Menu

Discussion Forum

New Discussion
Filter

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 The information provided may be out of date.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.

sensitivity analysis: specifying the attribute of sensitivity solver

Posted Oct 21, 2010, 4:02 a.m. EDT Version 4.2 2 Replies

Mohammad Chowdhury
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Dear all

I want to do sensitivity analysis of a time dependent problem in Comsol 4.0. I want to perform forward sensitivity analysis to evaluate the gradient of the state variable w.r.t global control variable i.e. parameter. But I can not specify the attribute of the sensitivity solver such as forward or adjoint sensitivity.

I have searched the documents. Those suggests that I can change the attribute of the sensitivity physics in its' settings window or in the solver options. However I have never seen any option in both places to do that.

Can somebody suggest me about the problem? I will be grateful.

Best Regards

Mahfuz
2 Replies Last Post Dec 27, 2011, 12:39 a.m. EST
COMSOL Moderator

Hello Mohammad Chowdhury

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.

Sangamesh Deepak
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Sep 24, 2011, 4:04 p.m. EDT
Here is how I could specify the sensitivity method.

In my problem, I use stationary solver. First, I added sensitivity as an additional physics to my model. After specifying objective function and control variables, I computed solution. Once a solution is computed, a relevant tree appears below solver configurations (Study 1 -> Solver Configurations). Down the tree, a right click on stationary solver 1 (Study -> Solver Configurations -> Solver 1 -> Stationary Solver 1) allows me to add sensitivity node to stationary solver 1. In this sensitivity node, the sensitivity method can be set as either forward or adjoint. An image file showing the tree is attached.

I guess, one can similarly set sensitivity method for transient solvers too.

Initially. I too was clueless on specifying sensitivity method. As a last resort, I made a small model in COMSOL 3.5a. Examination of this COMSOL 3.5a model in COMSOL 4.2 gave me the necessary clue.
Here is how I could specify the sensitivity method. In my problem, I use stationary solver. First, I added sensitivity as an additional physics to my model. After specifying objective function and control variables, I computed solution. Once a solution is computed, a relevant tree appears below solver configurations (Study 1 -> Solver Configurations). Down the tree, a right click on stationary solver 1 (Study -> Solver Configurations -> Solver 1 -> Stationary Solver 1) allows me to add sensitivity node to stationary solver 1. In this sensitivity node, the sensitivity method can be set as either forward or adjoint. An image file showing the tree is attached. I guess, one can similarly set sensitivity method for transient solvers too. Initially. I too was clueless on specifying sensitivity method. As a last resort, I made a small model in COMSOL 3.5a. Examination of this COMSOL 3.5a model in COMSOL 4.2 gave me the necessary clue.

Attachments:

Gyeorye Lee
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago Dec 27, 2011, 12:39 a.m. EST
thanks
It's very helpful.
thanks It's very helpful.

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