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Questions tagged [newtons-method]

In numerical analysis, Newton's method (also known as the Newton–Raphson method) is a method for finding successively better approximations to the roots (or zeroes) of a real-valued function.

In numerical analysis, Newton's method (also known as the Newton–Raphson method) is a method for finding successively better approximations to the roots (or zeroes) of a real-valued function.

Formula:

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In this formula xn + 1 is the next closest approximation after xn, f(xn) is the function at xn and f'(xn) is the derivative of the function at xn.

First approximation x0 has to be in interval (a,b) where exact solution x* is situated.

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solving a simple (?) system of nonlinear equations

I'm trying to solve a simple system of non-linear equations described in this post. The system is two equations with two unknowns p and q and a free parameter lambda: When lambda = 1 the system looks like this: There is a unique solution and it's…
invictus
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Implementing Multivariate Newton's Method in Julia

I am attempting to implement the multivariate Newton's method in Julia, but have run into a "no metehod matching" error. Below is my implementation and the code I use to call it. function newton(f::Vector, J::Matrix, x::Vector) h = Inf64 …
K. Claesson
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Update step in PyTorch implementation of Newton's method

I'm trying to get some insight into how PyTorch works by implementing Newton's method for solving x = cos(x). Here's a version that works: x = Variable(DoubleTensor([1]), requires_grad=True) for i in range(5): y = x - torch.cos(x) …
fmg
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R loop to approximate square root of a positive real number with Newton's method

I am new to R and I'm working on a homework question which asks me to use a repeat loop using Newton's method for square root approximation. Here is what I have so far: x = 2 a = 10 tol = 1e-04 repeat { (abs(x^2 - a) > tol) (x = 0.5 * (a/x +…
Bkk
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Python: Newton, Hessian, Jacobian Method

Hi I am trying to use newton method to minimise a function but I keep getting this error when I run the code and I don't know why. Any help is much appreciated. Thanks! Error: ValueError: shapes (2,1) and (2,1) not aligned: 1 (dim 1) != 2 (dim 0) …
Nu2prog
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root-finding algorithm for a complex polynomial equation in python

I am trying to solve for the following equation with a simple algorithm. I am not sure if the algorithm that I'm using is the best one or not but it is the only way that I could think of. In this equation, everything other than P is known, and I…
Nikki
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Newton Raphson: Can the user input the function?

[This image here is my python code for the Newton-Raphson method. The problem is with the mathematical function and the derivative. At the moment I am the one who specifies the function and its derivative. Is there any way to get the user to input…
Victor Reaver
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Why is my code implementing the Fisher scoring algorithm failing to converge?

# Set data sets data <- MASS::birthwt X <- as.matrix(cbind(1, data[, -1])) Y <- data[, 1] n <- dim(X)[1] p <- dim(X)[2] beta <- rep(0, p) # Initialize beta beta1 <- rep(1, p) # Initialize beta1 # fit logit regression using Fisher…
Xingzhe He
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Newton method in python / scipy

i am trying to get root of a function using Newton's algorithm on python. I have a runtime error even if i change the precision level. can you kindly help me understand how can i improve it? Best, GB Below my 'simple' code and the root finding…
phacoo
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newton.optimize TypeError: 'float' object is not subscriptable

I am running the code below and receiving message error "TypeError: 'float' object is not subscriptable". I simplified it in order to make clear. The main issue comes from the function that is called to newton optimization. Can't find the reason.…
Ricardo
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Newton's Raphsons Method Java

I wanted to tabulate my data for Newtons Raphsons Method only for quadratic equations in neat array something like. What I am having difficulty doing is allocating the variables in the array, allocating the previous value of xn1 to the xn value in…
Fahad Shaikh
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NOT CONVERGE: use Newton Raphson-Method to find root of nonlinear equations

I tried non-linear polynomial functions and this code works well. But for this one I tried several methods to solve the linear equation df0*X=f0 using backslash or bicg or lsqr, also tried several initial values but the result never converge. %…
Jarvis
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Newtonraphson code in R leads to different results

I need to approximate the parameters of a sample from Birnbaum-Saunders distr. here is my code: x =c(6.7508, 1.9345, 4.9612, 22.0232, 0.2665, 66.7933, 5.5582, 60.2324, 72.5214, 1.4188, 4.6318, 61.8093, 11.3845, 1.1587, 22.8475, 8.3223, 2.6085,…
Lola
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Error using std::bind and std::function in C++

I attempt to try my snippet of Newton's method on a multivariate function and used std::bind and std::function. But I was stuck on an error error: conversion from 'std::_Bind_helper&, int>::type {aka std::_Bind, int))(double, double, double)>}'…
Nicholas
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Seeding square roots on FPGA in VHDL for Fixed Point

I'm attempting to create a fixed-point square root function for a Xilinx FPGA (hence real types are out, and David Bishops ieee_proposed library is also unsupported for XST synthesis). I've settled on a Newton-Raphson method to calculate the…
davidhood2
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