SciPy's eigh - How to Lose an Afternoon

So the SciPy package for Python is full of lots of goodness.  Be very careful using the eigh() routine to get eigenvalues, though.  There's a "gotcha" buried in it.

The syntax is:

(eigenvalues, eigenvectors) = eigh(matrix)

This returns an array of eigenvalues and a 2D array of eigenvectors (each eigenvector consists of many components).

And there's the gotcha.  Let's say you want the nth eigenvalue and eigenvector.  I would write:

eigenvalues[n]
eigenvectors[n]

And I would be horribly wrong.  The eigenvectors and eigenvalues do share an index, but the index on the eigenvector is SECOND column:

eigenvectors[:,n]

Seriously WTF.

Update: It turns out that this is due to eigh() being part of LAPACK, which is a non-Python library (Fortran?) that has a different internal storage model for 2D arrays.  So possibly less WTF, but still dangerous as all hell.