Example (from Program LA_GTSV_EXAMPLE)

The results below are computed with $\epsilon = 1.19209 \times 10^{-7}$.

$$A = \left( \begin{array}{rrrrrr} 2 & 2 \\ 1 & 5 & 4 \\ ... ...0 & 60 \\ 13 & 26 & 39 \\ 13 & 26 & 39 \end{array} \right)$$

Arrays ${\bf DL}$, ${\bf D}$, ${\bf DU}$ and ${\bf B}$ on entry:

$$\begin{array}{c} {\bf {\bf DL}} \\ \begin{array}{\vert r\... ...3 & 26 & 39 \\ 13 & 26 & 39 \\ \hline \end{array} \end{array}$$

The call:
CALL LA_GTSV( DL, D, DU, B, INFO )

${\bf DL}$, ${\bf D}$, ${\bf DU}$, ${\bf B}$ and ${\bf INFO}$ on exit:

$$\begin{array}{c} {\bf DL} \\ \begin{array}{\vert r\vert} ... ...} \hspace{0.25 cm} \begin{array}{c} {\bf INFO} = 0 \end{array}$$

Element marked $\circ$ is not used on exit.

Matrix $U$ and the solution of the system $A\,X = B$ are:

$$U = \left( \begin{array}{llllll} 2 & 2 & 0 \\ & 4 & 4 & 0 ... ... 3.00000 \\ 1.00000 & 2.00000 & 3.00000 \end{array} \right).$$