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linear algebra - Sort eigenvectors of a list of matrices


I have a list of matrices and want to obtain a list of eigenvectors and eigenvalues for each matrix, both sorted by the size of the eigenvalue. If I write system={eigenvalues, eigenvectors}, where eigenvalues is a list of lists of eigenvalues for each of the matrices, I would like to sort the eigenvectors by writing


Map[Sort[#, #1[[1]] < #2[[1]]] &, Transpose[system]] 

of some sort, but this does nothing useful.



Answer






Ordering[Norm /@ Last @ N[Eigensystem[system]]];


gives you the ordering by norm. You can apply this on your eigenvalues and eigenvectors, e.g.




Eigenvectors[system][[%]]



EDIT


To apply this on a list of matrices:




(# &@Ordering[Norm /@ N[#]]) & /@ Eigenvectors[#] & /@ {mat1,mat2,...,matn}


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