Finding Jacobian matrix for Newton's method

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.

Answer 1

[Walter Roberson]

If you have the symbolic toolbox you can use the jacobian() function.

[Jenn Lee]

is there a way to code this?

[Walter Roberson]

x = sym('x', [1 2]);
eqn = [2*x(1) + x(2)
       3*x(1) + x(2)^2];
jacobian(eqn, x)

Answer 2

[DIPANKAR POREY]

2x(1) + x(2)
3x(1) + x(2)^2
=> Jac(x) =
[2, 1; 3, 2x(2)]

[Walter Roberson]

This does not appear to be an answer? It appears to be a copy of part of the question.