h

$\tau$

$E_{\infty }\left(h,\tau \right)$

$E_{\infty }\left(2h,2\tau \right)/E_{\infty }\left(h,\tau \right)$

1/10

1/10

0.003508

*

1/20

1/20

8.859737e−04

3.9592

1/40

1/40

2.219485e−04

3.9918

1/80

1/80

5.544056e−05

4.0034

1/160

1/160

1.385442e−05

4.0017

1/320

1/320

3.464567e−06

3.9989

1/640

1/640

8.660718e−07

4.0003