Richardson Cascadic Multigrid Method for 2D Poisson Equation Based on a Fourth Order Compact Scheme

Table 1

Numerical results of EXCMG and RCMG for Example 4.

𝐿	1/ℎ𝐿	EXCMG		RCMG
		||𝑢^𝐿−𝑢||∞	cpu	||𝑢^𝐿−𝑢||∞	cpu
3	128	6.28𝐸−07	0.37	1.27𝐸−07	0.14
	256	1.12𝐸−07	1.12	1.85𝐸−08	0.31
	512	1.07𝐸−08	4.10	2.58𝐸−09	1.12
4	128	4.76𝐸−07	0.34	2.61𝐸−07	0.08
	256	1.27𝐸−07	1.19	6.11𝐸−08	0.42
	512	3.58𝐸−08	4.38	6.07𝐸−09	1.29
5	128	9.21𝐸−07	0.51	3.05𝐸−07	0.08
	256	1.62𝐸−07	1.06	7.82𝐸−08	0.31
	512	2.72𝐸−08	4.15	1.72𝐸−08	1.15