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.

Undefined variable problem

Please login with a confirmed email address before reporting spam

Trying to do a 3d frequency domain simulation, but it keeps showing this error message:

Undefined variable. - Variable: comp1.tEx_lm - Geometry: geom1 - Boundaries: 2, 31 Failed to evaluate Jacobian of expression. - Expression: -comp1.tEx_lm Failed to evaluate Jacobian of expression. - Expression: ((comp1.tEx-comp1.ewfd.PortConstrx)test(-comp1.tEx_lm))(dvol_spatial)

I think tEx_lm is Lagrange multiplier for electric field, though I have no idea how to fix it.


1 Reply Last Post 2021年5月7日 GMT+8 08:30
Robert Koslover Certified Consultant

Please login with a confirmed email address before reporting spam

Posted: 3 years ago 2021年5月7日 GMT+8 08:30

Although I am not familiar with that particular variable, my best guess is you have some kind of mistake in the way you set up your model. There are so many, many possible ways to make mistakes when creating a Comsol model. I suggest you post your model to the forum, so others can check it out. One of us just might find the error.

-------------------
Scientific Applications & Research Associates (SARA) Inc.
www.comsol.com/partners-consultants/certified-consultants/sara
Although I am not familiar with that particular variable, my best guess is you have some kind of mistake in the way you set up your model. There are so many, many possible ways to make mistakes when creating a Comsol model. I suggest you post your model to the forum, so others can check it out. One of us just might find the error.

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.