Optimal 25-Point Finite-Difference Subgridding Techniques for the 2D Helmholtz Equation

Table 1

The performance of the refined uniform 25p. The pair denotes the error for the layer with and the layer with , respectively.

	12 m	6 m	3 m	1.5 m
	8281	25921	68121	231361
Errors	(0.2915, 0.0888)	(0.0282, 0.0119)	(0.0205, 0.0075)	(0.0185, 0.0025)
Time	s	s	s	s