superconvergence about firedrake

[colinjcotter]

Probably symmetric cancellations on the structured grid (perhaps combined with symmetric solution). Try breaking some of the symmetries.

[qk11853]

Probably symmetric cancellations on the structured grid (perhaps combined with symmetric solution). Try breaking some of the symmetries.

I'm not quite sure what you mean. How can I solve it?
Thank you very much for your reply!

[colinjcotter]

There is nothing to solve? Error analysis provides an upper bound in the general case. Sometimes we are lucky.

[qk11853]

There is nothing to solve? Error analysis provides an upper bound in the general case. Sometimes we are lucky.
For the finite element, P1 polynomial space, we get second-order convergence in the L2 sense and first-order convergence in the H1 sense.
Now what I get with firedrake is second order and second order, how do I fix it?

[colinjcotter]

This is not inconsistent with the theory

[qk11853]

This is not inconsistent with the theory

But this superconvergent result, how can I get a result that's not superconvergent?

[colinjcotter]

Try a less symmetric case On 9 Jun 2024, at 10:58, qk11853 ***@***.***> wrote:  This is not inconsistent with the theory But this superconvergent result, how can I get a result that's not superconvergent? — Reply to this email directly, view it on GitHub<#3622 (comment)>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/ABOSV4R2SWHII5VV3TNEMF3ZGQRKNAVCNFSM6AAAAABJATO7ASVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDCNJWGQZDCOBTHA>. You are receiving this because you commented.Message ID: ***@***.***>