Section 3

Quickstart

Pick the norm and what you want to measure. The snippet updates to a complete, runnable program that reads joints from URDF files, and every combination is executed against the sample data before it is published. To score joints from another format, build the endpoint pairs with screw_twist and make_endpoint_pair instead of load_joint (see the API reference).

The distance is 0 exactly when the two sides induce the same motion, and it is a true metric: symmetric, with the triangle inequality, and invariant to the sign of the axis and to which limit is called lower. E_α is dimensionless, E_B is in meters, E^ϕ is dimensionless and bounded, and E^tree sums joint costs over an optimal matching. The core concepts pages explain each choice with a figure, and the API reference lists every function.