title: Can numpy diagonalise a skew-symmetric matrix with real arithmetic?
body: <p>Any skew-symmetric matrix (<strong><em>A^T = -A</em></strong>) can be turned into a Hermitian matrix (<strong><em>iA</em></strong>) and diagonalised with complex numbers. But it is <a href="http://link.springer.com/article/10.1007/BF01436375" rel="noreferrer">also possible</a> to bring it into <a href="https://en.wikipedia.org/wiki/Skew-symmetric_matrix#Spectral_theory" rel="noreferrer">block-diagonal form with a special orthogonal transformation</a> and find its eigevalues using only real arithmetic. Is this implemented anywhere in numpy?</p>