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I would like to know if there is a way to find a common set of eigenvectors for commutative matrices (via some option of Eigenvectors or other way). Both matrices  have  degenerated eigenvalues). Thank you in advance
Hello to all of you. I would like to tell you about this weird problem I'm having when opperating with matrices  in mathematica. I want to calculate the eigenssystem of a matrix which has seemingly not too high dimensions (729x729). The matrix is a...