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.

sweep + Values of variables not solved for

Please login with a confirmed email address before reporting spam

I have a model which consists of two studies:
- Study 1 : Stationary with parametric sweep of parameter A
- Study 2 : Eigenmode, with parametric sweep of A, the result of Study 1 is the input for Study 2.

I was amusing that by using "Values of variables not solved for" I would get it work, but when I run a sweep of A I get always the same result for Step 2. I tried setting "Parameter value (A)" to "All" or "Automatic" but it seems that in both cases only the results of the last value of A from Step 1 is considered. If I set "Parameter value (A)" to a specific value and run the simulation for that value it works. My question is how I can access the results from Step 1 in a sweep?
Please advise.

Thanks
Mohsen

5 Replies Last Post 29 ago 2016, 19:42 GMT-4
COMSOL Moderator

Hello Mohsen Sazegar

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.


Please login with a confirmed email address before reporting spam

Posted: 9 years ago 18 giu 2015, 16:51 GMT-4
Has this problem been resolved? I've come across the same problem in 5.1, where my second study uses the results of my first study as the value for the dependent variable not solved for. My first study is a stationary parametric sweep that calculates the electric fields for given values of potential differences between parts of the geometry, and the second study is a time dependent study that computes the trajectories of particles in the fields from study 1. Even if the parameter value to be used in the "Values of variables not solved for" section is set to "all", only the last parameter value is accessible in the particle trajectory plot. Does anyone have a solution to this?
Has this problem been resolved? I've come across the same problem in 5.1, where my second study uses the results of my first study as the value for the dependent variable not solved for. My first study is a stationary parametric sweep that calculates the electric fields for given values of potential differences between parts of the geometry, and the second study is a time dependent study that computes the trajectories of particles in the fields from study 1. Even if the parameter value to be used in the "Values of variables not solved for" section is set to "all", only the last parameter value is accessible in the particle trajectory plot. Does anyone have a solution to this?

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 4 ago 2015, 21:19 GMT-4
Hi Alexander, did you figure this out? I'm using 5.0 and have the same annoying problem
Hi Alexander, did you figure this out? I'm using 5.0 and have the same annoying problem

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 4 ago 2015, 21:43 GMT-4
Hi Arjun,

I did not ever figure this out. I end up manually creating each model file with the attributes that the sweeps would have covered, but this was mostly due to my workstation not being able to handle the memory required for even one of the sweeps. Instead of doing a file for each combination of parameters, you could just do one file for each parameter value in the first study, and then doing the parametric sweep as normal in the second study. You may also be able to combine both steps into one study and doing a parametric sweep over two parameters in that one study.

Good luck
Hi Arjun, I did not ever figure this out. I end up manually creating each model file with the attributes that the sweeps would have covered, but this was mostly due to my workstation not being able to handle the memory required for even one of the sweeps. Instead of doing a file for each combination of parameters, you could just do one file for each parameter value in the first study, and then doing the parametric sweep as normal in the second study. You may also be able to combine both steps into one study and doing a parametric sweep over two parameters in that one study. Good luck

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 4 ago 2015, 22:59 GMT-4
Yeah, I have way too many parameters to do it individually. I'm running it on a cluster.

Anyway, thanks for your time.

Cheers.
Yeah, I have way too many parameters to do it individually. I'm running it on a cluster. Anyway, thanks for your time. Cheers.

Peter Norgaard COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 8 years ago 29 ago 2016, 19:42 GMT-4
I believe it works to use either the "Interpolated" or "Manual" settings for parameter value in the Values of Dependent Variables section. If it's the Interpolated setting, then the expected input is the value of the parameter from the previous study. If you are iterating over the same parameter in your study 2 parametric sweep, then put that parameter name in here. Alternately, with the Manual setting, you need to run over the whole numbers that index your previous parameter study (1, 2, 3, ... ).
I believe it works to use either the "Interpolated" or "Manual" settings for parameter value in the Values of Dependent Variables section. If it's the Interpolated setting, then the expected input is the value of the parameter from the previous study. If you are iterating over the same parameter in your study 2 parametric sweep, then put that parameter name in here. Alternately, with the Manual setting, you need to run over the whole numbers that index your previous parameter study (1, 2, 3, ... ).

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.