diagonal elements
    0.586525    0.688870    1.986696    1.363859    0.674749
    7.178676   14.117370    1.968262   16.535004    5.000000
off-diagonal elements
   -0.030793   -0.342639    0.759800    0.150488
    0.267760    9.145319   -0.908878    1.626276   -7.745966
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