Differences between data in PostView

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • andrach
    Junior Member
    • Nov 2012
    • 13

    Differences between data in PostView

    Hi all,

    I'm analyzing the results of my simulation and the Effective Stress values that appear on the color bar in PostView are different from the ones that are exported using PostView-Summarize-Save. I attached one image that shows these differences.

    1) Why are these values different?

    2) How can I access the values that appear on the color bar?

    Thanks!

    AndraValues.jpg
  • maas
    Lead Code Developer
    • Nov 2007
    • 3400

    #2
    Hi Andra,

    The range for the color bar is determined by the nodal values. Since stress is exported from FEBio as an element value, PostView calculates the nodal value by taking the average of the surrounding element values. The summary view, on the other hand, displays the stats of the element values. Due to the averaging, the color bar range will also be slightly smaller than the actual element value range. However, in your case, the difference seems to be a factor of two, which seems suspiciously high. Can you please send me that plot file? If it's too big to attach, you may email to steve dot maas at utah dot edu.

    To answer your question, to see the values from the color bar, select the nodes you are interested in and open the TrackView window.

    Cheers,

    Steve
    Department of Bioengineering, University of Utah
    Scientific Computing and Imaging institute, University of Utah

    Comment

    • andrach
      Junior Member
      • Nov 2012
      • 13

      #3
      Hi Steve!

      Thanks for your answer. I sent you an email with the model.

      Regards,
      Andra

      Comment

      • kostas
        Junior Member
        • Jul 2020
        • 13

        #4
        Hi Steve,

        I also seem to have this problem. The results that appear in the color bar in PostView have a significant difference from those in the Summary view, as you can see in the screenshot below. Do you have any suggestions ? Thank you in advance!

        Screenshot_4.png

        Comment

        • maas
          Lead Code Developer
          • Nov 2007
          • 3400

          #5
          The data range in the color bar is taken from the nodal values. However, if the data field you are looking at is not a nodal field (e.g. stress), then the nodal values are interpolated from the element data. The Summary View, on the other hand, will not do any interpolation and use the actual data (so, an element field will only look at element values). So, in general, the ranges listed in the Summary view will be more accurate.
          Usually, the differences should be relatively small, and when they are not, this might be an indication that the mesh is too coarse and the solution is not converged.
          If you suspect that this does not explain what you are seeing, please send me the model and I'd be happy to take a closer look.

          Cheers,

          Steve
          Department of Bioengineering, University of Utah
          Scientific Computing and Imaging institute, University of Utah

          Comment

          • kostas
            Junior Member
            • Jul 2020
            • 13

            #6
            Hi Steve,

            It would really help actually if you could take a closer look. The mesh I am using is adequately fine but the data still have a relatively big difference. Is there something that I could try in the Step settings in order to resolve this ?
            What also made an impression on me is that I am using "isotropic elasticity" as the material and the elapsed time was around 8 minutes but when I was using the "fung orthotropic" material (with the exact same settings) the elapsed time was 8 hours. Could this be caused by the difference in the designated materials? Thank you in advance!

            Kostas

            Comment

            • maas
              Lead Code Developer
              • Nov 2007
              • 3400

              #7
              Hi Kostas,

              It looks like the link expired. Can you please send me a new link or email me the file directly?

              Thanks,

              Steve
              Department of Bioengineering, University of Utah
              Scientific Computing and Imaging institute, University of Utah

              Comment

              • kostas
                Junior Member
                • Jul 2020
                • 13

                #8
                Hey Steve,
                Thanks again for taking the time.

                Comment

                • maas
                  Lead Code Developer
                  • Nov 2007
                  • 3400

                  #9
                  Hi Kostas,

                  The numbers in this file are different than the figure above, and they do seem to agree, so maybe double-check if you send me the right file. Also, try this:
                  - On the Post\View panel, under the "Color Map" options, set Nodal Smoothing to "No". This will evaluate the raw element data, without smoothing. For the file you sent me, the resulting scale bar range and the numbers in the Summary panel nearly agree. Please give that a try and let me know what you find.

                  Cheers,

                  Steve
                  Department of Bioengineering, University of Utah
                  Scientific Computing and Imaging institute, University of Utah

                  Comment

                  Working...
                  X
                  😀
                  😂
                  🥰
                  😘
                  🤢
                  😎
                  😞
                  😡
                  👍
                  👎