What to change in code?

Hello Experts,

Given the following code:

http://www.mathworks.com/matlabcentral/fileexchange/2305-numerical-methods-using-matlab-2e/content/edition2/na_funcs/bairstow.m

How to transform it to work with the full polynomial, not from a(1).

I really need someone to help me with this issue urgently.

Thanks in advance!

[bym]

what do you mean full polynomial,not from a(1)?

[bym]

whats wrong with answers here? http://www.mathworks.com/matlabcentral/answers/17931-bairstow-method-to-find-polynomial-roots-matlab-code-problem

[Steve]

Hello proecsm,

Thanks for commenting, I am going to publish the problem and what I have done, so please be so kind and help me.

Answer 1

[Wayne King]

Steve, I have the same question proecsm asks, what's wrong with the answer Walter and I gave you in your earlier post? If you want the roots of:

p(x) = 2*x^2+2*x+1

You can do that with

roots([2 2 1])

or using your function, simply divide through by 2 and don't include the leading 1.

[rts,it]=bairstow([1 1/2],2,1e-3);

As I read Walter's post that is exactly what he clearly explained to you. And I certainly tried to explain very much the same thing.

It seems to me that you're much better off learning to provide the correct input to the funtion you have instead of trying to modify it to accept the input you want to give it.

[Walter Roberson]

Yup, exactly.

if a(1) ~= 1; a = a ./ a(1); end

a = a(2:end);

The test for 1 is merely an optimization. You could just use

a = a(2:end) ./ a(1);