Hierarchical Matrices Method and Its Application in Electromagnetic Integral Equations

Table 1

The regression index of different levels of ML-SAI and conventional SAI preconditioning.

	Regression index	Number of unknowns
		957	3,972	16,473	65,892
ℋ-Mat.	𝑐𝑟^(100)(0)	5.568	2.297	1.371	1.042
	𝑐𝑟^(100)(1)	0.1311	0.2440	0.3155	0.4237
	𝑐𝑟^(100)(2)	0.08925	0.2034	0.2523	0.2816
	𝑐𝑟^(100)(3)	1.116E-6	0.1112	0.1828	0.2165
ML-FMA	None	5.723	2.415	1.355	0.989
	SAI	0.1052	0.2237	0.2844	0.3125