Matrix Error when trying to do x = A\0

Question

jake stan 2018-3-1

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/385612-matrix-error-when-trying-to-do-x-a-0

评论： jake stan 2018-3-2

采纳的回答： Steven Lord

I get this error:

Warning: Matrix is close to singular or badly scaled. Results may be inaccurate. RCOND = 6.864902e-17.

I had a 3x3 matrix then calculated the eigen matrix by finding the eigenvalues then subbing it back in to the matrix.

I proceeded to try to solve the equation Ax = 0, where A is the eigenmatrix, and I need to find the eigenvectors.

I tried x = A\[0;0;0], but the error prompted, and I get x = 0, 0,0 which is wrong since I did [v, d] = eig(original_matrix) to check the values.

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。

Answer 1

Steven Lord 2018-3-1

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/385612-matrix-error-when-trying-to-do-x-a-0#answer_307859

The vector x = [0; 0; 0] is one solution to the system A*x = [0; 0; 0] for a 3-by-3 matrix A. It may not be the only solution to that system. In this case, the backslash operator is not the right tool for the job.

Assuming you're not allowed to use the eig function to compute the answer directly (because this is homework?) take a look at what the null function gives you. But if this is homework, good thought to use the eig function to check your work.