NLCT is short for Non-Linear Covariance Transform library. It is a fast and lightweight library written in C++ to:

• convert the covariance matrices for poses between different representations: Quaternions, Euler Angle (both fixed and moving frames)
• compute the composition of multiple certain and uncertain poses
• transform the covariance of a pose from one coordinate frame into another

For all functions the user can choose the computation method: UNSCENTED, JACOBIAN, SAMPLING. The computation methods are a trade-off between accuracy and computation speed. The library includes functions for normalization, representation conversion and pose transformation (like composition, inversion etc.).