Class: Graphunk::WeightedDirectedGraph

Inherits:
WeightedGraph show all
Defined in:
lib/graphunk/weighted_directed_graph.rb

Instance Attribute Summary

Attributes inherited from WeightedGraph

#weights

Instance Method Summary collapse

Methods inherited from WeightedGraph

#initialize

Methods inherited from Graph

#add_vertex, #add_vertices, #edges, #edges_on_vertex, #initialize, #remove_vertex, #vertex_exists?, #vertices

Constructor Details

This class inherits a constructor from Graphunk::WeightedGraph

Instance Method Details

#add_edge(v, u, w) ⇒ Object 



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# File 'lib/graphunk/weighted_directed_graph.rb', line 4

def add_edge(v, u, w)
  if edge_exists?(v, u)
    raise ArgumentError, "This edge already exists"
  elsif vertex_exists?(v) && vertex_exists?(u)
    @representation[v] << u
    @weights[[v,u]] = w
  else
    raise ArgumentError, "One of the vertices referenced does not exist in the graph"
  end
end

#adjust_weight(v, u, w) ⇒ Object 



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# File 'lib/graphunk/weighted_directed_graph.rb', line 32

def adjust_weight(v, u, w)
  if edge_exists?(v, u)
    @weights[[v,u]] = w
  else
    raise ArgumentError, "That edge does not exist in the graph"
  end
end

#edge_weight(v, u) ⇒ Object 



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# File 'lib/graphunk/weighted_directed_graph.rb', line 24

def edge_weight(v, u)
  if edge_exists?(v,u)
    @weights[[v,u]]
  else
    raise ArgumentError, "That edge does not exist in the graph"
  end
end

#neighbors_of_vertex(v) ⇒ Object 



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# File 'lib/graphunk/weighted_directed_graph.rb', line 40

def neighbors_of_vertex(v)
  if vertex_exists?(v)
    @representation[v]
  else
    raise ArgumentError, "That vertex does not exist in the graph"
  end
end

#remove_edge(v, u) ⇒ Object 



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# File 'lib/graphunk/weighted_directed_graph.rb', line 15

def remove_edge(v, u)
  if edge_exists?(v, u)
    @representation[v].delete(u)
    @weights.delete([v,u])
  else
    raise ArgumentError, "That edge does not exist in the graph"
  end
end

#shortest_path(v, u) ⇒ Object 



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# File 'lib/graphunk/weighted_directed_graph.rb', line 56

def shortest_path(v, u)
  if vertex_exists?(u)
    [].tap do |s|
      previous = single_source_shortest_path_previous(v)
      while previous[u]
        s.insert(0, u)
        u = previous[u]
      end
      s.insert(0, v)
    end
  else
    raise ArgumentError, "A specified vertex does not exist in the graph"
  end
end

#shortest_path_distance(v, u) ⇒ Object 



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# File 'lib/graphunk/weighted_directed_graph.rb', line 48

def shortest_path_distance(v, u)
  if vertex_exists?(u)
    single_source_shortest_path_distances(v)[u]
  else
    raise ArgumentError, "A specified vertex does not exist in the graph"
  end
end