Example 1 (from Program LA_SBEVX_EXAMPLE)

The results below are computed with $\epsilon = 1.19209 \times 10^{-7}$.
The matrix $A$ is the same as in Example 2 for LA_SBEV.

The call:
CALL LA_SBEVX( AB, W, Z=Z, VL=-4.0_wp, VU=100.0_wp, M=M, Q=Q )^7.3

${\bf W, M}$ and Q on exit:

$$\begin{array}{cc} {\bf W} \\ \begin{array}{\vert l\vert} ... ... \\ \hline \end{array} \end{array} \hspace{0.50 cm} {\bf M}=3$$

$$\begin{array}{c} {\bf Q} \\ \begin{array}{\vert rrrrr\ver... ...} & 3.19993 \times 10^{-1} \\ \hline \end{array} \end{array}$$

The eigenvalues of $A$ in the range $[-4, 100]$ are:

$$\left( \begin{array}{l} -3.71265 \\ \;\;\; 1.20058\\ \;\;\; 1.61449 \times 10^{1} \end{array} \right).$$

The unitary matrix $Q$ used in the reduction of $A$ to tridiagonal form is:

$$Q = \left( \begin{array}{rrrrr} 1 & 0~~~~~~ & 0~~~~~~ ... ...imes 10^{-1} & 3.19993 \times 10^{-1} \end{array} \right) .$$