;-----------------------------------------------------------------
; pol_eigen.pro
;
; written by Andreas Reigber
;------------------------------------------------------------------
; Fast calculation of eigenvectors and eigenvalues of a complex 3x3
; matrix using LAPACK. Used in polarimetric eigenvector 
; decompositions.
;
; Usage: pol_eigen,matrix,ew,ev
;     matrix : complex 3x3 array
;     ev     : 3x3 complex array containing the calculated 
;              eigenvectors
;     ew     : complex array containing the calculated eigenvalues
;
;------------------------------------------------------------------
; This software has been released under the terms of the GNU Public
; license. See http://www.gnu.org/copyleft/gpl.html for details.
;------------------------------------------------------------------
pro pol_eigen,cov_mat,ew,ev
	s = size(cov_mat)
   if s[0] ne 2 or s[1] ne 3 or s[2] ne 3 or s[3] ne 6 then begin
   	print,'Wrong matrix format'
      print,'Only complex 3x3 matrices allowed'
      return
   endif
   ew=complexarr(3)
	ev=complexarr(3,3)
	dummy=call_external("liblidl.so","c_eigen_all",cov_mat,3l,ew,ev)
end