Silvio Traversaro

This also computes as a by-product the time derivative of the mass matrix, right? This may be of interest of @rob-mau .

The example is failing with the following error for me: ~~~ traversaro@IITBMP014LW012:~/jaxsimws$ pixi run python mwe103.py jaxsim[21436] INFO Enabling JAX to use 64bit precision An NVIDIA GPU may be present...

Playing a bit around, I was able to reduce the MWE, to remove jaxsim at all: ~~~python import dataclasses import jax import jax.numpy as jnp import jax_dataclasses from jax_dataclasses import...

> Somehow the problem is related to the `body` attribute of the `GroundContact` class: This is aligned with what was found in https://github.com/ami-iit/jaxsim/issues/84#issuecomment-1943719169 .

I think the answer to this question clarifies everything: https://github.com/google/jax/issues/19547#issuecomment-1913711588 .

I think I described the root issue behind all the `ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()` in https://github.com/ami-iit/jaxsim/pull/105...

> Right now on `ErgoCubReduced` the jacobians that are not matching are the ones for the frames: > > * l_foot_front > > * l_foot_rear > > * l_hip_3 >...

> Here's the log containg the homogeneous trasnforms from world to frame that are failing: > Logs > > ``` > jaxsim[100706] ERROR Assertion failed for frame: l_foot_front > jaxsim[100706]...

> > Right now on `ErgoCubReduced` the jacobians that are not matching are the ones for the frames: > > ``` > > * l_foot_front > > > > *...

> Here's the result of the transform unit test using default pose, setted using > > ```python > data = js.data.JaxSimModelData.zero(model=model) > ``` > > Details > > ``` >...