Menu

Discussion Forum

New Discussion
Filtrer

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 The information provided may be out of date.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.

Evaluate expression for different (specific) solutions

Posted 26 août 2013, 10:58 UTC−4 Parameters, Variables, & Functions, Results & Visualization Version 4.3, Version 4.3a, Version 4.3b 3 Replies

Nikita Kondratiev
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hi all.

Does anybody know how to evaluate expression for different solutions at the same time? I mean something like coupling integral between several modes. For example I have an eigenvalue problem solved and need to integrate the multiplication of the first one and the second (fourth and sixth, or whatever).

Thanks for help if any.
3 Replies Last Post 4 oct. 2013, 10:14 UTC−4
Jeff Hiller COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 26 août 2013, 11:06 UTC−4
Hello,
The with() operator is probably what you are looking for. See the Reference Manual for details.
Best,
JF
Hello, The with() operator is probably what you are looking for. See the Reference Manual for details. Best, JF
Nikita Kondratiev
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 27 août 2013, 03:23 UTC−4
Thanks for your reply.
The advice was helpfull, but didn't solve the whole problem: operator 'with' deals with the same solution. That is it works if you have one solution (following Comsol terminology) of an equation, with several eigenvalues and you want to compute coupling integrals. But I also need to do that for different solutions. Different dependent variables different equations and different parameters.
Operator 'with' seems like taking only number of eigenvalue as an argument, not a number of solution.
Thanks for your reply. The advice was helpfull, but didn't solve the whole problem: operator 'with' deals with the same solution. That is it works if you have one solution (following Comsol terminology) of an equation, with several eigenvalues and you want to compute coupling integrals. But I also need to do that for different solutions. Different dependent variables different equations and different parameters. Operator 'with' seems like taking only number of eigenvalue as an argument, not a number of solution.
Reine Granström COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 4 oct. 2013, 10:14 UTC−4
Dear Nikita,

As stated in the documentation, the with operator can be used for time-dependent problems, parametric problems, and eigenvalue problems. We can use it to access the solution at any of the time steps, any parameter value, or any eigensolution in an expression used for plotting or data evaluation. Currently the with operator does not support inner and outer solutions, so for such models it can can not be used to access any combination of inner and outer solutions. For example, we can not use it if we have a parametric sweep (outer solution) for a time-dependent study (inner solution), or a parametric sweep (outer solution) for an eigenfrequency problem (inner solution).

Best regards,
Reine Granström
COMSOL Sweden
Dear Nikita, As stated in the documentation, the [b]with[/b] operator can be used for time-dependent problems, parametric problems, and eigenvalue problems. We can use it to access the solution at any of the time steps, any parameter value, or any eigensolution in an expression used for plotting or data evaluation. Currently the with operator does not support inner and outer solutions, so for such models it can can not be used to access any combination of inner and outer solutions. For example, we can not use it if we have a parametric sweep (outer solution) for a time-dependent study (inner solution), or a parametric sweep (outer solution) for an eigenfrequency problem (inner solution). Best regards, Reine Granström COMSOL Sweden

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.

Suggested Content