Table 1 Bounds of nonzero real eigenvalues of the preconditioned matrix \(\pmb{\mathcal{P}_{SS}^{-1}\mathcal{A}}\) for Example 3.1
From: Eigenvalue bounds of the shift-splitting preconditioned singular nonsymmetric saddle-point matrices
( α , β ) | The estimated bound | The exact bound |
|---|---|---|
(1.9683, 6.6748) | [3.4169e−4, 0.9993] | [0.0536, 0.9991] |
(7.8732, 6.6572) | [3.4172e−4, 0.9970] | [0.0541, 0.9966] |
(13.7782, 6.6397) | [3.4174e−4, 0.9948] | [0.0545, 0.9940] |
(19.6831, 6.6223) | [3.4176e−4, 0.9926] | [0.0550, 0.9915] |