Search found 31 matches

by Benjamin Michaud
Mon Feb 12, 2024 7:07 am
Forum: OpenSim
Topic: C3DFileAdapter() Reading Problem: OpenSim 4.4 vs 4.5
Replies: 2
Views: 594

Re: C3DFileAdapter() Reading Problem: OpenSim 4.4 vs 4.5

Hi everyone, Just let you know that I opened a pull request the latest version of ezc3d to OpenSim, which should fix the current problem. That said, if you are compiling OpenSim yourself, you can simply change the CMakeLists.txt file in the dependencies folder and bump the ezc3d version to 1.5.8. Re...
by Benjamin Michaud
Wed Jun 02, 2021 2:47 am
Forum: OpenSim
Topic: Troubles with Matlab (2019b or 2020b) Scripting Environment - Java error
Replies: 7
Views: 841

Re: Troubles with Matlab (2019b or 2020b) Scripting Environment - Java error

Dear all, As requested by Ayman, I've tried to open the file directly using the C3DFileAdapter using ezc3d and the file is properly loaded. As expected, it creates an empty table for the analogs when none are found, which is similar to the behavior of the previous backend (BTK). Therefore, I do not ...
by Benjamin Michaud
Tue Apr 13, 2021 4:31 pm
Forum: OpenSim
Topic: OpenSim 4.2: Matlab crash when reading C3D
Replies: 5
Views: 794

Re: OpenSim 4.2: Matlab crash when reading C3D

Hi Ton! First, I am pleased to see this amazing improvement in loading time. The small C3D files are not long enough to load so I never had the chance to really see the difference with BTK :) I do not want to pollute the OpenSim forum, but I can still answer your question (because it is a short answ...
by Benjamin Michaud
Mon Apr 12, 2021 7:39 pm
Forum: OpenSim
Topic: OpenSim 4.2: Matlab crash when reading C3D
Replies: 5
Views: 794

Re: OpenSim 4.2: Matlab crash when reading C3D

Dear Ton and Ayman, I have had a look at the provided file and found that the reason it fails is because Motion Analyses did not provide a calibration matrix (the parameter is present in the C3D, but is completely empty). Since I did not face this problem before, it was not taken into account in ezc...
by Benjamin Michaud
Fri Oct 16, 2020 1:22 pm
Forum: OpenSim
Topic: Force plate data for ground Reaction force
Replies: 1
Views: 767

Re: Force plate data for ground Reaction force

Dear Abdullah, I am the programmer of ezc3d so I had to code all this things already to make the force platform module, so hopefully I can provide you with some insights :) The relation between Force, Moment and CoP is as follow: Moment = F ^ CoP + Tz Where, ^ is the cross product, and Tz is the [0;...
by Benjamin Michaud
Thu Oct 25, 2018 3:18 pm
Forum: 2018 Fall OpenSim Virtual Workshop
Topic: Seth model availabilty [SOLVED]
Replies: 4
Views: 1452

Re: Seth model availabilty

We were actually looking for a full upper limb model with muscles and hoping yours was ready already! We are looking forward trying your model.

Regards
by Benjamin Michaud
Wed Oct 24, 2018 2:43 pm
Forum: 2018 Fall OpenSim Virtual Workshop
Topic: Units for setQ [SOLVED]
Replies: 2
Views: 464

Re: Units for setQ

Sweet thanks
by Benjamin Michaud
Wed Oct 24, 2018 2:17 pm
Forum: 2018 Fall OpenSim Virtual Workshop
Topic: Kinematics in python
Replies: 3
Views: 605

Re: Kinematics in python

Hi Najoua, We have just figure out how! So after loading a mot file, you have to compute spline for each coordinate, idealy filter it and then evaluate values at each time. That would look something like this : # Prepare a model model = osim.Model(model_path) state = model.initSystem() working_state...
by Benjamin Michaud
Wed Oct 24, 2018 1:22 pm
Forum: 2018 Fall OpenSim Virtual Workshop
Topic: Kinematics in python
Replies: 3
Views: 605

Re: Kinematics in python

Hello, We have the same problem, from this piece of code we get up to loading coordinate states from a file, but we can't figure out how to derivate it properly model = osim.Model(model_path) state = model.initSystem() working_state = model.updWorkingState() # Read the data data_storage = osim.Stora...
by Benjamin Michaud
Wed Oct 24, 2018 12:39 pm
Forum: 2018 Fall OpenSim Virtual Workshop
Topic: Units for setQ [SOLVED]
Replies: 2
Views: 464

Units for setQ [SOLVED]

Hello! I am getting Q from a mot file produced by inverse kinematics. The values are given in degrees. I just wanted to be sure that when I populate the state using the state.setQ(Q) method [in python], it actually waits for degrees and not radian. If it waits for radian, is there a function that co...