wdk-axial grid accuracy tests

output.txt

Impulse parameters:
    Sr: ~5
    St: ~5
    Initial step: 1e-3

Simple:
00100    0.010000    1.000000    0.499973642552    0.500000000000    1.000032834871
Error: 0.000052715 (reference)

With 1 buffer step:
00100    0.010000    1.000000    0.499979048654    0.500000000000    1.000032247424
Error: 0.000041903 (−20.51%)

With 2 buffer steps:
00100    0.010000    1.000000    0.499983009604    0.500000000000    1.000031676817
Error: 0.000033981 (−35.54%)

With unlimited annulus and 1 buffer step:
00100    0.010000    1.000000    0.500003166034    0.500000000000    1.000035652764
Error: 0.000006332 (-87.99%)

With unlimited annulus and 2 buffer steps:
00100    0.010000    1.000000    0.499997335576    0.500000000000    1.000034674039
Error: 0.000005329 (−89.89%)