Search found 19 matches

by In Bae Chung
Mon Oct 14, 2019 11:59 pm
Forum: OpenSim
Topic: Trajectory(.trc) from .mot file
Replies: 4
Views: 329

Re: Trajectory(.trc) from .mot file

I was able to obtain trajectory of a marker using Point Kinematics. However, the numbers are very small compared to the numbers I would get from a .trc file and doesn't match at all. Does the trajectory from Point Kinematics and .trc file have a different coordinate system? I wonder if there's a ano...
by In Bae Chung
Wed Sep 25, 2019 12:24 am
Forum: OpenSim
Topic: Adding Prescribed Force to my model
Replies: 5
Views: 812

Re: Adding Prescribed Force to my model

Thank you for the tip. error.JPG The error above kept showing up, and I managed to solve it by substituting <body>../../bodyset/hand_r </body> with <socket_frame>../../bodyset/hand_r</socket_frame> Now I can find 'prescribedForce' in the Navigator tab, but can't visualize it. Again, I checked the Fo...
by In Bae Chung
Tue Sep 24, 2019 1:24 am
Forum: OpenSim
Topic: Adding Prescribed Force to my model
Replies: 5
Views: 812

Re: Adding Prescribed Force to my model

Thank you for your reply. I guess I can try using a WeldJoint as a second option in case Prescribed Force doesn't work. Currently, the model loads without error in OpenSIM, but I cannot see the force in the model's navigation tab. navigationtab.JPG I wonder if there are any examples of .osim files t...
by In Bae Chung
Mon Sep 23, 2019 10:24 pm
Forum: OpenSim
Topic: Adding Prescribed Force to my model
Replies: 5
Views: 812

Adding Prescribed Force to my model

Hi all, I have a fullbody model in OpenSIM and have a .mot file of the model raising its arm. I wanted to implement the motion with force attached to the model's hand in the -y direction so that it can be seen as the model is lifting a heavy object. I figured out that PrescribedForce can be a soluti...
by In Bae Chung
Thu Aug 22, 2019 4:31 am
Forum: OpenSim
Topic: Trajectory(.trc) from .mot file
Replies: 4
Views: 329

Re: Trajectory(.trc) from .mot file

Thank you, that would work!
by In Bae Chung
Mon Aug 19, 2019 10:17 am
Forum: OpenSim
Topic: Trajectory(.trc) from .mot file
Replies: 4
Views: 329

Trajectory(.trc) from .mot file

Hi, everyone.

I have a .mot file but not a .trc file for a certain motion. I was wondering if it's possible to obtain .trc file from .mot file, or trajectory of a certain marker from a .mot file. Any help would be really appreciated.

Best,
In Bae Chung
by In Bae Chung
Tue Jun 25, 2019 8:02 am
Forum: OpenSim
Topic: Difference between results from OpenSIM GUI and MATLAB
Replies: 1
Views: 370

Difference between results from OpenSIM GUI and MATLAB

Hi, all. I used MATLAB to get the moment arm and tendon force of the muscles as below. import org.opensim.modeling.* %% Read data activations = STOFileAdapter.read('musclenumber.sto'); % force = STOFileAdapter.read('arm26_StaticOptimization_force.sto'); motion = STOFileAdapter.read('orig.mot'); %% I...
by In Bae Chung
Tue Jun 25, 2019 7:48 am
Forum: OpenSim
Topic: Computing muscle fiber lengths using the Python API.
Replies: 12
Views: 2033

Re: Computing muscle fiber lengths using the Python API.

Thank you Thomas. I was able to run the code without error as follows for i = 0 : nt - 1 model.updCoordinateSet().get('elbow_flexion').setValue(s, deg2rad(motion.getDependentColumnAtIndex(38).get(i) )); coord = model.getCoordinateSet().get('elbow_flexion'); model.realizeDynamics(s); % Get the comput...
by In Bae Chung
Sat Jun 22, 2019 3:03 am
Forum: OpenSim
Topic: Computing muscle fiber lengths using the Python API.
Replies: 12
Views: 2033

Re: Computing muscle fiber lengths using the Python API.

Hi, Thanks for the codes you guys provided :) You can also try something else. Update the coordinates of the model arm26.updCoordinateSet().get(i).setValue(init_state, value). Then call model.realizePosition(init_state) and recompute the muscle lengths without calling equilibrateMuscles. As you said...
by In Bae Chung
Tue Jun 18, 2019 6:52 am
Forum: OpenSim
Topic: Moment arm calculation help needed
Replies: 4
Views: 910

Re: Moment arm calculation help needed

I created an empty trajectory of states and restored continuous state variable values from a .sto file by doing this: sto = osim.Storage("orig.sto") states = osim.StatesTrajectory() states = states.createFromStatesStorage(model, sto, True) but when I try to get the Moment Arm by doing muscle = model...