Superconvergence of a New Nonconforming Mixed Finite Element Scheme for Elliptic Problem

Table 3

Superclose results of 𝜓 and 𝑢.

𝑁	‖𝜓ℎ−𝐽ℎ𝜓‖0	Rate	‖𝑢ℎ−Πℎ𝑢‖ℎ	Rate
8^2	0.02493802431889	/	0.03360261961598	/
16^2	0.00619633909611	2.00885917091448	0.00820721453088	2.03360913804615
32^2	0.00154620480519	2.00268467156460	0.00203799536238	2.00974189629474
64^2	3.863629284378830𝑒−004	2.00070284735607	5.086068699851279𝑒−004	2.00252791412788
128^2	9.657883351384945𝑒−005	2.00017773032582	1.270955080172888𝑒−004	2.00063790775102
256^2	2.414396265195381𝑒−005	2.00004455935162	3.177035666820934𝑒−005	2.00015984995534