Table 3: Order of convergence in -norm for mixed Neumann-Dirichlet BC.

Refinements Number of nodesDiameterError in -normConvergence rate

01770.3024560.236791
16630.1512280.1158091.03
225650.0756140.0541951.09
3100890.0378070.0262331.05
4400170.0189030.0129861.01
51593930.0094510.0064751.00