Planar.PRandom persistent planar graphs
type graph = G.tval graph : ?loops:bool -> xrange:(int * int) -> yrange:(int * int) -> prob:float ->
int -> graphgraph xrange yrange prob v generates a random planar graph with exactly v vertices. Vertices are labeled with integer coordinates, randomly distributed according to xrange and yrange. Edges are built as follows: the full Delaunay triangulation is constructed and then each edge is discarded with probabiblity prob (which should lie in 0..1). In particular prob = 0.0 gives the full triangulation. Edges are labeled with the (rounded) Euclidean distance between the two vertices. The boolean loops indicates whether loops are allowed; default value is no loop (false).