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Saving marker errors in Opensim 3.3

Posted: Mon Mar 16, 2020 8:05 pm
by marcus_95
Hello,

I'm using Opensim 3.3 and the related API for Matlab and I would like to save the marker errors for each of my trials. I know that the API of Opensim 4.0 for Matlab automatically does this job when you run the InverseKinematicsTool (by using the run() function), saving the marker errors in a .sto file. Is there a way to do the same by using the Opensim 3.3 API for Matlab?

Thank you!

Re: Saving marker errors in Opensim 3.3

Posted: Tue Mar 17, 2020 1:42 am
by mitkof6
Hi,

You can add the following option in the inverse kinematics' .xml setup file:

Code: Select all

<!--Flag (true or false) indicating whether or not to report marker errors from the inverse kinematics solution.-->
    <report_errors>true</report_errors>

Re: Saving marker errors in Opensim 3.3

Posted: Wed Mar 18, 2020 4:40 am
by marcus_95
Thank you! Actually these lines were already written in my .xml file but the problem was that in my case the Opensim 3.3 Api saved the marker error in a single file out.log.

I have another question: how can I get the position in ground of a body in Opensim 3.3 with Matlab? Because with the 4.0 version I can use getPositionInGround() but I didn't find this function in the earlier version.

Thank you!

Bye

Re: Saving marker errors in Opensim 3.3

Posted: Thu Mar 19, 2020 1:21 am
by mitkof6
In OpenSim v3.3 you can use the utilities within the SimbodyEngine

https://simtk.org/api_docs/opensim/api_ ... 3a00633540

Code: Select all

model.getSimbodyEngine().transform(...)

Re: Saving marker errors in Opensim 3.3

Posted: Fri Mar 20, 2020 11:37 am
by marcus_95
Thank you for the useful information! I found a solution by using the SimbodyEngine.

Best,

Marco