  schur
  Builtin Function



      SSyynnooppssiiss
        Schur decomposition.

      SSyynnttaaxx
        schur ( _A )

      DDeessccrriippttiioonn
        The schur function returns a list containing elements _t and _z,
        such that:



          _A _= _z _* _t _* _z_'


     If _A is real, the _t is in "Real-Schur" form. The "Real-Schur" form
     is block upper-triangular with 1-by-1 and 2-by-2 diagonal blocks;
     each 2-by-2 diagonal block has its diagonal elements equal and its
     off-diagonal elements of opposite sign. The eigenvalues of the
     2-by-2 block: [a, b; c, a] are: a +/- sqrt(b*c)

     schur uses the LAPACK subroutines DGEES, and ZGEES.







































