New Preconditioners with Two Variable Relaxation Parameters for the Discretized Time-Harmonic Maxwell Equations in Mixed Form

Figure 3

The eigenvalue distribution of the preconditioned matrix ℳ^{−1𝑘,𝜂,𝜀}𝒜 with 𝑘²=2, 𝜂=2.1 and 𝜂=32, respectively, and 𝑚+𝑛=961. The case 𝜂=2.1 is indicated by the solid line while the case 𝜂=32 is indicated by the dotted line.