On entry: the
by
symmetric matrix
.
If , is stored in .
If , is stored in .
If , the upper triangular part of must be stored and the elements of the array below the diagonal are not referenced.
If , the lower triangular part of must be stored and the elements of the array above the diagonal are not referenced.
On exit: if
,
a contains the orthonormal eigenvectors of the matrix
.
If
then on exit the lower triangle (if
) or the upper triangle (if
) of
a, including the diagonal, is overwritten.