IK - report_marker_locations

[Nils Kästner]

Hallo everybody,

for e better scaling result I would like to compare the experimental marker data with the virtual marker data. The IK-Tool produces a file with the virtual marker positions and it displays some mean errors. I want to look at the error for one spezific marker (not necessary the marker with maximum error).

My first question: Is it possible, that the IK-Tool saves the difference between the virtual and experimentel markers? I didn't find such an option.

Since I could not find this option in the Tool, I tried to calculate the errors by myself. The problem is, that in the "virtual marker positions"-data some markers are missing. Actually 111 marker-coordinates (that meens 37 markers) are printed. Indeed it should be 50 markers. And there is another problem. I use a simple model without arms. In my experimental "*.trc" data additional markers (for example those at the arms) are saved. Those markers are also saved in the "virtual marker positions"-file.

Perhaps somone can help me.
Thanks a lot.
Nils Kästner

[jimmy d]

Nils-

if you flag <report_marker_locations> true </report_marker_locations> in the IK setup xml it will print out all the virtual marker locations of the model. This file gets overwritten with each subsequent IK trial (that comes from the same folder)

Is this the flag you have been using?

-james

[Nils Kästner]

Hallo James,

I'm using exact this flag. But not all markers are printed in the file. For example "left ankle" marker exists but the "right ankle" marker doesn't.

The second problem is that even ther is no virtual Hand marker for example, coordinates of this marker are saved in the file.

Nils

[jimmy d]

Nils-
We have reproduced this bug. Thanks for bringing it to our attention. We are working on it now and it will be fixed for the next release.
-James

[Carlo Tricarico]

Hello to all of you,
I'm sorry, I was wondering where can I find the flag you've mentioned because I cannot see it.

Thanx a lot

Carlo

[jimmy d]

Carlo-
It would be located in the IK setup file. As it is not written in by default you would have to add it to your file.
Cheers,
-james

[Carlo Tricarico]

Thank you so much James. Everything worked

Best regards

Carlo

[Maxime Bourgain]

Do you know how to define the name of the file created with the flag ?
<report_marker_locations> true </report_marker_locations>

[Dario Cazzola]

Hi Maxime,

in your IK file you can define:

<!--Directory used for writing results.-->
<results_directory>\\Mac\Home\Desktop\Work\Research\OpenSim\Projects\HIP_FORCES\TRIALS\STST1\IK\</results_directory>

OpenSim will save the file containing the markers in that directory. The names will be something like:
ik_model_marker_locations.sto

Cheers

Dario