Author Topic: Choosing the best parameters using quoFEM  (Read 3398 times)

Rashad

  • Newbie
  • *
  • Posts: 18
    • View Profile
Choosing the best parameters using quoFEM
« on: September 14, 2021, 11:50:10 AM »
Hello everyone,
I have used quoFEM to check some of the parameters in my model to know what the best values are. I have got the response after hit "run". could you please guide me, how can I get the best parameters among the samples?

Thanks

AakashBS

  • Newbie
  • *
  • Posts: 29
    • View Profile
Re: Choosing the best parameters using quoFEM
« Reply #1 on: September 14, 2021, 09:12:02 PM »
Hello Rashad,

To find the best parameter values, you will need to make some changes to the way you defined the analysis in quoFEM:

1) In order to find the best value of the parameters of your model, you should use the 'Parameters Estimation' method category in the ‘UQ’ panel of quoFEM, under the ‘Dakota’ UQ Engine. You also need to provide data, which are target values of the output of the model. These target values could be, for example, measurements of the output quantity of interest from experiments. Then, quoFEM will find the best values of the parameters that makes the model output match the target values of the output as well as possible.

The data for parameter estimation must be provided in a text file which should satisfy the following requirements:
•Each row contains data from one experiment
•The number of data in each row must equal the sum of the length of all response quantities defined in the QoI panel
•The order of the response quantities must match in the QoI panel, the calibration data file, and results file from analyses

So, you should provide the target value of the output Node_16_Disp_1 in a text file and provide the path to this file as input to the parameter estimation method in the UQ panel. (Refer attached figure of the UQ panel)

2) The parameter estimation method uses optimization algorithms to find the best value of the parameters, given the target value of the outputs of the model. Here, ‘the best value’ means ‘that value of the input parameters which minimizes the sum of the squared error between the outputs of the model and the data’. You will need to define the lower and upper bounds on the parameter values and the initial point for the optimization algorithm in the RV panel. (Refer attached figure of the RV panel)

3) Upon completion of the analysis, the 'best parameter' values will be displayed in the RES panel. (Refer attached figure of the RES panel)

Rashad

  • Newbie
  • *
  • Posts: 18
    • View Profile
Re: Choosing the best parameters using quoFEM
« Reply #2 on: September 15, 2021, 02:59:56 PM »
Thank YOU so much for explaining everything very well, I don't have the option "calibration data file" in the UQ panel (refer to attached photo of the UQ panel).

AakashBS

  • Newbie
  • *
  • Posts: 29
    • View Profile
Re: Choosing the best parameters using quoFEM
« Reply #3 on: September 15, 2021, 03:50:57 PM »
The option to pass in calibration data is available in the latest released version of the quoFEM app. I recommend installing this new version. You will find the link to download the app on this page - https://simcenter.designsafe-ci.org/research-tools/quofem-application/

Note that the DesignSafe-CI page is currently undergoing maintenance and will be available in a few hours.

Rashad

  • Newbie
  • *
  • Posts: 18
    • View Profile
Re: Choosing the best parameters using quoFEM
« Reply #4 on: September 15, 2021, 04:13:46 PM »
Thank you AakashBS. I'm using the latest version 2.2 also, I already try to download it again, but it shows this ( temporarily unavailable due to maintenance). I will try again later.

fmk

  • Administrator
  • Full Member
  • *****
  • Posts: 171
    • View Profile
Re: Choosing the best parameters using quoFEM
« Reply #5 on: September 15, 2021, 09:08:02 PM »
DesignSafe-ci is down for maintenance as they are upgrading the machine used to store their files. Scheduled to be back up tomorrow

Rashad

  • Newbie
  • *
  • Posts: 18
    • View Profile
Re: Choosing the best parameters using quoFEM
« Reply #6 on: September 17, 2021, 09:04:23 AM »
Hello,
 My model is stack. I have been waiting so long to download quoFEM version 2.3. and I tried to download it from another site but there is no (application file) in. so,  Could you please send me version 2.3 in an archive. thanks in advance

fmk

  • Administrator
  • Full Member
  • *****
  • Posts: 171
    • View Profile
Re: Choosing the best parameters using quoFEM
« Reply #7 on: September 17, 2021, 05:18:22 PM »
Rashad,  DesignSafe is down till Monday (20 Sept 2021) now. The executables because of their size are kept there.

AakashBS

  • Newbie
  • *
  • Posts: 29
    • View Profile
Re: Choosing the best parameters using quoFEM
« Reply #8 on: September 20, 2021, 04:24:56 PM »
The DesignSafe Data Depot is back in service. You can now download the app.

Rashad

  • Newbie
  • *
  • Posts: 18
    • View Profile
Re: Choosing the best parameters using quoFEM
« Reply #9 on: September 21, 2021, 09:17:48 AM »
Thank you,
I have download quoFEM 2.3 version, I wanted to check the app before I check my model parameters. then I logged in and hit “run” for a selected example in the category, it showed me this "No dakota. err file - dakota did not run- problem with dakota setup or the applications failed with inputs provided" however, in the old version (2.2) it works well. please what's the problem is?

Rashad

  • Newbie
  • *
  • Posts: 18
    • View Profile
Re: Choosing the best parameters using quoFEM
« Reply #10 on: September 23, 2021, 07:38:09 AM »
Hello dear all,

I am estimating my model parameters to get the best parameters values. There is one target value (120 mm as displacement at point 16) of my model. I  provided the target value and it's path of the output "Node_16_Disp_1" in a text file.

1- I am wondering - in the results - why quoFEM gives me the same values that I input in the initial point values for the optimization algorithm in ‘RV’
   panel.

2- when I select an example in quoFEM menu, the variable name in ‘Qol’  panel appears automatically. in my model, I input the variable name by myself in   
   ‘Qol’ panel. is it normal or  I have a problem? if so, how can solve it?

please, see screenshot (1)


AakashBS

  • Newbie
  • *
  • Posts: 29
    • View Profile
Re: Choosing the best parameters using quoFEM
« Reply #11 on: September 23, 2021, 03:33:33 PM »
The calibration data is provided correctly (assuming the units are consistent with your problem).

1- Can you share the 'dakota.out', 'dakotaTab.out', 'dakota.err', and 'quoFEMScalarCalibrationData.cal' files in the 'tmp.SimCenter' folder under your Local Work Directory?

2- This is normal. When you load an example from the menu, the information required to populate all the panels in the quoFEM GUI is read in from a json file. You can also create json files like this by using the 'Save As' option in the 'File' menu, once you have filled all the required inputs to define the problem. Then, you can load the json file using the 'Open' option in the 'File' menu. This will automatically fill in all the fields.

AakashBS

  • Newbie
  • *
  • Posts: 29
    • View Profile
Re: Choosing the best parameters using quoFEM
« Reply #12 on: September 23, 2021, 03:37:42 PM »
Thank you,
I have download quoFEM 2.3 version, I wanted to check the app before I check my model parameters. then I logged in and hit “run” for a selected example in the category, it showed me this "No dakota. err file - dakota did not run- problem with dakota setup or the applications failed with inputs provided" however, in the old version (2.2) it works well. please what's the problem is?

A solution to this problem is available here - https://simcenter-messageboard.designsafe-ci.org/smf/index.php?topic=191.0

Rashad

  • Newbie
  • *
  • Posts: 18
    • View Profile
Re: Choosing the best parameters using quoFEM
« Reply #13 on: September 23, 2021, 04:02:41 PM »
The files in the 'tmp.SimCenter' folder under "LocalWorkDir"  shown in the screenshot (7)

Rashad

  • Newbie
  • *
  • Posts: 18
    • View Profile
Re: Choosing the best parameters using quoFEM
« Reply #14 on: September 23, 2021, 04:24:22 PM »
I got it,  the problem was due to the convergence in the model

Thank you so much
Rashad