any example about the gradient calculation?

[foolyc]

is there any demo about calculating the gradient of system output q, q_{dot} with respect to physical properties parameters(link length/ mass/ inertia...) in python?

[erwincoumans]

Only the C++ has gradients, the Python bindings don't expose the gradients yet. It will be exposed.

[erwincoumans]

Latest version has pytinydiffsim_dual using dual numbers (forward mode).
There is a trivial example here:
https://github.com/google-research/tiny-differentiable-simulator/blob/master/python/examples/z_dual_numbers.py

The current code is also uploaded to pypi as revision 0.0.3, on Windows or Linux you can use

pip3 install pytinydiffsim --upgrade --user

Will look into a more interesting example later.