Active/Passive Force

[Kathleen Reilly]

The plotter in OpenSim can separately plot active and passive forces; however, I do not see these separated out in the CMC output files. I assume the _Actuation_Force.sto file contains total force. How can I obtain these separated active/passive force values (to plot in another tool)?

Thanks

[Daniel Leib]

The easiest way is to plot them using the OpenSim plot tool and then export the data to a text file. Once the data is plotted, right click on the graph and there should be an export option.

Best,

Dan

[Kathleen Reilly]

Thanks for the response!

Along those lines...
When I plot i.e. Total Force vs. Ankle Angle in the OpenSim plotter, I get a nice smooth curve.

When I plot this data elsewhere(i.e. Matlab), I get something very jagged. (Plotting something from the _Actuation_Force.sto file vs. Ankle Angle).

I was wondering what kind of smoothing or filtering OpenSim is using to get this smooth curve.

[Ayman Habib]

Kathleen,

We do not do any smoothing.

What are you plotting against? if it's against row numbers in the file or indices in excel then it will be jagged because the sampling is not necessary uniform.

-Ayman

[Kathleen Reilly]

When you export, the data you are receiving is active/passive fiber force, not actuator force, is that correct? Is there a way to get the active/passive components of the actuator force?