The spherical restricted distance kernel is defined by
\[ K(t) = -2\sin(\frac{\acos(t)}{2})\]
for \(t\in[0,1]\). This kernel is negative and describes the distance between two given vector3d's, by K.eval(dot(v_1,v_2)). It is used in the compactify method to ensure that the points repel each other and do not overlap.
Syntax
psi = S2RestrictedDistanceKernel(bw)Input
| bw | bandwidth |
Output
| psi | S2Kernel |