spatgraphs-spatgraph {spatgraphs}R Documentation

spatgraph

Description

Compute an adjacency list-of-lists for a given 2D- or 3D- point pattern.

Date: 2008-07-29
License: GPL v2 or later

Arguments

pp Point pattern with members x,y,n,window. Window must have x- and y-limits according to given x,y. see package 'spatstat', class 'ppp'.
type One of the supported graph types, see below.
par Parameter(s) for the graph, see below.
preprocessR If >0 first compute geometric graph and then the 'type' graph using the preprocessed edgelist. Useful to narrow the search space for bigger pp's.
dbg Boolean, print additional information of the execution.
doDists Boolean, default FALSE. If true, precompute the distance diagonal matrix. Speeds up quite a lot but takes O(n^2) memory!
toroidal Make a toroidal distance calculation. Not useful when visualizing but useful for edge correction in summary calculations.

Details

The following 'type' values are accepted, note that some of them need also the 'par':

'geometric' par=numeric>0. Geometric graph, par = connection radius.
'knn' par=integer>0. k-nearest neighbours graph, par = k.
'mass_geometric' Connect two points if ||x-y||<m(x).
'gabriel' Gabriel graph.
'delauney' Delauney triangulation. !Only 2D!
'MST' Minimal spanning tree.
'markcross' Connect two points if ||x-y||<m(x)+m(y).
'SIG' Spheres of Influence.
'RST' par=c(x0,y0,z0). Radial spanning tree, par=origin of radiation.
'RNG' Relative neighbourhood graph.
'CCC' par=integer (or string). Class-Cover-Catch, par=target type.
'STIR' par=c(noise,alpha,beta,gamma). Signal-To-Noise-Ratio, par: background noise, signal attenuation (1/r^alpha), signal threshold beta, interference tolerance gamma. See ref 1.

where

 m(x) ~ real valued mark for x (size, mass, diameter, transmission power...)
The graphs 'mass_geometric', 'markcross' and 'STIR' use scalar marks, 'CCC' class marks (e.g. integer). If given 'pp' has no marks it will be marked with 1.0's.

References

Dousse, O., Baccelli, F. & Thiran, P.: Impact of Interferences on Connectivity in Ad Hoc Networks. IEEE/ACM Transactions on Networking,13 (2),p. 425-436,2005.

Marchette, D.: Random Graphs for Statistical Pattern Recognition, Wiley 2004.


[Package spatgraphs version 2.1 Index]