'Returns the largest eigenvalue of A.
Requires that A be symmetric.'

@Atom.numpy_numeric
def numeric(self, values):

    if (not (values[0].T == values[0]).all()):
        raise ValueError('lambda_max    called    on    a    non-symmetric    matrix.')
    lo = hi = (self.args[0].size[0] - 1)
    return LA.eigvalsh(values[0], eigvals=(lo, hi))
