C3D export

[Mohammadreza Rezaie]

Dear Experts,

I have a problem in using python for OpenSim 4.1

My Anaconda is for python 2 (anaconda2),
I created a new environment for OpenSim 4.1 with python 3.7
The 4.1\bin folder is on my system path environment.
The codes are exactly the same as "Reading C3D files through Python"
in addition to importing os, opensim and numpy

But this error appears in that code:

(opensim41) C:\Users\MohammadReza\Desktop>python opensim41.py

Traceback (most recent call last):
File "opensim41.py", line 14, in <module>
tables = C3DFileAdapter.readFile(os.path.join(test_dir, 'walking2.c3d'), 1)
NameError: name 'C3DFileAdapter' is not defined

Would you please help me with this code and error?

Your help would be greatly appreciated.

Cheers

[Ayman Habib]

Hello,

The interface to C3DFileAdapter has changed, please consult the doxygen documentation here for available methods
https://simtk.org/api_docs/opensim/api_ ... apter.html

The class now uses the generic read method from its base class rather than a custom readFile method as of version 4.1

Best regards,
-Ayman

[Mohammadreza Rezaie]

Hi Aymen,

Many thanks for your reply.
Is there anything wrong with this new code?


import opensim
C3DFileAdapter c3dFileAdapter;
c3dFileAdapter.setLocationForForceExpression(opensim.C3DFileAdapter.ForceLocation_CenterOfPressure);
tables = c3dFileAdapter.read("walking5.c3d")
markers = tables['markers']
forces = tables['forces']



There is still an error:

(opensim41) C:\Users\MohammadReza\Desktop>python opensim41.py
File "opensim41.py", line 2
C3DFileAdapter c3dFileAdapter;
^
SyntaxError: invalid syntax



I execute this code in Anaconda Prompt and this is my python version:

(opensim41) C:\Users\MohammadReza\Desktop>python --version
Python 3.7.6


I'm grateful for your help
Cheers

[Thomas Uchida]

It looks like your code is part C++ and part Python. For reference, there's a related test case here: https://github.com/opensim-org/opensim- ... ter.py#L33. You should have something like this:

Code: Select all

import opensim
c3dFileAdapter = opensim.C3DFileAdapter()
...

[Mohammadreza Rezaie]

It looks like your code is part C++ and part Python.

Thanks Tom,

There is an example on doxygen for python:

1.JPG (19.68 KiB) Viewed 590 times

https://simtk.org/api_docs/opensim/api_ ... apter.html

But now it works well

Cheers

[Thomas Uchida]

Great. Thanks for reporting- I'll submit a fix.

[Mohammadreza Rezaie]

Hi,

It would be great if these examples become updated for 4.1 version as well.

https://simtk-confluence.stanford.edu:8 ... d%29+Files

Best Wishes

[Thomas Uchida]

Thanks for reporting. I've opened an Issue on GitHub (https://github.com/opensim-org/opensim-core/issues/2673) to investigate.

[Mohammadreza Rezaie]

Hi again,

In MATLAB, "rotateData" and "convertMillimeters2Meters" were defined
but in python, I can't find them. are there any examples of these
functions in python for "forces"?

adapter = opensim.C3DFileAdapter()
task = adapter.read(os.path.join(output_dir, 'task.c3d'))
forces = adapter.getForcesTable(task)

Your response would be greatly appreciated.

Cheers

[Thomas Uchida]

rotateData() and convertMillimeters2Meters() are functions written in Matlab (https://github.com/opensim-org/opensim- ... C3D.m#L138 and https://github.com/opensim-org/opensim- ... C3D.m#L154). You can implement them in Python if you need them there.