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 The information provided may be out of date.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.

mathematical expression

Please login with a confirmed email address before reporting spam

Hi people
in the expressions in general I have terms to which I can assign a value or even an expression.
In the maths module I have a source term "f"
I can assign to f any value I want

but how can I assign to f the derivative of u?
I mean, to have f=du/dx what should I write in there?

should I write ux? dux? u'x ?




1 Reply Last Post 05.09.2012, 16:07 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 05.09.2012, 16:07 GMT-4
Hi

if u is a deendent variable of your PDE then COMSOL notation makes ux the first derivative of u along x, uxx the second derivative etc ... See the doc it's all in there use the search

--
Good luck
Ivar
Hi if u is a deendent variable of your PDE then COMSOL notation makes ux the first derivative of u along x, uxx the second derivative etc ... See the doc it's all in there use the search -- Good luck Ivar

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.