About solving eigenvalue problem in MATLAB

Dear all,

I have questions regarding solving eigenvalue problem in MATLAB. I know that the command of solving eigenvalue problem is 'eig' and I would like to ask two questions about it to have more understanding about that,

1. If A is symmetric positive-definite, after running [V,D] = eig(A), the eigenvalues in D is always in ascending order across the diagonal? What other kinds of matrix will get D having eigenvalues in ascending order?

2. What kind of numerical algorithm used in 'eig' in solving eigenvalue? I guess different algorithm is used when different kind of matrix (ie. positive definite matrix) is used.

Thanks for your attention...