# Specific Domains

**URL:** https://discourse.julialang.org/c/domain/10.md?page=403

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## [MethodError: no method matching \_parse\_NL\_expr\_runtime (Bilevel problem)](https://discourse.julialang.org/t/methoderror-no-method-matching-parse-nl-expr-runtime-bilevel-problem/51681)

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**Author:** [@trathi](https://discourse.julialang.org/u/trathi)\
**Replies:** 2\
**Last updated:** [December 12, 2020, 3:44am UTC](https://discourse.julialang.org/t/methoderror-no-method-matching-parse-nl-expr-runtime-bilevel-problem/51681 "2020-12-12T03:44:50Z")

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I am trying to solve a bilevel problem using the BilevelJuMP package. However, I get the following error on execution: MethodError: no method matching \_parse\_NL\_expr\_runtime(::BilevelJuMP.UpperModel, ::Int64, ::Array{JuM…

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## [How to index a JuMP variable during optimization](https://discourse.julialang.org/t/how-to-index-a-jump-variable-during-optimization/51658)

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**Author:** [@prit](https://discourse.julialang.org/u/prit)\
**Replies:** 3\
**Last updated:** [December 12, 2020, 2:48am UTC](https://discourse.julialang.org/t/how-to-index-a-jump-variable-during-optimization/51658 "2020-12-12T02:48:39Z")

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I have an undetermined (K) number of optimization problems to solve, and so far I have the following code to solve the K optimization problems. using JuMP using MosekTools m = Model(optimizer\_with\_attributes(Mosek.Optim…

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## [PyMC Models to Turing.jl](https://discourse.julialang.org/t/pymc-models-to-turing-jl/51574)

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**Author:** [@Stefan\_Bringuier](https://discourse.julialang.org/u/Stefan_Bringuier)\
**Replies:** 5\
**Last updated:** [December 11, 2020, 9:45pm UTC](https://discourse.julialang.org/t/pymc-models-to-turing-jl/51574 "2020-12-11T21:45:14Z")

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I’m learning (beginner) some Bayesian methods from books like Bayesian Methods for Hackers, C. Davidson-Pilon and Bayesian Analysis with Python. However, I prefer to do most of my workflows using Julia and I would like t…

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## [How to force variable to zero upon meeting condition in Julia DifferentialEquations](https://discourse.julialang.org/t/how-to-force-variable-to-zero-upon-meeting-condition-in-julia-differentialequations/51655)

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**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 19\
**Last updated:** [December 11, 2020, 5:54pm UTC](https://discourse.julialang.org/t/how-to-force-variable-to-zero-upon-meeting-condition-in-julia-differentialequations/51655 "2020-12-11T17:54:52Z")

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Hello, I have this model of bacteria and phage interactions: using DifferentialEquations function payneJansenODE!(du, u, p, t) μ , φ, η, β, ω = p H = h = 0 du\[1\] = (μ \* u\[1\]) - (φ \* u\[1\] \* u\[3\]) - (H \* u\[1\]…

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## [Several contour plots in one 3d plot](https://discourse.julialang.org/t/several-contour-plots-in-one-3d-plot/50986)

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**Author:** [@Flausi](https://discourse.julialang.org/u/Flausi)\
**Replies:** 5\
**Last updated:** [December 11, 2020, 2:35pm UTC](https://discourse.julialang.org/t/several-contour-plots-in-one-3d-plot/50986 "2020-12-11T14:35:14Z")

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Hello, is there a possibility in Julia to combine several contour plots into one 3D plot like in the picture? I have tried a little bit with GLMike, but did not get it. I would be very happy if there is a solution.

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## [How to use EnsembleDistributed() in DifferentialEquations.jl](https://discourse.julialang.org/t/how-to-use-ensembledistributed-in-differentialequations-jl/51642)

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**Author:** [@jmmm](https://discourse.julialang.org/u/jmmm)\
**Replies:** 2\
**Last updated:** [December 11, 2020, 10:07am UTC](https://discourse.julialang.org/t/how-to-use-ensembledistributed-in-differentialequations-jl/51642 "2020-12-11T10:07:48Z")

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I was following a tutorial in Stochastic Differential Equations · DifferentialEquations.jl (sciml.ai) and tried to modify it to use EnsembleDistributed() to speed up MC simulations. This is from the tutorial: using Dif…

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## [The objective function is not supported by JuMP](https://discourse.julialang.org/t/the-objective-function-is-not-supported-by-jump/51652)

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**Author:** [@prit](https://discourse.julialang.org/u/prit)\
**Replies:** 7\
**Last updated:** [December 11, 2020, 9:51am UTC](https://discourse.julialang.org/t/the-objective-function-is-not-supported-by-jump/51652 "2020-12-11T09:51:37Z")

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How to optimize a function in jump that contains an array in the objective function? I have the following constraint optimization problem in jump: m = Model(optimizer\_with\_attributes(Mosek.Optimizer, "QUIET" =\> false, …

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## [How can I use optim.jl to find some values](https://discourse.julialang.org/t/how-can-i-use-optim-jl-to-find-some-values/51317)

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**Author:** [@Lucas\_Pollito](https://discourse.julialang.org/u/Lucas_Pollito)\
**Replies:** 15\
**Last updated:** [December 11, 2020, 5:33am UTC](https://discourse.julialang.org/t/how-can-i-use-optim-jl-to-find-some-values/51317 "2020-12-11T05:33:31Z")

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I have some working code that i cant optmization to find some x\[1\] x\[2\] x\[3\] x\[4\] constants. A link for all the code is: https://drive.google.com/drive/folders/11cqtyUnWAoAYWdWyWOd6fbu4TVejbBlM?usp=sharing aRe = \[1.…

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## [Solving dynamic complementarity problem using Optim.jl or Complementarity.jl](https://discourse.julialang.org/t/solving-dynamic-complementarity-problem-using-optim-jl-or-complementarity-jl/51498)

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**Author:** [@jovansam](https://discourse.julialang.org/u/jovansam)\
**Replies:** 3\
**Last updated:** [December 11, 2020, 2:13am UTC](https://discourse.julialang.org/t/solving-dynamic-complementarity-problem-using-optim-jl-or-complementarity-jl/51498 "2020-12-11T02:13:20Z")

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I am interested in solving a dynamic complementarity problem using Complementarity.jl or Optim.jl. In particular I would appreciate some assistance in solving or how I could solve the following. A - B\*q\[t\] = λ\[t\] …

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## [Setting Knitro options](https://discourse.julialang.org/t/setting-knitro-options/51637)

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**Author:** [@Arega\_Getaneh](https://discourse.julialang.org/u/Arega_Getaneh)\
**Replies:** 1\
**Last updated:** [December 11, 2020, 12:33am UTC](https://discourse.julialang.org/t/setting-knitro-options/51637 "2020-12-11T00:33:21Z")

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I am using Knitro solver for MPEC problem. However, while solving, the solver exited before reaching the optimal decision and the information reads as EXIT: Problem appears to be unbounded. Iterate is feasible and objec…

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## [DiffEq and SVector](https://discourse.julialang.org/t/diffeq-and-svector/51541)

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**Author:** [@klaff](https://discourse.julialang.org/u/klaff)\
**Replies:** 16\
**Last updated:** [December 10, 2020, 11:11pm UTC](https://discourse.julialang.org/t/diffeq-and-svector/51541 "2020-12-10T23:11:57Z")

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Hello, I’ve been rereading some of the docs and tutorials in SciML and in particular this Optimizing DiffEq Code, and tried using StaticArrays as in the lorenz example, but on a problem of my own. In my case, the execut…

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## [Extracting JuMP results](https://discourse.julialang.org/t/extracting-jump-results/51429)

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**Author:** [@JohnZ](https://discourse.julialang.org/u/JohnZ)\
**Replies:** 6\
**Last updated:** [December 10, 2020, 10:25pm UTC](https://discourse.julialang.org/t/extracting-jump-results/51429 "2020-12-10T22:25:19Z")

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It seems like matrix multiplication does not work in the usual way with DenseAxisArray, If I use, ones(5,15)\*x using the code in the MWE it throws an error. Interestingly, array slicing ones(5,15)\[1,:\]'\*x works fine, b…

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## [Julia's FEM Landscape: where should DifferentialEquations go?](https://discourse.julialang.org/t/julias-fem-landscape-where-should-differentialequations-go/1592)

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**Author:** [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Replies:** 37\
**Last updated:** [December 10, 2020, 10:05pm UTC](https://discourse.julialang.org/t/julias-fem-landscape-where-should-differentialequations-go/1592 "2020-12-10T22:05:49Z")

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Hey, I am taking a good hard look at the Julia FEM landscape and would like some input. Let me first explain what I see the domain and scope of DifferentialEquations.jl. My work and research is centered around solving di…

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## [How to modulate the resolution of Julia DifferentialEquations solver](https://discourse.julialang.org/t/how-to-modulate-the-resolution-of-julia-differentialequations-solver/51561)

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**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 6\
**Last updated:** [December 10, 2020, 8:00pm UTC](https://discourse.julialang.org/t/how-to-modulate-the-resolution-of-julia-differentialequations-solver/51561 "2020-12-10T20:00:21Z")

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Hello, I have this model with delayed differential equations: using DifferentialEquations # function function baseInfect!(du, u, p, t) μ, κ, φ, ω, η, β = p du\[1\] = ((μ \* u\[1\]) \* (1 - ((u\[1\]+u\[2\])/κ))) - (φ \* u\[…

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## [Calculating Breaths Per Minute from Video Data](https://discourse.julialang.org/t/calculating-breaths-per-minute-from-video-data/51582)

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**Author:** [@RodBiren](https://discourse.julialang.org/u/RodBiren)\
**Replies:** 9\
**Last updated:** [December 10, 2020, 6:20pm UTC](https://discourse.julialang.org/t/calculating-breaths-per-minute-from-video-data/51582 "2020-12-10T18:20:32Z")

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I have been able to process video data of myself sleeping using a Wyze camera to produce fairly solid data that I would like to use to calculate breaths per minute.The actual calculation is trivial. I calculate the perce…

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## [Interpolation on non-rectangular domain](https://discourse.julialang.org/t/interpolation-on-non-rectangular-domain/51568)

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**Author:** [@Honza9723](https://discourse.julialang.org/u/Honza9723)\
**Replies:** 12\
**Last updated:** [December 10, 2020, 6:12pm UTC](https://discourse.julialang.org/t/interpolation-on-non-rectangular-domain/51568 "2020-12-10T18:12:08Z")

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Dear all, I would like to ask for advice, how to interpolate function on a non-rectangular domain. I am working on a problem, where the domain of my function is 2 or 3 dimensional, where all variables are restricted to …

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## [Modifying coefficient of quadratic term in objective function](https://discourse.julialang.org/t/modifying-coefficient-of-quadratic-term-in-objective-function/51622)

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**Author:** [@guilhermebodin](https://discourse.julialang.org/u/guilhermebodin)\
**Replies:** 1\
**Last updated:** [December 10, 2020, 5:59pm UTC](https://discourse.julialang.org/t/modifying-coefficient-of-quadratic-term-in-objective-function/51622 "2020-12-10T17:59:17Z")

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Suppose I have this problem: using JuMP, OSQP m = Model(OSQP.Optimizer) @variable(m, x\[1:3\] \>= 0) @constraint(m, sum(x) .\>= 1) @objective(m, Min, x\[1\] + 2x\[2\] + 3x\[3\]^2 + 2x\[1\]^2) optimize!(m) objective\_value(m) I can …

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## [DifferentialEquations.jl: Complex function results in Inexact Error](https://discourse.julialang.org/t/differentialequations-jl-complex-function-results-in-inexact-error/51591)

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**Author:** [@ess3sq](https://discourse.julialang.org/u/ess3sq)\
**Replies:** 5\
**Last updated:** [December 10, 2020, 12:57pm UTC](https://discourse.julialang.org/t/differentialequations-jl-complex-function-results-in-inexact-error/51591 "2020-12-10T12:57:50Z")

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I am trying to solve a one dimensional Schrödinger equation which has been reduced to a first-order linear ODE of the kind \\psi’(x) = f(x) \\psi(x), where all functions have complex args (Complex{Float64}) I believe. Eit…

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## [How to debug ODE](https://discourse.julialang.org/t/how-to-debug-ode/50576)

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**Author:** [@Luigi\_Marongiu](https://discourse.julialang.org/u/Luigi_Marongiu)\
**Replies:** 14\
**Last updated:** [December 10, 2020, 6:59am UTC](https://discourse.julialang.org/t/how-to-debug-ode/50576 "2020-12-10T06:59:22Z")

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Hello, I have a set of ODEs to model a bacterial infection: function kinInfect!(du, u, p, t) μ , φ, η, β, ω, χ, ε = p H = h = 0 #= du\[1\] = susceptible du\[2\] = infected du\[3\] = phages μ…

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## [Add constraints in parallel](https://discourse.julialang.org/t/add-constraints-in-parallel/51382)

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**Author:** [@cyanzhao42](https://discourse.julialang.org/u/cyanzhao42)\
**Replies:** 2\
**Last updated:** [December 10, 2020, 6:39am UTC](https://discourse.julialang.org/t/add-constraints-in-parallel/51382 "2020-12-10T06:39:27Z")

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Hi all, I am wondering can I add constraints to one model in parallel? The constraints is added via a for-loop. Thanks!

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## [Learning non-linear spatio-temporal dynamics with convolutional Neural ODEs](https://discourse.julialang.org/t/learning-non-linear-spatio-temporal-dynamics-with-convolutional-neural-odes/51448)

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**Author:** [@johnh](https://discourse.julialang.org/u/johnh)\
**Replies:** 1\
**Last updated:** [December 10, 2020, 4:42am UTC](https://discourse.julialang.org/t/learning-non-linear-spatio-temporal-dynamics-with-convolutional-neural-odes/51448 "2020-12-10T04:42:27Z")

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I work for Dell, but am not involved. @ChrisRackauckas please tell us this is all written in Julia… https://ml4physicalsciences.github.io/2020/files/NeurIPS\_ML4PS\_2020\_125.pdf

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## [How to make a custom (/manual) legend with Plots.jl?](https://discourse.julialang.org/t/how-to-make-a-custom-manual-legend-with-plots-jl/51579)

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**Author:** [@bvilmann](https://discourse.julialang.org/u/bvilmann)\
**Replies:** 0\
**Last updated:** [December 10, 2020, 2:45am UTC](https://discourse.julialang.org/t/how-to-make-a-custom-manual-legend-with-plots-jl/51579 "2020-12-10T02:45:30Z")

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Dear community! I want to make a common (/manual) legend for my plot for the various “types” of production units. How do I do that with Plots? My code is something similar to: groupedbar( hcat(C'-P', P',zeros(N…

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## [Which solver/model library can be used recursively / reentrantly](https://discourse.julialang.org/t/which-solver-model-library-can-be-used-recursively-reentrantly/51294)

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**Author:** [@xyz1](https://discourse.julialang.org/u/xyz1)\
**Replies:** 2\
**Last updated:** [December 9, 2020, 8:47pm UTC](https://discourse.julialang.org/t/which-solver-model-library-can-be-used-recursively-reentrantly/51294 "2020-12-09T20:47:48Z")

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Hello, my code currently consists of a recursive function f and I am planning on using an optimization solver (global optimization for integer programming with binary variables) for solving a sub-problem of the function f…

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## [Manually defined partially conjugate update step](https://discourse.julialang.org/t/manually-defined-partially-conjugate-update-step/51299)

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**Author:** [@fmeulen](https://discourse.julialang.org/u/fmeulen)\
**Replies:** 2\
**Last updated:** [December 9, 2020, 8:05pm UTC](https://discourse.julialang.org/t/manually-defined-partially-conjugate-update-step/51299 "2020-12-09T20:05:05Z")

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I have a model where I can apply Turing to the full parameter vector, that seems to work. However, I can partition the parameter such that a Gibbs sampler can be devised where one parameter is updated in a partially conj…

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## [Performance regression with GPUArrays subset sum](https://discourse.julialang.org/t/performance-regression-with-gpuarrays-subset-sum/50767)

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**Author:** [@eaubanel](https://discourse.julialang.org/u/eaubanel)\
**Replies:** 9\
**Last updated:** [December 9, 2020, 7:20pm UTC](https://discourse.julialang.org/t/performance-regression-with-gpuarrays-subset-sum/50767 "2020-12-09T19:20:23Z")

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I’ve been away from Julia for several months, and have been rerunning GPU code from this past summer on a new installation of Jula 1.5.3 and CUDA.jl (previously I used the separate CUDA packages). My subset sum program n…

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## [NLSolve performance 32 vs 64 bits](https://discourse.julialang.org/t/nlsolve-performance-32-vs-64-bits/51515)

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**Author:** [@bdc](https://discourse.julialang.org/u/bdc)\
**Replies:** 1\
**Last updated:** [December 9, 2020, 12:18pm UTC](https://discourse.julialang.org/t/nlsolve-performance-32-vs-64-bits/51515 "2020-12-09T12:18:45Z")

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Hi, For an application with NLsolve.jl I ran into an OutOfMemoryError(), so I decided to try using single instead of double precision in order to reduce the memory footprint (approach similar to machine learning on GPU’…

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## [Random number in (0,1)](https://discourse.julialang.org/t/random-number-in-0-1/51451)

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**Author:** [@jherekhealy](https://discourse.julialang.org/u/jherekhealy)\
**Replies:** 9\
**Last updated:** [December 9, 2020, 10:38am UTC](https://discourse.julialang.org/t/random-number-in-0-1/51451 "2020-12-09T10:38:22Z")

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In Random.jl, there is the possibility to generate a random number in the interval \[0,1) through CloseOpen01, or even in \[1,2) (I can see the reason for this for implementation, less so for a user) through CloseOpen12, …

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## [Trying to solve a second order differential equation. Your advices](https://discourse.julialang.org/t/trying-to-solve-a-second-order-differential-equation-your-advices/41162)

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**Author:** [@aquarelle332](https://discourse.julialang.org/u/aquarelle332)\
**Replies:** 19\
**Last updated:** [December 9, 2020, 7:40am UTC](https://discourse.julialang.org/t/trying-to-solve-a-second-order-differential-equation-your-advices/41162 "2020-12-09T07:40:15Z")

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Hello dear all, I don’t know whether it is the right place to post what follows… I am trying to resolve a differential equation like (namely Rayleigh-Plesset eq): R\*d²R/dt²+3/2\*dR/dt=P where P is a constant, say. Pre…

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## [Packages for interval and radius of power series](https://discourse.julialang.org/t/packages-for-interval-and-radius-of-power-series/51230)

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**Author:** [@brett\_knoss](https://discourse.julialang.org/u/brett_knoss)\
**Replies:** 24\
**Last updated:** [December 8, 2020, 6:06pm UTC](https://discourse.julialang.org/t/packages-for-interval-and-radius-of-power-series/51230 "2020-12-08T18:06:14Z")

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What packages exist for studying power series(not sure the plural)? I’m trying to find the formula that originated the series, as well as the radius and interval of convergence.

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## [\[Solved\] Time evaluation issue in a non-autonomous ODE](https://discourse.julialang.org/t/solved-time-evaluation-issue-in-a-non-autonomous-ode/51458)

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**Author:** [@Wen-Wei\_Tseng](https://discourse.julialang.org/u/Wen-Wei_Tseng)\
**Replies:** 2\
**Last updated:** [December 8, 2020, 2:09pm UTC](https://discourse.julialang.org/t/solved-time-evaluation-issue-in-a-non-autonomous-ode/51458 "2020-12-08T14:09:22Z")

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Hello everyone, I found a weird situation that a time-dependent parameter seemed to be ignored in my calcium dynamics model. After some trimming, I had an MWE here. Any suggestions/corrections are welcome. Edit: solved …

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