Finding Jacobian matrix for Newton's method

20 次查看（过去 30 天）
Jenn Lee
Jenn Lee 2012-4-13
评论： Walter Roberson 2019-8-8
I have a very basic newton's method that uses a loop and:
y = Jac(x)\(-F(x));
x = x + y;
to solve for the approximate solution.
Where x is a the initial guess in the form of a vector, F is the nonlinear function, and Jac is the jacobian matrix. Currently, I am inputting the jacobian by hand.
For example, system of equations =
2x(1) + x(2)
3x(1) + x(2)^2
=> Jac(x) =
[2, 1; 3, 2x(2)]
I was wondering if instead of solving it by hand if I could get Matlab to do it for me.

请先登录，再回答此问题。

采纳的回答

Walter Roberson
Walter Roberson 2012-4-13
If you have the symbolic toolbox you can use the jacobian() function.

更多回答（1 个）

DIPANKAR POREY
DIPANKAR POREY 2019-8-7
2x(1) + x(2)
3x(1) + x(2)^2
=> Jac(x) =
[2, 1; 3, 2x(2)]
  1 个评论
Walter Roberson
Walter Roberson 2019-8-8
This does not appear to be an answer? It appears to be a copy of part of the question.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Operating on Diagonal Matrices 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by