btk_loadc3d returns undefined function or variable in Matlab R2022b

Dear Matlab Community,

I have taken a code from Opensim website (attached below) for initail testing which I intend to amend later for my use case. I wanted to run it and see the output to get a better understanding. I am using the opensim_walking_pipeline.m function from this project. I have given the requried path of opensim installation in the m-file as per installation fodler and on running the m-file, I select their own sample file form the correct location of the file in my computer.

The moment I then run it, it gives me the following error in line 30 of the script

Unrecognized function or variable 'btk_loadc3d'.

I assume I am mising something but I could not find a relaibale answer over the internet. The only relevant thread I found can be seen at

https://github.com/abboss/b-tk/issues/78

but, I am not sure if this is related to my case as I am using a very updated version of Matlab compared to Matlab 2009. Can anyone please guide how to solve this issue please?

Best Regards

Hasan

Answer 1

[Gyan Vaibhav]

Hi Ehtisham,

I downloaded the example and tried running the example myself, and got the same error. Just to make sure have you installed the btk library? This seems to be an old library which has not gotten any updates, since 2012. Run the following command to check if it has been installed properly.

help btk

If you haven't installed the btk library, please follow these guidelines, however you might face a few compatibility issues, which you might need to resolve to make it work.

1. Download the BTK source files from the following repo: https://github.com/Biomechanical-ToolKit/BTKCore
2. Follow this guide along to install, and make sure the prerequisite programs are installed to build the library : https://biomechanical-toolkit.github.io/docs/Wrapping/Matlab/_tutorial.html
3. Make sure you add the path of the installation, to the matlab list of folders to load using the "addpath" command.
4. Run the example again.

Hope this resolves your issue. However, I tried on my machine and wasn't able to resolve the compatibility issues.

Thanks

Gyan