h

$L^{\infty }\left(\Gamma \right)$ error

r

$L^2\left(\Gamma \right)$ error

r

1/8

1.4360E−03

-

1.4176E−03

-

1/16

3.6011E−04

2.00

3.5464E−04

2.00

1/32

9.0099E−05

2.00

8.8761E−05

2.00

1/64

2.2553E−05

2.00

2.2030E−05

2.01

1/128

5.6702E−06

1.99

5.5253E−06

2.00