Numerical Method for Solving Matrix Coefficient Elliptic Equation on Irregular Domains with Sharp-Edged Boundaries

Table 1

Numerical error of the problem with “star” shape.

𝑛𝑥×𝑛𝑦	Error in 𝑢^−	Order
20 × 20	0.51
40 × 40	0.20	1.32
80 × 80	0.061	1.73
160 × 160	0.016	1.90
320 × 320	0.0042	1.96