Ondrej Certik wrote:

On Fri, Aug 1, 2008 at 9:26 PM, rpmu...@gmail.com <rpmu...@gmail.com> wrote:

Thanks for the reply, Robert.

The reason I think that I'm doing something wrong is that I worked out all of my integrals in terms of the element functions themselves, whereas most of the papers I've read (for example, ) work out the integrals in terms of shape functions on [0,1], typically using Gaussian quadrature, and then assemble the matrix elements over the finite elements.

Yes. It's the same thing though. Very brief explanation is in the draft of my master thesis I sent you. Instead of calculating the integral of basis functions directly, you first convert it to an integral over a reference element (introducing the Jacobian in there) and then to a sum over gauss points. This can be then easily automated.

Ondrej

Correct. Look also for 'isoparametric elements' on google: -> http://www.mathsoft.cse.clrc.ac.uk/felib/Docs/html/Intro/intro-node31.html ...

r.