N | Midpoint error | rate | Richardson’s extrap. | rate |
8 | 0.007024577280901 | −0.00011693442490234 | ||
16 | 0.0017507392430902 | 4.01234 | −7.20676951360e−06 | 16.22563 |
32 | 0.0004373481675656 | 4.00307 | −4.4885760908108e−07 | 16.05580 |
64 | 0.00010931601997121 | 4.00076 | −2.80292269394e−08 | 16.01391 |
128 | 2.7327691408896e-05 | 4.00019 | −1.7514452110845e−09 | 16.00348 |