Add a general hat function

[aerogjy]

Problem to solve

Add a general hat function to replace the current vec2skew

Further details

Besides so3, which has a 3x3 skew matrix, all the rest of se3, sim3, etc types have the the closed form representation of the hat matrix, which are used pretty often.

Proposal

For each Lie Type, create a corresponding hat function.

Documentation

Args: input (LieTensor): The input LieTensor (Lie algebra) Return: a matrix representing the hat operation

Testing

No risk.

[wang-chen]

Hi @aerogjy Are we still going to add this feature? Could you provide more mathematical details for this issue?