[s,d]seigt  

Subroutine [s,d]seigt  calls the ARPACK subroutine [s,d]stqrb  that computes the eigenvalues and last components of the corresponding eigenvectors of the real symmetric tridiagonal matrix. This is a modification of the LAPACK subroutine [s,d]stqr . [s,d]seigt performs the task equivalent to [s,d]neigh but takes advantage of symmetry.