Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Improving precision of derivatives

Please login with a confirmed email address before reporting spam

Hello,

I have a pretty simple 1D simulation. I can solve it with COMSOL just fine, and the results are good, however when I take derivatives (even just the first derivative), I notice there can be quite a bit of error.

I've tried increasing mesh size, as well as using higher order geometry shapes up to quintic, unfortunately neither of these strategies seem to improve the results.

In order to rectify this, I've been taking the results generated by COMSOL, and then use those as boundary conditions in MATLABs bvp5c routine, resolve the ODE and then use the derivatives generated by MATLAB. For some reason the derivatives generated by bvp5c are good, while those generated by COMSOL aren't so good.

Any suggestions?

Thanks,
Mark

0 Replies Last Post 7 mars 2014, 17:42 UTC−5
COMSOL Moderator

Hello Mark Fleharty

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.