HTRIB3(3F)

NAME
     HTRIB3, SHTRIB3  -  EISPACK routine.  This subroutine forms the
     eigenvectors of a COMPLEX HERMITIAN matrix by back transforming those of
     the corresponding real symmetric tridiagonal matrix determined by
     HTRID3.


SYNOPSYS
          subroutine  htrib3(nm, n, a, tau, m, zr, zi)
          integer          nm, n, m
          double precision a(nm,n), tau(2,n), zr(nm,m), zi(nm,m)

          subroutine shtrib3(nm, n, a, tau, m, zr, zi)
          integer          nm, n, m
          real             a(nm,n), tau(2,n), zr(nm,m), zi(nm,m)



DESCRIPTION
     On INPUT

     NM must be set to the row dimension of two-dimensional array parameters
     as declared in the calling program dimension statement.

     N is the order of the matrix.

     A contains information about the unitary transformations used in the
     reduction by  HTRID3.

     TAU contains further information about the transformations.

     M IS the number of eigenvectors to be back transformed.

     ZR contains the eigenvectors to be back transformed in its first M
     columns.  On OUTPUT

     ZR and ZI contain the real and imaginary parts, respectively, of the
     transformed eigenvectors in their first M columns.  NOTE that the last
     component of each returned vector is real and that vector Euclidean norms
     are preserved.  Questions and comments should be directed to B. S.
     Garbow, APPLIED MATHEMATICS DIVISION, ARGONNE NATIONAL LABORATORY