[Numpy-discussion] linalg.eigh orders eigenvalues/eigenvectors
differently than linalg.eig  Zachary Pincus zpincus@stanford....
Mon Feb 19 04:56:34 CST 2007  Hello all,  It seems that the
'eigh' routine from numpy.linalg does not follow   the same
convention as numpy.linalg.eig in terms of the order of the
returned eigenvalues. (And thus eigenvectors as well...)
Specifically, eig returns eigenvalues in order from largest to
smallest, while eigh returns them from smallest to largest.
>>> a = numpy.array([[21, 28, 35],[28, 38, 48],[35, 48, 61]])
>>> numpy.linalg.eigh(a) (array([ -1.02825542e-14,
7.04131679e-01,   1.19295868e+02]), array([[ 0.40824829,
-0.81314396, -0.41488581],         [-0.81649658, -0.12200588,
-0.56431188],         [ 0.40824829,  0.56913221, -0.71373795]]))
>>> numpy.linalg.eig(a) (array([  1.19295868e+02,
7.04131679e-01,   4.62814557e-15]), array([[-0.41488581,
-0.81314396,  0.40824829],         [-0.56431188, -0.12200588,
-0.81649658],         [-0.71373795,  0.56913221,  0.4082