α

h

${\Vert u-U\Vert }_{\infty }$

Order ≈

$\Vert u-U\Vert$

Order ≈

0.3

0.6

0.9

1/20

1/30

1/40

1/50

1/20

1/30

1/40

1/50

1/20

1/30

1/40

1/50

7.7704e−07

1.5497e−07

4.9198e−08

2.0183e−08

5.9755e−06

1.1819e−06

3.7415e−07

1.5328e−07

9.8734e−06

1.9511e−06

6.1742e−07

2.5291e−07

—

3.9763

3.9884

3.9930

—

3.9968

3.9982

3.9992

—

3.9990

3.9996

3.9997

3.8685e−07

7.7155e−08

2.4494e−08

1.0048e−08

2.9861e−06

5.9065e−07

1.8697e−07

7.6599e−08

4.9352e−06

9.7526e−07

3.0862e−07

1.2641e−07

—

3.9762

3.9884

3.9932

—

3.9966

3.9984

3.9991

—

3.9990

3.9995

4.0000