$\alpha$

h

Error

Convergence order

1.1

1/20

2.2758e−04

1/40

5.5737e−05

2.0297

1/80

1.4522e−05

1.9404

1/160

3.7257e−06

1.9627

1.4

1/20

5.2987e−04

1/40

1.3674e−04

1.9542

1/80

3.5695e−05

1.9376

1/160

9.1295e−06

1.9671

1.7

1/20

1.2000e−03

1/40

2.9715e−04

2.0138

1/80

7.5993e−05

1.9673

1/160

1.9249e−05

1.9811