From: A reduced fourth-order compact difference scheme based on a proper orthogonal decomposition technique for parabolic equations
Spatial step size
Maximum error
Convergence order
h = 0.05
0.017367
h = 0.025
0.001197
3.8588
h = 0.0125
0.000076
3.9772
h = 0.00625
4.841e − 06
3.9726