**LA_SPEV** and **LA_SPEVD** compute all eigenvalues and, optionally,
all eigenvectors of a real symmetric matrix in packed storage.

**LA_HPEV** and **LA_HPEVD** compute all eigenvalues and, optionally,
all eigenvectors of a complex Hermitian matrix in packed storage.

**LA_SPEVD** and **LA_HPEVD** use a divide and conquer algorithm.
If eigenvectors are desired, they can be much faster than **LA_SPEV**
and **LA_HPEV** for large matrices but use more workspace.

Susan Blackford 2001-08-19