$\tau =0.1$ ， $h=0.1$

$\tau =0.05$ ， $h=0.05$

$\tau =0.025$ ， $h=0.025$

$\Vert e^n\Vert$

${\Vert e^n\Vert }_{\infty }$

$\Vert e^n\Vert$

${\Vert e^n\Vert }_{\infty }$

$\Vert e^n\Vert$

${\Vert e^n\Vert }_{\infty }$

$t=5$

1.65956e−3

6.30406e−4

4.16159e−4

1.58763e−4

1.03978e−4

3.98898e−5

$t=10$

3.16856e−3

1.17107e−3

7.90691e−4

2.93462e−4

1.96653e−4

7.33886e−5

$t=15$

4.52032e−3

1.62506e−3

1.12429e−3

4.05990e−4

2.78519e−4

1.01163e−4

$t=20$

5.78398e−3

2.04292e−3

1.43419e−3

5.78398e−4

3.53889e−4

1.26318e−4