Re: [R] Help with eigenvectors

From: Ben Bolker <>
Date: Tue, 08 Jul 2008 12:31:26 +0000 (UTC)

Francisco Javier Santos Alamillos <fsantos <at>> writes:

> Hi everybody,
> I have some problems with the function eigen. I have a square matrix and I
> want to calculate the eigenvalues and eigenvectors. I apply the function
> eigen and I get it, however when I solve the same problem in Statistica
> software, I realise that some eigenvectors are the opposite. How can I get
> the same values?
> Thanks in advance

  Multiply by -1 :-)
  Seriously, though, the eigenvectors can be multiplied by any constant (if L.M = aL, then (cL).M = a(cL)). (They are usually scaled to have norm 1, i.e. L.L=1.) If you are trying to match something from a previous problem, you can check the sign of one particular variable and adjust the eigenvector appropriately.

  Ben Bolker mailing list PLEASE do read the posting guide and provide commented, minimal, self-contained, reproducible code. Received on Tue 08 Jul 2008 - 12:35:13 GMT

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