Sudheer Phani <bpsu <at> james.hut.fi> writes:

>
> Hello All,
>
>    I have been encountering some strange problems with the calculation of
> eigen vectors using python. The problem is with the sign of the eigen
> vectors calculated. On Very few occasions the eigen vectors calculated
> using python have an opposite sign than the actual eigenvectors, though
> the magnitude is correct.
>
> Can any one of you plz help me in this regard and suggest me some solution
> if you have encoutered similar problems .
>
> Any help in this regd is appreciated
>
> Thanks in Advace
>
> regds
> Sudheer
>


I had a similar experience.  However, I solved it when I realized that the eig
routine in scipy.linalg does not necessarily return the biggest
eigenvalue/eigenvector first.  It often does, but not always.  Once I realized I
had to find the biggest one on my own, the problem was solved.