next up previous contents index
Next: LA_SYGVX / LA_HEGVX Up: Examples Previous: Example 1 (from Program   Contents   Index

Example 2 (from Program LA_SYGV_EXAMPLE)

Matrices $A$ and $B$ as in Example 1.

Arrays ${\bf A}$ and ${\bf B}$ on entry:

\begin{displaymath}
\begin{array}{cc} {\bf A} \\
\begin{array}{\vert rrrrr\ve...
...& * \\
-1 & 1 & -2 & 3 & 3 \\
\hline \end{array} \end{array}\end{displaymath}

Elements marked * are not used by the routine.

The call:
CALL LA_SYGV( A, B, W,
2, 'V', 'L', INFO )

A, B, INFO and W on exit:

\begin{displaymath}\begin{array}{c} {\bf A} \\
\begin{array}{\vert l@{\hspace{...
...;\; 3.95988 \times 10^{-2} \\
\hline \end{array} \end{array} \end{displaymath}


\begin{displaymath}\begin{array}{c} {\bf B} \\ \begin{array}{\vert lllll\vert} \...
...s 10^{-1} & \;\;\; 1.32047 \\
\hline \end{array} \end{array} \end{displaymath}


\begin{displaymath}\begin{array}{c} {\bf INFO} = 0 \end{array} \end{displaymath}


\begin{displaymath}\begin{array}{c} {\bf W} \\ \begin{array}{\vert l\vert} \hlin...
...8.7262 \\ \;\;\; 159.168 \\
\end{array} \right). \end{array} \end{displaymath}

The eigenvectors are:

\begin{displaymath}
\left( \begin{array}{l@{\hspace{1mm}}l@{\hspace{1mm}}l@{\hs...
...{-1} & \;\;\; 3.95988 \times 10^{-2} \\
\end{array} \right).
\end{displaymath}

The triangular factor $L$ of the Cholesky factorization of $B$ is:

\begin{displaymath}
L= \left(
\begin{array}{l@{\hspace{1mm}}l@{\hspace{1mm}}l@{\...
...80227 \times 10^{-1} & \;\;\; 1.32047 \\
\end{array} \right).
\end{displaymath}



Susan Blackford 2001-08-19