What does roots/ eig do exactly?

1 次查看（过去 30 天）

Thomas Waljor 2015-8-5

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/232521-what-does-roots-eig-do-exactly

评论： James Tursa 2015-8-5

I want to write a programm on Matlab, without using implemented functions. This programm should be similiar to the Matlab function roots. But I am not sure what roots does, is there any possibility to read something like a pseudo-code of roots or eig? Or is it possible to find .m file that fullfills this conditions?

Is roots simply using the QR decomposition with shifts ?

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Sean de Wolski 2015-8-5

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/232521-what-does-roots-eig-do-exactly#answer_188379

编辑：Sean de Wolski 2015-8-5

在 MATLAB Online 中打开

>>edit roots

7 个评论
显示 5更早的评论隐藏 5更早的评论

Thomas Waljor 2015-8-5

For my bachelor thesis I wrote a programm that computes the roots of a polynomial quiet fast. One part of mine assignment is to compare this algorithm with the in Matlab implemented roots function. It is impossible to compare them directly, since I had to use Matlab to programm the first algorithm. Right now I try to figure out how roots computes the roots of a polynomial.

James Tursa 2015-8-5

By looking at the code for roots you have that answer. It constructs a matrix where the characteristic polynomial of that matrix is your polynomial. Then it uses eig to find eigenvalues of that matrix, which will be equal to the roots of the characteristic polynomial.

请先登录，再进行评论。