even when not changing the scene, the load on my graphics card goes to about 70% and stays there, as if it is continually redrawing the scene. Is there…

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## [Sending functions within structs to workers leads to world age problem](https://discourse.julialang.org/t/sending-functions-within-structs-to-workers-leads-to-world-age-problem/52717)

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**Author:** [@vancleve](https://discourse.julialang.org/u/vancleve)\
**Replies:** 4\
**Last updated:** [January 4, 2021, 3:34am UTC](https://discourse.julialang.org/t/sending-functions-within-structs-to-workers-leads-to-world-age-problem/52717 "2021-01-04T03:34:25Z")

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I have a simulation where I pass functions as parameters by putting them in a parameter object. However, when I try to run the simulation using Distributed, the functions do not run in the workers due to their world age …

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## [Create a simple CUDA.sum kernel](https://discourse.julialang.org/t/create-a-simple-cuda-sum-kernel/52797)

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**Author:** [@Ferran\_Mazzanti](https://discourse.julialang.org/u/Ferran_Mazzanti)\
**Replies:** 3\
**Last updated:** [January 3, 2021, 10:09pm UTC](https://discourse.julialang.org/t/create-a-simple-cuda-sum-kernel/52797 "2021-01-03T22:09:23Z")

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Hi again, as you can see, I’m trying to understand some basic CUDA kernel programming under julia, so please try not to be too rough with me… :slight\_smile: This time I want to build up a kernel that takes a bunch of …

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## [Working implementation of MAML (meta-learning) for FluxML?](https://discourse.julialang.org/t/working-implementation-of-maml-meta-learning-for-fluxml/51954)

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**Author:** [@bad\_at\_math](https://discourse.julialang.org/u/bad_at_math)\
**Replies:** 1\
**Last updated:** [January 3, 2021, 5:37pm UTC](https://discourse.julialang.org/t/working-implementation-of-maml-meta-learning-for-fluxml/51954 "2021-01-03T17:37:24Z")

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Hi everyone, I was wondering if there are any public implementations of meta-learning techniques such as MAML (\[1703.03400\] Model-Agnostic Meta-Learning for Fast Adaptation of Deep Networks) in Flux. The model zoo has a…

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## [Showing plots within DataFrames.jl + Plots.jl](https://discourse.julialang.org/t/showing-plots-within-dataframes-jl-plots-jl/52708)

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**Author:** [@delnatan](https://discourse.julialang.org/u/delnatan)\
**Replies:** 4\
**Last updated:** [January 2, 2021, 6:17pm UTC](https://discourse.julialang.org/t/showing-plots-within-dataframes-jl-plots-jl/52708 "2021-01-02T18:17:43Z")

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Hi everyone! I was playing around with Pluto.jl and found that you can display individual plots stored in a column within a DataFrame. This is pretty cool! For example: using Plots using DataFrames arrplots = \[ plot…

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## [BoundsError on basic Turing model](https://discourse.julialang.org/t/boundserror-on-basic-turing-model/52701)

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**Author:** [@rikh](https://discourse.julialang.org/u/rikh)\
**Replies:** 2\
**Last updated:** [January 2, 2021, 9:07am UTC](https://discourse.julialang.org/t/boundserror-on-basic-turing-model/52701 "2021-01-02T09:07:53Z")

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I’m trying to fit a basic model in Turing. The data consists of some values y (lets say a height) for different groups/categories x. I am trying to learn whether the y-values per group differ, or are the same. To make it…

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## [Can ContinuousCallbacks in DifferentialEquations.jl be used to watch parameters?](https://discourse.julialang.org/t/can-continuouscallbacks-in-differentialequations-jl-be-used-to-watch-parameters/52674)

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**Author:** [@klaff](https://discourse.julialang.org/u/klaff)\
**Replies:** 10\
**Last updated:** [January 2, 2021, 5:49am UTC](https://discourse.julialang.org/t/can-continuouscallbacks-in-differentialequations-jl-be-used-to-watch-parameters/52674 "2021-01-02T05:49:34Z")

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I’m trying to use a VectorContinuousCallback to handle friction and end stops. Some of the conditions are not based on the state variables u but on a value stuffed into a field of the parameters p. Code: using Differen…

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## [How can i use sets created using LasySets.jl with Convex.jl variables?](https://discourse.julialang.org/t/how-can-i-use-sets-created-using-lasysets-jl-with-convex-jl-variables/52572)

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**Author:** [@adropintheriver](https://discourse.julialang.org/u/adropintheriver)\
**Replies:** 6\
**Last updated:** [January 2, 2021, 1:49am UTC](https://discourse.julialang.org/t/how-can-i-use-sets-created-using-lasysets-jl-with-convex-jl-variables/52572 "2021-01-02T01:49:27Z")

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Is there a way i can create LazySets Polyhedron and use it as a variable in my optimization program that uses Convex.jl, use them in constraints i want to add to the problem?.

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## [JuMP - variable depending on other variable](https://discourse.julialang.org/t/jump-variable-depending-on-other-variable/52529)

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**Author:** [@TheMEGuy](https://discourse.julialang.org/u/TheMEGuy)\
**Replies:** 2\
**Last updated:** [January 1, 2021, 11:15pm UTC](https://discourse.julialang.org/t/jump-variable-depending-on-other-variable/52529 "2021-01-01T23:15:03Z")

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Hi, I have a variable that is supposed to be a matrix. Its size should depend on another variable, which also should be optimized, or at least changed throughout the optimization process: @variable(model, n,lower\_bound…

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## [Plots.jl: can we connect two points in a D-2 plot with a straight line?](https://discourse.julialang.org/t/plots-jl-can-we-connect-two-points-in-a-d-2-plot-with-a-straight-line/52711)

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**Author:** [@VivMendes](https://discourse.julialang.org/u/VivMendes)\
**Replies:** 2\
**Last updated:** [January 1, 2021, 10:41pm UTC](https://discourse.julialang.org/t/plots-jl-can-we-connect-two-points-in-a-d-2-plot-with-a-straight-line/52711 "2021-01-01T22:41:57Z")

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Suppose I have a D-2 plot produced by Plots.jl, which may display a time series or a mere parabola. Is it possible to connect two points with a straight line by using annotations or any other Plots’ functionality? I am n…

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## [Is there a way to compute the AD Hessian of a function using purely Zygote functions and not ForwardDiff?](https://discourse.julialang.org/t/is-there-a-way-to-compute-the-ad-hessian-of-a-function-using-purely-zygote-functions-and-not-forwarddiff/52704)

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**Author:** [@tholdem](https://discourse.julialang.org/u/tholdem)\
**Replies:** 1\
**Last updated:** [January 1, 2021, 7:01pm UTC](https://discourse.julialang.org/t/is-there-a-way-to-compute-the-ad-hessian-of-a-function-using-purely-zygote-functions-and-not-forwarddiff/52704 "2021-01-01T19:01:19Z")

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To solve the issue raised in this post, I’ve been trying to write a Jacobian function using Zygote functions only so I can compute the AD Hessian of my function without using Dual type from ForwardDiff, which doesn’t wor…

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## [How can I extract MOI expression from a linear JuMP obj expression](https://discourse.julialang.org/t/how-can-i-extract-moi-expression-from-a-linear-jump-obj-expression/52689)

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**Author:** [@Mahbubar06](https://discourse.julialang.org/u/Mahbubar06)\
**Replies:** 2\
**Last updated:** [January 1, 2021, 2:34pm UTC](https://discourse.julialang.org/t/how-can-i-extract-moi-expression-from-a-linear-jump-obj-expression/52689 "2021-01-01T14:34:51Z")

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Hello, I am struggling to generate an MOI (MathOptInterface) expression from a linear JuMP expression. I have a JuMP model as follows. m = Model(Ipopt.Optimizer) @variable(m, 0 \<= x\[1:3\] \<= 10) @constraint(m, sum(x\[i\]…

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## [Convex.jl - LoadError: UndefVarError: AbstractExpr not defined](https://discourse.julialang.org/t/convex-jl-loaderror-undefvarerror-abstractexpr-not-defined/52679)

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**Author:** [@cm0](https://discourse.julialang.org/u/cm0)\
**Replies:** 3\
**Last updated:** [January 1, 2021, 11:04am UTC](https://discourse.julialang.org/t/convex-jl-loaderror-undefvarerror-abstractexpr-not-defined/52679 "2021-01-01T11:04:56Z")

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I am using Julia 1.5.3 but running some old code based on Julia 0.6.4 and ran into the following problem: LoadError: LoadError: UndefVarError: AbstractExpr not defined. The problem seems to be AbstractExpr no longer bei…

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## [Simple Turing model fails for InexactError](https://discourse.julialang.org/t/simple-turing-model-fails-for-inexacterror/52655)

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**Author:** [@BradGroff](https://discourse.julialang.org/u/BradGroff)\
**Replies:** 5\
**Last updated:** [December 31, 2020, 7:04pm UTC](https://discourse.julialang.org/t/simple-turing-model-fails-for-inexacterror/52655 "2020-12-31T19:04:55Z")

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Hi all, The model is a simple binomial on binary data: @model function coinflip\_binomial\_broken(y::Array{Int64}) # prior on p p ~ Beta(1, 1) # updates on p heads = sum(y) heads ~ Binomial(lengt…

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## [Packages used to create animated reaction systems](https://discourse.julialang.org/t/packages-used-to-create-animated-reaction-systems/52664)

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**Author:** [@22natarajank](https://discourse.julialang.org/u/22natarajank)\
**Replies:** 2\
**Last updated:** [December 31, 2020, 4:35pm UTC](https://discourse.julialang.org/t/packages-used-to-create-animated-reaction-systems/52664 "2020-12-31T16:35:53Z")

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Hello! I am working on a Pluto notebook where I am trying to simulate how reaction systems will naturally move back to equilibrium, even after making changes to concentrations of the species, the addition of catalysts, o…

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## [LibPQ.Errors.PQResultError](https://discourse.julialang.org/t/libpq-errors-pqresulterror/52649)

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**Author:** [@Laco\_Kovac](https://discourse.julialang.org/u/Laco_Kovac)\
**Replies:** 0\
**Last updated:** [December 31, 2020, 9:27am UTC](https://discourse.julialang.org/t/libpq-errors-pqresulterror/52649 "2020-12-31T09:27:53Z")

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I am quite new to Julia and I suspect my question is probably rather about how to access/analyze data type/structure. Using LibPQ, execute is throwing an exception exc. typeof(exc) is LibPQ.Errors.PQResultError{LibPQ.E…

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## [Static website](https://discourse.julialang.org/t/static-website/52492)

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**Author:** [@Kampuny11](https://discourse.julialang.org/u/Kampuny11)\
**Replies:** 2\
**Last updated:** [December 30, 2020, 10:32pm UTC](https://discourse.julialang.org/t/static-website/52492 "2020-12-30T22:32:03Z")

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Does anyone know any documentation about Franklin for website creation? or is there another tool with documentation?

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## [Are there good resources for learning deep learning in Julia?](https://discourse.julialang.org/t/are-there-good-resources-for-learning-deep-learning-in-julia/48355)

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**Author:** [@greatpet](https://discourse.julialang.org/u/greatpet)\
**Replies:** 3\
**Last updated:** [December 30, 2020, 5:08pm UTC](https://discourse.julialang.org/t/are-there-good-resources-for-learning-deep-learning-in-julia/48355 "2020-12-30T17:08:17Z")

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I want to learn some machine learning / deep learning in my spare time, to understand algorithms like Google’s AlphaGo. I recently learned Julia and I’m wondering if there are good pedagogical introductions to ML without…

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## [So I think I've learned the basics of Julia, where do I learn some more advanced content? (specifcally image feature extraction)](https://discourse.julialang.org/t/so-i-think-ive-learned-the-basics-of-julia-where-do-i-learn-some-more-advanced-content-specifcally-image-feature-extraction/34108)

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**Author:** [@samantp](https://discourse.julialang.org/u/samantp)\
**Replies:** 3\
**Last updated:** [December 30, 2020, 2:01pm UTC](https://discourse.julialang.org/t/so-i-think-ive-learned-the-basics-of-julia-where-do-i-learn-some-more-advanced-content-specifcally-image-feature-extraction/34108 "2020-12-30T14:01:00Z")

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I am learning to use Julia for my new research (MRI image feature extraction and classification). The language I am most comfortable with is MATLAB but I also have some basic understanding of python. What I don’t yet hav…

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## [Compute integral of a beta distribution](https://discourse.julialang.org/t/compute-integral-of-a-beta-distribution/52607)

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**Author:** [@TBu](https://discourse.julialang.org/u/TBu)\
**Replies:** 7\
**Last updated:** [December 30, 2020, 12:40pm UTC](https://discourse.julialang.org/t/compute-integral-of-a-beta-distribution/52607 "2020-12-30T12:40:54Z")

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Hi everyone, I used the Distributions package in order to generate a beta distribution, which works quite nicely: using Distributions d = Beta(10,15) However - is it possible to integrate over an interval of the distr…

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## [ANN MinimallyDisruptiveCurves.jl](https://discourse.julialang.org/t/ann-minimallydisruptivecurves-jl/47874)

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**Author:** [@Dhruva2](https://discourse.julialang.org/u/Dhruva2)\
**Replies:** 5\
**Last updated:** [December 30, 2020, 10:46am UTC](https://discourse.julialang.org/t/ann-minimallydisruptivecurves-jl/47874 "2020-12-30T10:46:07Z")

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Hi all, I thought I would crosspost my package announcement here. The package implements a recent algorithm for regional sensitivity analysis of models with many parameters. Any models, as long as there is a differe…

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## [How to reindex in DataFrames?](https://discourse.julialang.org/t/how-to-reindex-in-dataframes/51112)

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**Author:** [@timueh](https://discourse.julialang.org/u/timueh)\
**Replies:** 9\
**Last updated:** [December 30, 2020, 7:29am UTC](https://discourse.julialang.org/t/how-to-reindex-in-dataframes/51112 "2020-12-30T07:29:36Z")

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I am looking for a reindex function for DataFrames that allows to reindex a column with respect to a new column. Suppose I build a data frame like this julia\> ind = today():Day(2):today()+Day(10) Date("2020-12-02"):Day…

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## [Beginning to compare LTSpice and Julia Diff Eq](https://discourse.julialang.org/t/beginning-to-compare-ltspice-and-julia-diff-eq/51988)

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**Author:** [@klaff](https://discourse.julialang.org/u/klaff)\
**Replies:** 8\
**Last updated:** [December 30, 2020, 12:08am UTC](https://discourse.julialang.org/t/beginning-to-compare-ltspice-and-julia-diff-eq/51988 "2020-12-30T00:08:33Z")

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I’ve been doing mixed simulations (some electronics, some physics, some digital control) for a bit and wrote up a little Pluto notebook comparing a tank circuit simulation in LTSpice and using DiffEq. I was surprised at …

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## [How to set face color per triangle when using plot\_trisurf in PyPlot](https://discourse.julialang.org/t/how-to-set-face-color-per-triangle-when-using-plot-trisurf-in-pyplot/4662)

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**Author:** [@fruno](https://discourse.julialang.org/u/fruno)\
**Replies:** 9\
**Last updated:** [December 29, 2020, 9:56pm UTC](https://discourse.julialang.org/t/how-to-set-face-color-per-triangle-when-using-plot-trisurf-in-pyplot/4662 "2020-12-29T21:56:31Z")

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Hi, I want to set the face color of each triangle individually when plotting with plot\_trisurf in PyPlot. The matplotlib manual seems to indicate that face color is set with the option ‘color’ (as a tuple), but there is …

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