inverse kinematics only running through first frame

[Grace M]

I am trying to run inverse kinematics on the Grand challenge 4th competition data. When I set it up with the trc file it automates to analyze from time 0 to 0 seconds. When I manually input the initial and final time it outputs that the "number of workunits cannot be negative". If I run IK externally via MATLAB only the first frame is analyzed. Any ideas on what the issue is??

[Josh Baxter]

sounds like the input file isn't the appropriate format. can you post the TRC file you're trying to track?

[Grace M]

i get the error .trc is an invalid file extension to attach a file. But here is a google drive link to it https://drive.google.com/file/d/1dH50r3 ... sp=sharing

[Josh Baxter]

i'm not clear on how opensim parses a trc file but I do see that the header info in your file uses .txt rather than .trc (row 1) and that the frame data are not integers. that might be causing some problems?

[Grace M]

I tried changing the header to .trc but it didn't help. What do you mean by the frame data is not integers? I couldn't see any decimals/fractions when I open the file in excell. Thanks

[Thomas Uchida]

The file you uploaded is not formatted correctly. Please see the "Marker (.trc) Files" page in the Confluence documentation (https://simtk-confluence.stanford.edu/d ... c%29+Files). Specifically, you are missing a blank row before the first frame. You can test your file in the OpenSim GUI by selecting Preview Experimental Data... from the File menu.