h

τ

l -error

order

l 2 -error

order

π 2 4

1 2 4

0.0612

-

0.0823

-

π 2 5

1 2 5

0.0329

0.8954

0.0435

0.9199

π 2 6

1 2 6

0.0169

0.9611

0.0224

0.9575

π 2 7

1 2 7

0.0086

0.9746

0.0113

0.9872

π 2 8

1 2 8

0.0043

1.0000

0.0057

0.9873