diagonal elements
    0.586524    0.688875    1.986717    1.363831    0.674748
    7.178537   14.117509    1.968263   16.535000    5.000000
off-diagonal elements
   -0.030793   -0.342647    0.759790    0.150487
    0.267758    9.145267   -0.908888    1.626276   -7.745967
tridiagonal matrix
   0.59  -0.03   0.00   0.00   0.00   0.00   0.00   0.00   0.00   0.00
  -0.03   0.69  -0.34   0.00   0.00   0.00   0.00   0.00   0.00   0.00
   0.00  -0.34   1.99   0.76   0.00   0.00   0.00   0.00   0.00   0.00
   0.00   0.00   0.76   1.36   0.15   0.00   0.00   0.00   0.00   0.00
   0.00   0.00   0.00   0.15   0.67   0.27   0.00   0.00   0.00   0.00
   0.00   0.00   0.00   0.00   0.27   7.18   9.15   0.00   0.00   0.00
   0.00   0.00   0.00   0.00   0.00   9.15  14.12  -0.91   0.00   0.00
   0.00   0.00   0.00   0.00   0.00   0.00  -0.91   1.97   1.63   0.00
   0.00   0.00   0.00   0.00   0.00   0.00   0.00   1.63  16.53  -7.75
   0.00   0.00   0.00   0.00   0.00   0.00   0.00   0.00  -7.75   5.00