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In R, the eigen() returns descending sorted eigenvalues. However, the eigenvectors do not correspond to these sorted eigenvalues. How do I identify the eigenvector corresponding to the ith sorted eigenvalue?

One approach might be to sort by the norm of the eigenvectors (is there a procedure in R that can do this). I imagine there is a simple method I am missing.

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    $\begingroup$ "However, the eigenvectors do not correspond to these sorted eigenvalues" yes it does. "One approach might be to sort by the norm of the eigenvectors" hard, given that eigenvectors are normed $\endgroup$ – user603 Aug 23 '11 at 6:34
  • $\begingroup$ The following webpage suggested the vectors from eigen() were not sorted: tolstoy.newcastle.edu.au/R/help/03a/3713.html $\endgroup$ – Ram Ahluwalia Aug 23 '11 at 13:52
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Look at the end of the eigen function:

...    
ord <- sort.list(Mod(z$values), decreasing = TRUE)
}
list(values = z$values[ord], vectors = if (!only.values) z$vectors[, 
      ord, drop = FALSE])}

That means both values and vectors are sorted by ord. So why eigenvectors ordering is not corresponding to the eigenvalues ordering?

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    $\begingroup$ It is also crucial to me since I use this for the extraction of static factors. $\endgroup$ – Dmitrij Celov Aug 23 '11 at 7:45

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