A centre, a radius per axis, and a soft outer shell. More...
#include <FeatureExtent.hpp>
Collaboration diagram for MayaFlux::Kinesis::EllipsoidExtent:Public Attributes | |
| Eigen::VectorXd | centre |
| Prototype point. | |
| Eigen::VectorXd | radii |
| Per-axis extent at which normalized distance reaches one. | |
| double | softness { 0.0 } |
| Additional normalized distance over which membership falls to zero. | |
Detailed Description
A centre, a radius per axis, and a soft outer shell.
The graded case: distance from a prototype rather than satisfaction of independent bands. Radii are per axis so an ellipsoid derived from observed spread is tighter on the axes that were consistent across observations and looser on the ones that were not, which is the behaviour a extent fitted from demonstrations should have.
Axis-aligned rather than fully general: a full covariance ellipsoid needs an eigendecomposition to test membership and correlated feature axes are usually a sign that the axes were badly chosen rather than something to model.
The closer analog elsewhere is Nexus::Presence::FalloffFn, which also maps a normalized distance to a weight. The two differ in what "normalized distance" means and in whether an inside exists at all. Presence radiates outward from a point in 3D world space with no hard boundary, weight one at the centre falling toward zero at the falloff radius. This has a genuine inside, membership exactly one for any point within the per-axis radii, and softness only describes the outer shell beyond that. A Presence has no analog of "fully inside".
Definition at line 155 of file FeatureExtent.hpp.
The documentation for this struct was generated from the following file:
