title: Sorting eigensystem obtained from zgeev
body: <p>I'm using the Lapack routine <a href="http://www.netlib.org/lapack/complex16/zgeev.f" rel="nofollow">zgeev</a> to obtain the (complex) eigenvalues and
  eigenvectors of a non-symmetric complex matrix in Fortran. The resulting array
  of eigenvectors is in some arbitrary order. I would like to reorder both the
  array of eigenvalues and the corresponding columns in the matrix of eigenvectors
  so that the eigenvalues are in ascending order with respect to the real part of
  each eigenvalue. I could of course roll my own sorting routine, but I was
  wondering if there was already a Fortran routine somewhere that can do this for
  me, maybe even as part of lapack.</p>