# \#nlsolve

**URL:** https://discourse.julialang.org/tag/nlsolve/441.md

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## [Any member of the JuliaNLSolvers organization here?](https://discourse.julialang.org/t/any-member-of-the-julianlsolvers-organization-here/135722)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 10\
**Last updated:** [February 24, 2026, 7:30pm UTC](https://discourse.julialang.org/t/any-member-of-the-julianlsolvers-organization-here/135722 "2026-02-24T19:30:11Z")

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Is there anyone from the JuliaNLSolvers organization here? I see the organization has only two members: JuliaNLSolvers · GitHub Perhaps a good time to look for additional members? Someone should approve this workflow: h…

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## [Bug in NLSolve](https://discourse.julialang.org/t/bug-in-nlsolve/135660)

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**Author:** [@ufechner7](https://discourse.julialang.org/u/ufechner7)\
**Replies:** 8\
**Last updated:** [February 16, 2026, 6:37pm UTC](https://discourse.julialang.org/t/bug-in-nlsolve/135660 "2026-02-16T18:37:11Z")

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I had a very ugly bug for more than a year. Now, thanks to AI, I found the reason and could fix it. This bug was very ugly at first, because it does not always appear, only for certain numerical values. And secondly, no…

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## [Getting to zero allocations in NonlinearSolve.jl](https://discourse.julialang.org/t/getting-to-zero-allocations-in-nonlinearsolve-jl/123123)

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**Author:** [@rafaelbailo](https://discourse.julialang.org/u/rafaelbailo)\
**Replies:** 9\
**Last updated:** [November 29, 2024, 6:05am UTC](https://discourse.julialang.org/t/getting-to-zero-allocations-in-nonlinearsolve-jl/123123 "2024-11-29T06:05:30Z")

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I am in the process of migrating some code from NLsolve.jl to NonlinearSolve.jl. I have written a simple Newton-Raphson test, but I cannot get the allocations down to zero; both solve! and reinit! allocate. Can this be i…

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## [Implementation implicit Gauss method](https://discourse.julialang.org/t/implementation-implicit-gauss-method/118912)

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**Author:** [@khaledharizb](https://discourse.julialang.org/u/khaledharizb)\
**Replies:** 5\
**Last updated:** [September 1, 2024, 11:34pm UTC](https://discourse.julialang.org/t/implementation-implicit-gauss-method/118912 "2024-09-01T23:34:18Z")

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I would like to implement Runge Kutta Gauss method. This method is implicit and need a nonlinear solver to do so. For that I define a fixed point solver FixIter, then the function Gauss(f::Function,u₀,h,N) using Linear…

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## [Implicit numerical method using NLsolve.jl](https://discourse.julialang.org/t/implicit-numerical-method-using-nlsolve-jl/118525)

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**Author:** [@khaledharizb](https://discourse.julialang.org/u/khaledharizb)\
**Replies:** 3\
**Last updated:** [August 23, 2024, 11:13am UTC](https://discourse.julialang.org/t/implicit-numerical-method-using-nlsolve-jl/118525 "2024-08-23T11:13:33Z")

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I would like to implement Lobatto IIIA-IIIB which is an implicit method. To do so, a non-linear equations need to be solved. Then I used NLsolve.jl for my problem using NLsolve function NuMethod(fV::Function,fT::Func…

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## [Error for solving ODEs by an implicit RK methods when using NLsolve.jl](https://discourse.julialang.org/t/error-for-solving-odes-by-an-implicit-rk-methods-when-using-nlsolve-jl/107764)

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**Author:** [@khaledharizb](https://discourse.julialang.org/u/khaledharizb)\
**Replies:** 1\
**Last updated:** [December 18, 2023, 9:36pm UTC](https://discourse.julialang.org/t/error-for-solving-odes-by-an-implicit-rk-methods-when-using-nlsolve-jl/107764 "2023-12-18T21:36:03Z")

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Hi Guys!, I’m trying to an ODE system using implicit RK method. Defining the following system \\dot q\_i=p\_i,\\quad \\dot p\_i = -\\frac{q\_i}{||q||^3} and here q,p\\in \\mathbb R^3. I’m using this code using NLsolve function…

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## [Type problems in ForwardDiff with preallocations](https://discourse.julialang.org/t/type-problems-in-forwarddiff-with-preallocations/118131)

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**Author:** [@Chandrasekhar](https://discourse.julialang.org/u/Chandrasekhar)\
**Replies:** 2\
**Last updated:** [August 13, 2024, 12:32pm UTC](https://discourse.julialang.org/t/type-problems-in-forwarddiff-with-preallocations/118131 "2024-08-13T12:32:46Z")

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Hi everyone! I am solving a system of non-linear equations by using nlsolve. I want to use ForwardDiff to calculate the Jacobian inside nlsolve. The code which is running without any errors is the following: function g…

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## [Optimization with integrals in both objective and the constraint](https://discourse.julialang.org/t/optimization-with-integrals-in-both-objective-and-the-constraint/113838)

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**Author:** [@Ayesha](https://discourse.julialang.org/u/Ayesha)\
**Replies:** 9\
**Last updated:** [May 9, 2024, 11:54pm UTC](https://discourse.julialang.org/t/optimization-with-integrals-in-both-objective-and-the-constraint/113838 "2024-05-09T23:54:36Z")

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I’m trying to optimize a function that has an integral in the objective. While I can perform unconstrained optimization, I’m unsure how to use the Julia optimizer. I am trying to do this to add a constraint later, which …

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## [Modeling and solving systems of nonlinear dynamic equations](https://discourse.julialang.org/t/modeling-and-solving-systems-of-nonlinear-dynamic-equations/108556)

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**Author:** [@enzo.salvatore](https://discourse.julialang.org/u/enzo.salvatore)\
**Replies:** 11\
**Last updated:** [January 17, 2024, 3:48pm UTC](https://discourse.julialang.org/t/modeling-and-solving-systems-of-nonlinear-dynamic-equations/108556 "2024-01-17T15:48:08Z")

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I am currently a Ph.D. student in economics, and I am looking to find a way to model and solve dynamic systems of nonlinear equations. The goal is to create a dynamic Computable General Equilibrium (CGE) model in Julia. …

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## [How to deal with vectors in NLsolve.jl](https://discourse.julialang.org/t/how-to-deal-with-vectors-in-nlsolve-jl/107488)

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**Author:** [@khaledharizb](https://discourse.julialang.org/u/khaledharizb)\
**Replies:** 2\
**Last updated:** [December 17, 2023, 9:49pm UTC](https://discourse.julialang.org/t/how-to-deal-with-vectors-in-nlsolve-jl/107488 "2023-12-17T21:49:17Z")

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Hi guys! I didn’t find a way to deal with vector using pkg NLSolve in the following problem. Let q=\[x,y\] and p=\[u,v\] and defining the functions f and g as f(q) = q / (√(q'\*q))^3,\\ g(p) = p. Now, giving q\_0=\[0.4,0\] an…

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## [Solving F(X)=0 using nlsolve](https://discourse.julialang.org/t/solving-f-x-0-using-nlsolve/105516)

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**Author:** [@havana](https://discourse.julialang.org/u/havana)\
**Replies:** 6\
**Last updated:** [October 28, 2023, 9:29pm UTC](https://discourse.julialang.org/t/solving-f-x-0-using-nlsolve/105516 "2023-10-28T21:29:38Z")

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I wanna solve a root finding problem of the form F(X)=0 using NLsolve. However, I do not know the regularity of the function F, for example if it is not differentiable, so the Jacobian does not exists, how do the functi…

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## [I am seeing strange behavior in NLsolve package. Mutating function is not working](https://discourse.julialang.org/t/i-am-seeing-strange-behavior-in-nlsolve-package-mutating-function-is-not-working/104359)

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**Author:** [@Shashank](https://discourse.julialang.org/u/Shashank)\
**Replies:** 2\
**Last updated:** [September 28, 2023, 4:45pm UTC](https://discourse.julialang.org/t/i-am-seeing-strange-behavior-in-nlsolve-package-mutating-function-is-not-working/104359 "2023-09-28T16:45:57Z")

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I am trying to optimize a function that has several contributions. So I need to add several terms to it, but when I pass that function to nlsolve I am getting strange results. I have reproduced a minimal example that rep…

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## [Adaptation of NLsolve for function with vector output](https://discourse.julialang.org/t/adaptation-of-nlsolve-for-function-with-vector-output/103139)

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**Author:** [@Outeirom](https://discourse.julialang.org/u/Outeirom)\
**Replies:** 4\
**Last updated:** [August 24, 2023, 8:07pm UTC](https://discourse.julialang.org/t/adaptation-of-nlsolve-for-function-with-vector-output/103139 "2023-08-24T20:07:56Z")

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I’m facing an issue with NLSolve. I have two interacting functions that are working well, and I need to adapt them. Let me briefly summarize how the functions are currently set up and what I’m aiming to achieve. Firstly…

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## [Speed up solution of large system of equations](https://discourse.julialang.org/t/speed-up-solution-of-large-system-of-equations/102659)

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**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 18\
**Last updated:** [August 19, 2023, 3:19pm UTC](https://discourse.julialang.org/t/speed-up-solution-of-large-system-of-equations/102659 "2023-08-19T15:19:48Z")

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I have a system of equations: \\begin{aligned} & S^m\_{a\_m, e\_m}-\\mu^{0m}\_{a\_m, e\_m}=\\sum\_{a\_m=1}^{46} {\\Pi}\_{a\_m, e\_m, a\_f, e\_f}\\sqrt{S^m\_{a\_m, e\_m} S^f\_{a\_f, e\_f}} \\prod\_{k=0}^{T(a\_m, a\_f)-1}\\left(\\frac{\\mu^{0m}\_{a\_m+k…

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## [Obtain jacobian used by NLsolve](https://discourse.julialang.org/t/obtain-jacobian-used-by-nlsolve/101532)

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**Author:** [@PABLO\_ESTEBAN\_MONTES](https://discourse.julialang.org/u/PABLO_ESTEBAN_MONTES)\
**Replies:** 2\
**Last updated:** [July 12, 2023, 3:08pm UTC](https://discourse.julialang.org/t/obtain-jacobian-used-by-nlsolve/101532 "2023-07-12T15:08:16Z")

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Hello, I have a function, let’s call it f!, whose zero I’m trying to find by using the Newton method. I know that the package NLsolve allows me to do this either giving it the jacobian, with something of the form nlsolv…

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## [ODE solving](https://discourse.julialang.org/t/ode-solving/99520)

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**Author:** [@Ordens\_Ritter](https://discourse.julialang.org/u/Ordens_Ritter)\
**Replies:** 7\
**Last updated:** [May 30, 2023, 8:48pm UTC](https://discourse.julialang.org/t/ode-solving/99520 "2023-05-30T20:48:03Z")

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I am Trying to model some temperature curves with a physically informed NN (PINN). I started solve the FOPDT first, to be able to apply it later. function FOPDT(z) τ, Κ, θ = z return \[T1\[i\] .- (1 ./ τ) .\* (-T1…

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## [Nelder-Mead or other optimization](https://discourse.julialang.org/t/nelder-mead-or-other-optimization/98853)

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**Author:** [@papar](https://discourse.julialang.org/u/papar)\
**Replies:** 5\
**Last updated:** [May 16, 2023, 9:28pm UTC](https://discourse.julialang.org/t/nelder-mead-or-other-optimization/98853 "2023-05-16T21:28:42Z")

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I am trying to use Optim to find parameters of a vector valued function using the Nelder-Mead algorithm, but open to considering other algorithms or packages. The problem is to find parameters of a function by minimizing…

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## [No result from nlsolve](https://discourse.julialang.org/t/no-result-from-nlsolve/98325)

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**Author:** [@cdestael](https://discourse.julialang.org/u/cdestael)\
**Replies:** 2\
**Last updated:** [May 4, 2023, 4:53pm UTC](https://discourse.julialang.org/t/no-result-from-nlsolve/98325 "2023-05-04T16:53:09Z")

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Below is a MWE of a problem I am working with. First, a function is defined with a system of 4 equations. Second, matrices are initialized. Third, I try to solve the system using nlsolve. After running this MWE, the c…

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## [Using DiffEqBase.NLSolveTerminationCondition in NonlinearSolve.jl](https://discourse.julialang.org/t/using-diffeqbase-nlsolveterminationcondition-in-nonlinearsolve-jl/97873)

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**Author:** [@psterzinger](https://discourse.julialang.org/u/psterzinger)\
**Replies:** 4\
**Last updated:** [April 25, 2023, 7:10am UTC](https://discourse.julialang.org/t/using-diffeqbase-nlsolveterminationcondition-in-nonlinearsolve-jl/97873 "2023-04-25T07:10:16Z")

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I am trying to solve a system of three nonlinear equations and would like to use the termination conditions provided by DiffEqBase.NLSolveTerminationCondition (see the documentation of NonlinearSolve.jl. The function de…

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## [Is there a reliable package for solving simple equation system?](https://discourse.julialang.org/t/is-there-a-reliable-package-for-solving-simple-equation-system/94877)

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**Author:** [@Kim](https://discourse.julialang.org/u/Kim)\
**Replies:** 4\
**Last updated:** [February 19, 2023, 8:14pm UTC](https://discourse.julialang.org/t/is-there-a-reliable-package-for-solving-simple-equation-system/94877 "2023-02-19T20:14:20Z")

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Today I am working on finding the insections of a line and a infinite long cylinder. It is a simple math problem that can be solved by hand and very easy for Matlab. However, it looks like tough for Julia which is inspir…

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## [Solve system of non-linear equation](https://discourse.julialang.org/t/solve-system-of-non-linear-equation/94706)

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**Author:** [@Students](https://discourse.julialang.org/u/Students)\
**Replies:** 4\
**Last updated:** [February 16, 2023, 6:26am UTC](https://discourse.julialang.org/t/solve-system-of-non-linear-equation/94706 "2023-02-16T06:26:34Z")

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Hello, I am trying to find the stationary point (gradient g(x) = 0) of this func: I am new to Julia! I understand that I should use NLsolve package to solve system of nonlinear eq. Could you please tell me how to tak…

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## [Find zero of a nonlinear equation using Julia](https://discourse.julialang.org/t/find-zero-of-a-nonlinear-equation-using-julia/61974)

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**Author:** [@maoc](https://discourse.julialang.org/u/maoc)\
**Replies:** 14\
**Last updated:** [January 7, 2023, 12:47am UTC](https://discourse.julialang.org/t/find-zero-of-a-nonlinear-equation-using-julia/61974 "2023-01-07T00:47:16Z")

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After a process usyng the SymPy in Julia, I generated a system of nonlinear equations. For the sake of simplicity, I am going to put an approximation here for the case of just a non-linear equation. What I get is somethi…

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## [Problem with NLSolve: cant find x st f(x) =0](https://discourse.julialang.org/t/problem-with-nlsolve-cant-find-x-st-f-x-0/88345)

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**Author:** [@Outeirom](https://discourse.julialang.org/u/Outeirom)\
**Replies:** 4\
**Last updated:** [October 6, 2022, 4:39pm UTC](https://discourse.julialang.org/t/problem-with-nlsolve-cant-find-x-st-f-x-0/88345 "2022-10-06T16:39:52Z")

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So, I have a code in matlab and I am trying to translate it to Julia. Im not being able to run this NLSolve in Julia. It returns me a domain error… probably because there is x^eta, where eta = 0.5. But what makes no se…

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## [Using nlsolve for roots of Legendre Polynomials in terms of RadauIIA method](https://discourse.julialang.org/t/using-nlsolve-for-roots-of-legendre-polynomials-in-terms-of-radauiia-method/84872)

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**Author:** [@Vick](https://discourse.julialang.org/u/Vick)\
**Replies:** 0\
**Last updated:** [July 27, 2022, 1:04pm UTC](https://discourse.julialang.org/t/using-nlsolve-for-roots-of-legendre-polynomials-in-terms-of-radauiia-method/84872 "2022-07-27T13:04:31Z")

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Hi, I need to find root for Legendre polynomials in terms of the RadauIIA method using ClassicalOrthogonalPolynomials, NLsolve function P(x, n) return legendrep(n, x) end function radc(x, s) v = 2 \* x - 1 …

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## [Understanding NLSolvers Package through the Given Documentation](https://discourse.julialang.org/t/understanding-nlsolvers-package-through-the-given-documentation/82512)

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**Author:** [@MJF](https://discourse.julialang.org/u/MJF)\
**Replies:** 0\
**Last updated:** [June 9, 2022, 4:22pm UTC](https://discourse.julialang.org/t/understanding-nlsolvers-package-through-the-given-documentation/82512 "2022-06-09T16:22:07Z")

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I am quite new to Julia and trying to figure out how to use the NLSolvers package as given in the following link: NLSolvers In the README file, they provide an example for a nonlinear system of equations for the Rosenbr…

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## [NLsolve.jl for different input and output dimensions?](https://discourse.julialang.org/t/nlsolve-jl-for-different-input-and-output-dimensions/80202)

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**Author:** [@Alseidon](https://discourse.julialang.org/u/Alseidon)\
**Replies:** 13\
**Last updated:** [May 2, 2022, 3:13pm UTC](https://discourse.julialang.org/t/nlsolve-jl-for-different-input-and-output-dimensions/80202 "2022-05-02T15:13:29Z")

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Hi all, I am currently trying out NLsolve.jl to find roots of given functions, which works great at the moment, but I realized that I can’t seem to find a way to specify a dimension for the output different from the inp…

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## [Modify custom solver to deal with multidimensional arrays](https://discourse.julialang.org/t/modify-custom-solver-to-deal-with-multidimensional-arrays/74845)

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**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 10\
**Last updated:** [March 2, 2022, 11:57am UTC](https://discourse.julialang.org/t/modify-custom-solver-to-deal-with-multidimensional-arrays/74845 "2022-03-02T11:57:59Z")

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Some time ago @longemen3000 shared with me his custom nl equation solver written with NLSolvers here. It works well when the system is provided as a vector. I tried to modify it to accept systems provided with multidimen…

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## [Help optimizing IPFP algorithm](https://discourse.julialang.org/t/help-optimizing-ipfp-algorithm/74376)

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**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 6\
**Last updated:** [January 13, 2022, 3:56am UTC](https://discourse.julialang.org/t/help-optimizing-ipfp-algorithm/74376 "2022-01-13T03:56:38Z")

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I’m trying to speed up this version of the IPFP algorithm, which alternates between solving 2 systems of nonlinear equations until convergence: using NLsolve using LinearAlgebra const szAge = 64 - 19 + 1 const szE = 2 …

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## [What nonlinear solvers are available?](https://discourse.julialang.org/t/what-nonlinear-solvers-are-available/69801)

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**Author:** [@amrods](https://discourse.julialang.org/u/amrods)\
**Replies:** 10\
**Last updated:** [January 11, 2022, 5:37am UTC](https://discourse.julialang.org/t/what-nonlinear-solvers-are-available/69801 "2022-01-11T05:37:56Z")

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I am trying to test nonlinear systems solvers, preferably with lots of available algorithms (analogous to the packages Optim.jl and NLopt.jl for optimization). I know of NLsolve.jl, IntervalRootFinding.jl, and NonlinearS…

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## [Finding multiple fixed points of a non-linear problem](https://discourse.julialang.org/t/finding-multiple-fixed-points-of-a-non-linear-problem/72292)

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**Author:** [@Joseph\_Bradley](https://discourse.julialang.org/u/Joseph_Bradley)\
**Replies:** 3\
**Last updated:** [November 30, 2021, 1:50pm UTC](https://discourse.julialang.org/t/finding-multiple-fixed-points-of-a-non-linear-problem/72292 "2021-11-30T13:50:25Z")

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Hi! I’m looking for some Julia code that will find all the fixed points of a non-linear problem. Specifically, I’m looking for all the solutions of this fixed point problem: m = tanh(am + b) where a and b are paramete…

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