Different Versions of ILU and IUL Factorizations Obtained from Forward and Backward Factored Approximate Inverse Processes—Part I

Table 2

properties of ILUFF1, ILUFF2, ILUFF3, and ILUFF4 preconditioners.

Method	ILUFF1		ILUFF2		ILUFF3		ILUFF4
	Density	𝑃time	Density	𝑃time	Density	𝑃time	Density	𝑃time
hor-131	0.984696	22.031	1.098996	43.86	0.990435	32.422	1.075562	32.64
sherman2	0.463237	466.531	0.682342	742.432	0.462847	637.203	0.687668	666.312
cavity05	0.272646	736.343	0.338992	1567.223	0.280553	1079.63	0.368013	1139.59
cavity06	0.291794	678.782	0.376243	1484.22	0.295636	993	0.407515	817.828
sherman4	1.243001	266.203	1.312467	804.922	1.243001	319.172	1.321447	574.328
epb0	1.575348	943.093	1.981968	2360.44	1.750386	1274.88	2.248583	1777.27
pde2961	1.234763	6996.83	1.327048	10863	1.248269	5879.3	1.334248	9262.47