Compute the geometric graph $$x_i ~ x_j \Leftrightarrow ||x_i-x_j|| < r \& -\theta < angle(x_j-x_i) < \theta$$
Arguments
- x
matrix of location coordinates
- u
unit vector of direction
- theta
angle for the directed cone
- r
radius for neighbourhood
- from
default 1:nrow(x), indices of points from which to compute edges
- to
default 1:nrow(x), indices of points which account as potential neighbours
- double
use the double cone, i.e. look also in direction -u?
- pregraph
A list-of-neighbour indices where to look for potential neighbours