wolffd@0: % GENERAL GRAPH THEORY CLASS
wolffd@0: %
wolffd@0: % CAVE: Any special application oriented stuff 
wolffd@0: % should be outside here
wolffd@0: 
wolffd@0: classdef Graph < DiGraph
wolffd@0:  
wolffd@0: methods
wolffd@0: 
wolffd@0:     % ---
wolffd@0: % Constructor
wolffd@0: % ---
wolffd@0: function G = Graph(V, E)
wolffd@0:      
wolffd@0:     if nargin == 1
wolffd@0:         % ---
wolffd@0:         % this uses an imput grpaph
wolffd@0:         % to create a new graph
wolffd@0:         % ---
wolffd@0:         G = Graph.copy(V);
wolffd@0:         
wolffd@0:     elseif nargin == 2
wolffd@0:         
wolffd@0:         if numel(V) == size(V,2)
wolffd@0:             G.V = V;
wolffd@0:         else
wolffd@0:             G.V = V';
wolffd@0:         end
wolffd@0: 
wolffd@0:         G.E = E;
wolffd@0:     end
wolffd@0: end
wolffd@0: function w = edge(G, V1, V2)
wolffd@0:     
wolffd@0:     sm = min([V1, V2]);
wolffd@0:     bg = max([V1, V2]);
wolffd@0:     
wolffd@0:     w = G.E(sm, bg);
wolffd@0: end
wolffd@0: 
wolffd@0: % ---      
wolffd@0: % add an edge
wolffd@0: % the undirected case: G.E is triangular
wolffd@0: % ---
wolffd@0: function add_edge(G, V1, V2, weight)
wolffd@0:     
wolffd@0:     G.add_node(V1);
wolffd@0: 	G.add_node(V2);
wolffd@0:     
wolffd@0:     sm = min([V1, V2]);
wolffd@0:     bg = max([V1, V2]);
wolffd@0:     
wolffd@0:     if  G.E(sm, bg) == 0
wolffd@0: 
wolffd@0:         % save weight
wolffd@0:         G.E(sm, bg) = weight;
wolffd@0:     else
wolffd@0:         
wolffd@0:         join_edge(G, V1, V2, weight);
wolffd@0:     end
wolffd@0: end
wolffd@0: 
wolffd@0: % remove an edge
wolffd@0: function remove_edge(G, V1, V2)
wolffd@0:     
wolffd@0:     sm = min([V1, V2]);
wolffd@0:     bg = max([V1, V2]);
wolffd@0:     
wolffd@0:     G.E(sm,bg) = 0;
wolffd@0: end
wolffd@0: 
wolffd@0: % ---
wolffd@0: % sets the edge without considering earlier weights
wolffd@0: % ---
wolffd@0: function set_edge(G, V1, V2, weight)
wolffd@0:     
wolffd@0:     sm = min([V1, V2]);
wolffd@0:     bg = max([V1, V2]);
wolffd@0:     
wolffd@0:     G.E(sm, bg) = weight;
wolffd@0:     
wolffd@0: end
wolffd@0: 
wolffd@0: % ---
wolffd@0: % Graph-specific functions
wolffd@0: % in the undirected case, these are the same
wolffd@0: % ---
wolffd@0: function c = children(G, Vid)
wolffd@0: 
wolffd@0:     c = [find(G.E(Vid,:) > 0) find(G.E(:,Vid) > 0)'];
wolffd@0: end
wolffd@0: 
wolffd@0: function p = parents(G, Vid)
wolffd@0: 
wolffd@0:     p = [find(G.E(Vid,:) > 0) find(G.E(:,Vid) > 0)'];
wolffd@0: end
wolffd@0: 
wolffd@0: % ---
wolffd@0: % Vertex Degree
wolffd@0: % ---
wolffd@0: function out = degree(G, V)
wolffd@0:     
wolffd@0:     out = sum(G.E(V,:) > 0) + sum(G.E(:,V) > 0);
wolffd@0: end
wolffd@0: 
wolffd@0: % ---
wolffd@0: % Vertex Degree
wolffd@0: % ---
wolffd@0: function out = degree_in(G, V)
wolffd@0:     
wolffd@0:     out = sum(G.E(V,:) > 0) + sum(G.E(:,V) > 0);
wolffd@0: end
wolffd@0: 
wolffd@0: % ---
wolffd@0: % Vertex Degree
wolffd@0: % ---
wolffd@0: function out = degree_out(G, V)
wolffd@0:     
wolffd@0:     out = sum(G.E(:,V) > 0) + sum(G.E(:,V) > 0);
wolffd@0: end
wolffd@0: 
wolffd@0: end
wolffd@0: 
wolffd@0: 
wolffd@0: methods (Static)
wolffd@0:    function G = copy(Gin)
wolffd@0:        
wolffd@0:        if strcmp(class(Gin), 'Graph')
wolffd@0:            
wolffd@0:            G = Graph(Gin.V, Gin.E);
wolffd@0:            G.Vlbl = Gin.Vlbl;
wolffd@0:            
wolffd@0:        else
wolffd@0:            warning ('cannot copy graph, casting instead')
wolffd@0:            G = Graph.cast(Gin);
wolffd@0:        end
wolffd@0:         
wolffd@0:    end
wolffd@0:    
wolffd@0:    function G = cast(Gin)
wolffd@0:        
wolffd@0:         % ---
wolffd@0:         % this uses an imput grpaph
wolffd@0:         % to create a new digraph
wolffd@0:         % ---
wolffd@0:         G = Graph();
wolffd@0:         
wolffd@0:         % ---
wolffd@0:         % Add the input graph to the empty one
wolffd@0:         % ---
wolffd@0:         G.add_graph(Gin);
wolffd@0:    end
wolffd@0: end
wolffd@0: end