Why calculations of eigenvectors of a 2 by 2 matrix with numpy crashes my Python session?
Question: I try to do the following:

    
    
    import numpy as np
    from numpy import linalg as la
    w, v = la.eig(np.array([[1, -1], [1, 1]]))
    

As a result I have a crash of the python session with the following message:

    
    
    Illegal instruction (core dumped)
    

I tried to use scipy instead of numpy. The result is the same.


Answer: I suspect that there is a problem with your installation of python/numpy/scipy
as when I try it I have no problems.

    
    
    Python 2.7.4 (default, Sep 26 2013, 03:20:26) 
    [GCC 4.7.3] on linux2
    Type "help", "copyright", "credits" or "license" for more information.
    >>> import numpy as np
    >>> from numpy import linalg as la
    >>> w, v = la.eig(np.array([[1, -1], [1, 1]]))
    >>> w
    array([ 1.+1.j,  1.-1.j])
    >>> v
    array([[ 0.70710678+0.j        ,  0.70710678+0.j        ],
           [ 0.00000000-0.70710678j,  0.00000000+0.70710678j]])
    >>> 
    

I would suggest that you try a fresh installation.

