# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?no_subcategories=false&page=178

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**Page:** 179

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## [Handling an overflow example in QuadGK](https://discourse.julialang.org/t/handling-an-overflow-example-in-quadgk/101657)

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**Author:** [@stevengj](https://discourse.julialang.org/u/stevengj)\
**Replies:** 5\
**Last updated:** [July 16, 2023, 2:06pm UTC](https://discourse.julialang.org/t/handling-an-overflow-example-in-quadgk/101657 "2023-07-16T14:06:11Z")

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Someone asked me this question over email, and I decided to post my answer here since it might be of more general interest. Suppose that we are trying to compute \\int\_0^\\infty (e^y - 1) \\frac{e^{-2.5y}}{y^{1.2}} dy. Th…

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## [How to generate white noise?](https://discourse.julialang.org/t/how-to-generate-white-noise/101673)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 1\
**Last updated:** [July 16, 2023, 12:38pm UTC](https://discourse.julialang.org/t/how-to-generate-white-noise/101673 "2023-07-16T12:38:24Z")

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I need some white noise, which I then can shape to have the required spectrum using filters. But how to I generate white noise? I could do it using rand or randn: noise1=rand(Int(1e6)).-0.5 noise2=randn(Int(1e6)) I ge…

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## [FFTW plan applied to array with wrong memory alignment](https://discourse.julialang.org/t/fftw-plan-applied-to-array-with-wrong-memory-alignment/101672)

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**Author:** [@ymtoo](https://discourse.julialang.org/u/ymtoo)\
**Replies:** 0\
**Last updated:** [July 16, 2023, 9:43am UTC](https://discourse.julialang.org/t/fftw-plan-applied-to-array-with-wrong-memory-alignment/101672 "2023-07-16T09:43:30Z")

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MWE: using ChainRulesCore: @ignore\_derivatives using DSP using DSP.Periodograms: forward\_plan using Zygote function mystft(x::AbstractVector{T}, n, noverlap) where {T} numsamples = length(x) numframes = numsamp…

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## [How can I use a linear model with NaN parameters due to missing train data?](https://discourse.julialang.org/t/how-can-i-use-a-linear-model-with-nan-parameters-due-to-missing-train-data/101648)

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**Author:** [@bertulli](https://discourse.julialang.org/u/bertulli)\
**Replies:** 0\
**Last updated:** [July 15, 2023, 10:09am UTC](https://discourse.julialang.org/t/how-can-i-use-a-linear-model-with-nan-parameters-due-to-missing-train-data/101648 "2023-07-15T10:09:28Z")

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Hi all! I am trying to build a model to predict electrical powers from a sequence of binary computer instructions. I thought to use a multiple linear regression, as from each instruction there are a lot of variables I c…

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## [Makie/FFMPEG pb libharfbuzz.so.0: undefined symbol: FT\_Get\_Transform](https://discourse.julialang.org/t/makie-ffmpeg-pb-libharfbuzz-so-0-undefined-symbol-ft-get-transform/99570)

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**Author:** [@LaurentPlagne](https://discourse.julialang.org/u/LaurentPlagne)\
**Replies:** 12\
**Last updated:** [July 15, 2023, 9:38am UTC](https://discourse.julialang.org/t/makie-ffmpeg-pb-libharfbuzz-so-0-undefined-symbol-ft-get-transform/99570 "2023-07-15T09:38:24Z")

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Hi, I have a bug during animation with CairoMakie. I try the example from the doc: using CairoMakie scene = lines(rand(10); linewidth=10) record(scene, "out.mp4", 1:255; framerate = 60) do i scene.plots\[2\]\[:color…

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## [OrdinaryDiffEq.jl Buffer for Past Values Through Previous Iterations](https://discourse.julialang.org/t/ordinarydiffeq-jl-buffer-for-past-values-through-previous-iterations/101641)

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**Author:** [@mwu](https://discourse.julialang.org/u/mwu)\
**Replies:** 1\
**Last updated:** [July 15, 2023, 2:33am UTC](https://discourse.julialang.org/t/ordinarydiffeq-jl-buffer-for-past-values-through-previous-iterations/101641 "2023-07-15T02:33:39Z")

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I have an ODE system from OrdinaryDiffEq.jl. I want to model a digital filter that needs to know the past 7 values of a particular variable. Essentially, I want a buffer of sorts to keep track of the value of this variab…

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## [GCMMA using NLopt](https://discourse.julialang.org/t/gcmma-using-nlopt/101642)

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**Author:** [@mary](https://discourse.julialang.org/u/mary)\
**Replies:** 5\
**Last updated:** [July 15, 2023, 1:23am UTC](https://discourse.julialang.org/t/gcmma-using-nlopt/101642 "2023-07-15T01:23:20Z")

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Hi All. I have a question can i use NLopt for GCMMA algorithm? also one other question can zygote has errors in calculating gradients? thank you

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## [Comparing Plot Outputs for Different Versions of Julia](https://discourse.julialang.org/t/comparing-plot-outputs-for-different-versions-of-julia/101538)

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**Author:** [@emmabottomley](https://discourse.julialang.org/u/emmabottomley)\
**Replies:** 3\
**Last updated:** [July 15, 2023, 12:18am UTC](https://discourse.julialang.org/t/comparing-plot-outputs-for-different-versions-of-julia/101538 "2023-07-15T00:18:05Z")

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Hello! I’m working on solving PDEs in julia and producing plots of their solutions for different lengths of time. I was having a lot of issues when using Julia v-1.9.0. When I increased the time in this specific settin…

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## [Basis functions to approximate the inverse of quadratic function](https://discourse.julialang.org/t/basis-functions-to-approximate-the-inverse-of-quadratic-function/101449)

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**Author:** [@EricJohnson](https://discourse.julialang.org/u/EricJohnson)\
**Replies:** 33\
**Last updated:** [July 14, 2023, 10:58pm UTC](https://discourse.julialang.org/t/basis-functions-to-approximate-the-inverse-of-quadratic-function/101449 "2023-07-14T22:58:55Z")

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I have many observations of measuring a physical parameter over time. Each observation is basically a function p(t), t \\in \[t\_1, t\_2\]. I also have the value \\int\_{t\_1}^{t\_2} q (t) dt = Q I have many observations: \\le…

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## [Implementing Particle Life in Julia? | Graphics Simulator? | Physics Simulator (with visualisation)?](https://discourse.julialang.org/t/implementing-particle-life-in-julia-graphics-simulator-physics-simulator-with-visualisation/101563)

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**Author:** [@Maddy](https://discourse.julialang.org/u/Maddy)\
**Replies:** 4\
**Last updated:** [July 14, 2023, 9:44pm UTC](https://discourse.julialang.org/t/implementing-particle-life-in-julia-graphics-simulator-physics-simulator-with-visualisation/101563 "2023-07-14T21:44:04Z")

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Tom Mohr has shown his implementation of Particle Life here I was wondering if we can do that in Julia since a longgg time! But I just can’t find a graphics library that has real-time rendering (along with some interac…

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## [KeyError: key 'C' not found when using modelingtoolkitize command](https://discourse.julialang.org/t/keyerror-key-c-not-found-when-using-modelingtoolkitize-command/101553)

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**Author:** [@Nick1](https://discourse.julialang.org/u/Nick1)\
**Replies:** 3\
**Last updated:** [July 14, 2023, 8:39pm UTC](https://discourse.julialang.org/t/keyerror-key-c-not-found-when-using-modelingtoolkitize-command/101553 "2023-07-14T20:39:47Z")

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I am using the modelingtoolkitize command to convert a large system of ODEs to symbolic expressions in order to perform Structural Identifiability Analysis. However, I am receiving the following error: KeyError: key ‘…

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## [GPU Parallel Computing for Global Sensitivity Analysis](https://discourse.julialang.org/t/gpu-parallel-computing-for-global-sensitivity-analysis/101545)

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**Author:** [@Nick1](https://discourse.julialang.org/u/Nick1)\
**Replies:** 2\
**Last updated:** [July 14, 2023, 8:24pm UTC](https://discourse.julialang.org/t/gpu-parallel-computing-for-global-sensitivity-analysis/101545 "2023-07-14T20:24:31Z")

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Hi everyone. I try to speed up Global Sensitivity Analysis calculations based on the code in this link (Global sensitivity analysis in a large parameter space - computational cost - #11 by TS-CUBED). Essentially, I chang…

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## [Q: Optimization.jl | Passing fixed parameters to an analytic derivative \[gradient\] for univariate \[multivariate\] optimization?](https://discourse.julialang.org/t/q-optimization-jl-passing-fixed-parameters-to-an-analytic-derivative-gradient-for-univariate-multivariate-optimization/101605)

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**Author:** [@Audrius-St](https://discourse.julialang.org/u/Audrius-St)\
**Replies:** 2\
**Last updated:** [July 14, 2023, 7:41pm UTC](https://discourse.julialang.org/t/q-optimization-jl-passing-fixed-parameters-to-an-analytic-derivative-gradient-for-univariate-multivariate-optimization/101605 "2023-07-14T19:41:12Z")

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The Optimization.jl documentation states " Defining gradients can be done in two ways. One way is to manually provide a gradient definition in the OptimizationFunction constructor. However, the more convenient way to obt…

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## [DifferentialEquations.jl VectorContinuousCallback vs CallbackSet](https://discourse.julialang.org/t/differentialequations-jl-vectorcontinuouscallback-vs-callbackset/88536)

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**Author:** [@Max\_M](https://discourse.julialang.org/u/Max_M)\
**Replies:** 7\
**Last updated:** [July 14, 2023, 6:48pm UTC](https://discourse.julialang.org/t/differentialequations-jl-vectorcontinuouscallback-vs-callbackset/88536 "2023-07-14T18:48:35Z")

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From the docs: The \[VectorContinuousCallback\] https://diffeq.sciml.ai/stable/features/callback\_functions/#SciMLBase.VectorContinuousCallback) works like a vector of ContinuousCallbacks and lets the user specify which c…

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## [Deprected - Q: Optim.jl | Passing fixed parameters to an analytic derivative \[gradient\] for univariate \[multivariate\] optimization?](https://discourse.julialang.org/t/deprected-q-optim-jl-passing-fixed-parameters-to-an-analytic-derivative-gradient-for-univariate-multivariate-optimization/101551)

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**Author:** [@Audrius-St](https://discourse.julialang.org/u/Audrius-St)\
**Replies:** 0\
**Last updated:** [July 12, 2023, 9:28pm UTC](https://discourse.julialang.org/t/deprected-q-optim-jl-passing-fixed-parameters-to-an-analytic-derivative-gradient-for-univariate-multivariate-optimization/101551 "2023-07-12T21:28:33Z")

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This question is deprecated and is replaced by Q: Optimization.jl | Passing fixed parameters to an analytic derivative \[gradient\] for univariate \[multivariate\] optimization? Hello, This question may be considered a con…

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## [How can I get the maximum of an absolute value of an objective](https://discourse.julialang.org/t/how-can-i-get-the-maximum-of-an-absolute-value-of-an-objective/101356)

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**Author:** [@That\_ind](https://discourse.julialang.org/u/That_ind)\
**Replies:** 9\
**Last updated:** [July 14, 2023, 4:30am UTC](https://discourse.julialang.org/t/how-can-i-get-the-maximum-of-an-absolute-value-of-an-objective/101356 "2023-07-14T04:30:40Z")

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Hi, How can I get the maximum of an absolute value of an objective? Something like @objective(model, Max, abs(var\_ref)) But I got the following ERROR: LoadError: MethodError: no method matching abs(::AffExpr)

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## [Is there a convenient way to read netCDF datasets stored in nested groups when using NCDatasets.jl?](https://discourse.julialang.org/t/is-there-a-convenient-way-to-read-netcdf-datasets-stored-in-nested-groups-when-using-ncdatasets-jl/101589)

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**Author:** [@haffner](https://discourse.julialang.org/u/haffner)\
**Replies:** 3\
**Last updated:** [July 14, 2023, 12:07am UTC](https://discourse.julialang.org/t/is-there-a-convenient-way-to-read-netcdf-datasets-stored-in-nested-groups-when-using-ncdatasets-jl/101589 "2023-07-14T00:07:22Z")

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Hi, I’m relatively new to Julia and trying to use NCDatasets.jl to read satellite data stored in netCDF files. The data are stored in compound groups at the end of a path like this /BAND1\_RADIANCE/STANDARD\_MODE/GEODATA…

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## [JuMP SCIP Error: no shadow price for LP](https://discourse.julialang.org/t/jump-scip-error-no-shadow-price-for-lp/101138)

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**Author:** [@Stuart\_Rogers](https://discourse.julialang.org/u/Stuart_Rogers)\
**Replies:** 2\
**Last updated:** [July 13, 2023, 10:26pm UTC](https://discourse.julialang.org/t/jump-scip-error-no-shadow-price-for-lp/101138 "2023-07-13T22:26:56Z")

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I get an error about a missing shadow price when I try to use SCIP to solve a simle LP in JuMP. I don’t get the error if I use HiGHS or COPT. I use Julia v1.9.1 and the following packages: pkg\> status Status ~/.julia/e…

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## [Optim.jl NelderMead, how to avoid stucking situation?](https://discourse.julialang.org/t/optim-jl-neldermead-how-to-avoid-stucking-situation/101590)

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**Author:** [@Zerosum](https://discourse.julialang.org/u/Zerosum)\
**Replies:** 1\
**Last updated:** [July 13, 2023, 9:34pm UTC](https://discourse.julialang.org/t/optim-jl-neldermead-how-to-avoid-stucking-situation/101590 "2023-07-13T21:34:00Z")

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I think this is a question more related to optimization than Julia’s. I figured out that Optim.jl NelderMead algorithm doesn’t support fminbox. The out-of-boundary search is not a real problem because I can impose some …

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## [Bounding variables in a NonlinearSystem using MTK](https://discourse.julialang.org/t/bounding-variables-in-a-nonlinearsystem-using-mtk/101582)

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**Author:** [@chris-hampel-CA](https://discourse.julialang.org/u/chris-hampel-CA)\
**Replies:** 3\
**Last updated:** [July 13, 2023, 9:14pm UTC](https://discourse.julialang.org/t/bounding-variables-in-a-nonlinearsystem-using-mtk/101582 "2023-07-13T21:14:02Z")

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Hello, I have a general question about using ModelingToolkit when solving a NonlinearSystem. I noticed when building an OptimizationSystem you can bound your variables. Modeling Optimization Problems · ModelingToolkit.…

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## [Error with WENO Scheme](https://discourse.julialang.org/t/error-with-weno-scheme/99005)

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**Author:** [@emmabottomley](https://discourse.julialang.org/u/emmabottomley)\
**Replies:** 3\
**Last updated:** [July 13, 2023, 8:14pm UTC](https://discourse.julialang.org/t/error-with-weno-scheme/99005 "2023-07-13T20:14:38Z")

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I’m having trouble using the WENO Scheme for my system of PDEs. My system is given as and I have the following code to solve the numerical solution for each equation: using OrdinaryDiffEq, ModelingToolkit, MethodOfL…

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## [Neural SDE example no method matching error](https://discourse.julialang.org/t/neural-sde-example-no-method-matching-error/101542)

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**Author:** [@Mieszko](https://discourse.julialang.org/u/Mieszko)\
**Replies:** 2\
**Last updated:** [July 13, 2023, 10:53am UTC](https://discourse.julialang.org/t/neural-sde-example-no-method-matching-error/101542 "2023-07-13T10:53:22Z")

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Hi, I was following this tutorial for NeuralSDEs: https://docs.juliahub.com/DiffEqFlux/BdO4p/1.10.3/examples/NN-SDE/. I tried to compile in Visual Studio and reached it until this moment: using Plots, Flux, DiffEqFlux…

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## [Stochastic differential equation with high dimensions is using too much memory and taking too long](https://discourse.julialang.org/t/stochastic-differential-equation-with-high-dimensions-is-using-too-much-memory-and-taking-too-long/101478)

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**Author:** [@KalelR](https://discourse.julialang.org/u/KalelR)\
**Replies:** 12\
**Last updated:** [July 13, 2023, 10:52am UTC](https://discourse.julialang.org/t/stochastic-differential-equation-with-high-dimensions-is-using-too-much-memory-and-taking-too-long/101478 "2023-07-13T10:52:05Z")

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Hey! I want to integrate a system of 40+ differential equations each with independent additive white noise. With the current implementation I’m trying this is using way too much memory and is too slow. A minimal example …

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## [Plots.contour rounding the contour labels](https://discourse.julialang.org/t/plots-contour-rounding-the-contour-labels/100939)

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**Author:** [@selvi-aras](https://discourse.julialang.org/u/selvi-aras)\
**Replies:** 3\
**Last updated:** [July 13, 2023, 9:28am UTC](https://discourse.julialang.org/t/plots-contour-rounding-the-contour-labels/100939 "2023-07-13T09:28:52Z")

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I am using Plots.jl to generate a contour plot. It works great but the contour labels have 5 digits after the decimal point: How can I update my code, which is shared next, so that the contour labels are rounded to de…

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## [How do I get the bounds (or center) of a named region in GMT.jl](https://discourse.julialang.org/t/how-do-i-get-the-bounds-or-center-of-a-named-region-in-gmt-jl/101506)

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**Author:** [@Philip\_Stuckey](https://discourse.julialang.org/u/Philip_Stuckey)\
**Replies:** 3\
**Last updated:** [July 13, 2023, 1:06am UTC](https://discourse.julialang.org/t/how-do-i-get-the-bounds-or-center-of-a-named-region-in-gmt-jl/101506 "2023-07-13T01:06:16Z")

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Hi, so I’m messing around with making a map of California with a Lambert Conic Projection (my eventual goal is to make maps of the maidenhead locator for various states), unfortunately it’s at an angle unless I manually …

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## [Shade in Region between two lines - Makie](https://discourse.julialang.org/t/shade-in-region-between-two-lines-makie/101529)

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**Author:** [@xztt](https://discourse.julialang.org/u/xztt)\
**Replies:** 5\
**Last updated:** [July 12, 2023, 9:29pm UTC](https://discourse.julialang.org/t/shade-in-region-between-two-lines-makie/101529 "2023-07-12T21:29:11Z")

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Hi, In Makie I can plot two linear lines with the code x = LinRange(0,100,101) f = Figure(); ax = Axis(f\[1,1\]) lines!(x, 30 .+ 0.6\*x, color = :blue, label = "Lower") lines!(x, 2 .+ 1.1\*x, color = :blue, label = "Upper"…

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## [Get MLE parameters (e.g., p-value, confidence intervals...) from a Turing model using Optim.jl](https://discourse.julialang.org/t/get-mle-parameters-e-g-p-value-confidence-intervals-from-a-turing-model-using-optim-jl/101433)

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**Author:** [@DominiqueMakowski](https://discourse.julialang.org/u/DominiqueMakowski)\
**Replies:** 3\
**Last updated:** [July 12, 2023, 9:11pm UTC](https://discourse.julialang.org/t/get-mle-parameters-e-g-p-value-confidence-intervals-from-a-turing-model-using-optim-jl/101433 "2023-07-12T21:11:03Z")

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EDIT: There is now PR to add this feature to Turing This might be a very silly question… but assuming the following simple linear model: using Turing using DataFrames using LinearAlgebra x = \[0, 1, 2, 3, 4, 5, 6, 7,…

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## [Streamplot - Streamlines in Julia](https://discourse.julialang.org/t/streamplot-streamlines-in-julia/101537)

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**Author:** [@Sisisi](https://discourse.julialang.org/u/Sisisi)\
**Replies:** 4\
**Last updated:** [July 12, 2023, 7:51pm UTC](https://discourse.julialang.org/t/streamplot-streamlines-in-julia/101537 "2023-07-12T19:51:16Z")

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Hello, I have this MATLAB code (arrays are examples) XX =\[0.0 0.0 0.0; 0.5 0.5 0.5; 1.0 1.0 1.0\]; YY = \[0.0 0.5 1.0; 0.0 0.5 1.0; 0.0 0.5 1.0\]; U = \[-0.0 -0.0 0.0; -0.0 -0.6 0.0; -0.0 -9.184850993605148e-17 0.0\]; V = \[…

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## [A way to add the iteration number on the callback function of Julia's NeuralPDE?](https://discourse.julialang.org/t/a-way-to-add-the-iteration-number-on-the-callback-function-of-julias-neuralpde/101507)

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**Author:** [@PeX](https://discourse.julialang.org/u/PeX)\
**Replies:** 2\
**Last updated:** [July 12, 2023, 6:31pm UTC](https://discourse.julialang.org/t/a-way-to-add-the-iteration-number-on-the-callback-function-of-julias-neuralpde/101507 "2023-07-12T18:31:44Z")

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I’m using NeuralPDE.jl to solve a system of nonlinear PDEs, following the example in the docs. I wonder if there is a way to add the iteration number in the callback function, so I will know the progress. The callback …

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## [Global Sensitivity Analysis in a subset of model parameters](https://discourse.julialang.org/t/global-sensitivity-analysis-in-a-subset-of-model-parameters/100666)

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**Author:** [@Nick1](https://discourse.julialang.org/u/Nick1)\
**Replies:** 4\
**Last updated:** [July 12, 2023, 4:45pm UTC](https://discourse.julialang.org/t/global-sensitivity-analysis-in-a-subset-of-model-parameters/100666 "2023-07-12T16:45:41Z")

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Hi everyone. I was wondering if there is a way to perform Global Sensitivity Analysis in a subset of model parameters, because some of them are physically constant. The most naive approach would be to set the lower and u…

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