X-Git-Url: https://git.njae.me.uk/?a=blobdiff_plain;f=lib%2Fgraph.njae%2Fgraph.rb;h=acfc9e07e998ee3843aa19e990f7670d38a8bcce;hb=e3fe1f33fea019106289edfae4e7a32f3ba3e03b;hp=b1de59b324be4297ceed4ef6c1a8dd2fdfe890df;hpb=353a5d54ad4014af126c76617d9b02029a3ee98c;p=graph.njae.git

diff --git a/lib/graph.njae/graph.rb b/lib/graph.njae/graph.rb
index b1de59b..acfc9e0 100644
--- a/lib/graph.njae/graph.rb
+++ b/lib/graph.njae/graph.rb
@@ -24,18 +24,38 @@ module GraphNjae
       self
     end
     
+    # Connects two vertices, creating and storing a new edge
+    # Also adds the vertices, unless they're already in the graph
+    def connect(vertex1, vertex2)
+      self.vertices << vertex1 unless self.vertices.include? vertex1
+      self.vertices << vertex2 unless self.vertices.include? vertex2
+      edge = Edge.new
+      self.edges << edge
+      edge << vertex1 << vertex2
+    end
+    
     # Form a product graph of this graph and the other.
     # Return the new graph.
     def product(other)
       product_graph = Graph.new
       self.vertices.each do |v1|
         other.vertices.each do |v2|
-          product_vertex = Vertex.new
-          product_vertex.left_node = v1
-          product_vertex.right_node = v2
-          product_graph << product_vertex
+          product_graph << Vertex.new({:g1_vertex => v1, :g2_vertex => v2})
+        end
+      end
+      self.edges.each do |e1|
+        e1_vertices = e1.vertices
+        other.edges.each do |e2|
+          e2_vertices = e2.vertices
+          source = product_graph.vertices.find {|v| v.g1_vertex == e1_vertices[0] and v.g2_vertex == e2_vertices[0]}
+          destination = product_graph.vertices.find {|v| v.g1_vertex == e1_vertices[1] and v.g2_vertex == e2_vertices[1]}
+          product_graph.connect source, destination
+          source = product_graph.vertices.find {|v| v.g1_vertex == e1_vertices[0] and v.g2_vertex == e2_vertices[1]}
+          destination = product_graph.vertices.find {|v| v.g1_vertex == e1_vertices[1] and v.g2_vertex == e2_vertices[0]}
+          product_graph.connect source, destination
         end
       end
+      product_graph
     end
     
   end # class