Subject: [FFC-dev] [DOLFIN-dev] Higher-order problems?

From: Nuno David Lopes <[email-masked]>
Date: Thu, 25 Jun 2009 11:26:50 +0100

Hi!

Is there any demo/sandbox  with a problem involving higher-order derivatives? 

I'm trying to solve some 4th order equations but  with  no successful 
solutions until know. (This is, 2nd and/or 3th order derivatives in the 
variational forms.)

What should be the syntax for the higher order derivatives in the ufl file?   
I'm using div grad compositions, for instance, div(grad(u)) for the laplacian 
of u. Everything compiles fine, 

Thanks.

-- 
Nuno David Lopes

e-mail:[email-masked]        (FCUL/CMAF)
           [email-masked]    (ISEL)
http://ptmat.ptmat.fc.ul.pt/%7Endl/ 

Thu Jun 25 10:49:51 WEST 2009

---

From: Anders Logg <[email-masked]>
Date: Thu, 25 Jun 2009 18:56:35 +0200

> of u. Everything compiles fine, 

This should work, but I don't know of a demo testing it.

See if you could create a very simple test case that fails.

-- 
Anders