Search found 81 matches

by David John Saxby
Tue Jan 27, 2015 12:54 am
Forum: OpenSim
Topic: Question about API-Visualizer
Replies: 2
Views: 352

Re: Question about API-Visualizer

Hi James, Thanks for the reply. I wanted a "nice" visualizer and Matlab isn't "nice" :roll: . Also I was just generally trying to work with the visualizer to expand my OpenSim range. I found a solution though, as you pointed out a model is abstract. I used model(), then created a bunch of objects wi...
by David John Saxby
Wed Jan 07, 2015 7:54 pm
Forum: OpenSim
Topic: Question about API-Visualizer
Replies: 2
Views: 352

Question about API-Visualizer

Hi All, I want to use the API Visualizer through Matlab as a error checking tool for some spatial transforms I am performing (basically I want to see where some projected points end up to be confident I've done it correctly). From what I can tell, using the Visualizer through the API with Matlab wil...
by David John Saxby
Tue Oct 14, 2014 7:11 pm
Forum: OpenSim
Topic: OpenSim 3.2 API for Mac
Replies: 3
Views: 588

Re: OpenSim 3.2 API for Mac

Hi Guys,

I'm working with a collaborator who uses a Mac (why I'm not sure :)). Have you guys had success building from source, and then successfully calling the API via Mac Matlab?

Just curious how much effort is involved in getting this operational.


Best,

DJS
by David John Saxby
Sun Mar 09, 2014 10:20 pm
Forum: OpenSim
Topic: Ground Reaction Force Plate
Replies: 7
Views: 1243

Re: Ground Reaction Force Plate

Hi Jim, What type of human motions do you expect to capture with your plate? Running, walking, posture work, stair assent, etc... I can only speak from my experience, but Kislter and AMTI plates are the standard. Sizing, models, etc... depends on how much money you have/want to spend, and what deman...
by David John Saxby
Tue Feb 18, 2014 12:24 am
Forum: OpenSim
Topic: Scaling with Matlab
Replies: 2
Views: 605

Re: Scaling with Matlab

Hi Carlo, In the doxygen, https://simtk.org/api_docs/opensim/api_docs/classOpenSim_1_1ModelScaler.html#aa73bb6495f4c789cb2dc411b85ed4ff2 , you will find the inputs. modelScaler.processModel(states, model, pathtoSubject, mass) So you need to provide model states, the model, the path to where the subj...
by David John Saxby
Mon Dec 23, 2013 7:07 pm
Forum: OpenSim
Topic: Define the axis of rotation angles
Replies: 6
Views: 1448

Re: Define the axis of rotation angles

Hi Derya, 1) Rotation 1, 2, 3 do not define the axes of rotation, they are a semantic for the rotation and indicate the rotation sequence. The tag within <transform axis> called <axis> lists axis for which the mobility is associated. If it is rotational then rotation about this axis, if translation ...
by David John Saxby
Thu Dec 05, 2013 7:03 pm
Forum: OpenSim
Topic: Do NaN values affect Inverse Kinematics Solution?
Replies: 1
Views: 294

Re: Do NaN values affect Inverse Kinematics Solution?

Hi Shaun, I don't think this will "add" error, but a NAN for a marker will be dropped from the evaluation of IK's objective function for the frames were a NAN is present. The result will be a global solution for model general coordinates which does not include that marker(s). If that marker(s) was i...
by David John Saxby
Mon Dec 02, 2013 9:28 pm
Forum: OpenSim
Topic: Performing Inverse Dynamics via Matlab API
Replies: 30
Views: 9805

Re: Performing Inverse Dynamics via Matlab API

Hi Gunter, That is fairly weird regarding the method problem. % Apply the generic xml to the constructor idTool = InverseDynamicsTool(genericSetupForID); % instantiate, set model, time, etc... % Create an external loads object extLoadsObject = ExternalLoads(model,activeExternalForceFile); % Set the ...
by David John Saxby
Tue Nov 19, 2013 11:33 pm
Forum: OpenSim
Topic: PROBLEM STATIC OPTIMIZATION IN SIDE STEP CUTTING
Replies: 4
Views: 942

Re: PROBLEM STATIC OPTIMIZATION IN SIDE STEP CUTTING

Hi, That is the issue with increasing the muscle force by some factor (arbitrary or incremental). Have you examined whether allometric scaling of your model to fit your subject has affected the muscles normalized operating range? The approach we take is to optimize the fiber and tendon slack length ...
by David John Saxby
Fri Nov 01, 2013 2:46 pm
Forum: OpenSim
Topic: Launch Point Kinematics Tool from Matlab
Replies: 7
Views: 1988

Re: Launch Point Kinematics Tool from Matlab

Carlo, Try James' point whereby you look in the xml file for the corresponding operation (i.e Point Kinematics operation within general Analyze Tool) and took at the tags and their names. If you then look up/search the name in the doxygen you will likely find the corresponding command (get/set, etc....